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Diffstat (limited to 'gcc-4.9/gcc/go/gofrontend/expressions.cc')
| -rw-r--r-- | gcc-4.9/gcc/go/gofrontend/expressions.cc | 15900 |
1 files changed, 15900 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/go/gofrontend/expressions.cc b/gcc-4.9/gcc/go/gofrontend/expressions.cc new file mode 100644 index 000000000..643a233ba --- /dev/null +++ b/gcc-4.9/gcc/go/gofrontend/expressions.cc @@ -0,0 +1,15900 @@ +// expressions.cc -- Go frontend expression handling. + +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "go-system.h" + +#include <algorithm> + +#include "toplev.h" +#include "intl.h" +#include "tree.h" +#include "stringpool.h" +#include "stor-layout.h" +#include "gimple-expr.h" +#include "tree-iterator.h" +#include "convert.h" +#include "real.h" +#include "realmpfr.h" + +#include "go-c.h" +#include "gogo.h" +#include "types.h" +#include "export.h" +#include "import.h" +#include "statements.h" +#include "lex.h" +#include "runtime.h" +#include "backend.h" +#include "expressions.h" +#include "ast-dump.h" + +// Class Expression. + +Expression::Expression(Expression_classification classification, + Location location) + : classification_(classification), location_(location) +{ +} + +Expression::~Expression() +{ +} + +// Traverse the expressions. + +int +Expression::traverse(Expression** pexpr, Traverse* traverse) +{ + Expression* expr = *pexpr; + if ((traverse->traverse_mask() & Traverse::traverse_expressions) != 0) + { + int t = traverse->expression(pexpr); + if (t == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + else if (t == TRAVERSE_SKIP_COMPONENTS) + return TRAVERSE_CONTINUE; + } + return expr->do_traverse(traverse); +} + +// Traverse subexpressions of this expression. + +int +Expression::traverse_subexpressions(Traverse* traverse) +{ + return this->do_traverse(traverse); +} + +// Default implementation for do_traverse for child classes. + +int +Expression::do_traverse(Traverse*) +{ + return TRAVERSE_CONTINUE; +} + +// This virtual function is called by the parser if the value of this +// expression is being discarded. By default, we give an error. +// Expressions with side effects override. + +bool +Expression::do_discarding_value() +{ + this->unused_value_error(); + return false; +} + +// This virtual function is called to export expressions. This will +// only be used by expressions which may be constant. + +void +Expression::do_export(Export*) const +{ + go_unreachable(); +} + +// Give an error saying that the value of the expression is not used. + +void +Expression::unused_value_error() +{ + this->report_error(_("value computed is not used")); +} + +// Note that this expression is an error. This is called by children +// when they discover an error. + +void +Expression::set_is_error() +{ + this->classification_ = EXPRESSION_ERROR; +} + +// For children to call to report an error conveniently. + +void +Expression::report_error(const char* msg) +{ + error_at(this->location_, "%s", msg); + this->set_is_error(); +} + +// Set types of variables and constants. This is implemented by the +// child class. + +void +Expression::determine_type(const Type_context* context) +{ + this->do_determine_type(context); +} + +// Set types when there is no context. + +void +Expression::determine_type_no_context() +{ + Type_context context; + this->do_determine_type(&context); +} + +// Return a tree handling any conversions which must be done during +// assignment. + +tree +Expression::convert_for_assignment(Translate_context* context, Type* lhs_type, + Type* rhs_type, tree rhs_tree, + Location location) +{ + if (lhs_type->is_error() || rhs_type->is_error()) + return error_mark_node; + + if (rhs_tree == error_mark_node || TREE_TYPE(rhs_tree) == error_mark_node) + return error_mark_node; + + Gogo* gogo = context->gogo(); + + tree lhs_type_tree = type_to_tree(lhs_type->get_backend(gogo)); + if (lhs_type_tree == error_mark_node) + return