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Diffstat (limited to 'gcc/go/gofrontend/statements.cc')
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diff --git a/gcc/go/gofrontend/statements.cc b/gcc/go/gofrontend/statements.cc new file mode 100644 index 000000000..c443519b7 --- /dev/null +++ b/gcc/go/gofrontend/statements.cc @@ -0,0 +1,5262 @@ +// statements.cc -- Go frontend statements. + +// 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 <gmp.h> + +#ifndef ENABLE_BUILD_WITH_CXX +extern "C" +{ +#endif + +#include "intl.h" +#include "tree.h" +#include "gimple.h" +#include "convert.h" +#include "tree-iterator.h" +#include "tree-flow.h" +#include "real.h" + +#ifndef ENABLE_BUILD_WITH_CXX +} +#endif + +#include "go-c.h" +#include "types.h" +#include "expressions.h" +#include "gogo.h" +#include "statements.h" + +// Class Statement. + +Statement::Statement(Statement_classification classification, + source_location location) + : classification_(classification), location_(location) +{ +} + +Statement::~Statement() +{ +} + +// Traverse the tree. The work of walking the components is handled +// by the subclasses. + +int +Statement::traverse(Block* block, size_t* pindex, Traverse* traverse) +{ + if (this->classification_ == STATEMENT_ERROR) + return TRAVERSE_CONTINUE; + + unsigned int traverse_mask = traverse->traverse_mask(); + + if ((traverse_mask & Traverse::traverse_statements) != 0) + { + int t = traverse->statement(block, pindex, this); + if (t == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + else if (t == TRAVERSE_SKIP_COMPONENTS) + return TRAVERSE_CONTINUE; + } + + // No point in checking traverse_mask here--a statement may contain + // other blocks or statements, and if we got here we always want to + // walk them. + return this->do_traverse(traverse); +} + +// Traverse the contents of a statement. + +int +Statement::traverse_contents(Traverse* traverse) +{ + return this->do_traverse(traverse); +} + +// Traverse assignments. + +bool +Statement::traverse_assignments(Traverse_assignments* tassign) +{ + if (this->classification_ == STATEMENT_ERROR) + return false; + return this->do_traverse_assignments(tassign); +} + +// Traverse an expression in a statement. This is a helper function +// for child classes. + +int +Statement::traverse_expression(Traverse* traverse, Expression** expr) +{ + if ((traverse->traverse_mask() + & (Traverse::traverse_types | Traverse::traverse_expressions)) == 0) + return TRAVERSE_CONTINUE; + return Expression::traverse(expr, traverse); +} + +// Traverse an expression list in a statement. This is a helper +// function for child classes. + +int +Statement::traverse_expression_list(Traverse* traverse, + Expression_list* expr_list) +{ + if (expr_list == NULL) + return TRAVERSE_CONTINUE; + if ((traverse->traverse_mask() + & (Traverse::traverse_types | Traverse::traverse_expressions)) == 0) + return TRAVERSE_CONTINUE; + return expr_list->traverse(traverse); +} + +// Traverse a type in a statement. This is a helper function for +// child classes. + +int +Statement::traverse_type(Traverse* traverse, Type* type) +{ + if ((traverse->traverse_mask() + & (Traverse::traverse_types | Traverse::traverse_expressions)) == 0) + return TRAVERSE_CONTINUE; + return Type::traverse(type, traverse); +} + +// Set type information for unnamed constants. This is really done by +// the child class. + +void +Statement::determine_types() +{ + this->do_determine_types(); +} + +// If this is a thunk statement, return it. + +Thunk_statement* +Statement::thunk_statement() +{ + Thunk_statement* ret = this->convert<Thunk_statement, STATEMENT_GO>(); + if (ret == NULL) + ret = this->convert<Thunk_statement, STATEMENT_DEFER>(); + return ret; +} + +// Get a tree for a Statement. This is really done by the child +// class. + +tree +Statement::get_tree(Translate_context* context) +{ + if (this->classification_ == STATEMENT_ERROR) + return error_mark_node; + + return this->do_get_tree(context); +} + +// Build tree nodes and set locations. + +tree +Statement::build_stmt_1(int tree_code_value, tree node) +{ + tree ret = build1(static_cast<tree_code>(tree_code_value), + void_type_node, node); + SET_EXPR_LOCATION(ret, this->location_); + return ret; +} + +// Note that this statement is erroneous. This is called by children +// when they discover an error. + +void +Statement::set_is_error() +{ + this->classification_ = STATEMENT_ERROR; +} + +// For children to call to report an error conveniently. + +void +Statement::report_error(const char* msg) +{ + error_at(this->location_, "%s", msg); + this->set_is_error(); +} + +// An error statement, used to avoid crashing after we report an +// error. + +class Error_statement : public Statement +{ + public: + Error_statement(source_location location) + : Statement(STATEMENT_ERROR, location) + { } + + protected: + int + do_traverse(Traverse*) + { return TRAVERSE_CONTINUE; } + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } +}; + +// Make an error statement. + +Statement* +Statement::make_error_statement(source_location location) +{ + return new Error_statement(location); +} + +// Class Variable_declaration_statement. + +Variable_declaration_statement::Variable_declaration_statement( + Named_object* var) + : Statement(STATEMENT_VARIABLE_DECLARATION, var->var_value()->location()), + var_(var) +{ +} + +// We don't actually traverse the variable here; it was traversed +// while traversing the Block. + +int +Variable_declaration_statement::do_traverse(Traverse*) +{ + return TRAVERSE_CONTINUE; +} + +// Traverse the assignments in a variable declaration. Note that this +// traversal is different from the usual traversal. + +bool +Variable_declaration_statement::do_traverse_assignments( + Traverse_assignments* tassign) +{ + tassign->initialize_variable(this->var_); + return true; +} + +// Return the tree for a variable declaration. + +tree +Variable_declaration_statement::do_get_tree(Translate_context* context) +{ + tree val = this->var_->get_tree(context->gogo(), context->function()); + if (val == error_mark_node || TREE_TYPE(val) == error_mark_node) + return error_mark_node; + Variable* variable = this->var_->var_value(); + + tree init = variable->get_init_tree(context->gogo(), context->function()); + if (init == error_mark_node) + return error_mark_node; + + // If this variable lives on the heap, we need to allocate it now. + if (!variable->is_in_heap()) + { + DECL_INITIAL(val) = init; + return this->build_stmt_1(DECL_EXPR, val); + } + else + { + gcc_assert(TREE_CODE(val) == INDIRECT_REF); + tree decl = TREE_OPERAND(val, 0); + gcc_assert(TREE_CODE(decl) == VAR_DECL); + tree type = TREE_TYPE(decl); + gcc_assert(POINTER_TYPE_P(type)); + tree size = TYPE_SIZE_UNIT(TREE_TYPE(type)); + tree space = context->gogo()->allocate_memory(variable->type(), size, + this->location()); + space = fold_convert(TREE_TYPE(decl), space); + DECL_INITIAL(decl) = space; + return build2(COMPOUND_EXPR, void_type_node, + this->build_stmt_1(DECL_EXPR, decl), + build2(MODIFY_EXPR, void_type_node, val, init)); + } +} + +// Make a variable declaration. + +Statement* +Statement::make_variable_declaration(Named_object* var) +{ + return new Variable_declaration_statement(var); +} + +// Class Temporary_statement. + +// Return the type of the temporary variable. + +Type* +Temporary_statement::type() const +{ + return this->type_ != NULL ? this->type_ : this->init_->type(); +} + +// Return the tree for the temporary variable. + +tree +Temporary_statement::get_decl() const +{ + if (this->decl_ == NULL) + { + gcc_assert(saw_errors()); + return error_mark_node; + } + return this->decl_; +} + +// Traversal. + +int +Temporary_statement::do_traverse(Traverse* traverse) +{ + if (this->type_ != NULL + && this->traverse_type(traverse, this->type_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->init_ == NULL) + return TRAVERSE_CONTINUE; + else + return this->traverse_expression(traverse, &this->init_); +} + +// Traverse assignments. + +bool +Temporary_statement::do_traverse_assignments(Traverse_assignments* tassign) +{ + if (this->init_ == NULL) + return false; + tassign->value(&this->init_, true, true); + return true; +} + +// Determine types. + +void +Temporary_statement::do_determine_types() +{ + if (this->type_ != NULL && this->type_->is_abstract()) + this->type_ = this->type_->make_non_abstract_type(); + + if (this->init_ != NULL) + { + if (this->type_ == NULL) + this->init_->determine_type_no_context(); + else + { + Type_context context(this->type_, false); + this->init_->determine_type(&context); + } + } + + if (this->type_ == NULL) + { + this->type_ = this->init_->type(); + gcc_assert(!this->type_->is_abstract()); + } +} + +// Check types. + +void +Temporary_statement::do_check_types(Gogo*) +{ + if (this->type_ != NULL && this->init_ != NULL) + { + std::string reason; + if (!Type::are_assignable(this->type_, this->init_->type(), &reason)) + { + if (reason.empty()) + error_at(this->location(), "incompatible types in assignment"); + else + error_at(this->location(), "incompatible types in assignment (%s)", + reason.c_str()); + this->set_is_error(); + } + } +} + +// Return a tree. + +tree +Temporary_statement::do_get_tree(Translate_context* context) +{ + gcc_assert(this->decl_ == NULL_TREE); + tree type_tree = this->type()->get_tree(context->gogo()); + tree init_tree = (this->init_ == NULL + ? NULL_TREE + : this->init_->get_tree(context)); + if (type_tree == error_mark_node || init_tree == error_mark_node) + { + this->decl_ = error_mark_node; + return error_mark_node; + } + // We can only use create_tmp_var if the type is not addressable. + if (!TREE_ADDRESSABLE(type_tree)) + { + this->decl_ = create_tmp_var(type_tree, "GOTMP"); + DECL_SOURCE_LOCATION(this->decl_) = this->location(); + } + else + { + gcc_assert(context->function() != NULL && context->block() != NULL); + tree decl = build_decl(this->location(), VAR_DECL, + create_tmp_var_name("GOTMP"), + type_tree); + DECL_ARTIFICIAL(decl) = 1; + DECL_IGNORED_P(decl) = 1; + TREE_USED(decl) = 1; + gcc_assert(current_function_decl != NULL_TREE); + DECL_CONTEXT(decl) = current_function_decl; + + // We have to add this variable to the block so that it winds up + // in a BIND_EXPR. + tree block_tree = context->block_tree(); + gcc_assert(block_tree != NULL_TREE); + DECL_CHAIN(decl) = BLOCK_VARS(block_tree); + BLOCK_VARS(block_tree) = decl; + + this->decl_ = decl; + } + if (init_tree != NULL_TREE) + DECL_INITIAL(this->decl_) = + Expression::convert_for_assignment(context, this->type(), + this->init_->type(), init_tree, + this->location()); + if (this->is_address_taken_) + TREE_ADDRESSABLE(this->decl_) = 1; + return this->build_stmt_1(DECL_EXPR, this->decl_); +} + +// Make and initialize a temporary variable in BLOCK. + +Temporary_statement* +Statement::make_temporary(Type* type, Expression* init, + source_location location) +{ + return new Temporary_statement(type, init, location); +} + +// An assignment statement. + +class Assignment_statement : public Statement +{ + public: + Assignment_statement(Expression* lhs, Expression* rhs, + source_location location) + : Statement(STATEMENT_ASSIGNMENT, location), + lhs_(lhs), rhs_(rhs) + { } + + protected: + int + do_traverse(Traverse* traverse); + + bool + do_traverse_assignments(Traverse_assignments*); + + void + do_determine_types(); + + void + do_check_types(Gogo*); + + tree + do_get_tree(Translate_context*); + + private: + // Left hand side--the lvalue. + Expression* lhs_; + // Right hand side--the rvalue. + Expression* rhs_; +}; + +// Traversal. + +int +Assignment_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->lhs_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression(traverse, &this->rhs_); +} + +bool +Assignment_statement::do_traverse_assignments(Traverse_assignments* tassign) +{ + tassign->assignment(&this->lhs_, &this->rhs_); + return true; +} + +// Set types for the assignment. + +void +Assignment_statement::do_determine_types() +{ + this->lhs_->determine_type_no_context(); + Type_context context(this->lhs_->type(), false); + this->rhs_->determine_type(&context); +} + +// Check types for an assignment. + +void +Assignment_statement::do_check_types(Gogo*) +{ + // The left hand side must be either addressable, a map index + // expression, or the blank identifier. + if (!this->lhs_->is_addressable() + && this->lhs_->map_index_expression() == NULL + && !this->lhs_->is_sink_expression()) + { + if (!this->lhs_->type()->is_error_type()) + this->report_error(_("invalid left hand side of assignment")); + return; + } + + Type* lhs_type = this->lhs_->type(); + Type* rhs_type = this->rhs_->type(); + std::string reason; + if (!Type::are_assignable(lhs_type, rhs_type, &reason)) + { + if (reason.empty()) + error_at(this->location(), "incompatible types in assignment"); + else + error_at(this->location(), "incompatible types in assignment (%s)", + reason.c_str()); + this->set_is_error(); + } + + if (lhs_type->is_error_type() + || rhs_type->is_error_type() + || lhs_type->is_undefined() + || rhs_type->is_undefined()) + { + // Make sure we get the error for an undefined type. + lhs_type->base(); + rhs_type->base(); + this->set_is_error(); + } +} + +// Build a tree for an assignment statement. + +tree +Assignment_statement::do_get_tree(Translate_context* context) +{ + tree rhs_tree = this->rhs_->get_tree(context); + + if (this->lhs_->is_sink_expression()) + return rhs_tree; + + tree lhs_tree = this->lhs_->get_tree(context); + + if (lhs_tree == error_mark_node || rhs_tree == error_mark_node) + return error_mark_node; + + rhs_tree = Expression::convert_for_assignment(context, this->lhs_->type(), + this->rhs_->type(), rhs_tree, + this->location()); + if (rhs_tree == error_mark_node) + return error_mark_node; + + return fold_build2_loc(this->location(), MODIFY_EXPR, void_type_node, + lhs_tree, rhs_tree); +} + +// Make an assignment statement. + +Statement* +Statement::make_assignment(Expression* lhs, Expression* rhs, + source_location location) +{ + return new Assignment_statement(lhs, rhs, location); +} + +// The Move_ordered_evals class is used to find any subexpressions of +// an expression that have an evaluation order dependency. It creates +// temporary variables to hold them. + +class Move_ordered_evals : public Traverse +{ + public: + Move_ordered_evals(Block* block) + : Traverse(traverse_expressions), + block_(block) + { } + + protected: + int + expression(Expression**); + + private: + // The block where new temporary variables should be added. + Block* block_; +}; + +int +Move_ordered_evals::expression(Expression** pexpr) +{ + // We have to look at subexpressions first. + if ((*pexpr)->traverse_subexpressions(this) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if ((*pexpr)->must_eval_in_order()) + { + source_location loc = (*pexpr)->location(); + Temporary_statement* temp = Statement::make_temporary(NULL, *pexpr, loc); + this->block_->add_statement(temp); + *pexpr = Expression::make_temporary_reference(temp, loc); + } + return TRAVERSE_SKIP_COMPONENTS; +} + +// An assignment operation statement. + +class Assignment_operation_statement : public Statement +{ + public: + Assignment_operation_statement(Operator op, Expression* lhs, Expression* rhs, + source_location location) + : Statement(STATEMENT_ASSIGNMENT_OPERATION, location), + op_(op), lhs_(lhs), rhs_(rhs) + { } + + protected: + int + do_traverse(Traverse*); + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + // The operator (OPERATOR_PLUSEQ, etc.). + Operator op_; + // Left hand side. + Expression* lhs_; + // Right hand side. + Expression* rhs_; +}; + +// Traversal. + +int +Assignment_operation_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->lhs_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression(traverse, &this->rhs_); +} + +// Lower an assignment operation statement to a regular assignment +// statement. + +Statement* +Assignment_operation_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + // We have to evaluate the left hand side expression only once. We + // do this by moving out any expression with side effects. + Block* b = new Block(enclosing, loc); + Move_ordered_evals moe(b); + this->lhs_->traverse_subexpressions(&moe); + + Expression* lval = this->lhs_->copy(); + + Operator op; + switch (this->op_) + { + case OPERATOR_PLUSEQ: + op = OPERATOR_PLUS; + break; + case OPERATOR_MINUSEQ: + op = OPERATOR_MINUS; + break; + case OPERATOR_OREQ: + op = OPERATOR_OR; + break; + case OPERATOR_XOREQ: + op = OPERATOR_XOR; + break; + case OPERATOR_MULTEQ: + op = OPERATOR_MULT; + break; + case OPERATOR_DIVEQ: + op = OPERATOR_DIV; + break; + case OPERATOR_MODEQ: + op = OPERATOR_MOD; + break; + case OPERATOR_LSHIFTEQ: + op = OPERATOR_LSHIFT; + break; + case OPERATOR_RSHIFTEQ: + op = OPERATOR_RSHIFT; + break; + case OPERATOR_ANDEQ: + op = OPERATOR_AND; + break; + case OPERATOR_BITCLEAREQ: + op = OPERATOR_BITCLEAR; + break; + default: + gcc_unreachable(); + } + + Expression* binop = Expression::make_binary(op, lval, this->rhs_, loc); + Statement* s = Statement::make_assignment(this->lhs_, binop, loc); + if (b->statements()->empty()) + { + delete b; + return s; + } + else + { + b->add_statement(s); + return Statement::make_block_statement(b, loc); + } +} + +// Make an assignment operation statement. + +Statement* +Statement::make_assignment_operation(Operator op, Expression* lhs, + Expression* rhs, source_location