// expressions.cc -- Go frontend expression handling. // Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. #include "go-system.h" #include #include "go-c.h" #include "gogo.h" #include "go-diagnostics.h" #include "go-encode-id.h" #include "types.h" #include "export.h" #include "import.h" #include "statements.h" #include "lex.h" #include "runtime.h" #include "backend.h" #include "expressions.h" #include "ast-dump.h" // Class Expression. Expression::Expression(Expression_classification classification, Location location) : classification_(classification), location_(location) { } Expression::~Expression() { } // Traverse the expressions. int Expression::traverse(Expression** pexpr, Traverse* traverse) { Expression* expr = *pexpr; if ((traverse->traverse_mask() & Traverse::traverse_expressions) != 0) { int t = traverse->expression(pexpr); if (t == TRAVERSE_EXIT) return TRAVERSE_EXIT; else if (t == TRAVERSE_SKIP_COMPONENTS) return TRAVERSE_CONTINUE; } return expr->do_traverse(traverse); } // Traverse subexpressions of this expression. int Expression::traverse_subexpressions(Traverse* traverse) { return this->do_traverse(traverse); } // A traversal used to set the location of subexpressions. class Set_location : public Traverse { public: Set_location(Location loc) : Traverse(traverse_expressions), loc_(loc) { } int expression(Expression** pexpr); private: Location loc_; }; // Set the location of an expression. int Set_location::expression(Expression** pexpr) { // Some expressions are shared or don't have an independent // location, so we shouldn't change their location. This is the set // of expressions for which do_copy is just "return this" or // otherwise does not pass down the location. switch ((*pexpr)->classification()) { case Expression::EXPRESSION_ERROR: case Expression::EXPRESSION_VAR_REFERENCE: case Expression::EXPRESSION_ENCLOSED_VAR_REFERENCE: case Expression::EXPRESSION_STRING: case Expression::EXPRESSION_FUNC_DESCRIPTOR: case Expression::EXPRESSION_TYPE: case Expression::EXPRESSION_BOOLEAN: case Expression::EXPRESSION_CONST_REFERENCE: case Expression::EXPRESSION_NIL: case Expression::EXPRESSION_TYPE_DESCRIPTOR: case Expression::EXPRESSION_GC_SYMBOL: case Expression::EXPRESSION_PTRMASK_SYMBOL: case Expression::EXPRESSION_TYPE_INFO: case Expression::EXPRESSION_STRUCT_FIELD_OFFSET: return TRAVERSE_CONTINUE; default: break; } (*pexpr)->location_ = this->loc_; return TRAVERSE_CONTINUE; } // Set the location of an expression and its subexpressions. void Expression::set_location(Location loc) { this->location_ = loc; Set_location sl(loc); this->traverse_subexpressions(&sl); } // Default implementation for do_traverse for child classes. int Expression::do_traverse(Traverse*) { return TRAVERSE_CONTINUE; } // This virtual function is called by the parser if the value of this // expression is being discarded. By default, we give an error. // Expressions with side effects override. bool Expression::do_discarding_value() { this->unused_value_error(); return false; } // This virtual function is called to export expressions. This will // only be used by expressions which may be constant. void Expression::do_export(Export_function_body*) const { go_unreachable(); } // Write a name to the export data. void Expression::export_name(Export_function_body* efb, const Named_object* no) { if (no->package() != NULL) { char buf[50]; snprintf(buf, sizeof buf, "", efb->package_index(no->package())); efb->write_c_string(buf); } if (!Gogo::is_hidden_name(no->name())) efb->write_string(no->name()); else { efb->write_c_string("."); efb->write_string(Gogo::unpack_hidden_name(no->name())); } } // Give an error saying that the value of the expression is not used. void Expression::unused_value_error() { if (this->type()->is_error()) { go_assert(saw_errors()); this->set_is_error(); } else this->report_error(_("value computed is not used")); } // Note that this expression is an error. This is called by children // when they discover an error. void Expression::set_is_error() { this->classification_ = EXPRESSION_ERROR; } // For children to call to report an error conveniently. void Expression::report_error(const char* msg) { go_error_at(this->location_, "%s", msg); this->set_is_error(); } // Set types of variables and constants. This is implemented by the // child class. void Expression::determine_type(const Type_context* context) { this->do_determine_type(context); } // Set types when there is no context. void Expression::determine_type_no_context() { Type_context context; this->do_determine_type(&context); } // Return true if two expressions refer to the same variable or struct // field. This can only be true when there are no side effects. bool Expression::is_same_variable(Expression* a, Expression* b) { if (a->classification() != b->classification()) return false; Var_expression* av = a->var_expression(); if (av != NULL) return av->named_object() == b->var_expression()->named_object(); Field_reference_expression* af = a->field_reference_expression(); if (af != NULL) { Field_reference_expression* bf = b->field_reference_expression(); return (af->field_index() == bf->field_index() && Expression::is_same_variable(af->expr(), bf->expr())); } Unary_expression* au = a->unary_expression(); if (au != NULL) { Unary_expression* bu = b->unary_expression(); return (au->op() == OPERATOR_MULT && bu->op() == OPERATOR_MULT && Expression::is_same_variable(au->operand(), bu->operand())); } Array_index_expression* aie = a->array_index_expression(); if (aie != NULL) { Array_index_expression* bie = b->array_index_expression(); return (aie->end() == NULL && bie->end() == NULL && Expression::is_same_variable(aie->array(), bie->array()) && Expression::is_same_variable(aie->start(), bie->start())); } Numeric_constant aval; if (a->numeric_constant_value(&aval)) { Numeric_constant bval; if (b->numeric_constant_value(&bval)) return aval.equals(bval); } return false; } // Return an expression handling any conversions which must be done during // assignment. Expression* Expression::convert_for_assignment(Gogo* gogo, Type* lhs_type, Expression* rhs, Location location) { Type* rhs_type = rhs->type(); if (lhs_type->is_error() || rhs_type->is_error() || rhs->is_error_expression()) return Expression::make_error(location); bool are_identical = Type::are_identical(lhs_type, rhs_type, (Type::COMPARE_ERRORS | Type::COMPARE_TAGS), NULL); if (!are_identical && lhs_type->interface_type() != NULL) { // Type to interface conversions have been made explicit early. go_assert(rhs_type->interface_type() != NULL); return Expression::convert_interface_to_interface(lhs_type, rhs, false, location); } else if (!are_identical && rhs_type->interface_type() != NULL) return Expression::convert_interface_to_type(gogo, lhs_type, rhs, location); else if (lhs_type->is_slice_type() && rhs_type->is_nil_type()) { // Assigning nil to a slice. Expression* nil = Expression::make_nil(location); Expression* zero = Expression::make_integer_ul(0, NULL, location); return Expression::make_slice_value(lhs_type, nil, zero, zero, location); } else if (rhs_type->is_nil_type()) return Expression::make_nil(location); else if (are_identical) { if (lhs_type->forwarded() != rhs_type->forwarded()) { // Different but identical types require an explicit // conversion. This happens with type aliases. return Expression::make_cast(lhs_type, rhs, location); } // No conversion is needed. return rhs; } else if (lhs_type->points_to() != NULL) return Expression::make_unsafe_cast(lhs_type, rhs, location); else if (lhs_type->is_numeric_type()) return Expression::make_cast(lhs_type, rhs, location); else if ((lhs_type->struct_type() != NULL && rhs_type->struct_type() != NULL) || (lhs_type->array_type() != NULL && rhs_type->array_type() != NULL)) { // This conversion must be permitted by Go, or we wouldn't have // gotten here. return Expression::make_unsafe_cast(lhs_type, rhs, location); } else return rhs; } // Return an expression for a conversion from a non-interface type to an // interface type. If ON_STACK is true, it can allocate the storage on // stack. Expression* Expression::convert_type_to_interface(Type* lhs_type, Expression* rhs, bool on_stack, Location location) { Interface_type* lhs_interface_type = lhs_type->interface_type(); bool lhs_is_empty = lhs_interface_type->is_empty(); // Since RHS_TYPE is a static type, we can create the interface // method table at compile time. // When setting an interface to nil, we just set both fields to // NULL. Type* rhs_type = rhs->type(); if (rhs_type->is_nil_type()) { Expression* nil = Expression::make_nil(location); return Expression::make_interface_value(lhs_type, nil, nil, location); } // This should have been checked already. if (!lhs_interface_type->implements_interface(rhs_type, NULL)) { go_assert(saw_errors()); return Expression::make_error(location); } // An interface is a tuple. If LHS_TYPE is an empty interface type, // then the first field is the type descriptor for RHS_TYPE. // Otherwise it is the interface method table for RHS_TYPE. Expression* first_field; if (lhs_is_empty) first_field = Expression::make_type_descriptor(rhs_type, location); else { // Build the interface method table for this interface and this // object type: a list of function pointers for each interface // method. Named_type* rhs_named_type = rhs_type->named_type(); Struct_type* rhs_struct_type = rhs_type->struct_type(); bool is_pointer = false; if (rhs_named_type == NULL && rhs_struct_type == NULL) { rhs_named_type = rhs_type->deref()->named_type(); rhs_struct_type = rhs_type->deref()->struct_type(); is_pointer = true; } if (rhs_named_type != NULL) first_field = rhs_named_type->interface_method_table(lhs_interface_type, is_pointer); else if (rhs_struct_type != NULL) first_field = rhs_struct_type->interface_method_table(lhs_interface_type, is_pointer); else first_field = Expression::make_nil(location); } Expression* obj; if (rhs_type->is_direct_iface_type()) { // We are assigning a pointer to the interface; the interface // holds the pointer itself. obj = unpack_direct_iface(rhs, location); } else { // We are assigning a non-pointer value to the interface; the // interface gets a copy of the value in the heap if it escapes. // An exception is &global if global is notinheap, which is a // pointer value but not a direct-iface type and we can't simply // take its address. bool is_address = (rhs->unary_expression() != NULL && rhs->unary_expression()->op() == OPERATOR_AND); if (rhs->is_constant() && !is_address) obj = Expression::make_unary(OPERATOR_AND, rhs, location); else { obj = Expression::make_heap_expression(rhs, location); if (on_stack) obj->heap_expression()->set_allocate_on_stack(); } } return Expression::make_interface_value(lhs_type, first_field, obj, location); } // Return an expression for the pointer-typed value of a direct interface // type. Specifically, for single field struct or array, get the single // field, and do this recursively. The reason for this is that we don't // want to assign a struct or an array to a pointer-typed field. The // backend may not like that. Expression* Expression::unpack_direct_iface(Expression* rhs, Location loc) { Struct_type* st = rhs->type()->struct_type(); if (st != NULL) { go_assert(st->field_count() == 1); Expression* field = Expression::make_field_reference(rhs, 0, loc); return unpack_direct_iface(field, loc); } Array_type* at = rhs->type()->array_type(); if (at != NULL) { int64_t len; bool ok = at->int_length(&len); go_assert(ok && len == 1); Type* int_type = Type::lookup_integer_type("int"); Expression* index = Expression::make_integer_ul(0, int_type, loc); Expression* elem = Expression::make_array_index(rhs, index, NULL, NULL, loc); return unpack_direct_iface(elem, loc); } return rhs; } // The opposite of unpack_direct_iface. Expression* Expression::pack_direct_iface(Type* t, Expression* rhs, Location loc) { if (rhs->type() == t) return rhs; Struct_type* st = t->struct_type(); if (st != NULL) { Expression_list* vals = new Expression_list(); vals->push_back(pack_direct_iface(st->field(0)->type(), rhs, loc)); return Expression::make_struct_composite_literal(t, vals, loc); } Array_type* at = t->array_type(); if (at != NULL) { Expression_list* vals = new Expression_list(); vals->push_back(pack_direct_iface(at->element_type(), rhs, loc)); return Expression::make_array_composite_literal(t, vals, loc); } return Expression::make_unsafe_cast(t, rhs, loc); } // Return an expression for the type descriptor of RHS. Expression* Expression::get_interface_type_descriptor(Expression* rhs) { go_assert(rhs->type()->interface_type() != NULL); Location location = rhs->location(); // The type descriptor is the first field of an empty interface. if (rhs->type()->interface_type()->is_empty()) return Expression::make_interface_info(rhs, INTERFACE_INFO_TYPE_DESCRIPTOR, location); Expression* mtable = Expression::make_interface_info(rhs, INTERFACE_INFO_METHODS, location); Expression* descriptor = Expression::make_dereference(mtable, NIL_CHECK_NOT_NEEDED, location); descriptor = Expression::make_field_reference(descriptor, 0, location); Expression* nil = Expression::make_nil(location); Expression* eq = Expression::make_binary(OPERATOR_EQEQ, mtable, nil, location); return Expression::make_conditional(eq, nil, descriptor, location); } // Return an expression for the conversion of an interface type to an // interface type. Expression* Expression::convert_interface_to_interface(Type *lhs_type, Expression* rhs, bool for_type_guard, Location location) { if (Type::are_identical(lhs_type, rhs->type(), Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) return rhs; Interface_type* lhs_interface_type = lhs_type->interface_type(); bool lhs_is_empty = lhs_interface_type->is_empty(); // In the general case this requires runtime examination of the type // method table to match it up with the interface methods. // FIXME: If all of the methods in the right hand side interface // also appear in the left hand side interface, then we don't need // to do a runtime check, although we still need to build a new // method table. // We are going to evaluate RHS multiple times. go_assert(rhs->is_multi_eval_safe()); // Get the type descriptor for the right hand side. This will be // NULL for a nil interface. Expression* rhs_type_expr = Expression::get_interface_type_descriptor(rhs); Expression* lhs_type_expr = Expression::make_type_descriptor(lhs_type, location); Expression* first_field; if (for_type_guard) { // A type assertion fails when converting a nil interface. first_field = Runtime::make_call(Runtime::ASSERTITAB, location, 2, lhs_type_expr, rhs_type_expr); } else if (lhs_is_empty) { // A conversion to an empty interface always succeeds, and the // first field is just the type descriptor of the object. first_field = rhs_type_expr; } else { // A conversion to a non-empty interface may fail, but unlike a // type assertion converting nil will always succeed. first_field = Runtime::make_call(Runtime::REQUIREITAB, location, 2, lhs_type_expr, rhs_type_expr); } // The second field is simply the object pointer. Expression* obj = Expression::make_interface_info(rhs, INTERFACE_INFO_OBJECT, location); return Expression::make_interface_value(lhs_type, first_field, obj, location); } // Return an expression for the conversion of an interface type to a // non-interface type. Expression* Expression::convert_interface_to_type(Gogo* gogo, Type *lhs_type, Expression* rhs, Location location) { // We are going to evaluate RHS multiple times. go_assert(rhs->is_multi_eval_safe()); // Build an expression to check that the type is valid. It will // panic with an appropriate runtime type error if the type is not // valid. // (lhs_type == rhs_type ? nil /*dummy*/ : // panicdottype(lhs_type, rhs_type, inter_type)) // For some Oses, we need to call runtime.eqtype instead of // lhs_type == rhs_type, as we may have unmerged type descriptors // from shared libraries. Expression* lhs_type_expr = Expression::make_type_descriptor(lhs_type, location); Expression* rhs_descriptor = Expression::get_interface_type_descriptor(rhs); Type* rhs_type = rhs->type(); Expression* rhs_inter_expr = Expression::make_type_descriptor(rhs_type, location); Expression* cond; if (gogo->need_eqtype()) { cond = Runtime::make_call(Runtime::EQTYPE, location, 2, lhs_type_expr, rhs_descriptor); } else { cond = Expression::make_binary(OPERATOR_EQEQ, lhs_type_expr, rhs_descriptor, location); } rhs_descriptor = Expression::get_interface_type_descriptor(rhs); Expression* panic = Runtime::make_call(Runtime::PANICDOTTYPE, location, 3, lhs_type_expr->copy(), rhs_descriptor, rhs_inter_expr); Expression* nil = Expression::make_nil(location); Expression* check = Expression::make_conditional(cond, nil, panic, location); // If the conversion succeeds, pull out the value. Expression* obj = Expression::make_interface_info(rhs, INTERFACE_INFO_OBJECT, location); // If the value is a direct interface, then it is the value we want. // Otherwise it points to the value. if (lhs_type->is_direct_iface_type()) obj = Expression::pack_direct_iface(lhs_type, obj, location); else { obj = Expression::make_unsafe_cast(Type::make_pointer_type(lhs_type), obj, location); obj = Expression::make_dereference(obj, NIL_CHECK_NOT_NEEDED, location); } return Expression::make_compound(check, obj, location); } // Convert an expression to its backend representation. This is implemented by // the child class. Not that it is not in general safe to call this multiple // times for a single expression, but that we don't catch such errors. Bexpression* Expression::get_backend(Translate_context* context) { // The child may have marked this expression as having an error. if (this->classification_ == EXPRESSION_ERROR) { go_assert(saw_errors()); return context->backend()->error_expression(); } return this->do_get_backend(context); } // Return a backend expression for VAL. Bexpression* Expression::backend_numeric_constant_expression(Translate_context* context, Numeric_constant* val) { Gogo* gogo = context->gogo(); Type* type = val->type(); if (type == NULL) return gogo->backend()->error_expression(); Btype* btype = type->get_backend(gogo); Bexpression* ret; if (type->integer_type() != NULL) { mpz_t ival; if (!val->to_int(&ival)) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } ret = gogo->backend()->integer_constant_expression(btype, ival); mpz_clear(ival); } else if (type->float_type() != NULL) { mpfr_t fval; if (!val->to_float(&fval)) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } ret = gogo->backend()->float_constant_expression(btype, fval); mpfr_clear(fval); } else if (type->complex_type() != NULL) { mpc_t cval; if (!val->to_complex(&cval)) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } ret = gogo->backend()->complex_constant_expression(btype, cval); mpc_clear(cval); } else go_unreachable(); return ret; } // Insert bounds checks for an index expression. Check that that VAL // >= 0 and that it fits in an int. Then check that VAL OP BOUND is // true. If any condition is false, call one of the CODE runtime // functions, which will panic. void Expression::check_bounds(Expression* val, Operator op, Expression* bound, Runtime::Function code, Runtime::Function code_u, Runtime::Function code_extend, Runtime::Function code_extend_u, Statement_inserter* inserter, Location loc) { go_assert(val->is_multi_eval_safe()); go_assert(bound->is_multi_eval_safe()); Type* int_type = Type::lookup_integer_type("int"); int int_type_size = int_type->integer_type()->bits(); Type* val_type = val->type(); if (val_type->integer_type() == NULL) { go_assert(saw_errors()); return; } int val_type_size = val_type->integer_type()->bits(); bool val_is_unsigned = val_type->integer_type()->is_unsigned(); // Check that VAL >= 0. Expression* check = NULL; if (!val_is_unsigned) { Expression* zero = Expression::make_integer_ul(0, val_type, loc); check = Expression::make_binary(OPERATOR_GE, val->copy(), zero, loc); } // If VAL's type is larger than int, check that VAL fits in an int. if (val_type_size > int_type_size || (val_type_size == int_type_size && val_is_unsigned)) { mpz_t one; mpz_init_set_ui(one, 1UL); // maxval = 2^(int_type_size - 1) - 1 mpz_t maxval; mpz_init(maxval); mpz_mul_2exp(maxval, one, int_type_size - 1); mpz_sub_ui(maxval, maxval, 1); Expression* max = Expression::make_integer_z(&maxval, val_type, loc); mpz_clear(one); mpz_clear(maxval); Expression* cmp = Expression::make_binary(OPERATOR_LE, val->copy(), max, loc); if (check == NULL) check = cmp; else check = Expression::make_binary(OPERATOR_ANDAND, check, cmp, loc); } // For the final check we can assume that VAL fits in an int. Expression* ival; if (val_type == int_type) ival = val->copy(); else ival = Expression::make_cast(int_type, val->copy(), loc); // BOUND is assumed to fit in an int. Either it comes from len or // cap, or it was checked by an earlier call. Expression* ibound; if (bound->type() == int_type) ibound = bound->copy(); else ibound = Expression::make_cast(int_type, bound->copy(), loc); Expression* cmp = Expression::make_binary(op, ival, ibound, loc); if (check == NULL) check = cmp; else check = Expression::make_binary(OPERATOR_ANDAND, check, cmp, loc); Runtime::Function c; if (val_type_size > int_type_size) { if (val_is_unsigned) c = code_extend_u; else c = code_extend; } else { if (val_is_unsigned) c = code_u; else c = code; } Expression* ignore = Expression::make_boolean(true, loc); Expression* crash = Runtime::make_call(c, loc, 2, val->copy(), bound->copy()); Expression* cond = Expression::make_conditional(check, ignore, crash, loc); inserter->insert(Statement::make_statement(cond, true)); } void Expression::dump_expression(Ast_dump_context* ast_dump_context) const { this->do_dump_expression(ast_dump_context); } // Error expressions. This are used to avoid cascading errors. class Error_expression : public Expression { public: Error_expression(Location location) : Expression(EXPRESSION_ERROR, location) { } protected: bool do_is_constant() const { return true; } bool do_numeric_constant_value(Numeric_constant* nc) const { nc->set_unsigned_long(NULL, 0); return true; } bool do_discarding_value() { return true; } Type* do_type() { return Type::make_error_type(); } void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } bool do_is_addressable() const { return true; } Bexpression* do_get_backend(Translate_context* context) { return context->backend()->error_expression(); } void do_dump_expression(Ast_dump_context*) const; }; // Dump the ast representation for an error expression to a dump context. void Error_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "_Error_" ; } Expression* Expression::make_error(Location location) { return new Error_expression(location); } // An expression which is really a type. This is used during parsing. // It is an error if these survive after lowering. class Type_expression : public Expression { public: Type_expression(Type* type, Location location) : Expression(EXPRESSION_TYPE, location), type_(type) { } protected: int do_traverse(Traverse* traverse) { return Type::traverse(this->type_, traverse); } Type* do_type() { return this->type_; } void do_determine_type(const Type_context*) { } void do_check_types(Gogo*); Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context*) { go_unreachable(); } void do_dump_expression(Ast_dump_context*) const; private: // The type which we are representing as an expression. Type* type_; }; void Type_expression::do_check_types(Gogo*) { if (this->type_->is_error()) { go_assert(saw_errors()); this->set_is_error(); } else this->report_error(_("invalid use of type")); } void Type_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_type(this->type_); } Expression* Expression::make_type(Type* type, Location location) { return new Type_expression(type, location); } // Class Parser_expression. Type* Parser_expression::do_type() { // We should never really ask for the type of a Parser_expression. // However, it can happen, at least when we have an invalid const // whose initializer refers to the const itself. In that case we // may ask for the type when lowering the const itself. go_assert(saw_errors()); return Type::make_error_type(); } // Class Var_expression. // Lower a variable expression. Here we just make sure that the // initialization expression of the variable has been lowered. This // ensures that we will be able to determine the type of the variable // if necessary. Expression* Var_expression::do_lower(Gogo* gogo, Named_object* function, Statement_inserter* inserter, int) { if (this->variable_->is_variable()) { Variable* var = this->variable_->var_value(); // This is either a local variable or a global variable. A // reference to a variable which is local to an enclosing // function will be a reference to a field in a closure. if (var->is_global()) { function = NULL; inserter = NULL; } var->lower_init_expression(gogo, function, inserter); } return this; } // Return the type of a reference to a variable. Type* Var_expression::do_type() { if (this->variable_->is_variable()) return this->variable_->var_value()->type(); else if (this->variable_->is_result_variable()) return this->variable_->result_var_value()->type(); else go_unreachable(); } // Determine the type of a reference to a variable. void Var_expression::do_determine_type(const Type_context*) { if (this->variable_->is_variable()) this->variable_->var_value()->determine_type(); } // Something takes the address of this variable. This means that we // may want to move the variable onto the heap. void Var_expression::do_address_taken(bool escapes) { if (!escapes) { if (this->variable_->is_variable()) this->variable_->var_value()->set_non_escaping_address_taken(); else if (this->variable_->is_result_variable()) this->variable_->result_var_value()->set_non_escaping_address_taken(); else go_unreachable(); } else { if (this->variable_->is_variable()) this->variable_->var_value()->set_address_taken(); else if (this->variable_->is_result_variable()) this->variable_->result_var_value()->set_address_taken(); else go_unreachable(); } if (this->variable_->is_variable() && this->variable_->var_value()->is_in_heap()) { Node::make_node(this)->set_encoding(Node::ESCAPE_HEAP); Node::make_node(this->variable_)->set_encoding(Node::ESCAPE_HEAP); } } // Export a reference to a variable. void Var_expression::do_export(Export_function_body* efb) const { Named_object* no = this->variable_; if (no->is_result_variable() || !no->var_value()->is_global()) efb->write_string(Gogo::unpack_hidden_name(no->name())); else Expression::export_name(efb, no); } // Get the backend representation for a reference to a variable. Bexpression* Var_expression::do_get_backend(Translate_context* context) { Bvariable* bvar = this->variable_->get_backend_variable(context->gogo(), context->function()); bool is_in_heap; Location loc = this->location(); Btype* btype; Gogo* gogo = context->gogo(); if (this->variable_->is_variable()) { is_in_heap = this->variable_->var_value()->is_in_heap(); btype = this->variable_->var_value()->type()->get_backend(gogo); } else if (this->variable_->is_result_variable()) { is_in_heap = this->variable_->result_var_value()->is_in_heap(); btype = this->variable_->result_var_value()->type()->get_backend(gogo); } else go_unreachable(); Bexpression* ret = context->backend()->var_expression(bvar, loc); if (is_in_heap) ret = context->backend()->indirect_expression(btype, ret, true, loc); return ret; } // Ast dump for variable expression. void Var_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << this->variable_->message_name() ; } // Make a reference to a variable in an expression. Expression* Expression::make_var_reference(Named_object* var, Location location) { if (var->is_sink()) return Expression::make_sink(location); // FIXME: Creating a new object for each reference to a variable is // wasteful. return new Var_expression(var, location); } // Class Enclosed_var_expression. int Enclosed_var_expression::do_traverse(Traverse*) { return TRAVERSE_CONTINUE; } // Lower the reference to the enclosed variable. Expression* Enclosed_var_expression::do_lower(Gogo* gogo, Named_object* function, Statement_inserter* inserter, int) { gogo->lower_expression(function, inserter, &this->reference_); return this; } // Flatten the reference to the enclosed variable. Expression* Enclosed_var_expression::do_flatten(Gogo* gogo, Named_object* function, Statement_inserter* inserter) { gogo->flatten_expression(function, inserter, &this->reference_); return this; } void Enclosed_var_expression::do_address_taken(bool escapes) { if (!escapes) { if (this->variable_->is_variable()) this->variable_->var_value()->set_non_escaping_address_taken(); else if (this->variable_->is_result_variable()) this->variable_->result_var_value()->set_non_escaping_address_taken(); else go_unreachable(); } else { if (this->variable_->is_variable()) this->variable_->var_value()->set_address_taken(); else if (this->variable_->is_result_variable()) this->variable_->result_var_value()->set_address_taken(); else go_unreachable(); } if (this->variable_->is_variable() && this->variable_->var_value()->is_in_heap()) Node::make_node(this->variable_)->set_encoding(Node::ESCAPE_HEAP); } // Ast dump for enclosed variable expression. void Enclosed_var_expression::do_dump_expression(Ast_dump_context* adc) const { adc->ostream() << this->variable_->message_name(); } // Make a reference to a variable within an enclosing function. Expression* Expression::make_enclosing_var_reference(Expression* reference, Named_object* var, Location location) { return new Enclosed_var_expression(reference, var, location); } // Class Temporary_reference_expression. // The type. Type* Temporary_reference_expression::do_type() { return this->statement_->type(); } // Called if something takes the address of this temporary variable. // We never have to move temporary variables to the heap, but we do // need to know that they must live in the stack rather than in a // register. void Temporary_reference_expression::do_address_taken(bool) { this->statement_->set_is_address_taken(); } // Export a reference to a temporary. void Temporary_reference_expression::do_export(Export_function_body* efb) const { unsigned int idx = efb->temporary_index(this->statement_); char buf[50]; snprintf(buf, sizeof buf, "$t%u", idx); efb->write_c_string(buf); } // Import a reference to a temporary. Expression* Temporary_reference_expression::do_import(Import_function_body* ifb, Location loc) { std::string id = ifb->read_identifier(); go_assert(id[0] == '$' && id[1] == 't'); const char *p = id.c_str(); char *end; long idx = strtol(p + 2, &end, 10); if (*end != '\0' || idx > 0x7fffffff) { if (!ifb->saw_error()) go_error_at(loc, ("invalid export data for %qs: " "invalid temporary reference index at %lu"), ifb->name().c_str(), static_cast(ifb->off())); ifb->set_saw_error(); return Expression::make_error(loc); } Temporary_statement* temp = ifb->temporary_statement(static_cast(idx)); if (temp == NULL) { if (!ifb->saw_error()) go_error_at(loc, ("invalid export data for %qs: " "undefined temporary reference index at %lu"), ifb->name().c_str(), static_cast(ifb->off())); ifb->set_saw_error(); return Expression::make_error(loc); } return Expression::make_temporary_reference(temp, loc); } // Get a backend expression referring to the variable. Bexpression* Temporary_reference_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Bvariable* bvar = this->statement_->get_backend_variable(context); Bexpression* ret = gogo->backend()->var_expression(bvar, this->location()); // The backend can't always represent the same set of recursive types // that the Go frontend can. In some cases this means that a // temporary variable won't have the right backend type. Correct // that here by adding a type cast. We need to use base() to push // the circularity down one level. Type* stype = this->statement_->type(); if (!this->is_lvalue_ && stype->points_to() != NULL && stype->points_to()->is_void_type()) { Btype* btype = this->type()->base()->get_backend(gogo); ret = gogo->backend()->convert_expression(btype, ret, this->location()); } return ret; } // Ast dump for temporary reference. void Temporary_reference_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_temp_variable_name(this->statement_); } // Make a reference to a temporary variable. Temporary_reference_expression* Expression::make_temporary_reference(Temporary_statement* statement, Location location) { statement->add_use(); return new Temporary_reference_expression(statement, location); } // Class Set_and_use_temporary_expression. // Return the type. Type* Set_and_use_temporary_expression::do_type() { return this->statement_->type(); } // Determine the type of the expression. void Set_and_use_temporary_expression::do_determine_type( const Type_context* context) { this->expr_->determine_type(context); } // Take the address. void Set_and_use_temporary_expression::do_address_taken(bool) { this->statement_->set_is_address_taken(); } // Return the backend representation. Bexpression* Set_and_use_temporary_expression::do_get_backend(Translate_context* context) { Location loc = this->location(); Gogo* gogo = context->gogo(); Bvariable* bvar = this->statement_->get_backend_variable(context); Bexpression* lvar_ref = gogo->backend()->var_expression(bvar, loc); Named_object* fn = context->function(); go_assert(fn != NULL); Bfunction* bfn = fn->func_value()->get_or_make_decl(gogo, fn); Bexpression* bexpr = this->expr_->get_backend(context); Bstatement* set = gogo->backend()->assignment_statement(bfn, lvar_ref, bexpr, loc); Bexpression* var_ref = gogo->backend()->var_expression(bvar, loc); Bexpression* ret = gogo->backend()->compound_expression(set, var_ref, loc); return ret; } // Dump. void Set_and_use_temporary_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << '('; ast_dump_context->dump_temp_variable_name(this->statement_); ast_dump_context->ostream() << " = "; this->expr_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ')'; } // Make a set-and-use temporary. Set_and_use_temporary_expression* Expression::make_set_and_use_temporary(Temporary_statement* statement, Expression* expr, Location location) { return new Set_and_use_temporary_expression(statement, expr, location); } // A sink expression--a use of the blank identifier _. class Sink_expression : public Expression { public: Sink_expression(Location location) : Expression(EXPRESSION_SINK, location), type_(NULL), bvar_(NULL) { } protected: bool do_discarding_value() { return true; } Type* do_type(); void do_determine_type(const Type_context*); Expression* do_copy() { return new Sink_expression(this->location()); } Bexpression* do_get_backend(Translate_context*); void do_dump_expression(Ast_dump_context*) const; private: // The type of this sink variable. Type* type_; // The temporary variable we generate. Bvariable* bvar_; }; // Return the type of a sink expression. Type* Sink_expression::do_type() { if (this->type_ == NULL) return Type::make_sink_type(); return this->type_; } // Determine the type of a sink expression. void Sink_expression::do_determine_type(const Type_context* context) { if (context->type != NULL) this->type_ = context->type; } // Return a temporary variable for a sink expression. This will // presumably be a write-only variable which the middle-end will drop. Bexpression* Sink_expression::do_get_backend(Translate_context* context) { Location loc = this->location(); Gogo* gogo = context->gogo(); if (this->bvar_ == NULL) { if (this->type_ == NULL || this->type_->is_sink_type()) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } Named_object* fn = context->function(); go_assert(fn != NULL); Bfunction* fn_ctx = fn->func_value()->get_or_make_decl(gogo, fn); Btype* bt = this->type_->get_backend(context->gogo()); Bstatement* decl; this->bvar_ = gogo->backend()->temporary_variable(fn_ctx, context->bblock(), bt, NULL, 0, loc, &decl); Bexpression* var_ref = gogo->backend()->var_expression(this->bvar_, loc); var_ref = gogo->backend()->compound_expression(decl, var_ref, loc); return var_ref; } return gogo->backend()->var_expression(this->bvar_, loc); } // Ast dump for sink expression. void Sink_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "_" ; } // Make a sink expression. Expression* Expression::make_sink(Location location) { return new Sink_expression(location); } // Class Func_expression. // FIXME: Can a function expression appear in a constant expression? // The value is unchanging. Initializing a constant to the address of // a function seems like it could work, though there might be little // point to it. // Traversal. int Func_expression::do_traverse(Traverse* traverse) { return (this->closure_ == NULL ? TRAVERSE_CONTINUE : Expression::traverse(&this->closure_, traverse)); } // Return the type of a function expression. Type* Func_expression::do_type() { if (this->function_->is_function()) return this->function_->func_value()->type(); else if (this->function_->is_function_declaration()) return this->function_->func_declaration_value()->type(); else go_unreachable(); } // Get the backend representation for the code of a function expression. Bexpression* Func_expression::get_code_pointer(Gogo* gogo, Named_object* no, Location loc) { Function_type* fntype; if (no->is_function()) fntype = no->func_value()->type(); else if (no->is_function_declaration()) fntype = no->func_declaration_value()->type(); else go_unreachable(); // Builtin functions are handled specially by Call_expression. We // can't take their address. if (fntype->is_builtin()) { go_error_at(loc, ("invalid use of special built-in function %qs; " "must be called"), no->message_name().c_str()); return gogo->backend()->error_expression(); } Bfunction* fndecl; if (no->is_function()) fndecl = no->func_value()->get_or_make_decl(gogo, no); else if (no->is_function_declaration()) fndecl = no->func_declaration_value()->get_or_make_decl(gogo, no); else go_unreachable(); return gogo->backend()->function_code_expression(fndecl, loc); } // Get the backend representation for a function expression. This is used when // we take the address of a function rather than simply calling it. A func // value is represented as a pointer to a block of memory. The first // word of that memory is a pointer to the function code. The // remaining parts of that memory are the addresses of variables that // the function closes over. Bexpression* Func_expression::do_get_backend(Translate_context* context) { // If there is no closure, just use the function descriptor. if (this->closure_ == NULL) { Gogo* gogo = context->gogo(); Named_object* no = this->function_; Expression* descriptor; if (no->is_function()) descriptor = no->func_value()->descriptor(gogo, no); else if (no->is_function_declaration()) { if (no->func_declaration_value()->type()->is_builtin()) { go_error_at(this->location(), ("invalid use of special built-in function %qs; " "must be called"), no->message_name().c_str()); return gogo->backend()->error_expression(); } descriptor = no->func_declaration_value()->descriptor(gogo, no); } else go_unreachable(); Bexpression* bdesc = descriptor->get_backend(context); return gogo->backend()->address_expression(bdesc, this->location()); } go_assert(this->function_->func_value()->enclosing() != NULL); // If there is a closure, then the closure is itself the function // expression. It is a pointer to a struct whose first field points // to the function code and whose remaining fields are the addresses // of the closed-over variables. Bexpression *bexpr = this->closure_->get_backend(context); // Introduce a backend type conversion, to account for any differences // between the argument type (function descriptor, struct with a // single field) and the closure (struct with multiple fields). Gogo* gogo = context->gogo(); Btype *btype = this->type()->get_backend(gogo); return gogo->backend()->convert_expression(btype, bexpr, this->location()); } // The cost of inlining a function reference. int Func_expression::do_inlining_cost() const { // FIXME: We don't inline references to nested functions. if (this->closure_ != NULL) return 0x100000; if (this->function_->is_function() && this->function_->func_value()->enclosing() != NULL) return 0x100000; return 1; } // Export a reference to a function. void Func_expression::do_export(Export_function_body* efb) const { Expression::export_name(efb, this->function_); } // Ast dump for function. void Func_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << this->function_->name(); if (this->closure_ != NULL) { ast_dump_context->ostream() << " {closure = "; this->closure_->dump_expression(ast_dump_context); ast_dump_context->ostream() << "}"; } } // Make a reference to a function in an expression. Expression* Expression::make_func_reference(Named_object* function, Expression* closure, Location location) { Func_expression* fe = new Func_expression(function, closure, location); // Detect references to builtin functions and set the runtime code if // appropriate. if (function->is_function_declaration()) fe->set_runtime_code(Runtime::name_to_code(function->name())); return fe; } // Class Func_descriptor_expression. // Constructor. Func_descriptor_expression::Func_descriptor_expression(Named_object* fn) : Expression(EXPRESSION_FUNC_DESCRIPTOR, fn->location()), fn_(fn), dvar_(NULL) { go_assert(!fn->is_function() || !fn->func_value()->needs_closure()); } // Traversal. int Func_descriptor_expression::do_traverse(Traverse*) { return TRAVERSE_CONTINUE; } // All function descriptors have the same type. Type* Func_descriptor_expression::descriptor_type; void Func_descriptor_expression::make_func_descriptor_type() { if (Func_descriptor_expression::descriptor_type != NULL) return; Type* uintptr_type = Type::lookup_integer_type("uintptr"); Type* struct_type = Type::make_builtin_struct_type(1, "fn", uintptr_type); Func_descriptor_expression::descriptor_type = Type::make_builtin_named_type("functionDescriptor", struct_type); } Type* Func_descriptor_expression::do_type() { Func_descriptor_expression::make_func_descriptor_type(); return Func_descriptor_expression::descriptor_type; } // The backend representation for a function descriptor. Bexpression* Func_descriptor_expression::do_get_backend(Translate_context* context) { Named_object* no = this->fn_; Location loc = no->location(); if (this->dvar_ != NULL) return context->backend()->var_expression(this->dvar_, loc); Gogo* gogo = context->gogo(); Backend_name bname; gogo->function_descriptor_backend_name(no, &bname); bool is_descriptor = false; if (no->is_function_declaration() && !no->func_declaration_value()->asm_name().empty() && Linemap::is_predeclared_location(no->location())) is_descriptor = true; // The runtime package implements some functions defined in the // syscall package. Let the syscall package define the descriptor // in this case. if (gogo->compiling_runtime() && gogo->package_name() == "runtime" && no->is_function() && !no->func_value()->asm_name().empty() && no->func_value()->asm_name().compare(0, 8, "syscall.") == 0) is_descriptor = true; Btype* btype = this->type()->get_backend(gogo); Bvariable* bvar; if (no->package() != NULL || is_descriptor) bvar = context->backend()->immutable_struct_reference(bname.name(), bname.optional_asm_name(), btype, loc); else { Location bloc = Linemap::predeclared_location(); // The runtime package has hash/equality functions that are // referenced by type descriptors outside of the runtime, so the // function descriptors must be visible even though they are not // exported. bool is_exported_runtime = false; if (gogo->compiling_runtime() && gogo->package_name() == "runtime" && (no->name().find("hash") != std::string::npos || no->name().find("equal") != std::string::npos)) is_exported_runtime = true; bool is_hidden = ((no->is_function() && no->func_value()->enclosing() != NULL) || (Gogo::is_hidden_name(no->name()) && !is_exported_runtime) || Gogo::is_thunk(no)); if (no->is_function() && no->func_value()->is_referenced_by_inline()) is_hidden = false; unsigned int flags = 0; if (is_hidden) flags |= Backend::variable_is_hidden; bvar = context->backend()->immutable_struct(bname.name(), bname.optional_asm_name(), flags, btype, bloc); Expression_list* vals = new Expression_list(); vals->push_back(Expression::make_func_code_reference(this->fn_, bloc)); Expression* init = Expression::make_struct_composite_literal(this->type(), vals, bloc); Translate_context bcontext(gogo, NULL, NULL, NULL); bcontext.set_is_const(); Bexpression* binit = init->get_backend(&bcontext); context->backend()->immutable_struct_set_init(bvar, bname.name(), flags, btype, bloc, binit); } this->dvar_ = bvar; return gogo->backend()->var_expression(bvar, loc); } // Print a function descriptor expression. void Func_descriptor_expression::do_dump_expression(Ast_dump_context* context) const { context->ostream() << "[descriptor " << this->fn_->name() << "]"; } // Make a function descriptor expression. Func_descriptor_expression* Expression::make_func_descriptor(Named_object* fn) { return new Func_descriptor_expression(fn); } // Make the function descriptor type, so that it can be converted. void Expression::make_func_descriptor_type() { Func_descriptor_expression::make_func_descriptor_type(); } // A reference to just the code of a function. class Func_code_reference_expression : public Expression { public: Func_code_reference_expression(Named_object* function, Location location) : Expression(EXPRESSION_FUNC_CODE_REFERENCE, location), function_(function) { } protected: int do_traverse(Traverse*) { return TRAVERSE_CONTINUE; } bool do_is_static_initializer() const { return true; } Type* do_type() { return Type::make_pointer_type(Type::make_void_type()); } void do_determine_type(const Type_context*) { } Expression* do_copy() { return Expression::make_func_code_reference(this->function_, this->location()); } Bexpression* do_get_backend(Translate_context*); void do_dump_expression(Ast_dump_context* context) const { context->ostream() << "[raw " << this->function_->name() << "]" ; } private: // The function. Named_object* function_; }; // Get the backend representation for a reference to function code. Bexpression* Func_code_reference_expression::do_get_backend(Translate_context* context) { return Func_expression::get_code_pointer(context->gogo(), this->function_, this->location()); } // Make a reference to the code of a function. Expression* Expression::make_func_code_reference(Named_object* function, Location location) { return new Func_code_reference_expression(function, location); } // Class Unknown_expression. // Return the name of an unknown expression. const std::string& Unknown_expression::name() const { return this->named_object_->name(); } // Lower a reference to an unknown name. Expression* Unknown_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int) { Location location = this->location(); Named_object* no = this->named_object_; Named_object* real; if (!no->is_unknown()) real = no; else { real = no->unknown_value()->real_named_object(); if (real == NULL) { if (!this->no_error_message_) go_error_at(location, "reference to undefined name %qs", this->named_object_->message_name().c_str()); return Expression::make_error(location); } } switch (real->classification()) { case Named_object::NAMED_OBJECT_CONST: return Expression::make_const_reference(real, location); case Named_object::NAMED_OBJECT_TYPE: return Expression::make_type(real->type_value(), location); case Named_object::NAMED_OBJECT_TYPE_DECLARATION: if (!this->no_error_message_) go_error_at(location, "reference to undefined type %qs", real->message_name().c_str()); return Expression::make_error(location); case Named_object::NAMED_OBJECT_VAR: real->var_value()->set_is_used(); return Expression::make_var_reference(real, location); case Named_object::NAMED_OBJECT_FUNC: case Named_object::NAMED_OBJECT_FUNC_DECLARATION: return Expression::make_func_reference(real, NULL, location); case Named_object::NAMED_OBJECT_PACKAGE: if (!this->no_error_message_) go_error_at(location, "unexpected reference to package"); return Expression::make_error(location); default: go_unreachable(); } } // Dump the ast representation for an unknown expression to a dump context. void Unknown_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "_Unknown_(" << this->named_object_->name() << ")"; } // Make a reference to an unknown name. Unknown_expression* Expression::make_unknown_reference(Named_object* no, Location location) { return new Unknown_expression(no, location); } // Start exporting a type conversion for a constant, if needed. This // returns whether we need to export a closing parenthesis. bool Expression::export_constant_type(Export_function_body* efb, Type* type) { if (type == NULL || type->is_abstract() || type == efb->type_context()) return false; efb->write_c_string("$convert("); efb->write_type(type); efb->write_c_string(", "); return true; } // Finish a type conversion for a constant. void Expression::finish_export_constant_type(Export_function_body* efb, bool needed) { if (needed) efb->write_c_string(")"); } // A boolean expression. class Boolean_expression : public Expression { public: Boolean_expression(bool val, Location location) : Expression(EXPRESSION_BOOLEAN, location), val_(val), type_(NULL) { } static Expression* do_import(Import_expression*, Location); protected: int do_traverse(Traverse*); bool do_is_constant() const { return true; } bool do_is_zero_value() const { return this->val_ == false; } bool do_boolean_constant_value(bool* val) const { *val = this->val_; return true; } bool do_is_static_initializer() const { return true; } Type* do_type(); void do_determine_type(const Type_context*); Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context* context) { return context->backend()->boolean_constant_expression(this->val_); } int do_inlining_cost() const { return 1; } void do_export(Export_function_body* efb) const; void do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << (this->val_ ? "true" : "false"); } private: // The constant. bool val_; // The type as determined by context. Type* type_; }; // Traverse a boolean expression. We just need to traverse the type // if there is one. int Boolean_expression::do_traverse(Traverse* traverse) { if (this->type_ != NULL) return Type::traverse(this->type_, traverse); return TRAVERSE_CONTINUE; } // Get the type. Type* Boolean_expression::do_type() { if (this->type_ == NULL) this->type_ = Type::make_boolean_type(); return this->type_; } // Set the type from the context. void Boolean_expression::do_determine_type(const Type_context* context) { if (this->type_ != NULL && !this->type_->is_abstract()) ; else if (context->type != NULL && context->type->is_boolean_type()) this->type_ = context->type; else if (!context->may_be_abstract) this->type_ = Type::lookup_bool_type(); } // Export a boolean constant. void Boolean_expression::do_export(Export_function_body* efb) const { bool exported_type = Expression::export_constant_type(efb, this->type_); efb->write_c_string(this->val_ ? "$true" : "$false"); Expression::finish_export_constant_type(efb, exported_type); } // Import a boolean constant. Expression* Boolean_expression::do_import(Import_expression* imp, Location loc) { if (imp->version() >= EXPORT_FORMAT_V3) imp->require_c_string("$"); if (imp->peek_char() == 't') { imp->require_c_string("true"); return Expression::make_boolean(true, loc); } else { imp->require_c_string("false"); return Expression::make_boolean(false, loc); } } // Make a boolean expression. Expression* Expression::make_boolean(bool val, Location location) { return new Boolean_expression(val, location); } // Class String_expression. // Traverse a string expression. We just need to traverse the type // if there is one. int String_expression::do_traverse(Traverse* traverse) { if (this->type_ != NULL) return Type::traverse(this->type_, traverse); return TRAVERSE_CONTINUE; } // Get the type. Type* String_expression::do_type() { if (this->type_ == NULL) this->type_ = Type::make_string_type(); return this->type_; } // Set the type from the context. void String_expression::do_determine_type(const Type_context* context) { if (this->type_ != NULL && !this->type_->is_abstract()) ; else if (context->type != NULL && context->type->is_string_type()) this->type_ = context->type; else if (!context->may_be_abstract) this->type_ = Type::lookup_string_type(); } // Build a string constant. Bexpression* String_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Btype* btype = Type::make_string_type()->get_backend(gogo); Location loc = this->location(); std::vector init(2); if (this->val_.size() == 0) init[0] = gogo->backend()->nil_pointer_expression(); else { Bexpression* str_cst = gogo->backend()->string_constant_expression(this->val_); init[0] = gogo->backend()->address_expression(str_cst, loc); } Btype* int_btype = Type::lookup_integer_type("int")->get_backend(gogo); mpz_t lenval; mpz_init_set_ui(lenval, this->val_.length()); init[1] = gogo->backend()->integer_constant_expression(int_btype, lenval); mpz_clear(lenval); return gogo->backend()->constructor_expression(btype, init, loc); } // Write string literal to string dump. void String_expression::export_string(String_dump* exp, const String_expression* str) { std::string s; s.reserve(str->val_.length() * 4 + 2); s += '"'; for (std::string::const_iterator p = str->val_.begin(); p != str->val_.end(); ++p) { if (*p == '\\' || *p == '"') { s += '\\'; s += *p; } else if (*p >= 0x20 && *p < 0x7f) s += *p; else if (*p == '\n') s += "\\n"; else if (*p == '\t') s += "\\t"; else { s += "\\x"; unsigned char c = *p; unsigned int dig = c >> 4; s += dig < 10 ? '0' + dig : 'A' + dig - 10; dig = c & 0xf; s += dig < 10 ? '0' + dig : 'A' + dig - 10; } } s += '"'; exp->write_string(s); } // Export a string expression. void String_expression::do_export(Export_function_body* efb) const { bool exported_type = Expression::export_constant_type(efb, this->type_); String_expression::export_string(efb, this); Expression::finish_export_constant_type(efb, exported_type); } // Import a string expression. Expression* String_expression::do_import(Import_expression* imp, Location loc) { imp->require_c_string("\""); std::string val; while (true) { int c = imp->get_char(); if (c == '"' || c == -1) break; if (c != '\\') val += static_cast(c); else { c = imp->get_char(); if (c == '\\' || c == '"') val += static_cast(c); else if (c == 'n') val += '\n'; else if (c == 't') val += '\t'; else if (c == 'x') { c = imp->get_char(); unsigned int vh = c >= '0' && c <= '9' ? c - '0' : c - 'A' + 10; c = imp->get_char(); unsigned int vl = c >= '0' && c <= '9' ? c - '0' : c - 'A' + 10; char v = (vh << 4) | vl; val += v; } else { go_error_at(imp->location(), "bad string constant"); return Expression::make_error(loc); } } } return Expression::make_string(val, loc); } // Ast dump for string expression. void String_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { String_expression::export_string(ast_dump_context, this); } // Make a string expression with abstract string type (common case). Expression* Expression::make_string(const std::string& val, Location location) { return new String_expression(val, NULL, location); } // Make a string expression with a specific string type. Expression* Expression::make_string_typed(const std::string& val, Type* type, Location location) { return new String_expression(val, type, location); } // An expression that evaluates to some characteristic of a string. // This is used when indexing, bound-checking, or nil checking a string. class String_info_expression : public Expression { public: String_info_expression(Expression* string, String_info string_info, Location location) : Expression(EXPRESSION_STRING_INFO, location), string_(string), string_info_(string_info) { } protected: Type* do_type(); void do_determine_type(const Type_context*) { go_unreachable(); } Expression* do_copy() { return new String_info_expression(this->string_->copy(), this->string_info_, this->location()); } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; void do_issue_nil_check() { this->string_->issue_nil_check(); } private: // The string for which we are getting information. Expression* string_; // What information we want. String_info string_info_; }; // Return the type of the string info. Type* String_info_expression::do_type() { switch (this->string_info_) { case STRING_INFO_DATA: { Type* byte_type = Type::lookup_integer_type("uint8"); return Type::make_pointer_type(byte_type); } case STRING_INFO_LENGTH: return Type::lookup_integer_type("int"); default: go_unreachable(); } } // Return string information in GENERIC. Bexpression* String_info_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Bexpression* bstring = this->string_->get_backend(context); switch (this->string_info_) { case STRING_INFO_DATA: case STRING_INFO_LENGTH: return gogo->backend()->struct_field_expression(bstring, this->string_info_, this->location()); break; default: go_unreachable(); } } // Dump ast representation for a type info expression. void String_info_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "stringinfo("; this->string_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ","; ast_dump_context->ostream() << (this->string_info_ == STRING_INFO_DATA ? "data" : this->string_info_ == STRING_INFO_LENGTH ? "length" : "unknown"); ast_dump_context->ostream() << ")"; } // Make a string info expression. Expression* Expression::make_string_info(Expression* string, String_info string_info, Location location) { return new String_info_expression(string, string_info, location); } // An expression that represents an string value: a struct with value pointer // and length fields. class String_value_expression : public Expression { public: String_value_expression(Expression* valptr, Expression* len, Location location) : Expression(EXPRESSION_STRING_VALUE, location), valptr_(valptr), len_(len) { } protected: int do_traverse(Traverse*); Type* do_type() { return Type::make_string_type(); } void do_determine_type(const Type_context*) { go_unreachable(); } Expression* do_copy() { return new String_value_expression(this->valptr_->copy(), this->len_->copy(), this->location()); } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; private: // The value pointer. Expression* valptr_; // The length. Expression* len_; }; int String_value_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->valptr_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->len_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } Bexpression* String_value_expression::do_get_backend(Translate_context* context) { std::vector vals(2); vals[0] = this->valptr_->get_backend(context); vals[1] = this->len_->get_backend(context); Gogo* gogo = context->gogo(); Btype* btype = Type::make_string_type()->get_backend(gogo); return gogo->backend()->constructor_expression(btype, vals, this->location()); } void String_value_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "stringvalue("; ast_dump_context->ostream() << "value: "; this->valptr_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ", length: "; this->len_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ")"; } Expression* Expression::make_string_value(Expression* valptr, Expression* len, Location location) { return new String_value_expression(valptr, len, location); } // Make an integer expression. class Integer_expression : public Expression { public: Integer_expression(const mpz_t* val, Type* type, bool is_character_constant, Location location) : Expression(EXPRESSION_INTEGER, location), type_(type), is_character_constant_(is_character_constant) { mpz_init_set(this->val_, *val); } static Expression* do_import(Import_expression*, Location); // Write VAL to string dump. static void export_integer(String_dump* exp, const mpz_t val); // Write VAL to dump context. static void dump_integer(Ast_dump_context* ast_dump_context, const mpz_t val); protected: int do_traverse(Traverse*); bool do_is_constant() const { return true; } bool do_is_zero_value() const { return mpz_sgn(this->val_) == 0; } bool do_is_static_initializer() const { return true; } bool do_numeric_constant_value(Numeric_constant* nc) const; Type* do_type(); void do_determine_type(const Type_context* context); void do_check_types(Gogo*); Bexpression* do_get_backend(Translate_context*); Expression* do_copy() { if (this->is_character_constant_) return Expression::make_character(&this->val_, (this->type_ == NULL ? NULL : this->type_->copy_expressions()), this->location()); else return Expression::make_integer_z(&this->val_, (this->type_ == NULL ? NULL : this->type_->copy_expressions()), this->location()); } int do_inlining_cost() const { return 1; } void do_export(Export_function_body*) const; void do_dump_expression(Ast_dump_context*) const; private: // The integer value. mpz_t val_; // The type so far. Type* type_; // Whether this is a character constant. bool is_character_constant_; }; // Traverse an integer expression. We just need to traverse the type // if there is one. int Integer_expression::do_traverse(Traverse* traverse) { if (this->type_ != NULL) return Type::traverse(this->type_, traverse); return TRAVERSE_CONTINUE; } // Return a numeric constant for this expression. We have to mark // this as a character when appropriate. bool Integer_expression::do_numeric_constant_value(Numeric_constant* nc) const { if (this->is_character_constant_) nc->set_rune(this->type_, this->val_); else nc->set_int(this->type_, this->val_); return true; } // Return the current type. If we haven't set the type yet, we return // an abstract integer type. Type* Integer_expression::do_type() { if (this->type_ == NULL) { if (this->is_character_constant_) this->type_ = Type::make_abstract_character_type(); else this->type_ = Type::make_abstract_integer_type(); } return this->type_; } // Set the type of the integer value. Here we may switch from an // abstract type to a real type. void Integer_expression::do_determine_type(const Type_context* context) { if (this->type_ != NULL && !this->type_->is_abstract()) ; else if (context->type != NULL && context->type->is_numeric_type()) this->type_ = context->type; else if (!context->may_be_abstract) { if (this->is_character_constant_) this->type_ = Type::lookup_integer_type("int32"); else this->type_ = Type::lookup_integer_type("int"); } } // Check the type of an integer constant. void Integer_expression::do_check_types(Gogo*) { Type* type = this->type_; if (type == NULL) return; Numeric_constant