error_mark_node; + + if (lhs_type->forwarded() != rhs_type->forwarded() + && lhs_type->interface_type() != NULL) + { + if (rhs_type->interface_type() == NULL) + return Expression::convert_type_to_interface(context, lhs_type, + rhs_type, rhs_tree, + location); + else + return Expression::convert_interface_to_interface(context, lhs_type, + rhs_type, rhs_tree, + false, location); + } + else if (lhs_type->forwarded() != rhs_type->forwarded() + && rhs_type->interface_type() != NULL) + return Expression::convert_interface_to_type(context, lhs_type, rhs_type, + rhs_tree, location); + else if (lhs_type->is_slice_type() && rhs_type->is_nil_type()) + { + // Assigning nil to an open array. + go_assert(TREE_CODE(lhs_type_tree) == RECORD_TYPE); + + vec<constructor_elt, va_gc> *init; + vec_alloc(init, 3); + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = init->quick_push(empty); + tree field = TYPE_FIELDS(lhs_type_tree); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), + "__values") == 0); + elt->index = field; + elt->value = fold_convert(TREE_TYPE(field), null_pointer_node); + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), + "__count") == 0); + elt->index = field; + elt->value = fold_convert(TREE_TYPE(field), integer_zero_node); + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), + "__capacity") == 0); + elt->index = field; + elt->value = fold_convert(TREE_TYPE(field), integer_zero_node); + + tree val = build_constructor(lhs_type_tree, init); + TREE_CONSTANT(val) = 1; + + return val; + } + else if (rhs_type->is_nil_type()) + { + // The left hand side should be a pointer type at the tree + // level. + go_assert(POINTER_TYPE_P(lhs_type_tree)); + return fold_convert(lhs_type_tree, null_pointer_node); + } + else if (lhs_type_tree == TREE_TYPE(rhs_tree)) + { + // No conversion is needed. + return rhs_tree; + } + else if (POINTER_TYPE_P(lhs_type_tree) + || INTEGRAL_TYPE_P(lhs_type_tree) + || SCALAR_FLOAT_TYPE_P(lhs_type_tree) + || COMPLEX_FLOAT_TYPE_P(lhs_type_tree)) + return fold_convert_loc(location.gcc_location(), lhs_type_tree, rhs_tree); + else if ((TREE_CODE(lhs_type_tree) == RECORD_TYPE + && TREE_CODE(TREE_TYPE(rhs_tree)) == RECORD_TYPE) + || (TREE_CODE(lhs_type_tree) == ARRAY_TYPE + && TREE_CODE(TREE_TYPE(rhs_tree)) == ARRAY_TYPE)) + { + // Avoid confusion from zero sized variables which may be + // represented as non-zero-sized. + if (int_size_in_bytes(lhs_type_tree) == 0 + || int_size_in_bytes(TREE_TYPE(rhs_tree)) == 0) + return rhs_tree; + + // This conversion must be permitted by Go, or we wouldn't have + // gotten here. + go_assert(int_size_in_bytes(lhs_type_tree) + == int_size_in_bytes(TREE_TYPE(rhs_tree))); + return fold_build1_loc(location.gcc_location(), VIEW_CONVERT_EXPR, + lhs_type_tree, rhs_tree); + } + else + { + go_assert(useless_type_conversion_p(lhs_type_tree, TREE_TYPE(rhs_tree))); + return rhs_tree; + } +} + +// Return a tree for a conversion from a non-interface type to an +// interface type. + +tree +Expression::convert_type_to_interface(Translate_context* context, + Type* lhs_type, Type* rhs_type, + tree rhs_tree, Location location) +{ + Gogo* gogo = context->gogo(); + Interface_type* lhs_interface_type = lhs_type->interface_type(); + bool lhs_is_empty = lhs_interface_type->is_empty(); + + // Since RHS_TYPE is a static type, we can create the interface + // method table at compile time. + + // When setting an interface to nil, we just set both fields to + // NULL. + if (rhs_type->is_nil_type()) + { + Btype* lhs_btype = lhs_type->get_backend(gogo); + return expr_to_tree(gogo->backend()->zero_expression(lhs_btype)); + } + + // This should have been checked already. + go_assert(lhs_interface_type->implements_interface(rhs_type, NULL)); + + tree lhs_type_tree = type_to_tree(lhs_type->get_backend(gogo)); + if (lhs_type_tree == error_mark_node) + return error_mark_node; + + // An interface is a tuple. If LHS_TYPE is an empty interface type, + // then the first field is the type