location) +{ + return new Assignment_operation_statement(op, lhs, rhs, location); +} + +// A tuple assignment statement. This differs from an assignment +// statement in that the right-hand-side expressions are evaluated in +// parallel. + +class Tuple_assignment_statement : public Statement +{ + public: + Tuple_assignment_statement(Expression_list* lhs, Expression_list* rhs, + source_location location) + : Statement(STATEMENT_TUPLE_ASSIGNMENT, location), + lhs_(lhs), rhs_(rhs) + { } + + protected: + int + do_traverse(Traverse* traverse); + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + // Left hand side--a list of lvalues. + Expression_list* lhs_; + // Right hand side--a list of rvalues. + Expression_list* rhs_; +}; + +// Traversal. + +int +Tuple_assignment_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression_list(traverse, this->lhs_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression_list(traverse, this->rhs_); +} + +// Lower a tuple assignment. We use temporary variables to split it +// up into a set of single assignments. + +Statement* +Tuple_assignment_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + Block* b = new Block(enclosing, loc); + + // First move out any subexpressions on the left hand side. The + // right hand side will be evaluated in the required order anyhow. + Move_ordered_evals moe(b); + for (Expression_list::const_iterator plhs = this->lhs_->begin(); + plhs != this->lhs_->end(); + ++plhs) + (*plhs)->traverse_subexpressions(&moe); + + std::vector<Temporary_statement*> temps; + temps.reserve(this->lhs_->size()); + + Expression_list::const_iterator prhs = this->rhs_->begin(); + for (Expression_list::const_iterator plhs = this->lhs_->begin(); + plhs != this->lhs_->end(); + ++plhs, ++prhs) + { + gcc_assert(prhs != this->rhs_->end()); + + if ((*plhs)->is_error_expression() + || (*plhs)->type()->is_error_type() + || (*prhs)->is_error_expression() + || (*prhs)->type()->is_error_type()) + continue; + + if ((*plhs)->is_sink_expression()) + { + b->add_statement(Statement::make_statement(*prhs)); + continue; + } + + Temporary_statement* temp = Statement::make_temporary((*plhs)->type(), + *prhs, loc); + b->add_statement(temp); + temps.push_back(temp); + + } + gcc_assert(prhs == this->rhs_->end()); + + prhs = this->rhs_->begin(); + std::vector<Temporary_statement*>::const_iterator ptemp = temps.begin(); + for (Expression_list::const_iterator plhs = this->lhs_->begin(); + plhs != this->lhs_->end(); + ++plhs, ++prhs) + { + if ((*plhs)->is_error_expression() + || (*plhs)->type()->is_error_type() + || (*prhs)->is_error_expression() + || (*prhs)->type()->is_error_type()) + continue; + + if ((*plhs)->is_sink_expression()) + continue; + + Expression* ref = Expression::make_temporary_reference(*ptemp, loc); + Statement* s = Statement::make_assignment(*plhs, ref, loc); + b->add_statement(s); + ++ptemp; + } + gcc_assert(ptemp == temps.end()); + + return Statement::make_block_statement(b, loc); +} + +// Make a tuple assignment statement. + +Statement* +Statement::make_tuple_assignment(Expression_list* lhs, Expression_list* rhs, + source_location location) +{ + return new Tuple_assignment_statement(lhs, rhs, location); +} + +// A tuple assignment from a map index expression. +// v, ok = m[k] + +class Tuple_map_assignment_statement : public Statement +{ +public: + Tuple_map_assignment_statement(Expression* val, Expression* present, + Expression* map_index, + source_location location) + : Statement(STATEMENT_TUPLE_MAP_ASSIGNMENT, location), + val_(val), present_(present), map_index_(map_index) + { } + + protected: + int + do_traverse(Traverse* traverse); + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + // Lvalue which receives the value from the map. + Expression* val_; + // Lvalue which receives whether the key value was present. + Expression* present_; + // The map index expression. + Expression* map_index_; +}; + +// Traversal. + +int +Tuple_map_assignment_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT + || this->traverse_expression(traverse, &this->present_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression(traverse, &this->map_index_); +} + +// Lower a tuple map assignment. + +Statement* +Tuple_map_assignment_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + Map_index_expression* map_index = this->map_index_->map_index_expression(); + if (map_index == NULL) + { + this->report_error(_("expected map index on right hand side")); + return Statement::make_error_statement(loc); + } + Map_type* map_type = map_index->get_map_type(); + if (map_type == NULL) + return Statement::make_error_statement(loc); + + Block* b = new Block(enclosing, loc); + + // Move out any subexpressions to make sure that functions are + // called in the required order. + Move_ordered_evals moe(b); + this->val_->traverse_subexpressions(&moe); + this->present_->traverse_subexpressions(&moe); + + // Copy the key value into a temporary so that we can take its + // address without pushing the value onto the heap. + + // var key_temp KEY_TYPE = MAP_INDEX + Temporary_statement* key_temp = + Statement::make_temporary(map_type->key_type(), map_index->index(), loc); + b->add_statement(key_temp); + + // var val_temp VAL_TYPE + Temporary_statement* val_temp = + Statement::make_temporary(map_type->val_type(), NULL, loc); + b->add_statement(val_temp); + + // var present_temp bool + Temporary_statement* present_temp = + Statement::make_temporary(Type::lookup_bool_type(), NULL, loc); + b->add_statement(present_temp); + + // func mapaccess2(hmap map[k]v, key *k, val *v) bool + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("hmap", map_type, bloc)); + Type* pkey_type = Type::make_pointer_type(map_type->key_type()); + param_types->push_back(Typed_identifier("key", pkey_type, bloc)); + Type* pval_type = Type::make_pointer_type(map_type->val_type()); + param_types->push_back(Typed_identifier("val", pval_type, bloc)); + + Typed_identifier_list* ret_types = new Typed_identifier_list(); + ret_types->push_back(Typed_identifier("", Type::lookup_bool_type(), bloc)); + + Function_type* fntype = Type::make_function_type(NULL, param_types, + ret_types, bloc); + Named_object* mapaccess2 = + Named_object::make_function_declaration("mapaccess2", NULL, fntype, bloc); + mapaccess2->func_declaration_value()->set_asm_name("runtime.mapaccess2"); + + // present_temp = mapaccess2(MAP, &key_temp, &val_temp) + Expression* func = Expression::make_func_reference(mapaccess2, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(map_index->map()); + Expression* ref = Expression::make_temporary_reference(key_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + ref = Expression::make_temporary_reference(val_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + Expression* call = Expression::make_call(func, params, false, loc); + + ref = Expression::make_temporary_reference(present_temp, loc); + Statement* s = Statement::make_assignment(ref, call, loc); + b->add_statement(s); + + // val = val_temp + ref = Expression::make_temporary_reference(val_temp, loc); + s = Statement::make_assignment(this->val_, ref, loc); + b->add_statement(s); + + // present = present_temp + ref = Expression::make_temporary_reference(present_temp, loc); + s = Statement::make_assignment(this->present_, ref, loc); + b->add_statement(s); + + return Statement::make_block_statement(b, loc); +} + +// Make a map assignment statement which returns a pair of values. + +Statement* +Statement::make_tuple_map_assignment(Expression* val, Expression* present, + Expression* map_index, + source_location location) +{ + return new Tuple_map_assignment_statement(val, present, map_index, location); +} + +// Assign a pair of entries to a map. +// m[k] = v, p + +class Map_assignment_statement : public Statement +{ + public: + Map_assignment_statement(Expression* map_index, + Expression* val, Expression* should_set, + source_location location) + : Statement(STATEMENT_MAP_ASSIGNMENT, location), + map_index_(map_index), val_(val), should_set_(should_set) + { } + + protected: + int + do_traverse(Traverse* traverse); + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + // A reference to the map index which should be set or deleted. + Expression* map_index_; + // The value to add to the map. + Expression* val_; + // Whether or not to add the value. + Expression* should_set_; +}; + +// Traverse a map assignment. + +int +Map_assignment_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->map_index_) == TRAVERSE_EXIT + || this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression(traverse, &this->should_set_); +} + +// Lower a map assignment to a function call. + +Statement* +Map_assignment_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + Map_index_expression* map_index = this->map_index_->map_index_expression(); + if (map_index == NULL) + { + this->report_error(_("expected map index on left hand side")); + return Statement::make_error_statement(loc); + } + Map_type* map_type = map_index->get_map_type(); + if (map_type == NULL) + return Statement::make_error_statement(loc); + + Block* b = new Block(enclosing, loc); + + // Evaluate the map first to get order of evaluation right. + // map_temp := m // we are evaluating m[k] = v, p + Temporary_statement* map_temp = Statement::make_temporary(map_type, + map_index->map(), + loc); + b->add_statement(map_temp); + + // var key_temp MAP_KEY_TYPE = k + Temporary_statement* key_temp = + Statement::make_temporary(map_type->key_type(), map_index->index(), loc); + b->add_statement(key_temp); + + // var val_temp MAP_VAL_TYPE = v + Temporary_statement* val_temp = + Statement::make_temporary(map_type->val_type(), this->val_, loc); + b->add_statement(val_temp); + + // func mapassign2(hmap map[k]v, key *k, val *v, p) + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("hmap", map_type, bloc)); + Type* pkey_type = Type::make_pointer_type(map_type->key_type()); + param_types->push_back(Typed_identifier("key", pkey_type, bloc)); + Type* pval_type = Type::make_pointer_type(map_type->val_type()); + param_types->push_back(Typed_identifier("val", pval_type, bloc)); + param_types->push_back(Typed_identifier("p", Type::lookup_bool_type(), bloc)); + Function_type* fntype = Type::make_function_type(NULL, param_types, + NULL, bloc); + Named_object* mapassign2 = + Named_object::make_function_declaration("mapassign2", NULL, fntype, bloc); + mapassign2->func_declaration_value()->set_asm_name("runtime.mapassign2"); + + // mapassign2(map_temp, &key_temp, &val_temp, p) + Expression* func = Expression::make_func_reference(mapassign2, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(Expression::make_temporary_reference(map_temp, loc)); + Expression* ref = Expression::make_temporary_reference(key_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + ref = Expression::make_temporary_reference(val_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + params->push_back(this->should_set_); + Expression* call = Expression::make_call(func, params, false, loc); + Statement* s = Statement::make_statement(call); + b->add_statement(s); + + return Statement::make_block_statement(b, loc); +} + +// Make a statement which assigns a pair of entries to a map. + +Statement* +Statement::make_map_assignment(Expression* map_index, + Expression* val, Expression* should_set, + source_location location) +{ + return new Map_assignment_statement(map_index, val, should_set, location); +} + +// A tuple assignment from a receive statement. + +class Tuple_receive_assignment_statement : public Statement +{ + public: + Tuple_receive_assignment_statement(Expression* val, Expression* success, + Expression* channel, + source_location location) + : Statement(STATEMENT_TUPLE_RECEIVE_ASSIGNMENT, location), + val_(val), success_(success), channel_(channel) + { } + + protected: + int + do_traverse(Traverse* traverse); + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + // Lvalue which receives the value from the channel. + Expression* val_; + // Lvalue which receives whether the read succeeded or failed. + Expression* success_; + // The channel on which we receive the value. + Expression* channel_; +}; + +// Traversal. + +int +Tuple_receive_assignment_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT + || this->traverse_expression(traverse, &this->success_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression(traverse, &this->channel_); +} + +// Lower to a function call. + +Statement* +Tuple_receive_assignment_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + Channel_type* channel_type = this->channel_->type()->channel_type(); + if (channel_type == NULL) + { + this->report_error(_("expected channel")); + return Statement::make_error_statement(loc); + } + if (!channel_type->may_receive()) + { + this->report_error(_("invalid receive on send-only channel")); + return Statement::make_error_statement(loc); + } + + Block* b = new Block(enclosing, loc); + + // Make sure that any subexpressions on the left hand side are + // evaluated in the right order. + Move_ordered_evals moe(b); + this->val_->traverse_subexpressions(&moe); + this->success_->traverse_subexpressions(&moe); + + // var val_temp ELEMENT_TYPE + Temporary_statement* val_temp = + Statement::make_temporary(channel_type->element_type(), NULL, loc); + b->add_statement(val_temp); + + // var success_temp bool + Temporary_statement* success_temp = + Statement::make_temporary(Type::lookup_bool_type(), NULL, loc); + b->add_statement(success_temp); + + // func chanrecv2(c chan T, val *T) bool + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("c", channel_type, bloc)); + Type* pelement_type = Type::make_pointer_type(channel_type->element_type()); + param_types->push_back(Typed_identifier("val", pelement_type, bloc)); + + Typed_identifier_list* ret_types = new Typed_identifier_list(); + ret_types->push_back(Typed_identifier("", Type::lookup_bool_type(), bloc)); + + Function_type* fntype = Type::make_function_type(NULL, param_types, + ret_types, bloc); + Named_object* chanrecv2 = + Named_object::make_function_declaration("chanrecv2", NULL, fntype, bloc); + chanrecv2->func_declaration_value()->set_asm_name("runtime.chanrecv2"); + + // success_temp = chanrecv2(channel, &val_temp) + Expression* func = Expression::make_func_reference(chanrecv2, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(this->channel_); + Expression* ref = Expression::make_temporary_reference(val_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + Expression* call = Expression::make_call(func, params, false, loc); + ref = Expression::make_temporary_reference(success_temp, loc); + Statement* s = Statement::make_assignment(ref, call, loc); + b->add_statement(s); + + // val = val_temp + ref = Expression::make_temporary_reference(val_temp, loc); + s = Statement::make_assignment(this->val_, ref, loc); + b->add_statement(s); + + // success = success_temp + ref = Expression::make_temporary_reference(success_temp, loc); + s = Statement::make_assignment(this->success_, ref, loc); + b->add_statement(s); + + return Statement::make_block_statement(b, loc); +} + +// Make a nonblocking receive statement. + +Statement* +Statement::make_tuple_receive_assignment(Expression* val, Expression* success, + Expression* channel, + source_location location) +{ + return new Tuple_receive_assignment_statement(val, success, channel, + location); +} + +// An assignment to a pair of values from a type guard. This is a +// conditional type guard. v, ok = i.