nc; if (this->is_character_constant_) nc.set_rune(NULL, this->val_); else nc.set_int(NULL, this->val_); if (!nc.set_type(type, true, this->location())) this->set_is_error(); } // Get the backend representation for an integer constant. Bexpression* Integer_expression::do_get_backend(Translate_context* context) { if (this->is_error_expression() || (this->type_ != NULL && this->type_->is_error_type())) { go_assert(saw_errors()); return context->gogo()->backend()->error_expression(); } Type* resolved_type = NULL; if (this->type_ != NULL && !this->type_->is_abstract()) resolved_type = this->type_; else if (this->type_ != NULL && this->type_->float_type() != NULL) { // We are converting to an abstract floating point type. resolved_type = Type::lookup_float_type("float64"); } else if (this->type_ != NULL && this->type_->complex_type() != NULL) { // We are converting to an abstract complex type. resolved_type = Type::lookup_complex_type("complex128"); } else { // If we still have an abstract type here, then this is being // used in a constant expression which didn't get reduced for // some reason. Use a type which will fit the value. We use <, // not <=, because we need an extra bit for the sign bit. int bits = mpz_sizeinbase(this->val_, 2); Type* int_type = Type::lookup_integer_type("int"); if (bits < int_type->integer_type()->bits()) resolved_type = int_type; else if (bits < 64) resolved_type = Type::lookup_integer_type("int64"); else { if (!saw_errors()) go_error_at(this->location(), "unknown type for large integer constant"); return context->gogo()->backend()->error_expression(); } } Numeric_constant nc; nc.set_int(resolved_type, this->val_); return Expression::backend_numeric_constant_expression(context, &nc); } // Write VAL to export data. void Integer_expression::export_integer(String_dump* exp, const mpz_t val) { char* s = mpz_get_str(NULL, 10, val); exp->write_c_string(s); free(s); } // Export an integer in a constant expression. void Integer_expression::do_export(Export_function_body* efb) const { bool exported_type = Expression::export_constant_type(efb, this->type_); Integer_expression::export_integer(efb, this->val_); if (this->is_character_constant_) efb->write_c_string("'"); // A trailing space lets us reliably identify the end of the number. efb->write_c_string(" "); Expression::finish_export_constant_type(efb, exported_type); } // Import an integer, floating point, or complex value. This handles // all these types because they all start with digits. Expression* Integer_expression::do_import(Import_expression* imp, Location loc) { std::string num = imp->read_identifier(); imp->require_c_string(" "); if (!num.empty() && num[num.length() - 1] == 'i') { mpfr_t real; size_t plus_pos = num.find('+', 1); size_t minus_pos = num.find('-', 1); size_t pos; if (plus_pos == std::string::npos) pos = minus_pos; else if (minus_pos == std::string::npos) pos = plus_pos; else { go_error_at(imp->location(), "bad number in import data: %qs", num.c_str()); return Expression::make_error(loc); } if (pos == std::string::npos) mpfr_init_set_ui(real, 0, MPFR_RNDN); else { std::string real_str = num.substr(0, pos); if (mpfr_init_set_str(real, real_str.c_str(), 10, MPFR_RNDN) != 0) { go_error_at(imp->location(), "bad number in import data: %qs", real_str.c_str()); return Expression::make_error(loc); } } std::string imag_str; if (pos == std::string::npos) imag_str = num; else imag_str = num.substr(pos); imag_str = imag_str.substr(0, imag_str.size() - 1); mpfr_t imag; if (mpfr_init_set_str(imag, imag_str.c_str(), 10, MPFR_RNDN) != 0) { go_error_at(imp->location(), "bad number in import data: %qs", imag_str.c_str()); return Expression::make_error(loc); } mpc_t cval; mpc_init2(cval, mpc_precision); mpc_set_fr_fr(cval, real, imag, MPC_RNDNN); mpfr_clear(real); mpfr_clear(imag); Expression* ret = Expression::make_complex(&cval, NULL, loc); mpc_clear(cval); return ret; } else if (num.find('.') == std::string::npos && num.find('E') == std::string::npos) { bool is_character_constant = (!num.empty() && num[num.length() - 1] == '\''); if (is_character_constant) num = num.substr(0, num.length() - 1); mpz_t val; if (mpz_init_set_str(val, num.c_str(), 10) != 0) { go_error_at(imp->location(), "bad number in import data: %qs", num.c_str()); return Expression::make_error(loc); } Expression* ret; if (is_character_constant) ret = Expression::make_character(&val, NULL, loc); else ret = Expression::make_integer_z(&val, NULL, loc); mpz_clear(val); return ret; } else { mpfr_t val; if (mpfr_init_set_str(val, num.c_str(), 10, MPFR_RNDN) != 0) { go_error_at(imp->location(), "bad number in import data: %qs", num.c_str()); return Expression::make_error(loc); } Expression* ret = Expression::make_float(&val, NULL, loc); mpfr_clear(val); return ret; } } // Ast dump for integer expression. void Integer_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { if (this->is_character_constant_) ast_dump_context->ostream() << '\''; Integer_expression::export_integer(ast_dump_context, this->val_); if (this->is_character_constant_) ast_dump_context->ostream() << '\''; } // Build a new integer value from a multi-precision integer. Expression* Expression::make_integer_z(const mpz_t* val, Type* type, Location location) { return new Integer_expression(val, type, false, location); } // Build a new integer value from an unsigned long. Expression* Expression::make_integer_ul(unsigned long val, Type *type, Location location) { mpz_t zval; mpz_init_set_ui(zval, val); Expression* ret = Expression::make_integer_z(&zval, type, location); mpz_clear(zval); return ret; } // Build a new integer value from a signed long. Expression* Expression::make_integer_sl(long val, Type *type, Location location) { mpz_t zval; mpz_init_set_si(zval, val); Expression* ret = Expression::make_integer_z(&zval, type, location); mpz_clear(zval); return ret; } // Store an int64_t in an uninitialized mpz_t. static void set_mpz_from_int64(mpz_t* zval, int64_t val) { if (val >= 0) { unsigned long ul = static_cast(val); if (static_cast(ul) == val) { mpz_init_set_ui(*zval, ul); return; } } uint64_t uv; if (val >= 0) uv = static_cast(val); else uv = static_cast(- val); unsigned long ul = uv & 0xffffffffUL; mpz_init_set_ui(*zval, ul); mpz_t hval; mpz_init_set_ui(hval, static_cast(uv >> 32)); mpz_mul_2exp(hval, hval, 32); mpz_add(*zval, *zval, hval); mpz_clear(hval); if (val < 0) mpz_neg(*zval, *zval); } // Build a new integer value from an int64_t. Expression* Expression::make_integer_int64(int64_t val, Type* type, Location location) { mpz_t zval; set_mpz_from_int64(&zval, val); Expression* ret = Expression::make_integer_z(&zval, type, location); mpz_clear(zval); return ret; } // Build a new character constant value. Expression* Expression::make_character(const mpz_t* val, Type* type, Location location) { return new Integer_expression(val, type, true, location); } // Floats. class Float_expression : public Expression { public: Float_expression(const mpfr_t* val, Type* type, Location location) : Expression(EXPRESSION_FLOAT, location), type_(type) { mpfr_init_set(this->val_, *val, MPFR_RNDN); } // Write VAL to export data. static void export_float(String_dump* exp, const mpfr_t val); // Write VAL to dump file. static void dump_float(Ast_dump_context* ast_dump_context, const mpfr_t val); protected: int do_traverse(Traverse*); bool do_is_constant() const { return true; } bool do_is_zero_value() const { return mpfr_zero_p(this->val_) != 0 && mpfr_signbit(this->val_) == 0; } bool do_is_static_initializer() const { return true; } bool do_numeric_constant_value(Numeric_constant* nc) const { nc->set_float(this->type_, this->val_); return true; } Type* do_type(); void do_determine_type(const Type_context*); void do_check_types(Gogo*); Expression* do_copy() { return Expression::make_float(&this->val_, (this->type_ == NULL ? NULL : this->type_->copy_expressions()), this->location()); } Bexpression* do_get_backend(Translate_context*); int do_inlining_cost() const { return 1; } void do_export(Export_function_body*) const; void do_dump_expression(Ast_dump_context*) const; private: // The floating point value. mpfr_t val_; // The type so far. Type* type_; }; // Traverse a float expression. We just need to traverse the type if // there is one. int Float_expression::do_traverse(Traverse* traverse) { if (this->type_ != NULL) return Type::traverse(this->type_, traverse); return TRAVERSE_CONTINUE; } // Return the current type. If we haven't set the type yet, we return // an abstract float type. Type* Float_expression::do_type() { if (this->type_ == NULL) this->type_ = Type::make_abstract_float_type(); return this->type_; } // Set the type of the float value. Here we may switch from an // abstract type to a real type. void Float_expression::do_determine_type(const Type_context* context) { if (this->type_ != NULL && !this->type_->is_abstract()) ; else if (context->type != NULL && (context->type->integer_type() != NULL || context->type->float_type() != NULL || context->type->complex_type() != NULL)) this->type_ = context->type; else if (!context->may_be_abstract) this->type_ = Type::lookup_float_type("float64"); } // Check the type of a float value. void Float_expression::do_check_types(Gogo*) { Type* type = this->type_; if (type == NULL) return; Numeric_constant nc; nc.set_float(NULL, this->val_); if (!nc.set_type(this->type_, true, this->location())) this->set_is_error(); } // Get the backend representation for a float constant. Bexpression* Float_expression::do_get_backend(Translate_context* context) { if (this->is_error_expression() || (this->type_ != NULL && this->type_->is_error_type())) { go_assert(saw_errors()); return context->gogo()->backend()->error_expression(); } Type* resolved_type; if (this->type_ != NULL && !this->type_->is_abstract()) resolved_type = this->type_; else if (this->type_ != NULL && this->type_->integer_type() != NULL) { // We have an abstract integer type. We just hope for the best. resolved_type = Type::lookup_integer_type("int"); } else if (this->type_ != NULL && this->type_->complex_type() != NULL) { // We are converting to an abstract complex type. resolved_type = Type::lookup_complex_type("complex128"); } else { // If we still have an abstract type here, then this is being // used in a constant expression which didn't get reduced. We // just use float64 and hope for the best. resolved_type = Type::lookup_float_type("float64"); } Numeric_constant nc; nc.set_float(resolved_type, this->val_); return Expression::backend_numeric_constant_expression(context, &nc); } // Write a floating point number to a string dump. void Float_expression::export_float(String_dump *exp, const mpfr_t val) { mpfr_exp_t exponent; char* s = mpfr_get_str(NULL, &exponent, 10, 0, val, MPFR_RNDN); if (*s == '-') exp->write_c_string("-"); exp->write_c_string("0."); exp->write_c_string(*s == '-' ? s + 1 : s); mpfr_free_str(s); char buf[30]; snprintf(buf, sizeof buf, "E%ld", exponent); exp->write_c_string(buf); } // Export a floating point number in a constant expression. void Float_expression::do_export(Export_function_body* efb) const { bool exported_type = Expression::export_constant_type(efb, this->type_); Float_expression::export_float(efb, this->val_); // A trailing space lets us reliably identify the end of the number. efb->write_c_string(" "); Expression::finish_export_constant_type(efb, exported_type); } // Dump a floating point number to the dump file. void Float_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { Float_expression::export_float(ast_dump_context, this->val_); } // Make a float expression. Expression* Expression::make_float(const mpfr_t* val, Type* type, Location location) { return new Float_expression(val, type, location); } // Complex numbers. class Complex_expression : public Expression { public: Complex_expression(const mpc_t* val, Type* type, Location location) : Expression(EXPRESSION_COMPLEX, location), type_(type) { mpc_init2(this->val_, mpc_precision); mpc_set(this->val_, *val, MPC_RNDNN); } // Write VAL to string dump. static void export_complex(String_dump* exp, const mpc_t val); // Write REAL/IMAG to dump context. static void dump_complex(Ast_dump_context* ast_dump_context, const mpc_t val); protected: int do_traverse(Traverse*); bool do_is_constant() const { return true; } bool do_is_zero_value() const { return mpfr_zero_p(mpc_realref(this->val_)) != 0 && mpfr_signbit(mpc_realref(this->val_)) == 0 && mpfr_zero_p(mpc_imagref(this->val_)) != 0 && mpfr_signbit(mpc_imagref(this->val_)) == 0; } bool do_is_static_initializer() const { return true; } bool do_numeric_constant_value(Numeric_constant* nc) const { nc->set_complex(this->type_, this->val_); return true; } Type* do_type(); void do_determine_type(const Type_context*); void do_check_types(Gogo*); Expression* do_copy() { return Expression::make_complex(&this->val_, (this->type_ == NULL ? NULL : this->type_->copy_expressions()), this->location()); } Bexpression* do_get_backend(Translate_context*); int do_inlining_cost() const { return 2; } void do_export(Export_function_body*) const; void do_dump_expression(Ast_dump_context*) const; private: // The complex value. mpc_t val_; // The type if known. Type* type_; }; // Traverse a complex expression. We just need to traverse the type // if there is one. int Complex_expression::do_traverse(Traverse* traverse) { if (this->type_ != NULL) return Type::traverse(this->type_, traverse); return TRAVERSE_CONTINUE; } // Return the current type. If we haven't set the type yet, we return // an abstract complex type. Type* Complex_expression::do_type() { if (this->type_ == NULL) this->type_ = Type::make_abstract_complex_type(); return this->type_; } // Set the type of the complex value. Here we may switch from an // abstract type to a real type. void Complex_expression::do_determine_type(const Type_context* context) { if (this->type_ != NULL && !this->type_->is_abstract()) ; else if (context->type != NULL && context->type->is_numeric_type()) this->type_ = context->type; else if (!context->may_be_abstract) this->type_ = Type::lookup_complex_type("complex128"); } // Check the type of a complex value. void Complex_expression::do_check_types(Gogo*) { Type* type = this->type_; if (type == NULL) return; Numeric_constant nc; nc.set_complex(NULL, this->val_); if (!nc.set_type(this->type_, true, this->location())) this->set_is_error(); } // Get the backend representation for a complex constant. Bexpression* Complex_expression::do_get_backend(Translate_context* context) { if (this->is_error_expression() || (this->type_ != NULL && this->type_->is_error_type())) { go_assert(saw_errors()); return context->gogo()->backend()->error_expression(); } Type* resolved_type; if (this->type_ != NULL && !this->type_->is_abstract()) resolved_type = this->type_; else if (this->type_ != NULL && this->type_->integer_type() != NULL) { // We are converting to an abstract integer type. resolved_type = Type::lookup_integer_type("int"); } else if (this->type_ != NULL && this->type_->float_type() != NULL) { // We are converting to an abstract float type. resolved_type = Type::lookup_float_type("float64"); } else { // If we still have an abstract type here, this is being // used in a constant expression which didn't get reduced. We // just use complex128 and hope for the best. resolved_type = Type::lookup_complex_type("complex128"); } Numeric_constant nc; nc.set_complex(resolved_type, this->val_); return Expression::backend_numeric_constant_expression(context, &nc); } // Write REAL/IMAG to export data. void Complex_expression::export_complex(String_dump* exp, const mpc_t val) { if (!mpfr_zero_p(mpc_realref(val))) { Float_expression::export_float(exp, mpc_realref(val)); if (mpfr_sgn(mpc_imagref(val)) >= 0) exp->write_c_string("+"); } Float_expression::export_float(exp, mpc_imagref(val)); exp->write_c_string("i"); } // Export a complex number in a constant expression. void Complex_expression::do_export(Export_function_body* efb) const { bool exported_type = Expression::export_constant_type(efb, this->type_); Complex_expression::export_complex(efb, this->val_); // A trailing space lets us reliably identify the end of the number. efb->write_c_string(" "); Expression::finish_export_constant_type(efb, exported_type); } // Dump a complex expression to the dump file. void Complex_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { Complex_expression::export_complex(ast_dump_context, this->val_); } // Make a complex expression. Expression* Expression::make_complex(const mpc_t* val, Type* type, Location location) { return new Complex_expression(val, type, location); } // Find a named object in an expression. class Find_named_object : public Traverse { public: Find_named_object(Named_object* no) : Traverse(traverse_expressions), no_(no), found_(false) { } // Whether we found the object. bool found() const { return this->found_; } protected: int expression(Expression**); private: // The object we are looking for. Named_object* no_; // Whether we found it. bool found_; }; // Class Const_expression. // Traversal. int Const_expression::do_traverse(Traverse* traverse) { if (this->type_ != NULL) return Type::traverse(this->type_, traverse); return TRAVERSE_CONTINUE; } // Whether this is the zero value. bool Const_expression::do_is_zero_value() const { return this->constant_->const_value()->expr()->is_zero_value(); } // Lower a constant expression. This is where we convert the // predeclared constant iota into an integer value. Expression* Const_expression::do_lower(Gogo* gogo, Named_object*, Statement_inserter*, int iota_value) { if (this->constant_->const_value()->expr()->classification() == EXPRESSION_IOTA) { if (iota_value == -1) { go_error_at(this->location(), "iota is only defined in const declarations"); iota_value = 0; } return Expression::make_integer_ul(iota_value, NULL, this->location()); } // Make sure that the constant itself has been lowered. gogo->lower_constant(this->constant_); return this; } // Return a numeric constant value. bool Const_expression::do_numeric_constant_value(Numeric_constant* nc) const { if (this->seen_) return false; Expression* e = this->constant_->const_value()->expr(); this->seen_ = true; bool r = e->numeric_constant_value(nc); this->seen_ = false; Type* ctype; if (this->type_ != NULL) ctype = this->type_; else ctype = this->constant_->const_value()->type(); if (r && ctype != NULL) { if (!nc->set_type(ctype, false, this->location())) return false; } return r; } bool Const_expression::do_string_constant_value(std::string* val) const { if (this->seen_) return false; Expression* e = this->constant_->const_value()->expr(); this->seen_ = true; bool ok = e->string_constant_value(val); this->seen_ = false; return ok; } bool Const_expression::do_boolean_constant_value(bool* val) const { if (this->seen_) return false; Expression* e = this->constant_->const_value()->expr(); this->seen_ = true; bool ok = e->boolean_constant_value(val); this->seen_ = false; return ok; } // Return the type of the const reference. Type* Const_expression::do_type() { if (this->type_ != NULL) return this->type_; Named_constant* nc = this->constant_->const_value(); if (this->seen_ || nc->lowering()) { if (nc->type() == NULL || !nc->type()->is_error_type()) { Location loc = this->location(); if (!this->seen_) loc = nc->location(); go_error_at(loc, "constant refers to itself"); } this->set_is_error(); this->type_ = Type::make_error_type(); nc->set_type(this->type_); return this->type_; } this->seen_ = true; Type* ret = nc->type(); if (ret != NULL) { this->seen_ = false; return ret; } // During parsing, a named constant may have a NULL type, but we // must not return a NULL type here. ret = nc->expr()->type(); this->seen_ = false; if (ret->is_error_type()) nc->set_type(ret); return ret; } // Set the type of the const reference. void Const_expression::do_determine_type(const Type_context* context) { Type* ctype = this->constant_->const_value()->type(); Type* cetype = (ctype != NULL ? ctype : this->constant_->const_value()->expr()->type()); if (ctype != NULL && !ctype->is_abstract()) ; else if (context->type != NULL && context->type->is_numeric_type() && cetype->is_numeric_type()) this->type_ = context->type; else if (context->type != NULL && context->type->is_string_type() && cetype->is_string_type()) this->type_ = context->type; else if (context->type != NULL && context->type->is_boolean_type() && cetype->is_boolean_type()) this->type_ = context->type; else if (!context->may_be_abstract) { if (cetype->is_abstract()) cetype = cetype->make_non_abstract_type(); this->type_ = cetype; } } // Check for a loop in which the initializer of a constant refers to // the constant itself. void Const_expression::check_for_init_loop() { if (this->type_ != NULL && this->type_->is_error()) return; if (this->seen_) { this->report_error(_("constant refers to itself")); this->type_ = Type::make_error_type(); return; } Expression* init = this->constant_->const_value()->expr(); Find_named_object find_named_object(this->constant_); this->seen_ = true; Expression::traverse(&init, &find_named_object); this->seen_ = false; if (find_named_object.found()) { if (this->type_ == NULL || !this->type_->is_error()) { this->report_error(_("constant refers to itself")); this->type_ = Type::make_error_type(); } return; } } // Check types of a const reference. void Const_expression::do_check_types(Gogo*) { if (this->type_ != NULL && this->type_->is_error()) return; this->check_for_init_loop(); // Check that numeric constant fits in type. if (this->type_ != NULL && this->type_->is_numeric_type()) { Numeric_constant nc; if (this->constant_->const_value()->expr()->numeric_constant_value(&nc)) { if (!nc.set_type(this->type_, true, this->location())) this->set_is_error(); } } } // Return the backend representation for a const reference. Bexpression* Const_expression::do_get_backend(Translate_context* context) { if (this->is_error_expression() || (this->type_ != NULL && this->type_->is_error())) { go_assert(saw_errors()); return context->backend()->error_expression(); } // If the type has been set for this expression, but the underlying // object is an abstract int or float, we try to get the abstract // value. Otherwise we may lose something in the conversion. Expression* expr = this->constant_->const_value()->expr(); if (this->type_ != NULL && this->type_->is_numeric_type() && (this->constant_->const_value()->type() == NULL || this->constant_->const_value()->type()->is_abstract())) { Numeric_constant nc; if (expr->numeric_constant_value(&nc) && nc.set_type(this->type_, false, this->location())) { Expression* e = nc.expression(this->location()); return e->get_backend(context); } } if (this->type_ != NULL) expr = Expression::make_cast(this->type_, expr, this->location()); return expr->get_backend(context); } // When exporting a reference to a const as part of a const // expression, we export the value. We ignore the fact that it has // a name. void Const_expression::do_export(Export_function_body* efb) const { this->constant_->const_value()->expr()->export_expression(efb); } // Dump ast representation for constant expression. void Const_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << this->constant_->name(); } // Make a reference to a constant in an expression. Expression* Expression::make_const_reference(Named_object* constant, Location location) { return new Const_expression(constant, location); } // Find a named object in an expression. int Find_named_object::expression(Expression** pexpr) { switch ((*pexpr)->classification()) { case Expression::EXPRESSION_CONST_REFERENCE: { Const_expression* ce = static_cast(*pexpr); if (ce->named_object() == this->no_) break; // We need to check a constant initializer explicitly, as // loops here will not be caught by the loop checking for // variable initializers. ce->check_for_init_loop(); return TRAVERSE_CONTINUE; } case Expression::EXPRESSION_VAR_REFERENCE: if ((*pexpr)->var_expression()->named_object() == this->no_) break; return TRAVERSE_CONTINUE; case Expression::EXPRESSION_FUNC_REFERENCE: if ((*pexpr)->func_expression()->named_object() == this->no_) break; return TRAVERSE_CONTINUE; default: return TRAVERSE_CONTINUE; } this->found_ = true; return TRAVERSE_EXIT; } // The nil value. class Nil_expression : public Expression { public: Nil_expression(Location location) : Expression(EXPRESSION_NIL, location) { } static Expression* do_import(Import_expression*, Location); protected: bool do_is_constant() const { return true; } bool do_is_zero_value() const { return true; } bool do_is_static_initializer() const { return true; } Type* do_type() { return Type::make_nil_type(); } void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context* context) { return context->backend()->nil_pointer_expression(); } int do_inlining_cost() const { return 1; } void do_export(Export_function_body* efb) const { efb->write_c_string("$nil"); } void do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "nil"; } }; // Import a nil expression. Expression* Nil_expression::do_import(Import_expression* imp, Location loc) { if (imp->version() >= EXPORT_FORMAT_V3) imp->require_c_string("$"); imp->require_c_string("nil"); return Expression::make_nil(loc); } // Make a nil expression. Expression* Expression::make_nil(Location location) { return new Nil_expression(location); } // The value of the predeclared constant iota. This is little more // than a marker. This will be lowered to an integer in // Const_expression::do_lower, which is where we know the value that // it should have. class Iota_expression : public Parser_expression { public: Iota_expression(Location location) : Parser_expression(EXPRESSION_IOTA, location) { } protected: Expression* do_lower(Gogo*, Named_object*, Statement_inserter*, int) { go_unreachable(); } // There should only ever be one of these. Expression* do_copy() { go_unreachable(); } void do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "iota"; } }; // Make an iota expression. This is only called for one case: the // value of the predeclared constant iota. Expression* Expression::make_iota() { static Iota_expression iota_expression(Linemap::unknown_location()); return &iota_expression; } // Class Type_conversion_expression. // Traversal. int Type_conversion_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Convert to a constant at lowering time. Also lower conversions // from slice to pointer-to-array, as they can panic. Expression* Type_conversion_expression::do_lower(Gogo*, Named_object*, Statement_inserter* inserter, int) { Type* type = this->type_; Expression* val = this->expr_; Location location = this->location(); if (type->is_numeric_type()) { Numeric_constant nc; if (val->numeric_constant_value(&nc)) { if (!nc.set_type(type, true, location)) return Expression::make_error(location); return nc.expression(location); } } // According to the language specification on string conversions // (http://golang.org/ref/spec#Conversions_to_and_from_a_string_type): // When converting an integer into a string, the string will be a UTF-8 // representation of the integer and integers "outside the range of valid // Unicode code points are converted to '\uFFFD'." if (type->is_string_type()) { Numeric_constant nc; if (val->numeric_constant_value(&nc) && nc.is_int()) { // An integer value doesn't fit in the Unicode code point range if it // overflows the Go "int" type or is negative. unsigned long ul; if (!nc.set_type(Type::lookup_integer_type("int"), false, location) || nc.to_unsigned_long(&ul) == Numeric_constant::NC_UL_NEGATIVE) return Expression::make_string("\ufffd", location); } } if (type->is_slice_type()) { Type* element_type = type->array_type()->element_type()->forwarded(); bool is_byte = (element_type->integer_type() != NULL && element_type->integer_type()->is_byte()); bool is_rune = (element_type->integer_type() != NULL && element_type->integer_type()->is_rune()); if (is_byte || is_rune) { std::string s; if (val->string_constant_value(&s)) { Expression_list* vals = new Expression_list(); if (is_byte) { for (std::string::const_iterator p = s.begin(); p != s.end(); p++) { unsigned char c = static_cast(*p); vals->push_back(Expression::make_integer_ul(c, element_type, location)); } } else { const char *p = s.data(); const char *pend = s.data() + s.length(); while (p < pend) { unsigned int c; int adv = Lex::fetch_char(p, &c); if (adv == 0) { go_warning_at(this->location(), 0, "invalid UTF-8 encoding"); adv = 1; } p += adv; vals->push_back(Expression::make_integer_ul(c, element_type, location)); } } return Expression::make_slice_composite_literal(type, vals, location); } } } if (type->points_to() != NULL && type->points_to()->array_type() != NULL && !type->points_to()->is_slice_type() && val->type()->is_slice_type() && Type::are_identical(type->points_to()->array_type()->element_type(), val->type()->array_type()->element_type(), 0, NULL)) { Temporary_statement* val_temp = NULL; if (!val->is_multi_eval_safe()) { val_temp = Statement::make_temporary(val->type(), NULL, location); inserter->insert(val_temp); val = Expression::make_set_and_use_temporary(val_temp, val, location); } Type* int_type = Type::lookup_integer_type("int"); Temporary_statement* vallen_temp = Statement::make_temporary(int_type, NULL, location); inserter->insert(vallen_temp); Expression* arrlen = type->points_to()->array_type()->length(); Expression* vallen = Expression::make_slice_info(val, Expression::SLICE_INFO_LENGTH, location); vallen = Expression::make_set_and_use_temporary(vallen_temp, vallen, location); Expression* cond = Expression::make_binary(OPERATOR_GT, arrlen, vallen, location); vallen = Expression::make_temporary_reference(vallen_temp, location); Expression* panic = Runtime::make_call(Runtime::PANIC_SLICE_CONVERT, location, 2, arrlen, vallen); Expression* nil = Expression::make_nil(location); Expression* check = Expression::make_conditional(cond, panic, nil, location); if (val_temp == NULL) val = val->copy(); else val = Expression::make_temporary_reference(val_temp, location); Expression* ptr = Expression::make_slice_info(val, Expression::SLICE_INFO_VALUE_POINTER, location); ptr = Expression::make_unsafe_cast(type, ptr, location); return Expression::make_compound(check, ptr, location); } return this; } // Flatten a type conversion by using a temporary variable for the slice // in slice to string conversions. Expression* Type_conversion_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { if (this->type()->is_error_type() || this->expr_->is_error_expression()) { go_assert(saw_errors()); return Expression::make_error(this->location()); } if (((this->type()->is_string_type() && this->expr_->type()->is_slice_type()) || this->expr_->type()->interface_type() != NULL) && !this->expr_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->expr_, this->location()); inserter->insert(temp); this->expr_ = Expression::make_temporary_reference(temp, this->location()); } // For interface conversion and string to/from slice conversions, // decide if we can allocate on stack. if (this->type()->interface_type() != NULL || this->type()->is_string_type() || this->expr_->type()->is_string_type()) { Node* n = Node::make_node(this); if ((n->encoding() & ESCAPE_MASK) == Node::ESCAPE_NONE) this->no_escape_ = true; } return this; } // Return whether a type conversion is a constant. bool Type_conversion_expression::do_is_constant() const { if (!this->expr_->is_constant()) return false; // A conversion to a type that may not be used as a constant is not // a constant. For example, []byte(nil). Type* type = this->type_; if (type->integer_type() == NULL && type->float_type() == NULL && type->complex_type() == NULL && !type->is_boolean_type() && !type->is_string_type()) return false; return true; } // Return whether a type conversion is a zero value. bool Type_conversion_expression::do_is_zero_value() const { if (!this->expr_->is_zero_value()) return false; // Some type conversion from zero value is still not zero value. // For example, []byte("") or interface{}(0). // Conservatively, only report true if the RHS is nil. Type* type = this->type_; if (type->integer_type() == NULL && type->float_type() == NULL && type->complex_type() == NULL && !type->is_boolean_type() && !type->is_string_type()) return this->expr_->is_nil_expression(); return true; } // Return whether a type conversion can be used in a constant // initializer. bool Type_conversion_expression::do_is_static_initializer() const { Type* type = this->type_; Type* expr_type = this->expr_->type(); if (type->interface_type() != NULL || expr_type->interface_type() != NULL) return false; if (!this->expr_->is_static_initializer()) return false; if (Type::are_identical(type, expr_type, Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) return true; if (type->is_string_type() && expr_type->is_string_type()) return true; if ((type->is_numeric_type() || type->is_boolean_type() || type->points_to() != NULL) && (expr_type->is_numeric_type() || expr_type->is_boolean_type() || expr_type->points_to() != NULL)) return true; return false; } // Return the constant numeric value if there is one. bool Type_conversion_expression::do_numeric_constant_value( Numeric_constant* nc) const { if (!this->type_->is_numeric_type()) return false; if (!this->expr_->numeric_constant_value(nc)) return false; return nc->set_type(this->type_, false, this->location()); } // Return the constant string value if there is one. bool Type_conversion_expression::do_string_constant_value(std::string* val) const { if (this->type_->is_string_type() && this->expr_->type()->is_string_type()) return this->expr_->string_constant_value(val); if (this->type_->is_string_type() && this->expr_->type()->integer_type() != NULL) { Numeric_constant nc; if (this->expr_->numeric_constant_value(&nc)) { unsigned long ival; if (nc.to_unsigned_long(&ival) == Numeric_constant::NC_UL_VALID) { unsigned int cval = static_cast(ival); if (static_cast(cval) != ival) { go_warning_at(this->location(), 0, "unicode code point 0x%lx out of range", ival); cval = 0xfffd; // Unicode "replacement character." } val->clear(); Lex::append_char(cval, true, val, this->location()); return true; } } } // FIXME: Could handle conversion from const []int here. return false; } // Return the constant boolean value if there is one. bool Type_conversion_expression::do_boolean_constant_value(bool* val) const { if (!this->type_->is_boolean_type()) return false; return this->expr_->boolean_constant_value(val); } // Determine the resulting type of the conversion. void Type_conversion_expression::do_determine_type(const Type_context*) { Type_context subcontext(this->type_, false); this->expr_->determine_type(&subcontext); } // Check that types are convertible. void Type_conversion_expression::do_check_types(Gogo*) { Type* type = this->type_; Type* expr_type = this->expr_->type(); std::string reason; if (type->is_error() || expr_type->is_error()) { this->set_is_error(); return; } if (this->may_convert_function_types_ && type->function_type() != NULL && expr_type->function_type() != NULL) return; if (Type::are_convertible(type, expr_type, &reason)) return; go_error_at(this->location(), "%s", reason.c_str()); this->set_is_error(); } // Copy. Expression* Type_conversion_expression::do_copy() { Expression* ret = new Type_conversion_expression(this->type_->copy_expressions(), this->expr_->copy(), this->location()); ret->conversion_expression()->set_no_copy(this->no_copy_); return ret; } // Get the backend representation for a type conversion. Bexpression* Type_conversion_expression::do_get_backend(Translate_context* context) { Type* type = this->type_; Type* expr_type = this->expr_->type(); Gogo* gogo = context->gogo(); Btype* btype = type->get_backend(gogo); Location loc = this->location(); if (Type::are_identical(type, expr_type, Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) { Bexpression* bexpr = this->expr_->get_backend(context); return gogo->backend()->convert_expression(btype, bexpr, loc); } else if (type->interface_type() != NULL && expr_type->interface_type() == NULL) { Expression* conversion = Expression::convert_type_to_interface(type, this->expr_, this->no_escape_, loc); return conversion->get_backend(context); } else if (type->interface_type() != NULL || expr_type->interface_type() != NULL) { Expression* conversion = Expression::convert_for_assignment(gogo, type, this->expr_, loc); return conversion->get_backend(context); } else if (type->is_string_type() && expr_type->integer_type() != NULL) { mpz_t intval; Numeric_constant nc; if (this->expr_->numeric_constant_value(&nc) && nc.to_int(&intval)) { std::string s; unsigned int x; if (mpz_fits_uint_p(intval)) x = mpz_get_ui(intval); else { char* ms = mpz_get_str(NULL, 16, intval); go_warning_at(loc, 0, "unicode code point 0x%s out of range in string", ms); free(ms); x = 0xfffd; } Lex::append_char(x, true, &s, loc); mpz_clear(intval); Expression* se = Expression::make_string(s, loc); return se->get_backend(context); } Expression* buf; if (this->no_escape_) { Type* byte_type = Type::lookup_integer_type("uint8"); Expression* buflen = Expression::make_integer_ul(4, NULL, loc); Type* array_type = Type::make_array_type(byte_type, buflen); buf = Expression::make_allocation(array_type, loc); buf->allocation_expression()->set_allocate_on_stack(); buf->allocation_expression()->set_no_zero(); } else buf = Expression::make_nil(loc); Expression* i2s_expr = Runtime::make_call(Runtime::INTSTRING, loc, 2, buf, this->expr_); return Expression::make_cast(type, i2s_expr, loc)->get_backend(context); } else if (type->is_string_type() && expr_type->is_slice_type()) { Array_type* a = expr_type->array_type(); Type* e = a->element_type()->forwarded(); go_assert(e->integer_type() != NULL); go_assert(this->expr_->is_multi_eval_safe()); Expression* buf; if (this->no_escape_ && !this->no_copy_) { Type* byte_type = Type::lookup_integer_type("uint8"); Expression* buflen = Expression::make_integer_ul(tmp_string_buf_size, NULL, loc); Type* array_type = Type::make_array_type(byte_type, buflen); buf = Expression::make_allocation(array_type, loc); buf->allocation_expression()->set_allocate_on_stack(); buf->allocation_expression()->set_no_zero(); } else buf = Expression::make_nil(loc); if (e->integer_type()->is_byte()) { Expression* ptr = Expression::make_slice_info(this->expr_, SLICE_INFO_VALUE_POINTER, loc); Expression* len = Expression::make_slice_info(this->expr_, SLICE_INFO_LENGTH, loc); if (this->no_copy_) { if (gogo->debug_optimization()) go_debug(loc, "no copy string([]byte)"); Expression* str = Expression::make_string_value(ptr, len, loc); return str->get_backend(context); } return Runtime::make_call(Runtime::SLICEBYTETOSTRING, loc, 3, buf, ptr, len)->get_backend(context); } else { go_assert(e->integer_type()->is_rune()); return Runtime::make_call(Runtime::SLICERUNETOSTRING, loc, 2, buf, this->expr_)->get_backend(context); } } else if (type->is_slice_type() && expr_type->is_string_type()) { Type* e = type->array_type()->element_type()->forwarded(); go_assert(e->integer_type() != NULL); Runtime::Function code; if (e->integer_type()->is_byte()) code = Runtime::STRINGTOSLICEBYTE; else { go_assert(e->integer_type()->is_rune()); code = Runtime::STRINGTOSLICERUNE; } Expression* buf; if (this->no_escape_) { Expression* buflen = Expression::make_integer_ul(tmp_string_buf_size, NULL, loc); Type* array_type = Type::make_array_type(e, buflen); buf = Expression::make_allocation(array_type, loc); buf->allocation_expression()->set_allocate_on_stack(); buf->allocation_expression()->set_no_zero(); } else buf = Expression::make_nil(loc); Expression* s2a = Runtime::make_call(code, loc, 2, buf, this->expr_); return Expression::make_unsafe_cast(type, s2a, loc)->get_backend(context); } else if (type->is_numeric_type()) { go_assert(Type::are_convertible(type, expr_type, NULL)); Bexpression* bexpr = this->expr_->get_backend(context); return gogo->backend()->convert_expression(btype, bexpr, loc); } else if ((type->is_unsafe_pointer_type() && (expr_type->points_to() != NULL || expr_type->integer_type())) || (expr_type->is_unsafe_pointer_type() && type->points_to() != NULL) || (this->may_convert_function_types_ && type->function_type() != NULL && expr_type->function_type() != NULL)) { Bexpression* bexpr = this->expr_->get_backend(context); return gogo->backend()->convert_expression(btype, bexpr, loc); } else { Expression* conversion = Expression::convert_for_assignment(gogo, type, this->expr_, loc); return conversion->get_backend(context); } } // Cost of inlining a type conversion. int Type_conversion_expression::do_inlining_cost() const { Type* type = this->type_; Type* expr_type = this->expr_->type(); if (type->interface_type() != NULL || expr_type->interface_type() != NULL) return 10; else if (type->is_string_type() && expr_type->integer_type() != NULL) return 10; else if (type->is_string_type() && expr_type->is_slice_type()) return 10; else if (type->is_slice_type() && expr_type->is_string_type()) return 10; else return 1; } // Output a type conversion in a constant expression. void Type_conversion_expression::do_export(Export_function_body* efb) const { efb->write_c_string("$convert("); efb->write_type(this->type_); efb->write_c_string(", "); Type* old_context = efb->type_context(); efb->set_type_context(this->type_); this->expr_->export_expression(efb); efb->set_type_context(old_context); efb->write_c_string(")"); } // Import a type conversion or a struct construction. Expression* Type_conversion_expression::do_import(Import_expression* imp, Location loc) { imp->require_c_string("$convert("); Type* type = imp->read_type(); imp->require_c_string(", "); Expression* val = Expression::import_expression(imp, loc); imp->require_c_string(")"); return Expression::make_cast(type, val, loc); } // Dump ast representation for a type conversion expression. void Type_conversion_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->expr_); ast_dump_context->ostream() << ") "; } // Make a type cast expression. Expression* Expression::make_cast(Type* type, Expression* val, Location location) { if (type->is_error_type() || val->is_error_expression()) return Expression::make_error(location); return new Type_conversion_expression(type, val, location); } // Class Unsafe_type_conversion_expression. // Traversal. int Unsafe_type_conversion_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Return whether an unsafe type conversion can be used as a constant // initializer. bool Unsafe_type_conversion_expression::do_is_static_initializer() const { Type* type = this->type_; Type* expr_type = this->expr_->type(); if (type->interface_type() != NULL || expr_type->interface_type() != NULL) return false; if (!this->expr_->is_static_initializer()) return false; if (Type::are_convertible(type, expr_type, NULL)) return true; if (type->is_string_type() && expr_type->is_string_type()) return true; if ((type->is_numeric_type() || type->is_boolean_type() || type->points_to() != NULL) && (expr_type->is_numeric_type() || expr_type->is_boolean_type() || expr_type->points_to() != NULL)) return true; return false; } // Copy. Expression* Unsafe_type_conversion_expression::do_copy() { return new Unsafe_type_conversion_expression(this->type_->copy_expressions(), this->expr_->copy(), this->location()); } // Convert to backend representation. Bexpression* Unsafe_type_conversion_expression::do_get_backend(Translate_context* context) { // We are only called for a limited number of cases. Type* t = this->type_; Type* et = this->expr_->type(); if (t->is_error_type() || this->expr_->is_error_expression() || et->is_error_type()) { go_assert(saw_errors()); return context->backend()->error_expression(); } if (t->array_type() != NULL) go_assert(et->array_type() != NULL && t->is_slice_type() == et->is_slice_type()); else if (t->struct_type() != NULL) { if (t->named_type() != NULL && et->named_type() != NULL && !Type::are_convertible(t, et, NULL)) { go_assert(saw_errors()); return context->backend()->error_expression(); } go_assert(et->struct_type() != NULL && Type::are_convertible(t, et, NULL)); } else if (t->map_type() != NULL) go_assert(et->map_type() != NULL || et->points_to() != NULL); else if (t->channel_type() != NULL) go_assert(et->channel_type() != NULL || et->points_to() != NULL); else if (t->points_to() != NULL) go_assert(et->points_to() != NULL || et->channel_type() != NULL || et->map_type() != NULL || et->function_type() != NULL || et->integer_type() != NULL || et->is_nil_type()); else if (t->function_type() != NULL) go_assert(et->points_to() != NULL); else if (et->is_unsafe_pointer_type()) go_assert(t->points_to() != NULL || (t->integer_type() != NULL && t->integer_type() == Type::lookup_integer_type("uintptr")->real_type())); else if (t->interface_type() != NULL) { bool empty_iface = t->interface_type()->is_empty(); go_assert(et->interface_type() != NULL && et->interface_type()->is_empty() == empty_iface); } else if (t->integer_type() != NULL) go_assert(et->is_boolean_type() || et->integer_type() != NULL || et->function_type() != NULL || et->points_to() != NULL || et->map_type() != NULL || et->channel_type() != NULL || et->is_nil_type()); else go_unreachable(); Gogo* gogo = context->gogo(); Btype* btype = t->get_backend(gogo); Bexpression* bexpr = this->expr_->get_backend(context); Location loc = this->location(); return gogo->backend()->convert_expression(btype, bexpr, loc); } // Dump ast representation for an unsafe type conversion expression. void Unsafe_type_conversion_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->expr_); ast_dump_context->ostream() << ") "; } // Make an unsafe type conversion expression. Expression* Expression::make_unsafe_cast(Type* type, Expression* expr, Location location) { return new Unsafe_type_conversion_expression(type, expr, location); } // Class Unary_expression. // Call the address_taken method of the operand if needed. This is // called after escape analysis but before inserting write barriers. void Unary_expression::check_operand_address_taken(Gogo*) { if (this->op_ != OPERATOR_AND) return; // If this->escapes_ is false at this point, then it was set to // false by an explicit call to set_does_not_escape, and the value // does not escape. If this->escapes_ is true, we may be able to // set it to false based on the escape analysis pass. if (this->escapes_) { Node* n = Node::make_node(this); if ((n->encoding() & ESCAPE_MASK) == int(Node::ESCAPE_NONE)) this->escapes_ = false; } this->expr_->address_taken(this->escapes_); } // If we are taking the address of a composite literal, and the // contents are not constant, then we want to make a heap expression // instead. Expression* Unary_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int) { Location loc = this->location(); Operator op = this->op_; Expression* expr = this->expr_; if (op == OPERATOR_MULT && expr->is_type_expression()) return Expression::make_type(Type::make_pointer_type(expr->type()), loc); // *&x simplifies to x. *(*T)(unsafe.Pointer)(&x) does not require // moving x to the heap. FIXME: Is it worth doing a real escape // analysis here? This case is found in math/unsafe.go and is // therefore worth special casing. if (op == OPERATOR_MULT) { Expression* e = expr; while (e->classification() == EXPRESSION_CONVERSION) { Type_conversion_expression* te = static_cast(e); e = te->expr(); } if (e->classification() == EXPRESSION_UNARY) { Unary_expression* ue = static_cast(e); if (ue->op_ == OPERATOR_AND) { if (e == expr) { // *&x == x. if (!ue->expr_->is_addressable() && !ue->create_temp_) { go_error_at(ue->location(), "invalid operand for unary %<&%>"); this->set_is_error(); } return ue->expr_; } ue->set_does_not_escape(); } } } // Catching an invalid indirection of unsafe.Pointer here avoid // having to deal with TYPE_VOID in other places. if (op == OPERATOR_MULT && expr->type()->is_unsafe_pointer_type()) { go_error_at(this->location(), "invalid indirect of %"); return Expression::make_error(this->location()); } // Check for an invalid pointer dereference. We need to do this // here because Unary_expression::do_type will return an error type // in this case. That can cause code to appear erroneous, and // therefore disappear at lowering time, without any error message. if (op == OPERATOR_MULT && expr->type()->points_to() == NULL) { this->report_error(_("expected pointer")); return Expression::make_error(this->location()); } if (op == OPERATOR_PLUS || op == OPERATOR_MINUS || op == OPERATOR_XOR) { Numeric_constant nc; if (expr->numeric_constant_value(&nc)) { Numeric_constant result; bool issued_error; if (Unary_expression::eval_constant(op, &nc, loc, &result, &issued_error)) return result.expression(loc); else if (issued_error) return Expression::make_error(this->location()); } } return this; } // Flatten expression if a nil check must be performed and create temporary // variables if necessary. Expression* Unary_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { if (this->is_error_expression() || this->expr_->is_error_expression() || this->expr_->type()->is_error_type()) { go_assert(saw_errors()); return Expression::make_error(this->location()); } Location location = this->location(); if (this->op_ == OPERATOR_MULT && !this->expr_->is_multi_eval_safe()) { go_assert(this->expr_->type()->points_to() != NULL); switch (this->requires_nil_check(gogo)) { case NIL_CHECK_ERROR_ENCOUNTERED: { go_assert(saw_errors()); return Expression::make_error(this->location()); } case NIL_CHECK_NOT_NEEDED: break; case NIL_CHECK_NEEDED: this->create_temp_ = true; break; case NIL_CHECK_DEFAULT: go_unreachable(); } } if (this->create_temp_ && !this->expr_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->expr_, location); inserter->insert(temp); this->expr_ = Expression::make_temporary_reference(temp, location); } return this; } // Return whether a unary expression is a constant. bool Unary_expression::do_is_constant() const { if (this->op_ == OPERATOR_MULT) { // Indirecting through a pointer is only constant if the object // to which the expression points is constant, but we currently // have no way to determine that. return false; } else if (this->op_ == OPERATOR_AND) { // Taking the address of a variable is constant if it is a // global variable, not constant otherwise. In other cases taking the // address is probably not a constant. Var_expression* ve = this->expr_->var_expression(); if (ve != NULL) { Named_object* no = ve->named_object(); return no->is_variable() && no->var_value()->is_global(); } return false; } else return this->expr_->is_constant(); } // Return whether a unary expression can be used as a constant // initializer. bool Unary_expression::do_is_static_initializer() const { if (this->op_ == OPERATOR_MULT) return false; else if (this->op_ == OPERATOR_AND) return Unary_expression::base_is_static_initializer(this->expr_); else return this->expr_->is_static_initializer(); } // Return whether the address of EXPR can be used as a static // initializer. bool Unary_expression::base_is_static_initializer(Expression* expr) { // The address of a field reference can be a static initializer if // the base can be a static initializer. Field_reference_expression* fre = expr->field_reference_expression(); if (fre != NULL) return Unary_expression::base_is_static_initializer(fre->expr()); // The address of an index expression can be a static initializer if // the base can be a static initializer and the index is constant. Array_index_expression* aind = expr->array_index_expression(); if (aind != NULL) return (aind->end() == NULL && aind->start()->is_constant() && Unary_expression::base_is_static_initializer(aind->array())); // The address of a global variable can be a static initializer. Var_expression* ve = expr->var_expression(); if (ve != NULL) { Named_object* no = ve->named_object(); return no->is_variable() && no->var_value()->is_global(); } // The address of a composite literal can be used as a static // initializer if the composite literal is itself usable as a // static initializer. if (expr->is_composite_literal() && expr->is_static_initializer()) return true; // The address of a string constant can be used as a static // initializer. This can not be written in Go itself but this is // used when building a type descriptor. if (expr->string_expression() != NULL) return true; return false; } // Return whether this dereference expression requires an explicit nil // check. If we are dereferencing the pointer to a large struct // (greater than the specified size threshold), we need to check for // nil. We don't bother to check for small structs because we expect // the system to crash on a nil pointer dereference. However, if we // know the address of this expression is being taken, we must always // check for nil. Unary_expression::Nil_check_classification Unary_expression::requires_nil_check(Gogo* gogo) { go_assert(this->op_ == OPERATOR_MULT); go_assert(this->expr_->type()->points_to() != NULL); if (this->issue_nil_check_ == NIL_CHECK_NEEDED) return NIL_CHECK_NEEDED; else if (this->issue_nil_check_ == NIL_CHECK_NOT_NEEDED) return NIL_CHECK_NOT_NEEDED; Type* ptype = this->expr_->type()->points_to(); int64_t type_size = -1; if (!ptype->is_void_type()) { bool ok = ptype->backend_type_size(gogo, &type_size); if (!ok) return NIL_CHECK_ERROR_ENCOUNTERED; } int64_t size_cutoff = gogo->nil_check_size_threshold(); if (size_cutoff == -1 || (type_size != -1 && type_size >= size_cutoff)) this->issue_nil_check_ = NIL_CHECK_NEEDED; else this->issue_nil_check_ = NIL_CHECK_NOT_NEEDED; return this->issue_nil_check_; } // Apply unary opcode OP to UNC, setting NC. Return true if this // could be done, false if not. On overflow, issues an error and sets // *ISSUED_ERROR. bool Unary_expression::eval_constant(Operator op, const Numeric_constant* unc, Location location, Numeric_constant* nc, bool* issued_error) { *issued_error = false; switch (op) { case OPERATOR_PLUS: *nc = *unc; return true; case OPERATOR_MINUS: if (unc->is_int() || unc->is_rune()) break; else if (unc->is_float()) { mpfr_t uval; unc->get_float(&uval); mpfr_t val; mpfr_init(val); mpfr_neg(val, uval, MPFR_RNDN); nc->set_float(unc->type(), val); mpfr_clear(uval); mpfr_clear(val); return true; } else if (unc->is_complex()) { mpc_t uval; unc->get_complex(&uval); mpc_t val; mpc_init2(val, mpc_precision); mpc_neg(val, uval, MPC_RNDNN); nc->set_complex(unc->type(), val); mpc_clear(uval); mpc_clear(val); return true; } else go_unreachable(); case OPERATOR_XOR: break; case OPERATOR_NOT: case OPERATOR_AND: case OPERATOR_MULT: return false; default: go_unreachable(); } if (!unc->is_int() && !unc->is_rune()) return false; mpz_t uval; if (unc->is_rune()) unc->get_rune(&uval); else unc->get_int(&uval); mpz_t val; mpz_init(val); switch (op) { case OPERATOR_MINUS: mpz_neg(val, uval); break; case OPERATOR_NOT: mpz_set_ui(val, mpz_cmp_si(uval, 0) == 0 ? 1 : 0); break; case OPERATOR_XOR: { Type* utype = unc->type(); if (utype->integer_type() == NULL || utype->integer_type()->is_abstract()) mpz_com(val, uval); else { // The number of HOST_WIDE_INTs that it takes to represent // UVAL. size_t count = ((mpz_sizeinbase(uval, 2) + HOST_BITS_PER_WIDE_INT - 1) / HOST_BITS_PER_WIDE_INT); unsigned HOST_WIDE_INT* phwi = new unsigned HOST_WIDE_INT[count]; memset(phwi, 0, count * sizeof(HOST_WIDE_INT)); size_t obits = utype->integer_type()->bits(); if (!utype->integer_type()->is_unsigned() && mpz_sgn(uval) < 0) { mpz_t adj; mpz_init_set_ui(adj, 1); mpz_mul_2exp(adj, adj, obits); mpz_add(uval, uval, adj); mpz_clear(adj); } size_t ecount; mpz_export(phwi, &ecount, -1, sizeof(HOST_WIDE_INT), 0, 0, uval); go_assert(ecount <= count); // Trim down to the number of words required by the type. size_t ocount = ((obits + HOST_BITS_PER_WIDE_INT - 1) / HOST_BITS_PER_WIDE_INT); go_assert(ocount <= count); for (size_t i = 0; i < ocount; ++i) phwi[i] = ~phwi[i]; size_t clearbits = ocount * HOST_BITS_PER_WIDE_INT - obits; if (clearbits != 0) phwi[ocount - 1] &= (((unsigned HOST_WIDE_INT) (HOST_WIDE_INT) -1) >> clearbits); mpz_import(val, ocount, -1, sizeof(HOST_WIDE_INT), 0, 0, phwi); if (!utype->integer_type()->is_unsigned() && mpz_tstbit(val, obits - 1)) { mpz_t adj; mpz_init_set_ui(adj, 1); mpz_mul_2exp(adj, adj, obits); mpz_sub(val, val, adj); mpz_clear(adj); } delete[] phwi; } } break; default: go_unreachable(); } if (unc->is_rune()) nc->set_rune(NULL, val); else nc->set_int(NULL, val); mpz_clear(uval); mpz_clear(val); if (!nc->set_type(unc->type(), true, location)) { *issued_error = true; return false; } return true; } // Return the integral constant value of a unary expression, if it has one. bool Unary_expression::do_numeric_constant_value(Numeric_constant* nc) const { Numeric_constant unc; if (!this->expr_->numeric_constant_value(&unc)) return false; bool issued_error; return Unary_expression::eval_constant(this->op_, &unc, this->location(), nc, &issued_error); } // Return the boolean constant value of a unary expression, if it has one. bool Unary_expression::do_boolean_constant_value(bool* val) const { if (this->op_ == OPERATOR_NOT && this->expr_->boolean_constant_value(val)) { *val = !