// gogo-tree.cc -- convert Go frontend Gogo IR to gcc trees. // 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 #ifndef ENABLE_BUILD_WITH_CXX extern "C" { #endif #include "toplev.h" #include "tree.h" #include "gimple.h" #include "tree-iterator.h" #include "cgraph.h" #include "langhooks.h" #include "convert.h" #include "output.h" #include "diagnostic.h" #ifndef ENABLE_BUILD_WITH_CXX } #endif #include "go-c.h" #include "types.h" #include "expressions.h" #include "statements.h" #include "runtime.h" #include "backend.h" #include "gogo.h" // Whether we have seen any errors. bool saw_errors() { return errorcount != 0 || sorrycount != 0; } // A helper function. static inline tree get_identifier_from_string(const std::string& str) { return get_identifier_with_length(str.data(), str.length()); } // Builtin functions. static std::map builtin_functions; // Define a builtin function. BCODE is the builtin function code // defined by builtins.def. NAME is the name of the builtin function. // LIBNAME is the name of the corresponding library function, and is // NULL if there isn't one. FNTYPE is the type of the function. // CONST_P is true if the function has the const attribute. static void define_builtin(built_in_function bcode, const char* name, const char* libname, tree fntype, bool const_p) { tree decl = add_builtin_function(name, fntype, bcode, BUILT_IN_NORMAL, libname, NULL_TREE); if (const_p) TREE_READONLY(decl) = 1; set_builtin_decl (bcode, decl, true); builtin_functions[name] = decl; if (libname != NULL) { decl = add_builtin_function(libname, fntype, bcode, BUILT_IN_NORMAL, NULL, NULL_TREE); if (const_p) TREE_READONLY(decl) = 1; builtin_functions[libname] = decl; } } // Create trees for implicit builtin functions. void Gogo::define_builtin_function_trees() { /* We need to define the fetch_and_add functions, since we use them for ++ and --. */ tree t = go_type_for_size(BITS_PER_UNIT, 1); tree p = build_pointer_type(build_qualified_type(t, TYPE_QUAL_VOLATILE)); define_builtin(BUILT_IN_SYNC_ADD_AND_FETCH_1, "__sync_fetch_and_add_1", NULL, build_function_type_list(t, p, t, NULL_TREE), false); t = go_type_for_size(BITS_PER_UNIT * 2, 1); p = build_pointer_type(build_qualified_type(t, TYPE_QUAL_VOLATILE)); define_builtin (BUILT_IN_SYNC_ADD_AND_FETCH_2, "__sync_fetch_and_add_2", NULL, build_function_type_list(t, p, t, NULL_TREE), false); t = go_type_for_size(BITS_PER_UNIT * 4, 1); p = build_pointer_type(build_qualified_type(t, TYPE_QUAL_VOLATILE)); define_builtin(BUILT_IN_SYNC_ADD_AND_FETCH_4, "__sync_fetch_and_add_4", NULL, build_function_type_list(t, p, t, NULL_TREE), false); t = go_type_for_size(BITS_PER_UNIT * 8, 1); p = build_pointer_type(build_qualified_type(t, TYPE_QUAL_VOLATILE)); define_builtin(BUILT_IN_SYNC_ADD_AND_FETCH_8, "__sync_fetch_and_add_8", NULL, build_function_type_list(t, p, t, NULL_TREE), false); // We use __builtin_expect for magic import functions. define_builtin(BUILT_IN_EXPECT, "__builtin_expect", NULL, build_function_type_list(long_integer_type_node, long_integer_type_node, long_integer_type_node, NULL_TREE), true); // We use __builtin_memmove for the predeclared copy function. define_builtin(BUILT_IN_MEMMOVE, "__builtin_memmove", "memmove", build_function_type_list(ptr_type_node, ptr_type_node, const_ptr_type_node, size_type_node, NULL_TREE), false); // We provide sqrt for the math library. define_builtin(BUILT_IN_SQRT, "__builtin_sqrt", "sqrt", build_function_type_list(double_type_node, double_type_node, NULL_TREE), true); define_builtin(BUILT_IN_SQRTL, "__builtin_sqrtl", "sqrtl", build_function_type_list(long_double_type_node, long_double_type_node, NULL_TREE), true); // We use __builtin_return_address in the thunk we build for // functions which call recover. define_builtin(BUILT_IN_RETURN_ADDRESS, "__builtin_return_address", NULL, build_function_type_list(ptr_type_node, unsigned_type_node, NULL_TREE), false); // The compiler uses __builtin_trap for some exception handling // cases. define_builtin(BUILT_IN_TRAP, "__builtin_trap", NULL, build_function_type(void_type_node, void_list_node), false); } // Get the name to use for the import control function. If there is a // global function or variable, then we know that that name must be // unique in the link, and we use it as the basis for our name. const std::string& Gogo::get_init_fn_name() { if (this->init_fn_name_.empty()) { go_assert(this->package_ != NULL); if (this->is_main_package()) { // Use a name which the runtime knows. this->init_fn_name_ = "__go_init_main"; } else { std::string s = this->unique_prefix(); s.append(1, '.'); s.append(this->package_name()); s.append("..import"); this->init_fn_name_ = s; } } return this->init_fn_name_; } // Add statements to INIT_STMT_LIST which run the initialization // functions for imported packages. This is only used for the "main" // package. void Gogo::init_imports(tree* init_stmt_list) { go_assert(this->is_main_package()); if (this->imported_init_fns_.empty()) return; tree fntype = build_function_type(void_type_node, void_list_node); // We must call them in increasing priority order. std::vector v; for (std::set::const_iterator p = this->imported_init_fns_.begin(); p != this->imported_init_fns_.end(); ++p) v.push_back(*p); std::sort(v.begin(), v.end()); for (std::vector::const_iterator p = v.begin(); p != v.end(); ++p) { std::string user_name = p->package_name() + ".init"; tree decl = build_decl(UNKNOWN_LOCATION, FUNCTION_DECL, get_identifier_from_string(user_name), fntype); const std::string& init_name(p->init_name()); SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(init_name)); TREE_PUBLIC(decl) = 1; DECL_EXTERNAL(decl) = 1; append_to_statement_list(build_call_expr(decl, 0), init_stmt_list); } } // Register global variables with the garbage collector. We need to // register all variables which can hold a pointer value. They become // roots during the mark phase. We build a struct that is easy to // hook into a list of roots. // struct __go_gc_root_list // { // struct __go_gc_root_list* __next; // struct __go_gc_root // { // void* __decl; // size_t __size; // } __roots[]; // }; // The last entry in the roots array has a NULL decl field. void Gogo::register_gc_vars(const std::vector& var_gc, tree* init_stmt_list) { if (var_gc.empty()) return; size_t count = var_gc.size(); tree root_type = Gogo::builtin_struct(NULL, "__go_gc_root", NULL_TREE, 2, "__next", ptr_type_node, "__size", sizetype); tree index_type = build_index_type(size_int(count)); tree array_type = build_array_type(root_type, index_type); tree root_list_type = make_node(RECORD_TYPE); root_list_type = Gogo::builtin_struct(NULL, "__go_gc_root_list", root_list_type, 2, "__next", build_pointer_type(root_list_type), "__roots", array_type); // Build an initialier for the __roots array. VEC(constructor_elt,gc)* roots_init = VEC_alloc(constructor_elt, gc, count + 1); size_t i = 0; for (std::vector::const_iterator p = var_gc.begin(); p != var_gc.end(); ++p, ++i) { VEC(constructor_elt,gc)* init = VEC_alloc(constructor_elt, gc, 2); constructor_elt* elt = VEC_quick_push(constructor_elt, init, NULL); tree field = TYPE_FIELDS(root_type); elt->index = field; Bvariable* bvar = (*p)->get_backend_variable(this, NULL); tree decl = var_to_tree(bvar); go_assert(TREE_CODE(decl) == VAR_DECL); elt->value = build_fold_addr_expr(decl); elt = VEC_quick_push(constructor_elt, init, NULL); field = DECL_CHAIN(field); elt->index = field; elt->value = DECL_SIZE_UNIT(decl); elt = VEC_quick_push(constructor_elt, roots_init, NULL); elt->index = size_int(i); elt->value = build_constructor(root_type, init); } // The