(type). + +class Tuple_type_guard_assignment_statement : public Statement +{ + public: + Tuple_type_guard_assignment_statement(Expression* val, Expression* ok, + Expression* expr, Type* type, + source_location location) + : Statement(STATEMENT_TUPLE_TYPE_GUARD_ASSIGNMENT, location), + val_(val), ok_(ok), expr_(expr), type_(type) + { } + + protected: + int + do_traverse(Traverse*); + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + Call_expression* + lower_to_empty_interface(const char*); + + Call_expression* + lower_to_type(const char*); + + void + lower_to_object_type(Block*, const char*); + + // The variable which recieves the converted value. + Expression* val_; + // The variable which receives the indication of success. + Expression* ok_; + // The expression being converted. + Expression* expr_; + // The type to which the expression is being converted. + Type* type_; +}; + +// Traverse a type guard tuple assignment. + +int +Tuple_type_guard_assignment_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT + || this->traverse_expression(traverse, &this->ok_) == TRAVERSE_EXIT + || this->traverse_type(traverse, this->type_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->traverse_expression(traverse, &this->expr_); +} + +// Lower to a function call. + +Statement* +Tuple_type_guard_assignment_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + Type* expr_type = this->expr_->type(); + if (expr_type->interface_type() == NULL) + { + if (!expr_type->is_error_type() && !this->type_->is_error_type()) + this->report_error(_("type assertion only valid for interface types")); + return Statement::make_error_statement(loc); + } + + Block* b = new Block(enclosing, loc); + + // Make sure that any subexpressions on the left hand side are + // evaluated in the right order. + Move_ordered_evals moe(b); + this->val_->traverse_subexpressions(&moe); + this->ok_->traverse_subexpressions(&moe); + + bool expr_is_empty = expr_type->interface_type()->is_empty(); + Call_expression* call; + if (this->type_->interface_type() != NULL) + { + if (this->type_->interface_type()->is_empty()) + call = this->lower_to_empty_interface(expr_is_empty + ? "ifaceE2E2" + : "ifaceI2E2"); + else + call = this->lower_to_type(expr_is_empty ? "ifaceE2I2" : "ifaceI2I2"); + } + else if (this->type_->points_to() != NULL) + call = this->lower_to_type(expr_is_empty ? "ifaceE2T2P" : "ifaceI2T2P"); + else + { + this->lower_to_object_type(b, expr_is_empty ? "ifaceE2T2" : "ifaceI2T2"); + call = NULL; + } + + if (call != NULL) + { + Expression* res = Expression::make_call_result(call, 0); + Statement* s = Statement::make_assignment(this->val_, res, loc); + b->add_statement(s); + + res = Expression::make_call_result(call, 1); + s = Statement::make_assignment(this->ok_, res, loc); + b->add_statement(s); + } + + return Statement::make_block_statement(b, loc); +} + +// Lower a conversion to an empty interface type. + +Call_expression* +Tuple_type_guard_assignment_statement::lower_to_empty_interface( + const char *fnname) +{ + source_location loc = this->location(); + + // func FNNAME(interface) (empty, bool) + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("i", this->expr_->type(), bloc)); + Typed_identifier_list* ret_types = new Typed_identifier_list(); + ret_types->push_back(Typed_identifier("ret", this->type_, bloc)); + ret_types->push_back(Typed_identifier("ok", Type::lookup_bool_type(), bloc)); + Function_type* fntype = Type::make_function_type(NULL, param_types, + ret_types, bloc); + Named_object* fn = + Named_object::make_function_declaration(fnname, NULL, fntype, bloc); + std::string asm_name = "runtime."; + asm_name += fnname; + fn->func_declaration_value()->set_asm_name(asm_name); + + // val, ok = FNNAME(expr) + Expression* func = Expression::make_func_reference(fn, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(this->expr_); + return Expression::make_call(func, params, false, loc); +} + +// Lower a conversion to a non-empty interface type or a pointer type. + +Call_expression* +Tuple_type_guard_assignment_statement::lower_to_type(const char* fnname) +{ + source_location loc = this->location(); + + // func FNNAME(*descriptor, interface) (interface, bool) + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("inter", + Type::make_type_descriptor_ptr_type(), + bloc)); + param_types->push_back(Typed_identifier("i", this->expr_->type(), bloc)); + Typed_identifier_list* ret_types = new Typed_identifier_list(); + ret_types->push_back(Typed_identifier("ret", this->type_, bloc)); + ret_types->push_back(Typed_identifier("ok", Type::lookup_bool_type(), bloc)); + Function_type* fntype = Type::make_function_type(NULL, param_types, + ret_types, bloc); + Named_object* fn = + Named_object::make_function_declaration(fnname, NULL, fntype, bloc); + std::string asm_name = "runtime."; + asm_name += fnname; + fn->func_declaration_value()->set_asm_name(asm_name); + + // val, ok = FNNAME(type_descriptor, expr) + Expression* func = Expression::make_func_reference(fn, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(Expression::make_type_descriptor(this->type_, loc)); + params->push_back(this->expr_); + return Expression::make_call(func, params, false, loc); +} + +// Lower a conversion to a non-interface non-pointer type. + +void +Tuple_type_guard_assignment_statement::lower_to_object_type(Block* b, + const char *fnname) +{ + source_location loc = this->location(); + + // var val_temp TYPE + Temporary_statement* val_temp = Statement::make_temporary(this->type_, + NULL, loc); + b->add_statement(val_temp); + + // func FNNAME(*descriptor, interface, *T) bool + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("inter", + Type::make_type_descriptor_ptr_type(), + bloc)); + param_types->push_back(Typed_identifier("i", this->expr_->type(), bloc)); + Type* ptype = Type::make_pointer_type(this->type_); + param_types->push_back(Typed_identifier("v", ptype, bloc)); + Typed_identifier_list* ret_types = new Typed_identifier_list(); + ret_types->push_back(Typed_identifier("ok", Type::lookup_bool_type(), bloc)); + Function_type* fntype = Type::make_function_type(NULL, param_types, + ret_types, bloc); + Named_object* fn = + Named_object::make_function_declaration(fnname, NULL, fntype, bloc); + std::string asm_name = "runtime."; + asm_name += fnname; + fn->func_declaration_value()->set_asm_name(asm_name); + + // ok = FNNAME(type_descriptor, expr, &val_temp) + Expression* func = Expression::make_func_reference(fn, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(Expression::make_type_descriptor(this->type_, loc)); + params->push_back(this->expr_); + Expression* ref = Expression::make_temporary_reference(val_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + Expression* call = Expression::make_call(func, params, false, loc); + Statement* s = Statement::make_assignment(this->ok_, call, loc); + b->add_statement(s); + + // val = val_temp + ref = Expression::make_temporary_reference(val_temp, loc); + s = Statement::make_assignment(this->val_, ref, loc); + b->add_statement(s); +} + +// Make an assignment from a type guard to a pair of variables. + +Statement* +Statement::make_tuple_type_guard_assignment(Expression* val, Expression* ok, + Expression* expr, Type* type, + source_location location) +{ + return new Tuple_type_guard_assignment_statement(val, ok, expr, type, + location); +} + +// An expression statement. + +class Expression_statement : public Statement +{ + public: + Expression_statement(Expression* expr) + : Statement(STATEMENT_EXPRESSION, expr->location()), + expr_(expr) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return this->traverse_expression(traverse, &this->expr_); } + + void + do_determine_types() + { this->expr_->determine_type_no_context(); } + + bool + do_may_fall_through() const; + + tree + do_get_tree(Translate_context* context) + { return this->expr_->get_tree(context); } + + private: + Expression* expr_; +}; + +// An expression statement may fall through unless it is a call to a +// function which does not return. + +bool +Expression_statement::do_may_fall_through() const +{ + const Call_expression* call = this->expr_->call_expression(); + if (call != NULL) + { + const Expression* fn = call->fn(); + const Func_expression* fe = fn->func_expression(); + if (fe != NULL) + { + const Named_object* no = fe->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; + } + } + return true; +} + +// Make an expression statement from an Expression. + +Statement* +Statement::make_statement(Expression* expr) +{ + return new Expression_statement(expr); +} + +// A block statement--a list of statements which may include variable +// definitions. + +class Block_statement : public Statement +{ + public: + Block_statement(Block* block, source_location location) + : Statement(STATEMENT_BLOCK, location), + block_(block) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return this->block_->traverse(traverse); } + + void + do_determine_types() + { this->block_->determine_types(); } + + bool + do_may_fall_through() const + { return this->block_->may_fall_through(); } + + tree + do_get_tree(Translate_context* context) + { return this->block_->get_tree(context); } + + private: + Block* block_; +}; + +// Make a block statement. + +Statement* +Statement::make_block_statement(Block* block, source_location location) +{ + return new Block_statement(block, location); +} + +// An increment or decrement statement. + +class Inc_dec_statement : public Statement +{ + public: + Inc_dec_statement(bool is_inc, Expression* expr) + : Statement(STATEMENT_INCDEC, expr->location()), + expr_(expr), is_inc_(is_inc) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return this->traverse_expression(traverse, &this->expr_); } + + bool + do_traverse_assignments(Traverse_assignments*) + { gcc_unreachable(); } + + Statement* + do_lower(Gogo*, Block*); + + tree + do_get_tree(Translate_context*) + { gcc_unreachable(); } + + private: + // The l-value to increment or decrement. + Expression* expr_; + // Whether to increment or decrement. + bool is_inc_; +}; + +// Lower to += or -=. + +Statement* +Inc_dec_statement::do_lower(Gogo*, Block*) +{ + source_location loc = this->location(); + + mpz_t oval; + mpz_init_set_ui(oval, 1UL); + Expression* oexpr = Expression::make_integer(&oval, NULL, loc); + mpz_clear(oval); + + Operator op = this->is_inc_ ? OPERATOR_PLUSEQ : OPERATOR_MINUSEQ; + return Statement::make_assignment_operation(op, this->expr_, oexpr, loc); +} + +// Make an increment statement. + +Statement* +Statement::make_inc_statement(Expression* expr) +{ + return new Inc_dec_statement(true, expr); +} + +// Make a decrement statement. + +Statement* +Statement::make_dec_statement(Expression* expr) +{ + return new Inc_dec_statement(false, expr); +} + +// Class Thunk_statement. This is the base class for go and defer +// statements. + +const char* const Thunk_statement::thunk_field_fn = "fn"; + +const char* const Thunk_statement::thunk_field_receiver = "receiver"; + +// Constructor. + +Thunk_statement::Thunk_statement(Statement_classification classification, + Call_expression* call, + source_location location) + : Statement(classification, location), + call_(call), struct_type_(NULL) +{ +} + +// Return whether this is a simple statement which does not require a +// thunk. + +bool +Thunk_statement::is_simple(Function_type* fntype) const +{ + // We need a thunk to call a method, or to pass a variable number of + // arguments. + if (fntype->is_method() || fntype->is_varargs()) + return false; + + // A defer statement requires a thunk to set up for whether the + // function can call recover. + if (this->classification() == STATEMENT_DEFER) + return false; + + // We can only permit a single parameter of pointer type. + const Typed_identifier_list* parameters = fntype->parameters(); + if (parameters != NULL + && (parameters->size() > 1 + || (parameters->size() == 1 + && parameters->begin()->type()->points_to() == NULL))) + return false; + + // If the function returns multiple values, or returns a type other + // than integer, floating point, or pointer, then it may get a + // hidden first parameter, in which case we need the more + // complicated approach. This is true even though we are going to + // ignore the return value. + const Typed_identifier_list* results = fntype->results(); + if (results != NULL + && (results->size() > 1 + || (results->size() == 1 + && !results->begin()->type()->is_basic_type() + && results->begin()->type()->points_to() == NULL))) + return false; + + // If this calls something which is not a simple function, then we + // need a thunk. + Expression* fn = this->call_->call_expression()->fn(); + if (fn->bound_method_expression() != NULL + || fn->interface_field_reference_expression() != NULL) + return false; + + return true; +} + +// Traverse a thunk statement. + +int +Thunk_statement::do_traverse(Traverse* traverse) +{ + return this->traverse_expression(traverse, &this->call_); +} + +// We implement traverse_assignment for a thunk statement because it +// effectively copies the function call. + +bool +Thunk_statement::do_traverse_assignments(Traverse_assignments* tassign) +{ + Expression* fn = this->call_->call_expression()->fn(); + Expression* fn2 = fn; + tassign->value(&fn2, true, false); + return true; +} + +// Determine types in a thunk statement. + +void +Thunk_statement::do_determine_types() +{ + this->call_->determine_type_no_context(); + + // Now that we know the types of the call, build the struct used to + // pass parameters. + Call_expression* ce = this->call_->call_expression(); + if (ce == NULL) + return; + Function_type* fntype = ce->get_function_type(); + if (fntype != NULL && !this->is_simple(fntype)) + this->struct_type_ = this->build_struct(fntype); +} + +// Check types in a thunk statement. + +void +Thunk_statement::do_check_types(Gogo*) +{ + Call_expression* ce = this->call_->call_expression(); + if (ce == NULL) + { + if (!this->call_->is_error_expression()) + this->report_error("expected call expression"); + return; + } + Function_type* fntype = ce->get_function_type(); + if (fntype != NULL && fntype->is_method()) + { + Expression* fn = ce->fn(); + if (fn->bound_method_expression() == NULL + && fn->interface_field_reference_expression() == NULL) + this->report_error(_("no object for method call")); + } +} + +// The Traverse class used to find and simplify thunk statements. + +class Simplify_thunk_traverse : public Traverse +{ + public: + Simplify_thunk_traverse(Gogo* gogo) + : Traverse(traverse_blocks), + gogo_(gogo) + { } + + int + block(Block*); + + private: + Gogo* gogo_; +}; + +int +Simplify_thunk_traverse::block(Block* b) +{ + // The parser ensures that thunk statements always appear at the end + // of a block. + if (b->statements()->size() < 1) + return TRAVERSE_CONTINUE; + Thunk_statement* stat = b->statements()->back()->thunk_statement(); + if (stat == NULL) + return TRAVERSE_CONTINUE; + if (stat->simplify_statement(this->gogo_, b)) + return TRAVERSE_SKIP_COMPONENTS; + return TRAVERSE_CONTINUE; +} + +// Simplify all thunk statements. + +void +Gogo::simplify_thunk_statements() +{ + Simplify_thunk_traverse thunk_traverse(this); + this->traverse(&thunk_traverse); +} + +// Simplify complex thunk statements into simple ones. A complicated +// thunk statement is one which takes anything other than zero +// parameters or a single pointer parameter. We rewrite it into code +// which allocates a struct, stores the parameter values into the +// struct, and does a simple go or defer statement which passes the +// struct to a thunk. The thunk does the real call. + +bool +Thunk_statement::simplify_statement(Gogo* gogo, Block* block) +{ + if (this->classification() == STATEMENT_ERROR) + return false; + if (this->call_->is_error_expression()) + return false; + + Call_expression* ce = this->call_->call_expression(); + Function_type* fntype = ce->get_function_type(); + if (fntype == NULL) + { + gcc_assert(saw_errors()); + this->set_is_error(); + return false; + } + if (this->is_simple(fntype)) + return false; + + Expression* fn = ce->fn(); + Bound_method_expression* bound_method = fn->bound_method_expression(); + Interface_field_reference_expression* interface_method = + fn->interface_field_reference_expression(); + const bool is_method = bound_method != NULL || interface_method != NULL; + + source_location location = this->location(); + + std::string thunk_name = Gogo::thunk_name(); + + // Build the thunk. + this->build_thunk(gogo, thunk_name, fntype); + + // Generate code to call the thunk. + + // Get the values to store into the struct which is the single + // argument to the thunk. + + Expression_list* vals = new Expression_list(); + if (fntype->is_builtin()) + ; + else if (!is_method) + vals->push_back(fn); + else if (interface_method != NULL) + vals->push_back(interface_method->expr()); + else if (bound_method != NULL) + { + vals->push_back(bound_method->method()); + Expression* first_arg = bound_method->first_argument(); + + // We always pass a pointer when calling a method. + if (first_arg->type()->points_to() == NULL) + first_arg = Expression::make_unary(OPERATOR_AND, first_arg, location); + + // 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 = bound_method->first_argument_type(); + if (fatype != NULL) + { + if (fatype->points_to() == NULL) + fatype = Type::make_pointer_type(fatype); + Type* unsafe = Type::make_pointer_type(Type::make_void_type()); + first_arg = Expression::make_cast(unsafe, first_arg, location); + first_arg = Expression::make_cast(fatype, first_arg, location); + } + + vals->push_back(first_arg); + } + else + gcc_unreachable(); + + if (ce->args() != NULL) + { + for (Expression_list::const_iterator p = ce->args()->begin(); + p != ce->args()->end(); + ++p) + vals->push_back(*p); + } + + // Build the struct. + Expression* constructor = + Expression::make_struct_composite_literal(this->struct_type_, vals, + location); + + // Allocate the initialized struct on the heap. + constructor = Expression::make_heap_composite(constructor, location); + + // Look up the thunk. + Named_object* named_thunk = gogo->lookup(thunk_name, NULL); + gcc_assert(named_thunk != NULL && named_thunk->is_function()); + + // Build the call. + Expression* func = Expression::make_func_reference(named_thunk, NULL, + location); + Expression_list* params = new Expression_list(); + params->push_back(constructor); + Call_expression* call = Expression::make_call(func, params, false, location); + + // Build the simple go or defer statement. + Statement* s; + if (this->classification() == STATEMENT_GO) + s = Statement::make_go_statement(call, location); + else if (this->classification() == STATEMENT_DEFER) + s = Statement::make_defer_statement(call, location); + else + gcc_unreachable(); + + // The current block should end with the go statement. + gcc_assert(block->statements()->size() >= 1); + gcc_assert(block->statements()->back() == this); + block->replace_statement(block->statements()->size() - 1, s); + + // We already ran the determine_types pass, so we need to run it now + // for the new statement. + s->determine_types(); + + // Sanity check. + gogo->check_types_in_block(block); + + // Return true to tell the block not to keep looking at statements. + return true; +} + +// Set the name to use for thunk parameter N. + +void +Thunk_statement::thunk_field_param(int n, char* buf, size_t buflen) +{ + snprintf(buf, buflen, "a%d", n); +} + +// Build a new struct type to hold the parameters for a complicated +// thunk statement. FNTYPE is the type of the function call. + +Struct_type* +Thunk_statement::build_struct(Function_type* fntype) +{ + source_location location = this->location(); + + Struct_field_list* fields = new Struct_field_list(); + + Call_expression* ce = this->call_->call_expression(); + Expression* fn = ce->fn(); + + Interface_field_reference_expression* interface_method = + fn->interface_field_reference_expression(); + if (interface_method != NULL) + { + // If this thunk statement calls a method on an interface, we + // pass the interface object to the thunk. + Typed_identifier tid(Thunk_statement::thunk_field_fn, + interface_method->expr()->type(), + location); + fields->push_back(Struct_field(tid)); + } + else if (!fntype->is_builtin()) + { + // The function to call. + Typed_identifier tid(Go_statement::thunk_field_fn, fntype, location); + fields->push_back(Struct_field(tid)); + } + else if (ce->is_recover_call()) + { + // The predeclared recover function has no argument. However, + // we add an argument when building recover thunks. Handle that + // here. + fields->push_back(Struct_field(Typed_identifier("can_recover", + Type::lookup_bool_type(), + location))); + } + + if (fn->bound_method_expression() != NULL) + { + gcc_assert(fntype->is_method()); + Type* rtype = fntype->receiver()->type(); + // We always pass the receiver as a pointer. + if (rtype->points_to() == NULL) + rtype = Type::make_pointer_type(rtype); + Typed_identifier tid(Thunk_statement::thunk_field_receiver, rtype, + location); + fields->push_back(Struct_field(tid)); + } + + const Expression_list* args = ce->args(); + if (args != NULL) + { + int i = 0; + for (Expression_list::const_iterator p = args->begin(); + p != args->end(); + ++p, ++i) + { + char buf[50]; + this->thunk_field_param(i, buf, sizeof buf); + fields->push_back(Struct_field(Typed_identifier(buf, (*p)->type(), + location))); + } + } + + return Type::make_struct_type(fields, location); +} + +// Build the thunk we are going to call. This is a brand new, albeit +// artificial, function. + +void +Thunk_statement::build_thunk(Gogo* gogo, const std::string& thunk_name, + Function_type* fntype) +{ + source_location location = this->location(); + + Call_expression* ce = this->call_->call_expression(); + + bool may_call_recover = false; + if (this->classification() == STATEMENT_DEFER) + { + Func_expression* fn = ce->fn()->func_expression(); + if (fn == NULL) + may_call_recover = true; + else + { + const Named_object* no = fn->named_object(); + if (!no->is_function()) + may_call_recover = true; + else + may_call_recover = no->func_value()->calls_recover(); + } + } + + // Build the type of the thunk. The thunk takes a single parameter, + // which is a pointer to the special structure we build. + const char* const parameter_name = "__go_thunk_parameter"; + Typed_identifier_list* thunk_parameters = new Typed_identifier_list(); + Type* pointer_to_struct_type = Type::make_pointer_type(this->struct_type_); + thunk_parameters->push_back(Typed_identifier(parameter_name, + pointer_to_struct_type, + location)); + + Typed_identifier_list* thunk_results = NULL; + if (may_call_recover) + { + // When deferring a function which may call recover, add a + // return value, to disable tail call optimizations which will + // break the way we check whether recover is permitted. + thunk_results = new Typed_identifier_list(); + thunk_results->push_back(Typed_identifier("", Type::lookup_bool_type(), + location)); + } + + Function_type* thunk_type = Type::make_function_type(NULL, thunk_parameters, + thunk_results, + location); + + // Start building the thunk. + Named_object* function = gogo->start_function(thunk_name, thunk_type, true, + location); + + // For a defer statement, start with a call to + // __go_set_defer_retaddr. */ + Label* retaddr_label = NULL; + if (may_call_recover) + { + retaddr_label = gogo->add_label_reference("retaddr"); + Expression* arg = Expression::make_label_addr(retaddr_label, location); + Expression_list* args = new Expression_list(); + args->push_back(arg); + + static Named_object* set_defer_retaddr; + if (set_defer_retaddr == NULL) + { + const source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + Type *voidptr_type = Type::make_pointer_type(Type::make_void_type()); + param_types->push_back(Typed_identifier("r", voidptr_type, bloc)); + + Typed_identifier_list* result_types = new Typed_identifier_list(); + result_types->push_back(Typed_identifier("", + Type::lookup_bool_type(), + bloc)); + + Function_type* t = Type::make_function_type(NULL, param_types, + result_types, bloc); + set_defer_retaddr = + Named_object::make_function_declaration("__go_set_defer_retaddr", + NULL, t, bloc); + const char* n = "__go_set_defer_retaddr"; + set_defer_retaddr->func_declaration_value()->set_asm_name(n); + } + + Expression* fn = Expression::make_func_reference(set_defer_retaddr, + NULL, location); + Expression* call = Expression::make_call(fn, args, false, location); + + // This is a hack to prevent the middle-end from deleting the + // label. + gogo->start_block(location); + gogo->add_statement(Statement::make_goto_statement(retaddr_label, + location)); + Block* then_block = gogo->finish_block(location); + then_block->determine_types(); + + Statement* s = Statement::make_if_statement(call, then_block, NULL, + location); + s->determine_types(); + gogo->add_statement(s); + } + + // Get a reference to the parameter. + Named_object* named_parameter = gogo->lookup(parameter_name, NULL); + gcc_assert(named_parameter != NULL && named_parameter->is_variable()); + + // Build the call. Note that the field names are the same as the + // ones used in build_struct. + Expression* thunk_parameter = Expression::make_var_reference(named_parameter, + location); + thunk_parameter = Expression::make_unary(OPERATOR_MULT, thunk_parameter, + location); + + Bound_method_expression* bound_method = ce->fn()->bound_method_expression(); + Interface_field_reference_expression* interface_method = + ce->fn()->interface_field_reference_expression(); + + Expression* func_to_call; + unsigned int next_index; + if (!fntype->is_builtin()) + { + func_to_call = Expression::make_field_reference(thunk_parameter, + 0, location); + next_index = 1; + } + else + { + gcc_assert(bound_method == NULL && interface_method == NULL); + func_to_call = ce->fn(); + next_index = 0; + } + + if (bound_method != NULL) + { + Expression* r = Expression::make_field_reference(thunk_parameter, 1, + location); + // The main program passes in a function pointer from the + // interface expression, so here we can make a bound method in + // all cases. + func_to_call = Expression::make_bound_method(r, func_to_call, + location); + next_index = 2; + } + else if (interface_method != NULL) + { + // The main program passes the interface object. + const std::string& name(interface_method->name()); + func_to_call = Expression::make_interface_field_reference(func_to_call, + name, + location); + } + + Expression_list* call_params = new Expression_list(); + const Struct_field_list* fields = this->struct_type_->fields(); + Struct_field_list::const_iterator p = fields->begin(); + for (unsigned int i = 0; i < next_index; ++i) + ++p; + bool is_recover_call = ce->is_recover_call(); + Expression* recover_arg = NULL; + for (; p != fields->end(); ++p, ++next_index) + { + Expression* thunk_param = Expression::make_var_reference(named_parameter, + location); + thunk_param = Expression::make_unary(OPERATOR_MULT, thunk_param, + location); + Expression* param = Expression::make_field_reference(thunk_param, + next_index, + location); + if (!is_recover_call) + call_params->push_back(param); + else + { + gcc_assert(call_params->empty()); + recover_arg = param; + } + } + + if (call_params->empty()) + { + delete call_params; + call_params = NULL; + } + + Expression* call = Expression::make_call(func_to_call, call_params, false, + location); + // We need to lower in case this is a builtin function. + call = call->lower(gogo, function, -1); + Call_expression* call_ce = call->call_expression(); + if (call_ce != NULL && may_call_recover) + call_ce->set_is_deferred(); + + Statement* call_statement = Statement::make_statement(call); + + // We already ran the determine_types pass, so we need to run it + // just for this statement now. + call_statement->determine_types(); + + // Sanity check. + call->check_types(gogo); + + if (call_ce != NULL && recover_arg != NULL) + call_ce->set_recover_arg(recover_arg); + + gogo->add_statement(call_statement); + + // If this is a defer statement, the label comes immediately after + // the call. + if (may_call_recover) + { + gogo->add_label_definition("retaddr", location); + + Expression_list* vals = new Expression_list(); + vals->push_back(Expression::make_boolean(false, location)); + const Typed_identifier_list* results = + function->func_value()->type()->results(); + gogo->add_statement(Statement::make_return_statement(results, vals, + location)); + } + + // That is all the thunk has to do. + gogo->finish_function(location); +} + +// Get the function and argument trees. + +void +Thunk_statement::get_fn_and_arg(Translate_context* context, tree* pfn, + tree* parg) +{ + if (this->call_->is_error_expression()) + { + *pfn = error_mark_node; + *parg = error_mark_node; + return; + } + + Call_expression* ce = this->call_->call_expression(); + + Expression* fn = ce->fn(); + *pfn = fn->get_tree(context); + + const Expression_list* args = ce->args(); + if (args == NULL || args->empty()) + *parg = null_pointer_node; + else + { + gcc_assert(args->size() == 1); + *parg = args->front()->get_tree(context); + } +} + +// Class Go_statement. + +tree +Go_statement::do_get_tree(Translate_context* context) +{ + tree fn_tree; + tree arg_tree; + this->get_fn_and_arg(context, &fn_tree, &arg_tree); + + static tree go_fndecl; + + tree fn_arg_type = NULL_TREE; + if (go_fndecl == NULL_TREE) + { + // Only build FN_ARG_TYPE if we need it. + tree subargtypes = tree_cons(NULL_TREE, ptr_type_node, void_list_node); + tree subfntype = build_function_type(ptr_type_node, subargtypes); + fn_arg_type = build_pointer_type(subfntype); + } + + return Gogo::call_builtin(&go_fndecl, + this->location(), + "__go_go", + 2, + void_type_node, + fn_arg_type, + fn_tree, + ptr_type_node, + arg_tree); +} + +// Make a go statement. + +Statement* +Statement::make_go_statement(Call_expression* call, source_location location) +{ + return new Go_statement(call, location); +} + +// Class Defer_statement. + +tree +Defer_statement::do_get_tree(Translate_context* context) +{ + source_location loc = this->location(); + + tree fn_tree; + tree arg_tree; + this->get_fn_and_arg(context, &fn_tree, &arg_tree); + if (fn_tree == error_mark_node || arg_tree == error_mark_node) + return error_mark_node; + + static tree defer_fndecl; + + tree fn_arg_type = NULL_TREE; + if (defer_fndecl == NULL_TREE) + { + // Only build FN_ARG_TYPE if we need it. + tree subargtypes = tree_cons(NULL_TREE, ptr_type_node, void_list_node); + tree subfntype = build_function_type(ptr_type_node, subargtypes); + fn_arg_type = build_pointer_type(subfntype); + } + + tree defer_stack = context->function()->func_value()->defer_stack(loc); + + return Gogo::call_builtin(&defer_fndecl, + loc, + "__go_defer", + 3, + void_type_node, + ptr_type_node, + defer_stack, + fn_arg_type, + fn_tree, + ptr_type_node, + arg_tree); +} + +// Make a defer statement. + +Statement* +Statement::make_defer_statement(Call_expression* call, + source_location location) +{ + return new Defer_statement(call, location); +} + +// Class Return_statement. + +// Traverse assignments. We treat each return value as a top level +// RHS in an expression. + +bool +Return_statement::do_traverse_assignments(Traverse_assignments* tassign) +{ + Expression_list* vals = this->vals_; + if (vals != NULL) + { + for (Expression_list::iterator p = vals->begin(); + p != vals->end(); + ++p) + tassign->value(&*p, true, true); + } + return true; +} + +// Lower a return statement. If we are returning a function call +// which returns multiple values which match the current function, +// split up the call's results. If the function has named result +// variables, and the return statement lists explicit values, then +// implement it by assigning the values to the result variables and +// changing the statement to not list any values. This lets +// panic/recover work correctly. + +Statement* +Return_statement::do_lower(Gogo*, Block* enclosing) +{ + if (this->vals_ == NULL) + return this; + + const Typed_identifier_list* results = this->results_; + if (results == NULL || results->empty()) + return this; + + // If the current function has multiple return values, and we are + // returning a single call expression, split up the call expression. + size_t results_count = results->size(); + if (results_count > 1 + && this->vals_->size() == 1 + && this->vals_->front()->call_expression() != NULL) + { + Call_expression* call = this->vals_->front()->call_expression(); + size_t count = results->size(); + Expression_list* vals = new Expression_list; + for (size_t i = 0; i < count; ++i) + vals->push_back(Expression::make_call_result(call, i)); + delete this->vals_; + this->vals_ = vals; + } + + if (results->front().name().empty()) + return this; + + if (results_count != this->vals_->size()) + { + // Presumably an error which will be reported in check_types. + return this; + } + + // Assign to named return values and then return them. + + source_location loc = this->location(); + const Block* top = enclosing; + while (top->enclosing() != NULL) + top = top->enclosing(); + + const Bindings *bindings = top->bindings(); + Block* b = new Block(enclosing, loc); + + Expression_list* lhs = new Expression_list(); + Expression_list* rhs = new Expression_list(); + + Expression_list::const_iterator pe = this->vals_->begin(); + int i = 1; + for (Typed_identifier_list::const_iterator pr = results->begin(); + pr != results->end(); + ++pr, ++pe, ++i) + { + Named_object* rv = bindings->lookup_local(pr->name()); + if (rv == NULL || !rv->is_result_variable()) + { + // Presumably an error. + delete b; + delete lhs; + delete rhs; + return this; + } + + Expression* e = *pe; + + // Check types now so that we give a good error message. The + // result type is known. We determine the expression type + // early. + + Type *rvtype = rv->result_var_value()->type(); + Type_context type_context(rvtype, false); + e->determine_type(&type_context); + + std::string reason; + if (Type::are_assignable(rvtype, e->type(), &reason)) + { + Expression* ve = Expression::make_var_reference(rv, e->location()); + lhs->push_back(ve); + rhs->push_back(e); + } + else + { + if (reason.empty()) + error_at(e->location(), "incompatible type for return value %d", i); + else + error_at(e->location(), + "incompatible type for return value %d (%s)", + i, reason.c_str()); + } + } + gcc_assert(lhs->size() == rhs->size()); + + if (lhs->empty()) + ; + else if (lhs->size() == 1) + { + b->add_statement(Statement::make_assignment(lhs->front(), rhs->front(), + loc)); + delete lhs; + delete rhs; + } + else + b->add_statement(Statement::make_tuple_assignment(lhs, rhs, loc)); + + b->add_statement(Statement::make_return_statement(this->results_, NULL, + loc)); + + return Statement::make_block_statement(b, loc); +} + +// Determine types. + +void +Return_statement::do_determine_types() +{ + if (this->vals_ == NULL) + return; + const Typed_identifier_list* results = this->results_; + + Typed_identifier_list::const_iterator pt; + if (results != NULL) + pt = results->begin(); + for (Expression_list::iterator pe = this->vals_->begin(); + pe != this->vals_->end(); + ++pe) + { + if (results == NULL || pt == results->end()) + (*pe)->determine_type_no_context(); + else + { + Type_context context(pt->type(), false); + (*pe)->determine_type(&context); + ++pt; + } + } +} + +// Check types. + +void +Return_statement::do_check_types(Gogo*) +{ + if (this->vals_ == NULL) + return; + + const Typed_identifier_list* results = this->results_; + if (results == NULL) + { + this->report_error(_("return with value in function " + "with no return type")); + return; + } + + int i = 1; + Typed_identifier_list::const_iterator pt = results->begin(); + for (Expression_list::const_iterator pe = this->vals_->begin(); + pe != this->vals_->end(); + ++pe, ++pt, ++i) + { + if (pt == results->end()) + { + this->report_error(_("too many values in return statement")); + return; + } + std::string reason; + if (!Type::are_assignable(pt->type(), (*pe)->type(), &reason)) + { + if (reason.empty()) + error_at(this->location(), + "incompatible type for return value %d", + i); + else + error_at(this->location(), + "incompatible type for return value %d (%s)", + i, reason.c_str()); + this->set_is_error(); + } + else if (pt->type()->is_error_type() + || (*pe)->type()->is_error_type() + || pt->type()->is_undefined() + || (*pe)->type()->is_undefined()) + { + // Make sure we get the error for an undefined type. + pt->type()->base(); + (*pe)->type()->base(); + this->set_is_error(); + } + } + + if (pt != results->end()) + this->report_error(_("not enough values in return statement")); +} + +// Build a RETURN_EXPR tree. + +tree +Return_statement::do_get_tree(Translate_context* context) +{ + Function* function = context->function()->func_value(); + tree fndecl = function->get_decl(); + if (fndecl == error_mark_node || DECL_RESULT(fndecl) == error_mark_node) + return error_mark_node; + + const Typed_identifier_list* results = this->results_; + + if (this->vals_ == NULL) + { + tree stmt_list = NULL_TREE; + tree retval = function->return_value(context->gogo(), + context->function(), + this->location(), + &stmt_list); + tree set; + if (retval == NULL_TREE) + set = NULL_TREE; + else if (retval == error_mark_node) + return error_mark_node; + else + set = fold_build2_loc(this->location(), MODIFY_EXPR, void_type_node, + DECL_RESULT(fndecl), retval); + append_to_statement_list(this->build_stmt_1(RETURN_EXPR, set), + &stmt_list); + return stmt_list; + } + else if (this->vals_->size() == 1) + { + gcc_assert(!VOID_TYPE_P(TREE_TYPE(TREE_TYPE(fndecl)))); + tree val = (*this->vals_->begin())->get_tree(context); + gcc_assert(results != NULL && results->size() == 1); + val = Expression::convert_for_assignment(context, + results->begin()->type(), + (*this->vals_->begin())->type(), + val, this->location()); + if (val == error_mark_node) + return error_mark_node; + tree set = build2(MODIFY_EXPR, void_type_node, + DECL_RESULT(fndecl), val); + SET_EXPR_LOCATION(set, this->location()); + return this->build_stmt_1(RETURN_EXPR, set); + } + else + { + gcc_assert(!VOID_TYPE_P(TREE_TYPE(TREE_TYPE(fndecl)))); + tree stmt_list = NULL_TREE; + tree rettype = TREE_TYPE(DECL_RESULT(fndecl)); + tree retvar = create_tmp_var(rettype, "RESULT"); + gcc_assert(results != NULL && results->size() == this->vals_->size()); + Expression_list::const_iterator pv = this->vals_->begin(); + Typed_identifier_list::const_iterator pr = results->begin(); + for (tree field = TYPE_FIELDS(rettype); + field != NULL_TREE; + ++pv, ++pr, field = DECL_CHAIN(field)) + { + gcc_assert(pv != this->vals_->end()); + tree val = (*pv)->get_tree(context); + val = Expression::convert_for_assignment(context, pr->type(), + (*pv)->type(), val, + this->location()); + if (val == error_mark_node) + return error_mark_node; + tree set = build2(MODIFY_EXPR, void_type_node, + build3(COMPONENT_REF, TREE_TYPE(field), + retvar, field, NULL_TREE), + val); + SET_EXPR_LOCATION(set, this->location()); + append_to_statement_list(set, &stmt_list); + } + tree set = build2(MODIFY_EXPR, void_type_node, DECL_RESULT(fndecl), + retvar); + append_to_statement_list(this->build_stmt_1(RETURN_EXPR, set), + &stmt_list); + return stmt_list; + } +} + +// Make a return statement. + +Statement* +Statement::make_return_statement(const Typed_identifier_list* results, + Expression_list* vals, + source_location location) +{ + return new Return_statement(results, vals, location); +} + +// A break or continue statement. + +class Bc_statement : public Statement +{ + public: + Bc_statement(bool is_break, Unnamed_label* label, source_location location) + : Statement(STATEMENT_BREAK_OR_CONTINUE, location), + label_(label), is_break_(is_break) + { } + + bool + is_break() const + { return this->is_break_; } + + protected: + int + do_traverse(Traverse*) + { return TRAVERSE_CONTINUE; } + + bool + do_may_fall_through() const + { return false; } + + tree + do_get_tree(Translate_context*) + { return this->label_->get_goto(this->location()); } + + private: + // The label that this branches to. + Unnamed_label* label_; + // True if this is "break", false if it is "continue". + bool is_break_; +}; + +// Make a break statement. + +Statement* +Statement::make_break_statement(Unnamed_label* label, source_location location) +{ + return new Bc_statement(true, label, location); +} + +// Make a continue statement. + +Statement* +Statement::make_continue_statement(Unnamed_label* label, + source_location location) +{ + return new Bc_statement(false, label, location); +} + +// A goto statement. + +class Goto_statement : public Statement +{ + public: + Goto_statement(Label* label, source_location location) + : Statement(STATEMENT_GOTO, location), + label_(label) + { } + + protected: + int + do_traverse(Traverse*) + { return TRAVERSE_CONTINUE; } + + void + do_check_types(Gogo*); + + bool + do_may_fall_through() const + { return false; } + + tree + do_get_tree(Translate_context*); + + private: + Label* label_; +}; + +// Check types for a label. There aren't any types per se, but we use +// this to give an error if the label was never defined. + +void +Goto_statement::do_check_types(Gogo*) +{ + if (!this->label_->is_defined()) + { + error_at(this->location(), "reference to undefined label %qs", + Gogo::message_name(this->label_->name()).c_str()); + this->set_is_error(); + } +} + +// Return the tree for the goto statement. + +tree +Goto_statement::do_get_tree(Translate_context*) +{ + return this->build_stmt_1(GOTO_EXPR, this->label_->get_decl()); +} + +// Make a goto statement. + +Statement* +Statement::make_goto_statement(Label* label, source_location location) +{ + return new Goto_statement(label, location); +} + +// A goto statement to an unnamed label. + +class Goto_unnamed_statement : public Statement +{ + public: + Goto_unnamed_statement(Unnamed_label* label, source_location location) + : Statement(STATEMENT_GOTO_UNNAMED, location), + label_(label) + { } + + protected: + int + do_traverse(Traverse*) + { return TRAVERSE_CONTINUE; } + + bool + do_may_fall_through() const + { return false; } + + tree + do_get_tree(Translate_context*) + { return this->label_->get_goto(this->location()); } + + private: + Unnamed_label* label_; +}; + +// Make a goto statement to an unnamed label. + +Statement* +Statement::make_goto_unnamed_statement(Unnamed_label* label, + source_location location) +{ + return new Goto_unnamed_statement(label, location); +} + +// Class Label_statement. + +// Traversal. + +int +Label_statement::do_traverse(Traverse*) +{ + return TRAVERSE_CONTINUE; +} + +// Return a tree defining this label. + +tree +Label_statement::do_get_tree(Translate_context*) +{ + return this->build_stmt_1(LABEL_EXPR, this->label_->get_decl()); +} + +// Make a label statement. + +Statement* +Statement::make_label_statement(Label* label, source_location location) +{ + return new Label_statement(label, location); +} + +// An unnamed label statement. + +class Unnamed_label_statement : public Statement +{ + public: + Unnamed_label_statement(Unnamed_label* label) + : Statement(STATEMENT_UNNAMED_LABEL, label->location()), + label_(label) + { } + + protected: + int + do_traverse(Traverse*) + { return TRAVERSE_CONTINUE; } + + tree + do_get_tree(Translate_context*) + { return this->label_->get_definition(); } + + private: + // The label. + Unnamed_label* label_; +}; + +// Make an unnamed label statement. + +Statement* +Statement::make_unnamed_label_statement(Unnamed_label* label) +{ + return new Unnamed_label_statement(label); +} + +// An if statement. + +class If_statement : public Statement +{ + public: + If_statement(Expression* cond, Block* then_block, Block* else_block, + source_location location) + : Statement(STATEMENT_IF, location), + cond_(cond), then_block_(then_block), else_block_(else_block) + { } + + protected: + int + do_traverse(Traverse*); + + void + do_determine_types(); + + void + do_check_types(Gogo*); + + bool + do_may_fall_through() const; + + tree + do_get_tree(Translate_context*); + + private: + Expression* cond_; + Block* then_block_; + Block* else_block_; +}; + +// Traversal. + +int +If_statement::do_traverse(Traverse* traverse) +{ + if (this->cond_ != NULL) + { + if (this->traverse_expression(traverse, &this->cond_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->then_block_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->else_block_ != NULL) + { + if (this->else_block_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +void +If_statement::do_determine_types() +{ + if (this->cond_ != NULL) + { + Type_context context(Type::lookup_bool_type(), false); + this->cond_->determine_type(&context); + } + this->then_block_->determine_types(); + if (this->else_block_ != NULL) + this->else_block_->determine_types(); +} + +// Check types. + +void +If_statement::do_check_types(Gogo*) +{ + if (this->cond_ != NULL) + { + Type* type = this->cond_->type(); + if (type->is_error_type()) + this->set_is_error(); + else if (!type->is_boolean_type()) + this->report_error(_("expected boolean expression")); + } +} + +// Whether the overall statement may fall through. + +bool +If_statement::do_may_fall_through() const +{ + return (this->else_block_ == NULL + || this->then_block_->may_fall_through() + || this->else_block_->may_fall_through()); +} + +// Get tree. + +tree +If_statement::do_get_tree(Translate_context* context) +{ + gcc_assert(this->cond_ == NULL + || this->cond_->type()->is_boolean_type() + || this->cond_->type()->is_error_type()); + tree cond_tree = (this->cond_ == NULL + ? boolean_true_node + : this->cond_->get_tree(context)); + tree then_tree = this->then_block_->get_tree(context); + tree else_tree = (this->else_block_ == NULL + ? NULL_TREE + : this->else_block_->get_tree(context)); + if (cond_tree == error_mark_node + || then_tree == error_mark_node + || else_tree == error_mark_node) + return error_mark_node; + tree ret = build3(COND_EXPR, void_type_node, cond_tree, then_tree, + else_tree); + SET_EXPR_LOCATION(ret, this->location()); + return ret; +} + +// Make an if statement. + +Statement* +Statement::make_if_statement(Expression* cond, Block* then_block, + Block* else_block, source_location location) +{ + return new If_statement(cond, then_block, else_block, location); +} + +// Class Case_clauses::Case_clause. + +// Traversal. + +int +Case_clauses::Case_clause::traverse(Traverse* traverse) +{ + if (this->cases_ != NULL + && (traverse->traverse_mask() + & (Traverse::traverse_types | Traverse::traverse_expressions)) != 0) + { + if (this->cases_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->statements_ != NULL) + { + if (this->statements_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Check whether all the case expressions are integer constants. + +bool +Case_clauses::Case_clause::is_constant() const +{ + if (this->cases_ != NULL) + { + for (Expression_list::const_iterator p = this->cases_->begin(); + p != this->cases_->end(); + ++p) + if (!(*p)->is_constant() || (*p)->type()->integer_type() == NULL) + return false; + } + return true; +} + +// Lower a case clause for a nonconstant switch. VAL_TEMP is the +// value we are switching on; it may be NULL. If START_LABEL is not +// NULL, it goes at the start of the statements, after the condition +// test. We branch to FINISH_LABEL at the end of the statements. + +void +Case_clauses::Case_clause::lower(Block* b, Temporary_statement* val_temp, + Unnamed_label* start_label, + Unnamed_label* finish_label) const +{ + source_location loc = this->location_; + Unnamed_label* next_case_label; + if (this->cases_ == NULL || this->cases_->empty()) + { + gcc_assert(this->is_default_); + next_case_label = NULL; + } + else + { + Expression* cond = NULL; + + for (Expression_list::const_iterator p = this->cases_->begin(); + p != this->cases_->end(); + ++p) + { + Expression* this_cond; + if (val_temp == NULL) + this_cond = *p; + else + { + Expression* ref = Expression::make_temporary_reference(val_temp, + loc); + this_cond = Expression::make_binary(OPERATOR_EQEQ, ref, *p, loc); + } + + if (cond == NULL) + cond = this_cond; + else + cond = Expression::make_binary(OPERATOR_OROR, cond, this_cond, loc); + } + + Block* then_block = new Block(b, loc); + next_case_label = new Unnamed_label(UNKNOWN_LOCATION); + Statement* s = Statement::make_goto_unnamed_statement(next_case_label, + loc); + then_block->add_statement(s); + + // if !COND { goto NEXT_CASE_LABEL } + cond = Expression::make_unary(OPERATOR_NOT, cond, loc); + s = Statement::make_if_statement(cond, then_block, NULL, loc); + b->add_statement(s); + } + + if (start_label != NULL) + b->add_statement(Statement::make_unnamed_label_statement(start_label)); + + if (this->statements_ != NULL) + b->add_statement(Statement::make_block_statement(this->statements_, loc)); + + Statement* s = Statement::make_goto_unnamed_statement(finish_label, loc); + b->add_statement(s); + + if (next_case_label != NULL) + b->add_statement(Statement::make_unnamed_label_statement(next_case_label)); +} + +// Determine types. + +void +Case_clauses::Case_clause::determine_types(Type* type) +{ + if (this->cases_ != NULL) + { + Type_context case_context(type, false); + for (Expression_list::iterator p = this->cases_->begin(); + p != this->cases_->end(); + ++p) + (*p)->determine_type(&case_context); + } + if (this->statements_ != NULL) + this->statements_->determine_types(); +} + +// Check types. Returns false if there was an error. + +bool +Case_clauses::Case_clause::check_types(Type* type) +{ + if (this->cases_ != NULL) + { + for (Expression_list::iterator p = this->cases_->begin(); + p != this->cases_->end(); + ++p) + { + if (!Type::are_assignable(type, (*p)->type(), NULL) + && !Type::are_assignable((*p)->type(), type, NULL)) + { + error_at((*p)->location(), + "type mismatch between switch value and case clause"); + return false; + } + } + } + return true; +} + +// Return true if this clause may fall through to the following +// statements. Note that this is not the same as whether the case +// uses the "fallthrough" keyword. + +bool +Case_clauses::Case_clause::may_fall_through() const +{ + if (this->statements_ == NULL) + return true; + return this->statements_->may_fall_through(); +} + +// Build up the body of a SWITCH_EXPR. + +void +Case_clauses::Case_clause::get_constant_tree(Translate_context* context, + Unnamed_label* break_label, + Case_constants* case_constants, + tree* stmt_list) const +{ + if (this->cases_ != NULL) + { + for (Expression_list::const_iterator p = this->cases_->begin(); + p != this->cases_->end(); + ++p) + { + Type* itype; + mpz_t ival; + mpz_init(ival); + if (!(*p)->integer_constant_value(true, ival, &itype)) + { + // Something went wrong. This can happen with a + // negative constant and an unsigned switch value. + gcc_assert(saw_errors()); + continue; + } + gcc_assert(itype != NULL); + tree type_tree = itype->get_tree(context->gogo()); + tree val = Expression::integer_constant_tree(ival, type_tree); + mpz_clear(ival); + + if (val != error_mark_node) + { + gcc_assert(TREE_CODE(val) == INTEGER_CST); + + std::pair<Case_constants::iterator, bool> ins = + case_constants->insert(val); + if (!ins.second) + { + // Value was already present. + warning_at(this->location_, 0, + "duplicate case value will never match"); + continue; + } + + tree label = create_artificial_label(this->location_); + append_to_statement_list(build3(CASE_LABEL_EXPR, void_type_node, + val, NULL_TREE, label), + stmt_list); + } + } + } + + if (this->is_default_) + { + tree label = create_artificial_label(this->location_); + append_to_statement_list(build3(CASE_LABEL_EXPR, void_type_node, + NULL_TREE, NULL_TREE, label), + stmt_list); + } + + if (this->statements_ != NULL) + { + tree block_tree = this->statements_->get_tree(context); + if (block_tree != error_mark_node) + append_to_statement_list(block_tree, stmt_list); + } + + if (!this->is_fallthrough_) + append_to_statement_list(break_label->get_goto(this->location_), stmt_list); +} + +// Class Case_clauses. + +// Traversal. + +int +Case_clauses::traverse(Traverse* traverse) +{ + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (p->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Check whether all the case expressions are constant. + +bool +Case_clauses::is_constant() const +{ + for (Clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + if (!p->is_constant()) + return false; + return true; +} + +// Lower case clauses for a nonconstant switch. + +void +Case_clauses::lower(Block* b, Temporary_statement* val_temp, + Unnamed_label* break_label) const +{ + // The default case. + const Case_clause* default_case = NULL; + + // The label for the fallthrough of the previous case. + Unnamed_label* last_fallthrough_label = NULL; + + // The label for the start of the default case. This is used if the + // case before the default case falls through. + Unnamed_label* default_start_label = NULL; + + // The label for the end of the default case. This normally winds + // up as BREAK_LABEL, but it will be different if the default case + // falls through. + Unnamed_label* default_finish_label = NULL; + + for (Clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + // The label to use for the start of the statements for this + // case. This is NULL unless the previous case falls through. + Unnamed_label* start_label = last_fallthrough_label; + + // The label to jump to after the end of the statements for this + // case. + Unnamed_label* finish_label = break_label; + + last_fallthrough_label = NULL; + if (p->is_fallthrough() && p + 1 != this->clauses_.end()) + { + finish_label = new Unnamed_label(p->location()); + last_fallthrough_label = finish_label; + } + + if (!p->is_default()) + p->lower(b, val_temp, start_label, finish_label); + else + { + // We have to move the default case to the end, so that we + // only use it if all the other tests fail. + default_case = &*p; + default_start_label = start_label; + default_finish_label = finish_label; + } + } + + if (default_case != NULL) + default_case->lower(b, val_temp, default_start_label, + default_finish_label); + +} + +// Determine