*val; return true; } return false; } // Return the type of a unary expression. Type* Unary_expression::do_type() { switch (this->op_) { case OPERATOR_PLUS: case OPERATOR_MINUS: case OPERATOR_NOT: case OPERATOR_XOR: return this->expr_->type(); case OPERATOR_AND: return Type::make_pointer_type(this->expr_->type()); case OPERATOR_MULT: { Type* subtype = this->expr_->type(); Type* points_to = subtype->points_to(); if (points_to == NULL) return Type::make_error_type(); return points_to; } default: go_unreachable(); } } // Determine abstract types for a unary expression. void Unary_expression::do_determine_type(const Type_context* context) { switch (this->op_) { case OPERATOR_PLUS: case OPERATOR_MINUS: case OPERATOR_NOT: case OPERATOR_XOR: this->expr_->determine_type(context); break; case OPERATOR_AND: // Taking the address of something. { Type* subtype = (context->type == NULL ? NULL : context->type->points_to()); Type_context subcontext(subtype, false); this->expr_->determine_type(&subcontext); } break; case OPERATOR_MULT: // Indirecting through a pointer. { Type* subtype = (context->type == NULL ? NULL : Type::make_pointer_type(context->type)); Type_context subcontext(subtype, false); this->expr_->determine_type(&subcontext); } break; default: go_unreachable(); } } // Check types for a unary expression. void Unary_expression::do_check_types(Gogo*) { Type* type = this->expr_->type(); if (type->is_error()) { this->set_is_error(); return; } switch (this->op_) { case OPERATOR_PLUS: case OPERATOR_MINUS: if (type->integer_type() == NULL && type->float_type() == NULL && type->complex_type() == NULL) this->report_error(_("expected numeric type")); break; case OPERATOR_NOT: if (!type->is_boolean_type()) this->report_error(_("expected boolean type")); break; case OPERATOR_XOR: if (type->integer_type() == NULL) this->report_error(_("expected integer")); break; case OPERATOR_AND: if (!this->expr_->is_addressable()) { if (!this->create_temp_) { go_error_at(this->location(), "invalid operand for unary %<&%>"); this->set_is_error(); } } else this->expr_->issue_nil_check(); break; case OPERATOR_MULT: // Indirecting through a pointer. if (type->points_to() == NULL) this->report_error(_("expected pointer")); if (type->points_to()->is_error()) this->set_is_error(); break; default: go_unreachable(); } } // Get the backend representation for a unary expression. Bexpression* Unary_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Location loc = this->location(); // Taking the address of a set-and-use-temporary expression requires // setting the temporary and then taking the address. if (this->op_ == OPERATOR_AND) { Set_and_use_temporary_expression* sut = this->expr_->set_and_use_temporary_expression(); if (sut != NULL) { Temporary_statement* temp = sut->temporary(); Bvariable* bvar = temp->get_backend_variable(context); Bexpression* bvar_expr = gogo->backend()->var_expression(bvar, loc); Bexpression* bval = sut->expression()->get_backend(context); Named_object* fn = context->function(); go_assert(fn != NULL); Bfunction* bfn = fn->func_value()->get_or_make_decl(gogo, fn); Bstatement* bassign = gogo->backend()->assignment_statement(bfn, bvar_expr, bval, loc); Bexpression* bvar_addr = gogo->backend()->address_expression(bvar_expr, loc); return gogo->backend()->compound_expression(bassign, bvar_addr, loc); } } Bexpression* ret; Bexpression* bexpr = this->expr_->get_backend(context); Btype* btype = this->expr_->type()->get_backend(gogo); switch (this->op_) { case OPERATOR_PLUS: ret = bexpr; break; case OPERATOR_MINUS: ret = gogo->backend()->unary_expression(this->op_, bexpr, loc); ret = gogo->backend()->convert_expression(btype, ret, loc); break; case OPERATOR_NOT: case OPERATOR_XOR: ret = gogo->backend()->unary_expression(this->op_, bexpr, loc); break; case OPERATOR_AND: if (!this->create_temp_) { // We should not see a non-constant constructor here; cases // where we would see one should have been moved onto the // heap at parse time. Taking the address of a nonconstant // constructor will not do what the programmer expects. go_assert(!this->expr_->is_composite_literal() || this->expr_->is_static_initializer()); if (this->expr_->classification() == EXPRESSION_UNARY) { Unary_expression* ue = static_cast(this->expr_); go_assert(ue->op() != OPERATOR_AND); } } if (this->is_gc_root_ || this->is_slice_init_) { std::string var_name; bool copy_to_heap = false; if (this->is_gc_root_) { // Build a decl for a GC root variable. GC roots are mutable, so // they cannot be represented as an immutable_struct in the // backend. var_name = gogo->gc_root_name(); } else { // Build a decl for a slice value initializer. An immutable slice // value initializer may have to be copied to the heap if it // contains pointers in a non-constant context. var_name = gogo->initializer_name(); Array_type* at = this->expr_->type()->array_type(); go_assert(at != NULL); // If we are not copying the value to the heap, we will only // initialize the value once, so we can use this directly // rather than copying it. In that case we can't make it // read-only, because the program is permitted to change it. copy_to_heap = (context->function() != NULL || context->is_const()); } unsigned int flags = (Backend::variable_is_hidden | Backend::variable_address_is_taken); if (copy_to_heap) flags |= Backend::variable_is_constant; Bvariable* implicit = gogo->backend()->implicit_variable(var_name, "", btype, flags, 0); gogo->backend()->implicit_variable_set_init(implicit, var_name, btype, flags, bexpr); bexpr = gogo->backend()->var_expression(implicit, loc); // If we are not copying a slice initializer to the heap, // then it can be changed by the program, so if it can // contain pointers we must register it as a GC root. if (this->is_slice_init_ && !copy_to_heap && this->expr_->type()->has_pointer()) { Bexpression* root = gogo->backend()->var_expression(implicit, loc); root = gogo->backend()->address_expression(root, loc); Type* type = Type::make_pointer_type(this->expr_->type()); gogo->add_gc_root(Expression::make_backend(root, type, loc)); } } else if ((this->expr_->is_composite_literal() || this->expr_->string_expression() != NULL) && this->expr_->is_static_initializer()) { std::string var_name(gogo->initializer_name()); unsigned int flags = (Backend::variable_is_hidden | Backend::variable_address_is_taken); Bvariable* decl = gogo->backend()->immutable_struct(var_name, "", flags, btype, loc); gogo->backend()->immutable_struct_set_init(decl, var_name, flags, btype, loc, bexpr); bexpr = gogo->backend()->var_expression(decl, loc); } else if (this->expr_->is_constant()) { std::string var_name(gogo->initializer_name()); unsigned int flags = (Backend::variable_is_hidden | Backend::variable_is_constant | Backend::variable_address_is_taken); Bvariable* decl = gogo->backend()->implicit_variable(var_name, "", btype, flags, 0); gogo->backend()->implicit_variable_set_init(decl, var_name, btype, flags, bexpr); bexpr = gogo->backend()->var_expression(decl, loc); } go_assert(!this->create_temp_ || this->expr_->is_multi_eval_safe()); ret = gogo->backend()->address_expression(bexpr, loc); break; case OPERATOR_MULT: { go_assert(this->expr_->type()->points_to() != NULL); Type* ptype = this->expr_->type()->points_to(); Btype* pbtype = ptype->get_backend(gogo); switch (this->requires_nil_check(gogo)) { case NIL_CHECK_NOT_NEEDED: break; case NIL_CHECK_ERROR_ENCOUNTERED: { go_assert(saw_errors()); return gogo->backend()->error_expression(); } case NIL_CHECK_NEEDED: { go_assert(this->expr_->is_multi_eval_safe()); // If we're nil-checking the result of a set-and-use-temporary // expression, then pick out the target temp and use that // for the final result of the conditional. Bexpression* tbexpr = bexpr; Bexpression* ubexpr = bexpr; Set_and_use_temporary_expression* sut = this->expr_->set_and_use_temporary_expression(); if (sut != NULL) { Temporary_statement* temp = sut->temporary(); Bvariable* bvar = temp->get_backend_variable(context); ubexpr = gogo->backend()->var_expression(bvar, loc); } Bexpression* nil = Expression::make_nil(loc)->get_backend(context); Bexpression* compare = gogo->backend()->binary_expression(OPERATOR_EQEQ, tbexpr, nil, loc); Expression* crash = Runtime::make_call(Runtime::PANIC_MEM, loc, 0); Bexpression* bcrash = crash->get_backend(context); Bfunction* bfn = context->function()->func_value()->get_decl(); bexpr = gogo->backend()->conditional_expression(bfn, btype, compare, bcrash, ubexpr, loc); break; } case NIL_CHECK_DEFAULT: go_unreachable(); } ret = gogo->backend()->indirect_expression(pbtype, bexpr, false, loc); } break; default: go_unreachable(); } return ret; } // Export a unary expression. void Unary_expression::do_export(Export_function_body* efb) const { switch (this->op_) { case OPERATOR_PLUS: efb->write_c_string("+"); break; case OPERATOR_MINUS: efb->write_c_string("-"); break; case OPERATOR_NOT: efb->write_c_string("!"); break; case OPERATOR_XOR: efb->write_c_string("^"); break; case OPERATOR_AND: efb->write_c_string("&"); break; case OPERATOR_MULT: efb->write_c_string("*"); break; default: go_unreachable(); } this->expr_->export_expression(efb); } // Import a unary expression. Expression* Unary_expression::do_import(Import_expression* imp, Location loc) { Operator op; switch (imp->get_char()) { case '+': op = OPERATOR_PLUS; break; case '-': op = OPERATOR_MINUS; break; case '!': op = OPERATOR_NOT; break; case '^': op = OPERATOR_XOR; break; case '&': op = OPERATOR_AND; break; case '*': op = OPERATOR_MULT; break; default: go_unreachable(); } if (imp->version() < EXPORT_FORMAT_V3) imp->require_c_string(" "); Expression* expr = Expression::import_expression(imp, loc); return Expression::make_unary(op, expr, loc); } // Dump ast representation of an unary expression. void Unary_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_operator(this->op_); ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->expr_); ast_dump_context->ostream() << ") "; } // Make a unary expression. Expression* Expression::make_unary(Operator op, Expression* expr, Location location) { return new Unary_expression(op, expr, location); } Expression* Expression::make_dereference(Expression* ptr, Nil_check_classification docheck, Location location) { Expression* deref = Expression::make_unary(OPERATOR_MULT, ptr, location); if (docheck == NIL_CHECK_NEEDED) deref->unary_expression()->set_requires_nil_check(true); else if (docheck == NIL_CHECK_NOT_NEEDED) deref->unary_expression()->set_requires_nil_check(false); return deref; } // If this is an indirection through a pointer, return the expression // being pointed through. Otherwise return this. Expression* Expression::deref() { if (this->classification_ == EXPRESSION_UNARY) { Unary_expression* ue = static_cast(this); if (ue->op() == OPERATOR_MULT) return ue->operand(); } return this; } // Class Binary_expression. // Traversal. int Binary_expression::do_traverse(Traverse* traverse) { int t = Expression::traverse(&this->left_, traverse); if (t == TRAVERSE_EXIT) return TRAVERSE_EXIT; return Expression::traverse(&this->right_, traverse); } // Return whether this expression may be used as a static initializer. bool Binary_expression::do_is_static_initializer() const { if (!this->left_->is_static_initializer() || !this->right_->is_static_initializer()) return false; // Addresses can be static initializers, but we can't implement // arbitray binary expressions of them. Unary_expression* lu = this->left_->unary_expression(); Unary_expression* ru = this->right_->unary_expression(); if (lu != NULL && lu->op() == OPERATOR_AND) { if (ru != NULL && ru->op() == OPERATOR_AND) return this->op_ == OPERATOR_MINUS; else return this->op_ == OPERATOR_PLUS || this->op_ == OPERATOR_MINUS; } else if (ru != NULL && ru->op() == OPERATOR_AND) return this->op_ == OPERATOR_PLUS || this->op_ == OPERATOR_MINUS; // Other cases should resolve in the backend. return true; } // Return the type to use for a binary operation on operands of // LEFT_TYPE and RIGHT_TYPE. These are the types of constants and as // such may be NULL or abstract. bool Binary_expression::operation_type(Operator op, Type* left_type, Type* right_type, Type** result_type) { if (left_type != right_type && !left_type->is_abstract() && !right_type->is_abstract() && left_type->base() != right_type->base() && op != OPERATOR_LSHIFT && op != OPERATOR_RSHIFT) { // May be a type error--let it be diagnosed elsewhere. return false; } if (op == OPERATOR_LSHIFT || op == OPERATOR_RSHIFT) { if (left_type->integer_type() != NULL) *result_type = left_type; else *result_type = Type::make_abstract_integer_type(); } else if (!left_type->is_abstract() && left_type->named_type() != NULL) *result_type = left_type; else if (!right_type->is_abstract() && right_type->named_type() != NULL) *result_type = right_type; else if (!left_type->is_abstract()) *result_type = left_type; else if (!right_type->is_abstract()) *result_type = right_type; else if (left_type->complex_type() != NULL) *result_type = left_type; else if (right_type->complex_type() != NULL) *result_type = right_type; else if (left_type->float_type() != NULL) *result_type = left_type; else if (right_type->float_type() != NULL) *result_type = right_type; else if (left_type->integer_type() != NULL && left_type->integer_type()->is_rune()) *result_type = left_type; else if (right_type->integer_type() != NULL && right_type->integer_type()->is_rune()) *result_type = right_type; else *result_type = left_type; return true; } // Convert an integer comparison code and an operator to a boolean // value. bool Binary_expression::cmp_to_bool(Operator op, int cmp) { switch (op) { case OPERATOR_EQEQ: return cmp == 0; break; case OPERATOR_NOTEQ: return cmp != 0; break; case OPERATOR_LT: return cmp < 0; break; case OPERATOR_LE: return cmp <= 0; case OPERATOR_GT: return cmp > 0; case OPERATOR_GE: return cmp >= 0; default: go_unreachable(); } } // Compare constants according to OP. bool Binary_expression::compare_constant(Operator op, Numeric_constant* left_nc, Numeric_constant* right_nc, Location location, bool* result) { Type* left_type = left_nc->type(); Type* right_type = right_nc->type(); Type* type; if (!Binary_expression::operation_type(op, left_type, right_type, &type)) return false; // When comparing an untyped operand to a typed operand, we are // effectively coercing the untyped operand to the other operand's // type, so make sure that is valid. if (!left_nc->set_type(type, true, location) || !right_nc->set_type(type, true, location)) return false; bool ret; int cmp; if (type->complex_type() != NULL) { if (op != OPERATOR_EQEQ && op != OPERATOR_NOTEQ) return false; ret = Binary_expression::compare_complex(left_nc, right_nc, &cmp); } else if (type->float_type() != NULL) ret = Binary_expression::compare_float(left_nc, right_nc, &cmp); else ret = Binary_expression::compare_integer(left_nc, right_nc, &cmp); if (ret) *result = Binary_expression::cmp_to_bool(op, cmp); return ret; } // Compare integer constants. bool Binary_expression::compare_integer(const Numeric_constant* left_nc, const Numeric_constant* right_nc, int* cmp) { mpz_t left_val; if (!left_nc->to_int(&left_val)) return false; mpz_t right_val; if (!right_nc->to_int(&right_val)) { mpz_clear(left_val); return false; } *cmp = mpz_cmp(left_val, right_val); mpz_clear(left_val); mpz_clear(right_val); return true; } // Compare floating point constants. bool Binary_expression::compare_float(const Numeric_constant* left_nc, const Numeric_constant* right_nc, int* cmp) { mpfr_t left_val; if (!left_nc->to_float(&left_val)) return false; mpfr_t right_val; if (!right_nc->to_float(&right_val)) { mpfr_clear(left_val); return false; } // We already coerced both operands to the same type. If that type // is not an abstract type, we need to round the values accordingly. Type* type = left_nc->type(); if (!type->is_abstract() && type->float_type() != NULL) { int bits = type->float_type()->bits(); mpfr_prec_round(left_val, bits, MPFR_RNDN); mpfr_prec_round(right_val, bits, MPFR_RNDN); } *cmp = mpfr_cmp(left_val, right_val); mpfr_clear(left_val); mpfr_clear(right_val); return true; } // Compare complex constants. Complex numbers may only be compared // for equality. bool Binary_expression::compare_complex(const Numeric_constant* left_nc, const Numeric_constant* right_nc, int* cmp) { mpc_t left_val; if (!left_nc->to_complex(&left_val)) return false; mpc_t right_val; if (!right_nc->to_complex(&right_val)) { mpc_clear(left_val); return false; } // We already coerced both operands to the same type. If that type // is not an abstract type, we need to round the values accordingly. Type* type = left_nc->type(); if (!type->is_abstract() && type->complex_type() != NULL) { int bits = type->complex_type()->bits(); mpfr_prec_round(mpc_realref(left_val), bits / 2, MPFR_RNDN); mpfr_prec_round(mpc_imagref(left_val), bits / 2, MPFR_RNDN); mpfr_prec_round(mpc_realref(right_val), bits / 2, MPFR_RNDN); mpfr_prec_round(mpc_imagref(right_val), bits / 2, MPFR_RNDN); } *cmp = mpc_cmp(left_val, right_val) != 0; mpc_clear(left_val); mpc_clear(right_val); return true; } // Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC. Return // true if this could be done, false if not. Issue errors at LOCATION // as appropriate, and sets *ISSUED_ERROR if it did. bool Binary_expression::eval_constant(Operator op, Numeric_constant* left_nc, Numeric_constant* right_nc, Location location, Numeric_constant* nc, bool* issued_error) { *issued_error = false; switch (op) { case OPERATOR_OROR: case OPERATOR_ANDAND: case OPERATOR_EQEQ: case OPERATOR_NOTEQ: case OPERATOR_LT: case OPERATOR_LE: case OPERATOR_GT: case OPERATOR_GE: // These return boolean values, not numeric. return false; default: break; } Type* left_type = left_nc->type(); Type* right_type = right_nc->type(); Type* type; if (!Binary_expression::operation_type(op, left_type, right_type, &type)) return false; bool is_shift = op == OPERATOR_LSHIFT || op == OPERATOR_RSHIFT; // When combining an untyped operand with a typed operand, we are // effectively coercing the untyped operand to the other operand's // type, so make sure that is valid. if (!left_nc->set_type(type, true, location)) return false; if (!is_shift && !right_nc->set_type(type, true, location)) return false; if (is_shift && ((left_type->integer_type() == NULL && !left_type->is_abstract()) || (right_type->integer_type() == NULL && !right_type->is_abstract()))) return false; bool r; if (type->complex_type() != NULL) r = Binary_expression::eval_complex(op, left_nc, right_nc, location, nc); else if (type->float_type() != NULL) r = Binary_expression::eval_float(op, left_nc, right_nc, location, nc); else r = Binary_expression::eval_integer(op, left_nc, right_nc, location, nc); if (r) { r = nc->set_type(type, true, location); if (!r) *issued_error = true; } return r; } // Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC, using // integer operations. Return true if this could be done, false if // not. bool Binary_expression::eval_integer(Operator op, const Numeric_constant* left_nc, const Numeric_constant* right_nc, Location location, Numeric_constant* nc) { mpz_t left_val; if (!left_nc->to_int(&left_val)) return false; mpz_t right_val; if (!right_nc->to_int(&right_val)) { mpz_clear(left_val); return false; } mpz_t val; mpz_init(val); switch (op) { case OPERATOR_PLUS: mpz_add(val, left_val, right_val); if (mpz_sizeinbase(val, 2) > 0x100000) { go_error_at(location, "constant addition overflow"); nc->set_invalid(); mpz_set_ui(val, 1); } break; case OPERATOR_MINUS: mpz_sub(val, left_val, right_val); if (mpz_sizeinbase(val, 2) > 0x100000) { go_error_at(location, "constant subtraction overflow"); nc->set_invalid(); mpz_set_ui(val, 1); } break; case OPERATOR_OR: mpz_ior(val, left_val, right_val); break; case OPERATOR_XOR: mpz_xor(val, left_val, right_val); break; case OPERATOR_MULT: mpz_mul(val, left_val, right_val); if (mpz_sizeinbase(val, 2) > 0x100000) { go_error_at(location, "constant multiplication overflow"); nc->set_invalid(); mpz_set_ui(val, 1); } break; case OPERATOR_DIV: if (mpz_sgn(right_val) != 0) mpz_tdiv_q(val, left_val, right_val); else { go_error_at(location, "division by zero"); nc->set_invalid(); mpz_set_ui(val, 0); } break; case OPERATOR_MOD: if (mpz_sgn(right_val) != 0) mpz_tdiv_r(val, left_val, right_val); else { go_error_at(location, "division by zero"); nc->set_invalid(); mpz_set_ui(val, 0); } break; case OPERATOR_LSHIFT: { unsigned long shift = mpz_get_ui(right_val); if (mpz_cmp_ui(right_val, shift) == 0 && shift <= 0x100000) mpz_mul_2exp(val, left_val, shift); else { go_error_at(location, "shift count overflow"); nc->set_invalid(); mpz_set_ui(val, 1); } break; } break; case OPERATOR_RSHIFT: { unsigned long shift = mpz_get_ui(right_val); if (mpz_cmp_ui(right_val, shift) != 0) { go_error_at(location, "shift count overflow"); nc->set_invalid(); mpz_set_ui(val, 1); } else { if (mpz_cmp_ui(left_val, 0) >= 0) mpz_tdiv_q_2exp(val, left_val, shift); else mpz_fdiv_q_2exp(val, left_val, shift); } break; } break; case OPERATOR_AND: mpz_and(val, left_val, right_val); break; case OPERATOR_BITCLEAR: { mpz_t tval; mpz_init(tval); mpz_com(tval, right_val); mpz_and(val, left_val, tval); mpz_clear(tval); } break; default: go_unreachable(); } mpz_clear(left_val); mpz_clear(right_val); if (left_nc->is_rune() || (op != OPERATOR_LSHIFT && op != OPERATOR_RSHIFT && right_nc->is_rune())) nc->set_rune(NULL, val); else nc->set_int(NULL, val); mpz_clear(val); return true; } // Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC, using // floating point operations. Return true if this could be done, // false if not. bool Binary_expression::eval_float(Operator op, const Numeric_constant* left_nc, const Numeric_constant* right_nc, Location location, Numeric_constant* nc) { mpfr_t left_val; if (!left_nc->to_float(&left_val)) return false; mpfr_t right_val; if (!right_nc->to_float(&right_val)) { mpfr_clear(left_val); return false; } mpfr_t val; mpfr_init(val); bool ret = true; switch (op) { case OPERATOR_PLUS: mpfr_add(val, left_val, right_val, MPFR_RNDN); break; case OPERATOR_MINUS: mpfr_sub(val, left_val, right_val, MPFR_RNDN); break; case OPERATOR_OR: case OPERATOR_XOR: case OPERATOR_AND: case OPERATOR_BITCLEAR: case OPERATOR_MOD: case OPERATOR_LSHIFT: case OPERATOR_RSHIFT: mpfr_set_ui(val, 0, MPFR_RNDN); ret = false; break; case OPERATOR_MULT: mpfr_mul(val, left_val, right_val, MPFR_RNDN); break; case OPERATOR_DIV: if (!mpfr_zero_p(right_val)) mpfr_div(val, left_val, right_val, MPFR_RNDN); else { go_error_at(location, "division by zero"); nc->set_invalid(); mpfr_set_ui(val, 0, MPFR_RNDN); } break; default: go_unreachable(); } mpfr_clear(left_val); mpfr_clear(right_val); nc->set_float(NULL, val); mpfr_clear(val); return ret; } // Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC, using // complex operations. Return true if this could be done, false if // not. bool Binary_expression::eval_complex(Operator op, const Numeric_constant* left_nc, const Numeric_constant* right_nc, Location location, Numeric_constant* nc) { mpc_t left_val; if (!left_nc->to_complex(&left_val)) return false; mpc_t right_val; if (!right_nc->to_complex(&right_val)) { mpc_clear(left_val); return false; } mpc_t val; mpc_init2(val, mpc_precision); bool ret = true; switch (op) { case OPERATOR_PLUS: mpc_add(val, left_val, right_val, MPC_RNDNN); break; case OPERATOR_MINUS: mpc_sub(val, left_val, right_val, MPC_RNDNN); break; case OPERATOR_OR: case OPERATOR_XOR: case OPERATOR_AND: case OPERATOR_BITCLEAR: case OPERATOR_MOD: case OPERATOR_LSHIFT: case OPERATOR_RSHIFT: mpc_set_ui(val, 0, MPC_RNDNN); ret = false; break; case OPERATOR_MULT: mpc_mul(val, left_val, right_val, MPC_RNDNN); break; case OPERATOR_DIV: if (mpc_cmp_si(right_val, 0) == 0) { go_error_at(location, "division by zero"); nc->set_invalid(); mpc_set_ui(val, 0, MPC_RNDNN); break; } mpc_div(val, left_val, right_val, MPC_RNDNN); break; default: go_unreachable(); } mpc_clear(left_val); mpc_clear(right_val); nc->set_complex(NULL, val); mpc_clear(val); return ret; } // Lower a binary expression. We have to evaluate constant // expressions now, in order to implement Go's unlimited precision // constants. Expression* Binary_expression::do_lower(Gogo* gogo, Named_object*, Statement_inserter* inserter, int) { Location location = this->location(); Operator op = this->op_; Expression* left = this->left_; Expression* right = this->right_; const bool is_comparison = (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ || op == OPERATOR_LT || op == OPERATOR_LE || op == OPERATOR_GT || op == OPERATOR_GE); // Numeric constant expressions. { Numeric_constant left_nc; Numeric_constant right_nc; if (left->numeric_constant_value(&left_nc) && right->numeric_constant_value(&right_nc)) { if (is_comparison) { bool result; if (!Binary_expression::compare_constant(op, &left_nc, &right_nc, location, &result)) return this; return Expression::make_boolean(result, location); } else { Numeric_constant nc; bool issued_error; if (!Binary_expression::eval_constant(op, &left_nc, &right_nc, location, &nc, &issued_error)) { if (issued_error) return Expression::make_error(location); return this; } return nc.expression(location); } } } // String constant expressions. // // Avoid constant folding here if the left and right types are incompatible // (leave the operation intact so that the type checker can complain about it // later on). If concatenating an abstract string with a named string type, // result type needs to be of the named type (see issue 31412). if (left->type()->is_string_type() && right->type()->is_string_type() && (left->type()->named_type() == NULL || right->type()->named_type() == NULL || left->type()->named_type() == right->type()->named_type())) { std::string left_string; std::string right_string; if (left->string_constant_value(&left_string) && right->string_constant_value(&right_string)) { if (op == OPERATOR_PLUS) { Type* result_type = (left->type()->named_type() != NULL ? left->type() : right->type()); delete left; delete right; return Expression::make_string_typed(left_string + right_string, result_type, location); } else if (is_comparison) { int cmp = left_string.compare(right_string); bool r = Binary_expression::cmp_to_bool(op, cmp); delete left; delete right; return Expression::make_boolean(r, location); } } } // Lower struct, array, and some interface comparisons. if (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ) { if (left->type()->struct_type() != NULL && right->type()->struct_type() != NULL) return this->lower_struct_comparison(gogo, inserter); else if (left->type()->array_type() != NULL && !left->type()->is_slice_type() && right->type()->array_type() != NULL && !right->type()->is_slice_type()) return this->lower_array_comparison(gogo, inserter); else if ((left->type()->interface_type() != NULL && right->type()->interface_type() == NULL) || (left->type()->interface_type() == NULL && right->type()->interface_type() != NULL)) return this->lower_interface_value_comparison(gogo, inserter); } // Lower string concatenation to String_concat_expression, so that // we can group sequences of string additions. if (this->left_->type()->is_string_type() && this->op_ == OPERATOR_PLUS) { Expression_list* exprs; String_concat_expression* left_sce = this->left_->string_concat_expression(); if (left_sce != NULL) exprs = left_sce->exprs(); else { exprs = new Expression_list(); exprs->push_back(this->left_); } String_concat_expression* right_sce = this->right_->string_concat_expression(); if (right_sce != NULL) exprs->append(right_sce->exprs()); else exprs->push_back(this->right_); return Expression::make_string_concat(exprs); } return this; } // Lower a struct comparison. Expression* Binary_expression::lower_struct_comparison(Gogo* gogo, Statement_inserter* inserter) { Struct_type* st = this->left_->type()->struct_type(); Struct_type* st2 = this->right_->type()->struct_type(); if (st2 == NULL) return this; if (st != st2 && !Type::are_identical(st, st2, Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) return this; if (!Type::are_compatible_for_comparison(true, this->left_->type(), this->right_->type(), NULL)) return this; // See if we can compare using memcmp. As a heuristic, we use // memcmp rather than field references and comparisons if there are // more than two fields. if (st->compare_is_identity(gogo) && st->total_field_count() > 2) return this->lower_compare_to_memcmp(gogo, inserter); Location loc = this->location(); Expression* left = this->left_; Temporary_statement* left_temp = NULL; if (left->var_expression() == NULL && left->temporary_reference_expression() == NULL) { left_temp = Statement::make_temporary(left->type(), NULL, loc); inserter->insert(left_temp); left = Expression::make_set_and_use_temporary(left_temp, left, loc); } Expression* right = this->right_; Temporary_statement* right_temp = NULL; if (right->var_expression() == NULL && right->temporary_reference_expression() == NULL) { right_temp = Statement::make_temporary(right->type(), NULL, loc); inserter->insert(right_temp); right = Expression::make_set_and_use_temporary(right_temp, right, loc); } Expression* ret = Expression::make_boolean(true, loc); const Struct_field_list* fields = st->fields(); unsigned int field_index = 0; for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf, ++field_index) { if (Gogo::is_sink_name(pf->field_name())) continue; if (field_index > 0) { if (left_temp == NULL) left = left->copy(); else left = Expression::make_temporary_reference(left_temp, loc); if (right_temp == NULL) right = right->copy(); else right = Expression::make_temporary_reference(right_temp, loc); } Expression* f1 = Expression::make_field_reference(left, field_index, loc); Expression* f2 = Expression::make_field_reference(right, field_index, loc); Expression* cond = Expression::make_binary(OPERATOR_EQEQ, f1, f2, loc); ret = Expression::make_binary(OPERATOR_ANDAND, ret, cond, loc); } if (this->op_ == OPERATOR_NOTEQ) ret = Expression::make_unary(OPERATOR_NOT, ret, loc); return ret; } // Lower an array comparison. Expression* Binary_expression::lower_array_comparison(Gogo* gogo, Statement_inserter* inserter) { Array_type* at = this->left_->type()->array_type(); Array_type* at2 = this->right_->type()->array_type(); if (at2 == NULL) return this; if (at != at2 && !Type::are_identical(at, at2, Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) return this; if (!Type::are_compatible_for_comparison(true, this->left_->type(), this->right_->type(), NULL)) return this; // Call memcmp directly if possible. This may let the middle-end // optimize the call. if (at->compare_is_identity(gogo)) return this->lower_compare_to_memcmp(gogo, inserter); // Call the array comparison function. Named_object* equal_fn = at->equal_function(gogo, this->left_->type()->named_type(), NULL); Location loc = this->location(); Expression* func = Expression::make_func_reference(equal_fn, NULL, loc); Expression_list* args = new Expression_list(); args->push_back(this->operand_address(inserter, this->left_)); args->push_back(this->operand_address(inserter, this->right_)); Call_expression* ce = Expression::make_call(func, args, false, loc); // Record that this is a call to a generated equality function. We // need to do this because a comparison returns an abstract boolean // type, but the function necessarily returns "bool". The // difference shows up in code like // type mybool bool // var b mybool = [10]string{} == [10]string{} // The comparison function returns "bool", but since a comparison // has an abstract boolean type we need an implicit conversion to // "mybool". The implicit conversion is inserted in // Call_expression::do_flatten. ce->set_is_equal_function(); Expression* ret = ce; if (this->op_ == OPERATOR_NOTEQ) ret = Expression::make_unary(OPERATOR_NOT, ret, loc); return ret; } // Lower an interface to value comparison. Expression* Binary_expression::lower_interface_value_comparison(Gogo*, Statement_inserter* inserter) { Type* left_type = this->left_->type(); Type* right_type = this->right_->type(); Interface_type* ift; if (left_type->interface_type() != NULL) { ift = left_type->interface_type(); if (!ift->implements_interface(right_type, NULL)) return this; } else { ift = right_type->interface_type(); if (!ift->implements_interface(left_type, NULL)) return this; } if (!Type::are_compatible_for_comparison(true, left_type, right_type, NULL)) return this; Location loc = this->location(); if (left_type->interface_type() == NULL && left_type->points_to() == NULL && !this->left_->is_addressable()) { Temporary_statement* temp = Statement::make_temporary(left_type, NULL, loc); inserter->insert(temp); this->left_ = Expression::make_set_and_use_temporary(temp, this->left_, loc); } if (right_type->interface_type() == NULL && right_type->points_to() == NULL && !this->right_->is_addressable()) { Temporary_statement* temp = Statement::make_temporary(right_type, NULL, loc); inserter->insert(temp); this->right_ = Expression::make_set_and_use_temporary(temp, this->right_, loc); } return this; } // Lower a struct or array comparison to a call to memcmp. Expression* Binary_expression::lower_compare_to_memcmp(Gogo*, Statement_inserter* inserter) { Location loc = this->location(); Expression* a1 = this->operand_address(inserter, this->left_); Expression* a2 = this->operand_address(inserter, this->right_); Expression* len = Expression::make_type_info(this->left_->type(), TYPE_INFO_SIZE); Expression* call = Runtime::make_call(Runtime::MEMCMP, loc, 3, a1, a2, len); Type* int32_type = Type::lookup_integer_type("int32"); Expression* zero = Expression::make_integer_ul(0, int32_type, loc); return Expression::make_binary(this->op_, call, zero, loc); } Expression* Binary_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { Location loc = this->location(); if (this->left_->type()->is_error_type() || this->right_->type()->is_error_type() || this->left_->is_error_expression() || this->right_->is_error_expression()) { go_assert(saw_errors()); return Expression::make_error(loc); } Temporary_statement* temp; Type* left_type = this->left_->type(); bool is_shift_op = (this->op_ == OPERATOR_LSHIFT || this->op_ == OPERATOR_RSHIFT); bool is_idiv_op = ((this->op_ == OPERATOR_DIV && left_type->integer_type() != NULL) || this->op_ == OPERATOR_MOD); bool is_string_op = (left_type->is_string_type() && this->right_->type()->is_string_type()); if (is_string_op) { // Mark string([]byte) operands to reuse the backing store. // String comparison does not keep the reference, so it is safe. Type_conversion_expression* lce = this->left_->conversion_expression(); if (lce != NULL && lce->expr()->type()->is_slice_type()) lce->set_no_copy(true); Type_conversion_expression* rce = this->right_->conversion_expression(); if (rce != NULL && rce->expr()->type()->is_slice_type()) rce->set_no_copy(true); } if (is_shift_op || (is_idiv_op && (gogo->check_divide_by_zero() || gogo->check_divide_overflow())) || is_string_op) { if (!this->left_->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, this->left_, loc); inserter->insert(temp); this->left_ = Expression::make_temporary_reference(temp, loc); } if (!this->right_->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, this->right_, loc); this->right_ = Expression::make_temporary_reference(temp, loc); inserter->insert(temp); } } return this; } // Return the address of EXPR, cast to unsafe.Pointer. Expression* Binary_expression::operand_address(Statement_inserter* inserter, Expression* expr) { Location loc = this->location(); if (!expr->is_addressable()) { Temporary_statement* temp = Statement::make_temporary(expr->type(), NULL, loc); inserter->insert(temp); expr = Expression::make_set_and_use_temporary(temp, expr, loc); } expr = Expression::make_unary(OPERATOR_AND, expr, loc); static_cast(expr)->set_does_not_escape(); Type* void_type = Type::make_void_type(); Type* unsafe_pointer_type = Type::make_pointer_type(void_type); return Expression::make_cast(unsafe_pointer_type, expr, loc); } // Return the numeric constant value, if it has one. bool Binary_expression::do_numeric_constant_value(Numeric_constant* nc) const { Numeric_constant left_nc; if (!this->left_->numeric_constant_value(&left_nc)) return false; Numeric_constant right_nc; if (!this->right_->numeric_constant_value(&right_nc)) return false; bool issued_error; return Binary_expression::eval_constant(this->op_, &left_nc, &right_nc, this->location(), nc, &issued_error); } // Return the boolean constant value, if it has one. bool Binary_expression::do_boolean_constant_value(bool* val) const { bool is_comparison = false; switch (this->op_) { case OPERATOR_EQEQ: case OPERATOR_NOTEQ: case OPERATOR_LT: case OPERATOR_LE: case OPERATOR_GT: case OPERATOR_GE: is_comparison = true; break; case OPERATOR_ANDAND: case OPERATOR_OROR: break; default: return false; } Numeric_constant left_nc, right_nc; if (is_comparison && this->left_->numeric_constant_value(&left_nc) && this->right_->numeric_constant_value(&right_nc)) return Binary_expression::compare_constant(this->op_, &left_nc, &right_nc, this->location(), val); std::string left_str, right_str; if (is_comparison && this->left_->string_constant_value(&left_str) && this->right_->string_constant_value(&right_str)) { *val = Binary_expression::cmp_to_bool(this->op_, left_str.compare(right_str)); return true; } bool left_bval; if (this->left_->boolean_constant_value(&left_bval)) { if (this->op_ == OPERATOR_ANDAND && !left_bval) { *val = false; return true; } else if (this->op_ == OPERATOR_OROR && left_bval) { *val = true; return true; } bool right_bval; if (this->right_->boolean_constant_value(&right_bval)) { switch (this->op_) { case OPERATOR_EQEQ: *val = (left_bval == right_bval); return true; case OPERATOR_NOTEQ: *val = (left_bval != right_bval); return true; case OPERATOR_ANDAND: case OPERATOR_OROR: *val = right_bval; return true; default: go_unreachable(); } } } return false; } // Note that the value is being discarded. bool Binary_expression::do_discarding_value() { if (this->op_ == OPERATOR_OROR || this->op_ == OPERATOR_ANDAND) return this->right_->discarding_value(); else { this->unused_value_error(); return false; } } // Get type. Type* Binary_expression::do_type() { if (this->classification() == EXPRESSION_ERROR) return Type::make_error_type(); switch (this->op_) { case OPERATOR_EQEQ: case OPERATOR_NOTEQ: case OPERATOR_LT: case OPERATOR_LE: case OPERATOR_GT: case OPERATOR_GE: if (this->type_ == NULL) this->type_ = Type::make_boolean_type(); return this->type_; case OPERATOR_PLUS: case OPERATOR_MINUS: case OPERATOR_OR: case OPERATOR_XOR: case OPERATOR_MULT: case OPERATOR_DIV: case OPERATOR_MOD: case OPERATOR_AND: case OPERATOR_BITCLEAR: case OPERATOR_OROR: case OPERATOR_ANDAND: { Type* type; if (!Binary_expression::operation_type(this->op_, this->left_->type(), this->right_->type(), &type)) return Type::make_error_type(); return type; } case OPERATOR_LSHIFT: case OPERATOR_RSHIFT: return this->left_->type(); default: go_unreachable(); } } // Set type for a binary expression. void Binary_expression::do_determine_type(const Type_context* context) { Type* tleft = this->left_->type(); Type* tright = this->right_->type(); // Both sides should have the same type, except for the shift // operations. For a comparison, we should ignore the incoming // type. bool is_shift_op = (this->op_ == OPERATOR_LSHIFT || this->op_ == OPERATOR_RSHIFT); bool is_comparison = (this->op_ == OPERATOR_EQEQ || this->op_ == OPERATOR_NOTEQ || this->op_ == OPERATOR_LT || this->op_ == OPERATOR_LE || this->op_ == OPERATOR_GT || this->op_ == OPERATOR_GE); // For constant expressions, the context of the result is not useful in // determining the types of the operands. It is only legal to use abstract // boolean, numeric, and string constants as operands where it is legal to // use non-abstract boolean, numeric, and string constants, respectively. // Any issues with the operation will be resolved in the check_types pass. bool is_constant_expr = (this->left_->is_constant() && this->right_->is_constant()); Type_context subcontext(*context); if (is_constant_expr && !is_shift_op) { subcontext.type = NULL; subcontext.may_be_abstract = true; } else if (is_comparison) { // In a comparison, the context does not determine the types of // the operands. subcontext.type = NULL; } // Set the context for the left hand operand. if (is_shift_op) { // The right hand operand of a shift plays no role in // determining the type of the left hand operand. } else if (!tleft->is_abstract()) subcontext.type = tleft; else if (!tright->is_abstract()) subcontext.type = tright; else if (subcontext.type == NULL) { if ((tleft->integer_type() != NULL && tright->integer_type() != NULL) || (tleft->float_type() != NULL && tright->float_type() != NULL) || (tleft->complex_type() != NULL && tright->complex_type() != NULL) || (tleft->is_boolean_type() && tright->is_boolean_type())) { // Both sides have an abstract integer, abstract float, // abstract complex, or abstract boolean type. Just let // CONTEXT determine whether they may remain abstract or not. } else if (tleft->complex_type() != NULL) subcontext.type = tleft; else if (tright->complex_type() != NULL) subcontext.type = tright; else if (tleft->float_type() != NULL) subcontext.type = tleft; else if (tright->float_type() != NULL) subcontext.type = tright; else subcontext.type = tleft; if (subcontext.type != NULL && !context->may_be_abstract) subcontext.type = subcontext.type->make_non_abstract_type(); } this->left_->determine_type(&subcontext); if (is_shift_op) { // We may have inherited an unusable type for the shift operand. // Give a useful error if that happened. if (tleft->is_abstract() && subcontext.type != NULL && !subcontext.may_be_abstract && subcontext.type->interface_type() == NULL && subcontext.type->integer_type() == NULL) this->report_error(("invalid context-determined non-integer type " "for left operand of shift")); // The context for the right hand operand is the same as for the // left hand operand, except for a shift operator. subcontext.type = Type::lookup_integer_type("uint"); subcontext.may_be_abstract = false; } this->right_->determine_type(&subcontext); if (is_comparison) { if (this->type_ != NULL && !this->type_->is_abstract()) ; else if (context->type != NULL && context->type->is_boolean_type()) this->type_ = context->type; else if (!context->may_be_abstract) this->type_ = Type::lookup_bool_type(); } } // Report an error if the binary operator OP does not support TYPE. // OTYPE is the type of the other operand. Return whether the // operation is OK. This should not be used for shift. bool Binary_expression::check_operator_type(Operator op, Type* type, Type* otype, Location location) { switch (op) { case OPERATOR_OROR: case OPERATOR_ANDAND: if (!type->is_boolean_type() || !otype->is_boolean_type()) { go_error_at(location, "expected boolean type"); return false; } break; case OPERATOR_EQEQ: case OPERATOR_NOTEQ: { std::string reason; if (!Type::are_compatible_for_comparison(true, type, otype, &reason)) { go_error_at(location, "%s", reason.c_str()); return false; } } break; case OPERATOR_LT: case OPERATOR_LE: case OPERATOR_GT: case OPERATOR_GE: { std::string reason; if (!Type::are_compatible_for_comparison(false, type, otype, &reason)) { go_error_at(location, "%s", reason.c_str()); return false; } } break; case OPERATOR_PLUS: case OPERATOR_PLUSEQ: if ((!type->is_numeric_type() && !type->is_string_type()) || (!otype->is_numeric_type() && !otype->is_string_type())) { go_error_at(location, "expected integer, floating, complex, or string type"); return false; } break; case OPERATOR_MINUS: case OPERATOR_MINUSEQ: case OPERATOR_MULT: case OPERATOR_MULTEQ: case OPERATOR_DIV: case OPERATOR_DIVEQ: if (!type->is_numeric_type() || !otype->is_numeric_type()) { go_error_at(location, "expected integer, floating, or complex type"); return false; } break; case OPERATOR_MOD: case OPERATOR_MODEQ: case OPERATOR_OR: case OPERATOR_OREQ: case OPERATOR_AND: case OPERATOR_ANDEQ: case OPERATOR_XOR: case OPERATOR_XOREQ: case OPERATOR_BITCLEAR: case OPERATOR_BITCLEAREQ: if (type->integer_type() == NULL || otype->integer_type() == NULL) { go_error_at(location, "expected integer type"); return false; } break; default: go_unreachable(); } return true; } // Check types. void Binary_expression::do_check_types(Gogo*) { if (this->classification() == EXPRESSION_ERROR) return; Type* left_type = this->left_->type(); Type* right_type = this->right_->type(); if (left_type->is_error() || right_type->is_error()) { this->set_is_error(); return; } if (this->op_ == OPERATOR_EQEQ || this->op_ == OPERATOR_NOTEQ || this->op_ == OPERATOR_LT || this->op_ == OPERATOR_LE || this->op_ == OPERATOR_GT || this->op_ == OPERATOR_GE) { if (left_type->is_nil_type() && right_type->is_nil_type()) { this->report_error(_("invalid comparison of nil with nil")); return; } if (!Type::are_assignable(left_type, right_type, NULL) && !Type::are_assignable(right_type, left_type, NULL)) { this->report_error(_("incompatible types in binary expression")); return; } if (!Binary_expression::check_operator_type(this->op_, left_type, right_type, this->location()) || !Binary_expression::check_operator_type(this->op_, right_type, left_type, this->location())) { this->set_is_error(); return; } } else if (this->op_ != OPERATOR_LSHIFT && this->op_ != OPERATOR_RSHIFT) { if (!Type::are_compatible_for_binop(left_type, right_type)) { this->report_error(_("incompatible types in binary expression")); return; } if (!Binary_expression::check_operator_type(this->op_, left_type, right_type, this->location())) { this->set_is_error(); return; } if (this->op_ == OPERATOR_DIV || this->op_ == OPERATOR_MOD) { // Division by a zero integer constant is an error. Numeric_constant rconst; unsigned long rval; if (left_type->integer_type() != NULL && this->right_->numeric_constant_value(&rconst) && rconst.to_unsigned_long(&rval) == Numeric_constant::NC_UL_VALID && rval == 0) { this->report_error(_("integer division by zero")); return; } } } else { if (left_type->integer_type() == NULL) this->report_error(_("shift of non-integer operand")); if (right_type->is_string_type()) this->report_error(_("shift count not integer")); else if (!right_type->is_abstract() && right_type->integer_type() == NULL) this->report_error(_("shift count not integer")); else { Numeric_constant nc; if (this->right_->numeric_constant_value(&nc)) { mpz_t val; if (!nc.to_int(&val)) this->report_error(_("shift count not integer")); else { if (mpz_sgn(val) < 0) { this->report_error(_("negative shift count")); Location rloc = this->right_->location(); this->right_ = Expression::make_integer_ul(0, right_type, rloc); } mpz_clear(val); } } } } } // Get the backend representation for a binary expression. Bexpression* Binary_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Location loc = this->location(); Type* left_type = this->left_->type(); Type* right_type = this->right_->type(); bool use_left_type = true; bool is_shift_op = false; bool is_idiv_op = false; switch (this->op_) { case OPERATOR_EQEQ: case OPERATOR_NOTEQ: case OPERATOR_LT: case OPERATOR_LE: case OPERATOR_GT: case OPERATOR_GE: return Expression::comparison(context, this->type_, this->op_, this->left_, this->right_, loc); case OPERATOR_OROR: case OPERATOR_ANDAND: use_left_type = false; break; case OPERATOR_PLUS: case OPERATOR_MINUS: case OPERATOR_OR: case OPERATOR_XOR: case OPERATOR_MULT: break; case OPERATOR_DIV: if (left_type->float_type() != NULL || left_type->complex_type() != NULL) break; // Fall through. case OPERATOR_MOD: is_idiv_op = true; break; case OPERATOR_LSHIFT: case OPERATOR_RSHIFT: is_shift_op = true; break; case OPERATOR_BITCLEAR: this->right_ = Expression::make_unary(OPERATOR_XOR, this->right_, loc); case OPERATOR_AND: break; default: go_unreachable(); } // The only binary operation for string is +, and that should have // been converted to a String_concat_expression in do_lower. go_assert(!left_type->is_string_type()); Bexpression* left = this->left_->get_backend(context); Bexpression* right = this->right_->get_backend(context); Type* type = use_left_type ? left_type : right_type; Btype* btype = type->get_backend(gogo); Bexpression* ret = gogo->backend()->binary_expression(this->op_, left, right, loc); ret = gogo->backend()->convert_expression(btype, ret, loc); // Initialize overflow constants. Bexpression* overflow; mpz_t zero; mpz_init_set_ui(zero, 0UL); mpz_t one; mpz_init_set_ui(one, 1UL); mpz_t neg_one; mpz_init_set_si(neg_one, -1); Btype* left_btype = left_type->get_backend(gogo); Btype* right_btype = right_type->get_backend(gogo); // In Go, a shift larger than the size of the type is well-defined. // This is not true in C, so we need to insert a conditional. // We also need to check for a negative shift count. if (is_shift_op) { go_assert(left_type->integer_type() != NULL); go_assert(right_type->integer_type() != NULL); int bits = left_type->integer_type()->bits(); Numeric_constant nc; unsigned long ul; if (!this->right_->numeric_constant_value(&nc) || nc.to_unsigned_long(&ul) != Numeric_constant::NC_UL_VALID || ul >= static_cast(bits)) { mpz_t bitsval; mpz_init_set_ui(bitsval, bits); Bexpression* bits_expr = gogo->backend()->integer_constant_expression(right_btype, bitsval); Bexpression* compare = gogo->backend()->binary_expression(OPERATOR_LT, right, bits_expr, loc); Bexpression* zero_expr = gogo->backend()->integer_constant_expression(left_btype, zero); overflow = zero_expr; Bfunction* bfn = context->function()->func_value()->get_decl(); if (this->op_ == OPERATOR_RSHIFT && !left_type->integer_type()->is_unsigned()) { Bexpression* neg_expr = gogo->backend()->binary_expression(OPERATOR_LT, left, zero_expr, loc); Bexpression* neg_one_expr = gogo->backend()->integer_constant_expression(left_btype, neg_one); overflow = gogo->backend()->conditional_expression(bfn, btype, neg_expr, neg_one_expr, zero_expr, loc); } ret = gogo->backend()->conditional_expression(bfn, btype, compare, ret, overflow, loc); mpz_clear(bitsval); } if (!right_type->integer_type()->is_unsigned() && (!this->right_->numeric_constant_value(&nc) || nc.to_unsigned_long(&ul) != Numeric_constant::NC_UL_VALID)) { Bexpression* zero_expr = gogo->backend()->integer_constant_expression(right_btype, zero); Bexpression* compare = gogo->backend()->binary_expression(OPERATOR_LT, right, zero_expr, loc); Expression* crash = Runtime::make_call(Runtime::PANIC_SHIFT, loc, 0); Bexpression* bcrash = crash->get_backend(context); Bfunction* bfn = context->function()->func_value()->get_decl(); ret = gogo->backend()->conditional_expression(bfn, btype, compare, bcrash, ret, loc); } } // Add checks for division by zero and division overflow as needed. if (is_idiv_op) { if (gogo->check_divide_by_zero()) { // right == 0 Bexpression* zero_expr = gogo->backend()->integer_constant_expression(right_btype, zero); Bexpression* check = gogo->backend()->binary_expression(OPERATOR_EQEQ, right, zero_expr, loc); Expression* crash = Runtime::make_call(Runtime::PANIC_DIVIDE, loc, 0); Bexpression* bcrash = crash->get_backend(context); // right == 0 ? (panicdivide(), 0) : ret Bfunction* bfn = context->function()->func_value()->get_decl(); ret = gogo->backend()->conditional_expression(bfn, btype, check, bcrash, ret, loc); } if (gogo->check_divide_overflow()) { // right == -1 // FIXME: It would be nice to say that this test is expected // to return false. Bexpression* neg_one_expr = gogo->backend()->integer_constant_expression(right_btype, neg_one); Bexpression* check = gogo->backend()->binary_expression(OPERATOR_EQEQ, right, neg_one_expr, loc); Bexpression* zero_expr = gogo->backend()->integer_constant_expression(btype, zero); Bexpression* one_expr = gogo->backend()->integer_constant_expression(btype, one); Bfunction* bfn = context->function()->func_value()->get_decl(); if (type->integer_type()->is_unsigned()) { // An unsigned -1 is the largest possible number, so // dividing is always 1 or 0. Bexpression* cmp = gogo->backend()->binary_expression(OPERATOR_EQEQ, left, right, loc); if (this->op_ == OPERATOR_DIV) overflow = gogo->backend()->conditional_expression(bfn, btype, cmp, one_expr, zero_expr, loc); else overflow = gogo->backend()->conditional_expression(bfn, btype, cmp, zero_expr, left, loc); } else { // Computing left / -1 is the same as computing - left, // which does not overflow since Go sets -fwrapv. if (this->op_ == OPERATOR_DIV) { Expression* negate_expr = Expression::make_unary(OPERATOR_MINUS, this->left_, loc); overflow = negate_expr->get_backend(context); } else overflow = zero_expr; } overflow = gogo->backend()->convert_expression(btype, overflow, loc); // right == -1 ? - left : ret ret = gogo->backend()->conditional_expression(bfn, btype, check, overflow, ret, loc); } } mpz_clear(zero); mpz_clear(one); mpz_clear(neg_one); return ret; } // Export a binary expression. void Binary_expression::do_export(Export_function_body* efb) const { efb->write_c_string("("); this->left_->export_expression(efb); switch (this->op_) { case OPERATOR_OROR: efb->write_c_string(" || "); break; case OPERATOR_ANDAND: efb->write_c_string(" && "); break; case OPERATOR_EQEQ: efb->write_c_string(" == "); break; case OPERATOR_NOTEQ: efb->write_c_string(" != "); break; case OPERATOR_LT: efb->write_c_string(" < "); break; case OPERATOR_LE: efb->write_c_string(" <= "); break; case OPERATOR_GT: efb->write_c_string(" > "); break; case OPERATOR_GE: efb->write_c_string(" >= "); break; case OPERATOR_PLUS: efb->write_c_string(" + "); break; case OPERATOR_MINUS: efb->write_c_string(" - "); break; case OPERATOR_OR: efb->write_c_string(" | "); break; case OPERATOR_XOR: efb->write_c_string(" ^ "); break; case OPERATOR_MULT: efb->write_c_string(" * "); break; case OPERATOR_DIV: efb->write_c_string(" / "); break; case OPERATOR_MOD: efb->write_c_string(" % "); break; case OPERATOR_LSHIFT: efb->write_c_string(" << "); break; case OPERATOR_RSHIFT: efb->write_c_string(" >> "); break; case OPERATOR_AND: efb->write_c_string(" & "); break; case OPERATOR_BITCLEAR: efb->write_c_string(" &^ "); break; default: go_unreachable(); } this->right_->export_expression(efb); efb->write_c_string(")"); } // Import a binary expression. Expression* Binary_expression::do_import(Import_expression* imp, Location loc) { imp->require_c_string("("); Expression* left = Expression::import_expression(imp, loc); Operator op; if (imp->match_c_string(" || ")) { op = OPERATOR_OROR; imp->advance(4); } else if (imp->match_c_string(" && ")) { op = OPERATOR_ANDAND; imp->advance(4); } else if (imp->match_c_string(" == ")) { op = OPERATOR_EQEQ; imp->advance(4); } else if (imp->match_c_string(" != ")) { op = OPERATOR_NOTEQ; imp->advance(4); } else if (imp->match_c_string(" < ")) { op = OPERATOR_LT; imp->advance(3); } else if (imp->match_c_string(" <= ")) { op = OPERATOR_LE; imp->advance(4); } else if (imp->match_c_string(" > ")) { op = OPERATOR_GT; imp->advance(3); } else if (imp->match_c_string(" >= ")) { op = OPERATOR_GE; imp->advance(4); } else if (imp->match_c_string(" + ")) { op = OPERATOR_PLUS; imp->advance(3); } else if (imp->match_c_string(" - ")) { op = OPERATOR_MINUS; imp->advance(3); } else if (imp->match_c_string(" | ")) { op = OPERATOR_OR; imp->advance(3); } else if (imp->match_c_string(" ^ ")) { op = OPERATOR_XOR; imp->advance(3); } else if (imp->match_c_string(" * ")) { op = OPERATOR_MULT; imp->advance(3); } else if (imp->match_c_string(" / ")) { op = OPERATOR_DIV; imp->advance(3); } else if (imp->match_c_string(" % ")) { op = OPERATOR_MOD; imp->advance(3); } else if (imp->match_c_string(" << ")) { op = OPERATOR_LSHIFT; imp->advance(4); } else if (imp->match_c_string(" >> ")) { op = OPERATOR_RSHIFT; imp->advance(4); } else if (imp->match_c_string(" & ")) { op = OPERATOR_AND; imp->advance(3); } else if (imp->match_c_string(" &^ ")) { op = OPERATOR_BITCLEAR; imp->advance(4); } else if (imp->match_c_string(")")) { // Not a binary operator after all. imp->advance(1); return left; } else { go_error_at(imp->location(), "unrecognized binary operator"); return Expression::make_error(loc); } Expression* right = Expression::import_expression(imp, loc); imp->require_c_string(")"); return Expression::make_binary(op, left, right, loc); } // Dump ast representation of a binary expression. void Binary_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->left_); ast_dump_context->ostream() << " "; ast_dump_context->dump_operator(this->op_); ast_dump_context->ostream() << " "; ast_dump_context->dump_expression(this->right_); ast_dump_context->ostream() << ") "; } // Make a binary expression. Expression* Expression::make_binary(Operator op, Expression* left, Expression* right, Location location) { return new Binary_expression(op, left, right, location); } // Implement a comparison. Bexpression* Expression::comparison(Translate_context* context, Type* result_type, Operator op, Expression* left, Expression* right, Location location) { Type* left_type = left->type(); Type* right_type = right->type(); Expression* zexpr = Expression::make_integer_ul(0, NULL, location); if (left_type->is_string_type() && right_type->is_string_type()) { go_assert(left->is_multi_eval_safe()); go_assert(right->is_multi_eval_safe()); if (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ) { // (l.len == r.len // ? (l.ptr == r.ptr ? true : memcmp(l.ptr, r.ptr, r.len) == 0) // : false) Expression* llen = Expression::make_string_info(left, STRING_INFO_LENGTH, location); Expression* rlen = Expression::make_string_info(right, STRING_INFO_LENGTH, location); Expression* leneq = Expression::make_binary(OPERATOR_EQEQ, llen, rlen, location); Expression* lptr = Expression::make_string_info(left->copy(), STRING_INFO_DATA, location); Expression* rptr = Expression::make_string_info(right->copy(), STRING_INFO_DATA, location); Expression* ptreq = Expression::make_binary(OPERATOR_EQEQ, lptr, rptr, location); Expression* btrue = Expression::make_boolean(true, location); Expression* call = Runtime::make_call(Runtime::MEMCMP, location, 3, lptr->copy(), rptr->copy(), rlen->copy()); Type* int32_type = Type::lookup_integer_type("int32"); Expression* zero = Expression::make_integer_ul(0, int32_type, location); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, call, zero, location); Expression* cond = Expression::make_conditional(ptreq, btrue, cmp, location); Expression* bfalse = Expression::make_boolean(false, location); left = Expression::make_conditional(leneq, cond, bfalse, location); right = Expression::make_boolean(true, location); } else { left = Runtime::make_call(Runtime::CMPSTRING, location, 2, left, right); right = zexpr; } } else if ((left_type->interface_type() != NULL && right_type->interface_type() == NULL && !right_type->is_nil_type()) || (left_type->interface_type() == NULL && !left_type->is_nil_type() && right_type->interface_type() != NULL)) { // Comparing an interface value to a non-interface value. if (left_type->interface_type() == NULL) { std::swap(left_type, right_type); std::swap(left, right); } // The right operand is not an interface. We need to take its // address if it is not a direct interface type. Expression* pointer_arg = NULL; if (right_type->is_direct_iface_type()) pointer_arg = Expression::unpack_direct_iface(right, location); else { go_assert(right->is_addressable()); pointer_arg = Expression::make_unary(OPERATOR_AND, right, location); } Expression* descriptor = Expression::make_type_descriptor(right_type, location); left = Runtime::make_call((left_type->interface_type()->is_empty() ? Runtime::EFACEVALEQ : Runtime::IFACEVALEQ), location, 3, left, descriptor, pointer_arg); go_assert(op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ); right = Expression::make_boolean(true, location); } else if (left_type->interface_type() != NULL && right_type->interface_type() != NULL) { Runtime::Function compare_function; if (left_type->interface_type()->is_empty() && right_type->interface_type()->is_empty()) compare_function = Runtime::EFACEEQ; else if (!left_type->interface_type()->is_empty() && !right_type->interface_type()->is_empty()) compare_function = Runtime::IFACEEQ; else { if (left_type->interface_type()->is_empty()) { std::swap(left_type, right_type); std::swap(left, right); } go_assert(!left_type->interface_type()->is_empty()); go_assert(right_type->interface_type()->is_empty()); compare_function = Runtime::IFACEEFACEEQ; } left = Runtime::make_call(compare_function, location, 2, left, right); go_assert(op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ); right = Expression::make_boolean(true, location); } if (left_type->is_nil_type() && (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ)) { std::swap(left_type, right_type); std::swap(left, right); } if (right_type->is_nil_type()) { right = Expression::make_nil(location); if (left_type->array_type() != NULL && left_type->array_type()->length() == NULL) { Array_type* at = left_type->array_type(); left = at->get_value_pointer(context->gogo(), left); } else if (left_type->interface_type() != NULL) { // An interface is nil if the first field is nil. left = Expression::make_field_reference(left, 0, location); } } Bexpression* left_bexpr = left->get_backend(context); Bexpression* right_bexpr = right->get_backend(context); Gogo* gogo = context->gogo(); Bexpression* ret = gogo->backend()->binary_expression(op, left_bexpr, right_bexpr, location); if (result_type != NULL) ret = gogo->backend()->convert_expression(result_type->get_backend(gogo), ret, location); return ret; } // Class String_concat_expression. bool String_concat_expression::do_is_constant() const { for (Expression_list::const_iterator pe = this->exprs_->begin(); pe != this->exprs_->end(); ++pe) { if (!(*pe)->is_constant()) return false; } return true; } bool String_concat_expression::do_is_zero_value() const { for (Expression_list::const_iterator pe = this->exprs_->begin(); pe != this->exprs_->end(); ++pe) { if (!(*pe)->is_zero_value()) return false; } return true; } bool String_concat_expression::do_is_static_initializer() const { for (Expression_list::const_iterator pe = this->exprs_->begin(); pe != this->exprs_->end(); ++pe) { if (!