descriptor for RHS_TYPE. + // Otherwise it is the interface method table for RHS_TYPE. + tree first_field_value; + if (lhs_is_empty) + { + Bexpression* rhs_bexpr = + rhs_type->type_descriptor_pointer(gogo, location); + first_field_value = expr_to_tree(rhs_bexpr); + } + else + { + // Build the interface method table for this interface and this + // object type: a list of function pointers for each interface + // method. + Named_type* rhs_named_type = rhs_type->named_type(); + Struct_type* rhs_struct_type = rhs_type->struct_type(); + bool is_pointer = false; + if (rhs_named_type == NULL && rhs_struct_type == NULL) + { + rhs_named_type = rhs_type->deref()->named_type(); + rhs_struct_type = rhs_type->deref()->struct_type(); + is_pointer = true; + } + tree method_table; + if (rhs_named_type != NULL) + method_table = + rhs_named_type->interface_method_table(gogo, lhs_interface_type, + is_pointer); + else if (rhs_struct_type != NULL) + method_table = + rhs_struct_type->interface_method_table(gogo, lhs_interface_type, + is_pointer); + else + method_table = null_pointer_node; + first_field_value = fold_convert_loc(location.gcc_location(), + const_ptr_type_node, method_table); + } + if (first_field_value == error_mark_node) + return error_mark_node; + + // Start building a constructor for the value we will return. + + vec<constructor_elt, va_gc> *init; + vec_alloc(init, 2); + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = init->quick_push(empty); + tree field = TYPE_FIELDS(lhs_type_tree); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), + (lhs_is_empty ? "__type_descriptor" : "__methods")) == 0); + elt->index = field; + elt->value = fold_convert_loc(location.gcc_location(), TREE_TYPE(field), + first_field_value); + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__object") == 0); + elt->index = field; + + if (rhs_type->points_to() != NULL) + { + // We are assigning a pointer to the interface; the interface + // holds the pointer itself. + elt->value = rhs_tree; + return build_constructor(lhs_type_tree, init); + } + + // We are assigning a non-pointer value to the interface; the + // interface gets a copy of the value in the heap. + + tree object_size = TYPE_SIZE_UNIT(TREE_TYPE(rhs_tree)); + + tree space = gogo->allocate_memory(rhs_type, object_size, location); + space = fold_convert_loc(location.gcc_location(), + build_pointer_type(TREE_TYPE(rhs_tree)), space); + space = save_expr(space); + + tree ref = build_fold_indirect_ref_loc(location.gcc_location(), space); + TREE_THIS_NOTRAP(ref) = 1; + tree set = fold_build2_loc(location.gcc_location(), MODIFY_EXPR, + void_type_node, ref, rhs_tree); + + elt->value = fold_convert_loc(location.gcc_location(), TREE_TYPE(field), + space); + + return build2(COMPOUND_EXPR, lhs_type_tree, set, + build_constructor(lhs_type_tree, init)); +} + +// Return a tree for the type descriptor of RHS_TREE, which has +// interface type RHS_TYPE. If RHS_TREE is nil the result will be +// NULL. + +tree +Expression::get_interface_type_descriptor(Translate_context*, + Type* rhs_type, tree rhs_tree, + Location location) +{ + tree rhs_type_tree = TREE_TYPE(rhs_tree); + go_assert(TREE_CODE(rhs_type_tree) == RECORD_TYPE); + tree rhs_field = TYPE_FIELDS(rhs_type_tree); + tree v = build3(COMPONENT_REF, TREE_TYPE(rhs_field), rhs_tree, rhs_field, + NULL_TREE); + if (rhs_type->interface_type()->is_empty()) + { + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(rhs_field)), + "__type_descriptor") == 0); + return v; + } + + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(rhs_field)), "__methods") + == 0); + go_assert(POINTER_TYPE_P(TREE_TYPE(v))); + v = save_expr(v); + tree v1 = build_fold_indirect_ref_loc(location.gcc_location(), v); + go_assert(TREE_CODE(TREE_TYPE(v1)) == RECORD_TYPE); + tree f = TYPE_FIELDS(TREE_TYPE(v1)); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(f)), "__type_descriptor") + == 0); + v1 = build3(COMPONENT_REF, TREE_TYPE(f), v1, f, NULL_TREE); + + tree