types. + +void +Case_clauses::determine_types(Type* type) +{ + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + p->determine_types(type); +} + +// Check types. Returns false if there was an error. + +bool +Case_clauses::check_types(Type* type) +{ + bool ret = true; + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (!p->check_types(type)) + ret = false; + } + return ret; +} + +// Return true if these clauses may fall through to the statements +// following the switch statement. + +bool +Case_clauses::may_fall_through() const +{ + bool found_default = false; + for (Clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (p->may_fall_through() && !p->is_fallthrough()) + return true; + if (p->is_default()) + found_default = true; + } + return !found_default; +} + +// Return a tree when all case expressions are constants. + +tree +Case_clauses::get_constant_tree(Translate_context* context, + Unnamed_label* break_label) const +{ + Case_constants case_constants; + tree stmt_list = NULL_TREE; + for (Clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + p->get_constant_tree(context, break_label, &case_constants, + &stmt_list); + return stmt_list; +} + +// A constant switch statement. A Switch_statement is lowered to this +// when all the cases are constants. + +class Constant_switch_statement : public Statement +{ + public: + Constant_switch_statement(Expression* val, Case_clauses* clauses, + Unnamed_label* break_label, + source_location location) + : Statement(STATEMENT_CONSTANT_SWITCH, location), + val_(val), clauses_(clauses), break_label_(break_label) + { } + + protected: + int + do_traverse(Traverse*); + + void + do_determine_types(); + + void + do_check_types(Gogo*); + + bool + do_may_fall_through() const; + + tree + do_get_tree(Translate_context*); + + private: + // The value to switch on. + Expression* val_; + // The case clauses. + Case_clauses* clauses_; + // The break label, if needed. + Unnamed_label* break_label_; +}; + +// Traversal. + +int +Constant_switch_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->clauses_->traverse(traverse); +} + +// Determine types. + +void +Constant_switch_statement::do_determine_types() +{ + this->val_->determine_type_no_context(); + this->clauses_->determine_types(this->val_->type()); +} + +// Check types. + +void +Constant_switch_statement::do_check_types(Gogo*) +{ + if (!this->clauses_->check_types(this->val_->type())) + 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. + +tree +Constant_switch_statement::do_get_tree(Translate_context* context) +{ + tree switch_val_tree = this->val_->get_tree(context); + + Unnamed_label* break_label = this->break_label_; + if (break_label == NULL) + break_label = new Unnamed_label(this->location()); + + tree stmt_list = NULL_TREE; + tree s = build3(SWITCH_EXPR, void_type_node, switch_val_tree, + this->clauses_->get_constant_tree(context, break_label), + NULL_TREE); + SET_EXPR_LOCATION(s, this->location()); + append_to_statement_list(s, &stmt_list); + + append_to_statement_list(break_label->get_definition(), &stmt_list); + + return stmt_list; +} + +// Class Switch_statement. + +// Traversal. + +int +Switch_statement::do_traverse(Traverse* traverse) +{ + if (this->val_ != NULL) + { + if (this->traverse_expression(traverse, &this->val_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return this->clauses_->traverse(traverse); +} + +// Lower a Switch_statement to a Constant_switch_statement or a series +// of if statements. + +Statement* +Switch_statement::do_lower(Gogo*, Block* enclosing) +{ + source_location loc = this->location(); + + if (this->val_ != NULL + && (this->val_->is_error_expression() + || this->val_->type()->is_error_type())) + return Statement::make_error_statement(loc); + + if (this->val_ != NULL + && this->val_->type()->integer_type() != NULL + && !this->clauses_->empty() + && this->clauses_->is_constant()) + return new Constant_switch_statement(this->val_, this->clauses_, + this->break_label_, loc); + + Block* b = new Block(enclosing, loc); + + if (this->clauses_->empty()) + { + Expression* val = this->val_; + if (val == NULL) + val = Expression::make_boolean(true, loc); + return Statement::make_statement(val); + } + + Temporary_statement* val_temp; + if (this->val_ == NULL) + val_temp = NULL; + else + { + // var val_temp VAL_TYPE = VAL + val_temp = Statement::make_temporary(NULL, this->val_, loc); + b->add_statement(val_temp); + } + + this->clauses_->lower(b, val_temp, this->break_label()); + + Statement* s = Statement::make_unnamed_label_statement(this->break_label_); + b->add_statement(s); + + return Statement::make_block_statement(b, loc); +} + +// Return the break label for this switch statement, creating it if +// necessary. + +Unnamed_label* +Switch_statement::break_label() +{ + if (this->break_label_ == NULL) + this->break_label_ = new Unnamed_label(this->location()); + return this->break_label_; +} + +// Make a switch statement. + +Switch_statement* +Statement::make_switch_statement(Expression* val, source_location location) +{ + return new Switch_statement(val, location); +} + +// Class Type_case_clauses::Type_case_clause. + +// Traversal. + +int +Type_case_clauses::Type_case_clause::traverse(Traverse* traverse) +{ + if (!this->is_default_ + && ((traverse->traverse_mask() + & (Traverse::traverse_types | Traverse::traverse_expressions)) != 0) + && Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->statements_ != NULL) + return this->statements_->traverse(traverse); + return TRAVERSE_CONTINUE; +} + +// Lower one clause in a type switch. Add statements to the block B. +// The type descriptor we are switching on is in DESCRIPTOR_TEMP. +// BREAK_LABEL is the label at the end of the type switch. +// *STMTS_LABEL, if not NULL, is a label to put at the start of the +// statements. + +void +Type_case_clauses::Type_case_clause::lower(Block* b, + Temporary_statement* descriptor_temp, + Unnamed_label* break_label, + Unnamed_label** stmts_label) const +{ + source_location loc = this->location_; + + Unnamed_label* next_case_label = NULL; + if (!this->is_default_) + { + Type* type = this->type_; + + Expression* cond; + // The language permits case nil, which is of course a constant + // rather than a type. It will appear here as an invalid + // forwarding type. + if (type->is_nil_constant_as_type()) + { + Expression* ref = + Expression::make_temporary_reference(descriptor_temp, loc); + cond = Expression::make_binary(OPERATOR_EQEQ, ref, + Expression::make_nil(loc), + loc); + } + else + { + Expression* func; + if (type->interface_type() == NULL) + { + // func ifacetypeeq(*descriptor, *descriptor) bool + static Named_object* ifacetypeeq; + if (ifacetypeeq == NULL) + { + const source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = + new Typed_identifier_list(); + Type* descriptor_type = Type::make_type_descriptor_ptr_type(); + param_types->push_back(Typed_identifier("a", descriptor_type, + bloc)); + param_types->push_back(Typed_identifier("b", descriptor_type, + bloc)); + Typed_identifier_list* ret_types = + new Typed_identifier_list(); + Type* bool_type = Type::lookup_bool_type(); + ret_types->push_back(Typed_identifier("", bool_type, bloc)); + Function_type* fntype = Type::make_function_type(NULL, + param_types, + ret_types, + bloc); + ifacetypeeq = + Named_object::make_function_declaration("ifacetypeeq", NULL, + fntype, bloc); + const char* n = "runtime.ifacetypeeq"; + ifacetypeeq->func_declaration_value()->set_asm_name(n); + } + + // ifacetypeeq(descriptor_temp, DESCRIPTOR) + func = Expression::make_func_reference(ifacetypeeq, NULL, loc); + } + else + { + // func ifaceI2Tp(*descriptor, *descriptor) bool + static Named_object* ifaceI2Tp; + if (ifaceI2Tp == NULL) + { + const source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = + new Typed_identifier_list(); + Type* descriptor_type = Type::make_type_descriptor_ptr_type(); + param_types->push_back(Typed_identifier("a", descriptor_type, + bloc)); + param_types->push_back(Typed_identifier("b", descriptor_type, + bloc)); + Typed_identifier_list* ret_types = + new Typed_identifier_list(); + Type* bool_type = Type::lookup_bool_type(); + ret_types->push_back(Typed_identifier("", bool_type, bloc)); + Function_type* fntype = Type::make_function_type(NULL, + param_types, + ret_types, + bloc); + ifaceI2Tp = + Named_object::make_function_declaration("ifaceI2Tp", NULL, + fntype, bloc); + const char* n = "runtime.ifaceI2Tp"; + ifaceI2Tp->func_declaration_value()->set_asm_name(n); + } + + // ifaceI2Tp(descriptor_temp, DESCRIPTOR) + func = Expression::make_func_reference(ifaceI2Tp, NULL, loc); + } + Expression_list* params = new Expression_list(); + params->push_back(Expression::make_type_descriptor(type, loc)); + Expression* ref = + Expression::make_temporary_reference(descriptor_temp, loc); + params->push_back(ref); + cond = Expression::make_call(func, params, false, loc); + } + + Unnamed_label* dest; + if (!this->is_fallthrough_) + { + // if !COND { goto NEXT_CASE_LABEL } + next_case_label = new Unnamed_label(UNKNOWN_LOCATION); + dest = next_case_label; + cond = Expression::make_unary(OPERATOR_NOT, cond, loc); + } + else + { + // if COND { goto STMTS_LABEL } + gcc_assert(stmts_label != NULL); + if (*stmts_label == NULL) + *stmts_label = new Unnamed_label(UNKNOWN_LOCATION); + dest = *stmts_label; + } + Block* then_block = new Block(b, loc); + Statement* s = Statement::make_goto_unnamed_statement(dest, loc); + then_block->add_statement(s); + s = Statement::make_if_statement(cond, then_block, NULL, loc); + b->add_statement(s); + } + + if (this->statements_ != NULL + || (!this->is_fallthrough_ + && stmts_label != NULL + && *stmts_label != NULL)) + { + gcc_assert(!this->is_fallthrough_); + if (stmts_label != NULL && *stmts_label != NULL) + { + gcc_assert(!this->is_default_); + if (this->statements_ != NULL) + (*stmts_label)->set_location(this->statements_->start_location()); + Statement* s = Statement::make_unnamed_label_statement(*stmts_label); + b->add_statement(s); + *stmts_label = NULL; + } + if (this->statements_ != NULL) + b->add_statement(Statement::make_block_statement(this->statements_, + loc)); + } + + if (this->is_fallthrough_) + gcc_assert(next_case_label == NULL); + else + { + source_location gloc = (this->statements_ == NULL + ? loc + : this->statements_->end_location()); + b->add_statement(Statement::make_goto_unnamed_statement(break_label, + gloc)); + if (next_case_label != NULL) + { + Statement* s = + Statement::make_unnamed_label_statement(next_case_label); + b->add_statement(s); + } + } +} + +// Class Type_case_clauses. + +// Traversal. + +int +Type_case_clauses::traverse(Traverse* traverse) +{ + for (Type_clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (p->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Check for duplicate types. + +void +Type_case_clauses::check_duplicates() const +{ + typedef Unordered_set_hash(const Type*, Type_hash_identical, + Type_identical) Types_seen; + Types_seen types_seen; + for (Type_clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + Type* t = p->type(); + if (t == NULL) + continue; + if (t->is_nil_constant_as_type()) + t = Type::make_nil_type(); + std::pair<Types_seen::iterator, bool> ins = types_seen.insert(t); + if (!ins.second) + error_at(p->location(), "duplicate type in switch"); + } +} + +// Lower the clauses in a type switch. Add statements to the block B. +// The type descriptor we are switching on is in DESCRIPTOR_TEMP. +// BREAK_LABEL is the label at the end of the type switch. + +void +Type_case_clauses::lower(Block* b, Temporary_statement* descriptor_temp, + Unnamed_label* break_label) const +{ + const Type_case_clause* default_case = NULL; + + Unnamed_label* stmts_label = NULL; + for (Type_clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (!p->is_default()) + p->lower(b, descriptor_temp, break_label, &stmts_label); + else + { + // We are generating a series of tests, which means that we + // need to move the default case to the end. + default_case = &*p; + } + } + gcc_assert(stmts_label == NULL); + + if (default_case != NULL) + default_case->lower(b, descriptor_temp, break_label, NULL); +} + +// Class Type_switch_statement. + +// Traversal. + +int +Type_switch_statement::do_traverse(Traverse* traverse) +{ + if (this->var_ == NULL) + { + if (this->traverse_expression(traverse, &this->expr_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->clauses_ != NULL) + return this->clauses_->traverse(traverse); + return TRAVERSE_CONTINUE; +} + +// Lower a type switch statement to a series of if statements. The gc +// compiler is able to generate a table in some cases. However, that +// does not work for us because we may have type descriptors in +// different shared libraries, so we can't compare them with simple +// equality testing. + +Statement* +Type_switch_statement::do_lower(Gogo*, Block* enclosing) +{ + const source_location loc = this->location(); + + if (this->clauses_ != NULL) + this->clauses_->check_duplicates(); + + Block* b = new Block(enclosing, loc); + + Type* val_type = (this->var_ != NULL + ? this->var_->var_value()->type() + : this->expr_->type()); + + // var descriptor_temp DESCRIPTOR_TYPE + Type* descriptor_type = Type::make_type_descriptor_ptr_type(); + Temporary_statement* descriptor_temp = + Statement::make_temporary(descriptor_type, NULL, loc); + b->add_statement(descriptor_temp); + + if (val_type->interface_type() == NULL) + { + // Doing a type switch on a non-interface type. Should we issue + // a warning for this case? + Expression* lhs = Expression::make_temporary_reference(descriptor_temp, + loc); + Expression* rhs; + if (val_type->is_nil_type()) + rhs = Expression::make_nil(loc); + else + { + if (val_type->is_abstract()) + val_type = val_type->make_non_abstract_type(); + rhs = Expression::make_type_descriptor(val_type, loc); + } + Statement* s = Statement::make_assignment(lhs, rhs, loc); + b->add_statement(s); + } + else + { + const source_location bloc = BUILTINS_LOCATION; + + // func {efacetype,ifacetype}(*interface) *descriptor + // FIXME: This should be inlined. + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("i", val_type, bloc)); + Typed_identifier_list* ret_types = new Typed_identifier_list(); + ret_types->push_back(Typed_identifier("", descriptor_type, bloc)); + Function_type* fntype = Type::make_function_type(NULL, param_types, + ret_types, bloc); + bool is_empty = val_type->interface_type()->is_empty(); + const char* fnname = is_empty ? "efacetype" : "ifacetype"; + Named_object* fn = + Named_object::make_function_declaration(fnname, NULL, fntype, bloc); + const char* asm_name = (is_empty + ? "runtime.efacetype" + : "runtime.ifacetype"); + fn->func_declaration_value()->set_asm_name(asm_name); + + // descriptor_temp = ifacetype(val_temp) + Expression* func = Expression::make_func_reference(fn, NULL, loc); + Expression_list* params = new Expression_list(); + Expression* ref; + if (this->var_ == NULL) + ref = this->expr_; + else + ref = Expression::make_var_reference(this->var_, loc); + params->push_back(ref); + Expression* call = Expression::make_call(func, params, false, loc); + Expression* lhs = Expression::make_temporary_reference(descriptor_temp, + loc); + Statement* s = Statement::make_assignment(lhs, call, loc); + b->add_statement(s); + } + + if (this->clauses_ != NULL) + this->clauses_->lower(b, descriptor_temp, this->break_label()); + + Statement* s = Statement::make_unnamed_label_statement(this->break_label_); + b->add_statement(s); + + return Statement::make_block_statement(b, loc); +} + +// Return the break label for this type switch statement, creating it +// if necessary. + +Unnamed_label* +Type_switch_statement::break_label() +{ + if (this->break_label_ == NULL) + this->break_label_ = new Unnamed_label(this->location()); + return this->break_label_; +} + +// Make a type switch statement. + +Type_switch_statement* +Statement::make_type_switch_statement(Named_object* var, Expression* expr, + source_location location) +{ + return new Type_switch_statement(var, expr, location); +} + +// Class Select_clauses::Select_clause. + +// Traversal. + +int +Select_clauses::Select_clause::traverse(Traverse* traverse) +{ + if (!this->is_lowered_ + && (traverse->traverse_mask() + & (Traverse::traverse_types | Traverse::traverse_expressions)) != 0) + { + if (this->channel_ != NULL) + { + if (Expression::traverse(&this->channel_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->val_ != NULL) + { + if (Expression::traverse(&this->val_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + } + if (this->statements_ != NULL) + { + if (this->statements_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Lowering. Here we pull out the channel and the send values, to +// enforce the order of evaluation. We also add explicit send and +// receive statements to the clauses. + +void +Select_clauses::Select_clause::lower(Block* b) +{ + if (this->is_default_) + { + gcc_assert(this->channel_ == NULL && this->val_ == NULL); + this->is_lowered_ = true; + return; + } + + source_location loc = this->location_; + + // Evaluate the channel before the select statement. + Temporary_statement* channel_temp = Statement::make_temporary(NULL, + this->channel_, + loc); + b->add_statement(channel_temp); + this->channel_ = Expression::make_temporary_reference(channel_temp, loc); + + // If this is a send clause, evaluate the value to send