(*pe)->is_static_initializer()) return false; } return true; } Type* String_concat_expression::do_type() { Type* t = this->exprs_->front()->type(); Expression_list::iterator pe = this->exprs_->begin(); ++pe; for (; pe != this->exprs_->end(); ++pe) { Type* t1; if (!Binary_expression::operation_type(OPERATOR_PLUS, t, (*pe)->type(), &t1)) return Type::make_error_type(); t = t1; } return t; } void String_concat_expression::do_determine_type(const Type_context* context) { Type_context subcontext(*context); for (Expression_list::iterator pe = this->exprs_->begin(); pe != this->exprs_->end(); ++pe) { Type* t = (*pe)->type(); if (!t->is_abstract()) { subcontext.type = t; break; } } if (subcontext.type == NULL) subcontext.type = this->exprs_->front()->type(); for (Expression_list::iterator pe = this->exprs_->begin(); pe != this->exprs_->end(); ++pe) (*pe)->determine_type(&subcontext); } void String_concat_expression::do_check_types(Gogo*) { if (this->is_error_expression()) return; Type* t = this->exprs_->front()->type(); if (t->is_error()) { this->set_is_error(); return; } Expression_list::iterator pe = this->exprs_->begin(); ++pe; for (; pe != this->exprs_->end(); ++pe) { Type* t1 = (*pe)->type(); if (!Type::are_compatible_for_binop(t, t1)) { this->report_error("incompatible types in binary expression"); return; } if (!Binary_expression::check_operator_type(OPERATOR_PLUS, t, t1, this->location())) { this->set_is_error(); return; } } } Expression* String_concat_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { if (this->is_error_expression()) return this; Location loc = this->location(); Type* type = this->type(); // Mark string([]byte) operands to reuse the backing store. // runtime.concatstrings does not keep the reference. // // Note: in the gc runtime, if all but one inputs are empty, // concatstrings returns the only nonempty input without copy. // So it is not safe to reuse the backing store if it is a // string([]byte) conversion. So the gc compiler does the // no-copy optimization only when there is at least one // constant nonempty input. Currently the gccgo runtime // doesn't do this, so we don't do the check. for (Expression_list::iterator p = this->exprs_->begin(); p != this->exprs_->end(); ++p) { Type_conversion_expression* tce = (*p)->conversion_expression(); if (tce != NULL) tce->set_no_copy(true); } Expression* buf = NULL; Node* n = Node::make_node(this); if ((n->encoding() & ESCAPE_MASK) == Node::ESCAPE_NONE) { size_t size = 0; for (Expression_list::iterator p = this->exprs_->begin(); p != this->exprs_->end(); ++p) { std::string s; if ((*p)->string_constant_value(&s)) size += s.length(); } // Make a buffer on stack if the result does not escape. // But don't do this if we know it won't fit. if (size < (size_t)tmp_string_buf_size) { Type* byte_type = Type::lookup_integer_type("uint8"); Expression* buflen = Expression::make_integer_ul(tmp_string_buf_size, NULL, loc); Expression::make_integer_ul(tmp_string_buf_size, NULL, loc); Type* array_type = Type::make_array_type(byte_type, buflen); buf = Expression::make_allocation(array_type, loc); buf->allocation_expression()->set_allocate_on_stack(); buf->allocation_expression()->set_no_zero(); } } if (buf == NULL) buf = Expression::make_nil(loc); go_assert(this->exprs_->size() > 1); Expression* len = Expression::make_integer_ul(this->exprs_->size(), NULL, loc); Array_type* array_type = Type::make_array_type(type, len); array_type->set_is_array_incomparable(); Expression* array = Expression::make_array_composite_literal(array_type, this->exprs_, loc); Temporary_statement* ts = Statement::make_temporary(array_type, array, loc); inserter->insert(ts); Expression* ref = Expression::make_temporary_reference(ts, loc); ref = Expression::make_unary(OPERATOR_AND, ref, loc); Expression* call = Runtime::make_call(Runtime::CONCATSTRINGS, loc, 3, buf, ref, len->copy()); return Expression::make_cast(type, call, loc); } void String_concat_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "concat("; ast_dump_context->dump_expression_list(this->exprs_, false); ast_dump_context->ostream() << ")"; } Expression* Expression::make_string_concat(Expression_list* exprs) { return new String_concat_expression(exprs); } // Class Bound_method_expression. // Traversal. int Bound_method_expression::do_traverse(Traverse* traverse) { return Expression::traverse(&this->expr_, traverse); } // Return the type of a bound method expression. The type of this // object is simply the type of the method with no receiver. Type* Bound_method_expression::do_type() { Named_object* fn = this->method_->named_object(); Function_type* fntype; if (fn->is_function()) fntype = fn->func_value()->type(); else if (fn->is_function_declaration()) fntype = fn->func_declaration_value()->type(); else return Type::make_error_type(); return fntype->copy_without_receiver(); } // Determine the types of a method expression. void Bound_method_expression::do_determine_type(const Type_context*) { Named_object* fn = this->method_->named_object(); Function_type* fntype; if (fn->is_function()) fntype = fn->func_value()->type(); else if (fn->is_function_declaration()) fntype = fn->func_declaration_value()->type(); else fntype = NULL; if (fntype == NULL || !fntype->is_method()) this->expr_->determine_type_no_context(); else { Type_context subcontext(fntype->receiver()->type(), false); this->expr_->determine_type(&subcontext); } } // Check the types of a method expression. void Bound_method_expression::do_check_types(Gogo*) { Named_object* fn = this->method_->named_object(); if (!fn->is_function() && !fn->is_function_declaration()) { this->report_error(_("object is not a method")); return; } Function_type* fntype; if (fn->is_function()) fntype = fn->func_value()->type(); else if (fn->is_function_declaration()) fntype = fn->func_declaration_value()->type(); else go_unreachable(); Type* rtype = fntype->receiver()->type()->deref(); Type* etype = (this->expr_type_ != NULL ? this->expr_type_ : this->expr_->type()); etype = etype->deref(); if (!Type::are_identical(rtype, etype, Type::COMPARE_TAGS, NULL)) this->report_error(_("method type does not match object type")); } // If a bound method expression is not simply called, then it is // represented as a closure. The closure will hold a single variable, // the receiver to pass to the method. The function will be a simple // thunk that pulls that value from the closure and calls the method // with the remaining arguments. // // Because method values are not common, we don't build all thunks for // every methods, but instead only build them as we need them. In // particular, we even build them on demand for methods defined in // other packages. Bound_method_expression::Method_value_thunks Bound_method_expression::method_value_thunks; // Find or create the thunk for FN. Named_object* Bound_method_expression::create_thunk(Gogo* gogo, const Method* method, Named_object* fn) { std::pair val(fn, NULL); std::pair ins = Bound_method_expression::method_value_thunks.insert(val); if (!ins.second) { // We have seen this method before. go_assert(ins.first->second != NULL); return ins.first->second; } Location loc = fn->location(); Function_type* orig_fntype; if (fn->is_function()) orig_fntype = fn->func_value()->type(); else if (fn->is_function_declaration()) orig_fntype = fn->func_declaration_value()->type(); else orig_fntype = NULL; if (orig_fntype == NULL || !orig_fntype->is_method()) { ins.first->second = Named_object::make_erroneous_name(gogo->thunk_name()); return ins.first->second; } Struct_field_list* sfl = new Struct_field_list(); // The type here is wrong--it should be the C function type. But it // doesn't really matter. Type* vt = Type::make_pointer_type(Type::make_void_type()); sfl->push_back(Struct_field(Typed_identifier("fn", vt, loc))); sfl->push_back(Struct_field(Typed_identifier("val", orig_fntype->receiver()->type(), loc))); Struct_type* st = Type::make_struct_type(sfl, loc); st->set_is_struct_incomparable(); Type* closure_type = Type::make_pointer_type(st); Function_type* new_fntype = orig_fntype->copy_with_names(); std::string thunk_name = gogo->thunk_name(); Named_object* new_no = gogo->start_function(thunk_name, new_fntype, false, loc); Variable* cvar = new Variable(closure_type, NULL, false, false, false, loc); cvar->set_is_used(); cvar->set_is_closure(); Named_object* cp = Named_object::make_variable("$closure" + thunk_name, NULL, cvar); new_no->func_value()->set_closure_var(cp); gogo->start_block(loc); // Field 0 of the closure is the function code pointer, field 1 is // the value on which to invoke the method. Expression* arg = Expression::make_var_reference(cp, loc); arg = Expression::make_dereference(arg, NIL_CHECK_NOT_NEEDED, loc); arg = Expression::make_field_reference(arg, 1, loc); Expression* bme = Expression::make_bound_method(arg, method, fn, loc); const Typed_identifier_list* orig_params = orig_fntype->parameters(); Expression_list* args; if (orig_params == NULL || orig_params->empty()) args = NULL; else { const Typed_identifier_list* new_params = new_fntype->parameters(); args = new Expression_list(); for (Typed_identifier_list::const_iterator p = new_params->begin(); p != new_params->end(); ++p) { Named_object* p_no = gogo->lookup(p->name(), NULL); go_assert(p_no != NULL && p_no->is_variable() && p_no->var_value()->is_parameter()); args->push_back(Expression::make_var_reference(p_no, loc)); } } Call_expression* call = Expression::make_call(bme, args, orig_fntype->is_varargs(), loc); call->set_varargs_are_lowered(); Statement* s = Statement::make_return_from_call(call, loc); gogo->add_statement(s); Block* b = gogo->finish_block(loc); gogo->add_block(b, loc); // This is called after lowering but before determine_types. gogo->lower_block(new_no, b); gogo->finish_function(loc); ins.first->second = new_no; return new_no; } // Look up a thunk for FN. Named_object* Bound_method_expression::lookup_thunk(Named_object* fn) { Method_value_thunks::const_iterator p = Bound_method_expression::method_value_thunks.find(fn); if (p == Bound_method_expression::method_value_thunks.end()) return NULL; return p->second; } // Return an expression to check *REF for nil while dereferencing // according to FIELD_INDEXES. Update *REF to build up the field // reference. This is a static function so that we don't have to // worry about declaring Field_indexes in expressions.h. static Expression* bme_check_nil(const Method::Field_indexes* field_indexes, Location loc, Expression** ref) { if (field_indexes == NULL) return Expression::make_boolean(false, loc); Expression* cond = bme_check_nil(field_indexes->next, loc, ref); Struct_type* stype = (*ref)->type()->deref()->struct_type(); go_assert(stype != NULL && field_indexes->field_index < stype->field_count()); if ((*ref)->type()->struct_type() == NULL) { go_assert((*ref)->type()->points_to() != NULL); Expression* n = Expression::make_binary(OPERATOR_EQEQ, *ref, Expression::make_nil(loc), loc); cond = Expression::make_binary(OPERATOR_OROR, cond, n, loc); *ref = Expression::make_dereference(*ref, Expression::NIL_CHECK_DEFAULT, loc); go_assert((*ref)->type()->struct_type() == stype); } *ref = Expression::make_field_reference(*ref, field_indexes->field_index, loc); return cond; } // Flatten a method value into a struct with nil checks. We can't do // this in the lowering phase, because if the method value is called // directly we don't need a thunk. That case will have been handled // by Call_expression::do_lower, so if we get here then we do need a // thunk. Expression* Bound_method_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { Location loc = this->location(); Named_object* thunk = Bound_method_expression::lookup_thunk(this->function_); // The thunk should have been created during the // create_function_descriptors pass. if (thunk == NULL || thunk->is_erroneous()) { go_assert(saw_errors()); return Expression::make_error(loc); } // Force the expression into a variable. This is only necessary if // we are going to do nil checks below, but it's easy enough to // always do it. Expression* expr = this->expr_; if (!expr->is_multi_eval_safe()) { Temporary_statement* etemp = Statement::make_temporary(NULL, expr, loc); inserter->insert(etemp); expr = Expression::make_temporary_reference(etemp, loc); } // If the method expects a value, and we have a pointer, we need to // dereference the pointer. Named_object* fn = this->method_->named_object(); Function_type *fntype; if (fn->is_function()) fntype = fn->func_value()->type(); else if (fn->is_function_declaration()) fntype = fn->func_declaration_value()->type(); else go_unreachable(); Expression* val = expr; if (fntype->receiver()->type()->points_to() == NULL && val->type()->points_to() != NULL) val = Expression::make_dereference(val, NIL_CHECK_DEFAULT, loc); // Note that we are ignoring this->expr_type_ here. The thunk will // expect a closure whose second field has type this->expr_type_ (if // that is not NULL). We are going to pass it a closure whose // second field has type this->expr_->type(). Since // this->expr_type_ is only not-NULL for pointer types, we can get // away with this. Struct_field_list* fields = new Struct_field_list(); fields->push_back(Struct_field(Typed_identifier("fn", thunk->func_value()->type(), loc))); fields->push_back(Struct_field(Typed_identifier("val", val->type(), loc))); Struct_type* st = Type::make_struct_type(fields, loc); st->set_is_struct_incomparable(); Expression_list* vals = new Expression_list(); vals->push_back(Expression::make_func_code_reference(thunk, loc)); vals->push_back(val); Expression* ret = Expression::make_struct_composite_literal(st, vals, loc); ret = Expression::make_heap_expression(ret, loc); Node* node = Node::make_node(this); if ((node->encoding() & ESCAPE_MASK) == Node::ESCAPE_NONE) ret->heap_expression()->set_allocate_on_stack(); else if (gogo->compiling_runtime() && gogo->package_name() == "runtime" && !saw_errors()) go_error_at(loc, "%s escapes to heap, not allowed in runtime", node->ast_format(gogo).c_str()); // If necessary, check whether the expression or any embedded // pointers are nil. Expression* nil_check = NULL; if (this->method_->field_indexes() != NULL) { Expression* ref = expr; nil_check = bme_check_nil(this->method_->field_indexes(), loc, &ref); expr = ref; } if (this->method_->is_value_method() && expr->type()->points_to() != NULL) { Expression* n = Expression::make_binary(OPERATOR_EQEQ, expr, Expression::make_nil(loc), loc); if (nil_check == NULL) nil_check = n; else nil_check = Expression::make_binary(OPERATOR_OROR, nil_check, n, loc); } if (nil_check != NULL) { Expression* crash = Runtime::make_call(Runtime::PANIC_MEM, loc, 0); // Fix the type of the conditional expression by pretending to // evaluate to RET either way through the conditional. crash = Expression::make_compound(crash, ret, loc); ret = Expression::make_conditional(nil_check, crash, ret, loc); } // RET is a pointer to a struct, but we want a function type. ret = Expression::make_unsafe_cast(this->type(), ret, loc); return ret; } // Dump ast representation of a bound method expression. void Bound_method_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { if (this->expr_type_ != NULL) ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->expr_); if (this->expr_type_ != NULL) { ast_dump_context->ostream() << ":"; ast_dump_context->dump_type(this->expr_type_); ast_dump_context->ostream() << ")"; } ast_dump_context->ostream() << "." << this->function_->name(); } // Make a method expression. Bound_method_expression* Expression::make_bound_method(Expression* expr, const Method* method, Named_object* function, Location location) { return new Bound_method_expression(expr, method, function, location); } // Class Builtin_call_expression. This is used for a call to a // builtin function. Builtin_call_expression::Builtin_call_expression(Gogo* gogo, Expression* fn, Expression_list* args, bool is_varargs, Location location) : Call_expression(fn, args, is_varargs, location), gogo_(gogo), code_(BUILTIN_INVALID), seen_(false), recover_arg_is_set_(false) { Func_expression* fnexp = this->fn()->func_expression(); if (fnexp == NULL) { this->code_ = BUILTIN_INVALID; return; } const std::string& name(fnexp->named_object()->name()); if (name == "append") this->code_ = BUILTIN_APPEND; else if (name == "cap") this->code_ = BUILTIN_CAP; else if (name == "close") this->code_ = BUILTIN_CLOSE; else if (name == "complex") this->code_ = BUILTIN_COMPLEX; else if (name == "copy") this->code_ = BUILTIN_COPY; else if (name == "delete") this->code_ = BUILTIN_DELETE; else if (name == "imag") this->code_ = BUILTIN_IMAG; else if (name == "len") this->code_ = BUILTIN_LEN; else if (name == "make") this->code_ = BUILTIN_MAKE; else if (name == "new") this->code_ = BUILTIN_NEW; else if (name == "panic") this->code_ = BUILTIN_PANIC; else if (name == "print") this->code_ = BUILTIN_PRINT; else if (name == "println") this->code_ = BUILTIN_PRINTLN; else if (name == "real") this->code_ = BUILTIN_REAL; else if (name == "recover") this->code_ = BUILTIN_RECOVER; else if (name == "Add") this->code_ = BUILTIN_ADD; else if (name == "Alignof") this->code_ = BUILTIN_ALIGNOF; else if (name == "Offsetof") this->code_ = BUILTIN_OFFSETOF; else if (name == "Sizeof") this->code_ = BUILTIN_SIZEOF; else if (name == "Slice") this->code_ = BUILTIN_SLICE; else go_unreachable(); } // Return whether this is a call to recover. This is a virtual // function called from the parent class. bool Builtin_call_expression::do_is_recover_call() const { if (this->classification() == EXPRESSION_ERROR) return false; return this->code_ == BUILTIN_RECOVER; } // Set the argument for a call to recover. void Builtin_call_expression::do_set_recover_arg(Expression* arg) { const Expression_list* args = this->args(); go_assert(args == NULL || args->empty()); Expression_list* new_args = new Expression_list(); new_args->push_back(arg); this->set_args(new_args); this->recover_arg_is_set_ = true; } // Lower a builtin call expression. This turns new and make into // specific expressions. We also convert to a constant if we can. Expression* Builtin_call_expression::do_lower(Gogo*, Named_object* function, Statement_inserter* inserter, int) { if (this->is_error_expression()) return this; Location loc = this->location(); if (this->is_varargs() && this->code_ != BUILTIN_APPEND) { this->report_error(_("invalid use of %<...%> with builtin function")); return Expression::make_error(loc); } if (this->code_ == BUILTIN_OFFSETOF) { Expression* arg = this->one_arg(); if (arg->bound_method_expression() != NULL || arg->interface_field_reference_expression() != NULL) { this->report_error(_("invalid use of method value as argument " "of Offsetof")); return this; } Field_reference_expression* farg = arg->field_reference_expression(); while (farg != NULL) { if (!farg->implicit()) break; // When the selector refers to an embedded field, // it must not be reached through pointer indirections. if (farg->expr()->deref() != farg->expr()) { this->report_error(_("argument of Offsetof implies " "indirection of an embedded field")); return this; } // Go up until we reach the original base. farg = farg->expr()->field_reference_expression(); } } if (this->is_constant()) { Numeric_constant nc; if (this->numeric_constant_value(&nc)) return nc.expression(loc); } switch (this->code_) { default: break; case BUILTIN_NEW: { const Expression_list* args = this->args(); if (args == NULL || args->size() < 1) this->report_error(_("not enough arguments")); else if (args->size() > 1) this->report_error(_("too many arguments")); else { Expression* arg = args->front(); if (!arg->is_type_expression()) { go_error_at(arg->location(), "expected type"); this->set_is_error(); } else return Expression::make_allocation(arg->type(), loc); } } break; case BUILTIN_MAKE: return this->lower_make(inserter); case BUILTIN_RECOVER: if (function != NULL) function->func_value()->set_calls_recover(); else { // Calling recover outside of a function always returns the // nil empty interface. Type* eface = Type::make_empty_interface_type(loc); return Expression::make_cast(eface, Expression::make_nil(loc), loc); } break; case BUILTIN_DELETE: { const Expression_list* args = this->args(); if (args == NULL || args->size() < 2) this->report_error(_("not enough arguments")); else if (args->size() > 2) this->report_error(_("too many arguments")); else if (args->front()->type()->map_type() == NULL) this->report_error(_("argument 1 must be a map")); else { Type* key_type = args->front()->type()->map_type()->key_type(); Expression_list::iterator pa = this->args()->begin(); pa++; Type* arg_type = (*pa)->type(); std::string reason; if (!Type::are_assignable(key_type, arg_type, &reason)) { if (reason.empty()) go_error_at(loc, "argument 2 has incompatible type"); else go_error_at(loc, "argument 2 has incompatible type (%s)", reason.c_str()); this->set_is_error(); } else if (!Type::are_identical(key_type, arg_type, 0, NULL)) *pa = Expression::make_cast(key_type, *pa, loc); } } break; case BUILTIN_PRINT: case BUILTIN_PRINTLN: // Force all the arguments into temporary variables, so that we // don't try to evaluate something while holding the print lock. if (this->args() == NULL) break; for (Expression_list::iterator pa = this->args()->begin(); pa != this->args()->end(); ++pa) { if (!(*pa)->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, *pa, loc); inserter->insert(temp); *pa = Expression::make_temporary_reference(temp, loc); } } break; } return this; } // Flatten a builtin call expression. This turns the arguments of some // builtin calls into temporary expressions. Also expand copy and append // to runtime calls. Expression* Builtin_call_expression::do_flatten(Gogo* gogo, Named_object* function, Statement_inserter* inserter) { if (this->is_error_expression()) { go_assert(saw_errors()); return this; } Location loc = this->location(); switch (this->code_) { default: break; case BUILTIN_APPEND: return this->flatten_append(gogo, function, inserter, NULL, NULL); case BUILTIN_COPY: { Type* at = this->args()->front()->type(); for (Expression_list::iterator pa = this->args()->begin(); pa != this->args()->end(); ++pa) { if ((*pa)->is_error_expression()) { go_assert(saw_errors()); return Expression::make_error(loc); } if ((*pa)->is_nil_expression()) { Expression* nil = Expression::make_nil(loc); Expression* zero = Expression::make_integer_ul(0, NULL, loc); *pa = Expression::make_slice_value(at, nil, zero, zero, loc); } if (!(*pa)->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, *pa, loc); inserter->insert(temp); *pa = Expression::make_temporary_reference(temp, loc); } } // Lower to runtime call. const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 2); Expression* arg1 = args->front(); Expression* arg2 = args->back(); go_assert(arg1->is_multi_eval_safe()); go_assert(arg2->is_multi_eval_safe()); bool arg2_is_string = arg2->type()->is_string_type(); Expression* ret; Type* et = at->array_type()->element_type(); if (et->has_pointer()) { Expression* td = Expression::make_type_descriptor(et, loc); Expression* pd = Expression::make_slice_info(arg1, SLICE_INFO_VALUE_POINTER, loc); Expression* ld = Expression::make_slice_info(arg1, SLICE_INFO_LENGTH, loc); Expression* ps = Expression::make_slice_info(arg2, SLICE_INFO_VALUE_POINTER, loc); Expression* ls = Expression::make_slice_info(arg2, SLICE_INFO_LENGTH, loc); ret = Runtime::make_call(Runtime::TYPEDSLICECOPY, loc, 5, td, pd, ld, ps, ls); } else { Type* int_type = Type::lookup_integer_type("int"); Type* uintptr_type = Type::lookup_integer_type("uintptr"); // l1 = len(arg1) Named_object* lenfn = gogo->lookup_global("len"); Expression* lenref = Expression::make_func_reference(lenfn, NULL, loc); Expression_list* len_args = new Expression_list(); len_args->push_back(arg1->copy()); Expression* len1 = Expression::make_call(lenref, len_args, false, loc); gogo->lower_expression(function, inserter, &len1); gogo->flatten_expression(function, inserter, &len1); Temporary_statement* l1tmp = Statement::make_temporary(int_type, len1, loc); inserter->insert(l1tmp); // l2 = len(arg2) len_args = new Expression_list(); len_args->push_back(arg2->copy()); Expression* len2 = Expression::make_call(lenref, len_args, false, loc); gogo->lower_expression(function, inserter, &len2); gogo->flatten_expression(function, inserter, &len2); Temporary_statement* l2tmp = Statement::make_temporary(int_type, len2, loc); inserter->insert(l2tmp); // n = (l1 < l2 ? l1 : l2) Expression* l1ref = Expression::make_temporary_reference(l1tmp, loc); Expression* l2ref = Expression::make_temporary_reference(l2tmp, loc); Expression* cond = Expression::make_binary(OPERATOR_LT, l1ref, l2ref, loc); Expression* n = Expression::make_conditional(cond, l1ref->copy(), l2ref->copy(), loc); Temporary_statement* ntmp = Statement::make_temporary(NULL, n, loc); inserter->insert(ntmp); // sz = n * sizeof(elem_type) Expression* nref = Expression::make_temporary_reference(ntmp, loc); nref = Expression::make_cast(uintptr_type, nref, loc); Expression* sz = Expression::make_type_info(et, TYPE_INFO_SIZE); sz = Expression::make_binary(OPERATOR_MULT, sz, nref, loc); // memmove(arg1.ptr, arg2.ptr, sz) Expression* p1 = Expression::make_slice_info(arg1, SLICE_INFO_VALUE_POINTER, loc); Expression* p2 = (arg2_is_string ? Expression::make_string_info(arg2, STRING_INFO_DATA, loc) : Expression::make_slice_info(arg2, SLICE_INFO_VALUE_POINTER, loc)); Expression* call = Runtime::make_call(Runtime::BUILTIN_MEMMOVE, loc, 3, p1, p2, sz); // n is the return value of copy nref = Expression::make_temporary_reference(ntmp, loc); ret = Expression::make_compound(call, nref, loc); } return ret; } break; case BUILTIN_PANIC: for (Expression_list::iterator pa = this->args()->begin(); pa != this->args()->end(); ++pa) { if (!(*pa)->is_multi_eval_safe() && (*pa)->type()->interface_type() != NULL) { Temporary_statement* temp = Statement::make_temporary(NULL, *pa, loc); inserter->insert(temp); *pa = Expression::make_temporary_reference(temp, loc); } } break; case BUILTIN_LEN: case BUILTIN_CAP: { Expression_list::iterator pa = this->args()->begin(); if (!(*pa)->is_multi_eval_safe() && ((*pa)->type()->map_type() != NULL || (*pa)->type()->channel_type() != NULL)) { Temporary_statement* temp = Statement::make_temporary(NULL, *pa, loc); inserter->insert(temp); *pa = Expression::make_temporary_reference(temp, loc); } } break; case BUILTIN_DELETE: { // Lower to a runtime function call. const Expression_list* args = this->args(); // Since this function returns no value it must appear in // a statement by itself, so we don't have to worry about // order of evaluation of values around it. Evaluate the // map first to get order of evaluation right. Map_type* mt = args->front()->type()->map_type(); Temporary_statement* map_temp = Statement::make_temporary(mt, args->front(), loc); inserter->insert(map_temp); Temporary_statement* key_temp = Statement::make_temporary(mt->key_type(), args->back(), loc); inserter->insert(key_temp); Expression* e1 = Expression::make_type_descriptor(mt, loc); Expression* e2 = Expression::make_temporary_reference(map_temp, loc); Expression* e3 = Expression::make_temporary_reference(key_temp, loc); Runtime::Function code; switch (mt->algorithm(gogo)) { case Map_type::MAP_ALG_FAST32: case Map_type::MAP_ALG_FAST32PTR: { code = Runtime::MAPDELETE_FAST32; Type* uint32_type = Type::lookup_integer_type("uint32"); Type* uint32_ptr_type = Type::make_pointer_type(uint32_type); e3 = Expression::make_unary(OPERATOR_AND, e3, loc); e3 = Expression::make_unsafe_cast(uint32_ptr_type, e3, loc); e3 = Expression::make_dereference(e3, Expression::NIL_CHECK_NOT_NEEDED, loc); break; } case Map_type::MAP_ALG_FAST64: case Map_type::MAP_ALG_FAST64PTR: { code = Runtime::MAPDELETE_FAST64; Type* uint64_type = Type::lookup_integer_type("uint64"); Type* uint64_ptr_type = Type::make_pointer_type(uint64_type); e3 = Expression::make_unary(OPERATOR_AND, e3, loc); e3 = Expression::make_unsafe_cast(uint64_ptr_type, e3, loc); e3 = Expression::make_dereference(e3, Expression::NIL_CHECK_NOT_NEEDED, loc); break; } case Map_type::MAP_ALG_FASTSTR: code = Runtime::MAPDELETE_FASTSTR; break; default: code = Runtime::MAPDELETE; // If the call to delete is deferred, and is in a loop, // then the loop will only have a single instance of the // temporary variable. Passing the address of the // temporary variable here means that the deferred call // will see the last value in the loop, not the current // value. So for this unusual case copy the value into // the heap. if (!this->is_deferred()) e3 = Expression::make_unary(OPERATOR_AND, e3, loc); else { Expression* a = Expression::make_allocation(mt->key_type(), loc); Temporary_statement* atemp = Statement::make_temporary(NULL, a, loc); inserter->insert(atemp); a = Expression::make_temporary_reference(atemp, loc); a = Expression::make_dereference(a, NIL_CHECK_NOT_NEEDED, loc); Statement* s = Statement::make_assignment(a, e3, loc); inserter->insert(s); e3 = Expression::make_temporary_reference(atemp, loc); } } return Runtime::make_call(code, loc, 3, e1, e2, e3); } case BUILTIN_ADD: { Expression* ptr = this->args()->front(); Type* uintptr_type = Type::lookup_integer_type("uintptr"); ptr = Expression::make_cast(uintptr_type, ptr, loc); Expression* len = this->args()->back(); len = Expression::make_cast(uintptr_type, len, loc); Expression* add = Expression::make_binary(OPERATOR_PLUS, ptr, len, loc); return Expression::make_cast(this->args()->front()->type(), add, loc); } case BUILTIN_SLICE: { Expression* ptr = this->args()->front(); Temporary_statement* ptr_temp = NULL; if (!ptr->is_multi_eval_safe()) { ptr_temp = Statement::make_temporary(NULL, ptr, loc); inserter->insert(ptr_temp); ptr = Expression::make_temporary_reference(ptr_temp, loc); } Expression* len = this->args()->back(); Temporary_statement* len_temp = NULL; if (!len->is_multi_eval_safe()) { len_temp = Statement::make_temporary(NULL, len, loc); inserter->insert(len_temp); len = Expression::make_temporary_reference(len_temp, loc); } bool fits_in_int; Numeric_constant nc; if (this->args()->back()->numeric_constant_value(&nc)) { // We gave an error for constants that don't fit in int in // check_types. fits_in_int = true; } else { Integer_type* itype = this->args()->back()->type()->integer_type(); go_assert(itype != NULL); int ebits = itype->bits(); int intbits = Type::lookup_integer_type("int")->integer_type()->bits(); // We can treat ebits == intbits as small even for an // unsigned integer type, because we will convert the // value to int and then reject it in the runtime if it is // negative. fits_in_int = ebits <= intbits; } Runtime::Function code = (fits_in_int ? Runtime::UNSAFESLICE : Runtime::UNSAFESLICE64); Expression* td = Expression::make_type_descriptor(ptr->type()->points_to(), loc); Expression* check = Runtime::make_call(code, loc, 3, td, ptr, len); if (ptr_temp == NULL) ptr = ptr->copy(); else ptr = Expression::make_temporary_reference(ptr_temp, loc); Expression* nil = Expression::make_nil(loc); nil = Expression::make_cast(ptr->type(), nil, loc); Expression* is_nil = Expression::make_binary(OPERATOR_EQEQ, ptr, nil, loc); if (len_temp == NULL) len = len->copy(); else len = Expression::make_temporary_reference(len_temp, loc); Expression* zero = Expression::make_integer_ul(0, len->type(), loc); Expression* is_zero = Expression::make_binary(OPERATOR_EQEQ, len, zero, loc); Expression* cond = Expression::make_binary(OPERATOR_ANDAND, is_nil, is_zero, loc); Type* slice_type = Type::make_array_type(ptr->type()->points_to(), NULL); nil = Expression::make_nil(loc); Expression* nil_slice = Expression::make_cast(slice_type, nil, loc); if (ptr_temp == NULL) ptr = ptr->copy(); else ptr = Expression::make_temporary_reference(ptr_temp, loc); if (len_temp == NULL) len = len->copy(); else len = Expression::make_temporary_reference(len_temp, loc); Expression* cap; if (len_temp == NULL) cap = len->copy(); else cap = Expression::make_temporary_reference(len_temp, loc); Expression* slice = Expression::make_slice_value(slice_type, ptr, len, cap, loc); slice = Expression::make_conditional(cond, nil_slice, slice, loc); return Expression::make_compound(check, slice, loc); } } return this; } // Lower a make expression. Expression* Builtin_call_expression::lower_make(Statement_inserter* inserter) { Location loc = this->location(); const Expression_list* args = this->args(); if (args == NULL || args->size() < 1) { this->report_error(_("not enough arguments")); return Expression::make_error(this->location()); } Expression_list::const_iterator parg = args->begin(); Expression* first_arg = *parg; if (!first_arg->is_type_expression()) { go_error_at(first_arg->location(), "expected type"); this->set_is_error(); return Expression::make_error(this->location()); } Type* type = first_arg->type(); if (!type->in_heap()) go_error_at(first_arg->location(), "cannot make slice of go:notinheap type"); bool is_slice = false; bool is_map = false; bool is_chan = false; if (type->is_slice_type()) is_slice = true; else if (type->map_type() != NULL) is_map = true; else if (type->channel_type() != NULL) is_chan = true; else { this->report_error(_("invalid type for make function")); return Expression::make_error(this->location()); } Type_context int_context(Type::lookup_integer_type("int"), false); ++parg; Expression* len_arg; bool len_small = false; if (parg == args->end()) { if (is_slice) { this->report_error(_("length required when allocating a slice")); return Expression::make_error(this->location()); } len_arg = Expression::make_integer_ul(0, NULL, loc); len_small = true; } else { len_arg = *parg; len_arg->determine_type(&int_context); if (len_arg->type()->integer_type() == NULL) { go_error_at(len_arg->location(), "non-integer len argument in make"); return Expression::make_error(this->location()); } if (!this->check_int_value(len_arg, true, &len_small)) return Expression::make_error(this->location()); ++parg; } Expression* cap_arg = NULL; bool cap_small = false; Numeric_constant nclen; Numeric_constant nccap; unsigned long vlen; unsigned long vcap; if (is_slice && parg != args->end()) { cap_arg = *parg; cap_arg->determine_type(&int_context); if (cap_arg->type()->integer_type() == NULL) { go_error_at(cap_arg->location(), "non-integer cap argument in make"); return Expression::make_error(this->location()); } if (!this->check_int_value(cap_arg, false, &cap_small)) return Expression::make_error(this->location()); if (len_arg->numeric_constant_value(&nclen) && cap_arg->numeric_constant_value(&nccap) && nclen.to_unsigned_long(&vlen) == Numeric_constant::NC_UL_VALID && nccap.to_unsigned_long(&vcap) == Numeric_constant::NC_UL_VALID && vlen > vcap) { this->report_error(_("len larger than cap")); return Expression::make_error(this->location()); } ++parg; } if (parg != args->end()) { this->report_error(_("too many arguments to make")); return Expression::make_error(this->location()); } Location type_loc = first_arg->location(); Expression* call; if (is_slice) { Temporary_statement* len_temp = NULL; if (!len_arg->is_constant()) { len_temp = Statement::make_temporary(NULL, len_arg, loc); inserter->insert(len_temp); len_arg = Expression::make_temporary_reference(len_temp, loc); } if (cap_arg == NULL) { cap_small = len_small; if (len_temp == NULL) cap_arg = len_arg->copy(); else cap_arg = Expression::make_temporary_reference(len_temp, loc); } else if (!cap_arg->is_constant()) { Temporary_statement* cap_temp = Statement::make_temporary(NULL, cap_arg, loc); inserter->insert(cap_temp); cap_arg = Expression::make_temporary_reference(cap_temp, loc); } Type* et = type->array_type()->element_type(); Expression* type_arg = Expression::make_type_descriptor(et, type_loc); Runtime::Function code = Runtime::MAKESLICE; if (!len_small || !cap_small) code = Runtime::MAKESLICE64; Expression* mem = Runtime::make_call(code, loc, 3, type_arg, len_arg, cap_arg); mem = Expression::make_unsafe_cast(Type::make_pointer_type(et), mem, loc); Type* int_type = Type::lookup_integer_type("int"); len_arg = Expression::make_cast(int_type, len_arg->copy(), loc); cap_arg = Expression::make_cast(int_type, cap_arg->copy(), loc); call = Expression::make_slice_value(type, mem, len_arg, cap_arg, loc); } else if (is_map) { Expression* type_arg = Expression::make_type_descriptor(type, type_loc); if (!len_small) call = Runtime::make_call(Runtime::MAKEMAP64, loc, 3, type_arg, len_arg, Expression::make_nil(loc)); else { if (len_arg->numeric_constant_value(&nclen) && nclen.to_unsigned_long(&vlen) == Numeric_constant::NC_UL_VALID && vlen <= Map_type::bucket_size) call = Runtime::make_call(Runtime::MAKEMAP_SMALL, loc, 0); else call = Runtime::make_call(Runtime::MAKEMAP, loc, 3, type_arg, len_arg, Expression::make_nil(loc)); } } else if (is_chan) { Expression* type_arg = Expression::make_type_descriptor(type, type_loc); Runtime::Function code = Runtime::MAKECHAN; if (!len_small) code = Runtime::MAKECHAN64; call = Runtime::make_call(code, loc, 2, type_arg, len_arg); } else go_unreachable(); return Expression::make_unsafe_cast(type, call, loc); } // Flatten a call to the predeclared append function. We do this in // the flatten phase, not the lowering phase, so that we run after // type checking and after order_evaluations. If ASSIGN_LHS is not // NULL, this append is the right-hand-side of an assignment and // ASSIGN_LHS is the left-hand-side; in that case, set LHS directly // rather than returning a slice. This lets us omit a write barrier // in common cases like a = append(a, ...) when the slice does not // need to grow. ENCLOSING is not NULL iff ASSIGN_LHS is not NULL. Expression* Builtin_call_expression::flatten_append(Gogo* gogo, Named_object* function, Statement_inserter* inserter, Expression* assign_lhs, Block* enclosing) { if (this->is_error_expression()) return this; Location loc = this->location(); const Expression_list* args = this->args(); go_assert(args != NULL && !args->empty()); Type* slice_type = args->front()->type(); go_assert(slice_type->is_slice_type()); Type* element_type = slice_type->array_type()->element_type(); if (args->size() == 1) { // append(s) evaluates to s. if (assign_lhs != NULL) return NULL; return args->front(); } Type* int_type = Type::lookup_integer_type("int"); Type* uint_type = Type::lookup_integer_type("uint"); // Implementing // append(s1, s2...) // or // append(s1, a1, a2, a3, ...) // s1tmp := s1 Temporary_statement* s1tmp = Statement::make_temporary(NULL, args->front(), loc); inserter->insert(s1tmp); // l1tmp := len(s1tmp) Named_object* lenfn = gogo->lookup_global("len"); Expression* lenref = Expression::make_func_reference(lenfn, NULL, loc); Expression_list* call_args = new Expression_list(); call_args->push_back(Expression::make_temporary_reference(s1tmp, loc)); Expression* len = Expression::make_call(lenref, call_args, false, loc); gogo->lower_expression(function, inserter, &len); gogo->flatten_expression(function, inserter, &len); Temporary_statement* l1tmp = Statement::make_temporary(int_type, len, loc); inserter->insert(l1tmp); Temporary_statement* s2tmp = NULL; Temporary_statement* l2tmp = NULL; Expression_list* add = NULL; Expression* len2; Call_expression* makecall = NULL; if (this->is_varargs()) { go_assert(args->size() == 2); std::pair p = Expression::find_makeslice_call(args->back()); makecall = p.first; if (makecall != NULL) { // We are handling // append(s, make([]T, len[, cap])...)) // which has already been lowered to // append(s, runtime.makeslice(T, len, cap)). // We will optimize this to directly zeroing the tail, // instead of allocating a new slice then copy. // Retrieve the length and capacity. Cannot reference s2 as // we will remove the makeslice call. Expression* len_arg = makecall->args()->at(1); len_arg = Expression::make_cast(int_type, len_arg, loc); l2tmp = Statement::make_temporary(int_type, len_arg, loc); inserter->insert(l2tmp); Expression* cap_arg = makecall->args()->at(2); cap_arg = Expression::make_cast(int_type, cap_arg, loc); Temporary_statement* c2tmp = Statement::make_temporary(int_type, cap_arg, loc); inserter->insert(c2tmp); // Check bad len/cap here. // checkmakeslice(type, len, cap) // (Note that if len and cap are constants, we won't see a // makeslice call here, as it will be rewritten to a stack // allocated array by Mark_address_taken::expression.) Expression* elem = Expression::make_type_descriptor(element_type, loc); len2 = Expression::make_temporary_reference(l2tmp, loc); Expression* cap2 = Expression::make_temporary_reference(c2tmp, loc); Expression* check = Runtime::make_call(Runtime::CHECK_MAKE_SLICE, loc, 3, elem, len2, cap2); gogo->lower_expression(function, inserter, &check); gogo->flatten_expression(function, inserter, &check); Statement* s = Statement::make_statement(check, false); inserter->insert(s); // Remove the original makeslice call. Temporary_statement* ts = p.second; if (ts != NULL && ts->uses() == 1) ts->set_init(Expression::make_nil(loc)); } else { // s2tmp := s2 s2tmp = Statement::make_temporary(NULL, args->back(), loc); inserter->insert(s2tmp); // l2tmp := len(s2tmp) lenref = Expression::make_func_reference(lenfn, NULL, loc); call_args = new Expression_list(); call_args->push_back(Expression::make_temporary_reference(s2tmp, loc)); len = Expression::make_call(lenref, call_args, false, loc); gogo->lower_expression(function, inserter, &len); gogo->flatten_expression(function, inserter, &len); l2tmp = Statement::make_temporary(int_type, len, loc); inserter->insert(l2tmp); } // len2 = l2tmp len2 = Expression::make_temporary_reference(l2tmp, loc); } else { // We have to ensure that all the arguments are in variables // now, because otherwise if one of them is an index expression // into the current slice we could overwrite it before we fetch // it. add = new Expression_list(); Expression_list::const_iterator pa = args->begin(); for (++pa; pa != args->end(); ++pa) { if ((*pa)->is_multi_eval_safe()) add->push_back(*pa); else { Temporary_statement* tmp = Statement::make_temporary(NULL, *pa, loc); inserter->insert(tmp); add->push_back(Expression::make_temporary_reference(tmp, loc)); } } // len2 = len(add) len2 = Expression::make_integer_ul(add->size(), int_type, loc); } // ntmp := l1tmp + len2 Expression* ref = Expression::make_temporary_reference(l1tmp, loc); Expression* sum = Expression::make_binary(OPERATOR_PLUS, ref, len2, loc); gogo->lower_expression(function, inserter, &sum); gogo->flatten_expression(function, inserter, &sum); Temporary_statement* ntmp = Statement::make_temporary(int_type, sum, loc); inserter->insert(ntmp); // s1tmp = uint(ntmp) > uint(cap(s1tmp)) ? // growslice(type, s1tmp, ntmp) : // s1tmp[:ntmp] // Using uint here means that if the computation of ntmp overflowed, // we will call growslice which will panic. Named_object* capfn = gogo->lookup_global("cap"); Expression* capref = Expression::make_func_reference(capfn, NULL, loc); call_args = new Expression_list(); call_args->push_back(Expression::make_temporary_reference(s1tmp, loc)); Expression* cap = Expression::make_call(capref, call_args, false, loc); gogo->lower_expression(function, inserter, &cap); gogo->flatten_expression(function, inserter, &cap); Temporary_statement* c1tmp = Statement::make_temporary(int_type, cap, loc); inserter->insert(c1tmp); Expression* left = Expression::make_temporary_reference(ntmp, loc); left = Expression::make_cast(uint_type, left, loc); Expression* right = Expression::make_temporary_reference(c1tmp, loc); right = Expression::make_cast(uint_type, right, loc); Expression* cond = Expression::make_binary(OPERATOR_GT, left, right, loc); Type* unsafe_ptr_type = Type::make_pointer_type(Type::make_void_type()); Expression* a1 = Expression::make_type_descriptor(element_type, loc); Expression* a2 = Expression::make_temporary_reference(s1tmp, loc); a2 = slice_type->array_type()->get_value_pointer(gogo, a2); a2 = Expression::make_cast(unsafe_ptr_type, a2, loc); Expression* a3 = Expression::make_temporary_reference(l1tmp, loc); Expression* a4 = Expression::make_temporary_reference(c1tmp, loc); Expression* a5 = Expression::make_temporary_reference(ntmp, loc); Expression* call = Runtime::make_call(Runtime::GROWSLICE, loc, 5, a1, a2, a3, a4, a5); call = Expression::make_unsafe_cast(slice_type, call, loc); ref = Expression::make_temporary_reference(s1tmp, loc); Expression* zero = Expression::make_integer_ul(0, int_type, loc); Expression* ref2 = Expression::make_temporary_reference(ntmp, loc); ref = Expression::make_array_index(ref, zero, ref2, NULL, loc); ref->array_index_expression()->set_needs_bounds_check(false); if (assign_lhs == NULL) { Expression* rhs = Expression::make_conditional(cond, call, ref, loc); gogo->lower_expression(function, inserter, &rhs); gogo->flatten_expression(function, inserter, &rhs); ref = Expression::make_temporary_reference(s1tmp, loc); Statement* assign = Statement::make_assignment(ref, rhs, loc); inserter->insert(assign); } else { gogo->lower_expression(function, inserter, &cond); gogo->flatten_expression(function, inserter, &cond); gogo->lower_expression(function, inserter, &call); gogo->flatten_expression(function, inserter, &call); gogo->lower_expression(function, inserter, &ref); gogo->flatten_expression(function, inserter, &ref); Block* then_block = new Block(enclosing, loc); Assignment_statement* assign = Statement::make_assignment(assign_lhs, call, loc); then_block->add_statement(assign); Block* else_block = new Block(enclosing, loc); assign = Statement::make_assignment(assign_lhs->copy(), ref, loc); // This assignment will not change the pointer value, so it does // not need a write barrier. assign->set_omit_write_barrier(); else_block->add_statement(assign); Statement* s = Statement::make_if_statement(cond, then_block, else_block, loc); inserter->insert(s); ref = Expression::make_temporary_reference(s1tmp, loc); assign = Statement::make_assignment(ref, assign_lhs->copy(), loc); inserter->insert(assign); } Type* uintptr_type = Type::lookup_integer_type("uintptr"); if (this->is_varargs()) { if (makecall != NULL) { // memclr(&s1tmp[l1tmp], l2tmp*sizeof(elem)) a1 = Expression::make_temporary_reference(s1tmp, loc); ref = Expression::make_temporary_reference(l1tmp, loc); a1 = Expression::make_array_index(a1, ref, NULL, NULL, loc); a1->array_index_expression()->set_needs_bounds_check(false); a1 = Expression::make_unary(OPERATOR_AND, a1, loc); ref = Expression::make_temporary_reference(l2tmp, loc); ref = Expression::make_cast(uintptr_type, ref, loc); a2 = Expression::make_type_info(element_type, TYPE_INFO_SIZE); a2 = Expression::make_binary(OPERATOR_MULT, a2, ref, loc); if (element_type->has_pointer()) call = Runtime::make_call(Runtime::MEMCLRHASPTR, loc, 2, a1, a2); else { Type* int32_type = Type::lookup_integer_type("int32"); zero = Expression::make_integer_ul(0, int32_type, loc); call = Runtime::make_call(Runtime::BUILTIN_MEMSET, loc, 3, a1, zero, a2); } if (element_type->has_pointer()) { // For a slice containing pointers, growslice already zeroed // the memory. We only need to zero in non-growing case. // Note: growslice does not zero the memory in non-pointer case. ref = Expression::make_temporary_reference(ntmp, loc); ref = Expression::make_cast(uint_type, ref, loc); ref2 = Expression::make_temporary_reference(c1tmp, loc); ref2 = Expression::make_cast(uint_type, ref2, loc); cond = Expression::make_binary(OPERATOR_GT, ref, ref2, loc); zero = Expression::make_integer_ul(0, int_type, loc); call = Expression::make_conditional(cond, zero, call, loc); } } else { if (element_type->has_pointer()) { // copy(s1tmp[l1tmp:], s2tmp) a1 = Expression::make_temporary_reference(s1tmp, loc); ref = Expression::make_temporary_reference(l1tmp, loc); Expression* nil = Expression::make_nil(loc); a1 = Expression::make_array_index(a1, ref, nil, NULL, loc); a1->array_index_expression()->set_needs_bounds_check(false); a2 = Expression::make_temporary_reference(s2tmp, loc); Named_object* copyfn = gogo->lookup_global("copy"); Expression* copyref = Expression::make_func_reference(copyfn, NULL, loc); call_args = new Expression_list(); call_args->push_back(a1); call_args->push_back(a2); call = Expression::make_call(copyref, call_args, false, loc); } else { // memmove(&s1tmp[l1tmp], s2tmp.ptr, l2tmp*sizeof(elem)) a1 = Expression::make_temporary_reference(s1tmp, loc); ref = Expression::make_temporary_reference(l1tmp, loc); a1 = Expression::make_array_index(a1, ref, NULL, NULL, loc); a1->array_index_expression()->set_needs_bounds_check(false); a1 = Expression::make_unary(OPERATOR_AND, a1, loc); a2 = Expression::make_temporary_reference(s2tmp, loc); a2 = (a2->type()->is_string_type() ? Expression::make_string_info(a2, STRING_INFO_DATA, loc) : Expression::make_slice_info(a2, SLICE_INFO_VALUE_POINTER, loc)); ref = Expression::make_temporary_reference(l2tmp, loc); ref = Expression::make_cast(uintptr_type, ref, loc); a3 = Expression::make_type_info(element_type, TYPE_INFO_SIZE); a3 = Expression::make_binary(OPERATOR_MULT, a3, ref, loc); call = Runtime::make_call(Runtime::BUILTIN_MEMMOVE, loc, 3, a1, a2, a3); } } gogo->lower_expression(function, inserter, &call); gogo->flatten_expression(function, inserter, &call); inserter->insert(Statement::make_statement(call, false)); } else { // For each argument: // s1tmp[l1tmp+i] = a unsigned long i = 0; for (Expression_list::const_iterator pa = add->begin(); pa != add->end(); ++pa, ++i) { ref = Expression::make_temporary_reference(s1tmp, loc); ref2 = Expression::make_temporary_reference(l1tmp, loc); Expression* off = Expression::make_integer_ul(i, int_type, loc); ref2 = Expression::make_binary(OPERATOR_PLUS, ref2, off, loc); Expression* lhs = Expression::make_array_index(ref, ref2, NULL, NULL, loc); lhs->array_index_expression()->set_needs_bounds_check(false); gogo->lower_expression(function, inserter, &lhs); gogo->flatten_expression(function, inserter, &lhs); Expression* elem = *pa; if (!Type::are_identical(element_type, elem->type(), 0, NULL) && element_type->interface_type() != NULL) elem = Expression::make_cast(element_type, elem, loc); // The flatten pass runs after the write barrier pass, so we // need to insert a write barrier here if necessary. // However, if ASSIGN_LHS is not NULL, we have been called // directly before the write barrier pass. Statement* assign; if (assign_lhs != NULL || !gogo->assign_needs_write_barrier(lhs, NULL)) assign = Statement::make_assignment(lhs, elem, loc); else { Function* f = function == NULL ? NULL : function->func_value(); assign = gogo->assign_with_write_barrier(f, NULL, inserter, lhs, elem, loc); } inserter->insert(assign); } } if (assign_lhs != NULL) return NULL; return Expression::make_temporary_reference(s1tmp, loc); } // Return whether an expression has an integer value. Report an error // if not. This is used when handling calls to the predeclared make // function. Set *SMALL if the value is known to fit in type "int". bool Builtin_call_expression::check_int_value(Expression* e, bool is_length, bool *small) { *small = false; Numeric_constant nc; if (e->numeric_constant_value(&nc)) { unsigned long v; switch (nc.to_unsigned_long(&v)) { case Numeric_constant::NC_UL_VALID: break; case Numeric_constant::NC_UL_NOTINT: go_error_at(e->location(), "non-integer %s argument to make", is_length ? "len" : "cap"); return false; case Numeric_constant::NC_UL_NEGATIVE: go_error_at(e->location(), "negative %s argument to make", is_length ? "len" : "cap"); return false; case Numeric_constant::NC_UL_BIG: // We don't want to give a compile-time error for a 64-bit // value on a 32-bit target. break; } mpz_t val; if (!nc.to_int(&val)) go_unreachable(); int bits = mpz_sizeinbase(val, 2); mpz_clear(val); Type* int_type = Type::lookup_integer_type("int"); if (bits >= int_type->integer_type()->bits()) { go_error_at(e->location(), "%s argument too large for make", is_length ? "len" : "cap"); return false; } *small = true; return true; } if (e->type()->integer_type() != NULL) { int ebits = e->type()->integer_type()->bits(); int intbits = Type::lookup_integer_type("int")->integer_type()->bits(); // We can treat ebits == intbits as small even for an unsigned // integer type, because we will convert the value to int and // then reject it in the runtime if it is negative. *small = ebits <= intbits; return true; } go_error_at(e->location(), "non-integer %s argument to make", is_length ? "len" : "cap"); return false; } // Return the type of the real or imag functions, given the type of // the argument. We need to map complex64 to float32 and complex128 // to float64, so it has to be done by name. This returns NULL if it // can't figure out the type. Type* Builtin_call_expression::real_imag_type(Type* arg_type) { if (arg_type == NULL || arg_type->is_abstract()) return NULL; Named_type* nt = arg_type->named_type(); if (nt == NULL) return NULL; while (nt->real_type()->named_type() != NULL) nt = nt->real_type()->named_type(); if (nt->name() == "complex64") return Type::lookup_float_type("float32"); else if (nt->name() == "complex128") return Type::lookup_float_type("float64"); else return NULL; } // Return the type of the complex function, given the type of one of the // argments. Like real_imag_type, we have to map by name. Type* Builtin_call_expression::complex_type(Type* arg_type) { if (arg_type == NULL || arg_type->is_abstract()) return NULL; Named_type* nt = arg_type->named_type(); if (nt == NULL) return NULL; while (nt->real_type()->named_type() != NULL) nt = nt->real_type()->named_type(); if (nt->name() == "float32") return Type::lookup_complex_type("complex64"); else if (nt->name() == "float64") return Type::lookup_complex_type("complex128"); else return NULL; } // Return a single argument, or NULL if there isn't one. Expression* Builtin_call_expression::one_arg() const { const Expression_list* args = this->args(); if (args == NULL || args->size() != 1) return NULL; return args->front(); } // A traversal class which looks for a call or receive expression. class Find_call_expression : public Traverse { public: Find_call_expression() : Traverse(traverse_expressions), found_(false) { } int expression(Expression**); bool found() { return this->found_; } private: bool found_; }; int Find_call_expression::expression(Expression** pexpr) { Expression* expr = *pexpr; if (!expr->is_constant() && (expr->call_expression() != NULL || expr->receive_expression() != NULL)) { this->found_ = true; return TRAVERSE_EXIT; } return TRAVERSE_CONTINUE; } // Return whether calling len or cap on EXPR, of array type, is a // constant. The language spec says "the expressions len(s) and // cap(s) are constants if the type of s is an array or pointer to an // array and the expression s does not contain channel receives or // (non-constant) function calls." bool Builtin_call_expression::array_len_is_constant(Expression* expr) { go_assert(expr->type()->deref()->array_type() != NULL && !expr->type()->deref()->is_slice_type()); if (expr->is_constant()) return true; Find_call_expression find_call; Expression::traverse(&expr, &find_call); return !find_call.found(); } // Return whether this is constant: len of a string constant, or len // or cap of an array, or unsafe.Sizeof, unsafe.Offsetof, // unsafe.Alignof. bool Builtin_call_expression::do_is_constant() const { if (this->is_error_expression()) return true; switch (this->code_) { case BUILTIN_LEN: case BUILTIN_CAP: { if (this->seen_) return false; Expression* arg = this->one_arg(); if (arg == NULL) return false; Type* arg_type = arg->type(); if (arg_type->is_error()) return true; if (arg_type->points_to() != NULL && arg_type->points_to()->array_type() != NULL && !arg_type->points_to()->is_slice_type()) arg_type = arg_type->points_to(); if (arg_type->array_type() != NULL && arg_type->array_type()->length() != NULL) { this->seen_ = true; bool ret = Builtin_call_expression::array_len_is_constant(arg); this->seen_ = false; return ret; } if (this->code_ == BUILTIN_LEN && arg_type->is_string_type()) { this->seen_ = true; bool ret = arg->is_constant(); this->seen_ = false; return ret; } } break; case BUILTIN_SIZEOF: case BUILTIN_ALIGNOF: return this->one_arg() != NULL; case BUILTIN_OFFSETOF: { Expression* arg = this->one_arg(); if (arg == NULL) return false; return arg->field_reference_expression() != NULL; } case BUILTIN_COMPLEX: { const Expression_list* args = this->args(); if (args != NULL && args->size() == 2) return args->front()->is_constant() && args->back()->is_constant(); } break; case BUILTIN_REAL: case BUILTIN_IMAG: { Expression* arg = this->one_arg(); return arg != NULL && arg->is_constant(); } default: break; } return false; } // Return a numeric constant if possible. bool Builtin_call_expression::do_numeric_constant_value(Numeric_constant* nc) const { if (this->code_ == BUILTIN_LEN || this->code_ == BUILTIN_CAP) { Expression* arg = this->one_arg(); if (arg == NULL) return false; Type* arg_type = arg->type(); if (arg_type->is_error()) return false; if (this->code_ == BUILTIN_LEN && arg_type->is_string_type()) { std::string sval; if (arg->string_constant_value(&sval)) { nc->set_unsigned_long(Type::lookup_integer_type("int"), sval.length()); return true; } } if (arg_type->points_to() != NULL && arg_type->points_to()->array_type() != NULL && !arg_type->points_to()->is_slice_type()) arg_type = arg_type->points_to(); if (arg_type->array_type() != NULL && arg_type->array_type()->length() != NULL) { if (this->seen_) return false; // We may be replacing this expression with a constant // during lowering, so verify the type to report any errors. // It's OK to verify an array type more than once. arg_type->verify(); if (!arg_type->is_error()) { Expression* e = arg_type->array_type()->length(); this->seen_ = true; bool r = e->numeric_constant_value(nc); this->seen_ = false; if (r) { if (!nc->set_type(Type::lookup_integer_type("int"), false, this->location())) r = false; } return r; } } } else if (this->code_ == BUILTIN_SIZEOF || this->code_ == BUILTIN_ALIGNOF) { Expression* arg = this->one_arg(); if (arg == NULL) return false; Type* arg_type = arg->type(); if (arg_type->is_error()) return false; if (arg_type->is_abstract()) arg_type = arg_type->make_non_abstract_type(); if (this->seen_) return false; int64_t ret; if (this->code_ == BUILTIN_SIZEOF) { this->seen_ = true; bool ok = arg_type->backend_type_size(this->gogo_, &ret); this->seen_ = false; if (!ok) return false; } else if (this->code_ == BUILTIN_ALIGNOF) { bool ok; this->seen_ = true; if (arg->field_reference_expression() == NULL) ok = arg_type->backend_type_align(this->gogo_, &ret); else { // Calling unsafe.Alignof(s.f) returns the alignment of // the type of f when it is used as a field in a struct. ok = arg_type->backend_type_field_align(this->gogo_, &ret); } this->seen_ = false; if (!ok) return false; } else go_unreachable(); mpz_t zval; set_mpz_from_int64(&zval, ret); nc->set_int(Type::lookup_integer_type("uintptr"), zval); mpz_clear(zval); return true; } else if (this->code_ == BUILTIN_OFFSETOF) { Expression* arg = this->one_arg(); if (arg == NULL) return false; Field_reference_expression* farg = arg->field_reference_expression(); if (farg == NULL) return false; if (this->seen_) return false; int64_t total_offset = 0; while (true) { Expression* struct_expr = farg->expr(); Type* st = struct_expr->type(); if (st->struct_type() == NULL) return false; if (st->named_type() != NULL) st->named_type()->convert(this->gogo_); if (st->is_error_type()) { go_assert(saw_errors()); return false; } int64_t offset; this->seen_ = true; bool ok = st->struct_type()->backend_field_offset(this->gogo_, farg->field_index(), &offset); this->seen_ = false; if (!ok) return false; total_offset += offset; if (farg->implicit() && struct_expr->field_reference_expression() != NULL) { // Go up until we reach the original base. farg = struct_expr->field_reference_expression(); continue; } break; } mpz_t zval; set_mpz_from_int64(&zval, total_offset); nc->set_int(Type::lookup_integer_type("uintptr"), zval); mpz_clear(zval); return true; } else if (this->code_ == BUILTIN_REAL || this->code_ == BUILTIN_IMAG) { Expression* arg = this->one_arg(); if (arg == NULL) return false; Numeric_constant argnc; if (!arg->numeric_constant_value(&argnc)) return false; mpc_t val; if (!argnc.to_complex(&val)) return false; Type* type = Builtin_call_expression::real_imag_type(argnc.type()); if (this->code_ == BUILTIN_REAL) nc->set_float(type, mpc_realref(val)); else nc->set_float(type, mpc_imagref(val)); mpc_clear(val); return true; } else if (this->code_ == BUILTIN_COMPLEX) { const Expression_list* args = this->args(); if (args == NULL || args->size() != 2) return false; Numeric_constant rnc; if (!args->front()->numeric_constant_value(&rnc)) return false; Numeric_constant inc; if (!args->back()->numeric_constant_value(&inc)) return false; if (rnc.type() != NULL && !rnc.type()->is_abstract() && inc.type() != NULL && !inc.type()->is_abstract() && !Type::are_identical(rnc.type(), inc.type(), Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) return false; mpfr_t r; if (!rnc.to_float(&r)) return false; mpfr_t i; if (!inc.to_float(&i)) { mpfr_clear(r); return false; } Type* arg_type = rnc.type(); if (arg_type == NULL || arg_type->is_abstract()) arg_type = inc.type(); mpc_t val; mpc_init2(val, mpc_precision); mpc_set_fr_fr(val, r, i, MPC_RNDNN); mpfr_clear(r); mpfr_clear(i); Type* type = Builtin_call_expression::complex_type(arg_type); nc->set_complex(type, val); mpc_clear(val); return true; } return false; } // Give an error if we are discarding the value of an expression which // should not normally be discarded. We don't give an error for // discarding the value of an ordinary function call, but we do for // builtin functions, purely for consistency with the gc compiler. bool Builtin_call_expression::do_discarding_value() { switch (this->code_) { case BUILTIN_INVALID: default: go_unreachable(); case BUILTIN_APPEND: case BUILTIN_CAP: case BUILTIN_COMPLEX: case BUILTIN_IMAG: case BUILTIN_LEN: case BUILTIN_MAKE: case BUILTIN_NEW: case BUILTIN_REAL: case BUILTIN_ADD: case BUILTIN_ALIGNOF: case BUILTIN_OFFSETOF: case BUILTIN_SIZEOF: case BUILTIN_SLICE: this->unused_value_error(); return false; case BUILTIN_CLOSE: case BUILTIN_COPY: case BUILTIN_DELETE: case BUILTIN_PANIC: case BUILTIN_PRINT: case BUILTIN_PRINTLN: case BUILTIN_RECOVER: return true; } } // Return the type. Type* Builtin_call_expression::do_type() { if (this->is_error_expression()) return Type::make_error_type(); switch (this->code_) { case BUILTIN_INVALID: default: return Type::make_error_type(); case BUILTIN_NEW: { const Expression_list* args = this->args(); if (args == NULL || args->empty()) return Type::make_error_type(); return Type::make_pointer_type(args->front()->type()); } case BUILTIN_MAKE: { const Expression_list* args = this->args(); if (args == NULL || args->empty()) return Type::make_error_type(); return args->front()->type(); } case BUILTIN_CAP: case BUILTIN_COPY: case BUILTIN_LEN: return Type::lookup_integer_type("int"); case BUILTIN_ALIGNOF: case BUILTIN_OFFSETOF: case BUILTIN_SIZEOF: return Type::lookup_integer_type("uintptr"); case BUILTIN_CLOSE: case BUILTIN_DELETE: case BUILTIN_PANIC: case BUILTIN_PRINT: case BUILTIN_PRINTLN: return Type::make_void_type(); case BUILTIN_RECOVER: return Type::make_empty_interface_type(Linemap::predeclared_location()); case BUILTIN_APPEND: { const Expression_list* args = this->args(); if (args == NULL || args->empty()) return Type::make_error_type(); Type *ret = args->front()->type(); if (!ret->is_slice_type()) return Type::make_error_type(); return ret; } case BUILTIN_REAL: case BUILTIN_IMAG: { Expression* arg = this->one_arg(); if (arg == NULL) return Type::make_error_type(); Type* t = arg->type(); if (t->is_abstract()) t = t->make_non_abstract_type(); t = Builtin_call_expression::real_imag_type(t); if (t == NULL) t = Type::make_error_type(); return t; } case BUILTIN_COMPLEX: { const Expression_list* args = this->args(); if (args == NULL || args->size() != 2) return Type::make_error_type(); Type* t = args->front()->type(); if (t->is_abstract()) { t = args->back()->type(); if (t->is_abstract()) t = t->make_non_abstract_type(); } t = Builtin_call_expression::complex_type(t); if (t == NULL) t = Type::make_error_type(); return t; } case BUILTIN_ADD: return Type::make_pointer_type(Type::make_void_type()); case BUILTIN_SLICE: const Expression_list* args = this->args(); if (args == NULL || args->size() != 2) return Type::make_error_type(); Type* pt = args->front()->type()->points_to(); if (pt == NULL) return Type::make_error_type(); return Type::make_array_type(pt, NULL); } } // Determine the type. void Builtin_call_expression::do_determine_type(const Type_context* context) { if (!this->determining_types()) return; this->fn()->determine_type_no_context(); const Expression_list* args = this->args(); bool is_print; Type* arg_type = NULL; Type* trailing_arg_types = NULL; switch (this->code_) { case BUILTIN_PRINT: case BUILTIN_PRINTLN: // Do not force a large integer constant to "int". is_print = true; break; case BUILTIN_REAL: case BUILTIN_IMAG: arg_type = Builtin_call_expression::complex_type(context->type); if (arg_type == NULL) arg_type = Type::lookup_complex_type("complex128"); is_print = false; break; case BUILTIN_COMPLEX: { // For the complex function the type of one operand can // determine the type of the other, as in a binary expression. arg_type = Builtin_call_expression::real_imag_type(context->type); if (arg_type == NULL) arg_type = Type::lookup_float_type("float64"); if (args != NULL && args->size() == 2) { Type* t1 = args->front()->type(); Type* t2 = args->back()->type(); if (!t1->is_abstract()) arg_type = t1; else if (!t2->is_abstract()) arg_type = t2; } is_print = false; } break; case BUILTIN_APPEND: if (!this->is_varargs() && args != NULL && !args->empty() && args->front()->type()->is_slice_type()) trailing_arg_types = args->front()->type()->array_type()->element_type(); is_print = false; break; case BUILTIN_ADD: case BUILTIN_SLICE: // Both unsafe.Add and unsafe.Slice take two arguments, and the // second arguments defaults to "int". if (args != NULL && args->size() == 2) { if (this->code_ == BUILTIN_SLICE) args->front()->determine_type_no_context(); else { Type* pointer = Type::make_pointer_type(Type::make_void_type()); Type_context subcontext(pointer, false); args->front()->determine_type(&subcontext); } Type* int_type = Type::lookup_integer_type("int"); Type_context subcontext(int_type, false); args->back()->determine_type(&subcontext); return; } is_print = false; break; default: is_print = false; break; } if (args != NULL) { for (Expression_list::const_iterator pa = args->begin(); pa != args->end(); ++pa) { Type_context subcontext; subcontext.type = arg_type; if (is_print) { // We want to print large constants, we so can't just // use the appropriate nonabstract type. Use uint64 for // an integer if we know it is nonnegative, otherwise // use int64 for a integer, otherwise use float64 for a // float or complex128 for a complex. Type* want_type = NULL; Type* atype = (*pa)->type(); if (atype->is_abstract()) { if (atype->integer_type() != NULL) { Numeric_constant nc; if (this->numeric_constant_value(&nc)) { mpz_t val; if (nc.to_int(&val)) { if (mpz_sgn(val) >= 0) want_type = Type::lookup_integer_type("uint64"); mpz_clear(val); } } if (want_type == NULL) want_type = Type::lookup_integer_type("int64"); } else if (atype->float_type() != NULL) want_type = Type::lookup_float_type("float64"); else if (atype->complex_type() != NULL) want_type = Type::lookup_complex_type("complex128"); else if (atype->is_abstract_string_type()) want_type = Type::lookup_string_type(); else if (atype->is_abstract_boolean_type()) want_type = Type::lookup_bool_type(); else go_unreachable(); subcontext.type = want_type; } } (*pa)->determine_type(&subcontext); if (trailing_arg_types != NULL) { arg_type = trailing_arg_types; trailing_arg_types = NULL; } } } } // If there is exactly one argument, return true. Otherwise give an // error message and return false. bool Builtin_call_expression::check_one_arg() { const Expression_list* args = this->args(); if (args == NULL || args->size() < 1) { this->report_error(_("not enough arguments")); return false; } else if (args->size() > 1) { this->report_error(_("too many arguments")); return false; } if (args->front()->is_error_expression() || args->front()->type()->is_error()) { this->set_is_error(); return false; } return true; } // Check argument types for a builtin function. void Builtin_call_expression::do_check_types(Gogo*) { if (this->is_error_expression()) return; switch (this->code_) { case BUILTIN_INVALID: case BUILTIN_NEW: case BUILTIN_MAKE: case BUILTIN_DELETE: return; case BUILTIN_LEN: case BUILTIN_CAP: { // The single argument may be either a string or an array or a // map or a channel, or a pointer to a closed array. if (this->check_one_arg()) { Type* arg_type = this->one_arg()->type(); if (arg_type->points_to() != NULL && arg_type->points_to()->array_type() != NULL && !arg_type->points_to()->is_slice_type()) arg_type = arg_type->points_to(); if (this->code_ == BUILTIN_CAP) { if (!arg_type->is_error() && arg_type->array_type() == NULL && arg_type->channel_type() == NULL) this->report_error(_("argument must be array or slice " "or channel")); } else { if (!arg_type->is_error() && !arg_type->is_string_type() && arg_type->array_type() == NULL && arg_type->map_type() == NULL && arg_type->channel_type() == NULL) this->report_error(_("argument must be string or " "array or slice or map or channel")); } } } break; case BUILTIN_PRINT: case BUILTIN_PRINTLN: { const Expression_list* args = this->args(); if (args != NULL) { for (Expression_list::const_iterator p = args->begin(); p != args->end(); ++p) { Type* type = (*p)->type(); if (type->is_error() || type->is_string_type() || type->integer_type() != NULL || type->float_type() != NULL || type->complex_type() != NULL || type->is_boolean_type() || type->points_to() != NULL || type->interface_type() != NULL || type->channel_type() != NULL || type->map_type() != NULL || type->function_type() != NULL || type->is_slice_type()) ; else if ((*p)->is_type_expression()) { // If this is a type expression it's going to give // an error anyhow, so we don't need one here. } else this->report_error(_("unsupported argument type to " "builtin function")); } } } break; case BUILTIN_CLOSE: if (this->check_one_arg()) { if (this->one_arg()->type()->channel_type() == NULL) this->report_error(_("argument must be channel")); else if (!this->one_arg()->type()->channel_type()->may_send()) this->report_error(_("cannot close receive-only channel")); } break; case BUILTIN_PANIC: case BUILTIN_SIZEOF: case BUILTIN_ALIGNOF: if (this->check_one_arg()) { Expression* arg = this->one_arg(); if (arg->type()->is_void_type()) this->report_error(_("argument to builtin has void type")); } break; case BUILTIN_RECOVER: if (this->args() != NULL && !this->args()->empty() && !this->recover_arg_is_set_) this->report_error(_("too many arguments")); break; case BUILTIN_OFFSETOF: if (this->check_one_arg()) { Expression* arg = this->one_arg(); if (arg->field_reference_expression() == NULL) this->report_error(_("argument must be a field reference")); } break; case BUILTIN_COPY: { const Expression_list* args = this->args(); if (args == NULL || args->size() < 2) { this->report_error(_("not enough arguments")); break; } else if (args->size() > 2) { this->report_error(_("too many arguments")); break; } Type* arg1_type = args->front()->type(); Type* arg2_type = args->back()->type(); if (arg1_type->is_error() || arg2_type->is_error()) { this->set_is_error(); break; } Type* e1; if (arg1_type->is_slice_type()) e1 = arg1_type->array_type()->element_type(); else { this->report_error(_("left argument must be a slice")); break; } if (arg2_type->is_slice_type()) { Type* e2 = arg2_type->array_type()->element_type(); if (!Type::are_identical(e1, e2, Type::COMPARE_TAGS, NULL)) this->report_error(_("element types must be the same")); } else if (arg2_type->is_string_type()) { if (e1->integer_type() == NULL || !e1->integer_type()->is_byte()) this->report_error(_("first argument must be []byte")); } else this->report_error(_("second argument must be slice or string")); } break; case BUILTIN_APPEND: { const Expression_list* args = this->args(); if (args == NULL || args->empty()) { this->report_error(_("not enough arguments")); break; } Type* slice_type = args->front()->type(); if (!slice_type->is_slice_type()) { if (slice_type->is_error_type()) break; if (slice_type->is_nil_type()) go_error_at(args->front()->location(), "use of untyped nil"); else go_error_at(args->front()->location(), "argument 1 must be a slice"); this->set_is_error(); break; } Type* element_type = slice_type->array_type()->element_type(); if (!element_type->in_heap()) go_error_at(args->front()->location(), "cannot append to slice of go:notinheap type"); if (this->is_varargs()) { if (!args->back()->type()->is_slice_type() && !args->back()->type()->is_string_type()) { go_error_at(args->back()->location(), "invalid use of %<...