list ends with a NULL entry. VEC(constructor_elt,gc)* init = VEC_alloc(constructor_elt, gc, 2); constructor_elt* elt = VEC_quick_push(constructor_elt, init, NULL); tree field = TYPE_FIELDS(root_type); elt->index = field; elt->value = fold_convert(TREE_TYPE(field), null_pointer_node); elt = VEC_quick_push(constructor_elt, init, NULL); field = DECL_CHAIN(field); elt->index = field; elt->value = size_zero_node; elt = VEC_quick_push(constructor_elt, roots_init, NULL); elt->index = size_int(i); elt->value = build_constructor(root_type, init); // Build a constructor for the struct. VEC(constructor_elt,gc*) root_list_init = VEC_alloc(constructor_elt, gc, 2); elt = VEC_quick_push(constructor_elt, root_list_init, NULL); field = TYPE_FIELDS(root_list_type); elt->index = field; elt->value = fold_convert(TREE_TYPE(field), null_pointer_node); elt = VEC_quick_push(constructor_elt, root_list_init, NULL); field = DECL_CHAIN(field); elt->index = field; elt->value = build_constructor(array_type, roots_init); // Build a decl to register. tree decl = build_decl(BUILTINS_LOCATION, VAR_DECL, create_tmp_var_name("gc"), root_list_type); DECL_EXTERNAL(decl) = 0; TREE_PUBLIC(decl) = 0; TREE_STATIC(decl) = 1; DECL_ARTIFICIAL(decl) = 1; DECL_INITIAL(decl) = build_constructor(root_list_type, root_list_init); rest_of_decl_compilation(decl, 1, 0); static tree register_gc_fndecl; tree call = Gogo::call_builtin(®ister_gc_fndecl, BUILTINS_LOCATION, "__go_register_gc_roots", 1, void_type_node, build_pointer_type(root_list_type), build_fold_addr_expr(decl)); if (call != error_mark_node) append_to_statement_list(call, init_stmt_list); } // Build the decl for the initialization function. tree Gogo::initialization_function_decl() { // The tedious details of building your own function. There doesn't // seem to be a helper function for this. std::string name = this->package_name() + ".init"; tree fndecl = build_decl(BUILTINS_LOCATION, FUNCTION_DECL, get_identifier_from_string(name), build_function_type(void_type_node, void_list_node)); const std::string& asm_name(this->get_init_fn_name()); SET_DECL_ASSEMBLER_NAME(fndecl, get_identifier_from_string(asm_name)); tree resdecl = build_decl(BUILTINS_LOCATION, RESULT_DECL, NULL_TREE, void_type_node); DECL_ARTIFICIAL(resdecl) = 1; DECL_CONTEXT(resdecl) = fndecl; DECL_RESULT(fndecl) = resdecl; TREE_STATIC(fndecl) = 1; TREE_USED(fndecl) = 1; DECL_ARTIFICIAL(fndecl) = 1; TREE_PUBLIC(fndecl) = 1; DECL_INITIAL(fndecl) = make_node(BLOCK); TREE_USED(DECL_INITIAL(fndecl)) = 1; return fndecl; } // Create the magic initialization function. INIT_STMT_LIST is the // code that it needs to run. void Gogo::write_initialization_function(tree fndecl, tree init_stmt_list) { // Make sure that we thought we needed an initialization function, // as otherwise we will not have reported it in the export data. go_assert(this->is_main_package() || this->need_init_fn_); if (fndecl == NULL_TREE) fndecl = this->initialization_function_decl(); DECL_SAVED_TREE(fndecl) = init_stmt_list; current_function_decl = fndecl; if (DECL_STRUCT_FUNCTION(fndecl) == NULL) push_struct_function(fndecl); else push_cfun(DECL_STRUCT_FUNCTION(fndecl)); cfun->function_end_locus = BUILTINS_LOCATION; gimplify_function_tree(fndecl); cgraph_add_new_function(fndecl, false); cgraph_mark_needed_node(cgraph_get_node(fndecl)); current_function_decl = NULL_TREE; pop_cfun(); } // Search for references to VAR in any statements or called functions. class Find_var : public Traverse { public: // A hash table we use to avoid looping. The index is the name of a // named object. We only look through objects defined in this // package. typedef Unordered_set(std::string) Seen_objects; Find_var(Named_object* var, Seen_objects* seen_objects) : Traverse(traverse_expressions), var_(var), seen_objects_(seen_objects), found_(false) { } // Whether the variable was found. bool found() const { return this->found_; } int expression(Expression**); private: // The variable we are looking for. Named_object* var_; // Names of objects we have already seen. Seen_objects* seen_objects_; // True if the variable was found. bool found_; }; // See if EXPR refers to VAR, looking through function calls and // variable initializations. int Find_var::expression(Expression** pexpr) { Expression* e = *pexpr; Var_expression* ve = e->var_expression(); if (ve != NULL) { Named_object* v = ve->named_object(); if (v == this->var_) { this->found_ = true; return TRAVERSE_EXIT; } if (v->is_variable() && v->package() == NULL) { Expression* init = v->var_value()->init(); if (init != NULL) { std::pair ins = this->seen_objects_->insert(v->name()); if (ins.second) { // This is the first time we have seen this name. if (Expression::traverse(&init, this) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } } } } // We traverse the code of any function we see. Note that this // means that we will traverse the code of a function whose address // is taken even if it is not called. Func_expression* fe = e->func_expression(); if (fe != NULL) { const Named_object* f = fe->named_object(); if (f->is_function() && f->package() == NULL) { std::pair ins = this->seen_objects_->insert(f->name()); if (ins.second) { // This is the first time we have seen this name. if (f->func_value()->block()->traverse(this) == TRAVERSE_EXIT) return TRAVERSE_EXIT; } } } return TRAVERSE_CONTINUE; } // Return true if EXPR refers to VAR. static bool expression_requires(Expression* expr, Block* preinit, Named_object* var) { Find_var::Seen_objects seen_objects; Find_var find_var(var, &seen_objects); if (expr != NULL) Expression::traverse(&expr, &find_var); if (preinit != NULL) preinit->traverse(&find_var); return find_var.found(); } // Sort variable initializations. If the initialization expression // for variable A refers directly or indirectly to the initialization // expression for variable B, then we must initialize B before A. class Var_init { public: Var_init() : var_(NULL), init_(NULL_TREE), waiting_(0) { } Var_init(Named_object* var, tree init) : var_(var), init_(init), waiting_(0) { } // Return the variable. Named_object* var() const { return this->var_; } // Return the initialization expression. tree init() const { return this->init_; } // Return the number of variables waiting for this one to be // initialized. size_t waiting() const { return this->waiting_; } // Increment the number waiting. void increment_waiting() { ++this->waiting_; } private: // The variable being initialized. Named_object* var_; // The initialization expression to run. tree init_; // The number of variables which are waiting for this one. size_t waiting_; }; typedef std::list Var_inits; // Sort the variable initializations. The rule we follow is that we // emit them in the order they appear in the array, except that if the // initialization expression for a variable V1 depends upon another // variable V2 then we initialize V1 after V2. static void sort_var_inits(Var_inits* var_inits) { Var_inits ready; while (!var_inits->empty()) { Var_inits::iterator p1 = var_inits->begin(); Named_object* var = p1->var(); Expression* init = var->var_value()->init(); Block* preinit = var->var_value()->preinit(); // Start walking through the list to see which variables VAR // needs to wait for. We can skip P1->WAITING variables--that // is the number we've already checked. Var_inits::iterator p2 = p1; ++p2; for (size_t i = p1->waiting(); i > 0; --i) ++p2; for (; p2 != var_inits->end(); ++p2) { if (expression_requires(init, preinit, p2->var())) { // Check for cycles. if (expression_requires(p2->var()->var_value()->init(), p2->var()->var_value()->preinit(), var)) { error_at(var->location(), ("initialization expressions for %qs and " "%qs depend upon each other"), var->message_name().c_str(), p2->var()->message_name().c_str()); inform(p2->var()->location(), "%qs defined here", p2->var()->message_name().c_str()); p2 = var_inits->end(); } else { // We can't emit P1 until P2 is emitted. Move P1. // Note that the WAITING loop always executes at // least once, which is what we want. p2->increment_waiting(); Var_inits::iterator p3 = p2; for (size_t i = p2->waiting(); i > 0; --i) ++p3; var_inits->splice(p3, *var_inits, p1); } break; } } if (p2 == var_inits->end()) { // VAR does not depends upon any other initialization expressions. // Check for a loop of VAR on itself. We only do this if // INIT is not NULL; when INIT is NULL, it means that // PREINIT sets VAR, which we will interpret as a loop. if (init != NULL && expression_requires(init, preinit, var)) error_at(var->location(), "initialization expression for %qs depends upon itself", var->message_name().c_str()); ready.splice(ready.end(), *var_inits, p1); } } // Now READY is the list in the desired initialization order. var_inits->swap(ready); } // Write out the global definitions. void Gogo::write_globals() { this->convert_named_types(); this->build_interface_method_tables(); Bindings* bindings = this->current_bindings(); size_t count = bindings->size_definitions(); tree* vec = new tree[count]; tree init_fndecl = NULL_TREE; tree init_stmt_list = NULL_TREE; if (this->is_main_package()) this->init_imports(&init_stmt_list); // A list of variable initializations. Var_inits var_inits; // A list of variables which need to be registered with the garbage // collector. std::vector var_gc; var_gc.reserve(count); tree var_init_stmt_list = NULL_TREE; size_t i = 0; for (Bindings::const_definitions_iterator p = bindings->begin_definitions(); p != bindings->end_definitions(); ++p, ++i) { Named_object* no = *p; go_assert(!no->is_type_declaration() && !no->is_function_declaration()); // There is nothing to do for a package. if (no->is_package()) { --i; --count; continue; } // There is nothing to do for an object which was imported from // a different package into the global scope. if (no->package() != NULL) { --i; --count; continue; } // There is nothing useful we can output for constants which // have ideal or non-integeral type. if (no->is_const()) { Type* type = no->const_value()->type(); if (type == NULL) type = no->const_value()->expr()->type(); if (type->is_abstract() || type->integer_type() == NULL) { --i; --count; continue; } } if (!no->is_variable()) { vec[i] = no->get_tree(this, NULL); if (vec[i] == error_mark_node) { go_assert(saw_errors()); --i; --count; continue; } } else { Bvariable* var = no->get_backend_variable(this, NULL); vec[i] = var_to_tree(var); if (vec[i] == error_mark_node) { go_assert(saw_errors()); --i; --count; continue; } // Check for a sink variable, which may be used to run an // initializer purely for its side effects. bool is_sink = no->name()[0] == '_' && no->name()[1] == '.'; tree var_init_tree = NULL_TREE; if (!no->var_value()->has_pre_init()) { tree init = no->var_value()->get_init_tree(this, NULL); if (init == error_mark_node) go_assert(saw_errors()); else if (init == NULL_TREE) ; else if (TREE_CONSTANT(init)) this->backend()->global_variable_set_init(var, tree_to_expr(init)); else if (is_sink) var_init_tree = init; else var_init_tree = fold_build2_loc(no->location(), MODIFY_EXPR, void_type_node, vec[i], init); } else { // We are going to create temporary variables which // means that we need an fndecl. if (init_fndecl == NULL_TREE) init_fndecl = this->initialization_function_decl(); current_function_decl = init_fndecl; if (DECL_STRUCT_FUNCTION(init_fndecl) == NULL) push_struct_function(init_fndecl); else push_cfun(DECL_STRUCT_FUNCTION(init_fndecl)); tree var_decl = is_sink ? NULL_TREE : vec[i]; var_init_tree = no->var_value()->get_init_block(this, NULL, var_decl); current_function_decl = NULL_TREE; pop_cfun(); } if (var_init_tree != NULL_TREE && var_init_tree != error_mark_node) { if (no->var_value()->init() == NULL && !no->var_value()->has_pre_init()) append_to_statement_list(var_init_tree, &var_init_stmt_list); else var_inits.push_back(Var_init(no, var_init_tree)); } if (!is_sink && no->var_value()->type()->has_pointer()) var_gc.push_back(no); } } // Register global variables with the garbage collector. this->register_gc_vars(var_gc, &init_stmt_list); // Simple variable initializations, after all variables are // registered. append_to_statement_list(var_init_stmt_list, &init_stmt_list); // Complex variable initializations, first sorting them into a // workable order. if (!var_inits.empty()) { sort_var_inits(&var_inits); for (Var_inits::const_iterator p = var_inits.begin(); p != var_inits.end(); ++p) append_to_statement_list(p->init(), &init_stmt_list); } // After all the variables are initialized, call the "init" // functions if there are any. for (std::vector::const_iterator p = this->init_functions_.begin(); p != this->init_functions_.end(); ++p) { tree decl = (*p)->get_tree(this, NULL); tree call = build_call_expr(decl, 0); append_to_statement_list(call, &init_stmt_list); } // Set up a magic function to do all the initialization actions. // This will be called if this package is imported. if (init_stmt_list != NULL_TREE || this->need_init_fn_ || this->is_main_package()) this->write_initialization_function(init_fndecl, init_stmt_list); // Pass everything back to the middle-end. wrapup_global_declarations(vec, count); cgraph_finalize_compilation_unit(); check_global_declarations(vec, count); emit_debug_global_declarations(vec, count); delete[] vec; } // Get a tree for the identifier for a named object. tree Named_object::get_id(Gogo* gogo) { go_assert(!this->is_variable() && !this->is_result_variable()); std::string decl_name; if (this->is_function_declaration() && !this->func_declaration_value()->asm_name().empty()) decl_name = this->func_declaration_value()->asm_name(); else if (this->is_type() && this->type_value()->location() == BUILTINS_LOCATION) { // We don't need the package name for builtin types. decl_name = Gogo::unpack_hidden_name(this->name_); } else { std::string package_name; if (this->package_ == NULL) package_name = gogo->package_name(); else package_name = this->package_->name(); decl_name = package_name + '.' + Gogo::unpack_hidden_name(this->name_); Function_type* fntype; if (this->is_function()) fntype = this->func_value()->type(); else if (this->is_function_declaration()) fntype = this->func_declaration_value()->type(); else fntype = NULL; if (fntype != NULL && fntype->is_method()) { decl_name.push_back('.'); decl_name.append(fntype->receiver()->type()->mangled_name(gogo)); } } if (this->is_type()) { const Named_object* in_function = this->type_value()->in_function(); if (in_function != NULL) decl_name += '$' + in_function->name(); } return get_identifier_from_string(decl_name); } // Get a tree for a named object. tree Named_object::get_tree(Gogo* gogo, Named_object* function) { if (this->tree_ != NULL_TREE) return this->tree_; tree name; if (this->classification_ == NAMED_OBJECT_TYPE) name = NULL_TREE; else name = this->get_id(gogo); tree decl; switch (this->classification_) { case NAMED_OBJECT_CONST: { Named_constant* named_constant = this->u_.const_value; Translate_context subcontext(gogo, function, NULL, NULL); tree expr_tree = named_constant->expr()->get_tree(&subcontext); if (expr_tree == error_mark_node) decl = error_mark_node; else { Type* type = named_constant->type(); if (type != NULL && !type->is_abstract()) { if (type->is_error()) expr_tree = error_mark_node; else { Btype* btype = type->get_backend(gogo); expr_tree = fold_convert(type_to_tree(btype), expr_tree); } } if (expr_tree == error_mark_node) decl = error_mark_node; else if (INTEGRAL_TYPE_P(TREE_TYPE(expr_tree))) { decl = build_decl(named_constant->location(), CONST_DECL, name, TREE_TYPE(expr_tree)); DECL_INITIAL(decl) = expr_tree; TREE_CONSTANT(decl) = 1; TREE_READONLY(decl) = 1; } else { // A CONST_DECL is only for an enum constant, so we // shouldn't use for non-integral types. Instead we // just return the constant itself, rather than a // decl. decl = expr_tree; } } } break; case NAMED_OBJECT_TYPE: { Named_type* named_type = this->u_.type_value; tree type_tree = type_to_tree(named_type->get_backend(gogo)); if (type_tree == error_mark_node) decl = error_mark_node; else { decl = TYPE_NAME(type_tree); go_assert(decl != NULL_TREE); // We need to produce a type descriptor for every named // type, and for a pointer to every named type, since // other files or packages might refer to them. We need // to do this even for hidden types, because they might // still be returned by some function. Simply calling the // type_descriptor method is enough to create the type // descriptor, even though we don't do anything with it. if (this->package_ == NULL) { named_type->type_descriptor_pointer(gogo, BUILTINS_LOCATION); Type* pn = Type::make_pointer_type(named_type); pn->type_descriptor_pointer(gogo, BUILTINS_LOCATION); } } } break; case NAMED_OBJECT_TYPE_DECLARATION: error("reference to undefined type %qs", this->message_name().c_str()); return error_mark_node; case NAMED_OBJECT_VAR: case NAMED_OBJECT_RESULT_VAR: case NAMED_OBJECT_SINK: go_unreachable(); case NAMED_OBJECT_FUNC: { Function* func = this->u_.func_value; decl = func->get_or_make_decl(gogo, this, name); if (decl != error_mark_node) { if (func->block() != NULL) { if (DECL_STRUCT_FUNCTION(decl) == NULL) push_struct_function(decl); else push_cfun(DECL_STRUCT_FUNCTION(decl)); cfun->function_end_locus = func->block()->end_location(); current_function_decl = decl; func->build_tree(gogo, this); gimplify_function_tree(decl); cgraph_finalize_function(decl, true); current_function_decl = NULL_TREE; pop_cfun(); } } } break; default: go_unreachable(); } if (TREE_TYPE(decl) == error_mark_node) decl = error_mark_node; tree ret = decl; this->tree_ = ret; if (ret != error_mark_node) go_preserve_from_gc(ret); return ret; } // Get the initial value of a variable as a tree. This does not // consider whether the variable is in the heap--it returns the // initial value as though it were always stored in the stack. tree Variable::get_init_tree(Gogo* gogo, Named_object* function) { go_assert(this->preinit_ == NULL); if (this->init_ == NULL) { go_assert(!this->is_parameter_); if (this->is_global_ || this->is_in_heap()) return NULL; Btype* btype = this->type_->get_backend(gogo); return expr_to_tree(gogo->backend()->zero_expression(btype)); } else { Translate_context context(gogo, function, NULL, NULL); tree rhs_tree = this->init_->get_tree(&context); return Expression::convert_for_assignment(&context, this->type(), this->init_->type(), rhs_tree, this->location()); } } // Get the initial value of a variable when a block is required. // VAR_DECL is the decl to set; it may be NULL for a sink variable. tree Variable::get_init_block(Gogo* gogo, Named_object* function, tree var_decl) { go_assert(this->preinit_ != NULL); // We want to add the variable assignment to the end of the preinit // block. The preinit block may have a TRY_FINALLY_EXPR and a // TRY_CATCH_EXPR; if it does, we want to add to the end of the // regular statements. Translate_context context(gogo, function, NULL, NULL); Bblock* bblock = this->preinit_->get_backend(&context); tree block_tree = block_to_tree(bblock); if (block_tree == error_mark_node) return error_mark_node; go_assert(TREE_CODE(block_tree) == BIND_EXPR); tree statements = BIND_EXPR_BODY(block_tree); while (statements != NULL_TREE && (TREE_CODE(statements) == TRY_FINALLY_EXPR || TREE_CODE(statements) == TRY_CATCH_EXPR)) statements = TREE_OPERAND(statements, 0); // It's possible to have pre-init statements without an initializer // if the pre-init statements set the variable. if (this->init_ != NULL) { tree rhs_tree = this->init_->get_tree(&context); if (rhs_tree == error_mark_node) return error_mark_node; if (var_decl == NULL_TREE) append_to_statement_list(rhs_tree, &statements); else { tree val = Expression::convert_for_assignment(&context, this->type(), this->init_->type(), rhs_tree, this->location()); if (val == error_mark_node) return error_mark_node; tree set = fold_build2_loc(this->location(), MODIFY_EXPR, void_type_node, var_decl, val); append_to_statement_list(set, &statements); } } return block_tree; } // Get a tree for a function decl. tree Function::get_or_make_decl(Gogo* gogo, Named_object* no, tree id) { if (this->fndecl_ == NULL_TREE) { tree functype = type_to_tree(this->type_->get_backend(gogo)); if (functype == error_mark_node) this->fndecl_ = error_mark_node; else { // The type of a function comes back as a pointer, but we // want the real function type for a function declaration. go_assert(POINTER_TYPE_P(functype)); functype = TREE_TYPE(functype); tree decl = build_decl(this->location(), FUNCTION_DECL, id, functype); this->fndecl_ = decl; if (no->package() != NULL) ; else if (this->enclosing_ != NULL || Gogo::is_thunk(no)) ; else if (Gogo::unpack_hidden_name(no->name()) == "init" && !this->type_->is_method()) ; else if (Gogo::unpack_hidden_name(no->name()) == "main" && gogo->is_main_package()) TREE_PUBLIC(decl) = 1; // Methods have to be public even if they are hidden because // they can be pulled into type descriptors when using // anonymous fields. else if (!Gogo::is_hidden_name(no->name()) || this->type_->is_method()) { TREE_PUBLIC(decl) = 1; std::string asm_name = gogo->unique_prefix(); asm_name.append(1, '.'); asm_name.append(IDENTIFIER_POINTER(id), IDENTIFIER_LENGTH(id)); SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(asm_name)); } // Why do we have to do this in the frontend? tree restype = TREE_TYPE(functype); tree resdecl = build_decl(this->location(), RESULT_DECL, NULL_TREE, restype); DECL_ARTIFICIAL(resdecl) = 1; DECL_IGNORED_P(resdecl) = 1; DECL_CONTEXT(resdecl) = decl; DECL_RESULT(decl) = resdecl; if (this->enclosing_ != NULL) DECL_STATIC_CHAIN(decl) = 1; // If a function calls the predeclared recover function, we // can't inline it, because recover behaves differently in a // function passed directly to defer. If this is a recover // thunk that we built to test whether a function can be // recovered, we can't inline it, because that will mess up // our return address comparison. if (this->calls_recover_ || this->is_recover_thunk_) DECL_UNINLINABLE(decl) = 1; // If this is a thunk created to call a function which calls // the predeclared recover function, we need to disable // stack splitting for the thunk. if (this->is_recover_thunk_) { tree attr = get_identifier("__no_split_stack__"); DECL_ATTRIBUTES(decl) = tree_cons(attr, NULL_TREE, NULL_TREE); } go_preserve_from_gc(decl); if (this->closure_var_ != NULL) { push_struct_function(decl); Bvariable* bvar = this->closure_var_->get_backend_variable(gogo, no); tree closure_decl = var_to_tree(bvar); if (closure_decl == error_mark_node) this->fndecl_ = error_mark_node; else { DECL_ARTIFICIAL(closure_decl) = 1; DECL_IGNORED_P(closure_decl) = 1; TREE_USED(closure_decl) = 1; DECL_ARG_TYPE(closure_decl) = TREE_TYPE(closure_decl); TREE_READONLY(closure_decl) = 