before the + // select statement. + Temporary_statement* val_temp = NULL; + if (this->is_send_) + { + val_temp = Statement::make_temporary(NULL, this->val_, loc); + b->add_statement(val_temp); + } + + // Add the send or receive before the rest of the statements if any. + Block *init = new Block(b, loc); + Expression* ref = Expression::make_temporary_reference(channel_temp, loc); + if (this->is_send_) + { + Expression* ref2 = Expression::make_temporary_reference(val_temp, loc); + Send_expression* send = Expression::make_send(ref, ref2, loc); + send->discarding_value(); + send->set_for_select(); + init->add_statement(Statement::make_statement(send)); + } + else + { + Receive_expression* recv = Expression::make_receive(ref, loc); + recv->set_for_select(); + if (this->val_ != NULL) + { + gcc_assert(this->var_ == NULL); + init->add_statement(Statement::make_assignment(this->val_, recv, + loc)); + } + else if (this->var_ != NULL) + { + this->var_->var_value()->set_init(recv); + this->var_->var_value()->clear_type_from_chan_element(); + } + else + { + recv->discarding_value(); + init->add_statement(Statement::make_statement(recv)); + } + } + + if (this->statements_ != NULL) + init->add_statement(Statement::make_block_statement(this->statements_, + loc)); + + this->statements_ = init; + + // Now all references should be handled through the statements, not + // through here. + this->is_lowered_ = true; + this->val_ = NULL; + this->var_ = NULL; +} + +// Determine types. + +void +Select_clauses::Select_clause::determine_types() +{ + gcc_assert(this->is_lowered_); + if (this->statements_ != NULL) + this->statements_->determine_types(); +} + +// Whether this clause may fall through to the statement which follows +// the overall select statement. + +bool +Select_clauses::Select_clause::may_fall_through() const +{ + if (this->statements_ == NULL) + return true; + return this->statements_->may_fall_through(); +} + +// Return a tree for the statements to execute. + +tree +Select_clauses::Select_clause::get_statements_tree(Translate_context* context) +{ + if (this->statements_ == NULL) + return NULL_TREE; + return this->statements_->get_tree(context); +} + +// Class Select_clauses. + +// Traversal. + +int +Select_clauses::traverse(Traverse* traverse) +{ + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (p->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Lowering. Here we pull out the channel and the send values, to +// enforce the order of evaluation. We also add explicit send and +// receive statements to the clauses. + +void +Select_clauses::lower(Block* b) +{ + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + p->lower(b); +} + +// Determine types. + +void +Select_clauses::determine_types() +{ + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + p->determine_types(); +} + +// Return whether these select clauses fall through to the statement +// following the overall select statement. + +bool +Select_clauses::may_fall_through() const +{ + for (Clauses::const_iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + if (p->may_fall_through()) + return true; + return false; +} + +// Return a tree. We build a call to +// size_t __go_select(size_t count, _Bool has_default, +// channel* channels, _Bool* is_send) +// +// There are COUNT entries in the CHANNELS and IS_SEND arrays. The +// value in the IS_SEND array is true for send, false for receive. +// __go_select returns an integer from 0 to COUNT, inclusive. A +// return of 0 means that the default case should be run; this only +// happens if HAS_DEFAULT is non-zero. Otherwise the number indicates +// the case to run. + +// FIXME: This doesn't handle channels which send interface types +// where the receiver has a static type which matches that interface. + +tree +Select_clauses::get_tree(Translate_context* context, + Unnamed_label *break_label, + source_location location) +{ + size_t count = this->clauses_.size(); + VEC(constructor_elt, gc)* chan_init = VEC_alloc(constructor_elt, gc, count); + VEC(constructor_elt, gc)* is_send_init = VEC_alloc(constructor_elt, gc, + count); + Select_clause* default_clause = NULL; + tree final_stmt_list = NULL_TREE; + tree channel_type_tree = NULL_TREE; + + size_t i = 0; + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (p->is_default()) + { + default_clause = &*p; + --count; + continue; + } + + if (p->channel()->type()->channel_type() == NULL) + { + // We should have given an error in the send or receive + // statement we created via lowering. + gcc_assert(saw_errors()); + return error_mark_node; + } + + tree channel_tree = p->channel()->get_tree(context); + if (channel_tree == error_mark_node) + return error_mark_node; + channel_type_tree = TREE_TYPE(channel_tree); + + constructor_elt* elt = VEC_quick_push(constructor_elt, chan_init, NULL); + elt->index = build_int_cstu(sizetype, i); + elt->value = channel_tree; + + elt = VEC_quick_push(constructor_elt, is_send_init, NULL); + elt->index = build_int_cstu(sizetype, i); + elt->value = p->is_send() ? boolean_true_node : boolean_false_node; + + ++i; + } + gcc_assert(i == count); + + if (i == 0 && default_clause != NULL) + { + // There is only a default clause. + gcc_assert(final_stmt_list == NULL_TREE); + tree stmt_list = NULL_TREE; + append_to_statement_list(default_clause->get_statements_tree(context), + &stmt_list); + append_to_statement_list(break_label->get_definition(), &stmt_list); + return stmt_list; + } + + tree pointer_chan_type_tree = (channel_type_tree == NULL_TREE + ? ptr_type_node + : build_pointer_type(channel_type_tree)); + tree chans_arg; + tree pointer_boolean_type_tree = build_pointer_type(boolean_type_node); + tree is_sends_arg; + + if (i == 0) + { + chans_arg = fold_convert_loc(location, pointer_chan_type_tree, + null_pointer_node); + is_sends_arg = fold_convert_loc(location, pointer_boolean_type_tree, + null_pointer_node); + } + else + { + tree index_type_tree = build_index_type(size_int(count - 1)); + tree chan_array_type_tree = build_array_type(channel_type_tree, + index_type_tree); + tree chan_constructor = build_constructor(chan_array_type_tree, + chan_init); + tree chan_var = create_tmp_var(chan_array_type_tree, "CHAN"); + DECL_IGNORED_P(chan_var) = 0; + DECL_INITIAL(chan_var) = chan_constructor; + DECL_SOURCE_LOCATION(chan_var) = location; + TREE_ADDRESSABLE(chan_var) = 1; + tree decl_expr = build1(DECL_EXPR, void_type_node, chan_var); + SET_EXPR_LOCATION(decl_expr, location); + append_to_statement_list(decl_expr, &final_stmt_list); + + tree is_send_array_type_tree = build_array_type(boolean_type_node, + index_type_tree); + tree is_send_constructor = build_constructor(is_send_array_type_tree, + is_send_init); + tree is_send_var = create_tmp_var(is_send_array_type_tree, "ISSEND"); + DECL_IGNORED_P(is_send_var) = 0; + DECL_INITIAL(is_send_var) = is_send_constructor; + DECL_SOURCE_LOCATION(is_send_var) = location; + TREE_ADDRESSABLE(is_send_var) = 1; + decl_expr = build1(DECL_EXPR, void_type_node, is_send_var); + SET_EXPR_LOCATION(decl_expr, location); + append_to_statement_list(decl_expr, &final_stmt_list); + + chans_arg = fold_convert_loc(location, pointer_chan_type_tree, + build_fold_addr_expr_loc(location, + chan_var)); + is_sends_arg = fold_convert_loc(location, pointer_boolean_type_tree, + build_fold_addr_expr_loc(location, + is_send_var)); + } + + static tree select_fndecl; + tree call = Gogo::call_builtin(&select_fndecl, + location, + "__go_select", + 4, + sizetype, + sizetype, + size_int(count), + boolean_type_node, + (default_clause == NULL + ? boolean_false_node + : boolean_true_node), + pointer_chan_type_tree, + chans_arg, + pointer_boolean_type_tree, + is_sends_arg); + if (call == error_mark_node) + return error_mark_node; + + tree stmt_list = NULL_TREE; + + if (default_clause != NULL) + this->add_clause_tree(context, 0, default_clause, break_label, &stmt_list); + + i = 1; + for (Clauses::iterator p = this->clauses_.begin(); + p != this->clauses_.end(); + ++p) + { + if (!p->is_default()) + { + this->add_clause_tree(context, i, &*p, break_label, &stmt_list); + ++i; + } + } + + append_to_statement_list(break_label->get_definition(), &stmt_list); + + tree switch_stmt = build3(SWITCH_EXPR, sizetype, call, stmt_list, NULL_TREE); + SET_EXPR_LOCATION(switch_stmt, location); + append_to_statement_list(switch_stmt, &final_stmt_list); + + return final_stmt_list; +} + +// Add the tree for CLAUSE to STMT_LIST. + +void +Select_clauses::add_clause_tree(Translate_context* context, int case_index, + Select_clause* clause, + Unnamed_label* bottom_label, tree* stmt_list) +{ + tree label = create_artificial_label(clause->location()); + append_to_statement_list(build3(CASE_LABEL_EXPR, void_type_node, + build_int_cst(sizetype, case_index), + NULL_TREE, label), + stmt_list); + append_to_statement_list(clause->get_statements_tree(context), stmt_list); + tree g = bottom_label->get_goto(clause->statements() == NULL + ? clause->location() + : clause->statements()->end_location()); + append_to_statement_list(g, stmt_list); +} + +// Class Select_statement. + +// Return the break label for this switch statement, creating it if +// necessary. + +Unnamed_label* +Select_statement::break_label() +{ + if (this->break_label_ == NULL) + this->break_label_ = new Unnamed_label(this->location()); + return this->break_label_; +} + +// Lower a select statement. This will still return a select +// statement, but it will be modified to implement the order of +// evaluation rules, and to include the send and receive statements as +// explicit statements in the clauses. + +Statement* +Select_statement::do_lower(Gogo*, Block* enclosing) +{ + if (this->is_lowered_) + return this; + Block* b = new Block(enclosing, this->location()); + this->clauses_->lower(b); + this->is_lowered_ = true; + b->add_statement(this); + return Statement::make_block_statement(b, this->location()); +} + +// Return the tree for a select statement. + +tree +Select_statement::do_get_tree(Translate_context* context) +{ + return this->clauses_->get_tree(context, this->break_label(), + this->location()); +} + +// Make a select statement. + +Select_statement* +Statement::make_select_statement(source_location location) +{ + return new Select_statement(location); +} + +// Class For_statement. + +// Traversal. + +int +For_statement::do_traverse(Traverse* traverse) +{ + if (this->init_ != NULL) + { + if (this->init_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->cond_ != NULL) + { + if (this->traverse_expression(traverse, &this->cond_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->post_ != NULL) + { + if (this->post_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return this->statements_->traverse(traverse); +} + +// Lower a For_statement into if statements and gotos. Getting rid of +// complex statements make it easier to handle garbage collection. + +Statement* +For_statement::do_lower(Gogo*, Block* enclosing) +{ + Statement* s; + source_location loc = this->location(); + + Block* b = new Block(enclosing, this->location()); + if (this->init_ != NULL) + { + s = Statement::make_block_statement(this->init_, + this->init_->start_location()); + b->add_statement(s); + } + + Unnamed_label* entry = NULL; + if (this->cond_ != NULL) + { + entry = new Unnamed_label(this->location()); + b->add_statement(Statement::make_goto_unnamed_statement(entry, loc)); + } + + Unnamed_label* top = new Unnamed_label(this->location()); + b->add_statement(Statement::make_unnamed_label_statement(top)); + + s = Statement::make_block_statement(this->statements_, + this->statements_->start_location()); + b->add_statement(s); + + source_location end_loc = this->statements_->end_location(); + + Unnamed_label* cont = this->continue_label_; + if (cont != NULL) + b->add_statement(Statement::make_unnamed_label_statement(cont)); + + if (this->post_ != NULL) + { + s = Statement::make_block_statement(this->post_, + this->post_->start_location()); + b->add_statement(s); + end_loc = this->post_->end_location(); + } + + if (this->cond_ == NULL) + b->add_statement(Statement::make_goto_unnamed_statement(top, end_loc)); + else + { + b->add_statement(Statement::make_unnamed_label_statement(entry)); + + source_location cond_loc = this->cond_->location(); + Block* then_block = new Block(b, cond_loc); + s = Statement::make_goto_unnamed_statement(top, cond_loc); + then_block->add_statement(s); + + s = Statement::make_if_statement(this->cond_, then_block, NULL, cond_loc); + b->add_statement(s); + } + + Unnamed_label* brk = this->break_label_; + if (brk != NULL) + b->add_statement(Statement::make_unnamed_label_statement(brk)); + + b->set_end_location(end_loc); + + return Statement::make_block_statement(b, loc); +} + +// Return the break label, creating it if necessary. + +Unnamed_label* +For_statement::break_label() +{ + if (this->break_label_ == NULL) + this->break_label_ = new Unnamed_label(this->location()); + return this->break_label_; +} + +// Return the continue LABEL_EXPR. + +Unnamed_label* +For_statement::continue_label() +{ + if (this->continue_label_ == NULL) + this->continue_label_ = new Unnamed_label(this->location()); + return this->continue_label_; +} + +// Set the break and continue labels a for statement. This is used +// when lowering a for range statement. + +void +For_statement::set_break_continue_labels(Unnamed_label* break_label, + Unnamed_label* continue_label) +{ + gcc_assert(this->break_label_ == NULL && this->continue_label_ == NULL); + this->break_label_ = break_label; + this->continue_label_ = continue_label; +} + +// Make a for statement. + +For_statement* +Statement::make_for_statement(Block* init, Expression* cond, Block* post, + source_location location) +{ + return new For_statement(init, cond, post, location); +} + +// Class For_range_statement. + +// Traversal. + +int +For_range_statement::do_traverse(Traverse* traverse) +{ + if (this->traverse_expression(traverse, &this->index_var_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->value_var_ != NULL) + { + if (this->traverse_expression(traverse, &this->value_var_) + == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->traverse_expression(traverse, &this->range_) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return this->statements_->traverse(traverse); +} + +// Lower a for range statement. For simplicity we lower this into a +// for statement, which will then be lowered in turn to goto +// statements. + +Statement* +For_range_statement::do_lower(Gogo* gogo, Block* enclosing) +{ + Type* range_type = this->range_->type(); + if (range_type->points_to() != NULL + && range_type->points_to()->array_type() != NULL + && !range_type->points_to()->is_open_array_type()) + range_type = range_type->points_to(); + + Type* index_type; + Type* value_type = NULL; + if (range_type->array_type() != NULL) + { + index_type = Type::lookup_integer_type("int"); + value_type = range_type->array_type()->element_type(); + } + else if (range_type->is_string_type()) + { + index_type = Type::lookup_integer_type("int"); + value_type = index_type; + } + else if (range_type->map_type() != NULL) + { + index_type = range_type->map_type()->key_type(); + value_type = range_type->map_type()->val_type(); + } + else if (range_type->channel_type() != NULL) + { + index_type = range_type->channel_type()->element_type(); + if (this->value_var_ != NULL) + { + if (!this->value_var_->type()->is_error_type()) + this->report_error(_("too many variables for range clause " + "with channel")); + return Statement::make_error_statement(this->location()); + } + } + else + { + this->report_error(_("range clause must have " + "array, slice, setring, map, or channel type")); + return Statement::make_error_statement(this->location()); + } + + source_location loc = this->location(); + Block* temp_block = new Block(enclosing, loc); + + Named_object* range_object = NULL; + Temporary_statement* range_temp = NULL; + Var_expression* ve = this->range_->var_expression(); + if (ve != NULL) + range_object = ve->named_object(); + else + { + range_temp = Statement::make_temporary(NULL, this->range_, loc); + temp_block->add_statement(range_temp); + } + + Temporary_statement* index_temp = Statement::make_temporary(index_type, + NULL, loc); + temp_block->add_statement(index_temp); + + Temporary_statement* value_temp = NULL; + if (this->value_var_ != NULL) + { + value_temp = Statement::make_temporary(value_type, NULL, loc); + temp_block->add_statement(value_temp); + } + + Block* body = new Block(temp_block, loc); + + Block* init; + Expression* cond; + Block* iter_init; + Block* post; + + // Arrange to do a loop appropriate for the type. We will produce + // for INIT ; COND ; POST { + // ITER_INIT + // INDEX = INDEX_TEMP + // VALUE = VALUE_TEMP // If there is a value + // original statements + // } + + if (range_type->array_type() != NULL) + this->lower_range_array(gogo, temp_block, body, range_object, range_temp, + index_temp, value_temp, &init, &cond, &iter_init, + &post); + else if (range_type->is_string_type()) + this->lower_range_string(gogo, temp_block, body, range_object, range_temp, + index_temp, value_temp, &init, &cond, &iter_init, + &post); + else if (range_type->map_type() != NULL) + this->lower_range_map(gogo, temp_block, body, range_object, range_temp, + index_temp, value_temp, &init, &cond, &iter_init, + &post); + else if (range_type->channel_type() != NULL) + this->lower_range_channel(gogo, temp_block, body, range_object, range_temp, + index_temp, value_temp, &init, &cond, &iter_init, + &post); + else + gcc_unreachable(); + + if (iter_init != NULL) + body->add_statement(Statement::make_block_statement(iter_init, loc)); + + Statement* assign; + Expression* index_ref = Expression::make_temporary_reference(index_temp, loc); + if (this->value_var_ == NULL) + { + assign = Statement::make_assignment(this->index_var_, index_ref, loc); + } + else + { + Expression_list* lhs = new Expression_list(); + lhs->push_back(this->index_var_); + lhs->push_back(this->value_var_); + + Expression_list* rhs = new Expression_list(); + rhs->push_back(index_ref); + rhs->push_back(Expression::make_temporary_reference(value_temp, loc)); + + assign = Statement::make_tuple_assignment(lhs, rhs, loc); + } + body->add_statement(assign); + + body->add_statement(Statement::make_block_statement(this->statements_, loc)); + + body->set_end_location(this->statements_->end_location()); + + For_statement* loop = Statement::make_for_statement(init, cond, post, + this->location()); + loop->add_statements(body); + loop->set_break_continue_labels(this->break_label_, this->continue_label_); + + temp_block->add_statement(loop); + + return Statement::make_block_statement(temp_block, loc); +} + +// Return a reference to the range, which may be in RANGE_OBJECT or in +// RANGE_TEMP. + +Expression* +For_range_statement::make_range_ref(Named_object* range_object, + Temporary_statement* range_temp, + source_location loc) +{ + if (range_object != NULL) + return Expression::make_var_reference(range_object, loc); + else + return Expression::make_temporary_reference(range_temp, loc); +} + +// Return a call to the predeclared function FUNCNAME passing a +// reference to the temporary variable ARG. + +Expression* +For_range_statement::call_builtin(Gogo* gogo, const char* funcname, + Expression* arg, + source_location loc) +{ + Named_object* no = gogo->lookup_global(funcname); + gcc_assert(no != NULL && no->is_function_declaration()); + Expression* func = Expression::make_func_reference(no, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(arg); + return Expression::make_call(func, params, false, loc); +} + +// Lower a for range over an array or slice. + +void +For_range_statement::lower_range_array(Gogo* gogo, + Block* enclosing, + Block* body_block, + Named_object* range_object, + Temporary_statement* range_temp, + Temporary_statement* index_temp, + Temporary_statement* value_temp, + Block** pinit, + Expression** pcond, + Block** piter_init, + Block** ppost) +{ + source_location loc = this->location(); + + // The loop we generate: + // len_temp := len(range) + // for index_temp = 0; index_temp < len_temp; index_temp++ { + // value_temp = range[index_temp] + // index = index_temp + // value = value_temp + // original body + // } + + // Set *PINIT to + // var len_temp int + // len_temp = len(range) + // index_temp = 0 + + Block* init = new Block(enclosing, loc); + + Expression* ref = this->make_range_ref(range_object, range_temp, loc); + Expression* len_call = this->call_builtin(gogo, "len", ref, loc); + Temporary_statement* len_temp = Statement::make_temporary(index_temp->type(), + len_call, loc); + init->add_statement(len_temp); + + mpz_t zval; + mpz_init_set_ui(zval, 0UL); + Expression* zexpr = Expression::make_integer(&zval, NULL, loc); + mpz_clear(zval); + + ref = Expression::make_temporary_reference(index_temp, loc); + Statement* s = Statement::make_assignment(ref, zexpr, loc); + init->add_statement(s); + + *pinit = init; + + // Set *PCOND to + // index_temp < len_temp + + ref = Expression::make_temporary_reference(index_temp, loc); + Expression* ref2 = Expression::make_temporary_reference(len_temp, loc); + Expression* lt = Expression::make_binary(OPERATOR_LT, ref, ref2, loc); + + *pcond = lt; + + // Set *PITER_INIT to + // value_temp = range[index_temp] + + Block* iter_init = NULL; + if (value_temp != NULL) + { + iter_init = new Block(body_block, loc); + + ref = this->make_range_ref(range_object, range_temp, loc); + Expression* ref2 = Expression::make_temporary_reference(index_temp, loc); + Expression* index = Expression::make_index(ref, ref2, NULL, loc); + + ref = Expression::make_temporary_reference(value_temp, loc); + s = Statement::make_assignment(ref, index, loc); + + iter_init->add_statement(s); + } + *piter_init = iter_init; + + // Set *PPOST to + // index_temp++ + + Block* post = new Block(enclosing, loc); + ref = Expression::make_temporary_reference(index_temp, loc); + s = Statement::make_inc_statement(ref); + post->add_statement(s); + *ppost = post; +} + +// Lower a for range over a string. + +void +For_range_statement::lower_range_string(Gogo* gogo, + Block* enclosing, + Block* body_block, + Named_object* range_object, + Temporary_statement* range_temp, + Temporary_statement* index_temp, + Temporary_statement* value_temp, + Block** pinit, + Expression** pcond, + Block** piter_init, + Block** ppost) +{ + source_location loc = this->location(); + + // The loop we generate: + // var next_index_temp int + // for index_temp = 0; ; index_temp = next_index_temp { + // next_index_temp, value_temp = stringiter2(range, index_temp) + // if next_index_temp == 0 { + // break + // } + // index = index_temp + // value = value_temp + // original body + // } + + // Set *PINIT to + // var next_index_temp int + // index_temp = 0 + + Block* init = new Block(enclosing, loc); + + Temporary_statement* next_index_temp = + Statement::make_temporary(index_temp->type(), NULL, loc); + init->add_statement(next_index_temp); + + mpz_t zval; + mpz_init_set_ui(zval, 0UL); + Expression* zexpr = Expression::make_integer(&zval, NULL, loc); + + Expression* ref = Expression::make_temporary_reference(index_temp, loc); + Statement* s = Statement::make_assignment(ref, zexpr, loc); + + init->add_statement(s); + *pinit = init; + + // The loop has no condition. + + *pcond = NULL; + + // Set *PITER_INIT to + // next_index_temp = runtime.stringiter(range, index_temp) + // or + // next_index_temp, value_temp = runtime.stringiter2(range, index_temp) + // followed by + // if next_index_temp == 0 { + // break + // } + + Block* iter_init = new Block(body_block, loc); + + Named_object* no; + if (value_temp == NULL) + { + static Named_object* stringiter; + if (stringiter == NULL) + { + source_location bloc = BUILTINS_LOCATION; + Type* int_type = gogo->lookup_global("int")->type_value(); + + Typed_identifier_list* params = new Typed_identifier_list(); + params->push_back(Typed_identifier("s", Type::make_string_type(), + bloc)); + params->push_back(Typed_identifier("k", int_type, bloc)); + + Typed_identifier_list* results = new Typed_identifier_list(); + results->push_back(Typed_identifier("", int_type, bloc)); + + Function_type* fntype = Type::make_function_type(NULL, params, + results, bloc); + stringiter = Named_object::make_function_declaration("stringiter", + NULL, fntype, + bloc); + const char* n = "runtime.stringiter"; + stringiter->func_declaration_value()->set_asm_name(n); + } + no = stringiter; + } + else + { + static Named_object* stringiter2; + if (stringiter2 == NULL) + { + source_location bloc = BUILTINS_LOCATION; + Type* int_type = gogo->lookup_global("int")->type_value(); + + Typed_identifier_list* params = new Typed_identifier_list(); + params->push_back(Typed_identifier("s", Type::make_string_type(), + bloc)); + params->push_back(Typed_identifier("k", int_type, bloc)); + + Typed_identifier_list* results = new Typed_identifier_list(); + results->push_back(Typed_identifier("", int_type, bloc)); + results->push_back(Typed_identifier("", int_type, bloc)); + + Function_type* fntype = Type::make_function_type(NULL, params, + results, bloc); + stringiter2 = Named_object::make_function_declaration("stringiter", + NULL, fntype, + bloc); + const char* n = "runtime.stringiter2"; + stringiter2->func_declaration_value()->set_asm_name(n); + } + no = stringiter2; + } + + Expression* func = Expression::make_func_reference(no, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(this->make_range_ref(range_object, range_temp, loc)); + params->push_back(Expression::make_temporary_reference(index_temp, loc)); + Call_expression* call = Expression::make_call(func, params, false, loc); + + if (value_temp == NULL) + { + ref = Expression::make_temporary_reference(next_index_temp, loc); + s = Statement::make_assignment(ref, call, loc); + } + else + { + Expression_list* lhs = new Expression_list(); + lhs->push_back(Expression::make_temporary_reference(next_index_temp, + loc)); + lhs->push_back(Expression::make_temporary_reference(value_temp, loc)); + + Expression_list* rhs = new Expression_list(); + rhs->push_back(Expression::make_call_result(call, 0)); + rhs->push_back(Expression::make_call_result(call, 1)); + + s = Statement::make_tuple_assignment(lhs, rhs, loc); + } + iter_init->add_statement(s); + + ref = Expression::make_temporary_reference(next_index_temp, loc); + zexpr = Expression::make_integer(&zval, NULL, loc); + mpz_clear(zval); + Expression* equals = Expression::make_binary(OPERATOR_EQEQ, ref, zexpr, loc); + + Block* then_block = new Block(iter_init, loc); + s = Statement::make_break_statement(this->break_label(), loc); + then_block->add_statement(s); + + s = Statement::make_if_statement(equals, then_block, NULL, loc); + iter_init->add_statement(s); + + *piter_init = iter_init; + + // Set *PPOST to + // index_temp = next_index_temp + + Block* post = new Block(enclosing, loc); + + Expression* lhs = Expression::make_temporary_reference(index_temp, loc); + Expression* rhs = Expression::make_temporary_reference(next_index_temp, loc); + s = Statement::make_assignment(lhs, rhs, loc); + + post->add_statement(s); + *ppost = post; +} + +// Lower a for range over a map. + +void +For_range_statement::lower_range_map(Gogo* gogo, + Block* enclosing, + Block* body_block, + Named_object* range_object, + Temporary_statement* range_temp, + Temporary_statement* index_temp, + Temporary_statement* value_temp, + Block** pinit, + Expression** pcond, + Block** piter_init, + Block** ppost) +{ + source_location loc = this->location(); + + // The runtime uses a struct to handle ranges over a map. The + // struct is four pointers long. The first pointer is NULL when we + // have completed the iteration. + + // The loop we generate: + // var hiter map_iteration_struct + // for mapiterinit(range, &hiter); hiter[0] != nil; mapiternext(&hiter) { + // mapiter2(hiter, &index_temp, &value_temp) + // index = index_temp + // value = value_temp + // original body + // } + + // Set *PINIT to + // var hiter map_iteration_struct + // runtime.mapiterinit(range, &hiter) + + Block* init = new Block(enclosing, loc); + + const unsigned long map_iteration_size = 4; + + mpz_t ival; + mpz_init_set_ui(ival, map_iteration_size); + Expression* iexpr = Expression::make_integer(&ival, NULL, loc); + mpz_clear(ival); + + Type* byte_type = gogo->lookup_global("byte")->type_value(); + Type* ptr_type = Type::make_pointer_type(byte_type); + + Type* map_iteration_type = Type::make_array_type(ptr_type, iexpr); + Type* map_iteration_ptr = Type::make_pointer_type(map_iteration_type); + + Temporary_statement* hiter = Statement::make_temporary(map_iteration_type, + NULL, loc); + init->add_statement(hiter); + + source_location bloc = BUILTINS_LOCATION; + Typed_identifier_list* param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("map", this->range_->type(), bloc)); + param_types->push_back(Typed_identifier("it", map_iteration_ptr, bloc)); + Function_type* fntype = Type::make_function_type(NULL, param_types, NULL, + bloc); + + Named_object* mapiterinit = + Named_object::make_function_declaration("mapiterinit", NULL, fntype, bloc); + const char* n = "runtime.mapiterinit"; + mapiterinit->func_declaration_value()->set_asm_name(n); + + Expression* func = Expression::make_func_reference(mapiterinit, NULL, loc); + Expression_list* params = new Expression_list(); + params->push_back(this->make_range_ref(range_object, range_temp, loc)); + Expression* ref = Expression::make_temporary_reference(hiter, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + Expression* call = Expression::make_call(func, params, false, loc); + init->add_statement(Statement::make_statement(call)); + + *pinit = init; + + // Set *PCOND to + // hiter[0] != nil + + ref = Expression::make_temporary_reference(hiter, loc); + + mpz_t zval; + mpz_init_set_ui(zval, 0UL); + Expression* zexpr = Expression::make_integer(&zval, NULL, loc); + mpz_clear(zval); + + Expression* index = Expression::make_index(ref, zexpr, NULL, loc); + + Expression* ne = Expression::make_binary(OPERATOR_NOTEQ, index, + Expression::make_nil(loc), + loc); + + *pcond = ne; + + // Set *PITER_INIT to + // mapiter1(hiter, &index_temp) + // or + // mapiter2(hiter, &index_temp, &value_temp) + + Block* iter_init = new Block(body_block, loc); + + param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("hiter", map_iteration_ptr, bloc)); + Type* pkey_type = Type::make_pointer_type(index_temp->type()); + param_types->push_back(Typed_identifier("key", pkey_type, bloc)); + if (value_temp != NULL) + { + Type* pval_type = Type::make_pointer_type(value_temp->type()); + param_types->push_back(Typed_identifier("val", pval_type, bloc)); + } + fntype = Type::make_function_type(NULL, param_types, NULL, bloc); + n = value_temp == NULL ? "mapiter1" : "mapiter2"; + Named_object* mapiter = Named_object::make_function_declaration(n, NULL, + fntype, bloc); + n = value_temp == NULL ? "runtime.mapiter1" : "runtime.mapiter2"; + mapiter->func_declaration_value()->set_asm_name(n); + + func = Expression::make_func_reference(mapiter, NULL, loc); + params = new Expression_list(); + ref = Expression::make_temporary_reference(hiter, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + ref = Expression::make_temporary_reference(index_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + if (value_temp != NULL) + { + ref = Expression::make_temporary_reference(value_temp, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + } + call = Expression::make_call(func, params, false, loc); + iter_init->add_statement(Statement::make_statement(call)); + + *piter_init = iter_init; + + // Set *PPOST to + // mapiternext(&hiter) + + Block* post = new Block(enclosing, loc); + + static Named_object* mapiternext; + if (mapiternext == NULL) + { + param_types = new Typed_identifier_list(); + param_types->push_back(Typed_identifier("it", map_iteration_ptr, bloc)); + fntype = Type::make_function_type(NULL, param_types, NULL, bloc); + mapiternext = Named_object::make_function_declaration("mapiternext", + NULL, fntype, + bloc); + const char* n = "runtime.mapiternext"; + mapiternext->func_declaration_value()->set_asm_name(n); + } + + func = Expression::make_func_reference(mapiternext, NULL, loc); + params = new Expression_list(); + ref = Expression::make_temporary_reference(hiter, loc); + params->push_back(Expression::make_unary(OPERATOR_AND, ref, loc)); + call = Expression::make_call(func, params, false, loc); + post->add_statement(Statement::make_statement(call)); + + *ppost = post; +} + +// Lower a for range over a channel. + +void +For_range_statement::lower_range_channel(Gogo* gogo, + Block*, + Block* body_block, + Named_object* range_object, + Temporary_statement* range_temp, + Temporary_statement* index_temp, + Temporary_statement* value_temp, + Block** pinit, + Expression** pcond, + Block** piter_init, + Block** ppost) +{ + gcc_assert(value_temp == NULL); + + source_location loc = this->location(); + + // The loop we generate: + // for { + // index_temp = <-range + // if closed(range) { + // break + // } + // index = index_temp + // value = value_temp + // original body + // } + + // We have no initialization code, no condition, and no post code. + + *pinit = NULL; + *pcond = NULL; + *ppost = NULL; + + // Set *PITER_INIT to + // index_temp = <-range + // if closed(range) { + // break + // } + + Block* iter_init = new Block(body_block, loc); + + Expression* ref = this->make_range_ref(range_object, range_temp, loc); + Expression* cond = this->call_builtin(gogo, "closed", ref, loc); + + ref = this->make_range_ref(range_object, range_temp, loc); + Expression* recv = Expression::make_receive(ref, loc); + ref = Expression::make_temporary_reference(index_temp, loc); + Statement* s = Statement::make_assignment(ref, recv, loc); + iter_init->add_statement(s); + + Block* then_block = new Block(iter_init, loc); + s = Statement::make_break_statement(this->break_label(), loc); + then_block->add_statement(s); + + s = Statement::make_if_statement(cond, then_block, NULL, loc); + iter_init->add_statement(s); + + *piter_init = iter_init; +} + +// Return the break LABEL_EXPR. + +Unnamed_label* +For_range_statement::break_label() +{ + if (this->break_label_ == NULL) + this->break_label_ = new Unnamed_label(this->location()); + return this->break_label_; +} + +// Return the continue LABEL_EXPR. + +Unnamed_label* +For_range_statement::continue_label() +{ + if (this->continue_label_ == NULL) + this->continue_label_ = new Unnamed_label(this->location()); + return this->continue_label_; +} + +// Make a for statement with a range clause. + +For_range_statement* +Statement::make_for_range_statement(Expression* index_var, + Expression* value_var, + Expression* range, + source_location location) +{ + return new For_range_statement(index_var, value_var, range, location); +} |