%> with non-slice/non-string"); this->set_is_error(); break; } if (args->size() < 2) { this->report_error(_("not enough arguments")); break; } if (args->size() > 2) { this->report_error(_("too many arguments")); break; } if (args->back()->type()->is_string_type() && element_type->integer_type() != NULL && element_type->integer_type()->is_byte()) { // Permit append(s1, s2...) when s1 is a slice of // bytes and s2 is a string type. } else { // We have to test for assignment compatibility to a // slice of the element type, which is not necessarily // the same as the type of the first argument: the // first argument might have a named type. Type* check_type = Type::make_array_type(element_type, NULL); std::string reason; if (!Type::are_assignable(check_type, args->back()->type(), &reason)) { if (reason.empty()) go_error_at(args->back()->location(), "argument 2 has invalid type"); else go_error_at(args->back()->location(), "argument 2 has invalid type (%s)", reason.c_str()); this->set_is_error(); break; } } } else { Expression_list::const_iterator pa = args->begin(); int i = 2; for (++pa; pa != args->end(); ++pa, ++i) { std::string reason; if (!Type::are_assignable(element_type, (*pa)->type(), &reason)) { if (reason.empty()) go_error_at((*pa)->location(), "argument %d has incompatible type", i); else go_error_at((*pa)->location(), "argument %d has incompatible type (%s)", i, reason.c_str()); this->set_is_error(); } } } } break; case BUILTIN_REAL: case BUILTIN_IMAG: if (this->check_one_arg()) { if (this->one_arg()->type()->complex_type() == NULL) this->report_error(_("argument must have complex type")); } break; case BUILTIN_COMPLEX: { const Expression_list* args = this->args(); if (args == NULL || args->size() < 2) this->report_error(_("not enough arguments")); else if (args->size() > 2) this->report_error(_("too many arguments")); else if (args->front()->is_error_expression() || args->front()->type()->is_error() || args->back()->is_error_expression() || args->back()->type()->is_error()) this->set_is_error(); else if (!Type::are_identical(args->front()->type(), args->back()->type(), Type::COMPARE_TAGS, NULL)) this->report_error(_("complex arguments must have identical types")); else if (args->front()->type()->float_type() == NULL) this->report_error(_("complex arguments must have " "floating-point type")); } break; case BUILTIN_ADD: case BUILTIN_SLICE: { Numeric_constant nc; unsigned long v; const Expression_list* args = this->args(); if (args == NULL || args->size() < 2) this->report_error(_("not enough arguments")); else if (args->size() > 2) this->report_error(_("too many arguments")); else if (args->front()->is_error_expression() || args->front()->type()->is_error() || args->back()->is_error_expression() || args->back()->type()->is_error()) this->set_is_error(); else if (args->back()->type()->integer_type() == NULL && (!args->back()->type()->is_abstract() || !args->back()->numeric_constant_value(&nc) || (nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT))) { if (this->code_ == BUILTIN_ADD) go_error_at(args->back()->location(), "non-integer offset"); else go_error_at(args->back()->location(), "non-integer size"); } else if (this->code_ == BUILTIN_ADD) { Type* pointer_type = Type::make_pointer_type(Type::make_void_type()); std::string reason; if (!Type::are_assignable(pointer_type, args->front()->type(), &reason)) { if (reason.empty()) go_error_at(args->front()->location(), "argument 1 has incompatible type"); else go_error_at(args->front()->location(), "argument 1 has incompatible type (%s)", reason.c_str()); this->set_is_error(); } } else { if (args->front()->type()->points_to() == NULL) { go_error_at(args->front()->location(), "argument 1 must be a pointer"); this->set_is_error(); } unsigned int int_bits = Type::lookup_integer_type("int")->integer_type()->bits(); mpz_t ival; if (args->back()->numeric_constant_value(&nc) && nc.to_int(&ival)) { if (mpz_sgn(ival) < 0 || mpz_sizeinbase(ival, 2) >= int_bits) { go_error_at(args->back()->location(), "slice length out of range"); this->set_is_error(); } mpz_clear(ival); } } } break; default: go_unreachable(); } } Expression* Builtin_call_expression::do_copy() { Call_expression* bce = new Builtin_call_expression(this->gogo_, this->fn()->copy(), (this->args() == NULL ? NULL : this->args()->copy()), this->is_varargs(), this->location()); if (this->varargs_are_lowered()) bce->set_varargs_are_lowered(); if (this->is_deferred()) bce->set_is_deferred(); if (this->is_concurrent()) bce->set_is_concurrent(); return bce; } // Return the backend representation for a builtin function. Bexpression* Builtin_call_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Location location = this->location(); if (this->is_erroneous_call()) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } switch (this->code_) { case BUILTIN_INVALID: case BUILTIN_NEW: case BUILTIN_MAKE: case BUILTIN_ADD: case BUILTIN_SLICE: go_unreachable(); case BUILTIN_LEN: case BUILTIN_CAP: { const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 1); Expression* arg = args->front(); Type* arg_type = arg->type(); if (this->seen_) { go_assert(saw_errors()); return context->backend()->error_expression(); } this->seen_ = true; this->seen_ = false; if (arg_type->points_to() != NULL) { arg_type = arg_type->points_to(); go_assert(arg_type->array_type() != NULL && !arg_type->is_slice_type()); arg = Expression::make_dereference(arg, NIL_CHECK_DEFAULT, location); } Type* int_type = Type::lookup_integer_type("int"); Expression* val; if (this->code_ == BUILTIN_LEN) { if (arg_type->is_string_type()) val = Expression::make_string_info(arg, STRING_INFO_LENGTH, location); else if (arg_type->array_type() != NULL) { if (this->seen_) { go_assert(saw_errors()); return context->backend()->error_expression(); } this->seen_ = true; val = arg_type->array_type()->get_length(gogo, arg); this->seen_ = false; } else if (arg_type->map_type() != NULL || arg_type->channel_type() != NULL) { // The first field is the length. If the pointer is // nil, the length is zero. Type* pint_type = Type::make_pointer_type(int_type); arg = Expression::make_unsafe_cast(pint_type, arg, location); Expression* nil = Expression::make_nil(location); nil = Expression::make_cast(pint_type, nil, location); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, arg, nil, location); Expression* zero = Expression::make_integer_ul(0, int_type, location); Expression* indir = Expression::make_dereference(arg, NIL_CHECK_NOT_NEEDED, location); val = Expression::make_conditional(cmp, zero, indir, location); } else go_unreachable(); } else { if (arg_type->array_type() != NULL) { if (this->seen_) { go_assert(saw_errors()); return context->backend()->error_expression(); } this->seen_ = true; val = arg_type->array_type()->get_capacity(gogo, arg); this->seen_ = false; } else if (arg_type->channel_type() != NULL) { // The second field is the capacity. If the pointer // is nil, the capacity is zero. Type* uintptr_type = Type::lookup_integer_type("uintptr"); Type* pint_type = Type::make_pointer_type(int_type); Expression* parg = Expression::make_unsafe_cast(uintptr_type, arg, location); int off = int_type->integer_type()->bits() / 8; Expression* eoff = Expression::make_integer_ul(off, uintptr_type, location); parg = Expression::make_binary(OPERATOR_PLUS, parg, eoff, location); parg = Expression::make_unsafe_cast(pint_type, parg, location); Expression* nil = Expression::make_nil(location); nil = Expression::make_cast(pint_type, nil, location); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, arg, nil, location); Expression* zero = Expression::make_integer_ul(0, int_type, location); Expression* indir = Expression::make_dereference(parg, NIL_CHECK_NOT_NEEDED, location); val = Expression::make_conditional(cmp, zero, indir, location); } else go_unreachable(); } return Expression::make_cast(int_type, val, location)->get_backend(context); } case BUILTIN_PRINT: case BUILTIN_PRINTLN: { const bool is_ln = this->code_ == BUILTIN_PRINTLN; Expression* print_stmts = Runtime::make_call(Runtime::PRINTLOCK, location, 0); const Expression_list* call_args = this->args(); if (call_args != NULL) { for (Expression_list::const_iterator p = call_args->begin(); p != call_args->end(); ++p) { if (is_ln && p != call_args->begin()) { Expression* print_space = Runtime::make_call(Runtime::PRINTSP, location, 0); print_stmts = Expression::make_compound(print_stmts, print_space, location); } Expression* arg = *p; Type* type = arg->type(); Runtime::Function code; if (type->is_string_type()) code = Runtime::PRINTSTRING; else if (type->integer_type() != NULL && type->integer_type()->is_unsigned()) { Type* itype = Type::lookup_integer_type("uint64"); arg = Expression::make_cast(itype, arg, location); if (gogo->compiling_runtime() && type->named_type() != NULL && gogo->unpack_hidden_name(type->named_type()->name()) == "hex") code = Runtime::PRINTHEX; else code = Runtime::PRINTUINT; } else if (type->integer_type() != NULL) { Type* itype = Type::lookup_integer_type("int64"); arg = Expression::make_cast(itype, arg, location); code = Runtime::PRINTINT; } else if (type->float_type() != NULL) { Type* dtype = Type::lookup_float_type("float64"); arg = Expression::make_cast(dtype, arg, location); code = Runtime::PRINTFLOAT; } else if (type->complex_type() != NULL) { Type* ctype = Type::lookup_complex_type("complex128"); arg = Expression::make_cast(ctype, arg, location); code = Runtime::PRINTCOMPLEX; } else if (type->is_boolean_type()) code = Runtime::PRINTBOOL; else if (type->points_to() != NULL || type->channel_type() != NULL || type->map_type() != NULL || type->function_type() != NULL) { arg = Expression::make_cast(type, arg, location); code = Runtime::PRINTPOINTER; } else if (type->interface_type() != NULL) { if (type->interface_type()->is_empty()) code = Runtime::PRINTEFACE; else code = Runtime::PRINTIFACE; } else if (type->is_slice_type()) code = Runtime::PRINTSLICE; else { go_assert(saw_errors()); return context->backend()->error_expression(); } Expression* call = Runtime::make_call(code, location, 1, arg); print_stmts = Expression::make_compound(print_stmts, call, location); } } if (is_ln) { Expression* print_nl = Runtime::make_call(Runtime::PRINTNL, location, 0); print_stmts = Expression::make_compound(print_stmts, print_nl, location); } Expression* unlock = Runtime::make_call(Runtime::PRINTUNLOCK, location, 0); print_stmts = Expression::make_compound(print_stmts, unlock, location); return print_stmts->get_backend(context); } case BUILTIN_PANIC: { const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 1); Expression* arg = args->front(); Type *empty = Type::make_empty_interface_type(Linemap::predeclared_location()); arg = Expression::convert_for_assignment(gogo, empty, arg, location); Expression* panic = Runtime::make_call(Runtime::GOPANIC, location, 1, arg); return panic->get_backend(context); } case BUILTIN_RECOVER: { // The argument is set when building recover thunks. It's a // boolean value which is true if we can recover a value now. const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 1); Expression* arg = args->front(); Type *empty = Type::make_empty_interface_type(Linemap::predeclared_location()); Expression* nil = Expression::make_nil(location); nil = Expression::make_interface_value(empty, nil, nil, location); // We need to handle a deferred call to recover specially, // because it changes whether it can recover a panic or not. // See test7 in test/recover1.go. Expression* recover = Runtime::make_call((this->is_deferred() ? Runtime::DEFERREDRECOVER : Runtime::GORECOVER), location, 0); Expression* cond = Expression::make_conditional(arg, recover, nil, location); return cond->get_backend(context); } case BUILTIN_CLOSE: { const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 1); Expression* arg = args->front(); Expression* close = Runtime::make_call(Runtime::CLOSE, location, 1, arg); return close->get_backend(context); } case BUILTIN_SIZEOF: case BUILTIN_OFFSETOF: case BUILTIN_ALIGNOF: { Numeric_constant nc; unsigned long val; if (!this->numeric_constant_value(&nc) || nc.to_unsigned_long(&val) != Numeric_constant::NC_UL_VALID) { go_assert(saw_errors()); return context->backend()->error_expression(); } Type* uintptr_type = Type::lookup_integer_type("uintptr"); mpz_t ival; nc.get_int(&ival); Expression* int_cst = Expression::make_integer_z(&ival, uintptr_type, location); mpz_clear(ival); return int_cst->get_backend(context); } case BUILTIN_COPY: // Handled in Builtin_call_expression::do_flatten. go_unreachable(); case BUILTIN_APPEND: // Handled in Builtin_call_expression::flatten_append. go_unreachable(); case BUILTIN_REAL: case BUILTIN_IMAG: { const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 1); Bexpression* ret; Bexpression* bcomplex = args->front()->get_backend(context); if (this->code_ == BUILTIN_REAL) ret = gogo->backend()->real_part_expression(bcomplex, location); else ret = gogo->backend()->imag_part_expression(bcomplex, location); return ret; } case BUILTIN_COMPLEX: { const Expression_list* args = this->args(); go_assert(args != NULL && args->size() == 2); Bexpression* breal = args->front()->get_backend(context); Bexpression* bimag = args->back()->get_backend(context); return gogo->backend()->complex_expression(breal, bimag, location); } default: go_unreachable(); } } // We have to support exporting a builtin call expression, because // code can set a constant to the result of a builtin expression. void Builtin_call_expression::do_export(Export_function_body* efb) const { Numeric_constant nc; if (this->numeric_constant_value(&nc)) { if (nc.is_int()) { mpz_t val; nc.get_int(&val); Integer_expression::export_integer(efb, val); mpz_clear(val); } else if (nc.is_float()) { mpfr_t fval; nc.get_float(&fval); Float_expression::export_float(efb, fval); mpfr_clear(fval); } else if (nc.is_complex()) { mpc_t cval; nc.get_complex(&cval); Complex_expression::export_complex(efb, cval); mpc_clear(cval); } else go_unreachable(); // A trailing space lets us reliably identify the end of the number. efb->write_c_string(" "); } else if (this->code_ == BUILTIN_ADD || this->code_ == BUILTIN_SLICE) { char buf[50]; snprintf(buf, sizeof buf, "%s", efb->unsafe_package_index(), (this->code_ == BUILTIN_ADD ? "Add" : "Slice")); efb->write_c_string(buf); this->export_arguments(efb); } else { const char *s = NULL; switch (this->code_) { default: go_unreachable(); case BUILTIN_APPEND: s = "append"; break; case BUILTIN_COPY: s = "copy"; break; case BUILTIN_LEN: s = "len"; break; case BUILTIN_CAP: s = "cap"; break; case BUILTIN_DELETE: s = "delete"; break; case BUILTIN_PRINT: s = "print"; break; case BUILTIN_PRINTLN: s = "println"; break; case BUILTIN_PANIC: s = "panic"; break; case BUILTIN_RECOVER: s = "recover"; break; case BUILTIN_CLOSE: s = "close"; break; case BUILTIN_REAL: s = "real"; break; case BUILTIN_IMAG: s = "imag"; break; case BUILTIN_COMPLEX: s = "complex"; break; } efb->write_c_string(s); this->export_arguments(efb); } } // Class Call_expression. // A Go function can be viewed in a couple of different ways. The // code of a Go function becomes a backend function with parameters // whose types are simply the backend representation of the Go types. // If there are multiple results, they are returned as a backend // struct. // However, when Go code refers to a function other than simply // calling it, the backend type of that function is actually a struct. // The first field of the struct points to the Go function code // (sometimes a wrapper as described below). The remaining fields // hold addresses of closed-over variables. This struct is called a // closure. // There are a few cases to consider. // A direct function call of a known function in package scope. In // this case there are no closed-over variables, and we know the name // of the function code. We can simply produce a backend call to the // function directly, and not worry about the closure. // A direct function call of a known function literal. In this case // we know the function code and we know the closure. We generate the // function code such that it expects an additional final argument of // the closure type. We pass the closure as the last argument, after // the other arguments. // An indirect function call. In this case we have a closure. We // load the pointer to the function code from the first field of the // closure. We pass the address of the closure as the last argument. // A call to a method of an interface. Type methods are always at // package scope, so we call the function directly, and don't worry // about the closure. // This means that for a function at package scope we have two cases. // One is the direct call, which has no closure. The other is the // indirect call, which does have a closure. We can't simply ignore // the closure, even though it is the last argument, because that will // fail on targets where the function pops its arguments. So when // generating a closure for a package-scope function we set the // function code pointer in the closure to point to a wrapper // function. This wrapper function accepts a final argument that // points to the closure, ignores it, and calls the real function as a // direct function call. This wrapper will normally be efficient, and // can often simply be a tail call to the real function. // We don't use GCC's static chain pointer because 1) we don't need // it; 2) GCC only permits using a static chain to call a known // function, so we can't use it for an indirect call anyhow. Since we // can't use it for an indirect call, we may as well not worry about // using it for a direct call either. // We pass the closure last rather than first because it means that // the function wrapper we put into a closure for a package-scope // function can normally just be a tail call to the real function. // For method expressions we generate a wrapper that loads the // receiver from the closure and then calls the method. This // unfortunately forces reshuffling the arguments, since there is a // new first argument, but we can't avoid reshuffling either for // method expressions or for indirect calls of package-scope // functions, and since the latter are more common we reshuffle for // method expressions. // Note that the Go code retains the Go types. The extra final // argument only appears when we convert to the backend // representation. // Traversal. int Call_expression::do_traverse(Traverse* traverse) { // If we are calling a function in a different package that returns // an unnamed type, this may be the only chance we get to traverse // that type. We don't traverse this->type_ because it may be a // Call_multiple_result_type that will just lead back here. if (this->type_ != NULL && !this->type_->is_error_type()) { Function_type *fntype = this->get_function_type(); if (fntype != NULL && Type::traverse(fntype, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } if (Expression::traverse(&this->fn_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (this->args_ != NULL) { if (this->args_->traverse(traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } return TRAVERSE_CONTINUE; } // Lower a call statement. Expression* Call_expression::do_lower(Gogo* gogo, Named_object* function, Statement_inserter* inserter, int) { Location loc = this->location(); if (this->is_error_expression()) return Expression::make_error(loc); // A type cast can look like a function call. if (this->fn_->is_type_expression() && this->args_ != NULL && this->args_->size() == 1) { if (this->expected_result_count_ != 0 && this->expected_result_count_ != 1) { this->report_error(_("type conversion result count mismatch")); return Expression::make_error(loc); } return Expression::make_cast(this->fn_->type(), this->args_->front(), loc); } // Because do_type will return an error type and thus prevent future // errors, check for that case now to ensure that the error gets // reported. Function_type* fntype = this->get_function_type(); if (fntype == NULL) { if (!this->fn_->type()->is_error()) this->report_error(_("expected function")); this->set_is_error(); return this; } // Handle an argument which is a call to a function which returns // multiple results. if (this->args_ != NULL && this->args_->size() == 1 && this->args_->front()->call_expression() != NULL) { size_t rc = this->args_->front()->call_expression()->result_count(); if (rc > 1 && ((fntype->parameters() != NULL && (fntype->parameters()->size() == rc || (fntype->is_varargs() && fntype->parameters()->size() - 1 <= rc))) || fntype->is_builtin())) { Call_expression* call = this->args_->front()->call_expression(); call->set_is_multi_value_arg(); if (this->is_varargs_) { // It is not clear which result of a multiple result call // the ellipsis operator should be applied to. If we unpack the // the call into its individual results here, the ellipsis will be // applied to the last result. go_error_at(call->location(), _("multiple-value argument in single-value context")); return Expression::make_error(call->location()); } Expression_list* args = new Expression_list; for (size_t i = 0; i < rc; ++i) args->push_back(Expression::make_call_result(call, i)); // We can't return a new call expression here, because this // one may be referenced by Call_result expressions. We // also can't delete the old arguments, because we may still // traverse them somewhere up the call stack. FIXME. this->args_ = args; } } // Recognize a call to a builtin function. if (fntype->is_builtin()) { Builtin_call_expression* bce = new Builtin_call_expression(gogo, this->fn_, this->args_, this->is_varargs_, loc); if (this->is_deferred_) bce->set_is_deferred(); if (this->is_concurrent_) bce->set_is_concurrent(); return bce; } // If this call returns multiple results, create a temporary // variable to hold them. if (this->result_count() > 1 && this->call_temp_ == NULL) { Struct_field_list* sfl = new Struct_field_list(); const Typed_identifier_list* results = fntype->results(); int i = 0; char buf[20]; for (Typed_identifier_list::const_iterator p = results->begin(); p != results->end(); ++p, ++i) { snprintf(buf, sizeof buf, "res%d", i); sfl->push_back(Struct_field(Typed_identifier(buf, p->type(), loc))); } Struct_type* st = Type::make_struct_type(sfl, loc); st->set_is_struct_incomparable(); st->set_is_results_struct(); this->call_temp_ = Statement::make_temporary(st, NULL, loc); inserter->insert(this->call_temp_); } // Handle a call to a varargs function by packaging up the extra // parameters. if (fntype->is_varargs()) { const Typed_identifier_list* parameters = fntype->parameters(); go_assert(parameters != NULL && !parameters->empty()); Type* varargs_type = parameters->back().type(); this->lower_varargs(gogo, function, inserter, varargs_type, parameters->size(), SLICE_STORAGE_MAY_ESCAPE); } // If this is call to a method, call the method directly passing the // object as the first parameter. Bound_method_expression* bme = this->fn_->bound_method_expression(); if (bme != NULL && !this->is_deferred_ && !this->is_concurrent_) { Named_object* methodfn = bme->function(); Function_type* mft = (methodfn->is_function() ? methodfn->func_value()->type() : methodfn->func_declaration_value()->type()); Expression* first_arg = bme->first_argument(); // We always pass a pointer when calling a method, except for // direct interface types when calling a value method. if (!first_arg->type()->is_error() && first_arg->type()->points_to() == NULL && !first_arg->type()->is_direct_iface_type()) { first_arg = Expression::make_unary(OPERATOR_AND, first_arg, loc); // We may need to create a temporary variable so that we can // take the address. We can't do that here because it will // mess up the order of evaluation. Unary_expression* ue = static_cast(first_arg); ue->set_create_temp(); } else if (mft->receiver()->type()->points_to() == NULL && first_arg->type()->points_to() != NULL && first_arg->type()->points_to()->is_direct_iface_type()) first_arg = Expression::make_dereference(first_arg, Expression::NIL_CHECK_DEFAULT, loc); // If we are calling a method which was inherited from an // embedded struct, and the method did not get a stub, then the // first type may be wrong. Type* fatype = bme->first_argument_type(); if (fatype != NULL) { if (fatype->points_to() == NULL) fatype = Type::make_pointer_type(fatype); first_arg = Expression::make_unsafe_cast(fatype, first_arg, loc); } Expression_list* new_args = new Expression_list(); new_args->push_back(first_arg); if (this->args_ != NULL) { for (Expression_list::const_iterator p = this->args_->begin(); p != this->args_->end(); ++p) new_args->push_back(*p); } // We have to change in place because this structure may be // referenced by Call_result_expressions. We can't delete the // old arguments, because we may be traversing them up in some // caller. FIXME. this->args_ = new_args; this->fn_ = Expression::make_func_reference(methodfn, NULL, bme->location()); } // If this is a call to an imported function for which we have an // inlinable function body, add it to the list of functions to give // to the backend as inlining opportunities. Func_expression* fe = this->fn_->func_expression(); if (fe != NULL && fe->named_object()->is_function_declaration() && fe->named_object()->func_declaration_value()->has_imported_body()) gogo->add_imported_inlinable_function(fe->named_object()); return this; } // Lower a call to a varargs function. FUNCTION is the function in // which the call occurs--it's not the function we are calling. // VARARGS_TYPE is the type of the varargs parameter, a slice type. // PARAM_COUNT is the number of parameters of the function we are // calling; the last of these parameters will be the varargs // parameter. void Call_expression::lower_varargs(Gogo* gogo, Named_object* function, Statement_inserter* inserter, Type* varargs_type, size_t param_count, Slice_storage_escape_disp escape_disp) { if (this->varargs_are_lowered_) return; Location loc = this->location(); go_assert(param_count > 0); go_assert(varargs_type->is_slice_type()); size_t arg_count = this->args_ == NULL ? 0 : this->args_->size(); if (arg_count < param_count - 1) { // Not enough arguments; will be caught in check_types. return; } Expression_list* old_args = this->args_; Expression_list* new_args = new Expression_list(); bool push_empty_arg = false; if (old_args == NULL || old_args->empty()) { go_assert(param_count == 1); push_empty_arg = true; } else { Expression_list::const_iterator pa; int i = 1; for (pa = old_args->begin(); pa != old_args->end(); ++pa, ++i) { if (static_cast(i) == param_count) break; new_args->push_back(*pa); } // We have reached the varargs parameter. bool issued_error = false; if (pa == old_args->end()) push_empty_arg = true; else if (pa + 1 == old_args->end() && this->is_varargs_) new_args->push_back(*pa); else if (this->is_varargs_) { if ((*pa)->type()->is_slice_type()) this->report_error(_("too many arguments")); else { go_error_at(this->location(), _("invalid use of %<...%> with non-slice")); this->set_is_error(); } return; } else { Type* element_type = varargs_type->array_type()->element_type(); Expression_list* vals = new Expression_list; for (; pa != old_args->end(); ++pa, ++i) { // Check types here so that we get a better message. Type* patype = (*pa)->type(); Location paloc = (*pa)->location(); if (!this->check_argument_type(i, element_type, patype, paloc, issued_error)) continue; vals->push_back(*pa); } Slice_construction_expression* sce = Expression::make_slice_composite_literal(varargs_type, vals, loc); if (escape_disp == SLICE_STORAGE_DOES_NOT_ESCAPE) sce->set_storage_does_not_escape(); Expression* val = sce; gogo->lower_expression(function, inserter, &val); new_args->push_back(val); } } if (push_empty_arg) new_args->push_back(Expression::make_nil(loc)); // We can't return a new call expression here, because this one may // be referenced by Call_result expressions. FIXME. We can't // delete OLD_ARGS because we may have both a Call_expression and a // Builtin_call_expression which refer to them. FIXME. this->args_ = new_args; this->varargs_are_lowered_ = true; } // Flatten a call with multiple results into a temporary. Expression* Call_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { if (this->is_erroneous_call()) { go_assert(saw_errors()); return Expression::make_error(this->location()); } if (this->is_flattened_) return this; this->is_flattened_ = true; // Add temporary variables for all arguments that require type // conversion. Function_type* fntype = this->get_function_type(); if (fntype == NULL) { go_assert(saw_errors()); return this; } if (this->args_ != NULL && !this->args_->empty() && fntype->parameters() != NULL && !fntype->parameters()->empty()) { bool is_interface_method = this->fn_->interface_field_reference_expression() != NULL; Expression_list *args = new Expression_list(); Typed_identifier_list::const_iterator pp = fntype->parameters()->begin(); Expression_list::const_iterator pa = this->args_->begin(); if (!is_interface_method && fntype->is_method()) { // The receiver argument. args->push_back(*pa); ++pa; } for (; pa != this->args_->end(); ++pa, ++pp) { go_assert(pp != fntype->parameters()->end()); if (Type::are_identical(pp->type(), (*pa)->type(), Type::COMPARE_TAGS, NULL)) args->push_back(*pa); else { Location loc = (*pa)->location(); Expression* arg = *pa; if (!arg->is_multi_eval_safe()) { Temporary_statement *temp = Statement::make_temporary(NULL, arg, loc); inserter->insert(temp); arg = Expression::make_temporary_reference(temp, loc); } arg = Expression::convert_for_assignment(gogo, pp->type(), arg, loc); args->push_back(arg); } } delete this->args_; this->args_ = args; } // Lower to compiler intrinsic if possible. Func_expression* fe = this->fn_->func_expression(); if (!this->is_concurrent_ && !this->is_deferred_ && fe != NULL && (fe->named_object()->is_function_declaration() || fe->named_object()->is_function())) { Expression* ret = this->intrinsify(gogo, inserter); if (ret != NULL) return ret; } // Add an implicit conversion to a boolean type, if needed. See the // comment in Binary_expression::lower_array_comparison. if (this->is_equal_function_ && this->type_ != NULL && this->type_ != Type::lookup_bool_type()) return Expression::make_cast(this->type_, this, this->location()); return this; } // Lower a call to a compiler intrinsic if possible. // Returns NULL if it is not an intrinsic. Expression* Call_expression::intrinsify(Gogo* gogo, Statement_inserter* inserter) { Func_expression* fe = this->fn_->func_expression(); Named_object* no = fe->named_object(); std::string name = Gogo::unpack_hidden_name(no->name()); std::string package = (no->package() != NULL ? no->package()->pkgpath() : gogo->pkgpath()); bool is_method = ((no->is_function() && no->func_value()->is_method()) || (no->is_function_declaration() && no->func_declaration_value()->is_method())); Location loc = this->location(); Type* int_type = Type::lookup_integer_type("int"); Type* int32_type = Type::lookup_integer_type("int32"); Type* int64_type = Type::lookup_integer_type("int64"); Type* uint_type = Type::lookup_integer_type("uint"); Type* uint8_type = Type::lookup_integer_type("uint8"); Type* uint32_type = Type::lookup_integer_type("uint32"); Type* uint64_type = Type::lookup_integer_type("uint64"); Type* uintptr_type = Type::lookup_integer_type("uintptr"); Type* pointer_type = Type::make_pointer_type(Type::make_void_type()); int int_size = int_type->named_type()->real_type()->integer_type()->bits() / 8; int ptr_size = uintptr_type->named_type()->real_type()->integer_type()->bits() / 8; if (package == "sync/atomic") { if (is_method) return NULL; // sync/atomic functions and runtime/internal/atomic functions // are very similar. In order not to duplicate code, we just // redirect to the latter and let the code below to handle them. // Note: no StorePointer, SwapPointer, and CompareAndSwapPointer, // as they need write barriers. if (name == "LoadInt32") name = "Loadint32"; else if (name == "LoadInt64") name = "Loadint64"; else if (name == "LoadUint32") name = "Load"; else if (name == "LoadUint64") name = "Load64"; else if (name == "LoadUintptr") name = "Loaduintptr"; else if (name == "LoadPointer") name = "Loadp"; else if (name == "StoreInt32") name = "Storeint32"; else if (name == "StoreInt64") name = "Storeint64"; else if (name == "StoreUint32") name = "Store"; else if (name == "StoreUint64") name = "Store64"; else if (name == "StoreUintptr") name = "Storeuintptr"; else if (name == "AddInt32") name = "Xaddint32"; else if (name == "AddInt64") name = "Xaddint64"; else if (name == "AddUint32") name = "Xadd"; else if (name == "AddUint64") name = "Xadd64"; else if (name == "AddUintptr") name = "Xadduintptr"; else if (name == "SwapInt32") name = "Xchgint32"; else if (name == "SwapInt64") name = "Xchgint64"; else if (name == "SwapUint32") name = "Xchg"; else if (name == "SwapUint64") name = "Xchg64"; else if (name == "SwapUintptr") name = "Xchguintptr"; else if (name == "CompareAndSwapInt32") name = "Casint32"; else if (name == "CompareAndSwapInt64") name = "Casint64"; else if (name == "CompareAndSwapUint32") name = "Cas"; else if (name == "CompareAndSwapUint64") name = "Cas64"; else if (name == "CompareAndSwapUintptr") name = "Casuintptr"; else return NULL; package = "runtime/internal/atomic"; } if (package == "runtime/internal/sys") { if (is_method) return NULL; // runtime/internal/sys functions and math/bits functions // are very similar. In order not to duplicate code, we just // redirect to the latter and let the code below to handle them. if (name == "Bswap32") name = "ReverseBytes32"; else if (name == "Bswap64") name = "ReverseBytes64"; else if (name == "Ctz32") name = "TrailingZeros32"; else if (name == "Ctz64") name = "TrailingZeros64"; else return NULL; package = "math/bits"; } if (package == "runtime") { if (is_method) return NULL; // Handle a couple of special runtime functions. In the runtime // package, getcallerpc returns the PC of the caller, and // getcallersp returns the frame pointer of the caller. Implement // these by turning them into calls to GCC builtin functions. We // could implement them in normal code, but then we would have to // explicitly unwind the stack. These functions are intended to be // efficient. Note that this technique obviously only works for // direct calls, but that is the only way they are used. if (name == "getcallerpc" && (this->args_ == NULL || this->args_->size() == 0)) { Expression* arg = Expression::make_integer_ul(0, uint32_type, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_RETURN_ADDRESS, loc, 1, arg); // The builtin functions return void*, but the Go functions return uintptr. return Expression::make_cast(uintptr_type, call, loc); } else if (name == "getcallersp" && (this->args_ == NULL || this->args_->size() == 0)) { Expression* call = Runtime::make_call(Runtime::BUILTIN_DWARF_CFA, loc, 0); // The builtin functions return void*, but the Go functions return uintptr. return Expression::make_cast(uintptr_type, call, loc); } } else if (package == "math/bits") { if (is_method) return NULL; if ((name == "ReverseBytes16" || name == "ReverseBytes32" || name == "ReverseBytes64" || name == "ReverseBytes") && this->args_ != NULL && this->args_->size() == 1) { Runtime::Function code; if (name == "ReverseBytes16") code = Runtime::BUILTIN_BSWAP16; else if (name == "ReverseBytes32") code = Runtime::BUILTIN_BSWAP32; else if (name == "ReverseBytes64") code = Runtime::BUILTIN_BSWAP64; else if (name == "ReverseBytes") code = (int_size == 8 ? Runtime::BUILTIN_BSWAP64 : Runtime::BUILTIN_BSWAP32); else go_unreachable(); Expression* arg = this->args_->front(); Expression* call = Runtime::make_call(code, loc, 1, arg); if (name == "ReverseBytes") return Expression::make_cast(uint_type, call, loc); return call; } else if ((name == "TrailingZeros8" || name == "TrailingZeros16") && this->args_ != NULL && this->args_->size() == 1) { // GCC does not have a ctz8 or ctz16 intrinsic. We do // ctz32(0x100 | arg) or ctz32(0x10000 | arg). Expression* arg = this->args_->front(); arg = Expression::make_cast(uint32_type, arg, loc); unsigned long mask = (name == "TrailingZeros8" ? 0x100 : 0x10000); Expression* c = Expression::make_integer_ul(mask, uint32_type, loc); arg = Expression::make_binary(OPERATOR_OR, arg, c, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_CTZ, loc, 1, arg); return Expression::make_cast(int_type, call, loc); } else if ((name == "TrailingZeros32" || (name == "TrailingZeros" && int_size == 4)) && this->args_ != NULL && this->args_->size() == 1) { Expression* arg = this->args_->front(); if (!arg->is_multi_eval_safe()) { Temporary_statement* ts = Statement::make_temporary(uint32_type, arg, loc); inserter->insert(ts); arg = Expression::make_temporary_reference(ts, loc); } // arg == 0 ? 32 : __builtin_ctz(arg) Expression* zero = Expression::make_integer_ul(0, uint32_type, loc); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, arg, zero, loc); Expression* c32 = Expression::make_integer_ul(32, int_type, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_CTZ, loc, 1, arg->copy()); call = Expression::make_cast(int_type, call, loc); return Expression::make_conditional(cmp, c32, call, loc); } else if ((name == "TrailingZeros64" || (name == "TrailingZeros" && int_size == 8)) && this->args_ != NULL && this->args_->size() == 1) { Expression* arg = this->args_->front(); if (!arg->is_multi_eval_safe()) { Temporary_statement* ts = Statement::make_temporary(uint64_type, arg, loc); inserter->insert(ts); arg = Expression::make_temporary_reference(ts, loc); } // arg == 0 ? 64 : __builtin_ctzll(arg) Expression* zero = Expression::make_integer_ul(0, uint64_type, loc); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, arg, zero, loc); Expression* c64 = Expression::make_integer_ul(64, int_type, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_CTZLL, loc, 1, arg->copy()); call = Expression::make_cast(int_type, call, loc); return Expression::make_conditional(cmp, c64, call, loc); } else if ((name == "LeadingZeros8" || name == "LeadingZeros16" || name == "Len8" || name == "Len16") && this->args_ != NULL && this->args_->size() == 1) { // GCC does not have a clz8 ir clz16 intrinsic. We do // clz32(arg<<24 | 0xffffff) or clz32(arg<<16 | 0xffff). Expression* arg = this->args_->front(); arg = Expression::make_cast(uint32_type, arg, loc); unsigned long shift = ((name == "LeadingZeros8" || name == "Len8") ? 24 : 16); Expression* c = Expression::make_integer_ul(shift, uint32_type, loc); arg = Expression::make_binary(OPERATOR_LSHIFT, arg, c, loc); unsigned long mask = ((name == "LeadingZeros8" || name == "Len8") ? 0xffffff : 0xffff); c = Expression::make_integer_ul(mask, uint32_type, loc); arg = Expression::make_binary(OPERATOR_OR, arg, c, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_CLZ, loc, 1, arg); call = Expression::make_cast(int_type, call, loc); // len = width - clz if (name == "Len8") { c = Expression::make_integer_ul(8, int_type, loc); return Expression::make_binary(OPERATOR_MINUS, c, call, loc); } else if (name == "Len16") { c = Expression::make_integer_ul(16, int_type, loc); return Expression::make_binary(OPERATOR_MINUS, c, call, loc); } return call; } else if ((name == "LeadingZeros32" || name == "Len32" || ((name == "LeadingZeros" || name == "Len") && int_size == 4)) && this->args_ != NULL && this->args_->size() == 1) { Expression* arg = this->args_->front(); if (!arg->is_multi_eval_safe()) { Temporary_statement* ts = Statement::make_temporary(uint32_type, arg, loc); inserter->insert(ts); arg = Expression::make_temporary_reference(ts, loc); } // arg == 0 ? 32 : __builtin_clz(arg) Expression* zero = Expression::make_integer_ul(0, uint32_type, loc); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, arg, zero, loc); Expression* c32 = Expression::make_integer_ul(32, int_type, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_CLZ, loc, 1, arg->copy()); call = Expression::make_cast(int_type, call, loc); Expression* cond = Expression::make_conditional(cmp, c32, call, loc); // len = 32 - clz if (name == "Len32" || name == "Len") return Expression::make_binary(OPERATOR_MINUS, c32->copy(), cond, loc); return cond; } else if ((name == "LeadingZeros64" || name == "Len64" || ((name == "LeadingZeros" || name == "Len") && int_size == 8)) && this->args_ != NULL && this->args_->size() == 1) { Expression* arg = this->args_->front(); if (!arg->is_multi_eval_safe()) { Temporary_statement* ts = Statement::make_temporary(uint64_type, arg, loc); inserter->insert(ts); arg = Expression::make_temporary_reference(ts, loc); } // arg == 0 ? 64 : __builtin_clzll(arg) Expression* zero = Expression::make_integer_ul(0, uint64_type, loc); Expression* cmp = Expression::make_binary(OPERATOR_EQEQ, arg, zero, loc); Expression* c64 = Expression::make_integer_ul(64, int_type, loc); Expression* call = Runtime::make_call(Runtime::BUILTIN_CLZLL, loc, 1, arg->copy()); call = Expression::make_cast(int_type, call, loc); Expression* cond = Expression::make_conditional(cmp, c64, call, loc); // len = 64 - clz if (name == "Len64" || name == "Len") return Expression::make_binary(OPERATOR_MINUS, c64->copy(), cond, loc); return cond; } else if ((name == "OnesCount8" || name == "OnesCount16" || name == "OnesCount32" || name == "OnesCount64" || name == "OnesCount") && this->args_ != NULL && this->args_->size() == 1) { Runtime::Function code; if (name == "OnesCount64") code = Runtime::BUILTIN_POPCOUNTLL; else if (name == "OnesCount") code = (int_size == 8 ? Runtime::BUILTIN_POPCOUNTLL : Runtime::BUILTIN_POPCOUNT); else code = Runtime::BUILTIN_POPCOUNT; Expression* arg = this->args_->front(); Expression* call = Runtime::make_call(code, loc, 1, arg); return Expression::make_cast(int_type, call, loc); } } else if (package == "runtime/internal/atomic") { int memorder = __ATOMIC_SEQ_CST; if (is_method) { Function_type* ftype = (no->is_function() ? no->func_value()->type() : no->func_declaration_value()->type()); Type* rtype = ftype->receiver()->type()->deref(); go_assert(rtype->named_type() != NULL); const std::string& rname(rtype->named_type()->name()); if (rname == "Int32") { if (name == "Load") name = "LoadInt32"; else if (name == "Store") name = "Storeint32"; else if (name == "CompareAndSwap") name = "Casint32"; else if (name == "Swap") name = "Xchgint32"; else if (name == "Add") name = "Xaddint32"; else go_unreachable(); } else if (rname == "Int64") { if (name == "Load") name = "LoadInt64"; else if (name == "Store") name = "Storeint64"; else if (name == "CompareAndSwap") name = "Casint64"; else if (name == "Swap") name = "Xchgint64"; else if (name == "Add") name = "Xaddint64"; else go_unreachable(); } else if (rname == "Uint8") { if (name == "Load") name = "Load8"; else if (name == "Store") name = "Store8"; else if (name == "And") name = "And8"; else if (name == "Or") name = "Or8"; else go_unreachable(); } else if (rname == "Uint32") { if (name == "Load") name = "Load"; else if (name == "LoadAcquire") name = "LoadAcq"; else if (name == "Store") name = "Store"; else if (name == "CompareAndSwap") name = "Cas"; else if (name == "CompareAndSwapRelease") name = "CasRel"; else if (name == "Swap") name = "Xchg"; else if (name == "And") name = "And"; else if (name == "Or") name = "Or"; else if (name == "Add") name = "Xadd"; else go_unreachable(); } else if (rname == "Uint64") { if (name == "Load") name = "Load64"; else if (name == "Store") name = "Store64"; else if (name == "CompareAndSwap") name = "Cas64"; else if (name == "Swap") name = "Xchgt64"; else if (name == "Add") name = "Xadd64"; else go_unreachable(); } else if (rname == "Uintptr") { if (name == "Load") name = "Loaduintptr"; else if (name == "LoadAcquire") name = "Loadacquintptr"; else if (name == "Store") name = "Storeuintptr"; else if (name == "StoreRelease") name = "StoreReluintptr"; else if (name == "CompareAndSwap") name = "Casuintptr"; else if (name == "Swap") name = "Xchguintptr"; else if (name == "Add") name = "Xadduintptr"; else go_unreachable(); } else if (rname == "Float64") { // Needs unsafe type conversion. Don't intrinsify for now. return NULL; } else if (rname == "UnsafePointer") { if (name == "Load") name = "Loadp"; else if (name == "StoreNoWB") name = "StorepoWB"; else if (name == "CompareAndSwapNoWB") name = "Casp1"; else go_unreachable(); } else go_unreachable(); } if ((name == "Load" || name == "Load64" || name == "Loadint64" || name == "Loadp" || name == "Loaduint" || name == "Loaduintptr" || name == "LoadAcq" || name == "Loadint32" || name == "Load8") && this->args_ != NULL && this->args_->size() == 1) { if (int_size < 8 && (name == "Load64" || name == "Loadint64")) // On 32-bit architectures we need to check alignment. // Not intrinsify for now. return NULL; Runtime::Function code; Type* res_type; if (name == "Load") { code = Runtime::ATOMIC_LOAD_4; res_type = uint32_type; } else if (name == "Load64") { code = Runtime::ATOMIC_LOAD_8; res_type = uint64_type; } else if (name == "Loadint32") { code = Runtime::ATOMIC_LOAD_4; res_type = int32_type; } else if (name == "Loadint64") { code = Runtime::ATOMIC_LOAD_8; res_type = int64_type; } else if (name == "Loaduint") { code = (int_size == 8 ? Runtime::ATOMIC_LOAD_8 : Runtime::ATOMIC_LOAD_4); res_type = uint_type; } else if (name == "Loaduintptr") { code = (ptr_size == 8 ? Runtime::ATOMIC_LOAD_8 : Runtime::ATOMIC_LOAD_4); res_type = uintptr_type; } else if (name == "Loadp") { code = (ptr_size == 8 ? Runtime::ATOMIC_LOAD_8 : Runtime::ATOMIC_LOAD_4); res_type = pointer_type; } else if (name == "LoadAcq") { code = Runtime::ATOMIC_LOAD_4; res_type = uint32_type; memorder = __ATOMIC_ACQUIRE; } else if (name == "Load8") { code = Runtime::ATOMIC_LOAD_1; res_type = uint8_type; } else go_unreachable(); Expression* a1 = this->args_->front(); Expression* a2 = Expression::make_integer_ul(memorder, int32_type, loc); Expression* call = Runtime::make_call(code, loc, 2, a1, a2); return Expression::make_unsafe_cast(res_type, call, loc); } if ((name == "Store" || name == "Store64" || name == "StorepNoWB" || name == "Storeuintptr" || name == "StoreRel" || name == "Storeint32" || name == "Storeint64") && this->args_ != NULL && this->args_->size() == 2) { if (int_size < 8 && (name == "Store64" || name == "Storeint64")) return NULL; Runtime::Function code; Expression* a1 = this->args_->at(0); Expression* a2 = this->args_->at(1); if (name == "Store") code = Runtime::ATOMIC_STORE_4; else if (name == "Store64") code = Runtime::ATOMIC_STORE_8; else if (name == "Storeint32") code = Runtime::ATOMIC_STORE_4; else if (name == "Storeint64") code = Runtime::ATOMIC_STORE_8; else if (name == "Storeuintptr") code = (ptr_size == 8 ? Runtime::ATOMIC_STORE_8 : Runtime::ATOMIC_STORE_4); else if (name == "StorepNoWB") { code = (ptr_size == 8 ? Runtime::ATOMIC_STORE_8 : Runtime::ATOMIC_STORE_4); a2 = Expression::make_unsafe_cast(uintptr_type, a2, loc); a2 = Expression::make_cast(uint64_type, a2, loc); } else if (name == "StoreRel") { code = Runtime::ATOMIC_STORE_4; memorder = __ATOMIC_RELEASE; } else if (name == "Store8") code = Runtime::ATOMIC_STORE_1; else go_unreachable(); Expression* a3 = Expression::make_integer_ul(memorder, int32_type, loc); return Runtime::make_call(code, loc, 3, a1, a2, a3); } if ((name == "Xchg" || name == "Xchg64" || name == "Xchguintptr" || name == "Xchgint32" || name == "Xchgint64") && this->args_ != NULL && this->args_->size() == 2) { if (int_size < 8 && (name == "Xchg64" || name == "Xchgint64")) return NULL; Runtime::Function code; Type* res_type; if (name == "Xchg") { code = Runtime::ATOMIC_EXCHANGE_4; res_type = uint32_type; } else if (name == "Xchg64") { code = Runtime::ATOMIC_EXCHANGE_8; res_type = uint64_type; } else if (name == "Xchgint32") { code = Runtime::ATOMIC_EXCHANGE_4; res_type = int32_type; } else if (name == "Xchgint64") { code = Runtime::ATOMIC_EXCHANGE_8; res_type = int64_type; } else if (name == "Xchguintptr") { code = (ptr_size == 8 ? Runtime::ATOMIC_EXCHANGE_8 : Runtime::ATOMIC_EXCHANGE_4); res_type = uintptr_type; } else go_unreachable(); Expression* a1 = this->args_->at(0); Expression* a2 = this->args_->at(1); Expression* a3 = Expression::make_integer_ul(memorder, int32_type, loc); Expression* call = Runtime::make_call(code, loc, 3, a1, a2, a3); return Expression::make_cast(res_type, call, loc); } if ((name == "Cas" || name == "Cas64" || name == "Casuintptr" || name == "Casp1" || name == "CasRel" || name == "Casint32" || name == "Casint64") && this->args_ != NULL && this->args_->size() == 3) { if (int_size < 8 && (name == "Cas64" || name == "Casint64")) return NULL; Runtime::Function code; Expression* a1 = this->args_->at(0); // Builtin cas takes a pointer to the old value. // Store it in a temporary and take the address. Expression* a2 = this->args_->at(1); Temporary_statement* ts = Statement::make_temporary(NULL, a2, loc); inserter->insert(ts); a2 = Expression::make_temporary_reference(ts, loc); a2 = Expression::make_unary(OPERATOR_AND, a2, loc); Expression* a3 = this->args_->at(2); if (name == "Cas") code = Runtime::ATOMIC_COMPARE_EXCHANGE_4; else if (name == "Cas64") code = Runtime::ATOMIC_COMPARE_EXCHANGE_8; else if (name == "Casint32") code = Runtime::ATOMIC_COMPARE_EXCHANGE_4; else if (name == "Casint64") code = Runtime::ATOMIC_COMPARE_EXCHANGE_8; else if (name == "Casuintptr") code = (ptr_size == 8 ? Runtime::ATOMIC_COMPARE_EXCHANGE_8 : Runtime::ATOMIC_COMPARE_EXCHANGE_4); else if (name == "Casp1") { code = (ptr_size == 8 ? Runtime::ATOMIC_COMPARE_EXCHANGE_8 : Runtime::ATOMIC_COMPARE_EXCHANGE_4); a3 = Expression::make_unsafe_cast(uintptr_type, a3, loc); a3 = Expression::make_cast(uint64_type, a3, loc); } else if (name == "CasRel") { code = Runtime::ATOMIC_COMPARE_EXCHANGE_4; memorder = __ATOMIC_RELEASE; } else go_unreachable(); Expression* a4 = Expression::make_boolean(false, loc); Expression* a5 = Expression::make_integer_ul(memorder, int32_type, loc); Expression* a6 = Expression::make_integer_ul(__ATOMIC_RELAXED, int32_type, loc); return Runtime::make_call(code, loc, 6, a1, a2, a3, a4, a5, a6); } if ((name == "Xadd" || name == "Xadd64" || name == "Xaddint64" || name == "Xadduintptr" || name == "Xaddint32") && this->args_ != NULL && this->args_->size() == 2) { if (int_size < 8 && (name == "Xadd64" || name == "Xaddint64")) return NULL; Runtime::Function code; Type* res_type; if (name == "Xadd") { code = Runtime::ATOMIC_ADD_FETCH_4; res_type = uint32_type; } else if (name == "Xadd64") { code = Runtime::ATOMIC_ADD_FETCH_8; res_type = uint64_type; } else if (name == "Xaddint32") { code = Runtime::ATOMIC_ADD_FETCH_4; res_type = int32_type; } else if (name == "Xaddint64") { code = Runtime::ATOMIC_ADD_FETCH_8; res_type = int64_type; } else if (name == "Xadduintptr") { code = (ptr_size == 8 ? Runtime::ATOMIC_ADD_FETCH_8 : Runtime::ATOMIC_ADD_FETCH_4); res_type = uintptr_type; } else go_unreachable(); Expression* a1 = this->args_->at(0); Expression* a2 = this->args_->at(1); Expression* a3 = Expression::make_integer_ul(memorder, int32_type, loc); Expression* call = Runtime::make_call(code, loc, 3, a1, a2, a3); return Expression::make_cast(res_type, call, loc); } if ((name == "And8" || name == "Or8") && this->args_ != NULL && this->args_->size() == 2) { Runtime::Function code; if (name == "And8") code = Runtime::ATOMIC_AND_FETCH_1; else if (name == "Or8") code = Runtime::ATOMIC_OR_FETCH_1; else go_unreachable(); Expression* a1 = this->args_->at(0); Expression* a2 = this->args_->at(1); Expression* a3 = Expression::make_integer_ul(memorder, int32_type, loc); return Runtime::make_call(code, loc, 3, a1, a2, a3); } } else if (package == "internal/abi" || package == "bootstrap/internal/abi") // for bootstrapping gc { if (is_method) return NULL; if ((name == "FuncPCABI0" || name == "FuncPCABIInternal") && this->args_ != NULL && this->args_->size() == 1) { // We expect to see a conversion from the expression to "any". Expression* expr = this->args_->front(); Type_conversion_expression* tce = expr->conversion_expression(); if (tce != NULL) expr = tce->expr(); Func_expression* fe = expr->func_expression(); Interface_field_reference_expression* interface_method = expr->interface_field_reference_expression(); if (fe != NULL) { Named_object* no = fe->named_object(); Expression* ref = Expression::make_func_code_reference(no, loc); Type* uintptr_type = Type::lookup_integer_type("uintptr"); return Expression::make_cast(uintptr_type, ref, loc); } else if (interface_method != NULL) return interface_method->get_function(); else { expr = this->args_->front(); go_assert(expr->type()->interface_type() != NULL && expr->type()->interface_type()->is_empty()); expr = Expression::make_interface_info(expr, INTERFACE_INFO_OBJECT, loc); // Trust that this is a function type, which means that // it is a direct iface type and we can use EXPR // directly. The backend representation of this // function is a pointer to a struct whose first field // is the actual function to call. Type* pvoid = Type::make_pointer_type(Type::make_void_type()); Type* pfntype = Type::make_pointer_type(pvoid); Expression* ref = make_unsafe_cast(pfntype, expr, loc); return Expression::make_dereference(ref, NIL_CHECK_NOT_NEEDED, loc); } } } return NULL; } // Make implicit type conversions explicit. void Call_expression::do_add_conversions() { // Skip call that requires a thunk. We generate conversions inside the thunk. if (this->is_concurrent_ || this->is_deferred_) return; if (this->args_ == NULL || this->args_->empty()) return; Function_type* fntype = this->get_function_type(); if (fntype == NULL) { go_assert(saw_errors()); return; } if (fntype->parameters() == NULL || fntype->parameters()->empty()) return; Location loc = this->location(); Expression_list::iterator pa = this->args_->begin(); Typed_identifier_list::const_iterator pp = fntype->parameters()->begin(); bool is_interface_method = this->fn_->interface_field_reference_expression() != NULL; size_t argcount = this->args_->size(); if (!is_interface_method && fntype->is_method()) { // Skip the receiver argument, which cannot be interface. pa++; argcount--; } if (argcount != fntype->parameters()->size()) { go_assert(saw_errors()); return; } for (; pa != this->args_->end(); ++pa, ++pp) { Type* pt = pp->type(); if (!Type::are_identical(pt, (*pa)->type(), 0, NULL) && pt->interface_type() != NULL) *pa = Expression::make_cast(pt, *pa, loc); } } // Get the function type. This can return NULL in error cases. Function_type* Call_expression::get_function_type() const { return this->fn_->type()->function_type(); } // Return the number of values which this call will return. size_t Call_expression::result_count() const { const Function_type* fntype = this->get_function_type(); if (fntype == NULL) return 0; if (fntype->results() == NULL) return 0; return fntype->results()->size(); } // Return the temporary that holds the result for a call with multiple // results. Temporary_statement* Call_expression::results() const { if (this->call_temp_ == NULL) { go_assert(saw_errors()); return NULL; } return this->call_temp_; } // Set the number of results expected from a call expression. void Call_expression::set_expected_result_count(size_t count) { go_assert(this->expected_result_count_ == 0); this->expected_result_count_ = count; } // Return whether this is a call to the predeclared function recover. bool Call_expression::is_recover_call() const { return this->do_is_recover_call(); } // Set the argument to the recover function. void Call_expression::set_recover_arg(Expression* arg) { this->do_set_recover_arg(arg); } // Virtual functions also implemented by Builtin_call_expression. bool Call_expression::do_is_recover_call() const { return false; } void Call_expression::do_set_recover_arg(Expression*) { go_unreachable(); } // We have found an error with this call expression; return true if // we should report it. bool Call_expression::issue_error() { if (this->issued_error_) return false; else { this->issued_error_ = true; return true; } } // Whether or not this call contains errors, either in the call or the // arguments to the call. bool Call_expression::is_erroneous_call() { if (this->is_error_expression() || this->fn()->is_error_expression()) return true; if (this->args() == NULL) return false; for (Expression_list::iterator pa = this->args()->begin(); pa != this->args()->end(); ++pa) { if ((*pa)->type()->is_error_type() || (*pa)->is_error_expression()) return true; } return false; } // Get the type. Type* Call_expression::do_type() { if (this->is_error_expression()) return Type::make_error_type(); if (this->type_ != NULL) return this->type_; Type* ret; Function_type* fntype = this->get_function_type(); if (fntype == NULL) return Type::make_error_type(); const Typed_identifier_list* results = fntype->results(); if (results == NULL) ret = Type::make_void_type(); else if (results->size() == 1) ret = results->begin()->type(); else ret = Type::make_call_multiple_result_type(); this->type_ = ret; return this->type_; } // Determine types for a call expression. We can use the function // parameter types to set the types of the arguments. void Call_expression::do_determine_type(const Type_context* context) { if (!this->determining_types()) return; this->fn_->determine_type_no_context(); Function_type* fntype = this->get_function_type(); const Typed_identifier_list* parameters = NULL; if (fntype != NULL) parameters = fntype->parameters(); if (this->args_ != NULL) { Typed_identifier_list::const_iterator pt; if (parameters != NULL) pt = parameters->begin(); bool first = true; for (Expression_list::const_iterator pa = this->args_->begin(); pa != this->args_->end(); ++pa) { if (first) { first = false; // If this is a method, the first argument is the // receiver. if (fntype != NULL && fntype->is_method()) { Type* rtype = fntype->receiver()->type(); // The receiver is always passed as a pointer. if (rtype->points_to() == NULL) rtype = Type::make_pointer_type(rtype); Type_context subcontext(rtype, false); (*pa)->determine_type(&subcontext); continue; } } if (parameters != NULL && pt != parameters->end()) { Type_context subcontext(pt->type(), false); (*pa)->determine_type(&subcontext); ++pt; } else (*pa)->determine_type_no_context(); } } // If this is a call to a generated equality function, we determine // the type based on the context. See the comment in // Binary_expression::lower_array_comparison. if (this->is_equal_function_ && !context->may_be_abstract && context->type != NULL && context->type->is_boolean_type() && context->type != Type::lookup_bool_type()) { go_assert(this->type_ == NULL || this->type_ == Type::lookup_bool_type() || this->type_ == context->type || this->type_->is_error()); this->type_ = context->type; } } // Called when determining types for a Call_expression. Return true // if we should go ahead, false if they have already been determined. bool Call_expression::determining_types() { if (this->types_are_determined_) return false; else { this->types_are_determined_ = true; return true; } } // Check types for parameter I. bool Call_expression::check_argument_type(int i, const Type* parameter_type, const Type* argument_type, Location argument_location, bool issued_error) { std::string reason; if (!Type::are_assignable(parameter_type, argument_type, &reason)) { if (!issued_error) { if (reason.empty()) go_error_at(argument_location, "argument %d has incompatible type", i); else go_error_at(argument_location, "argument %d has incompatible type (%s)", i, reason.c_str()); } this->set_is_error(); return false; } return true; } // Check types. void Call_expression::do_check_types(Gogo*) { if (this->classification() == EXPRESSION_ERROR) return; Function_type* fntype = this->get_function_type(); if (fntype == NULL) { if (!this->fn_->type()->is_error()) this->report_error(_("expected function")); return; } if (this->expected_result_count_ != 0 && this->expected_result_count_ != this->result_count()) { if (this->issue_error()) this->report_error(_("function result count mismatch")); this->set_is_error(); return; } bool is_method = fntype->is_method(); if (is_method) { go_assert(this->args_ != NULL && !this->args_->empty()); Type* rtype = fntype->receiver()->type(); Expression* first_arg = this->args_->front(); // We dereference the values since receivers are always passed // as pointers. std::string reason; if (!Type::are_assignable(rtype->deref(), first_arg->type()->deref(), &reason)) { if (reason.empty()) this->report_error(_("incompatible type for receiver")); else { go_error_at(this->location(), "incompatible type for receiver (%s)", reason.c_str()); this->set_is_error(); } } } // Note that varargs was handled by the lower_varargs() method, so // we don't have to worry about it here unless something is wrong. if (this->is_varargs_ && !this->varargs_are_lowered_) { if (!fntype->is_varargs()) { go_error_at(this->location(), _("invalid use of %<...