diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/go/gofrontend/MERGE | 2 | ||||
| -rw-r--r-- | gcc/go/gofrontend/go.cc | 6 | ||||
| -rw-r--r-- | gcc/go/gofrontend/gogo.cc | 425 |
3 files changed, 225 insertions, 208 deletions
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 726bf3a..abd5592 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -38850073f25f9de4f3daa33d799def3a33c942ab +39d4d755db7d71b5e770ca435a8b1d1f08f53185 The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/gcc/go/gofrontend/go.cc b/gcc/go/gofrontend/go.cc index 5f08eea..d444e4a 100644 --- a/gcc/go/gofrontend/go.cc +++ b/gcc/go/gofrontend/go.cc @@ -143,12 +143,12 @@ go_parse_input_files(const char** filenames, unsigned int filename_count, // Export global identifiers as appropriate. ::gogo->do_exports(); - // Turn short-cut operators (&&, ||) into explicit if statements. - ::gogo->remove_shortcuts(); - // Use temporary variables to force order of evaluation. ::gogo->order_evaluations(); + // Turn short-cut operators (&&, ||) into explicit if statements. + ::gogo->remove_shortcuts(); + // Convert named types to backend representation. ::gogo->convert_named_types(); diff --git a/gcc/go/gofrontend/gogo.cc b/gcc/go/gofrontend/gogo.cc index c89785c..c16b40e 100644 --- a/gcc/go/gofrontend/gogo.cc +++ b/gcc/go/gofrontend/gogo.cc @@ -3432,210 +3432,6 @@ Gogo::check_types_in_block(Block* block) block->traverse(&traverse); } -// A traversal class used to find a single shortcut operator within an -// expression. - -class Find_shortcut : public Traverse -{ - public: - Find_shortcut() - : Traverse(traverse_blocks - | traverse_statements - | traverse_expressions), - found_(NULL) - { } - - // A pointer to the expression which was found, or NULL if none was - // found. - Expression** - found() const - { return this->found_; } - - protected: - int - block(Block*) - { return TRAVERSE_SKIP_COMPONENTS; } - - int - statement(Block*, size_t*, Statement*) - { return TRAVERSE_SKIP_COMPONENTS; } - - int - expression(Expression**); - - private: - Expression** found_; -}; - -// Find a shortcut expression. - -int -Find_shortcut::expression(Expression** pexpr) -{ - Expression* expr = *pexpr; - Binary_expression* be = expr->binary_expression(); - if (be == NULL) - return TRAVERSE_CONTINUE; - Operator op = be->op(); - if (op != OPERATOR_OROR && op != OPERATOR_ANDAND) - return TRAVERSE_CONTINUE; - go_assert(this->found_ == NULL); - this->found_ = pexpr; - return TRAVERSE_EXIT; -} - -// A traversal class used to turn shortcut operators into explicit if -// statements. - -class Shortcuts : public Traverse -{ - public: - Shortcuts(Gogo* gogo) - : Traverse(traverse_variables - | traverse_statements), - gogo_(gogo) - { } - - protected: - int - variable(Named_object*); - - int - statement(Block*, size_t*, Statement*); - - private: - // Convert a shortcut operator. - Statement* - convert_shortcut(Block* enclosing, Expression** pshortcut); - - // The IR. - Gogo* gogo_; -}; - -// Remove shortcut operators in a single statement. - -int -Shortcuts::statement(Block* block, size_t* pindex, Statement* s) -{ - // FIXME: This approach doesn't work for switch statements, because - // we add the new statements before the whole switch when we need to - // instead add them just before the switch expression. The right - // fix is probably to lower switch statements with nonconstant cases - // to a series of conditionals. - if (s->switch_statement() != NULL) - return TRAVERSE_CONTINUE; - - while (true) - { - Find_shortcut find_shortcut; - - // If S is a variable declaration, then ordinary traversal won't - // do anything. We want to explicitly traverse the - // initialization expression if there is one. - Variable_declaration_statement* vds = s->variable_declaration_statement(); - Expression* init = NULL; - if (vds == NULL) - s->traverse_contents(&find_shortcut); - else - { - init = vds->var()->var_value()->init(); - if (init == NULL) - return TRAVERSE_CONTINUE; - init->traverse(&init, &find_shortcut); - } - Expression** pshortcut = find_shortcut.found(); - if (pshortcut == NULL) - return TRAVERSE_CONTINUE; - - Statement* snew = this->convert_shortcut(block, pshortcut); - block->insert_statement_before(*pindex, snew); - ++*pindex; - - if (pshortcut == &init) - vds->var()->var_value()->set_init(init); - } -} - -// Remove shortcut operators in the initializer of a global variable. - -int -Shortcuts::variable(Named_object* no) -{ - if (no->is_result_variable()) - return TRAVERSE_CONTINUE; - Variable* var = no->var_value(); - Expression* init = var->init(); - if (!var->is_global() || init == NULL) - return TRAVERSE_CONTINUE; - - while (true) - { - Find_shortcut find_shortcut; - init->traverse(&init, &find_shortcut); - Expression** pshortcut = find_shortcut.found(); - if (pshortcut == NULL) - return TRAVERSE_CONTINUE; - - Statement* snew = this->convert_shortcut(NULL, pshortcut); - var->add_preinit_statement(this->gogo_, snew); - if (pshortcut == &init) - var->set_init(init); - } -} - -// Given an expression which uses a shortcut operator, return a -// statement which implements it, and update *PSHORTCUT accordingly. - -Statement* -Shortcuts::convert_shortcut(Block* enclosing, Expression** pshortcut) -{ - Binary_expression* shortcut = (*pshortcut)->binary_expression(); - Expression* left = shortcut->left(); - Expression* right = shortcut->right(); - Location loc = shortcut->location(); - - Block* retblock = new Block(enclosing, loc); - retblock->set_end_location(loc); - - Temporary_statement* ts = Statement::make_temporary(shortcut->type(), - left, loc); - retblock->add_statement(ts); - - Block* block = new Block(retblock, loc); - block->set_end_location(loc); - Expression* tmpref = Expression::make_temporary_reference(ts, loc); - Statement* assign = Statement::make_assignment(tmpref, right, loc); - block->add_statement(assign); - - Expression* cond = Expression::make_temporary_reference(ts, loc); - if (shortcut->binary_expression()->op() == OPERATOR_OROR) - cond = Expression::make_unary(OPERATOR_NOT, cond, loc); - - Statement* if_statement = Statement::make_if_statement(cond, block, NULL, - loc); - retblock->add_statement(if_statement); - - *pshortcut = Expression::make_temporary_reference(ts, loc); - - delete shortcut; - - // Now convert any shortcut operators in LEFT and RIGHT. - Shortcuts shortcuts(this->gogo_); - retblock->traverse(&shortcuts); - - return Statement::make_block_statement(retblock, loc); -} - -// Turn shortcut operators into explicit if statements. Doing this -// considerably simplifies the order of evaluation rules. - -void -Gogo::remove_shortcuts() -{ - Shortcuts shortcuts(this); - this->traverse(&shortcuts); -} - // A traversal class which finds all the expressions which must be // evaluated in order within a statement or larger expression. This // is used to implement the rules about order of evaluation. @@ -3689,6 +3485,18 @@ class Find_eval_ordering : public Traverse int Find_eval_ordering::expression(Expression** expression_pointer) { + Binary_expression* binexp = (*expression_pointer)->binary_expression(); + if (binexp != NULL + && (binexp->op() == OPERATOR_ANDAND || binexp->op() == OPERATOR_OROR)) + { + // Shortcut expressions may potentially have side effects which need + // to be ordered, so add them to the list. + // We don't order its subexpressions here since they may be evaluated + // conditionally. This is handled in remove_shortcuts. + this->exprs_.push_back(expression_pointer); + return TRAVERSE_SKIP_COMPONENTS; + } + // We have to look at subexpressions before this one. if ((*expression_pointer)->traverse_subexpressions(this) == TRAVERSE_EXIT) return TRAVERSE_EXIT; @@ -3925,6 +3733,215 @@ Gogo::order_evaluations() this->traverse(&order_eval); } +// A traversal class used to find a single shortcut operator within an +// expression. + +class Find_shortcut : public Traverse +{ + public: + Find_shortcut() + : Traverse(traverse_blocks + | traverse_statements + | traverse_expressions), + found_(NULL) + { } + + // A pointer to the expression which was found, or NULL if none was + // found. + Expression** + found() const + { return this->found_; } + + protected: + int + block(Block*) + { return TRAVERSE_SKIP_COMPONENTS; } + + int + statement(Block*, size_t*, Statement*) + { return TRAVERSE_SKIP_COMPONENTS; } + + int + expression(Expression**); + + private: + Expression** found_; +}; + +// Find a shortcut expression. + +int +Find_shortcut::expression(Expression** pexpr) +{ + Expression* expr = *pexpr; + Binary_expression* be = expr->binary_expression(); + if (be == NULL) + return TRAVERSE_CONTINUE; + Operator op = be->op(); + if (op != OPERATOR_OROR && op != OPERATOR_ANDAND) + return TRAVERSE_CONTINUE; + go_assert(this->found_ == NULL); + this->found_ = pexpr; + return TRAVERSE_EXIT; +} + +// A traversal class used to turn shortcut operators into explicit if +// statements. + +class Shortcuts : public Traverse +{ + public: + Shortcuts(Gogo* gogo) + : Traverse(traverse_variables + | traverse_statements), + gogo_(gogo) + { } + + protected: + int + variable(Named_object*); + + int + statement(Block*, size_t*, Statement*); + + private: + // Convert a shortcut operator. + Statement* + convert_shortcut(Block* enclosing, Expression** pshortcut); + + // The IR. + Gogo* gogo_; +}; + +// Remove shortcut operators in a single statement. + +int +Shortcuts::statement(Block* block, size_t* pindex, Statement* s) +{ + // FIXME: This approach doesn't work for switch statements, because + // we add the new statements before the whole switch when we need to + // instead add them just before the switch expression. The right + // fix is probably to lower switch statements with nonconstant cases + // to a series of conditionals. + if (s->switch_statement() != NULL) + return TRAVERSE_CONTINUE; + + while (true) + { + Find_shortcut find_shortcut; + + // If S is a variable declaration, then ordinary traversal won't + // do anything. We want to explicitly traverse the + // initialization expression if there is one. + Variable_declaration_statement* vds = s->variable_declaration_statement(); + Expression* init = NULL; + if (vds == NULL) + s->traverse_contents(&find_shortcut); + else + { + init = vds->var()->var_value()->init(); + if (init == NULL) + return TRAVERSE_CONTINUE; + init->traverse(&init, &find_shortcut); + } + Expression** pshortcut = find_shortcut.found(); + if (pshortcut == NULL) + return TRAVERSE_CONTINUE; + + Statement* snew = this->convert_shortcut(block, pshortcut); + block->insert_statement_before(*pindex, snew); + ++*pindex; + + if (pshortcut == &init) + vds->var()->var_value()->set_init(init); + } +} + +// Remove shortcut operators in the initializer of a global variable. + +int +Shortcuts::variable(Named_object* no) +{ + if (no->is_result_variable()) + return TRAVERSE_CONTINUE; + Variable* var = no->var_value(); + Expression* init = var->init(); + if (!var->is_global() || init == NULL) + return TRAVERSE_CONTINUE; + + while (true) + { + Find_shortcut find_shortcut; + init->traverse(&init, &find_shortcut); + Expression** pshortcut = find_shortcut.found(); + if (pshortcut == NULL) + return TRAVERSE_CONTINUE; + + Statement* snew = this->convert_shortcut(NULL, pshortcut); + var->add_preinit_statement(this->gogo_, snew); + if (pshortcut == &init) + var->set_init(init); + } +} + +// Given an expression which uses a shortcut operator, return a +// statement which implements it, and update *PSHORTCUT accordingly. + +Statement* +Shortcuts::convert_shortcut(Block* enclosing, Expression** pshortcut) +{ + Binary_expression* shortcut = (*pshortcut)->binary_expression(); + Expression* left = shortcut->left(); + Expression* right = shortcut->right(); + Location loc = shortcut->location(); + + Block* retblock = new Block(enclosing, loc); + retblock->set_end_location(loc); + + Temporary_statement* ts = Statement::make_temporary(shortcut->type(), + left, loc); + retblock->add_statement(ts); + + Block* block = new Block(retblock, loc); + block->set_end_location(loc); + Expression* tmpref = Expression::make_temporary_reference(ts, loc); + Statement* assign = Statement::make_assignment(tmpref, right, loc); + block->add_statement(assign); + + Expression* cond = Expression::make_temporary_reference(ts, loc); + if (shortcut->binary_expression()->op() == OPERATOR_OROR) + cond = Expression::make_unary(OPERATOR_NOT, cond, loc); + + Statement* if_statement = Statement::make_if_statement(cond, block, NULL, + loc); + retblock->add_statement(if_statement); + + *pshortcut = Expression::make_temporary_reference(ts, loc); + + delete shortcut; + + // Now convert any shortcut operators in LEFT and RIGHT. + // LEFT and RIGHT were skipped in the top level + // Gogo::order_evaluations. We need to order their + // components first. + Order_eval order_eval(this->gogo_); + retblock->traverse(&order_eval); + Shortcuts shortcuts(this->gogo_); + retblock->traverse(&shortcuts); + + return Statement::make_block_statement(retblock, loc); +} + +// Turn shortcut operators into explicit if statements. Doing this +// considerably simplifies the order of evaluation rules. + +void +Gogo::remove_shortcuts() +{ + Shortcuts shortcuts(this); + this->traverse(&shortcuts); +} + // Traversal to flatten parse tree after order of evaluation rules are applied. class Flatten : public Traverse |