diff options
Diffstat (limited to 'gcc/go')
| -rw-r--r-- | gcc/go/gofrontend/go.cc | 9 | ||||
| -rw-r--r-- | gcc/go/gofrontend/statements.cc | 146 | ||||
| -rw-r--r-- | gcc/go/gofrontend/statements.h | 23 |
3 files changed, 136 insertions, 42 deletions
diff --git a/gcc/go/gofrontend/go.cc b/gcc/go/gofrontend/go.cc index 11692af..c0b3fef 100644 --- a/gcc/go/gofrontend/go.cc +++ b/gcc/go/gofrontend/go.cc @@ -44,7 +44,7 @@ go_create_gogo(int int_type_size, int pointer_size, const char *pkgpath, GO_EXTERN_C void go_parse_input_files(const char** filenames, unsigned int filename_count, - bool only_check_syntax, bool require_return_statement) + bool only_check_syntax, bool) { go_assert(filename_count > 0); @@ -84,6 +84,9 @@ go_parse_input_files(const char** filenames, unsigned int filename_count, // Finalize method lists and build stub methods for named types. ::gogo->finalize_methods(); + // Check that functions have a terminating statement. + ::gogo->check_return_statements(); + // Now that we have seen all the names, lower the parse tree into a // form which is easier to use. ::gogo->lower_parse_tree(); @@ -104,10 +107,6 @@ go_parse_input_files(const char** filenames, unsigned int filename_count, if (only_check_syntax) return; - // Check that functions have return statements. - if (require_return_statement) - ::gogo->check_return_statements(); - // Export global identifiers as appropriate. ::gogo->do_exports(); diff --git a/gcc/go/gofrontend/statements.cc b/gcc/go/gofrontend/statements.cc index 7870dad..c9c62ce 100644 --- a/gcc/go/gofrontend/statements.cc +++ b/gcc/go/gofrontend/statements.cc @@ -1707,8 +1707,8 @@ Expression_statement::do_check_types(Gogo*) this->expr_->discarding_value(); } -// An expression statement may fall through unless it is a call to a -// function which does not return. +// An expression statement is only a terminating statement if it is +// a call to panic. bool Expression_statement::do_may_fall_through() const @@ -1717,22 +1717,28 @@ Expression_statement::do_may_fall_through() const if (call != NULL) { const Expression* fn = call->fn(); - const Func_expression* fe = fn->func_expression(); - if (fe != NULL) + // panic is still an unknown named object. + const Unknown_expression* ue = fn->unknown_expression(); + if (ue != NULL) { - const Named_object* no = fe->named_object(); + Named_object* no = ue->named_object(); - 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 - fntype = NULL; - - // The builtin function panic does not return. - if (fntype != NULL && fntype->is_builtin() && no->name() == "panic") - return false; + if (no->is_unknown()) + no = no->unknown_value()->real_named_object(); + if (no != NULL) + { + 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 + fntype = NULL; + + // The builtin function panic does not return. + if (fntype != NULL && fntype->is_builtin() && no->name() == "panic") + return false; + } } } return true; @@ -3700,9 +3706,6 @@ class Constant_switch_statement : public Statement void do_check_types(Gogo*); - bool - do_may_fall_through() const; - Bstatement* do_get_backend(Translate_context*); @@ -3746,22 +3749,6 @@ Constant_switch_statement::do_check_types(Gogo*) this->set_is_error(); } -// Return whether this switch may fall through. - -bool -Constant_switch_statement::do_may_fall_through() const -{ - if (this->clauses_ == NULL) - return true; - - // If we have a break label, then some case needed it. That implies - // that the switch statement as a whole can fall through. - if (this->break_label_ != NULL) - return true; - - return this->clauses_->may_fall_through(); -} - // Convert to GENERIC. Bstatement* @@ -3911,6 +3898,22 @@ Switch_statement::do_dump_statement(Ast_dump_context* ast_dump_context) const ast_dump_context->ostream() << std::endl; } +// Return whether this switch may fall through. + +bool +Switch_statement::do_may_fall_through() const +{ + if (this->clauses_ == NULL) + return true; + + // If we have a break label, then some case needed it. That implies + // that the switch statement as a whole can fall through. + if (this->break_label_ != NULL) + return true; + + return this->clauses_->may_fall_through(); +} + // Make a switch statement. Switch_statement* @@ -4050,6 +4053,17 @@ Type_case_clauses::Type_case_clause::lower(Type* switch_val_type, } } +// Return true if this type clause may fall through to the statements +// following the switch. + +bool +Type_case_clauses::Type_case_clause::may_fall_through() const +{ + if (this->statements_ == NULL) + return true; + return this->statements_->may_fall_through(); +} + // Dump the AST representation for a type case clause void @@ -4148,6 +4162,25 @@ Type_case_clauses::lower(Type* switch_val_type, Block* b, NULL); } +// Return true if these clauses may fall through to the statements +// following the switch statement. + +bool +Type_case_clauses::may_fall_through() const +{ + bool found_default = false; + for (Type_clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (p->may_fall_through()) + return true; + if (p->is_default()) + found_default = true; + } + return !found_default; +} + // Dump the AST representation for case clauses (from a switch statement) void @@ -4237,6 +4270,22 @@ Type_switch_statement::do_lower(Gogo*, Named_object*, Block* enclosing, return Statement::make_block_statement(b, loc); } +// Return whether this switch may fall through. + +bool +Type_switch_statement::do_may_fall_through() const +{ + if (this->clauses_ == NULL) + return true; + + // If we have a break label, then some case needed it. That implies + // that the switch statement as a whole can fall through. + if (this->break_label_ != NULL) + return true; + + return this->clauses_->may_fall_through(); +} + // Return the break label for this type switch statement, creating it // if necessary. @@ -4954,6 +5003,19 @@ Select_statement::do_lower(Gogo* gogo, Named_object* function, return Statement::make_block_statement(b, loc); } +// Whether the select statement itself may fall through to the following +// statement. + +bool +Select_statement::do_may_fall_through() const +{ + // A select statement is terminating if no break statement + // refers to it and all of its clauses are terminating. + if (this->break_label_ != NULL) + return true; + return this->clauses_->may_fall_through(); +} + // Return the backend representation for a select statement. Bstatement* @@ -5114,6 +5176,20 @@ For_statement::set_break_continue_labels(Unnamed_label* break_label, this->continue_label_ = continue_label; } +// Whether the overall statement may fall through. + +bool +For_statement::do_may_fall_through() const +{ + // A for loop is terminating if it has no condition and + // no break statement. + if(this->cond_ != NULL) + return true; + if(this->break_label_ != NULL) + return true; + return false; +} + // Dump the AST representation for a for statement. void diff --git a/gcc/go/gofrontend/statements.h b/gcc/go/gofrontend/statements.h index c599571..ee5be87 100644 --- a/gcc/go/gofrontend/statements.h +++ b/gcc/go/gofrontend/statements.h @@ -894,8 +894,7 @@ class Select_statement : public Statement { this->clauses_->check_types(); } bool - do_may_fall_through() const - { return this->clauses_->may_fall_through(); } + do_may_fall_through() const; Bstatement* do_get_backend(Translate_context*); @@ -1086,6 +1085,9 @@ class For_statement : public Statement Statement* do_lower(Gogo*, Named_object*, Block*, Statement_inserter*); + bool + do_may_fall_through() const; + Bstatement* do_get_backend(Translate_context*) { go_unreachable(); } @@ -1399,6 +1401,9 @@ class Switch_statement : public Statement void do_dump_statement(Ast_dump_context*) const; + bool + do_may_fall_through() const; + private: // The value to switch on. This may be NULL. Expression* val_; @@ -1449,6 +1454,11 @@ class Type_case_clauses lower(Type*, Block*, Temporary_statement* descriptor_temp, Unnamed_label* break_label) const; + // Return true if these clauses may fall through to the statements + // following the switch statement. + bool + may_fall_through() const; + // Dump the AST representation to a dump context. void dump_clauses(Ast_dump_context*) const; @@ -1493,6 +1503,12 @@ class Type_case_clauses lower(Type*, Block*, Temporary_statement* descriptor_temp, Unnamed_label* break_label, Unnamed_label** stmts_label) const; + // Return true if this clause may fall through to execute the + // statements following the switch statement. This is not the + // same as whether this clause falls through to the next clause. + bool + may_fall_through() const; + // Dump the AST representation to a dump context. void dump_clause(Ast_dump_context*) const; @@ -1556,6 +1572,9 @@ class Type_switch_statement : public Statement void do_dump_statement(Ast_dump_context*) const; + bool + do_may_fall_through() const; + private: // The variable holding the value we are switching on. Named_object* var_; |