%> calling non-variadic function")); this->set_is_error(); return; } } const Typed_identifier_list* parameters = fntype->parameters(); if (this->args_ == NULL || this->args_->size() == 0) { if (parameters != NULL && !parameters->empty()) this->report_error(_("not enough arguments")); } else if (parameters == NULL) { if (!is_method || this->args_->size() > 1) this->report_error(_("too many arguments")); } else if (this->args_->size() == 1 && this->args_->front()->call_expression() != NULL && this->args_->front()->call_expression()->result_count() > 1) { // This is F(G()) when G returns more than one result. If the // results can be matched to parameters, it would have been // lowered in do_lower. If we get here we know there is a // mismatch. if (this->args_->front()->call_expression()->result_count() < parameters->size()) this->report_error(_("not enough arguments")); else this->report_error(_("too many arguments")); } else { int i = 0; Expression_list::const_iterator pa = this->args_->begin(); if (is_method) ++pa; for (Typed_identifier_list::const_iterator pt = parameters->begin(); pt != parameters->end(); ++pt, ++pa, ++i) { if (pa == this->args_->end()) { this->report_error(_("not enough arguments")); return; } this->check_argument_type(i + 1, pt->type(), (*pa)->type(), (*pa)->location(), false); } if (pa != this->args_->end()) this->report_error(_("too many arguments")); } } Expression* Call_expression::do_copy() { Call_expression* call = Expression::make_call(this->fn_->copy(), (this->args_ == NULL ? NULL : this->args_->copy()), this->is_varargs_, this->location()); if (this->varargs_are_lowered_) call->set_varargs_are_lowered(); if (this->is_deferred_) call->set_is_deferred(); if (this->is_concurrent_) call->set_is_concurrent(); return call; } // Return whether we have to use a temporary variable to ensure that // we evaluate this call expression in order. If the call returns no // results then it will inevitably be executed last. bool Call_expression::do_must_eval_in_order() const { return this->result_count() > 0; } // Get the function and the first argument to use when calling an // interface method. Expression* Call_expression::interface_method_function( Interface_field_reference_expression* interface_method, Expression** first_arg_ptr, Location location) { Expression* object = interface_method->get_underlying_object(); Type* unsafe_ptr_type = Type::make_pointer_type(Type::make_void_type()); *first_arg_ptr = Expression::make_unsafe_cast(unsafe_ptr_type, object, location); return interface_method->get_function(); } // Build the call expression. Bexpression* Call_expression::do_get_backend(Translate_context* context) { Location location = this->location(); if (this->call_ != NULL) { // If the call returns multiple results, make a new reference to // the temporary. if (this->call_temp_ != NULL) { Expression* ref = Expression::make_temporary_reference(this->call_temp_, location); return ref->get_backend(context); } return this->call_; } Function_type* fntype = this->get_function_type(); if (fntype == NULL) return context->backend()->error_expression(); if (this->fn_->is_error_expression()) return context->backend()->error_expression(); Gogo* gogo = context->gogo(); Func_expression* func = this->fn_->func_expression(); Interface_field_reference_expression* interface_method = this->fn_->interface_field_reference_expression(); const bool has_closure = func != NULL && func->closure() != NULL; const bool is_interface_method = interface_method != NULL; bool has_closure_arg; if (has_closure) has_closure_arg = true; else if (func != NULL) has_closure_arg = false; else if (is_interface_method) has_closure_arg = false; else has_closure_arg = true; Expression* first_arg = NULL; if (!is_interface_method && fntype->is_method()) { first_arg = this->args_->front(); if (first_arg->type()->points_to() == NULL && first_arg->type()->is_direct_iface_type()) first_arg = Expression::unpack_direct_iface(first_arg, first_arg->location()); } int nargs; std::vector fn_args; if (this->args_ == NULL || this->args_->empty()) { nargs = is_interface_method ? 1 : 0; if (nargs > 0) fn_args.resize(1); } else if (fntype->parameters() == NULL || fntype->parameters()->empty()) { // Passing a receiver parameter. go_assert(!is_interface_method && fntype->is_method() && this->args_->size() == 1); nargs = 1; fn_args.resize(1); fn_args[0] = first_arg->get_backend(context); } else { const Typed_identifier_list* params = fntype->parameters(); nargs = this->args_->size(); int i = is_interface_method ? 1 : 0; nargs += i; fn_args.resize(nargs); Typed_identifier_list::const_iterator pp = params->begin(); Expression_list::const_iterator pe = this->args_->begin(); if (!is_interface_method && fntype->is_method()) { fn_args[i] = first_arg->get_backend(context); ++pe; ++i; } for (; pe != this->args_->end(); ++pe, ++pp, ++i) { go_assert(pp != params->end()); Expression* arg = Expression::convert_for_assignment(gogo, pp->type(), *pe, location); fn_args[i] = arg->get_backend(context); } go_assert(pp == params->end()); go_assert(i == nargs); } Expression* fn; Expression* closure = NULL; if (func != NULL) { Named_object* no = func->named_object(); fn = Expression::make_func_code_reference(no, location); if (has_closure) closure = func->closure(); } else if (!is_interface_method) { closure = this->fn_; // The backend representation of this function type is a pointer // to a struct whose first field is the actual function to call. Type* pfntype = Type::make_pointer_type( Type::make_pointer_type(Type::make_void_type())); fn = Expression::make_unsafe_cast(pfntype, this->fn_, location); fn = Expression::make_dereference(fn, NIL_CHECK_NOT_NEEDED, location); } else { Expression* arg0; fn = this->interface_method_function(interface_method, &arg0, location); fn_args[0] = arg0->get_backend(context); } Bexpression* bclosure = NULL; if (has_closure_arg) bclosure = closure->get_backend(context); else go_assert(closure == NULL); Bexpression* bfn = fn->get_backend(context); // When not calling a named function directly, use a type conversion // in case the type of the function is a recursive type which refers // to itself. We don't do this for an interface method because 1) // an interface method never refers to itself, so we always have a // function type here; 2) we pass an extra first argument to an // interface method, so fntype is not correct. if (func == NULL && !is_interface_method) { Btype* bft = fntype->get_backend_fntype(gogo); bfn = gogo->backend()->convert_expression(bft, bfn, location); } Bfunction* bfunction = NULL; if (context->function()) bfunction = context->function()->func_value()->get_decl(); Bexpression* call = gogo->backend()->call_expression(bfunction, bfn, fn_args, bclosure, location); if (this->call_temp_ != NULL) { // This case occurs when the call returns multiple results. Expression* ref = Expression::make_temporary_reference(this->call_temp_, location); Bexpression* bref = ref->get_backend(context); Bstatement* bassn = gogo->backend()->assignment_statement(bfunction, bref, call, location); ref = Expression::make_temporary_reference(this->call_temp_, location); this->call_ = ref->get_backend(context); return gogo->backend()->compound_expression(bassn, this->call_, location); } this->call_ = call; return this->call_; } // The cost of inlining a call expression. int Call_expression::do_inlining_cost() const { Func_expression* fn = this->fn_->func_expression(); // FIXME: We don't yet support all kinds of calls. if (fn != NULL && fn->closure() != NULL) return 0x100000; if (this->fn_->interface_field_reference_expression()) return 0x100000; if (this->get_function_type()->is_method()) return 0x100000; return 5; } // Export a call expression. void Call_expression::do_export(Export_function_body* efb) const { bool simple_call = (this->fn_->func_expression() != NULL); if (!simple_call) efb->write_c_string("("); this->fn_->export_expression(efb); if (!simple_call) efb->write_c_string(")"); this->export_arguments(efb); } // Export call expression arguments. void Call_expression::export_arguments(Export_function_body* efb) const { efb->write_c_string("("); if (this->args_ != NULL && !this->args_->empty()) { Expression_list::const_iterator pa = this->args_->begin(); (*pa)->export_expression(efb); for (pa++; pa != this->args_->end(); pa++) { efb->write_c_string(", "); (*pa)->export_expression(efb); } if (this->is_varargs_) efb->write_c_string("..."); } efb->write_c_string(")"); } // Dump ast representation for a call expression. void Call_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { this->fn_->dump_expression(ast_dump_context); ast_dump_context->ostream() << "("; if (args_ != NULL) ast_dump_context->dump_expression_list(this->args_); ast_dump_context->ostream() << ") "; } // Make a call expression. Call_expression* Expression::make_call(Expression* fn, Expression_list* args, bool is_varargs, Location location) { return new Call_expression(fn, args, is_varargs, location); } // Class Call_result_expression. // Traverse a call result. int Call_result_expression::do_traverse(Traverse* traverse) { if (traverse->remember_expression(this->call_)) { // We have already traversed the call expression. return TRAVERSE_CONTINUE; } return Expression::traverse(&this->call_, traverse); } // Get the type. Type* Call_result_expression::do_type() { if (this->classification() == EXPRESSION_ERROR) return Type::make_error_type(); // THIS->CALL_ can be replaced with a temporary reference due to // Call_expression::do_must_eval_in_order when there is an error. Call_expression* ce = this->call_->call_expression(); if (ce == NULL) { this->set_is_error(); return Type::make_error_type(); } Function_type* fntype = ce->get_function_type(); if (fntype == NULL) { if (ce->issue_error()) { if (!ce->fn()->type()->is_error()) this->report_error(_("expected function")); } this->set_is_error(); return Type::make_error_type(); } const Typed_identifier_list* results = fntype->results(); if (results == NULL || results->size() < 2) { if (ce->issue_error()) this->report_error(_("number of results does not match " "number of values")); return Type::make_error_type(); } Typed_identifier_list::const_iterator pr = results->begin(); for (unsigned int i = 0; i < this->index_; ++i) { if (pr == results->end()) break; ++pr; } if (pr == results->end()) { if (ce->issue_error()) this->report_error(_("number of results does not match " "number of values")); return Type::make_error_type(); } return pr->type(); } // Check the type. Just make sure that we trigger the warning in // do_type. void Call_result_expression::do_check_types(Gogo*) { this->type(); } // Determine the type. We have nothing to do here, but the 0 result // needs to pass down to the caller. void Call_result_expression::do_determine_type(const Type_context*) { this->call_->determine_type_no_context(); } // Return the backend representation. We just refer to the temporary set by the // call expression. We don't do this at lowering time because it makes it // hard to evaluate the call at the right time. Bexpression* Call_result_expression::do_get_backend(Translate_context* context) { Call_expression* ce = this->call_->call_expression(); if (ce == NULL) { go_assert(this->call_->is_error_expression()); return context->backend()->error_expression(); } Temporary_statement* ts = ce->results(); if (ts == NULL) { go_assert(saw_errors()); return context->backend()->error_expression(); } Expression* ref = Expression::make_temporary_reference(ts, this->location()); ref = Expression::make_field_reference(ref, this->index_, this->location()); return ref->get_backend(context); } // Dump ast representation for a call result expression. void Call_result_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { // FIXME: Wouldn't it be better if the call is assigned to a temporary // (struct) and the fields are referenced instead. ast_dump_context->ostream() << this->index_ << "@("; ast_dump_context->dump_expression(this->call_); ast_dump_context->ostream() << ")"; } // Make a reference to a single result of a call which returns // multiple results. Expression* Expression::make_call_result(Call_expression* call, unsigned int index) { return new Call_result_expression(call, index); } // Class Index_expression. // Traversal. int Index_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->left_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->start_, traverse) == TRAVERSE_EXIT || (this->end_ != NULL && Expression::traverse(&this->end_, traverse) == TRAVERSE_EXIT) || (this->cap_ != NULL && Expression::traverse(&this->cap_, traverse) == TRAVERSE_EXIT)) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Lower an index expression. This converts the generic index // expression into an array index, a string index, or a map index. Expression* Index_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int) { Location location = this->location(); Expression* left = this->left_; Expression* start = this->start_; Expression* end = this->end_; Expression* cap = this->cap_; Type* type = left->type(); if (type->is_error()) { go_assert(saw_errors()); return Expression::make_error(location); } else if (left->is_type_expression()) { go_error_at(location, "attempt to index type expression"); return Expression::make_error(location); } else if (type->array_type() != NULL) return Expression::make_array_index(left, start, end, cap, location); else if (type->points_to() != NULL && type->points_to()->array_type() != NULL && !type->points_to()->is_slice_type()) { Expression* deref = Expression::make_dereference(left, NIL_CHECK_DEFAULT, location); // For an ordinary index into the array, the pointer will be // dereferenced. For a slice it will not--the resulting slice // will simply reuse the pointer, which is incorrect if that // pointer is nil. if (end != NULL || cap != NULL) deref->issue_nil_check(); return Expression::make_array_index(deref, start, end, cap, location); } else if (type->is_string_type()) { if (cap != NULL) { go_error_at(location, "invalid 3-index slice of string"); return Expression::make_error(location); } return Expression::make_string_index(left, start, end, location); } else if (type->map_type() != NULL) { if (end != NULL || cap != NULL) { go_error_at(location, "invalid slice of map"); return Expression::make_error(location); } return Expression::make_map_index(left, start, location); } else if (cap != NULL) { go_error_at(location, "invalid 3-index slice of object that is not a slice"); return Expression::make_error(location); } else if (end != NULL) { go_error_at(location, ("attempt to slice object that is not " "array, slice, or string")); return Expression::make_error(location); } else { go_error_at(location, ("attempt to index object that is not " "array, slice, string, or map")); return Expression::make_error(location); } } // Write an indexed expression // (expr[expr:expr:expr], expr[expr:expr] or expr[expr]) to a dump context. void Index_expression::dump_index_expression(Ast_dump_context* ast_dump_context, const Expression* expr, const Expression* start, const Expression* end, const Expression* cap) { expr->dump_expression(ast_dump_context); ast_dump_context->ostream() << "["; start->dump_expression(ast_dump_context); if (end != NULL) { ast_dump_context->ostream() << ":"; end->dump_expression(ast_dump_context); } if (cap != NULL) { ast_dump_context->ostream() << ":"; cap->dump_expression(ast_dump_context); } ast_dump_context->ostream() << "]"; } // Dump ast representation for an index expression. void Index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { Index_expression::dump_index_expression(ast_dump_context, this->left_, this->start_, this->end_, this->cap_); } // Make an index expression. Expression* Expression::make_index(Expression* left, Expression* start, Expression* end, Expression* cap, Location location) { return new Index_expression(left, start, end, cap, location); } // Class Array_index_expression. // Array index traversal. int Array_index_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->array_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (Expression::traverse(&this->start_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (this->end_ != NULL) { if (Expression::traverse(&this->end_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } if (this->cap_ != NULL) { if (Expression::traverse(&this->cap_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } return TRAVERSE_CONTINUE; } // Return the type of an array index. Type* Array_index_expression::do_type() { if (this->type_ == NULL) { Array_type* type = this->array_->type()->array_type(); if (type == NULL) this->type_ = Type::make_error_type(); else if (this->end_ == NULL) this->type_ = type->element_type(); else if (type->is_slice_type()) { // A slice of a slice has the same type as the original // slice. this->type_ = this->array_->type()->deref(); } else { // A slice of an array is a slice. this->type_ = Type::make_array_type(type->element_type(), NULL); } } return this->type_; } // Set the type of an array index. void Array_index_expression::do_determine_type(const Type_context*) { this->array_->determine_type_no_context(); Type_context index_context(Type::lookup_integer_type("int"), false); this->start_->determine_type(&index_context); if (this->end_ != NULL) this->end_->determine_type(&index_context); if (this->cap_ != NULL) this->cap_->determine_type(&index_context); } // Check types of an array index. void Array_index_expression::do_check_types(Gogo*) { Numeric_constant nc; unsigned long v; if (this->start_->type()->integer_type() == NULL && !this->start_->type()->is_error() && (!this->start_->type()->is_abstract() || !this->start_->numeric_constant_value(&nc) || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) this->report_error(_("index must be integer")); if (this->end_ != NULL && this->end_->type()->integer_type() == NULL && !this->end_->type()->is_error() && !this->end_->is_nil_expression() && !this->end_->is_error_expression() && (!this->end_->type()->is_abstract() || !this->end_->numeric_constant_value(&nc) || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) this->report_error(_("slice end must be integer")); if (this->cap_ != NULL && this->cap_->type()->integer_type() == NULL && !this->cap_->type()->is_error() && !this->cap_->is_nil_expression() && !this->cap_->is_error_expression() && (!this->cap_->type()->is_abstract() || !this->cap_->numeric_constant_value(&nc) || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) this->report_error(_("slice capacity must be integer")); Array_type* array_type = this->array_->type()->array_type(); if (array_type == NULL) { go_assert(this->array_->type()->is_error()); this->set_is_error(); return; } unsigned int int_bits = Type::lookup_integer_type("int")->integer_type()->bits(); Numeric_constant lvalnc; mpz_t lval; bool lval_valid = (array_type->length() != NULL && array_type->length()->numeric_constant_value(&lvalnc) && lvalnc.to_int(&lval)); Numeric_constant inc; mpz_t ival; bool ival_valid = false; if (this->start_->numeric_constant_value(&inc) && inc.to_int(&ival)) { ival_valid = true; if (mpz_sgn(ival) < 0 || mpz_sizeinbase(ival, 2) >= int_bits || (lval_valid && (this->end_ == NULL ? mpz_cmp(ival, lval) >= 0 : mpz_cmp(ival, lval) > 0))) { go_error_at(this->start_->location(), "array index out of bounds"); this->set_is_error(); } } if (this->end_ != NULL && !this->end_->is_nil_expression()) { Numeric_constant enc; mpz_t eval; bool eval_valid = false; if (this->end_->numeric_constant_value(&enc) && enc.to_int(&eval)) { eval_valid = true; if (mpz_sgn(eval) < 0 || mpz_sizeinbase(eval, 2) >= int_bits || (lval_valid && mpz_cmp(eval, lval) > 0)) { go_error_at(this->end_->location(), "array index out of bounds"); this->set_is_error(); } else if (ival_valid && mpz_cmp(ival, eval) > 0) this->report_error(_("inverted slice range")); } Numeric_constant cnc; mpz_t cval; if (this->cap_ != NULL && this->cap_->numeric_constant_value(&cnc) && cnc.to_int(&cval)) { if (mpz_sgn(cval) < 0 || mpz_sizeinbase(cval, 2) >= int_bits || (lval_valid && mpz_cmp(cval, lval) > 0)) { go_error_at(this->cap_->location(), "array index out of bounds"); this->set_is_error(); } else if (ival_valid && mpz_cmp(ival, cval) > 0) { go_error_at(this->cap_->location(), "invalid slice index: capacity less than start"); this->set_is_error(); } else if (eval_valid && mpz_cmp(eval, cval) > 0) { go_error_at(this->cap_->location(), "invalid slice index: capacity less than length"); this->set_is_error(); } mpz_clear(cval); } if (eval_valid) mpz_clear(eval); } if (ival_valid) mpz_clear(ival); if (lval_valid) mpz_clear(lval); // A slice of an array requires an addressable array. A slice of a // slice is always possible. if (this->end_ != NULL && !array_type->is_slice_type()) { if (!this->array_->is_addressable()) this->report_error(_("slice of unaddressable value")); else // Set the array address taken but not escape. The escape // analysis will make it escape to heap when needed. this->array_->address_taken(false); } } // The subexpressions of an array index must be evaluated in order. // If this is indexing into an array, rather than a slice, then only // the index should be evaluated. Since this is called for values on // the left hand side of an assigment, evaluating the array, meaning // copying the array, will cause a different array to be modified. bool Array_index_expression::do_must_eval_subexpressions_in_order( int* skip) const { *skip = this->array_->type()->is_slice_type() ? 0 : 1; return true; } // Flatten array indexing: add temporary variables and bounds checks. Expression* Array_index_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { if (this->is_flattened_) return this; this->is_flattened_ = true; Location loc = this->location(); if (this->is_error_expression()) return Expression::make_error(loc); Expression* array = this->array_; Expression* start = this->start_; Expression* end = this->end_; Expression* cap = this->cap_; if (array->is_error_expression() || array->type()->is_error_type() || start->is_error_expression() || start->type()->is_error_type() || (end != NULL && (end->is_error_expression() || end->type()->is_error_type())) || (cap != NULL && (cap->is_error_expression() || cap->type()->is_error_type()))) { go_assert(saw_errors()); return Expression::make_error(loc); } Array_type* array_type = this->array_->type()->array_type(); if (array_type == NULL) { go_assert(saw_errors()); return Expression::make_error(loc); } Temporary_statement* temp; if (array_type->is_slice_type() && !array->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, array, loc); inserter->insert(temp); this->array_ = Expression::make_temporary_reference(temp, loc); array = this->array_; } if (!start->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, start, loc); inserter->insert(temp); this->start_ = Expression::make_temporary_reference(temp, loc); start = this->start_; } if (end != NULL && !end->is_nil_expression() && !end->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, end, loc); inserter->insert(temp); this->end_ = Expression::make_temporary_reference(temp, loc); end = this->end_; } if (cap != NULL && !cap->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, cap, loc); inserter->insert(temp); this->cap_ = Expression::make_temporary_reference(temp, loc); cap = this->cap_; } if (!this->needs_bounds_check_) return this; Expression* len; if (!array_type->is_slice_type()) { len = array_type->get_length(gogo, this->array_); go_assert(len->is_constant()); } else { len = array_type->get_length(gogo, this->array_->copy()); temp = Statement::make_temporary(NULL, len, loc); inserter->insert(temp); len = Expression::make_temporary_reference(temp, loc); } Expression* scap = NULL; if (array_type->is_slice_type()) { scap = array_type->get_capacity(gogo, this->array_->copy()); temp = Statement::make_temporary(NULL, scap, loc); inserter->insert(temp); scap = Expression::make_temporary_reference(temp, loc); } // The order of bounds checks here matches the order used by the gc // compiler, as tested by issue30116[u].go. if (cap != NULL) { if (array_type->is_slice_type()) Expression::check_bounds(cap, OPERATOR_LE, scap, Runtime::PANIC_SLICE3_ACAP, Runtime::PANIC_SLICE3_ACAP_U, Runtime::PANIC_EXTEND_SLICE3_ACAP, Runtime::PANIC_EXTEND_SLICE3_ACAP_U, inserter, loc); else Expression::check_bounds(cap, OPERATOR_LE, len, Runtime::PANIC_SLICE3_ALEN, Runtime::PANIC_SLICE3_ALEN_U, Runtime::PANIC_EXTEND_SLICE3_ALEN, Runtime::PANIC_EXTEND_SLICE3_ALEN_U, inserter, loc); Expression* start_bound = cap; if (end != NULL && !end->is_nil_expression()) { Expression::check_bounds(end, OPERATOR_LE, cap, Runtime::PANIC_SLICE3_B, Runtime::PANIC_SLICE3_B_U, Runtime::PANIC_EXTEND_SLICE3_B, Runtime::PANIC_EXTEND_SLICE3_B_U, inserter, loc); start_bound = end; } Expression::check_bounds(start, OPERATOR_LE, start_bound, Runtime::PANIC_SLICE3_C, Runtime::PANIC_SLICE3_C_U, Runtime::PANIC_EXTEND_SLICE3_C, Runtime::PANIC_EXTEND_SLICE3_C_U, inserter, loc); } else if (end != NULL && !end->is_nil_expression()) { if (array_type->is_slice_type()) Expression::check_bounds(end, OPERATOR_LE, scap, Runtime::PANIC_SLICE_ACAP, Runtime::PANIC_SLICE_ACAP_U, Runtime::PANIC_EXTEND_SLICE_ACAP, Runtime::PANIC_EXTEND_SLICE_ACAP_U, inserter, loc); else Expression::check_bounds(end, OPERATOR_LE, len, Runtime::PANIC_SLICE_ALEN, Runtime::PANIC_SLICE_ALEN_U, Runtime::PANIC_EXTEND_SLICE_ALEN, Runtime::PANIC_EXTEND_SLICE_ALEN_U, inserter, loc); Expression::check_bounds(start, OPERATOR_LE, end, Runtime::PANIC_SLICE_B, Runtime::PANIC_SLICE_B_U, Runtime::PANIC_EXTEND_SLICE_B, Runtime::PANIC_EXTEND_SLICE_B_U, inserter, loc); } else if (end != NULL) { Expression* start_bound; if (array_type->is_slice_type()) start_bound = scap; else start_bound = len; Expression::check_bounds(start, OPERATOR_LE, start_bound, Runtime::PANIC_SLICE_B, Runtime::PANIC_SLICE_B_U, Runtime::PANIC_EXTEND_SLICE_B, Runtime::PANIC_EXTEND_SLICE_B_U, inserter, loc); } else Expression::check_bounds(start, OPERATOR_LT, len, Runtime::PANIC_INDEX, Runtime::PANIC_INDEX_U, Runtime::PANIC_EXTEND_INDEX, Runtime::PANIC_EXTEND_INDEX_U, inserter, loc); return this; } // Return whether this expression is addressable. bool Array_index_expression::do_is_addressable() const { // A slice expression is not addressable. if (this->end_ != NULL) return false; // An index into a slice is addressable. if (this->array_->type()->is_slice_type()) return true; // An index into an array is addressable if the array is // addressable. return this->array_->is_addressable(); } void Array_index_expression::do_address_taken(bool escapes) { // In &x[0], if x is a slice, then x's address is not taken. if (!this->array_->type()->is_slice_type()) this->array_->address_taken(escapes); } // Get the backend representation for an array index. Bexpression* Array_index_expression::do_get_backend(Translate_context* context) { Array_type* array_type = this->array_->type()->array_type(); if (array_type == NULL) { go_assert(this->array_->type()->is_error()); return context->backend()->error_expression(); } go_assert(!array_type->is_slice_type() || this->array_->is_multi_eval_safe()); Location loc = this->location(); Gogo* gogo = context->gogo(); Type* int_type = Type::lookup_integer_type("int"); Btype* int_btype = int_type->get_backend(gogo); // Convert the length and capacity to "int". FIXME: Do we need to // do this? Bexpression* length = NULL; if (this->end_ == NULL || this->end_->is_nil_expression()) { Expression* len = array_type->get_length(gogo, this->array_); length = len->get_backend(context); length = gogo->backend()->convert_expression(int_btype, length, loc); } Bexpression* capacity = NULL; if (this->end_ != NULL) { Expression* cap = array_type->get_capacity(gogo, this->array_); capacity = cap->get_backend(context); capacity = gogo->backend()->convert_expression(int_btype, capacity, loc); } Bexpression* cap_arg = capacity; if (this->cap_ != NULL) { cap_arg = this->cap_->get_backend(context); cap_arg = gogo->backend()->convert_expression(int_btype, cap_arg, loc); } if (length == NULL) length = cap_arg; if (this->start_->type()->integer_type() == NULL && !Type::are_convertible(int_type, this->start_->type(), NULL)) { go_assert(saw_errors()); return context->backend()->error_expression(); } Bexpression* start = this->start_->get_backend(context); start = gogo->backend()->convert_expression(int_btype, start, loc); Bfunction* bfn = context->function()->func_value()->get_decl(); if (this->end_ == NULL) { // Simple array indexing. Bexpression* ret; if (!array_type->is_slice_type()) { Bexpression* array = this->array_->get_backend(context); ret = gogo->backend()->array_index_expression(array, start, loc); } else { Expression* valptr = array_type->get_value_pointer(gogo, this->array_); Bexpression* ptr = valptr->get_backend(context); ptr = gogo->backend()->pointer_offset_expression(ptr, start, loc); Type* ele_type = this->array_->type()->array_type()->element_type(); Btype* ele_btype = ele_type->get_backend(gogo); ret = gogo->backend()->indirect_expression(ele_btype, ptr, false, loc); } return ret; } // Slice expression. Bexpression* end; if (this->end_->is_nil_expression()) end = length; else { end = this->end_->get_backend(context); end = gogo->backend()->convert_expression(int_btype, end, loc); } Bexpression* result_length = gogo->backend()->binary_expression(OPERATOR_MINUS, end, start, loc); Bexpression* result_capacity = gogo->backend()->binary_expression(OPERATOR_MINUS, cap_arg, start, loc); // If the new capacity is zero, don't change val. Otherwise we can // get a pointer to the next object in memory, keeping it live // unnecessarily. When the capacity is zero, the actual pointer // value doesn't matter. Bexpression* zero = Expression::make_integer_ul(0, int_type, loc)->get_backend(context); Bexpression* cond = gogo->backend()->binary_expression(OPERATOR_EQEQ, result_capacity, zero, loc); Bexpression* offset = gogo->backend()->conditional_expression(bfn, int_btype, cond, zero, start, loc); Expression* valptr = array_type->get_value_pointer(gogo, this->array_); Bexpression* val = valptr->get_backend(context); val = gogo->backend()->pointer_offset_expression(val, offset, loc); Btype* struct_btype = this->type()->get_backend(gogo); std::vector init; init.push_back(val); init.push_back(result_length); init.push_back(result_capacity); return gogo->backend()->constructor_expression(struct_btype, init, loc); } // Export an array index expression. void Array_index_expression::do_export(Export_function_body* efb) const { efb->write_c_string("("); this->array_->export_expression(efb); efb->write_c_string(")["); Type* old_context = efb->type_context(); efb->set_type_context(Type::lookup_integer_type("int")); this->start_->export_expression(efb); if (this->end_ == NULL) go_assert(this->cap_ == NULL); else { efb->write_c_string(":"); if (!this->end_->is_nil_expression()) this->end_->export_expression(efb); if (this->cap_ != NULL) { efb->write_c_string(":"); this->cap_->export_expression(efb); } } efb->set_type_context(old_context); efb->write_c_string("]"); } // Dump ast representation for an array index expression. void Array_index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { Index_expression::dump_index_expression(ast_dump_context, this->array_, this->start_, this->end_, this->cap_); } // Make an array index expression. END and CAP may be NULL. Expression* Expression::make_array_index(Expression* array, Expression* start, Expression* end, Expression* cap, Location location) { return new Array_index_expression(array, start, end, cap, location); } // Class String_index_expression. // String index traversal. int String_index_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->string_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (Expression::traverse(&this->start_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (this->end_ != NULL) { if (Expression::traverse(&this->end_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } return TRAVERSE_CONTINUE; } Expression* String_index_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { if (this->is_flattened_) return this; this->is_flattened_ = true; Location loc = this->location(); if (this->is_error_expression()) return Expression::make_error(loc); Expression* string = this->string_; Expression* start = this->start_; Expression* end = this->end_; if (string->is_error_expression() || string->type()->is_error_type() || start->is_error_expression() || start->type()->is_error_type() || (end != NULL && (end->is_error_expression() || end->type()->is_error_type()))) { go_assert(saw_errors()); return Expression::make_error(loc); } Temporary_statement* temp; if (!string->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, string, loc); inserter->insert(temp); this->string_ = Expression::make_temporary_reference(temp, loc); string = this->string_; } if (!start->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, start, loc); inserter->insert(temp); this->start_ = Expression::make_temporary_reference(temp, loc); start = this->start_; } if (end != NULL && !end->is_nil_expression() && !end->is_multi_eval_safe()) { temp = Statement::make_temporary(NULL, end, loc); inserter->insert(temp); this->end_ = Expression::make_temporary_reference(temp, loc); end = this->end_; } Expression* len = Expression::make_string_info(string->copy(), STRING_INFO_LENGTH, loc); temp = Statement::make_temporary(NULL, len, loc); inserter->insert(temp); len = Expression::make_temporary_reference(temp, loc); // The order of bounds checks here matches the order used by the gc // compiler, as tested by issue30116[u].go. if (end != NULL && !end->is_nil_expression()) { Expression::check_bounds(end, OPERATOR_LE, len, Runtime::PANIC_SLICE_ALEN, Runtime::PANIC_SLICE_ALEN_U, Runtime::PANIC_EXTEND_SLICE_ALEN, Runtime::PANIC_EXTEND_SLICE_ALEN_U, inserter, loc); Expression::check_bounds(start, OPERATOR_LE, end, Runtime::PANIC_SLICE_B, Runtime::PANIC_SLICE_B_U, Runtime::PANIC_EXTEND_SLICE_B, Runtime::PANIC_EXTEND_SLICE_B_U, inserter, loc); } else if (end != NULL) Expression::check_bounds(start, OPERATOR_LE, len, Runtime::PANIC_SLICE_B, Runtime::PANIC_SLICE_B_U, Runtime::PANIC_EXTEND_SLICE_B, Runtime::PANIC_EXTEND_SLICE_B_U, inserter, loc); else Expression::check_bounds(start, OPERATOR_LT, len, Runtime::PANIC_INDEX, Runtime::PANIC_INDEX_U, Runtime::PANIC_EXTEND_INDEX, Runtime::PANIC_EXTEND_INDEX_U, inserter, loc); return this; } // Return the type of a string index. Type* String_index_expression::do_type() { if (this->end_ == NULL) return Type::lookup_integer_type("byte"); else return this->string_->type(); } // Determine the type of a string index. void String_index_expression::do_determine_type(const Type_context*) { this->string_->determine_type_no_context(); Type_context index_context(Type::lookup_integer_type("int"), false); this->start_->determine_type(&index_context); if (this->end_ != NULL) this->end_->determine_type(&index_context); } // Check types of a string index. void String_index_expression::do_check_types(Gogo*) { Numeric_constant nc; unsigned long v; if (this->start_->type()->integer_type() == NULL && !this->start_->type()->is_error() && (!this->start_->type()->is_abstract() || !this->start_->numeric_constant_value(&nc) || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) this->report_error(_("index must be integer")); if (this->end_ != NULL && this->end_->type()->integer_type() == NULL && !this->end_->type()->is_error() && !this->end_->is_nil_expression() && !this->end_->is_error_expression() && (!this->end_->type()->is_abstract() || !this->end_->numeric_constant_value(&nc) || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) this->report_error(_("slice end must be integer")); std::string sval; bool sval_valid = this->string_->string_constant_value(&sval); Numeric_constant inc; mpz_t ival; bool ival_valid = false; if (this->start_->numeric_constant_value(&inc) && inc.to_int(&ival)) { ival_valid = true; if (mpz_sgn(ival) < 0 || (sval_valid && (this->end_ == NULL ? mpz_cmp_ui(ival, sval.length()) >= 0 : mpz_cmp_ui(ival, sval.length()) > 0))) { go_error_at(this->start_->location(), "string index out of bounds"); this->set_is_error(); } } if (this->end_ != NULL && !this->end_->is_nil_expression()) { Numeric_constant enc; mpz_t eval; if (this->end_->numeric_constant_value(&enc) && enc.to_int(&eval)) { if (mpz_sgn(eval) < 0 || (sval_valid && mpz_cmp_ui(eval, sval.length()) > 0)) { go_error_at(this->end_->location(), "string index out of bounds"); this->set_is_error(); } else if (ival_valid && mpz_cmp(ival, eval) > 0) this->report_error(_("inverted slice range")); mpz_clear(eval); } } if (ival_valid) mpz_clear(ival); } // Get the backend representation for a string index. Bexpression* String_index_expression::do_get_backend(Translate_context* context) { Location loc = this->location(); Gogo* gogo = context->gogo(); Type* int_type = Type::lookup_integer_type("int"); // It is possible that an error occurred earlier because the start index // cannot be represented as an integer type. In this case, we shouldn't // try casting the starting index into an integer since // Type_conversion_expression will fail to get the backend representation. // FIXME. if (this->start_->type()->integer_type() == NULL && !Type::are_convertible(int_type, this->start_->type(), NULL)) { go_assert(saw_errors()); return context->backend()->error_expression(); } go_assert(this->string_->is_multi_eval_safe()); go_assert(this->start_->is_multi_eval_safe()); Expression* start = Expression::make_cast(int_type, this->start_, loc); Bfunction* bfn = context->function()->func_value()->get_decl(); Expression* length = Expression::make_string_info(this->string_, STRING_INFO_LENGTH, loc); Expression* bytes = Expression::make_string_info(this->string_, STRING_INFO_DATA, loc); Bexpression* bstart = start->get_backend(context); Bexpression* ptr = bytes->get_backend(context); if (this->end_ == NULL) { ptr = gogo->backend()->pointer_offset_expression(ptr, bstart, loc); Btype* ubtype = Type::lookup_integer_type("uint8")->get_backend(gogo); return gogo->backend()->indirect_expression(ubtype, ptr, false, loc); } Expression* end = NULL; if (this->end_->is_nil_expression()) end = length; else { go_assert(this->end_->is_multi_eval_safe()); end = Expression::make_cast(int_type, this->end_, loc); } end = end->copy(); Bexpression* bend = end->get_backend(context); Bexpression* new_length = gogo->backend()->binary_expression(OPERATOR_MINUS, bend, bstart, loc); // If the new length is zero, don't change pointer. Otherwise we can // get a pointer to the next object in memory, keeping it live // unnecessarily. When the length is zero, the actual pointer // value doesn't matter. Btype* int_btype = int_type->get_backend(gogo); Bexpression* zero = Expression::make_integer_ul(0, int_type, loc)->get_backend(context); Bexpression* cond = gogo->backend()->binary_expression(OPERATOR_EQEQ, new_length, zero, loc); Bexpression* offset = gogo->backend()->conditional_expression(bfn, int_btype, cond, zero, bstart, loc); ptr = gogo->backend()->pointer_offset_expression(ptr, offset, loc); Btype* str_btype = this->type()->get_backend(gogo); std::vector init; init.push_back(ptr); init.push_back(new_length); return gogo->backend()->constructor_expression(str_btype, init, loc); } // Export a string index expression. void String_index_expression::do_export(Export_function_body* efb) const { efb->write_c_string("("); this->string_->export_expression(efb); efb->write_c_string(")["); Type* old_context = efb->type_context(); efb->set_type_context(Type::lookup_integer_type("int")); this->start_->export_expression(efb); if (this->end_ != NULL) { efb->write_c_string(":"); if (!this->end_->is_nil_expression()) this->end_->export_expression(efb); } efb->set_type_context(old_context); efb->write_c_string("]"); } // Dump ast representation for a string index expression. void String_index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { Index_expression::dump_index_expression(ast_dump_context, this->string_, this->start_, this->end_, NULL); } // Make a string index expression. END may be NULL. Expression* Expression::make_string_index(Expression* string, Expression* start, Expression* end, Location location) { return new String_index_expression(string, start, end, location); } // Class Map_index. // Get the type of the map. Map_type* Map_index_expression::get_map_type() const { Map_type* mt = this->map_->type()->map_type(); if (mt == NULL) go_assert(saw_errors()); return mt; } // Map index traversal. int Map_index_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->map_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return Expression::traverse(&this->index_, traverse); } // We need to pass in a pointer to the key, so flatten the index into a // temporary variable if it isn't already. The value pointer will be // dereferenced and checked for nil, so flatten into a temporary to avoid // recomputation. Expression* Map_index_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { Location loc = this->location(); Map_type* mt = this->get_map_type(); if (this->index()->is_error_expression() || this->index()->type()->is_error_type() || mt->is_error_type()) { go_assert(saw_errors()); return Expression::make_error(loc); } // Avoid copy for string([]byte) conversions used in map keys. // mapaccess doesn't keep the reference, so this is safe. Type_conversion_expression* ce = this->index_->conversion_expression(); if (ce != NULL && ce->type()->is_string_type() && ce->expr()->type()->is_slice_type()) ce->set_no_copy(true); if (!Type::are_identical(mt->key_type(), this->index_->type(), Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) { if (this->index_->type()->interface_type() != NULL && !this->index_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->index_, loc); inserter->insert(temp); this->index_ = Expression::make_temporary_reference(temp, loc); } this->index_ = Expression::convert_for_assignment(gogo, mt->key_type(), this->index_, loc); } if (!this->index_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->index_, loc); inserter->insert(temp); this->index_ = Expression::make_temporary_reference(temp, loc); } if (this->value_pointer_ == NULL) this->get_value_pointer(gogo); if (this->value_pointer_->is_error_expression() || this->value_pointer_->type()->is_error_type()) return Expression::make_error(loc); if (!this->value_pointer_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->value_pointer_, loc); inserter->insert(temp); this->value_pointer_ = Expression::make_temporary_reference(temp, loc); } return this; } // Return the type of a map index. Type* Map_index_expression::do_type() { Map_type* mt = this->get_map_type(); if (mt == NULL) return Type::make_error_type(); return mt->val_type(); } // Fix the type of a map index. void Map_index_expression::do_determine_type(const Type_context*) { this->map_->determine_type_no_context(); Map_type* mt = this->get_map_type(); Type* key_type = mt == NULL ? NULL : mt->key_type(); Type_context subcontext(key_type, false); this->index_->determine_type(&subcontext); } // Check types of a map index. void Map_index_expression::do_check_types(Gogo*) { std::string reason; Map_type* mt = this->get_map_type(); if (mt == NULL) return; if (!Type::are_assignable(mt->key_type(), this->index_->type(), &reason)) { if (reason.empty()) this->report_error(_("incompatible type for map index")); else { go_error_at(this->location(), "incompatible type for map index (%s)", reason.c_str()); this->set_is_error(); } } } // Add explicit type conversions. void Map_index_expression::do_add_conversions() { Map_type* mt = this->get_map_type(); if (mt == NULL) return; Type* lt = mt->key_type(); Type* rt = this->index_->type(); if (!Type::are_identical(lt, rt, 0, NULL) && lt->interface_type() != NULL) this->index_ = Expression::make_cast(lt, this->index_, this->location()); } // Get the backend representation for a map index. Bexpression* Map_index_expression::do_get_backend(Translate_context* context) { Map_type* type = this->get_map_type(); if (type == NULL) { go_assert(saw_errors()); return context->backend()->error_expression(); } go_assert(this->value_pointer_ != NULL && this->value_pointer_->is_multi_eval_safe()); Expression* val = Expression::make_dereference(this->value_pointer_, NIL_CHECK_NOT_NEEDED, this->location()); return val->get_backend(context); } // Get an expression for the map index. This returns an expression // that evaluates to a pointer to a value. If the key is not in the // map, the pointer will point to a zero value. Expression* Map_index_expression::get_value_pointer(Gogo* gogo) { if (this->value_pointer_ == NULL) { Map_type* type = this->get_map_type(); if (type == NULL) { go_assert(saw_errors()); return Expression::make_error(this->location()); } Location loc = this->location(); Expression* map_ref = this->map_; Expression* index_ptr = Expression::make_unary(OPERATOR_AND, this->index_, loc); Expression* type_expr = Expression::make_type_descriptor(type, loc); Expression* zero = type->fat_zero_value(gogo); Expression* map_index; if (zero == NULL) { Runtime::Function code; Expression* key; switch (type->algorithm(gogo)) { case Map_type::MAP_ALG_FAST32: case Map_type::MAP_ALG_FAST32PTR: { Type* uint32_type = Type::lookup_integer_type("uint32"); Type* uint32_ptr_type = Type::make_pointer_type(uint32_type); key = Expression::make_unsafe_cast(uint32_ptr_type, index_ptr, loc); key = Expression::make_dereference(key, NIL_CHECK_NOT_NEEDED, loc); code = Runtime::MAPACCESS1_FAST32; break; } case Map_type::MAP_ALG_FAST64: case Map_type::MAP_ALG_FAST64PTR: { Type* uint64_type = Type::lookup_integer_type("uint64"); Type* uint64_ptr_type = Type::make_pointer_type(uint64_type); key = Expression::make_unsafe_cast(uint64_ptr_type, index_ptr, loc); key = Expression::make_dereference(key, NIL_CHECK_NOT_NEEDED, loc); code = Runtime::MAPACCESS1_FAST64; break; } case Map_type::MAP_ALG_FASTSTR: key = this->index_; code = Runtime::MAPACCESS1_FASTSTR; break; default: key = index_ptr; code = Runtime::MAPACCESS1; break; } map_index = Runtime::make_call(code, loc, 3, type_expr, map_ref, key); } else map_index = Runtime::make_call(Runtime::MAPACCESS1_FAT, loc, 4, type_expr, map_ref, index_ptr, zero); Type* val_type = type->val_type(); this->value_pointer_ = Expression::make_unsafe_cast(Type::make_pointer_type(val_type), map_index, this->location()); } return this->value_pointer_; } // Export a map index expression. void Map_index_expression::do_export(Export_function_body* efb) const { efb->write_c_string("("); this->map_->export_expression(efb); efb->write_c_string(")["); Type* old_context = efb->type_context(); efb->set_type_context(this->get_map_type()->key_type()); this->index_->export_expression(efb); efb->set_type_context(old_context); efb->write_c_string("]"); } // Dump ast representation for a map index expression void Map_index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { Index_expression::dump_index_expression(ast_dump_context, this->map_, this->index_, NULL, NULL); } // Make a map index expression. Map_index_expression* Expression::make_map_index(Expression* map, Expression* index, Location location) { return new Map_index_expression(map, index, location); } // Class Field_reference_expression. // Lower a field reference expression. There is nothing to lower, but // this is where we generate the tracking information for fields with // the magic go:"track" tag. Expression* Field_reference_expression::do_lower(Gogo* gogo, Named_object* function, Statement_inserter* inserter, int) { Struct_type* struct_type = this->expr_->type()->struct_type(); if (struct_type == NULL) { // Error will be reported elsewhere. return this; } const Struct_field* field = struct_type->field(this->field_index_); if (field == NULL) return this; if (!field->has_tag()) return this; if (field->tag().find("go:\"track\"") == std::string::npos) return this; // References from functions generated by the compiler don't count. if (function != NULL && function->func_value()->is_type_specific_function()) return this; // We have found a reference to a tracked field. Build a call to // the runtime function __go_fieldtrack with a string that describes // the field. FIXME: We should only call this once per referenced // field per function, not once for each reference to the field. if (this->called_fieldtrack_) return this; this->called_fieldtrack_ = true; Location loc = this->location(); std::string s = "fieldtrack \""; Named_type* nt = this->expr_->type()->unalias()->named_type(); if (nt == NULL || nt->named_object()->package() == NULL) s.append(gogo->pkgpath()); else s.append(nt->named_object()->package()->pkgpath()); s.push_back('.'); if (nt != NULL) s.append(Gogo::unpack_hidden_name(nt->name())); s.push_back('.'); s.append(Gogo::unpack_hidden_name(field->field_name())); s.push_back('"'); // We can't use a string here, because internally a string holds a // pointer to the actual bytes; when the linker garbage collects the // string, it won't garbage collect the bytes. So we use a // [...]byte. Expression* length_expr = Expression::make_integer_ul(s.length(), NULL, loc); Type* byte_type = Type::lookup_integer_type("byte"); Array_type* array_type = Type::make_array_type(byte_type, length_expr); array_type->set_is_array_incomparable(); Expression_list* bytes = new Expression_list(); for (std::string::const_iterator p = s.begin(); p != s.end(); p++) { unsigned char c = static_cast(*p); bytes->push_back(Expression::make_integer_ul(c, NULL, loc)); } Expression* e = Expression::make_composite_literal(array_type, 0, false, bytes, false, loc); Variable* var = new Variable(array_type, e, true, false, false, loc); static int count; char buf[50]; snprintf(buf, sizeof buf, "fieldtrack.%d", count); ++count; Named_object* no = gogo->add_variable(buf, var); e = Expression::make_var_reference(no, loc); e = Expression::make_unary(OPERATOR_AND, e, loc); Expression* call = Runtime::make_call(Runtime::FIELDTRACK, loc, 1, e); gogo->lower_expression(function, inserter, &call); inserter->insert(Statement::make_statement(call, false)); // Put this function, and the global variable we just created, into // unique sections. This will permit the linker to garbage collect // them if they are not referenced. The effect is that the only // strings, indicating field references, that will wind up in the // executable will be those for functions that are actually needed. if (function != NULL) function->func_value()->set_in_unique_section(); var->set_in_unique_section(); return this; } // Return the type of a field reference. Type* Field_reference_expression::do_type() { Type* type = this->expr_->type(); if (type->is_error()) return type; Struct_type* struct_type = type->struct_type(); go_assert(struct_type != NULL); return struct_type->field(this->field_index_)->type(); } // Check the types for a field reference. void Field_reference_expression::do_check_types(Gogo*) { Type* type = this->expr_->type(); if (type->is_error()) return; Struct_type* struct_type = type->struct_type(); go_assert(struct_type != NULL); go_assert(struct_type->field(this->field_index_) != NULL); } // Get the backend representation for a field reference. Bexpression* Field_reference_expression::do_get_backend(Translate_context* context) { Bexpression* bstruct = this->expr_->get_backend(context); return context->gogo()->backend()->struct_field_expression(bstruct, this->field_index_, this->location()); } // Dump ast representation for a field reference expression. void Field_reference_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { this->expr_->dump_expression(ast_dump_context); ast_dump_context->ostream() << "." << this->field_index_; } // Make a reference to a qualified identifier in an expression. Field_reference_expression* Expression::make_field_reference(Expression* expr, unsigned int field_index, Location location) { return new Field_reference_expression(expr, field_index, location); } // Class Interface_field_reference_expression. // Return an expression for the pointer to the function to call. Expression* Interface_field_reference_expression::get_function() { Expression* ref = this->expr_; Location loc = this->location(); if (ref->type()->points_to() != NULL) ref = Expression::make_dereference(ref, NIL_CHECK_DEFAULT, loc); Expression* mtable = Expression::make_interface_info(ref, INTERFACE_INFO_METHODS, loc); Struct_type* mtable_type = mtable->type()->points_to()->struct_type(); std::string name = Gogo::unpack_hidden_name(this->name_); unsigned int index; const Struct_field* field = mtable_type->find_local_field(name, &index); go_assert(field != NULL); mtable = Expression::make_dereference(mtable, NIL_CHECK_NOT_NEEDED, loc); return Expression::make_field_reference(mtable, index, loc); } // Return an expression for the first argument to pass to the interface // function. Expression* Interface_field_reference_expression::get_underlying_object() { Expression* expr = this->expr_; if (expr->type()->points_to() != NULL) expr = Expression::make_dereference(expr, NIL_CHECK_DEFAULT, this->location()); return Expression::make_interface_info(expr, INTERFACE_INFO_OBJECT, this->location()); } // Traversal. int Interface_field_reference_expression::do_traverse(Traverse* traverse) { return Expression::traverse(&this->expr_, traverse); } // Lower the expression. If this expression is not called, we need to // evaluate the expression twice when converting to the backend // interface. So introduce a temporary variable if necessary. Expression* Interface_field_reference_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { if (this->expr_->is_error_expression() || this->expr_->type()->is_error_type()) { go_assert(saw_errors()); return Expression::make_error(this->location()); } if (!this->expr_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->expr_, this->location()); inserter->insert(temp); this->expr_ = Expression::make_temporary_reference(temp, this->location()); } return this; } // Return the type of an interface field reference. Type* Interface_field_reference_expression::do_type() { Type* expr_type = this->expr_->type(); Type* points_to = expr_type->points_to(); if (points_to != NULL) expr_type = points_to; Interface_type* interface_type = expr_type->interface_type(); if (interface_type == NULL) return Type::make_error_type(); const Typed_identifier* method = interface_type->find_method(this->name_); if (method == NULL) return Type::make_error_type(); return method->type(); } // Determine types. void Interface_field_reference_expression::do_determine_type(const Type_context*) { this->expr_->determine_type_no_context(); } // Check the types for an interface field reference. void Interface_field_reference_expression::do_check_types(Gogo*) { Type* type = this->expr_->type(); Type* points_to = type->points_to(); if (points_to != NULL) type = points_to; Interface_type* interface_type = type->interface_type(); if (interface_type == NULL) { if (!type->is_error_type()) this->report_error(_("expected interface or pointer to interface")); } else { const Typed_identifier* method = interface_type->find_method(this->name_); if (method == NULL) { go_error_at(this->location(), "method %qs not in interface", Gogo::message_name(this->name_).c_str()); this->set_is_error(); } } } // If an interface field reference is not simply called, then it is // represented as a closure. The closure will hold a single variable, // the value of the interface on which the method should be called. // The function will be a simple thunk that pulls the value from the // closure and calls the method with the remaining arguments. // Because method values are not common, we don't build all thunks for // all possible interface methods, but instead only build them as we // need them. In particular, we even build them on demand for // interface methods defined in other packages. Interface_field_reference_expression::Interface_method_thunks Interface_field_reference_expression::interface_method_thunks; // Find or create the thunk to call method NAME on TYPE. Named_object* Interface_field_reference_expression::create_thunk(Gogo* gogo, Interface_type* type, const std::string& name) { std::pair val(type, NULL); std::pair ins = Interface_field_reference_expression::interface_method_thunks.insert(val); if (ins.second) { // This is the first time we have seen this interface. ins.first->second = new Method_thunks(); } for (Method_thunks::const_iterator p = ins.first->second->begin(); p != ins.first->second->end(); p++) if (p->first == name) return p->second; Location loc = type->location(); const Typed_identifier* method_id = type->find_method(name); if (method_id == NULL) return Named_object::make_erroneous_name(gogo->thunk_name()); Function_type* orig_fntype = method_id->type()->function_type(); if (orig_fntype == NULL) return Named_object::make_erroneous_name(gogo->thunk_name()); Struct_field_list* sfl = new Struct_field_list(); // The type here is wrong--it should be the C function type. But it // doesn't really matter. Type* vt = Type::make_pointer_type(Type::make_void_type()); sfl->push_back(Struct_field(Typed_identifier("fn", vt, loc))); sfl->push_back(Struct_field(Typed_identifier("val", type, loc))); Struct_type* st = Type::make_struct_type(sfl, loc); st->set_is_struct_incomparable(); Type* closure_type = Type::make_pointer_type(st); Function_type* new_fntype = orig_fntype->copy_with_names(); std::string thunk_name = gogo->thunk_name(); Named_object* new_no = gogo->start_function(thunk_name, new_fntype, false, loc); Variable* cvar = new Variable(closure_type, NULL, false, false, false, loc); cvar->set_is_used(); cvar->set_is_closure(); Named_object* cp = Named_object::make_variable("$closure" + thunk_name, NULL, cvar); new_no->func_value()->set_closure_var(cp); gogo->start_block(loc); // Field 0 of the closure is the function code pointer, field 1 is // the value on which to invoke the method. Expression* arg = Expression::make_var_reference(cp, loc); arg = Expression::make_dereference(arg, NIL_CHECK_NOT_NEEDED, loc); arg = Expression::make_field_reference(arg, 1, loc); Expression *ifre = Expression::make_interface_field_reference(arg, name, loc); const Typed_identifier_list* orig_params = orig_fntype->parameters(); Expression_list* args; if (orig_params == NULL || orig_params->empty()) args = NULL; else { const Typed_identifier_list* new_params = new_fntype->parameters(); args = new Expression_list(); for (Typed_identifier_list::const_iterator p = new_params->begin(); p != new_params->end(); ++p) { Named_object* p_no = gogo->lookup(p->name(), NULL); go_assert(p_no != NULL && p_no->is_variable() && p_no->var_value()->is_parameter()); args->push_back(Expression::make_var_reference(p_no, loc)); } } Call_expression* call = Expression::make_call(ifre, args, orig_fntype->is_varargs(), loc); call->set_varargs_are_lowered(); Statement* s = Statement::make_return_from_call(call, loc); gogo->add_statement(s); Block* b = gogo->finish_block(loc); gogo->add_block(b, loc); // This is called after lowering but before determine_types. gogo->lower_block(new_no, b); gogo->finish_function(loc); ins.first->second->push_back(std::make_pair(name, new_no)); return new_no; } // Lookup a thunk to call method NAME on TYPE. Named_object* Interface_field_reference_expression::lookup_thunk(Interface_type* type, const std::string& name) { Interface_method_thunks::const_iterator p = Interface_field_reference_expression::interface_method_thunks.find(type); if (p == Interface_field_reference_expression::interface_method_thunks.end()) return NULL; for (Method_thunks::const_iterator pm = p->second->begin(); pm != p->second->end(); ++pm) if (pm->first == name) return pm->second; return NULL; } // Get the backend representation for a method value. Bexpression* Interface_field_reference_expression::do_get_backend(Translate_context* context) { Interface_type* type = this->expr_->type()->interface_type(); if (type == NULL) { go_assert(saw_errors()); return context->backend()->error_expression(); } Named_object* thunk = Interface_field_reference_expression::lookup_thunk(type, this->name_); // The thunk should have been created during the // create_function_descriptors pass. if (thunk == NULL || thunk->is_erroneous()) { go_assert(saw_errors()); return context->backend()->error_expression(); } // FIXME: We should lower this earlier, but we can't it lower it in // the lowering pass because at that point we don't know whether we // need to create the thunk or not. If the expression is called, we // don't need the thunk. Location loc = this->location(); Struct_field_list* fields = new Struct_field_list(); fields->push_back(Struct_field(Typed_identifier("fn", thunk->func_value()->type(), loc))); fields->push_back(Struct_field(Typed_identifier("val", this->expr_->type(), loc))); Struct_type* st = Type::make_struct_type(fields, loc); st->set_is_struct_incomparable(); Expression_list* vals = new Expression_list(); vals->push_back(Expression::make_func_code_reference(thunk, loc)); vals->push_back(this->expr_); Expression* expr = Expression::make_struct_composite_literal(st, vals, loc); Bexpression* bclosure = Expression::make_heap_expression(expr, loc)->get_backend(context); Gogo* gogo = context->gogo(); Btype* btype = this->type()->get_backend(gogo); bclosure = gogo->backend()->convert_expression(btype, bclosure, loc); Expression* nil_check = Expression::make_binary(OPERATOR_EQEQ, this->expr_, Expression::make_nil(loc), loc); Bexpression* bnil_check = nil_check->get_backend(context); Expression* crash = Runtime::make_call(Runtime::PANIC_MEM, loc, 0); Bexpression* bcrash = crash->get_backend(context); Bfunction* bfn = context->function()->func_value()->get_decl(); Bexpression* bcond = gogo->backend()->conditional_expression(bfn, NULL, bnil_check, bcrash, NULL, loc); Bfunction* bfunction = context->function()->func_value()->get_decl(); Bstatement* cond_statement = gogo->backend()->expression_statement(bfunction, bcond); return gogo->backend()->compound_expression(cond_statement, bclosure, loc); } // Dump ast representation for an interface field reference. void Interface_field_reference_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { this->expr_->dump_expression(ast_dump_context); ast_dump_context->ostream() << "." << this->name_; } // Make a reference to a field in an interface. Expression* Expression::make_interface_field_reference(Expression* expr, const std::string& field, Location location) { return new Interface_field_reference_expression(expr, field, location); } // A general selector. This is a Parser_expression for LEFT.NAME. It // is lowered after we know the type of the left hand side. class Selector_expression : public Parser_expression { public: Selector_expression(Expression* left, const std::string& name, Location location) : Parser_expression(EXPRESSION_SELECTOR, location), left_(left), name_(name) { } protected: int do_traverse(Traverse* traverse) { return Expression::traverse(&this->left_, traverse); } Expression* do_lower(Gogo*, Named_object*, Statement_inserter*, int); Expression* do_copy() { return new Selector_expression(this->left_->copy(), this->name_, this->location()); } void do_dump_expression(Ast_dump_context* ast_dump_context) const; private: Expression* lower_method_expression(Gogo*); // The expression on the left hand side. Expression* left_; // The name on the right hand side. std::string name_; }; // Lower a selector expression once we know the real type of the left // hand side. Expression* Selector_expression::do_lower(Gogo* gogo, Named_object*, Statement_inserter*, int) { Expression* left = this->left_; if (left->is_type_expression()) return this->lower_method_expression(gogo); return Type::bind_field_or_method(gogo, left->type(), left, this->name_, this->location()); } // Lower a method expression T.M or (*T).M. We turn this into a // function literal. Expression* Selector_expression::lower_method_expression(Gogo* gogo) { Location location = this->location(); Type* left_type = this->left_->type(); Type* type = left_type; const std::string& name(this->name_); bool is_pointer; if (type->points_to() == NULL) is_pointer = false; else { is_pointer = true; type = type->points_to(); } Named_type* nt = type->named_type(); Struct_type* st = type->struct_type(); bool is_ambiguous; Method* method = NULL; if (nt != NULL) method = nt->method_function(name, &is_ambiguous); else if (st != NULL) method = st->method_function(name, &is_ambiguous); const Typed_identifier* imethod = NULL; if (method == NULL && !is_pointer) { Interface_type* it = type->interface_type(); if (it != NULL) imethod = it->find_method(name); } if ((method == NULL && imethod == NULL) || (left_type->named_type() != NULL && left_type->points_to() != NULL)) { if (nt != NULL) { if (!is_ambiguous) go_error_at(location, "type %<%s%s%> has no method %<%s%>", is_pointer ? "*" : "", nt->message_name().c_str(), Gogo::message_name(name).c_str()); else go_error_at(location, "method %<%s%s%> is ambiguous in type %<%s%>", Gogo::message_name(name).c_str(), is_pointer ? "*" : "", nt->message_name().c_str()); } else { if (!is_ambiguous) go_error_at(location, "type has no method %<%s%>", Gogo::message_name(name).c_str()); else go_error_at(location, "method %<%s%> is ambiguous", Gogo::message_name(name).c_str()); } return Expression::make_error(location); } if (method != NULL && !is_pointer && !method->is_value_method()) { go_error_at(location, "method requires pointer (use %<(*%s).