1; DECL_STRUCT_FUNCTION(decl)->static_chain_decl = closure_decl; } pop_cfun(); } } } return this->fndecl_; } // Get a tree for a function declaration. tree Function_declaration::get_or_make_decl(Gogo* gogo, Named_object* no, tree id) { if (this->fndecl_ == NULL_TREE) { // Let Go code use an asm declaration to pick up a builtin // function. if (!this->asm_name_.empty()) { std::map::const_iterator p = builtin_functions.find(this->asm_name_); if (p != builtin_functions.end()) { this->fndecl_ = p->second; return this->fndecl_; } } tree functype = type_to_tree(this->fntype_->get_backend(gogo)); tree decl; if (functype == error_mark_node) decl = error_mark_node; else { // The type of a function comes back as a pointer, but we // want the real function type for a function declaration. go_assert(POINTER_TYPE_P(functype)); functype = TREE_TYPE(functype); decl = build_decl(this->location(), FUNCTION_DECL, id, functype); TREE_PUBLIC(decl) = 1; DECL_EXTERNAL(decl) = 1; if (this->asm_name_.empty()) { std::string asm_name = (no->package() == NULL ? gogo->unique_prefix() : no->package()->unique_prefix()); asm_name.append(1, '.'); asm_name.append(IDENTIFIER_POINTER(id), IDENTIFIER_LENGTH(id)); SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(asm_name)); } } this->fndecl_ = decl; go_preserve_from_gc(decl); } return this->fndecl_; } // We always pass the receiver to a method as a pointer. If the // receiver is actually declared as a non-pointer type, then we copy // the value into a local variable, so that it has the right type. In // this function we create the real PARM_DECL to use, and set // DEC_INITIAL of the var_decl to be the value passed in. tree Function::make_receiver_parm_decl(Gogo* gogo, Named_object* no, tree var_decl) { if (var_decl == error_mark_node) return error_mark_node; go_assert(TREE_CODE(var_decl) == VAR_DECL); tree val_type = TREE_TYPE(var_decl); bool is_in_heap = no->var_value()->is_in_heap(); if (is_in_heap) { go_assert(POINTER_TYPE_P(val_type)); val_type = TREE_TYPE(val_type); } source_location loc = DECL_SOURCE_LOCATION(var_decl); std::string name = IDENTIFIER_POINTER(DECL_NAME(var_decl)); name += ".pointer"; tree id = get_identifier_from_string(name); tree parm_decl = build_decl(loc, PARM_DECL, id, build_pointer_type(val_type)); DECL_CONTEXT(parm_decl) = current_function_decl; DECL_ARG_TYPE(parm_decl) = TREE_TYPE(parm_decl); go_assert(DECL_INITIAL(var_decl) == NULL_TREE); tree init = build_fold_indirect_ref_loc(loc, parm_decl); if (is_in_heap) { tree size = TYPE_SIZE_UNIT(val_type); tree space = gogo->allocate_memory(no->var_value()->type(), size, no->location()); space = save_expr(space); space = fold_convert(build_pointer_type(val_type), space); tree spaceref = build_fold_indirect_ref_loc(no->location(), space); TREE_THIS_NOTRAP(spaceref) = 1; tree set = fold_build2_loc(loc, MODIFY_EXPR, void_type_node, spaceref, init); init = fold_build2_loc(loc, COMPOUND_EXPR, TREE_TYPE(space), set, space); } DECL_INITIAL(var_decl) = init; return parm_decl; } // If we take the address of a parameter, then we need to copy it into // the heap. We will access it as a local variable via an // indirection. tree Function::copy_parm_to_heap(Gogo* gogo, Named_object* no, tree var_decl) { if (var_decl == error_mark_node) return error_mark_node; go_assert(TREE_CODE(var_decl) == VAR_DECL); source_location loc = DECL_SOURCE_LOCATION(var_decl); std::string name = IDENTIFIER_POINTER(DECL_NAME(var_decl)); name += ".param"; tree id = get_identifier_from_string(name); tree type = TREE_TYPE(var_decl); go_assert(POINTER_TYPE_P(type)); type = TREE_TYPE(type); tree parm_decl = build_decl(loc, PARM_DECL, id, type); DECL_CONTEXT(parm_decl) = current_function_decl; DECL_ARG_TYPE(parm_decl) = type; tree size = TYPE_SIZE_UNIT(type); tree space = gogo->allocate_memory(no->var_value()->type(), size, loc); space = save_expr(space); space = fold_convert(TREE_TYPE(var_decl), space); tree spaceref = build_fold_indirect_ref_loc(loc, space); TREE_THIS_NOTRAP(spaceref) = 1; tree init = build2(COMPOUND_EXPR, TREE_TYPE(space), build2(MODIFY_EXPR, void_type_node, spaceref, parm_decl), space); DECL_INITIAL(var_decl) = init; return parm_decl; } // Get a tree for function code. void Function::build_tree(Gogo* gogo, Named_object* named_function) { tree fndecl = this->fndecl_; go_assert(fndecl != NULL_TREE); tree params = NULL_TREE; tree* pp = ¶ms; tree declare_vars = NULL_TREE; for (Bindings::const_definitions_iterator p = this->block_->bindings()->begin_definitions(); p != this->block_->bindings()->end_definitions(); ++p) { if ((*p)->is_variable() && (*p)->var_value()->is_parameter()) { Bvariable* bvar = (*p)->get_backend_variable(gogo, named_function); *pp = var_to_tree(bvar); // We always pass the receiver to a method as a pointer. If // the receiver is declared as a non-pointer type, then we // copy the value into a local variable. if ((*p)->var_value()->is_receiver() && (*p)->var_value()->type()->points_to() == NULL) { tree parm_decl = this->make_receiver_parm_decl(gogo, *p, *pp); tree var = *pp; if (var != error_mark_node) { go_assert(TREE_CODE(var) == VAR_DECL); DECL_CHAIN(var) = declare_vars; declare_vars = var; } *pp = parm_decl; } else if ((*p)->var_value()->is_in_heap()) { // If we take the address of a parameter, then we need // to copy it into the heap. tree parm_decl = this->copy_parm_to_heap(gogo, *p, *pp); tree var = *pp; if (var != error_mark_node) { go_assert(TREE_CODE(var) == VAR_DECL); DECL_CHAIN(var) = declare_vars; declare_vars = var; } *pp = parm_decl; } if (*pp != error_mark_node) { go_assert(TREE_CODE(*pp) == PARM_DECL); pp = &DECL_CHAIN(*pp); } } else if ((*p)->is_result_variable()) { Bvariable* bvar = (*p)->get_backend_variable(gogo, named_function); tree var_decl = var_to_tree(bvar); Type* type = (*p)->result_var_value()->type(); tree init; if (!(*p)->result_var_value()->is_in_heap()) { Btype* btype = type->get_backend(gogo); init = expr_to_tree(gogo->backend()->zero_expression(btype)); } else { source_location loc = (*p)->location(); tree type_tree = type_to_tree(type->get_backend(gogo)); tree space = gogo->allocate_memory(type, TYPE_SIZE_UNIT(type_tree), loc); tree ptr_type_tree = build_pointer_type(type_tree); init = fold_convert_loc(loc, ptr_type_tree, space); } if (var_decl != error_mark_node) { go_assert(TREE_CODE(var_decl) == VAR_DECL); DECL_INITIAL(var_decl) = init; DECL_CHAIN(var_decl) = declare_vars; declare_vars = var_decl; } } } *pp = NULL_TREE; DECL_ARGUMENTS(fndecl) = params; if (this->block_ != NULL) { go_assert(DECL_INITIAL(fndecl) == NULL_TREE); // Declare variables if necessary. tree bind = NULL_TREE; tree defer_init = NULL_TREE; if (declare_vars != NULL_TREE || this->defer_stack_ != NULL) { tree block = make_node(BLOCK); BLOCK_SUPERCONTEXT(block) = fndecl; DECL_INITIAL(fndecl) = block; BLOCK_VARS(block) = declare_vars; TREE_USED(block) = 1; bind = build3(BIND_EXPR, void_type_node, BLOCK_VARS(block), NULL_TREE, block); TREE_SIDE_EFFECTS(bind) = 1; if (this->defer_stack_ != NULL) { Translate_context dcontext(gogo, named_function, this->block_, tree_to_block(bind)); Bstatement* bdi = this->defer_stack_->get_backend(&dcontext); defer_init = stat_to_tree(bdi); } } // Build the trees for all the statements in the function. Translate_context context(gogo, named_function, NULL, NULL); Bblock* bblock = this->block_->get_backend(&context); tree code = block_to_tree(bblock); tree init = NULL_TREE; tree except = NULL_TREE; tree fini = NULL_TREE; // Initialize variables if necessary. for (tree v = declare_vars; v != NULL_TREE; v = DECL_CHAIN(v)) { tree dv = build1(DECL_EXPR, void_type_node, v); SET_EXPR_LOCATION(dv, DECL_SOURCE_LOCATION(v)); append_to_statement_list(dv, &init); } // If we have a defer stack, initialize it at the start of a // function. if (defer_init != NULL_TREE && defer_init != error_mark_node) { SET_EXPR_LOCATION(defer_init, this->block_->start_location()); append_to_statement_list(defer_init, &init); // Clean up the defer stack when we leave the function. this->build_defer_wrapper(gogo, named_function, &except, &fini); } if (code != NULL_TREE && code != error_mark_node) { if (init != NULL_TREE) code = build2(COMPOUND_EXPR, void_type_node, init, code); if (except != NULL_TREE) code = build2(TRY_CATCH_EXPR, void_type_node, code, build2(CATCH_EXPR, void_type_node, NULL, except)); if (fini != NULL_TREE) code = build2(TRY_FINALLY_EXPR, void_type_node, code, fini); } // Stick the code into the block we built for the receiver, if // we built on. if (bind != NULL_TREE && code != NULL_TREE && code != error_mark_node) { BIND_EXPR_BODY(bind) = code; code = bind; } DECL_SAVED_TREE(fndecl) = code; } } // Build the wrappers around function code needed if the function has // any defer statements. This sets *EXCEPT to an exception handler // and *FINI to a finally handler. void Function::build_defer_wrapper(Gogo* gogo, Named_object* named_function, tree *except, tree *fini) { source_location end_loc = this->block_->end_location(); // Add an exception handler. This is used if a panic occurs. Its // purpose is to stop the stack unwinding if a deferred function // calls recover. There are more details in // libgo/runtime/go-unwind.c. tree stmt_list = NULL_TREE; Expression* call = Runtime::make_call(Runtime::CHECK_DEFER, end_loc, 1, this->defer_stack(end_loc)); Translate_context context(gogo, named_function, NULL, NULL); tree call_tree = call->get_tree(&context); if (call_tree != error_mark_node) append_to_statement_list(call_tree, &stmt_list); tree retval = this->return_value(gogo, named_function, end_loc, &stmt_list); tree set; if (retval == NULL_TREE) set = NULL_TREE; else set = fold_build2_loc(end_loc, MODIFY_EXPR, void_type_node, DECL_RESULT(this->fndecl_), retval); tree ret_stmt = fold_build1_loc(end_loc, RETURN_EXPR, void_type_node, set); append_to_statement_list(ret_stmt, &stmt_list); go_assert(*except == NULL_TREE); *except = stmt_list; // Add some finally code to run the defer functions. This is used // both in the normal case, when no panic occurs, and also if a // panic occurs to run any further defer functions. Of course, it // is possible for a defer function to call panic which should be // caught by another defer function. To handle that we use a loop. // finish: // try { __go_undefer(); } catch { __go_check_defer(); goto finish; } // if (return values are named) return named_vals; stmt_list = NULL; tree label = create_artificial_label(end_loc); tree define_label = fold_build1_loc(end_loc, LABEL_EXPR, void_type_node, label); append_to_statement_list(define_label, &stmt_list); call = Runtime::make_call(Runtime::UNDEFER, end_loc, 1, this->defer_stack(end_loc)); tree undefer = call->get_tree(&context); call = Runtime::make_call(Runtime::CHECK_DEFER, end_loc, 1, this->defer_stack(end_loc)); tree defer = call->get_tree(&context); if (undefer == error_mark_node || defer == error_mark_node) return; tree jump = fold_build1_loc(end_loc, GOTO_EXPR, void_type_node, label); tree catch_body = build2(COMPOUND_EXPR, void_type_node, defer, jump); catch_body = build2(CATCH_EXPR, void_type_node, NULL, catch_body); tree try_catch = build2(TRY_CATCH_EXPR, void_type_node, undefer, catch_body); append_to_statement_list(try_catch, &stmt_list); if (this->type_->results() != NULL && !this->type_->results()->empty() && !this->type_->results()->front().name().empty()) { // If the result variables are named, and we are returning from // this function rather than panicing through it, we need to // return them again, because they might have been changed by a // defer function. The runtime routines set the defer_stack // variable to true if we are returning from this function. retval = this->return_value(gogo, named_function, end_loc, &stmt_list); set = fold_build2_loc(end_loc, MODIFY_EXPR, void_type_node, DECL_RESULT(this->fndecl_), retval); ret_stmt = fold_build1_loc(end_loc, RETURN_EXPR, void_type_node, set); Expression* ref = Expression::make_temporary_reference(this->defer_stack_, end_loc); tree tref = ref->get_tree(&context); tree s = build3_loc(end_loc, COND_EXPR, void_type_node, tref, ret_stmt, NULL_TREE); append_to_statement_list(s, &stmt_list); } go_assert(*fini == NULL_TREE); *fini = stmt_list; } // Return the value to assign to DECL_RESULT(this->fndecl_). This may // also add statements to STMT_LIST, which need to be executed before // the assignment. This is used for a return statement with no // explicit values. tree Function::return_value(Gogo* gogo, Named_object* named_function, source_location location, tree* stmt_list) const { const Typed_identifier_list* results = this->type_->results(); if (results == NULL || results->empty()) return NULL_TREE; go_assert(this->results_ != NULL); if (this->results_->size() != results->size()) { go_assert(saw_errors()); return error_mark_node; } tree retval; if (results->size() == 1) { Bvariable* bvar = this->results_->front()->get_backend_variable(gogo, named_function); tree ret = var_to_tree(bvar); if (this->results_->front()->result_var_value()->is_in_heap()) ret = build_fold_indirect_ref_loc(location, ret); return ret; } else { tree rettype = TREE_TYPE(DECL_RESULT(this->fndecl_)); retval = create_tmp_var(rettype, "RESULT"); tree field = TYPE_FIELDS(rettype); int index = 0; for (Typed_identifier_list::const_iterator pr = results->begin(); pr != results->end(); ++pr, ++index, field = DECL_CHAIN(field)) { go_assert(field != NULL); Named_object* no = (*this->results_)[index]; Bvariable* bvar = no->get_backend_variable(gogo, named_function); tree val = var_to_tree(bvar); if (no->result_var_value()->is_in_heap()) val = build_fold_indirect_ref_loc(location, val); tree set = fold_build2_loc(location, MODIFY_EXPR, void_type_node, build3(COMPONENT_REF, TREE_TYPE(field), retval, field, NULL_TREE), val); append_to_statement_list(set, stmt_list); } return retval; } } // Return the integer type to use for a size. GO_EXTERN_C tree go_type_for_size(unsigned int bits, int unsignedp) { const char* name; switch (bits) { case 8: name = unsignedp ? "uint8" : "int8"; break; case 16: name = unsignedp ? "uint16" : "int16"; break; case 32: name = unsignedp ? "uint32" : "int32"; break; case 64: name = unsignedp ? "uint64" : "int64"; break; default: if (bits == POINTER_SIZE && unsignedp) name = "uintptr"; else return NULL_TREE; } Type* type = Type::lookup_integer_type(name); return type_to_tree(type->get_backend(go_get_gogo())); } // Return the type to use for a mode. GO_EXTERN_C tree go_type_for_mode(enum machine_mode mode, int unsignedp) { // FIXME: This static_cast should be in machmode.h. enum mode_class mc = static_cast(GET_MODE_CLASS(mode)); if (mc == MODE_INT) return go_type_for_size(GET_MODE_BITSIZE(mode), unsignedp); else if (mc == MODE_FLOAT) { Type* type; switch (GET_MODE_BITSIZE (mode)) { case 32: type = Type::lookup_float_type("float32"); break; case 64: type = Type::lookup_float_type("float64"); break; default: // We have to check for long double in order to support // i386 excess precision. if (mode == TYPE_MODE(long_double_type_node)) return long_double_type_node; return NULL_TREE; } return type_to_tree(type->get_backend(go_get_gogo())); } else if (mc == MODE_COMPLEX_FLOAT) { Type *type; switch (GET_MODE_BITSIZE (mode)) { case 64: type = Type::lookup_complex_type("complex64"); break; case 128: type = Type::lookup_complex_type("complex128"); break; default: // We have to check for long double in order to support // i386 excess precision. if (mode == TYPE_MODE(complex_long_double_type_node)) return complex_long_double_type_node; return NULL_TREE; } return type_to_tree(type->get_backend(go_get_gogo())); } else return NULL_TREE; } // Return a tree which allocates SIZE bytes which will holds value of // type TYPE. tree Gogo::allocate_memory(Type* type, tree size, source_location location) { // If the package imports unsafe, then it may play games with // pointers that look like integers. if (this->imported_unsafe_ || type->has_pointer()) { static tree new_fndecl; return Gogo::call_builtin(&new_fndecl, location, "__go_new", 1, ptr_type_node, sizetype, size); } else { static tree new_nopointers_fndecl; return Gogo::call_builtin(&new_nopointers_fndecl, location, "__go_new_nopointers", 1, ptr_type_node, sizetype, size); } } // Build a builtin struct with a list of fields. The name is // STRUCT_NAME. STRUCT_TYPE is NULL_TREE or an empty RECORD_TYPE // node; this exists so that the struct can have fields which point to // itself. If PTYPE is not NULL, store the result in *PTYPE. There // are NFIELDS fields. Each field is a name (a const char*) followed // by a type (a tree). tree Gogo::builtin_struct(tree* ptype, const char* struct_name, tree struct_type, int nfields, ...) { if (ptype != NULL && *ptype != NULL_TREE) return *ptype; va_list ap; va_start(ap, nfields); tree fields = NULL_TREE; for (int i = 0; i < nfields; ++i) { const char* field_name = va_arg(ap, const char*); tree type = va_arg(ap, tree); if (type == error_mark_node) { if (ptype != NULL) *ptype = error_mark_node; return error_mark_node; } tree field = build_decl(BUILTINS_LOCATION, FIELD_DECL, get_identifier(field_name), type); DECL_CHAIN(field) = fields; fields = field; } va_end(ap); if (struct_type == NULL_TREE) struct_type = make_node(RECORD_TYPE); finish_builtin_struct(struct_type, struct_name, fields, NULL_TREE); if (ptype != NULL) { go_preserve_from_gc(struct_type); *ptype = struct_type; } return struct_type; } // Return a type to use for pointer to const char for a string. tree Gogo::const_char_pointer_type_tree() { static tree type; if (type == NULL_TREE) { tree const_char_type = build_qualified_type(unsigned_char_type_node, TYPE_QUAL_CONST); type = build_pointer_type(const_char_type); go_preserve_from_gc(type); } return type; } // Return a tree for a string constant. tree Gogo::string_constant_tree(const std::string& val) { tree index_type = build_index_type(size_int(val.length())); tree const_char_type = build_qualified_type(unsigned_char_type_node, TYPE_QUAL_CONST); tree string_type = build_array_type(const_char_type, index_type); string_type = build_variant_type_copy(string_type); TYPE_STRING_FLAG(string_type) = 1; tree string_val = build_string(val.length(), val.data()); TREE_TYPE(string_val) = string_type; return string_val; } // Return a tree for a Go string constant. tree Gogo::go_string_constant_tree(const std::string& val) { tree string_type = type_to_tree(Type::make_string_type()->get_backend(this)); VEC(constructor_elt, gc)* init = VEC_alloc(constructor_elt, gc, 2); constructor_elt* elt = VEC_quick_push(constructor_elt, init, NULL); tree field = TYPE_FIELDS(string_type); go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__data") == 0); elt->index = field; tree str = Gogo::string_constant_tree(val); elt->value = fold_convert(TREE_TYPE(field), build_fold_addr_expr(str)); elt = VEC_quick_push(constructor_elt, init, NULL); field = DECL_CHAIN(field); go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__length") == 0); elt->index = field; elt->value = build_int_cst_type(TREE_TYPE(field), val.length()); tree constructor = build_constructor(string_type, init); TREE_READONLY(constructor) = 1; TREE_CONSTANT(constructor) = 1; return constructor; } // Return a tree for a pointer to a Go string constant. This is only // used for type descriptors, so we return a pointer to a constant // decl. tree Gogo::ptr_go_string_constant_tree(const std::string& val) { tree pval = this->go_string_constant_tree(val); tree decl = build_decl(UNKNOWN_LOCATION, VAR_DECL, create_tmp_var_name("SP"), TREE_TYPE(pval)); DECL_EXTERNAL(decl) = 0; TREE_PUBLIC(decl) = 0; TREE_USED(decl) = 1; TREE_READONLY(decl) = 1; TREE_CONSTANT(decl) = 1; TREE_STATIC(decl) = 1; DECL_ARTIFICIAL(decl) = 1; DECL_INITIAL(decl) = pval; rest_of_decl_compilation(decl, 1, 0); return build_fold_addr_expr(decl); } // Build a constructor for a slice. SLICE_TYPE_TREE is the type of // the slice. VALUES is the value pointer and COUNT is the number of // entries. If CAPACITY is not NULL, it is the capacity; otherwise // the capacity and the count are the same. tree Gogo::slice_constructor(tree slice_type_tree, tree values, tree count, tree capacity) { go_assert(TREE_CODE(slice_type_tree) == RECORD_TYPE); VEC(constructor_elt,gc)* init = VEC_alloc(constructor_elt, gc, 3); tree field = TYPE_FIELDS(slice_type_tree); go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__values") == 0); constructor_elt* elt = VEC_quick_push(constructor_elt, init, NULL); elt->index = field; go_assert(TYPE_MAIN_VARIANT(TREE_TYPE(field)) == TYPE_MAIN_VARIANT(TREE_TYPE(values))); elt->value = values; count = fold_convert(sizetype, count); if (capacity == NULL_TREE) { count = save_expr(count); capacity = count; } field = DECL_CHAIN(field); go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__count") == 0); elt = VEC_quick_push(constructor_elt, init, NULL); elt->index = field; elt->value = fold_convert(TREE_TYPE(field), count); field = DECL_CHAIN(field); go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__capacity") == 0); elt = VEC_quick_push(constructor_elt, init, NULL); elt->index = field; elt->value = fold_convert(TREE_TYPE(field), capacity); return build_constructor(slice_type_tree, init); } // Build an interface method table for a type: a list of function // pointers, one for each interface method. This is used for // interfaces. tree Gogo::interface_method_table_for_type(const Interface_type* interface, Named_type* type, bool is_pointer) { const Typed_identifier_list* interface_methods = interface->methods(); go_assert(!interface_methods->empty()); std::string mangled_name = ((is_pointer ? "__go_pimt__" : "__go_imt_") + interface->mangled_name(this) + "__" + type->mangled_name(this)); tree id = get_identifier_from_string(mangled_name); // See whether this interface has any hidden methods. bool has_hidden_methods = false; for (Typed_identifier_list::const_iterator p = interface_methods->begin(); p != interface_methods->end(); ++p) { if (Gogo::is_hidden_name(p->name())) { has_hidden_methods = true; break; } } // We already know that the named type is convertible to the // interface. If the interface has hidden methods, and the named // type is defined in a different package, then the interface // conversion table will be defined by that other package. if (has_hidden_methods && type->named_object()->package() != NULL) { tree array_type = build_array_type(const_ptr_type_node, NULL); tree decl = build_decl(BUILTINS_LOCATION, VAR_DECL, id, array_type); TREE_READONLY(decl) = 1; TREE_CONSTANT(decl) = 1; TREE_PUBLIC(decl) = 1; DECL_EXTERNAL(decl) = 1; go_preserve_from_gc(decl); return decl; } size_t count = interface_methods->size(); VEC(constructor_elt, gc)* pointers = VEC_alloc(constructor_elt, gc, count + 1); // The first element is the type descriptor. constructor_elt* elt = VEC_quick_push(constructor_elt, pointers, NULL); elt->index = size_zero_node; Type* td_type; if (!is_pointer) td_type = type; else td_type = Type::make_pointer_type(type); tree tdp = td_type->type_descriptor_pointer(this, BUILTINS_LOCATION); elt->value = fold_convert(const_ptr_type_node, tdp); size_t i = 1; for (Typed_identifier_list::const_iterator p = interface_methods->begin(); p != interface_methods->end(); ++p, ++i) { bool is_ambiguous; Method* m = type->method_function(p->name(), &is_ambiguous); go_assert(m != NULL); Named_object* no = m->named_object(); tree fnid = no->get_id(this); tree fndecl; if (no->is_function()) fndecl = no->func_value()->get_or_make_decl(this, no, fnid); else if (no->is_function_declaration()) fndecl = no->func_declaration_value()->get_or_make_decl(this, no, fnid); else go_unreachable(); fndecl = build_fold_addr_expr(fndecl); elt = VEC_quick_push(constructor_elt, pointers, NULL); elt->index = size_int(i); elt->value = fold_convert(const_ptr_type_node, fndecl); } go_assert(i == count + 1); tree array_type = build_array_type(const_ptr_type_node, build_index_type(size_int(count))); tree constructor = build_constructor(array_type, pointers); tree decl = build_decl(BUILTINS_LOCATION, VAR_DECL, id, array_type); TREE_STATIC(decl) = 1; TREE_USED(decl) = 1; TREE_READONLY(decl) = 1; TREE_CONSTANT(decl) = 1; DECL_INITIAL(decl) = constructor; // If the interface type has hidden methods, then this is the only // definition of the table. Otherwise it is a comdat table which // may be defined in multiple packages. if (has_hidden_methods) TREE_PUBLIC(decl) = 1; else { make_decl_one_only(decl, DECL_ASSEMBLER_NAME(decl)); resolve_unique_section(decl, 1, 0); } rest_of_decl_compilation(decl, 1, 0); go_preserve_from_gc(decl); return decl; } // Mark a function as a builtin library function. void Gogo::mark_fndecl_as_builtin_library(tree fndecl) { DECL_EXTERNAL(fndecl) = 1; TREE_PUBLIC(fndecl) = 1; DECL_ARTIFICIAL(fndecl) = 1; TREE_NOTHROW(fndecl) = 1; DECL_VISIBILITY(fndecl) = VISIBILITY_DEFAULT; DECL_VISIBILITY_SPECIFIED(fndecl) = 1; } // Build a call to a builtin function. tree Gogo::call_builtin(tree* pdecl, source_location location, const char* name, int nargs, tree rettype, ...) { if (rettype == error_mark_node) return error_mark_node; tree* types = new tree[nargs]; tree* args = new tree[nargs]; va_list ap; va_start(ap, rettype); for (int i = 0; i < nargs; ++i) { types[i] = va_arg(ap, tree); args[i] = va_arg(ap, tree); if (types[i] == error_mark_node || args[i] == error_mark_node) { delete[] types; delete[] args; return error_mark_node; } } va_end(ap); if (*pdecl == NULL_TREE) { tree fnid = get_identifier(name); tree argtypes = NULL_TREE; tree* pp = &argtypes; for (int i = 0; i < nargs; ++i) { *pp = tree_cons(NULL_TREE, types[i], NULL_TREE); pp = &TREE_CHAIN(*pp); } *pp = void_list_node; tree fntype = build_function_type(rettype, argtypes); *pdecl = build_decl(BUILTINS_LOCATION, FUNCTION_DECL, fnid, fntype); Gogo::mark_fndecl_as_builtin_library(*pdecl); go_preserve_from_gc(*pdecl); } tree fnptr = build_fold_addr_expr(*pdecl); if (CAN_HAVE_LOCATION_P(fnptr)) SET_EXPR_LOCATION(fnptr, location); tree ret = build_call_array(rettype, fnptr, nargs, args); SET_EXPR_LOCATION(ret, location); delete[] types; delete[] args; return ret; } // Build a call to the runtime error function. tree Gogo::runtime_error(int code, source_location location) { static tree runtime_error_fndecl; tree ret = Gogo::call_builtin(&runtime_error_fndecl, location, "__go_runtime_error", 1, void_type_node, integer_type_node, build_int_cst(integer_type_node, code)); if (ret == error_mark_node) return error_mark_node; // The runtime error function panics and does not return. TREE_NOTHROW(runtime_error_fndecl) = 0; TREE_THIS_VOLATILE(runtime_error_fndecl) = 1; return ret; } // Return a tree for receiving a value of type TYPE_TREE on CHANNEL. // This does a blocking receive and returns the value read from the // channel. If FOR_SELECT is true, this is being done because it was // chosen in a select statement. tree Gogo::receive_from_channel(tree type_tree, tree channel, bool for_select, source_location location) { if (type_tree == error_mark_node || channel == error_mark_node) return error_mark_node; if (int_size_in_bytes(type_tree) <= 8 && !AGGREGATE_TYPE_P(type_tree) && !FLOAT_TYPE_P(type_tree)) { static tree receive_small_fndecl; tree call = Gogo::call_builtin(&receive_small_fndecl, location, "__go_receive_small", 2, uint64_type_node, ptr_type_node, channel, boolean_type_node, (for_select ? boolean_true_node : boolean_false_node)); if (call == error_mark_node) return error_mark_node; // This can panic if there are too many operations on a closed // channel. TREE_NOTHROW(receive_small_fndecl) = 0; int bitsize = GET_MODE_BITSIZE(TYPE_MODE(type_tree)); tree int_type_tree = go_type_for_size(bitsize, 1); return fold_convert_loc(location, type_tree, fold_convert_loc(location, int_type_tree, call)); } else { tree tmp = create_tmp_var(type_tree, get_name(type_tree)); DECL_IGNORED_P(tmp) = 0; TREE_ADDRESSABLE(tmp) = 1; tree make_tmp = build1(DECL_EXPR, void_type_node, tmp); SET_EXPR_LOCATION(make_tmp, location); tree tmpaddr = build_fold_addr_expr(tmp); tmpaddr = fold_convert(ptr_type_node, tmpaddr); static tree receive_big_fndecl; tree call = Gogo::call_builtin(&receive_big_fndecl, location, "__go_receive_big", 3, boolean_type_node, ptr_type_node, channel, ptr_type_node, tmpaddr, boolean_type_node, (for_select ? boolean_true_node : boolean_false_node)); if (call == error_mark_node) return error_mark_node; // This can panic if there are too many operations on a closed // channel. TREE_NOTHROW(receive_big_fndecl) = 0; return build2(COMPOUND_EXPR, type_tree, make_tmp, build2(COMPOUND_EXPR, type_tree, call, tmp)); } } // Return the type of a function trampoline. This is like // get_trampoline_type in tree-nested.c. tree Gogo::trampoline_type_tree() { static tree type_tree; if (type_tree == NULL_TREE) { unsigned int size; unsigned int align; go_trampoline_info(&size, &align); tree t = build_index_type(build_int_cst(integer_type_node, size - 1)); t = build_array_type(char_type_node, t); type_tree = Gogo::builtin_struct(NULL, "__go_trampoline", NULL_TREE, 1, "__data", t); t = TYPE_FIELDS(type_tree); DECL_ALIGN(t) = align; DECL_USER_ALIGN(t) = 1; go_preserve_from_gc(type_tree); } return type_tree; } // Make a trampoline which calls FNADDR passing CLOSURE. tree Gogo::make_trampoline(tree fnaddr, tree closure, source_location location) { tree trampoline_type = Gogo::trampoline_type_tree(); tree trampoline_size = TYPE_SIZE_UNIT(trampoline_type); closure = save_expr(closure); // We allocate the trampoline using a special function which will // mark it as executable. static tree trampoline_fndecl; tree x = Gogo::call_builtin(&trampoline_fndecl, location, "__go_allocate_trampoline", 2, ptr_type_node, size_type_node, trampoline_size, ptr_type_node, fold_convert_loc(location, ptr_type_node, closure)); if (x == error_mark_node) return error_mark_node; x = save_expr(x); // Initialize the trampoline. tree ini = build_call_expr(builtin_decl_implicit(BUILT_IN_INIT_TRAMPOLINE), 3, x, fnaddr, closure); // On some targets the trampoline address needs to be adjusted. For // example, when compiling in Thumb mode on the ARM, the address // needs to have the low bit set. x = build_call_expr(builtin_decl_explicit(BUILT_IN_ADJUST_TRAMPOLINE), 1, x); x = fold_convert(TREE_TYPE(fnaddr), x); return build2(COMPOUND_EXPR, TREE_TYPE(x), ini, x); }