%s%>)", nt->message_name().c_str(), Gogo::message_name(name).c_str()); return Expression::make_error(location); } // Build a new function type in which the receiver becomes the first // argument. Function_type* method_type; if (method != NULL) { method_type = method->type(); go_assert(method_type->is_method()); } else { method_type = imethod->type()->function_type(); go_assert(method_type != NULL && !method_type->is_method()); } const char* const receiver_name = "$this"; Typed_identifier_list* parameters = new Typed_identifier_list(); parameters->push_back(Typed_identifier(receiver_name, this->left_->type(), location)); const Typed_identifier_list* method_parameters = method_type->parameters(); if (method_parameters != NULL) { int i = 0; for (Typed_identifier_list::const_iterator p = method_parameters->begin(); p != method_parameters->end(); ++p, ++i) { if (!p->name().empty() && !Gogo::is_sink_name(p->name())) parameters->push_back(*p); else { char buf[20]; snprintf(buf, sizeof buf, "$param%d", i); parameters->push_back(Typed_identifier(buf, p->type(), p->location())); } } } const Typed_identifier_list* method_results = method_type->results(); Typed_identifier_list* results; if (method_results == NULL) results = NULL; else { results = new Typed_identifier_list(); for (Typed_identifier_list::const_iterator p = method_results->begin(); p != method_results->end(); ++p) results->push_back(*p); } Function_type* fntype = Type::make_function_type(NULL, parameters, results, location); if (method_type->is_varargs()) fntype->set_is_varargs(); // We generate methods which always takes a pointer to the receiver // as their first argument. If this is for a pointer type, we can // simply reuse the existing function. We use an internal hack to // get the right type. // FIXME: This optimization is disabled because it doesn't yet work // with function descriptors when the method expression is not // directly called. if (method != NULL && is_pointer && false) { Named_object* mno = (method->needs_stub_method() ? method->stub_object() : method->named_object()); Expression* f = Expression::make_func_reference(mno, NULL, location); f = Expression::make_cast(fntype, f, location); Type_conversion_expression* tce = static_cast(f); tce->set_may_convert_function_types(); return f; } Named_object* no = gogo->start_function(gogo->thunk_name(), fntype, false, location); Named_object* vno = gogo->lookup(receiver_name, NULL); go_assert(vno != NULL); Expression* ve = Expression::make_var_reference(vno, location); Expression* bm; if (method != NULL) bm = Type::bind_field_or_method(gogo, type, ve, name, location); else bm = Expression::make_interface_field_reference(ve, name, location); // Even though we found the method above, if it has an error type we // may see an error here. if (bm->is_error_expression()) { gogo->finish_function(location); return bm; } Expression_list* args; if (parameters->size() <= 1) args = NULL; else { args = new Expression_list(); Typed_identifier_list::const_iterator p = parameters->begin(); ++p; for (; p != parameters->end(); ++p) { vno = gogo->lookup(p->name(), NULL); go_assert(vno != NULL); args->push_back(Expression::make_var_reference(vno, location)); } } gogo->start_block(location); Call_expression* call = Expression::make_call(bm, args, method_type->is_varargs(), location); Statement* s = Statement::make_return_from_call(call, location); gogo->add_statement(s); Block* b = gogo->finish_block(location); gogo->add_block(b, location); // Lower the call in case there are multiple results. gogo->lower_block(no, b); gogo->flatten_block(no, b); gogo->finish_function(location); return Expression::make_func_reference(no, NULL, location); } // Dump the ast for a selector expression. void Selector_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_expression(this->left_); ast_dump_context->ostream() << "."; ast_dump_context->ostream() << this->name_; } // Make a selector expression. Expression* Expression::make_selector(Expression* left, const std::string& name, Location location) { return new Selector_expression(left, name, location); } // Class Allocation_expression. int Allocation_expression::do_traverse(Traverse* traverse) { return Type::traverse(this->type_, traverse); } Type* Allocation_expression::do_type() { return Type::make_pointer_type(this->type_); } void Allocation_expression::do_check_types(Gogo*) { if (!this->type_->in_heap()) go_error_at(this->location(), "cannot heap allocate go:notinheap type"); } // Make a copy of an allocation expression. Expression* Allocation_expression::do_copy() { Allocation_expression* alloc = new Allocation_expression(this->type_->copy_expressions(), this->location()); if (this->allocate_on_stack_) alloc->set_allocate_on_stack(); if (this->no_zero_) alloc->set_no_zero(); return alloc; } // Return the backend representation for an allocation expression. Bexpression* Allocation_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Location loc = this->location(); Btype* btype = this->type_->get_backend(gogo); if (this->allocate_on_stack_) { int64_t size; bool ok = this->type_->backend_type_size(gogo, &size); if (!ok) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } Bstatement* decl; Named_object* fn = context->function(); go_assert(fn != NULL); Bfunction* fndecl = fn->func_value()->get_or_make_decl(gogo, fn); Bexpression* init = (this->no_zero_ ? NULL : gogo->backend()->zero_expression(btype)); Bvariable* temp = gogo->backend()->temporary_variable(fndecl, context->bblock(), btype, init, Backend::variable_address_is_taken, loc, &decl); Bexpression* ret = gogo->backend()->var_expression(temp, loc); ret = gogo->backend()->address_expression(ret, loc); ret = gogo->backend()->compound_expression(decl, ret, loc); return ret; } Bexpression* space = gogo->allocate_memory(this->type_, loc)->get_backend(context); Btype* pbtype = gogo->backend()->pointer_type(btype); return gogo->backend()->convert_expression(pbtype, space, loc); } // Dump ast representation for an allocation expression. void Allocation_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "new("; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << ")"; } // Make an allocation expression. Expression* Expression::make_allocation(Type* type, Location location) { return new Allocation_expression(type, location); } // Class Ordered_value_list. int Ordered_value_list::traverse_vals(Traverse* traverse) { if (this->vals_ != NULL) { if (this->traverse_order_ == NULL) { if (this->vals_->traverse(traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } else { for (std::vector::const_iterator p = this->traverse_order_->begin(); p != this->traverse_order_->end(); ++p) { if (Expression::traverse(&this->vals_->at(*p), traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } } } return TRAVERSE_CONTINUE; } // Class Struct_construction_expression. // Traversal. int Struct_construction_expression::do_traverse(Traverse* traverse) { if (this->traverse_vals(traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Return whether this is a constant initializer. bool Struct_construction_expression::is_constant_struct() const { if (this->vals() == NULL) return true; for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { if (*pv != NULL && !(*pv)->is_constant() && (!(*pv)->is_composite_literal() || (*pv)->is_nonconstant_composite_literal())) return false; } const Struct_field_list* fields = this->type_->struct_type()->fields(); for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf) { // There are no constant constructors for interfaces. if (pf->type()->interface_type() != NULL) return false; } return true; } // Return whether this is a zero value. bool Struct_construction_expression::do_is_zero_value() const { if (this->vals() == NULL) return true; for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) if (*pv != NULL && !(*pv)->is_zero_value()) return false; const Struct_field_list* fields = this->type_->struct_type()->fields(); for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf) { // Interface conversion may cause a zero value being converted // to a non-zero value, like interface{}(0). Be conservative. if (pf->type()->interface_type() != NULL) return false; } return true; } // Return whether this struct can be used as a constant initializer. bool Struct_construction_expression::do_is_static_initializer() const { if (this->vals() == NULL) return true; for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { if (*pv != NULL && !(*pv)->is_static_initializer()) return false; } const Struct_field_list* fields = this->type_->struct_type()->fields(); for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf) { // There are no constant constructors for interfaces. if (pf->type()->interface_type() != NULL) return false; } return true; } // Final type determination. void Struct_construction_expression::do_determine_type(const Type_context*) { if (this->vals() == NULL) return; const Struct_field_list* fields = this->type_->struct_type()->fields(); Expression_list::const_iterator pv = this->vals()->begin(); for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf, ++pv) { if (pv == this->vals()->end()) return; if (*pv != NULL) { Type_context subcontext(pf->type(), false); (*pv)->determine_type(&subcontext); } } // Extra values are an error we will report elsewhere; we still want // to determine the type to avoid knockon errors. for (; pv != this->vals()->end(); ++pv) (*pv)->determine_type_no_context(); } // Check types. void Struct_construction_expression::do_check_types(Gogo*) { if (this->vals() == NULL) return; Struct_type* st = this->type_->struct_type(); if (this->vals()->size() > st->field_count()) { this->report_error(_("too many expressions for struct")); return; } const Struct_field_list* fields = st->fields(); Expression_list::const_iterator pv = this->vals()->begin(); int i = 0; for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf, ++pv, ++i) { if (pv == this->vals()->end()) { this->report_error(_("too few expressions for struct")); break; } if (*pv == NULL) continue; std::string reason; if (!Type::are_assignable(pf->type(), (*pv)->type(), &reason)) { if (reason.empty()) go_error_at((*pv)->location(), "incompatible type for field %d in struct construction", i + 1); else go_error_at((*pv)->location(), ("incompatible type for field %d in " "struct construction (%s)"), i + 1, reason.c_str()); this->set_is_error(); } } go_assert(pv == this->vals()->end()); } // Copy. Expression* Struct_construction_expression::do_copy() { Struct_construction_expression* ret = new Struct_construction_expression(this->type_->copy_expressions(), (this->vals() == NULL ? NULL : this->vals()->copy()), this->location()); if (this->traverse_order() != NULL) ret->set_traverse_order(this->traverse_order()); return ret; } // Make implicit type conversions explicit. void Struct_construction_expression::do_add_conversions() { if (this->vals() == NULL) return; Location loc = this->location(); const Struct_field_list* fields = this->type_->struct_type()->fields(); Expression_list::iterator pv = this->vals()->begin(); for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf, ++pv) { if (pv == this->vals()->end()) break; if (*pv != NULL) { Type* ft = pf->type(); if (!Type::are_identical(ft, (*pv)->type(), 0, NULL) && ft->interface_type() != NULL) *pv = Expression::make_cast(ft, *pv, loc); } } } // Return the backend representation for constructing a struct. Bexpression* Struct_construction_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Btype* btype = this->type_->get_backend(gogo); if (this->vals() == NULL) return gogo->backend()->zero_expression(btype); const Struct_field_list* fields = this->type_->struct_type()->fields(); Expression_list::const_iterator pv = this->vals()->begin(); std::vector init; for (Struct_field_list::const_iterator pf = fields->begin(); pf != fields->end(); ++pf) { Btype* fbtype = pf->type()->get_backend(gogo); if (pv == this->vals()->end()) init.push_back(gogo->backend()->zero_expression(fbtype)); else if (*pv == NULL) { init.push_back(gogo->backend()->zero_expression(fbtype)); ++pv; } else { Expression* val = Expression::convert_for_assignment(gogo, pf->type(), *pv, this->location()); init.push_back(val->get_backend(context)); ++pv; } } if (this->type_->struct_type()->has_padding()) { // Feed an extra value if there is a padding field. Btype *fbtype = Type::lookup_integer_type("uint8")->get_backend(gogo); init.push_back(gogo->backend()->zero_expression(fbtype)); } return gogo->backend()->constructor_expression(btype, init, this->location()); } // Export a struct construction. void Struct_construction_expression::do_export(Export_function_body* efb) const { efb->write_c_string("$convert("); efb->write_type(this->type_); for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { efb->write_c_string(", "); if (*pv != NULL) (*pv)->export_expression(efb); } efb->write_c_string(")"); } // Dump ast representation of a struct construction expression. void Struct_construction_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << "{"; ast_dump_context->dump_expression_list(this->vals()); ast_dump_context->ostream() << "}"; } // Make a struct composite literal. This used by the thunk code. Expression* Expression::make_struct_composite_literal(Type* type, Expression_list* vals, Location location) { go_assert(type->struct_type() != NULL); return new Struct_construction_expression(type, vals, location); } // Class Array_construction_expression. // Traversal. int Array_construction_expression::do_traverse(Traverse* traverse) { if (this->traverse_vals(traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Return whether this is a constant initializer. bool Array_construction_expression::is_constant_array() const { if (this->vals() == NULL) return true; // There are no constant constructors for interfaces. if (this->type_->array_type()->element_type()->interface_type() != NULL) return false; for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { if (*pv != NULL && !(*pv)->is_constant() && (!(*pv)->is_composite_literal() || (*pv)->is_nonconstant_composite_literal())) return false; } return true; } // Return whether this is a zero value. bool Array_construction_expression::do_is_zero_value() const { if (this->vals() == NULL) return true; // Interface conversion may cause a zero value being converted // to a non-zero value, like interface{}(0). Be conservative. if (this->type_->array_type()->element_type()->interface_type() != NULL) return false; for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) if (*pv != NULL && !(*pv)->is_zero_value()) return false; return true; } // Return whether this can be used a constant initializer. bool Array_construction_expression::do_is_static_initializer() const { if (this->vals() == NULL) return true; // There are no constant constructors for interfaces. if (this->type_->array_type()->element_type()->interface_type() != NULL) return false; for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { if (*pv != NULL && !(*pv)->is_static_initializer()) return false; } return true; } // Final type determination. void Array_construction_expression::do_determine_type(const Type_context*) { if (this->is_error_expression()) { go_assert(saw_errors()); return; } if (this->vals() == NULL) return; Array_type* at = this->type_->array_type(); if (at == NULL || at->is_error() || at->element_type()->is_error()) { go_assert(saw_errors()); this->set_is_error(); return; } Type_context subcontext(at->element_type(), false); for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { if (*pv != NULL) (*pv)->determine_type(&subcontext); } } // Check types. void Array_construction_expression::do_check_types(Gogo*) { if (this->is_error_expression()) { go_assert(saw_errors()); return; } if (this->vals() == NULL) return; Array_type* at = this->type_->array_type(); if (at == NULL || at->is_error() || at->element_type()->is_error()) { go_assert(saw_errors()); this->set_is_error(); return; } int i = 0; Type* element_type = at->element_type(); for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv, ++i) { if (*pv != NULL && !Type::are_assignable(element_type, (*pv)->type(), NULL)) { go_error_at((*pv)->location(), "incompatible type for element %d in composite literal", i + 1); this->set_is_error(); } } } // Make implicit type conversions explicit. void Array_construction_expression::do_add_conversions() { if (this->is_error_expression()) { go_assert(saw_errors()); return; } if (this->vals() == NULL) return; Type* et = this->type_->array_type()->element_type(); if (et->interface_type() == NULL) return; Location loc = this->location(); for (Expression_list::iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) if (!Type::are_identical(et, (*pv)->type(), 0, NULL)) *pv = Expression::make_cast(et, *pv, loc); } // Get a constructor expression for the array values. Bexpression* Array_construction_expression::get_constructor(Translate_context* context, Btype* array_btype) { Type* element_type = this->type_->array_type()->element_type(); std::vector indexes; std::vector vals; Gogo* gogo = context->gogo(); if (this->vals() != NULL) { size_t i = 0; std::vector::const_iterator pi; if (this->indexes_ != NULL) pi = this->indexes_->begin(); for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv, ++i) { if (this->indexes_ != NULL) go_assert(pi != this->indexes_->end()); if (this->indexes_ == NULL) indexes.push_back(i); else indexes.push_back(*pi); if (*pv == NULL) { Btype* ebtype = element_type->get_backend(gogo); Bexpression *zv = gogo->backend()->zero_expression(ebtype); vals.push_back(zv); } else { Expression* val_expr = Expression::convert_for_assignment(gogo, element_type, *pv, this->location()); vals.push_back(val_expr->get_backend(context)); } if (this->indexes_ != NULL) ++pi; } if (this->indexes_ != NULL) go_assert(pi == this->indexes_->end()); } return gogo->backend()->array_constructor_expression(array_btype, indexes, vals, this->location()); } // Export an array construction. void Array_construction_expression::do_export(Export_function_body* efb) const { efb->write_c_string("$convert("); efb->write_type(this->type_); if (this->vals() != NULL) { std::vector::const_iterator pi; if (this->indexes_ != NULL) pi = this->indexes_->begin(); for (Expression_list::const_iterator pv = this->vals()->begin(); pv != this->vals()->end(); ++pv) { efb->write_c_string(", "); if (this->indexes_ != NULL) { char buf[100]; snprintf(buf, sizeof buf, "%lu", *pi); efb->write_c_string(buf); efb->write_c_string(":"); } if (*pv != NULL) (*pv)->export_expression(efb); if (this->indexes_ != NULL) ++pi; } } efb->write_c_string(")"); } // Dump ast representation of an array construction expression. void Array_construction_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { Expression* length = this->type_->array_type()->length(); ast_dump_context->ostream() << "[" ; if (length != NULL) { ast_dump_context->dump_expression(length); } ast_dump_context->ostream() << "]" ; ast_dump_context->dump_type(this->type_); this->dump_slice_storage_expression(ast_dump_context); ast_dump_context->ostream() << "{" ; if (this->indexes_ == NULL) ast_dump_context->dump_expression_list(this->vals()); else { Expression_list::const_iterator pv = this->vals()->begin(); for (std::vector::const_iterator pi = this->indexes_->begin(); pi != this->indexes_->end(); ++pi, ++pv) { if (pi != this->indexes_->begin()) ast_dump_context->ostream() << ", "; ast_dump_context->ostream() << *pi << ':'; ast_dump_context->dump_expression(*pv); } } ast_dump_context->ostream() << "}" ; } // Class Fixed_array_construction_expression. Fixed_array_construction_expression::Fixed_array_construction_expression( Type* type, const std::vector* indexes, Expression_list* vals, Location location) : Array_construction_expression(EXPRESSION_FIXED_ARRAY_CONSTRUCTION, type, indexes, vals, location) { go_assert(type->array_type() != NULL && !type->is_slice_type()); } // Copy. Expression* Fixed_array_construction_expression::do_copy() { Type* t = this->type()->copy_expressions(); return new Fixed_array_construction_expression(t, this->indexes(), (this->vals() == NULL ? NULL : this->vals()->copy()), this->location()); } // Return the backend representation for constructing a fixed array. Bexpression* Fixed_array_construction_expression::do_get_backend(Translate_context* context) { Type* type = this->type(); Btype* btype = type->get_backend(context->gogo()); return this->get_constructor(context, btype); } Expression* Expression::make_array_composite_literal(Type* type, Expression_list* vals, Location location) { go_assert(type->array_type() != NULL && !type->is_slice_type()); return new Fixed_array_construction_expression(type, NULL, vals, location); } // Class Slice_construction_expression. Slice_construction_expression::Slice_construction_expression( Type* type, const std::vector* indexes, Expression_list* vals, Location location) : Array_construction_expression(EXPRESSION_SLICE_CONSTRUCTION, type, indexes, vals, location), valtype_(NULL), array_val_(NULL), slice_storage_(NULL), storage_escapes_(true) { go_assert(type->is_slice_type()); unsigned long lenval; Expression* length; if (vals == NULL || vals->empty()) lenval = 0; else { if (this->indexes() == NULL) lenval = vals->size(); else lenval = indexes->back() + 1; } Type* int_type = Type::lookup_integer_type("int"); length = Expression::make_integer_ul(lenval, int_type, location); Type* element_type = type->array_type()->element_type(); Array_type* array_type = Type::make_array_type(element_type, length); array_type->set_is_array_incomparable(); this->valtype_ = array_type; } // Traversal. int Slice_construction_expression::do_traverse(Traverse* traverse) { if (this->Array_construction_expression::do_traverse(traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (Type::traverse(this->valtype_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (this->array_val_ != NULL && Expression::traverse(&this->array_val_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (this->slice_storage_ != NULL && Expression::traverse(&this->slice_storage_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Helper routine to create fixed array value underlying the slice literal. // May be called during flattening, or later during do_get_backend(). Expression* Slice_construction_expression::create_array_val() { Array_type* array_type = this->type()->array_type(); if (array_type == NULL) { go_assert(this->type()->is_error()); return NULL; } Location loc = this->location(); go_assert(this->valtype_ != NULL); Expression_list* vals = this->vals(); return new Fixed_array_construction_expression( this->valtype_, this->indexes(), vals, loc); } // If we're previous established that the slice storage does not // escape, then create a separate array temp val here for it. We // need to do this as part of flattening so as to be able to insert // the new temp statement. Expression* Slice_construction_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { if (this->type()->array_type() == NULL) { go_assert(saw_errors()); return Expression::make_error(this->location()); } // Create a stack-allocated storage temp if storage won't escape if (!this->storage_escapes_ && this->slice_storage_ == NULL && this->element_count() > 0) { Location loc = this->location(); this->array_val_ = this->create_array_val(); go_assert(this->array_val_ != NULL); Temporary_statement* temp = Statement::make_temporary(this->valtype_, this->array_val_, loc); inserter->insert(temp); this->slice_storage_ = Expression::make_temporary_reference(temp, loc); } return this; } // When dumping a slice construction expression that has an explicit // storeage temp, emit the temp here (if we don't do this the storage // temp appears unused in the AST dump). void Slice_construction_expression:: dump_slice_storage_expression(Ast_dump_context* ast_dump_context) const { if (this->slice_storage_ == NULL) return; ast_dump_context->ostream() << "storage=" ; ast_dump_context->dump_expression(this->slice_storage_); } // Copy. Expression* Slice_construction_expression::do_copy() { return new Slice_construction_expression(this->type()->copy_expressions(), this->indexes(), (this->vals() == NULL ? NULL : this->vals()->copy()), this->location()); } // Return the backend representation for constructing a slice. Bexpression* Slice_construction_expression::do_get_backend(Translate_context* context) { if (this->array_val_ == NULL) this->array_val_ = this->create_array_val(); if (this->array_val_ == NULL) { go_assert(this->type()->is_error()); return context->backend()->error_expression(); } Location loc = this->location(); bool is_static_initializer = this->array_val_->is_static_initializer(); // We have to copy the initial values into heap memory if we are in // a function or if the values are not constants. bool copy_to_heap = context->function() != NULL || !is_static_initializer; Expression* space; if (this->slice_storage_ != NULL) { go_assert(!this->storage_escapes_); space = Expression::make_unary(OPERATOR_AND, this->slice_storage_, loc); } else if (!copy_to_heap) { // The initializer will only run once. space = Expression::make_unary(OPERATOR_AND, this->array_val_, loc); space->unary_expression()->set_is_slice_init(); } else { go_assert(this->storage_escapes_ || this->element_count() == 0); space = Expression::make_heap_expression(this->array_val_, loc); } Array_type* at = this->valtype_->array_type(); Type* et = at->element_type(); space = Expression::make_unsafe_cast(Type::make_pointer_type(et), space, loc); // Build a constructor for the slice. Expression* len = at->length(); Expression* slice_val = Expression::make_slice_value(this->type(), space, len, len, loc); return slice_val->get_backend(context); } // Make a slice composite literal. This is used by the type // descriptor code. Slice_construction_expression* Expression::make_slice_composite_literal(Type* type, Expression_list* vals, Location location) { go_assert(type->is_slice_type()); return new Slice_construction_expression(type, NULL, vals, location); } // Class Map_construction_expression. // Traversal. int Map_construction_expression::do_traverse(Traverse* traverse) { if (this->vals_ != NULL && this->vals_->traverse(traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Flatten constructor initializer into a temporary variable since // we need to take its address for __go_construct_map. Expression* Map_construction_expression::do_flatten(Gogo* gogo, Named_object*, Statement_inserter* inserter) { if (!this->is_error_expression() && this->vals_ != NULL && !this->vals_->empty() && this->constructor_temp_ == NULL) { Map_type* mt = this->type_->map_type(); Type* key_type = mt->key_type(); Type* val_type = mt->val_type(); this->element_type_ = Type::make_builtin_struct_type(2, "__key", key_type, "__val", val_type); Expression_list* value_pairs = new Expression_list(); Location loc = this->location(); size_t i = 0; for (Expression_list::const_iterator pv = this->vals_->begin(); pv != this->vals_->end(); ++pv, ++i) { Expression_list* key_value_pair = new Expression_list(); Expression* key = *pv; if (key->is_error_expression() || key->type()->is_error_type()) { go_assert(saw_errors()); return Expression::make_error(loc); } if (key->type()->interface_type() != NULL && !key->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, key, loc); inserter->insert(temp); key = Expression::make_temporary_reference(temp, loc); } key = Expression::convert_for_assignment(gogo, key_type, key, loc); ++pv; Expression* val = *pv; if (val->is_error_expression() || val->type()->is_error_type()) { go_assert(saw_errors()); return Expression::make_error(loc); } if (val->type()->interface_type() != NULL && !val->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, val, loc); inserter->insert(temp); val = Expression::make_temporary_reference(temp, loc); } val = Expression::convert_for_assignment(gogo, val_type, val, loc); key_value_pair->push_back(key); key_value_pair->push_back(val); value_pairs->push_back( Expression::make_struct_composite_literal(this->element_type_, key_value_pair, loc)); } Expression* element_count = Expression::make_integer_ul(i, NULL, loc); Array_type* ctor_type = Type::make_array_type(this->element_type_, element_count); ctor_type->set_is_array_incomparable(); Expression* constructor = new Fixed_array_construction_expression(ctor_type, NULL, value_pairs, loc); this->constructor_temp_ = Statement::make_temporary(NULL, constructor, loc); constructor->issue_nil_check(); this->constructor_temp_->set_is_address_taken(); inserter->insert(this->constructor_temp_); } return this; } // Final type determination. void Map_construction_expression::do_determine_type(const Type_context*) { if (this->vals_ == NULL) return; Map_type* mt = this->type_->map_type(); Type_context key_context(mt->key_type(), false); Type_context val_context(mt->val_type(), false); for (Expression_list::const_iterator pv = this->vals_->begin(); pv != this->vals_->end(); ++pv) { (*pv)->determine_type(&key_context); ++pv; (*pv)->determine_type(&val_context); } } // Check types. void Map_construction_expression::do_check_types(Gogo*) { if (this->vals_ == NULL) return; Map_type* mt = this->type_->map_type(); int i = 0; Type* key_type = mt->key_type(); Type* val_type = mt->val_type(); for (Expression_list::const_iterator pv = this->vals_->begin(); pv != this->vals_->end(); ++pv, ++i) { if (!Type::are_assignable(key_type, (*pv)->type(), NULL)) { go_error_at((*pv)->location(), "incompatible type for element %d key in map construction", i + 1); this->set_is_error(); } ++pv; if (!Type::are_assignable(val_type, (*pv)->type(), NULL)) { go_error_at((*pv)->location(), ("incompatible type for element %d value " "in map construction"), i + 1); this->set_is_error(); } } } // Copy. Expression* Map_construction_expression::do_copy() { return new Map_construction_expression(this->type_->copy_expressions(), (this->vals_ == NULL ? NULL : this->vals_->copy()), this->location()); } // Make implicit type conversions explicit. void Map_construction_expression::do_add_conversions() { if (this->vals_ == NULL || this->vals_->empty()) return; Map_type* mt = this->type_->map_type(); Type* kt = mt->key_type(); Type* vt = mt->val_type(); bool key_is_interface = (kt->interface_type() != NULL); bool val_is_interface = (vt->interface_type() != NULL); if (!key_is_interface && !val_is_interface) return; Location loc = this->location(); for (Expression_list::iterator pv = this->vals_->begin(); pv != this->vals_->end(); ++pv) { if (key_is_interface && !Type::are_identical(kt, (*pv)->type(), 0, NULL)) *pv = Expression::make_cast(kt, *pv, loc); ++pv; if (val_is_interface && !Type::are_identical(vt, (*pv)->type(), 0, NULL)) *pv = Expression::make_cast(vt, *pv, loc); } } // Return the backend representation for constructing a map. Bexpression* Map_construction_expression::do_get_backend(Translate_context* context) { if (this->is_error_expression()) return context->backend()->error_expression(); Location loc = this->location(); size_t i = 0; Expression* ventries; if (this->vals_ == NULL || this->vals_->empty()) ventries = Expression::make_nil(loc); else { go_assert(this->constructor_temp_ != NULL); i = this->vals_->size() / 2; Expression* ctor_ref = Expression::make_temporary_reference(this->constructor_temp_, loc); ventries = Expression::make_unary(OPERATOR_AND, ctor_ref, loc); } Map_type* mt = this->type_->map_type(); if (this->element_type_ == NULL) this->element_type_ = Type::make_builtin_struct_type(2, "__key", mt->key_type(), "__val", mt->val_type()); Expression* descriptor = Expression::make_type_descriptor(mt, loc); Type* uintptr_t = Type::lookup_integer_type("uintptr"); Expression* count = Expression::make_integer_ul(i, uintptr_t, loc); Expression* entry_size = Expression::make_type_info(this->element_type_, TYPE_INFO_SIZE); unsigned int field_index; const Struct_field* valfield = this->element_type_->find_local_field("__val", &field_index); Expression* val_offset = Expression::make_struct_field_offset(this->element_type_, valfield); Expression* map_ctor = Runtime::make_call(Runtime::CONSTRUCT_MAP, loc, 5, descriptor, count, entry_size, val_offset, ventries); return map_ctor->get_backend(context); } // Export an array construction. void Map_construction_expression::do_export(Export_function_body* efb) const { efb->write_c_string("$convert("); efb->write_type(this->type_); for (Expression_list::const_iterator pv = this->vals_->begin(); pv != this->vals_->end(); ++pv) { efb->write_c_string(", "); (*pv)->export_expression(efb); } efb->write_c_string(")"); } // Dump ast representation for a map construction expression. void Map_construction_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "{" ; ast_dump_context->dump_expression_list(this->vals_, true); ast_dump_context->ostream() << "}"; } // A composite literal key. This is seen during parsing, but is not // resolved to a named_object in case this is a composite literal of // struct type. class Composite_literal_key_expression : public Parser_expression { public: Composite_literal_key_expression(const std::string& name, Location location) : Parser_expression(EXPRESSION_COMPOSITE_LITERAL_KEY, location), name_(name) { } const std::string& name() const { return this->name_; } protected: Expression* do_lower(Gogo*, Named_object*, Statement_inserter*, int); Expression* do_copy() { return new Composite_literal_key_expression(this->name_, this->location()); } void do_dump_expression(Ast_dump_context*) const; private: // The name. std::string name_; }; // Lower a composite literal key. We will never get here for keys in // composite literals of struct types, because that is prevented by // Composite_literal_expression::do_traverse. So if we do get here, // this must be a regular name reference after all. Expression* Composite_literal_key_expression::do_lower(Gogo* gogo, Named_object*, Statement_inserter*, int) { Named_object* no = gogo->lookup(this->name_, NULL); if (no == NULL) { // Gogo::lookup doesn't look in the global namespace, and names // used in composite literal keys aren't seen by // Gogo::define_global_names, so we have to look in the global // namespace ourselves. no = gogo->lookup_global(Gogo::unpack_hidden_name(this->name_).c_str()); if (no == NULL) { go_error_at(this->location(), "reference to undefined name %qs", Gogo::message_name(this->name_).c_str()); return Expression::make_error(this->location()); } } return Expression::make_unknown_reference(no, this->location()); } // Dump a composite literal key. void Composite_literal_key_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "_UnknownName_(" << this->name_ << ")"; } // Make a composite literal key. Expression* Expression::make_composite_literal_key(const std::string& name, Location location) { return new Composite_literal_key_expression(name, location); } // Class Composite_literal_expression. // Traversal. int Composite_literal_expression::do_traverse(Traverse* traverse) { if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; // If this is a struct composite literal with keys, then the keys // are field names, not expressions. We don't want to traverse them // in that case. If we do, we can give an erroneous error "variable // initializer refers to itself." See bug482.go in the testsuite. if (this->has_keys_ && this->vals_ != NULL) { // The type may not be resolvable at this point. Type* type = this->type_; for (int depth = 0; depth < this->depth_; ++depth) { type = type->deref(); if (type->array_type() != NULL) type = type->array_type()->element_type(); else if (type->map_type() != NULL) { if (this->key_path_[depth]) type = type->map_type()->key_type(); else type = type->map_type()->val_type(); } else { // This error will be reported during lowering. return TRAVERSE_CONTINUE; } } type = type->deref(); while (true) { if (type->classification() == Type::TYPE_NAMED) type = type->named_type()->real_type(); else if (type->classification() == Type::TYPE_FORWARD) { Type* t = type->forwarded(); if (t == type) break; type = t; } else break; } if (type->classification() == Type::TYPE_STRUCT) { Expression_list::iterator p = this->vals_->begin(); while (p != this->vals_->end()) { // Skip key. ++p; go_assert(p != this->vals_->end()); if (Expression::traverse(&*p, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; ++p; } return TRAVERSE_CONTINUE; } } if (this->vals_ != NULL) return this->vals_->traverse(traverse); return TRAVERSE_CONTINUE; } // Lower a generic composite literal into a specific version based on // the type. Expression* Composite_literal_expression::do_lower(Gogo* gogo, Named_object* function, Statement_inserter* inserter, int) { Type* type = this->type_; for (int depth = 0; depth < this->depth_; ++depth) { type = type->deref(); if (type->array_type() != NULL) type = type->array_type()->element_type(); else if (type->map_type() != NULL) { if (this->key_path_[depth]) type = type->map_type()->key_type(); else type = type->map_type()->val_type(); } else { if (!type->is_error()) go_error_at(this->location(), ("may only omit types within composite literals " "of slice, array, or map type")); return Expression::make_error(this->location()); } } Type *pt = type->points_to(); bool is_pointer = false; if (pt != NULL) { is_pointer = true; type = pt; } Expression* ret; if (type->is_error()) return Expression::make_error(this->location()); else if (type->struct_type() != NULL) ret = this->lower_struct(gogo, type); else if (type->array_type() != NULL) ret = this->lower_array(type); else if (type->map_type() != NULL) ret = this->lower_map(gogo, function, inserter, type); else { go_error_at(this->location(), ("expected struct, slice, array, or map type " "for composite literal")); return Expression::make_error(this->location()); } if (is_pointer) ret = Expression::make_heap_expression(ret, this->location()); return ret; } // Lower a struct composite literal. Expression* Composite_literal_expression::lower_struct(Gogo* gogo, Type* type) { Location location = this->location(); Struct_type* st = type->struct_type(); if (this->vals_ == NULL || !this->has_keys_) { if (this->vals_ != NULL && !this->vals_->empty() && type->named_type() != NULL && type->named_type()->named_object()->package() != NULL) { for (Struct_field_list::const_iterator pf = st->fields()->begin(); pf != st->fields()->end(); ++pf) { if (Gogo::is_hidden_name(pf->field_name()) || pf->is_embedded_builtin(gogo)) go_error_at(this->location(), "assignment of unexported field %qs in %qs literal", Gogo::message_name(pf->field_name()).c_str(), type->named_type()->message_name().c_str()); } } return new Struct_construction_expression(type, this->vals_, location); } size_t field_count = st->field_count(); std::vector vals(field_count); std::vector* traverse_order = new(std::vector); Expression_list::const_iterator p = this->vals_->begin(); Expression* external_expr = NULL; const Named_object* external_no = NULL; while (p != this->vals_->end()) { Expression* name_expr = *p; ++p; go_assert(p != this->vals_->end()); Expression* val = *p; ++p; if (name_expr == NULL) { go_error_at(val->location(), "mixture of field and value initializers"); return Expression::make_error(location); } bool bad_key = false; std::string name; const Named_object* no = NULL; switch (name_expr->classification()) { case EXPRESSION_COMPOSITE_LITERAL_KEY: name = static_cast(name_expr)->name(); break; case EXPRESSION_UNKNOWN_REFERENCE: name = name_expr->unknown_expression()->name(); if (type->named_type() != NULL) { // If the named object found for this field name comes from a // different package than the struct it is a part of, do not count // this incorrect lookup as a usage of the object's package. no = name_expr->unknown_expression()->named_object(); if (no->package() != NULL && no->package() != type->named_type()->named_object()->package()) no->package()->forget_usage(name_expr); } break; case EXPRESSION_CONST_REFERENCE: no = static_cast(name_expr)->named_object(); break; case EXPRESSION_TYPE: { Type* t = name_expr->type(); Named_type* nt = t->named_type(); if (nt == NULL) bad_key = true; else no = nt->named_object(); } break; case EXPRESSION_VAR_REFERENCE: no = name_expr->var_expression()->named_object(); break; case EXPRESSION_ENCLOSED_VAR_REFERENCE: no = name_expr->enclosed_var_expression()->variable(); break; case EXPRESSION_FUNC_REFERENCE: no = name_expr->func_expression()->named_object(); break; default: bad_key = true; break; } if (bad_key) { go_error_at(name_expr->location(), "expected struct field name"); return Expression::make_error(location); } if (no != NULL) { if (no->package() != NULL && external_expr == NULL) { external_expr = name_expr; external_no = no; } name = no->name(); // A predefined name won't be packed. If it starts with a // lower case letter we need to check for that case, because // the field name will be packed. FIXME. if (!Gogo::is_hidden_name(name) && name[0] >= 'a' && name[0] <= 'z') { Named_object* gno = gogo->lookup_global(name.c_str()); if (gno == no) name = gogo->pack_hidden_name(name, false); } } unsigned int index; const Struct_field* sf = st->find_local_field(name, &index); if (sf == NULL) { go_error_at(name_expr->location(), "unknown field %qs in %qs", Gogo::message_name(name).c_str(), (type->named_type() != NULL ? type->named_type()->message_name().c_str() : "unnamed struct")); return Expression::make_error(location); } if (vals[index] != NULL) { go_error_at(name_expr->location(), "duplicate value for field %qs in %qs", Gogo::message_name(name).c_str(), (type->named_type() != NULL ? type->named_type()->message_name().c_str() : "unnamed struct")); return Expression::make_error(location); } if (type->named_type() != NULL && type->named_type()->named_object()->package() != NULL && (Gogo::is_hidden_name(sf->field_name()) || sf->is_embedded_builtin(gogo))) go_error_at(name_expr->location(), "assignment of unexported field %qs in %qs literal", Gogo::message_name(sf->field_name()).c_str(), type->named_type()->message_name().c_str()); vals[index] = val; traverse_order->push_back(static_cast(index)); } if (!this->all_are_names_) { // This is a weird case like bug462 in the testsuite. if (external_expr == NULL) go_error_at(this->location(), "unknown field in %qs literal", (type->named_type() != NULL ? type->named_type()->message_name().c_str() : "unnamed struct")); else go_error_at(external_expr->location(), "unknown field %qs in %qs", external_no->message_name().c_str(), (type->named_type() != NULL ? type->named_type()->message_name().c_str() : "unnamed struct")); return Expression::make_error(location); } Expression_list* list = new Expression_list; list->reserve(field_count); for (size_t i = 0; i < field_count; ++i) list->push_back(vals[i]); Struct_construction_expression* ret = new Struct_construction_expression(type, list, location); ret->set_traverse_order(traverse_order); return ret; } // Index/value/traversal-order triple. struct IVT_triple { unsigned long index; unsigned long traversal_order; Expression* expr; IVT_triple(unsigned long i, unsigned long to, Expression *e) : index(i), traversal_order(to), expr(e) { } bool operator<(const IVT_triple& other) const { return this->index < other.index; } }; // Lower an array composite literal. Expression* Composite_literal_expression::lower_array(Type* type) { Location location = this->location(); if (this->vals_ == NULL || !this->has_keys_) return this->make_array(type, NULL, this->vals_); std::vector* indexes = new std::vector; indexes->reserve(this->vals_->size()); bool indexes_out_of_order = false; Expression_list* vals = new Expression_list(); vals->reserve(this->vals_->size()); unsigned long index = 0; Expression_list::const_iterator p = this->vals_->begin(); while (p != this->vals_->end()) { Expression* index_expr = *p; ++p; go_assert(p != this->vals_->end()); Expression* val = *p; ++p; if (index_expr == NULL) { if (std::find(indexes->begin(), indexes->end(), index) != indexes->end()) { go_error_at(val->location(), "duplicate value for index %lu", index); return Expression::make_error(location); } if (!indexes->empty()) indexes->push_back(index); } else { if (indexes->empty() && !vals->empty()) { for (size_t i = 0; i < vals->size(); ++i) indexes->push_back(i); } Numeric_constant nc; if (!index_expr->numeric_constant_value(&nc)) { go_error_at(index_expr->location(), "index expression is not integer constant"); return Expression::make_error(location); } switch (nc.to_unsigned_long(&index)) { case Numeric_constant::NC_UL_VALID: break; case Numeric_constant::NC_UL_NOTINT: go_error_at(index_expr->location(), "index expression is not integer constant"); return Expression::make_error(location); case Numeric_constant::NC_UL_NEGATIVE: go_error_at(index_expr->location(), "index expression is negative"); return Expression::make_error(location); case Numeric_constant::NC_UL_BIG: go_error_at(index_expr->location(), "index value overflow"); return Expression::make_error(location); default: go_unreachable(); } Named_type* ntype = Type::lookup_integer_type("int"); Integer_type* inttype = ntype->integer_type(); if (sizeof(index) <= static_cast(inttype->bits() * 8) && index >> (inttype->bits() - 1) != 0) { go_error_at(index_expr->location(), "index value overflow"); return Expression::make_error(location); } if (std::find(indexes->begin(), indexes->end(), index) != indexes->end()) { go_error_at(index_expr->location(), "duplicate value for index %lu", index); return Expression::make_error(location); } if (!indexes->empty() && index < indexes->back()) indexes_out_of_order = true; indexes->push_back(index); } vals->push_back(val); ++index; } if (indexes->empty()) { delete indexes; indexes = NULL; } std::vector* traverse_order = NULL; if (indexes_out_of_order) { typedef std::vector V; V v; v.reserve(indexes->size()); std::vector::const_iterator pi = indexes->begin(); unsigned long torder = 0; for (Expression_list::const_iterator pe = vals->begin(); pe != vals->end(); ++pe, ++pi, ++torder) v.push_back(IVT_triple(*pi, torder, *pe)); std::sort(v.begin(), v.end()); delete indexes; delete vals; indexes = new std::vector(); indexes->reserve(v.size()); vals = new Expression_list(); vals->reserve(v.size()); traverse_order = new std::vector(); traverse_order->reserve(v.size()); for (V::const_iterator pv = v.begin(); pv != v.end(); ++pv) { indexes->push_back(pv->index); vals->push_back(pv->expr); traverse_order->push_back(pv->traversal_order); } } Expression* ret = this->make_array(type, indexes, vals); Array_construction_expression* ace = ret->array_literal(); if (ace != NULL && traverse_order != NULL) ace->set_traverse_order(traverse_order); return ret; } // Actually build the array composite literal. This handles // [...]{...}. Expression* Composite_literal_expression::make_array( Type* type, const std::vector* indexes, Expression_list* vals) { Location location = this->location(); Array_type* at = type->array_type(); if (at->length() != NULL && at->length()->is_nil_expression()) { size_t size; if (vals == NULL) size = 0; else if (indexes != NULL) size = indexes->back() + 1; else { size = vals->size(); Integer_type* it = Type::lookup_integer_type("int")->integer_type(); if (sizeof(size) <= static_cast(it->bits() * 8) && size >> (it->bits() - 1) != 0) { go_error_at(location, "too many elements in composite literal"); return Expression::make_error(location); } } Expression* elen = Expression::make_integer_ul(size, NULL, location); at = Type::make_array_type(at->element_type(), elen); type = at; } else if (at->length() != NULL && !at->length()->is_error_expression() && this->vals_ != NULL) { Numeric_constant nc; unsigned long val; if (at->length()->numeric_constant_value(&nc) && nc.to_unsigned_long(&val) == Numeric_constant::NC_UL_VALID) { if (indexes == NULL) { if (this->vals_->size() > val) { go_error_at(location, "too many elements in composite literal"); return Expression::make_error(location); } } else { unsigned long max = indexes->back(); if (max >= val) { go_error_at(location, ("some element keys in composite literal " "are out of range")); return Expression::make_error(location); } } } } if (at->length() != NULL) return new Fixed_array_construction_expression(type, indexes, vals, location); else return new Slice_construction_expression(type, indexes, vals, location); } // Lower a map composite literal. Expression* Composite_literal_expression::lower_map(Gogo* gogo, Named_object* function, Statement_inserter* inserter, Type* type) { Location location = this->location(); Unordered_map(unsigned int, std::vector) st; Unordered_map(unsigned int, std::vector) nt; bool saw_false = false; bool saw_true = false; if (this->vals_ != NULL) { if (!this->has_keys_) { go_error_at(location, "map composite literal must have keys"); return Expression::make_error(location); } for (Expression_list::iterator p = this->vals_->begin(); p != this->vals_->end(); p += 2) { if (*p == NULL) { ++p; go_error_at((*p)->location(), ("map composite literal must " "have keys for every value")); return Expression::make_error(location); } // Make sure we have lowered the key; it may not have been // lowered in order to handle keys for struct composite // literals. Lower it now to get the right error message. if ((*p)->unknown_expression() != NULL) { gogo->lower_expression(function, inserter, &*p); go_assert((*p)->is_error_expression()); return Expression::make_error(location); } // Check if there are duplicate constant keys. if (!(*p)->is_constant()) continue; std::string sval; Numeric_constant nval; bool bval; if ((*p)->string_constant_value(&sval)) // Check string keys. { unsigned int h = Gogo::hash_string(sval, 0); // Search the index h in the hash map. Unordered_map(unsigned int, std::vector)::iterator mit; mit = st.find(h); if (mit == st.end()) { // No duplicate since h is a new index. // Create a new vector indexed by h and add it to the hash map. std::vector l; l.push_back(*p); std::pair > val(h, l); st.insert(val); } else { // Do further check since index h already exists. for (std::vector::iterator lit = mit->second.begin(); lit != mit->second.end(); lit++) { std::string s; bool ok = (*lit)->string_constant_value(&s); go_assert(ok); if (s == sval) { go_error_at((*p)->location(), ("duplicate key " "in map literal")); return Expression::make_error(location); } } // Add this new string key to the vector indexed by h. mit->second.push_back(*p); } } else if ((*p)->numeric_constant_value(&nval)) // Check numeric keys. { unsigned int h = nval.hash(0); Unordered_map(unsigned int, std::vector)::iterator mit; mit = nt.find(h); if (mit == nt.end()) { // No duplicate since h is a new code. // Create a new vector indexed by h and add it to the hash map. std::vector l; l.push_back(*p); std::pair > val(h, l); nt.insert(val); } else { // Do further check since h already exists. for (std::vector::iterator lit = mit->second.begin(); lit != mit->second.end(); lit++) { Numeric_constant rval; bool ok = (*lit)->numeric_constant_value(&rval); go_assert(ok); if (nval.equals(rval)) { go_error_at((*p)->location(), "duplicate key in map literal"); return Expression::make_error(location); } } // Add this new numeric key to the vector indexed by h. mit->second.push_back(*p); } } else if ((*p)->boolean_constant_value(&bval)) { if ((bval && saw_true) || (!bval && saw_false)) { go_error_at((*p)->location(), "duplicate key in map literal"); return Expression::make_error(location); } if (bval) saw_true = true; else saw_false = true; } } } return new Map_construction_expression(type, this->vals_, location); } // Copy. Expression* Composite_literal_expression::do_copy() { Composite_literal_expression* ret = new Composite_literal_expression(this->type_->copy_expressions(), this->depth_, this->has_keys_, (this->vals_ == NULL ? NULL : this->vals_->copy()), this->all_are_names_, this->location()); ret->key_path_ = this->key_path_; return ret; } // Dump ast representation for a composite literal expression. void Composite_literal_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "composite("; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << ", {"; ast_dump_context->dump_expression_list(this->vals_, this->has_keys_); ast_dump_context->ostream() << "})"; } // Make a composite literal expression. Expression* Expression::make_composite_literal(Type* type, int depth, bool has_keys, Expression_list* vals, bool all_are_names, Location location) { return new Composite_literal_expression(type, depth, has_keys, vals, all_are_names, location); } // Return whether this expression is a composite literal. bool Expression::is_composite_literal() const { switch (this->classification_) { case EXPRESSION_COMPOSITE_LITERAL: case EXPRESSION_STRUCT_CONSTRUCTION: case EXPRESSION_FIXED_ARRAY_CONSTRUCTION: case EXPRESSION_SLICE_CONSTRUCTION: case EXPRESSION_MAP_CONSTRUCTION: return true; default: return false; } } // Return whether this expression is a composite literal which is not // constant. bool Expression::is_nonconstant_composite_literal() const { switch (this->classification_) { case EXPRESSION_STRUCT_CONSTRUCTION: { const Struct_construction_expression *psce = static_cast(this); return !psce->is_constant_struct(); } case EXPRESSION_FIXED_ARRAY_CONSTRUCTION: { const Fixed_array_construction_expression *pace = static_cast(this); return !pace->is_constant_array(); } case EXPRESSION_SLICE_CONSTRUCTION: { const Slice_construction_expression *pace = static_cast(this); return !pace->is_constant_array(); } case EXPRESSION_MAP_CONSTRUCTION: return true; default: return false; } } // Return true if this is a variable or temporary_variable. bool Expression::is_variable() const { switch (this->classification_) { case EXPRESSION_VAR_REFERENCE: case EXPRESSION_TEMPORARY_REFERENCE: case EXPRESSION_SET_AND_USE_TEMPORARY: case EXPRESSION_ENCLOSED_VAR_REFERENCE: return true; default: return false; } } // Return true if this is a reference to a local variable. bool Expression::is_local_variable() const { const Var_expression* ve = this->var_expression(); if (ve == NULL) return false; const Named_object* no = ve->named_object(); return (no->is_result_variable() || (no->is_variable() && !no->var_value()->is_global())); } // Return true if multiple evaluations are OK. bool Expression::is_multi_eval_safe() { switch (this->classification_) { case EXPRESSION_VAR_REFERENCE: { // A variable is a simple reference if not stored in the heap. const Named_object* no = this->var_expression()->named_object(); if (no->is_variable()) return !no->var_value()->is_in_heap(); else if (no->is_result_variable()) return !no->result_var_value()->is_in_heap(); else go_unreachable(); } case EXPRESSION_TEMPORARY_REFERENCE: return true; default: break; } if (!this->is_constant()) return false; // Only numeric and boolean constants are really multi-evaluation // safe. We don't want multiple copies of string constants. Type* type = this->type(); return type->is_numeric_type() || type->is_boolean_type(); } const Named_object* Expression::named_constant() const { if (this->classification() != EXPRESSION_CONST_REFERENCE) return NULL; const Const_expression* ce = static_cast(this); return ce->named_object(); } // Class Type_guard_expression. // Traversal. int Type_guard_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } Expression* Type_guard_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { if (this->expr_->is_error_expression() || this->expr_->type()->is_error_type()) { go_assert(saw_errors()); return Expression::make_error(this->location()); } if (!this->expr_->is_multi_eval_safe()) { Temporary_statement* temp = Statement::make_temporary(NULL, this->expr_, this->location()); inserter->insert(temp); this->expr_ = Expression::make_temporary_reference(temp, this->location()); } return this; } // Check types of a type guard expression. The expression must have // an interface type, but the actual type conversion is checked at run // time. void Type_guard_expression::do_check_types(Gogo*) { Type* expr_type = this->expr_->type(); if (expr_type->interface_type() == NULL) { if (!expr_type->is_error() && !this->type_->is_error()) this->report_error(_("type assertion only valid for interface types")); this->set_is_error(); } else if (this->type_->interface_type() == NULL) { std::string reason; if (!expr_type->interface_type()->implements_interface(this->type_, &reason)) { if (!this->type_->is_error()) { if (reason.empty()) this->report_error(_("impossible type assertion: " "type does not implement interface")); else go_error_at(this->location(), ("impossible type assertion: " "type does not implement interface (%s)"), reason.c_str()); } this->set_is_error(); } } } // Copy. Expression* Type_guard_expression::do_copy() { return new Type_guard_expression(this->expr_->copy(), this->type_->copy_expressions(), this->location()); } // Return the backend representation for a type guard expression. Bexpression* Type_guard_expression::do_get_backend(Translate_context* context) { Expression* conversion; if (this->type_->interface_type() != NULL) conversion = Expression::convert_interface_to_interface(this->type_, this->expr_, true, this->location()); else conversion = Expression::convert_for_assignment(context->gogo(), this->type_, this->expr_, this->location()); Gogo* gogo = context->gogo(); Btype* bt = this->type_->get_backend(gogo); Bexpression* bexpr = conversion->get_backend(context); return gogo->backend()->convert_expression(bt, bexpr, this->location()); } // Dump ast representation for a type guard expression. void Type_guard_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { this->expr_->dump_expression(ast_dump_context); ast_dump_context->ostream() << "."; ast_dump_context->dump_type(this->type_); } // Make a type guard expression. Expression* Expression::make_type_guard(Expression* expr, Type* type, Location location) { return new Type_guard_expression(expr, type, location); } // Class Heap_expression. // Return the type of the expression stored on the heap. Type* Heap_expression::do_type() { return Type::make_pointer_type(this->expr_->type()); } // Return the backend representation for allocating an expression on the heap. Bexpression* Heap_expression::do_get_backend(Translate_context* context) { Type* etype = this->expr_->type(); if (this->expr_->is_error_expression() || etype->is_error()) return context->backend()->error_expression(); Location loc = this->location(); Gogo* gogo = context->gogo(); Btype* btype = this->type()->get_backend(gogo); Expression* alloc = Expression::make_allocation(etype, loc); if (this->allocate_on_stack_) alloc->allocation_expression()->set_allocate_on_stack(); Bexpression* space = alloc->get_backend(context); Bstatement* decl; Named_object* fn = context->function(); go_assert(fn != NULL); Bfunction* fndecl = fn->func_value()->get_or_make_decl(gogo, fn); Bvariable* space_temp = gogo->backend()->temporary_variable(fndecl, context->bblock(), btype, space, Backend::variable_address_is_taken, loc, &decl); Btype* expr_btype = etype->get_backend(gogo); Bexpression* bexpr = this->expr_->get_backend(context); // If this assignment needs a write barrier, call typedmemmove. We // don't do this in the write barrier pass because in some cases // backend conversion can introduce new Heap_expression values. Bstatement* assn; if (!etype->has_pointer() || this->allocate_on_stack_) { space = gogo->backend()->var_expression(space_temp, loc); Bexpression* ref = gogo->backend()->indirect_expression(expr_btype, space, true, loc); assn = gogo->backend()->assignment_statement(fndecl, ref, bexpr, loc); } else { Bstatement* edecl; Bvariable* btemp = gogo->backend()->temporary_variable(fndecl, context->bblock(), expr_btype, bexpr, Backend::variable_address_is_taken, loc, &edecl); Bexpression* btempref = gogo->backend()->var_expression(btemp, loc); space = gogo->backend()->var_expression(space_temp, loc); Type* etype_ptr = Type::make_pointer_type(etype); Expression* elhs = Expression::make_backend(space, etype_ptr, loc); Expression* erhs; Expression* call; if (etype->is_direct_iface_type()) { // Single pointer. Type* uintptr_type = Type::lookup_integer_type("uintptr"); erhs = Expression::make_backend(btempref, etype, loc); erhs = Expression::unpack_direct_iface(erhs, loc); erhs = Expression::make_unsafe_cast(uintptr_type, erhs, loc); call = Runtime::make_call(Runtime::GCWRITEBARRIER, loc, 2, elhs, erhs); } else { Expression* td = Expression::make_type_descriptor(etype, loc); Bexpression* addr = gogo->backend()->address_expression(btempref, loc); erhs = Expression::make_backend(addr, etype_ptr, loc); call = Runtime::make_call(Runtime::TYPEDMEMMOVE, loc, 3, td, elhs, erhs); } Statement* cs = Statement::make_statement(call, false); space = gogo->backend()->var_expression(space_temp, loc); Bexpression* ref = gogo->backend()->indirect_expression(expr_btype, space, true, loc); Expression* eref = Expression::make_backend(ref, etype, loc); btempref = gogo->backend()->var_expression(btemp, loc); erhs = Expression::make_backend(btempref, etype, loc); Statement* as = Statement::make_assignment(eref, erhs, loc); as = gogo->check_write_barrier(context->block(), as, cs); Bstatement* s = as->get_backend(context); assn = gogo->backend()->compound_statement(edecl, s); } decl = gogo->backend()->compound_statement(decl, assn); space = gogo->backend()->var_expression(space_temp, loc); return gogo->backend()->compound_expression(decl, space, loc); } // Dump ast representation for a heap expression. void Heap_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "&("; ast_dump_context->dump_expression(this->expr_); ast_dump_context->ostream() << ")"; } // Allocate an expression on the heap. Expression* Expression::make_heap_expression(Expression* expr, Location location) { return new Heap_expression(expr, location); } // Class Receive_expression. // Return the type of a receive expression. Type* Receive_expression::do_type() { if (this->is_error_expression()) return Type::make_error_type(); Channel_type* channel_type = this->channel_->type()->channel_type(); if (channel_type == NULL) { this->report_error(_("expected channel")); return Type::make_error_type(); } return channel_type->element_type(); } // Check types for a receive expression. void Receive_expression::do_check_types(Gogo*) { Type* type = this->channel_->type(); if (type->is_error()) { go_assert(saw_errors()); this->set_is_error(); return; } if (type->channel_type() == NULL) { this->report_error(_("expected channel")); return; } if (!type->channel_type()->may_receive()) { this->report_error(_("invalid receive on send-only channel")); return; } } // Flattening for receive expressions creates a temporary variable to store // received data in for receives. Expression* Receive_expression::do_flatten(Gogo*, Named_object*, Statement_inserter* inserter) { Channel_type* channel_type = this->channel_->type()->channel_type(); if (channel_type == NULL) { go_assert(saw_errors()); return this; } else if (this->channel_->is_error_expression()) { go_assert(saw_errors()); return Expression::make_error(this->location()); } Type* element_type = channel_type->element_type(); if (this->temp_receiver_ == NULL) { this->temp_receiver_ = Statement::make_temporary(element_type, NULL, this->location()); this->temp_receiver_->set_is_address_taken(); inserter->insert(this->temp_receiver_); } return this; } // Get the backend representation for a receive expression. Bexpression* Receive_expression::do_get_backend(Translate_context* context) { Location loc = this->location(); Channel_type* channel_type = this->channel_->type()->channel_type(); if (channel_type == NULL) { go_assert(this->channel_->type()->is_error()); return context->backend()->error_expression(); } Expression* recv_ref = Expression::make_temporary_reference(this->temp_receiver_, loc); Expression* recv_addr = Expression::make_temporary_reference(this->temp_receiver_, loc); recv_addr = Expression::make_unary(OPERATOR_AND, recv_addr, loc); Expression* recv = Runtime::make_call(Runtime::CHANRECV1, loc, 2, this->channel_, recv_addr); return Expression::make_compound(recv, recv_ref, loc)->get_backend(context); } // Export a receive expression. void Receive_expression::do_export(Export_function_body* efb) const { efb->write_c_string("<-"); this->channel_->export_expression(efb); } // Dump ast representation for a receive expression. void Receive_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << " <- " ; ast_dump_context->dump_expression(channel_); } // Import a receive expression. Expression* Receive_expression::do_import(Import_expression* imp, Location loc) { imp->require_c_string("<-"); Expression* expr = Expression::import_expression(imp, loc); return Expression::make_receive(expr, loc); } // Make a receive expression. Receive_expression* Expression::make_receive(Expression* channel, Location location) { return new Receive_expression(channel, location); } // An expression which evaluates to a pointer to the type descriptor // of a type. class Type_descriptor_expression : public Expression { public: Type_descriptor_expression(Type* type, Location location) : Expression(EXPRESSION_TYPE_DESCRIPTOR, location), type_(type) { } protected: int do_traverse(Traverse*); Type* do_type() { return Type::make_type_descriptor_ptr_type(); } bool do_is_static_initializer() const { return true; } void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context* context) { return this->type_->type_descriptor_pointer(context->gogo(), this->location()); } void do_dump_expression(Ast_dump_context*) const; private: // The type for which this is the descriptor. Type* type_; }; int Type_descriptor_expression::do_traverse(Traverse* traverse) { if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Dump ast representation for a type descriptor expression. void Type_descriptor_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->dump_type(this->type_); } // Make a type descriptor expression. Expression* Expression::make_type_descriptor(Type* type, Location location) { return new Type_descriptor_expression(type, location); } // An expression which evaluates to a pointer to the Garbage Collection symbol // of a type. class GC_symbol_expression : public Expression { public: GC_symbol_expression(Type* type) : Expression(EXPRESSION_GC_SYMBOL, Linemap::predeclared_location()), type_(type) {} protected: Type* do_type() { return Type::make_pointer_type(Type::lookup_integer_type("uint8")); } bool do_is_static_initializer() const { return true; } void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context* context) { return this->type_->gc_symbol_pointer(context->gogo()); } void do_dump_expression(Ast_dump_context*) const; private: // The type which this gc symbol describes. Type* type_; }; // Dump ast representation for a gc symbol expression. void GC_symbol_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "gcdata("; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << ")"; } // Make a gc symbol expression. Expression* Expression::make_gc_symbol(Type* type) { return new GC_symbol_expression(type); } // An expression that evaluates to a pointer to a symbol holding the // ptrmask data of a type. class Ptrmask_symbol_expression : public Expression { public: Ptrmask_symbol_expression(Type* type) : Expression(EXPRESSION_PTRMASK_SYMBOL, Linemap::predeclared_location()), type_(type) {} protected: Type* do_type() { return Type::make_pointer_type(Type::lookup_integer_type("uint8")); } bool do_is_static_initializer() const { return true; } void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context*); void do_dump_expression(Ast_dump_context*) const; private: // The type that this ptrmask symbol describes. Type* type_; }; // Return the ptrmask variable. Bexpression* Ptrmask_symbol_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); // If this type does not need a gcprog, then we can use the standard // GC symbol. int64_t ptrsize, ptrdata; if (!this->type_->needs_gcprog(gogo, &ptrsize, &ptrdata)) return this->type_->gc_symbol_pointer(gogo); // Otherwise we have to build a ptrmask variable, and return a // pointer to it. Bvariable* bvar = this->type_->gc_ptrmask_var(gogo, ptrsize, ptrdata); Location bloc = Linemap::predeclared_location(); Bexpression* bref = gogo->backend()->var_expression(bvar, bloc); Bexpression* baddr = gogo->backend()->address_expression(bref, bloc); Type* uint8_type = Type::lookup_integer_type("uint8"); Type* pointer_uint8_type = Type::make_pointer_type(uint8_type); Btype* ubtype = pointer_uint8_type->get_backend(gogo); return gogo->backend()->convert_expression(ubtype, baddr, bloc); } // Dump AST for a ptrmask symbol expression. void Ptrmask_symbol_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "ptrmask("; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << ")"; } // Make a ptrmask symbol expression. Expression* Expression::make_ptrmask_symbol(Type* type) { return new Ptrmask_symbol_expression(type); } // An expression which evaluates to some characteristic of a type. // This is only used to initialize fields of a type descriptor. Using // a new expression class is slightly inefficient but gives us a good // separation between the frontend and the middle-end with regard to // how types are laid out. class Type_info_expression : public Expression { public: Type_info_expression(Type* type, Type_info type_info) : Expression(EXPRESSION_TYPE_INFO, Linemap::predeclared_location()), type_(type), type_info_(type_info) { } protected: bool do_is_static_initializer() const { return true; } Type* do_type(); void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; private: // The type for which we are getting information. Type* type_; // What information we want. Type_info type_info_; }; // The type is chosen to match what the type descriptor struct // expects. Type* Type_info_expression::do_type() { switch (this->type_info_) { case TYPE_INFO_SIZE: case TYPE_INFO_BACKEND_PTRDATA: case TYPE_INFO_DESCRIPTOR_PTRDATA: return Type::lookup_integer_type("uintptr"); case TYPE_INFO_ALIGNMENT: case TYPE_INFO_FIELD_ALIGNMENT: return Type::lookup_integer_type("uint8"); default: go_unreachable(); } } // Return the backend representation for type information. Bexpression* Type_info_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); bool ok = true; int64_t val; switch (this->type_info_) { case TYPE_INFO_SIZE: ok = this->type_->backend_type_size(gogo, &val); break; case TYPE_INFO_ALIGNMENT: ok = this->type_->backend_type_align(gogo, &val); break; case TYPE_INFO_FIELD_ALIGNMENT: ok = this->type_->backend_type_field_align(gogo, &val); break; case TYPE_INFO_BACKEND_PTRDATA: ok = this->type_->backend_type_ptrdata(gogo, &val); break; case TYPE_INFO_DESCRIPTOR_PTRDATA: ok = this->type_->descriptor_ptrdata(gogo, &val); break; default: go_unreachable(); } if (!ok) { go_assert(saw_errors()); return gogo->backend()->error_expression(); } Expression* e = Expression::make_integer_int64(val, this->type(), this->location()); return e->get_backend(context); } // Dump ast representation for a type info expression. void Type_info_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "typeinfo("; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << ","; ast_dump_context->ostream() << (this->type_info_ == TYPE_INFO_ALIGNMENT ? "alignment" : this->type_info_ == TYPE_INFO_FIELD_ALIGNMENT ? "field alignment" : this->type_info_ == TYPE_INFO_SIZE ? "size" : this->type_info_ == TYPE_INFO_BACKEND_PTRDATA ? "backend_ptrdata" : this->type_info_ == TYPE_INFO_DESCRIPTOR_PTRDATA ? "descriptor_ptrdata" : "unknown"); ast_dump_context->ostream() << ")"; } // Make a type info expression. Expression* Expression::make_type_info(Type* type, Type_info type_info) { return new Type_info_expression(type, type_info); } // Slice_info_expression. // Return the type of the slice info. Type* Slice_info_expression::do_type() { switch (this->slice_info_) { case SLICE_INFO_VALUE_POINTER: return Type::make_pointer_type( this->slice_->type()->array_type()->element_type()); case SLICE_INFO_LENGTH: case SLICE_INFO_CAPACITY: return Type::lookup_integer_type("int"); default: go_unreachable(); } } // Return the backend information for slice information. Bexpression* Slice_info_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Bexpression* bslice = this->slice_->get_backend(context); switch (this->slice_info_) { case SLICE_INFO_VALUE_POINTER: case SLICE_INFO_LENGTH: case SLICE_INFO_CAPACITY: return gogo->backend()->struct_field_expression(bslice, this->slice_info_, this->location()); break; default: go_unreachable(); } } // Dump ast representation for a type info expression. void Slice_info_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "sliceinfo("; this->slice_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ","; ast_dump_context->ostream() << (this->slice_info_ == SLICE_INFO_VALUE_POINTER ? "values" : this->slice_info_ == SLICE_INFO_LENGTH ? "length" : this->slice_info_ == SLICE_INFO_CAPACITY ? "capacity " : "unknown"); ast_dump_context->ostream() << ")"; } // Make a slice info expression. Expression* Expression::make_slice_info(Expression* slice, Slice_info slice_info, Location location) { return new Slice_info_expression(slice, slice_info, location); } // Class Slice_value_expression. int Slice_value_expression::do_traverse(Traverse* traverse) { if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->valmem_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->len_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->cap_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Determine type of a slice value. void Slice_value_expression::do_determine_type(const Type_context*) { this->valmem_->determine_type_no_context(); this->len_->determine_type_no_context(); this->cap_->determine_type_no_context(); } Expression* Slice_value_expression::do_copy() { return new Slice_value_expression(this->type_->copy_expressions(), this->valmem_->copy(), this->len_->copy(), this->cap_->copy(), this->location()); } Bexpression* Slice_value_expression::do_get_backend(Translate_context* context) { std::vector vals(3); vals[0] = this->valmem_->get_backend(context); vals[1] = this->len_->get_backend(context); vals[2] = this->cap_->get_backend(context); Gogo* gogo = context->gogo(); Btype* btype = this->type_->get_backend(gogo); return gogo->backend()->constructor_expression(btype, vals, this->location()); } void Slice_value_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "slicevalue("; ast_dump_context->ostream() << "values: "; this->valmem_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ", length: "; this->len_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ", capacity: "; this->cap_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ")"; } Expression* Expression::make_slice_value(Type* at, Expression* valmem, Expression* len, Expression* cap, Location location) { go_assert(at->is_slice_type()); go_assert(valmem->is_nil_expression() || (at->array_type()->element_type() == valmem->type()->points_to())); return new Slice_value_expression(at, valmem, len, cap, location); } // Look through the expression of a Slice_value_expression's valmem to // find an call to makeslice. If found, return the call expression and // the containing temporary statement (if any). std::pair Expression::find_makeslice_call(Expression* expr) { Unsafe_type_conversion_expression* utce = expr->unsafe_conversion_expression(); if (utce != NULL) expr = utce->expr(); Slice_value_expression* sve = expr->slice_value_expression(); if (sve == NULL) return std::make_pair(NULL, NULL); expr = sve->valmem(); utce = expr->unsafe_conversion_expression(); if (utce != NULL) expr = utce->expr(); Temporary_reference_expression* tre = expr->temporary_reference_expression(); Temporary_statement* ts = (tre != NULL ? tre->statement() : NULL); if (ts != NULL && ts->init() != NULL && !ts->assigned() && !ts->is_address_taken()) expr = ts->init(); Call_expression* call = expr->call_expression(); if (call == NULL) return std::make_pair(NULL, NULL); Func_expression* fe = call->fn()->func_expression(); if (fe != NULL && fe->runtime_code() == Runtime::MAKESLICE) return std::make_pair(call, ts); return std::make_pair(NULL, NULL); } // An expression that evaluates to some characteristic of a non-empty interface. // This is used to access the method table or underlying object of an interface. class Interface_info_expression : public Expression { public: Interface_info_expression(Expression* iface, Interface_info iface_info, Location location) : Expression(EXPRESSION_INTERFACE_INFO, location), iface_(iface), iface_info_(iface_info) { } protected: Type* do_type(); void do_determine_type(const Type_context*) { } Expression* do_copy() { return new Interface_info_expression(this->iface_->copy(), this->iface_info_, this->location()); } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; void do_issue_nil_check() { this->iface_->issue_nil_check(); } private: // The interface for which we are getting information. Expression* iface_; // What information we want. Interface_info iface_info_; }; // Return the type of the interface info. Type* Interface_info_expression::do_type() { switch (this->iface_info_) { case INTERFACE_INFO_METHODS: { typedef Unordered_map(Interface_type*, Type*) Hashtable; static Hashtable result_types; Interface_type* itype = this->iface_->type()->interface_type(); Hashtable::const_iterator pr = result_types.find(itype); if (pr != result_types.end()) return pr->second; Type* pdt = Type::make_type_descriptor_ptr_type(); if (itype->is_empty()) { result_types[itype] = pdt; return pdt; } Location loc = this->location(); Struct_field_list* sfl = new Struct_field_list(); sfl->push_back( Struct_field(Typed_identifier("__type_descriptor", pdt, loc))); for (Typed_identifier_list::const_iterator p = itype->methods()->begin(); p != itype->methods()->end(); ++p) { Function_type* ft = p->type()->function_type(); go_assert(ft->receiver() == NULL); const Typed_identifier_list* params = ft->parameters(); Typed_identifier_list* mparams = new Typed_identifier_list(); if (params != NULL) mparams->reserve(params->size() + 1); Type* vt = Type::make_pointer_type(Type::make_void_type()); mparams->push_back(Typed_identifier("", vt, ft->location())); if (params != NULL) { for (Typed_identifier_list::const_iterator pp = params->begin(); pp != params->end(); ++pp) mparams->push_back(*pp); } Typed_identifier_list* mresults = (ft->results() == NULL ? NULL : ft->results()->copy()); Backend_function_type* mft = Type::make_backend_function_type(NULL, mparams, mresults, ft->location()); std::string fname = Gogo::unpack_hidden_name(p->name()); sfl->push_back(Struct_field(Typed_identifier(fname, mft, loc))); } Struct_type* st = Type::make_struct_type(sfl, loc); st->set_is_struct_incomparable(); Pointer_type *pt = Type::make_pointer_type(st); result_types[itype] = pt; return pt; } case INTERFACE_INFO_OBJECT: return Type::make_pointer_type(Type::make_void_type()); default: go_unreachable(); } } // Return the backend representation for interface information. Bexpression* Interface_info_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Bexpression* biface = this->iface_->get_backend(context); switch (this->iface_info_) { case INTERFACE_INFO_METHODS: case INTERFACE_INFO_OBJECT: return gogo->backend()->struct_field_expression(biface, this->iface_info_, this->location()); break; default: go_unreachable(); } } // Dump ast representation for an interface info expression. void Interface_info_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { bool is_empty = this->iface_->type()->interface_type()->is_empty(); ast_dump_context->ostream() << "interfaceinfo("; this->iface_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ","; ast_dump_context->ostream() << (this->iface_info_ == INTERFACE_INFO_METHODS && !is_empty ? "methods" : this->iface_info_ == INTERFACE_INFO_TYPE_DESCRIPTOR ? "type_descriptor" : this->iface_info_ == INTERFACE_INFO_OBJECT ? "object" : "unknown"); ast_dump_context->ostream() << ")"; } // Make an interface info expression. Expression* Expression::make_interface_info(Expression* iface, Interface_info iface_info, Location location) { return new Interface_info_expression(iface, iface_info, location); } // An expression that represents an interface value. The first field is either // a type descriptor for an empty interface or a pointer to the interface method // table for a non-empty interface. The second field is always the object. class Interface_value_expression : public Expression { public: Interface_value_expression(Type* type, Expression* first_field, Expression* obj, Location location) : Expression(EXPRESSION_INTERFACE_VALUE, location), type_(type), first_field_(first_field), obj_(obj) { } protected: int do_traverse(Traverse*); Type* do_type() { return this->type_; } void do_determine_type(const Type_context*) { go_unreachable(); } Expression* do_copy() { return new Interface_value_expression(this->type_->copy_expressions(), this->first_field_->copy(), this->obj_->copy(), this->location()); } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; private: // The type of the interface value. Type* type_; // The first field of the interface (either a type descriptor or a pointer // to the method table. Expression* first_field_; // The underlying object of the interface. Expression* obj_; }; int Interface_value_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->first_field_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->obj_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } Bexpression* Interface_value_expression::do_get_backend(Translate_context* context) { std::vector vals(2); vals[0] = this->first_field_->get_backend(context); vals[1] = this->obj_->get_backend(context); Gogo* gogo = context->gogo(); Btype* btype = this->type_->get_backend(gogo); return gogo->backend()->constructor_expression(btype, vals, this->location()); } void Interface_value_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "interfacevalue("; ast_dump_context->ostream() << (this->type_->interface_type()->is_empty() ? "type_descriptor: " : "methods: "); this->first_field_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ", object: "; this->obj_->dump_expression(ast_dump_context); ast_dump_context->ostream() << ")"; } Expression* Expression::make_interface_value(Type* type, Expression* first_value, Expression* object, Location location) { return new Interface_value_expression(type, first_value, object, location); } // An interface method table for a pair of types: an interface type and a type // that implements that interface. class Interface_mtable_expression : public Expression { public: Interface_mtable_expression(Interface_type* itype, Type* type, bool is_pointer, Location location) : Expression(EXPRESSION_INTERFACE_MTABLE, location), itype_(itype), type_(type), is_pointer_(is_pointer), method_table_type_(NULL), bvar_(NULL) { } protected: int do_traverse(Traverse*); Type* do_type(); bool do_is_static_initializer() const { return true; } void do_determine_type(const Type_context*) { go_unreachable(); } Expression* do_copy() { Interface_type* itype = this->itype_->copy_expressions()->interface_type(); return new Interface_mtable_expression(itype, this->type_->copy_expressions(), this->is_pointer_, this->location()); } bool do_is_addressable() const { return true; } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; private: // The interface type for which the methods are defined. Interface_type* itype_; // The type to construct the interface method table for. Type* type_; // Whether this table contains the method set for the receiver type or the // pointer receiver type. bool is_pointer_; // The type of the method table. Type* method_table_type_; // The backend variable that refers to the interface method table. Bvariable* bvar_; }; int Interface_mtable_expression::do_traverse(Traverse* traverse) { if (Type::traverse(this->itype_, traverse) == TRAVERSE_EXIT || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } Type* Interface_mtable_expression::do_type() { if (this->method_table_type_ != NULL) return this->method_table_type_; const Typed_identifier_list* interface_methods = this->itype_->methods(); go_assert(!interface_methods->empty()); Struct_field_list* sfl = new Struct_field_list; Typed_identifier tid("__type_descriptor", Type::make_type_descriptor_ptr_type(), this->location()); sfl->push_back(Struct_field(tid)); Type* unsafe_ptr_type = Type::make_pointer_type(Type::make_void_type()); for (Typed_identifier_list::const_iterator p = interface_methods->begin(); p != interface_methods->end(); ++p) { // We want C function pointers here, not func descriptors; model // using void* pointers. Typed_identifier method(p->name(), unsafe_ptr_type, p->location()); sfl->push_back(Struct_field(method)); } Struct_type* st = Type::make_struct_type(sfl, this->location()); st->set_is_struct_incomparable(); this->method_table_type_ = st; return this->method_table_type_; } Bexpression* Interface_mtable_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Location loc = Linemap::predeclared_location(); if (this->bvar_ != NULL) return gogo->backend()->var_expression(this->bvar_, this->location()); const Typed_identifier_list* interface_methods = this->itype_->methods(); go_assert(!interface_methods->empty()); std::string mangled_name = gogo->interface_method_table_name(this->itype_, this->type_, this->is_pointer_); // Set is_public if we are converting a named type to an interface // type that is defined in the same package as the named type, and // the interface has hidden methods. In that case the interface // method table will be defined by the package that defines the // types. bool is_public = false; if (this->type_->named_type() != NULL && (this->type_->named_type()->named_object()->package() == this->itype_->package())) { for (Typed_identifier_list::const_iterator p = interface_methods->begin(); p != interface_methods->end(); ++p) { if (Gogo::is_hidden_name(p->name())) { is_public = true; break; } } } if (is_public && this->type_->named_type()->named_object()->package() != NULL) { // The interface conversion table is defined elsewhere. Btype* btype = this->type()->get_backend(gogo); this->bvar_ = gogo->backend()->immutable_struct_reference(mangled_name, "", btype, loc); return gogo->backend()->var_expression(this->bvar_, this->location()); } // The first element is the type descriptor. Type* td_type; if (!this->is_pointer_) td_type = this->type_; else td_type = Type::make_pointer_type(this->type_); std::vector bstructfields; // Build an interface method table for a type: a type descriptor followed by a // list of function pointers, one for each interface method. This is used for // interfaces. Expression_list* svals = new Expression_list(); Expression* tdescriptor = Expression::make_type_descriptor(td_type, loc); svals->push_back(tdescriptor); Btype* tdesc_btype = tdescriptor->type()->get_backend(gogo); Backend::Btyped_identifier btd("_type", tdesc_btype, loc); bstructfields.push_back(btd); Named_type* nt = this->type_->named_type(); Struct_type* st = this->type_->struct_type(); go_assert(nt != NULL || st != NULL); for (Typed_identifier_list::const_iterator p = interface_methods->begin(); p != interface_methods->end(); ++p) { bool is_ambiguous; Method* m; if (nt != NULL) m = nt->method_function(p->name(), &is_ambiguous); else m = st->method_function(p->name(), &is_ambiguous); go_assert(m != NULL); // See the comment in Type::method_constructor. bool use_direct_iface_stub = false; if (m->is_value_method() && this->is_pointer_ && this->type_->is_direct_iface_type()) use_direct_iface_stub = true; if (!m->is_value_method() && this->is_pointer_ && !this->type_->in_heap()) use_direct_iface_stub = true; Named_object* no = (use_direct_iface_stub ? m->iface_stub_object() : m->named_object()); go_assert(no->is_function() || no->is_function_declaration()); Function_type* fcn_type = (no->is_function() ? no->func_value()->type() : no->func_declaration_value()->type()); Btype* fcn_btype = fcn_type->get_backend_fntype(gogo); Backend::Btyped_identifier bmtype(p->name(), fcn_btype, loc); bstructfields.push_back(bmtype); svals->push_back(Expression::make_func_code_reference(no, loc)); } Btype *btype = gogo->backend()->struct_type(bstructfields); std::vector ctor_bexprs; for (Expression_list::const_iterator pe = svals->begin(); pe != svals->end(); ++pe) { ctor_bexprs.push_back((*pe)->get_backend(context)); } Bexpression* ctor = gogo->backend()->constructor_expression(btype, ctor_bexprs, loc); unsigned int flags = 0; if (!is_public) flags |= Backend::variable_is_hidden; this->bvar_ = gogo->backend()->immutable_struct(mangled_name, "", flags, btype, loc); gogo->backend()->immutable_struct_set_init(this->bvar_, mangled_name, flags, btype, loc, ctor); return gogo->backend()->var_expression(this->bvar_, loc); } void Interface_mtable_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "__go_" << (this->is_pointer_ ? "pimt__" : "imt_"); ast_dump_context->dump_type(this->itype_); ast_dump_context->ostream() << "__"; ast_dump_context->dump_type(this->type_); } Expression* Expression::make_interface_mtable_ref(Interface_type* itype, Type* type, bool is_pointer, Location location) { return new Interface_mtable_expression(itype, type, is_pointer, location); } // An expression which evaluates to the offset of a field within a // struct. This, like Type_info_expression, q.v., is only used to // initialize fields of a type descriptor. class Struct_field_offset_expression : public Expression { public: Struct_field_offset_expression(Struct_type* type, const Struct_field* field) : Expression(EXPRESSION_STRUCT_FIELD_OFFSET, Linemap::predeclared_location()), type_(type), field_(field) { } protected: bool do_is_static_initializer() const { return true; } Type* do_type() { return Type::lookup_integer_type("uintptr"); } void do_determine_type(const Type_context*) { } Expression* do_copy() { return this; } Bexpression* do_get_backend(Translate_context* context); void do_dump_expression(Ast_dump_context*) const; private: // The type of the struct. Struct_type* type_; // The field. const Struct_field* field_; }; // Return the backend representation for a struct field offset. Bexpression* Struct_field_offset_expression::do_get_backend(Translate_context* context) { const Struct_field_list* fields = this->type_->fields(); Struct_field_list::const_iterator p; unsigned i = 0; for (p = fields->begin(); p != fields->end(); ++p, ++i) if (&*p == this->field_) break; go_assert(&*p == this->field_); Gogo* gogo = context->gogo(); Btype* btype = this->type_->get_backend(gogo); int64_t offset = gogo->backend()->type_field_offset(btype, i); Type* uptr_type = Type::lookup_integer_type("uintptr"); Expression* ret = Expression::make_integer_int64(offset, uptr_type, Linemap::predeclared_location()); return ret->get_backend(context); } // Dump ast representation for a struct field offset expression. void Struct_field_offset_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "unsafe.Offsetof("; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << '.'; ast_dump_context->ostream() << Gogo::message_name(this->field_->field_name()); ast_dump_context->ostream() << ")"; } // Make an expression for a struct field offset. Expression* Expression::make_struct_field_offset(Struct_type* type, const Struct_field* field) { return new Struct_field_offset_expression(type, field); } // An expression which evaluates to the address of an unnamed label. class Label_addr_expression : public Expression { public: Label_addr_expression(Label* label, Location location) : Expression(EXPRESSION_LABEL_ADDR, location), label_(label) { } protected: Type* do_type() { return Type::make_pointer_type(Type::make_void_type()); } void do_determine_type(const Type_context*) { } Expression* do_copy() { return new Label_addr_expression(this->label_, this->location()); } Bexpression* do_get_backend(Translate_context* context) { return this->label_->get_addr(context, this->location()); } void do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << this->label_->name(); } private: // The label whose address we are taking. Label* label_; }; // Make an expression for the address of an unnamed label. Expression* Expression::make_label_addr(Label* label, Location location) { return new Label_addr_expression(label, location); } // Class Conditional_expression. // Traversal. int Conditional_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->cond_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->then_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->else_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Return the type of the conditional expression. Type* Conditional_expression::do_type() { Type* result_type = Type::make_void_type(); if (Type::are_identical(this->then_->type(), this->else_->type(), Type::COMPARE_ERRORS | Type::COMPARE_TAGS, NULL)) result_type = this->then_->type(); else if (this->then_->is_nil_expression() || this->else_->is_nil_expression()) result_type = (!this->then_->is_nil_expression() ? this->then_->type() : this->else_->type()); return result_type; } // Determine type for a conditional expression. void Conditional_expression::do_determine_type(const Type_context* context) { this->cond_->determine_type_no_context(); this->then_->determine_type(context); this->else_->determine_type(context); } // Get the backend representation of a conditional expression. Bexpression* Conditional_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Btype* result_btype = this->type()->get_backend(gogo); Bexpression* cond = this->cond_->get_backend(context); Bexpression* then = this->then_->get_backend(context); Bexpression* belse = this->else_->get_backend(context); Bfunction* bfn = context->function()->func_value()->get_decl(); return gogo->backend()->conditional_expression(bfn, result_btype, cond, then, belse, this->location()); } // Dump ast representation of a conditional expression. void Conditional_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->cond_); ast_dump_context->ostream() << " ? "; ast_dump_context->dump_expression(this->then_); ast_dump_context->ostream() << " : "; ast_dump_context->dump_expression(this->else_); ast_dump_context->ostream() << ") "; } // Make a conditional expression. Expression* Expression::make_conditional(Expression* cond, Expression* then, Expression* else_expr, Location location) { return new Conditional_expression(cond, then, else_expr, location); } // Class Compound_expression. // Traversal. int Compound_expression::do_traverse(Traverse* traverse) { if (Expression::traverse(&this->init_, traverse) == TRAVERSE_EXIT || Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; return TRAVERSE_CONTINUE; } // Return the type of the compound expression. Type* Compound_expression::do_type() { return this->expr_->type(); } // Determine type for a compound expression. void Compound_expression::do_determine_type(const Type_context* context) { this->init_->determine_type_no_context(); this->expr_->determine_type(context); } // Get the backend representation of a compound expression. Bexpression* Compound_expression::do_get_backend(Translate_context* context) { Gogo* gogo = context->gogo(); Bexpression* binit = this->init_->get_backend(context); Bfunction* bfunction = context->function()->func_value()->get_decl(); Bstatement* init_stmt = gogo->backend()->expression_statement(bfunction, binit); Bexpression* bexpr = this->expr_->get_backend(context); return gogo->backend()->compound_expression(init_stmt, bexpr, this->location()); } // Dump ast representation of a conditional expression. void Compound_expression::do_dump_expression( Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "("; ast_dump_context->dump_expression(this->init_); ast_dump_context->ostream() << ","; ast_dump_context->dump_expression(this->expr_); ast_dump_context->ostream() << ") "; } // Make a compound expression. Expression* Expression::make_compound(Expression* init, Expression* expr, Location location) { return new Compound_expression(init, expr, location); } // Class Backend_expression. int Backend_expression::do_traverse(Traverse*) { return TRAVERSE_CONTINUE; } Expression* Backend_expression::do_copy() { return new Backend_expression(this->bexpr_, this->type_->copy_expressions(), this->location()); } void Backend_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const { ast_dump_context->ostream() << "backend_expression<"; ast_dump_context->dump_type(this->type_); ast_dump_context->ostream() << ">"; } Expression* Expression::make_backend(Bexpression* bexpr, Type* type, Location location) { return new Backend_expression(bexpr, type, location); } // Import an expression. This comes at the end in order to see the // various class definitions. Expression* Expression::import_expression(Import_expression* imp, Location loc) { Expression* expr = Expression::import_expression_without_suffix(imp, loc); while (true) { if (imp->match_c_string("(")) { imp->advance(1); Expression_list* args = new Expression_list(); bool is_varargs = false; while (!imp->match_c_string(")")) { Expression* arg = Expression::import_expression(imp, loc); if (arg->is_error_expression()) return arg; args->push_back(arg); if (imp->match_c_string(")")) break; else if (imp->match_c_string("...)")) { imp->advance(3); is_varargs = true; break; } imp->require_c_string(", "); } imp->require_c_string(")"); expr = Expression::make_call(expr, args, is_varargs, loc); expr->call_expression()->set_varargs_are_lowered(); } else if (imp->match_c_string("[")) { imp->advance(1); Expression* start = Expression::import_expression(imp, loc); Expression* end = NULL; Expression* cap = NULL; if (imp->match_c_string(":")) { imp->advance(1); int c = imp->peek_char(); if (c == ':' || c == ']') end = Expression::make_nil(loc); else end = Expression::import_expression(imp, loc); if (imp->match_c_string(":")) { imp->advance(1); cap = Expression::import_expression(imp, loc); } } imp->require_c_string("]"); expr = Expression::make_index(expr, start, end, cap, loc); } else break; } return expr; } // Import an expression without considering a suffix (function // arguments, index operations, etc.). Expression* Expression::import_expression_without_suffix(Import_expression* imp, Location loc) { int c = imp->peek_char(); if (c == '+' || c == '-' || c == '!' || c == '^' || c == '&' || c == '*') return Unary_expression::do_import(imp, loc); else if (c == '(') return Binary_expression::do_import(imp, loc); else if (imp->match_c_string("$true") || imp->match_c_string("$false") || (imp->version() < EXPORT_FORMAT_V3 && (imp->match_c_string("true") || imp->match_c_string("false")))) return Boolean_expression::do_import(imp, loc); else if (c == '"') return String_expression::do_import(imp, loc); else if (c == '-' || (c >= '0' && c <= '9')) { // This handles integers, floats and complex constants. return Integer_expression::do_import(imp, loc); } else if (imp->match_c_string("<-")) return Receive_expression::do_import(imp, loc); else if (imp->match_c_string("$nil") || (imp->version() < EXPORT_FORMAT_V3 && imp->match_c_string("nil"))) return Nil_expression::do_import(imp, loc); else if (imp->match_c_string("$convert") || (imp->version() < EXPORT_FORMAT_V3 && imp->match_c_string("convert"))) return Type_conversion_expression::do_import(imp, loc); Import_function_body* ifb = imp->ifb(); if (ifb == NULL) { go_error_at(imp->location(), "import error: expected expression"); return Expression::make_error(loc); } if (ifb->saw_error()) return Expression::make_error(loc); if (ifb->match_c_string("$t")) return Temporary_reference_expression::do_import(ifb, loc); return Expression::import_identifier(ifb, loc); } // Import an identifier in an expression. This is a reference to a // variable or function. Expression* Expression::import_identifier(Import_function_body* ifb, Location loc) { std::string id; Package* pkg; bool is_exported; if (!Import::read_qualified_identifier(ifb, &id, &pkg, &is_exported)) { if (!ifb->saw_error()) go_error_at(ifb->location(), "import error for %qs: bad qualified identifier at %lu", ifb->name().c_str(), static_cast(ifb->off())); ifb->set_saw_error(); return Expression::make_error(loc); } Named_object* no = NULL; if (pkg == NULL && is_exported) no = ifb->block()->bindings()->lookup(id); if (no == NULL) { const Package* ipkg = pkg; if (ipkg == NULL) ipkg = ifb->function()->package(); if (!is_exported) id = '.' + ipkg->pkgpath() + '.' + id; no = ipkg->bindings()->lookup(id); } if (no == NULL) no = ifb->gogo()->lookup_global(id.c_str()); if (no == NULL) { if (!ifb->saw_error()) go_error_at(ifb->location(), "import error for %qs: lookup of %qs failed", ifb->name().c_str(), id.c_str()); ifb->set_saw_error(); return Expression::make_error(loc); } if (no->is_variable() || no->is_result_variable()) return Expression::make_var_reference(no, loc); else if (no->is_function() || no->is_function_declaration()) return Expression::make_func_reference(no, NULL, loc); else { if (!ifb->saw_error()) go_error_at(ifb->location(), ("import error for %qs: " "unexpected type of identifier %qs (%d)"), ifb->name().c_str(), id.c_str(), no->classification()); ifb->set_saw_error(); return Expression::make_error(loc); } } // Class Expression_list. // Traverse the list. int Expression_list::traverse(Traverse* traverse) { for (Expression_list::iterator p = this->begin(); p != this->end(); ++p) { if (*p != NULL) { if (Expression::traverse(&*p, traverse) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } } return TRAVERSE_CONTINUE; } // Copy the list. Expression_list* Expression_list::copy() { Expression_list* ret = new Expression_list(); for (Expression_list::iterator p = this->begin(); p != this->end(); ++p) { if (*p == NULL) ret->push_back(NULL); else ret->push_back((*p)->copy()); } return ret; } // Return whether an expression list has an error expression. bool Expression_list::contains_error() const { for (Expression_list::const_iterator p = this->begin(); p != this->end(); ++p) if (*p != NULL && (*p)->is_error_expression()) return true; return false; } // Class Numeric_constant. // Destructor. Numeric_constant::~Numeric_constant() { this->clear(); } // Copy constructor. Numeric_constant::Numeric_constant(const Numeric_constant& a) : classification_(a.classification_), type_(a.type_) { switch (a.classification_) { case NC_INVALID: break; case NC_INT: case NC_RUNE: mpz_init_set(this->u_.int_val, a.u_.int_val); break; case NC_FLOAT: mpfr_init_set(this->u_.float_val, a.u_.float_val, MPFR_RNDN); break; case NC_COMPLEX: mpc_init2(this->u_.complex_val, mpc_precision); mpc_set(this->u_.complex_val, a.u_.complex_val, MPC_RNDNN); break; default: go_unreachable(); } } // Assignment operator. Numeric_constant& Numeric_constant::operator=(const Numeric_constant& a) { this->clear(); this->classification_ = a.classification_; this->type_ = a.type_; switch (a.classification_) { case NC_INVALID: break; case NC_INT: case NC_RUNE: mpz_init_set(this->u_.int_val, a.u_.int_val); break; case NC_FLOAT: mpfr_init_set(this->u_.float_val, a.u_.float_val, MPFR_RNDN); break; case NC_COMPLEX: mpc_init2(this->u_.complex_val, mpc_precision); mpc_set(this->u_.complex_val, a.u_.complex_val, MPC_RNDNN); break; default: go_unreachable(); } return *this; } // Check equality with another numeric constant. bool Numeric_constant::equals(const Numeric_constant& a) const { if (this->classification_ != a.classification_) return false; if (this->type_ != NULL && a.type_ != NULL && !Type::are_identical(this->type_, a.type_, Type::COMPARE_ALIASES, NULL)) return false; switch (a.classification_) { case NC_INVALID: break; case NC_INT: case NC_RUNE: return mpz_cmp(this->u_.int_val, a.u_.int_val) == 0; case NC_FLOAT: return mpfr_cmp(this->u_.float_val, a.u_.float_val) == 0; case NC_COMPLEX: return mpc_cmp(this->u_.complex_val, a.u_.complex_val) == 0; default: go_unreachable(); } return false; } // Clear the contents. void Numeric_constant::clear() { switch (this->classification_) { case NC_INVALID: break; case NC_INT: case NC_RUNE: mpz_clear(this->u_.int_val); break; case NC_FLOAT: mpfr_clear(this->u_.float_val); break; case NC_COMPLEX: mpc_clear(this->u_.complex_val); break; default: go_unreachable(); } this->classification_ = NC_INVALID; } // Set to an unsigned long value. void Numeric_constant::set_unsigned_long(Type* type, unsigned long val) { this->clear(); this->classification_ = NC_INT; this->type_ = type; mpz_init_set_ui(this->u_.int_val, val); } // Set to an integer value. void Numeric_constant::set_int(Type* type, const mpz_t val) { this->clear(); this->classification_ = NC_INT; this->type_ = type; mpz_init_set(this->u_.int_val, val); } // Set to a rune value. void Numeric_constant::set_rune(Type* type, const mpz_t val) { this->clear(); this->classification_ = NC_RUNE; this->type_ = type; mpz_init_set(this->u_.int_val, val); } // Set to a floating point value. void Numeric_constant::set_float(Type* type, const mpfr_t val) { this->clear(); this->classification_ = NC_FLOAT; this->type_ = type; // Numeric constants do not have negative zero values, so remove // them here. They also don't have infinity or NaN values, but we // should never see them here. int bits = 0; if (type != NULL && type->float_type() != NULL && !type->float_type()->is_abstract()) bits = type->float_type()->bits(); if (Numeric_constant::is_float_neg_zero(val, bits)) mpfr_init_set_ui(this->u_.float_val, 0, MPFR_RNDN); else mpfr_init_set(this->u_.float_val, val, MPFR_RNDN); } // Set to a complex value. void Numeric_constant::set_complex(Type* type, const mpc_t val) { this->clear(); this->classification_ = NC_COMPLEX; this->type_ = type; // Avoid negative zero as in set_float. int bits = 0; if (type != NULL && type->complex_type() != NULL && !type->complex_type()->is_abstract()) bits = type->complex_type()->bits() / 2; mpfr_t real; mpfr_init_set(real, mpc_realref(val), MPFR_RNDN); if (Numeric_constant::is_float_neg_zero(real, bits)) mpfr_set_ui(real, 0, MPFR_RNDN); mpfr_t imag; mpfr_init_set(imag, mpc_imagref(val), MPFR_RNDN); if (Numeric_constant::is_float_neg_zero(imag, bits)) mpfr_set_ui(imag, 0, MPFR_RNDN); mpc_init2(this->u_.complex_val, mpc_precision); mpc_set_fr_fr(this->u_.complex_val, real, imag, MPC_RNDNN); mpfr_clear(real); mpfr_clear(imag); } // Return whether VAL, at a precision of BITS, is a negative zero. // BITS may be zero in which case it is ignored. bool Numeric_constant::is_float_neg_zero(const mpfr_t val, int bits) { if (!mpfr_signbit(val)) return false; if (mpfr_zero_p(val)) return true; mpfr_exp_t min_exp; switch (bits) { case 0: return false; case 32: // In a denormalized float32 the exponent is -126, and there are // 24 bits of which at least the last must be 1, so the smallest // representable non-zero exponent is -126 - (24 - 1) == -149. min_exp = -149; break; case 64: // Minimum exponent is -1022, there are 53 bits. min_exp = -1074; break; default: go_unreachable(); } return mpfr_get_exp(val) < min_exp; } // Get an int value. void Numeric_constant::get_int(mpz_t* val) const { go_assert(this->is_int()); mpz_init_set(*val, this->u_.int_val); } // Get a rune value. void Numeric_constant::get_rune(mpz_t* val) const { go_assert(this->is_rune()); mpz_init_set(*val, this->u_.int_val); } // Get a floating point value. void Numeric_constant::get_float(mpfr_t* val) const { go_assert(this->is_float()); mpfr_init_set(*val, this->u_.float_val, MPFR_RNDN); } // Get a complex value. void Numeric_constant::get_complex(mpc_t* val) const { go_assert(this->is_complex()); mpc_init2(*val, mpc_precision); mpc_set(*val, this->u_.complex_val, MPC_RNDNN); } // Express value as unsigned long if possible. Numeric_constant::To_unsigned_long Numeric_constant::to_unsigned_long(unsigned long* val) const { switch (this->classification_) { case NC_INT: case NC_RUNE: return this->mpz_to_unsigned_long(this->u_.int_val, val); case NC_FLOAT: return this->mpfr_to_unsigned_long(this->u_.float_val, val); case NC_COMPLEX: if (!mpfr_zero_p(mpc_imagref(this->u_.complex_val))) return NC_UL_NOTINT; return this->mpfr_to_unsigned_long(mpc_realref(this->u_.complex_val), val); default: go_unreachable(); } } // Express integer value as unsigned long if possible. Numeric_constant::To_unsigned_long Numeric_constant::mpz_to_unsigned_long(const mpz_t ival, unsigned long *val) const { if (mpz_sgn(ival) < 0) return NC_UL_NEGATIVE; unsigned long ui = mpz_get_ui(ival); if (mpz_cmp_ui(ival, ui) != 0) return NC_UL_BIG; *val = ui; return NC_UL_VALID; } // Express floating point value as unsigned long if possible. Numeric_constant::To_unsigned_long Numeric_constant::mpfr_to_unsigned_long(const mpfr_t fval, unsigned long *val) const { if (!mpfr_integer_p(fval)) return NC_UL_NOTINT; mpz_t ival; mpz_init(ival); mpfr_get_z(ival, fval, MPFR_RNDN); To_unsigned_long ret = this->mpz_to_unsigned_long(ival, val); mpz_clear(ival); return ret; } // Express value as memory size if possible. bool Numeric_constant::to_memory_size(int64_t* val) const { switch (this->classification_) { case NC_INT: case NC_RUNE: return this->mpz_to_memory_size(this->u_.int_val, val); case NC_FLOAT: return this->mpfr_to_memory_size(this->u_.float_val, val); case NC_COMPLEX: if (!mpfr_zero_p(mpc_imagref(this->u_.complex_val))) return false; return this->mpfr_to_memory_size(mpc_realref(this->u_.complex_val), val); default: go_unreachable(); } } // Express integer as memory size if possible. bool Numeric_constant::mpz_to_memory_size(const mpz_t ival, int64_t* val) const { if (mpz_sgn(ival) < 0) return false; if (mpz_fits_slong_p(ival)) { *val = static_cast(mpz_get_si(ival)); return true; } // Test >= 64, not > 64, because an int64_t can hold 63 bits of a // positive value. if (mpz_sizeinbase(ival, 2) >= 64) return false; mpz_t q, r; mpz_init(q); mpz_init(r); mpz_tdiv_q_2exp(q, ival, 32); mpz_tdiv_r_2exp(r, ival, 32); go_assert(mpz_fits_ulong_p(q) && mpz_fits_ulong_p(r)); *val = ((static_cast(mpz_get_ui(q)) << 32) + static_cast(mpz_get_ui(r))); mpz_clear(r); mpz_clear(q); return true; } // Express floating point value as memory size if possible. bool Numeric_constant::mpfr_to_memory_size(const mpfr_t fval, int64_t* val) const { if (!mpfr_integer_p(fval)) return false; mpz_t ival; mpz_init(ival); mpfr_get_z(ival, fval, MPFR_RNDN); bool ret = this->mpz_to_memory_size(ival, val); mpz_clear(ival); return ret; } // Convert value to integer if possible. bool Numeric_constant::to_int(mpz_t* val) const { switch (this->classification_) { case NC_INT: case NC_RUNE: mpz_init_set(*val, this->u_.int_val); return true; case NC_FLOAT: if (!mpfr_integer_p(this->u_.float_val)) return false; mpz_init(*val); mpfr_get_z(*val, this->u_.float_val, MPFR_RNDN); return true; case NC_COMPLEX: if (!mpfr_zero_p(mpc_imagref(this->u_.complex_val)) || !mpfr_integer_p(mpc_realref(this->u_.complex_val))) return false; mpz_init(*val); mpfr_get_z(*val, mpc_realref(this->u_.complex_val), MPFR_RNDN); return true; default: go_unreachable(); } } // Convert value to floating point if possible. bool Numeric_constant::to_float(mpfr_t* val) const { switch (this->classification_) { case NC_INT: case NC_RUNE: mpfr_init_set_z(*val, this->u_.int_val, MPFR_RNDN); return true; case NC_FLOAT: mpfr_init_set(*val, this->u_.float_val, MPFR_RNDN); return true; case NC_COMPLEX: if (!mpfr_zero_p(mpc_imagref(this->u_.complex_val))) return false; mpfr_init_set(*val, mpc_realref(this->u_.complex_val), MPFR_RNDN); return true; default: go_unreachable(); } } // Convert value to complex. bool Numeric_constant::to_complex(mpc_t* val) const { mpc_init2(*val, mpc_precision); switch (this->classification_) { case NC_INT: case NC_RUNE: mpc_set_z(*val, this->u_.int_val, MPC_RNDNN); return true; case NC_FLOAT: mpc_set_fr(*val, this->u_.float_val, MPC_RNDNN); return true; case NC_COMPLEX: mpc_set(*val, this->u_.complex_val, MPC_RNDNN); return true; default: go_unreachable(); } } // Get the type. Type* Numeric_constant::type() const { if (this->type_ != NULL) return this->type_; switch (this->classification_) { case NC_INT: return Type::make_abstract_integer_type(); case NC_RUNE: return Type::make_abstract_character_type(); case NC_FLOAT: return Type::make_abstract_float_type(); case NC_COMPLEX: return Type::make_abstract_complex_type(); default: go_unreachable(); } } // If the constant can be expressed in TYPE, then set the type of the // constant to TYPE and return true. Otherwise return false, and, if // ISSUE_ERROR is true, report an appropriate error message. bool Numeric_constant::set_type(Type* type, bool issue_error, Location loc) { bool ret; if (type == NULL || type->is_error()) ret = true; else if (type->integer_type() != NULL) ret = this->check_int_type(type->integer_type(), issue_error, loc); else if (type->float_type() != NULL) ret = this->check_float_type(type->float_type(), issue_error, loc); else if (type->complex_type() != NULL) ret = this->check_complex_type(type->complex_type(), issue_error, loc); else { ret = false; if (issue_error) go_assert(saw_errors()); } if (ret) this->type_ = type; return ret; } // Check whether the constant can be expressed in an integer type. bool Numeric_constant::check_int_type(Integer_type* type, bool issue_error, Location location) { mpz_t val; switch (this->classification_) { case NC_INT: case NC_RUNE: mpz_init_set(val, this->u_.int_val); break; case NC_FLOAT: if (!mpfr_integer_p(this->u_.float_val)) { if (issue_error) { go_error_at(location, "floating-point constant truncated to integer"); this->set_invalid(); } return false; } mpz_init(val); mpfr_get_z(val, this->u_.float_val, MPFR_RNDN); break; case NC_COMPLEX: if (!mpfr_integer_p(mpc_realref(this->u_.complex_val)) || !mpfr_zero_p(mpc_imagref(this->u_.complex_val))) { if (issue_error) { go_error_at(location, "complex constant truncated to integer"); this->set_invalid(); } return false; } mpz_init(val); mpfr_get_z(val, mpc_realref(this->u_.complex_val), MPFR_RNDN); break; default: go_unreachable(); } bool ret; if (type->is_abstract()) ret = true; else { int bits = mpz_sizeinbase(val, 2); if (type->is_unsigned()) { // For an unsigned type we can only accept a nonnegative // number, and we must be able to represents at least BITS. ret = mpz_sgn(val) >= 0 && bits <= type->bits(); } else { // For a signed type we need an extra bit to indicate the // sign. We have to handle the most negative integer // specially. ret = (bits + 1 <= type->bits() || (bits <= type->bits() && mpz_sgn(val) < 0 && (mpz_scan1(val, 0) == static_cast(type->bits() - 1)) && mpz_scan0(val, type->bits()) == ULONG_MAX)); } } if (!ret && issue_error) { go_error_at(location, "integer constant overflow"); this->set_invalid(); } return ret; } // Check whether the constant can be expressed in a floating point // type. bool Numeric_constant::check_float_type(Float_type* type, bool issue_error, Location location) { mpfr_t val; switch (this->classification_) { case NC_INT: case NC_RUNE: mpfr_init_set_z(val, this->u_.int_val, MPFR_RNDN); break; case NC_FLOAT: mpfr_init_set(val, this->u_.float_val, MPFR_RNDN); break; case NC_COMPLEX: if (!mpfr_zero_p(mpc_imagref(this->u_.complex_val))) { if (issue_error) { this->set_invalid(); go_error_at(location, "complex constant truncated to floating-point"); } return false; } mpfr_init_set(val, mpc_realref(this->u_.complex_val), MPFR_RNDN); break; default: go_unreachable(); } bool ret; if (type->is_abstract()) ret = true; else if (mpfr_nan_p(val) || mpfr_inf_p(val) || mpfr_zero_p(val)) { // A NaN or Infinity always fits in the range of the type. ret = true; } else { mpfr_exp_t exp = mpfr_get_exp(val); mpfr_exp_t max_exp; switch (type->bits()) { case 32: max_exp = 128; break; case 64: max_exp = 1024; break; default: go_unreachable(); } ret = exp <= max_exp; if (ret) { // Round the constant to the desired type. mpfr_t t; mpfr_init(t); switch (type->bits()) { case 32: mpfr_set_prec(t, 24); break; case 64: mpfr_set_prec(t, 53); break; default: go_unreachable(); } mpfr_set(t, val, MPFR_RNDN); mpfr_set(val, t, MPFR_RNDN); mpfr_clear(t); this->set_float(type, val); } } mpfr_clear(val); if (!ret && issue_error) { go_error_at(location, "floating-point constant overflow"); this->set_invalid(); } return ret; } // Check whether the constant can be expressed in a complex type. bool Numeric_constant::check_complex_type(Complex_type* type, bool issue_error, Location location) { if (type->is_abstract()) return true; mpfr_exp_t max_exp; switch (type->bits()) { case 64: max_exp = 128; break; case 128: max_exp = 1024; break; default: go_unreachable(); } mpc_t val; mpc_init2(val, mpc_precision); switch (this->classification_) { case NC_INT: case NC_RUNE: mpc_set_z(val, this->u_.int_val, MPC_RNDNN); break; case NC_FLOAT: mpc_set_fr(val, this->u_.float_val, MPC_RNDNN); break; case NC_COMPLEX: mpc_set(val, this->u_.complex_val, MPC_RNDNN); break; default: go_unreachable(); } bool ret = true; if (!mpfr_nan_p(mpc_realref(val)) && !mpfr_inf_p(mpc_realref(val)) && !mpfr_zero_p(mpc_realref(val)) && mpfr_get_exp(mpc_realref(val)) > max_exp) { if (issue_error) { go_error_at(location, "complex real part overflow"); this->set_invalid(); } ret = false; } if (!mpfr_nan_p(mpc_imagref(val)) && !mpfr_inf_p(mpc_imagref(val)) && !mpfr_zero_p(mpc_imagref(val)) && mpfr_get_exp(mpc_imagref(val)) > max_exp) { if (issue_error) { go_error_at(location, "complex imaginary part overflow"); this->set_invalid(); } ret = false; } if (ret) { // Round the constant to the desired type. mpc_t t; switch (type->bits()) { case 64: mpc_init2(t, 24); break; case 128: mpc_init2(t, 53); break; default: go_unreachable(); } mpc_set(t, val, MPC_RNDNN); mpc_set(val, t, MPC_RNDNN); mpc_clear(t); this->set_complex(type, val); } mpc_clear(val); return ret; } // Return an Expression for this value. Expression* Numeric_constant::expression(Location loc) const { switch (this->classification_) { case NC_INT: return Expression::make_integer_z(&this->u_.int_val, this->type_, loc); case NC_RUNE: return Expression::make_character(&this->u_.int_val, this->type_, loc); case NC_FLOAT: return Expression::make_float(&this->u_.float_val, this->type_, loc); case NC_COMPLEX: return Expression::make_complex(&this->u_.complex_val, this->type_, loc); case NC_INVALID: go_assert(saw_errors()); return Expression::make_error(loc); default: go_unreachable(); } } // Calculate a hash code with a given seed. unsigned int Numeric_constant::hash(unsigned int seed) const { unsigned long val; const unsigned int PRIME = 97; long e = 0; double f = 1.0; mpfr_t m; switch (this->classification_) { case NC_INVALID: return PRIME; case NC_INT: case NC_RUNE: val = mpz_get_ui(this->u_.int_val); break; case NC_COMPLEX: mpfr_init(m); mpc_abs(m, this->u_.complex_val, MPFR_RNDN); val = mpfr_get_ui(m, MPFR_RNDN); mpfr_clear(m); break; case NC_FLOAT: f = mpfr_get_d_2exp(&e, this->u_.float_val, MPFR_RNDN) * 4294967295.0; val = static_cast(e + static_cast(f)); break; default: go_unreachable(); } return (static_cast(val) + seed) * PRIME; }