eq = fold_build2_loc(location.gcc_location(), EQ_EXPR, boolean_type_node, + v, fold_convert_loc(location.gcc_location(), + TREE_TYPE(v), + null_pointer_node)); + tree n = fold_convert_loc(location.gcc_location(), TREE_TYPE(v1), + null_pointer_node); + return fold_build3_loc(location.gcc_location(), COND_EXPR, TREE_TYPE(v1), + eq, n, v1); +} + +// Return a tree for the conversion of an interface type to an +// interface type. + +tree +Expression::convert_interface_to_interface(Translate_context* context, + Type *lhs_type, Type *rhs_type, + tree rhs_tree, bool for_type_guard, + Location location) +{ + Gogo* gogo = context->gogo(); + Interface_type* lhs_interface_type = lhs_type->interface_type(); + bool lhs_is_empty = lhs_interface_type->is_empty(); + + tree lhs_type_tree = type_to_tree(lhs_type->get_backend(gogo)); + if (lhs_type_tree == error_mark_node) + return error_mark_node; + + // In the general case this requires runtime examination of the type + // method table to match it up with the interface methods. + + // FIXME: If all of the methods in the right hand side interface + // also appear in the left hand side interface, then we don't need + // to do a runtime check, although we still need to build a new + // method table. + + // Get the type descriptor for the right hand side. This will be + // NULL for a nil interface. + + if (!DECL_P(rhs_tree)) + rhs_tree = save_expr(rhs_tree); + + tree rhs_type_descriptor = + Expression::get_interface_type_descriptor(context, rhs_type, rhs_tree, + location); + + // The result is going to be a two element constructor. + + vec<constructor_elt, va_gc> *init; + vec_alloc (init, 2); + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = init->quick_push(empty); + tree field = TYPE_FIELDS(lhs_type_tree); + elt->index = field; + + if (for_type_guard) + { + // A type assertion fails when converting a nil interface. + Bexpression* lhs_type_expr = lhs_type->type_descriptor_pointer(gogo, + location); + tree lhs_type_descriptor = expr_to_tree(lhs_type_expr); + static tree assert_interface_decl; + tree call = Gogo::call_builtin(&assert_interface_decl, + location, + "__go_assert_interface", + 2, + ptr_type_node, + TREE_TYPE(lhs_type_descriptor), + lhs_type_descriptor, + TREE_TYPE(rhs_type_descriptor), + rhs_type_descriptor); + if (call == error_mark_node) + return error_mark_node; + // This will panic if the interface conversion fails. + TREE_NOTHROW(assert_interface_decl) = 0; + elt->value = fold_convert_loc(location.gcc_location(), TREE_TYPE(field), + call); + } + else if (lhs_is_empty) + { + // A convertion to an empty interface always succeeds, and the + // first field is just the type descriptor of the object. + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), + "__type_descriptor") == 0); + elt->value = fold_convert_loc(location.gcc_location(), + TREE_TYPE(field), rhs_type_descriptor); + } + else + { + // A conversion to a non-empty interface may fail, but unlike a + // type assertion converting nil will always succeed. + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__methods") + == 0); + Bexpression* lhs_type_expr = lhs_type->type_descriptor_pointer(gogo, + location); + tree lhs_type_descriptor = expr_to_tree(lhs_type_expr); + + static tree convert_interface_decl; + tree call = Gogo::call_builtin(&convert_interface_decl, + location, + "__go_convert_interface", + 2, + ptr_type_node, + TREE_TYPE(lhs_type_descriptor), + lhs_type_descriptor, + TREE_TYPE(rhs_type_descriptor), + rhs_type_descriptor); + if (call == error_mark_node) + return error_mark_node; + // This will panic if the interface conversion fails. + TREE_NOTHROW(convert_interface_decl) = 0; + elt->value = fold_convert_loc(location.gcc_location(), TREE_TYPE(field), + call); + } + + // The second field is simply the object pointer. + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__object") == 0); + elt->index = field; + + tree rhs_type_tree = TREE_TYPE(rhs_tree); + go_assert(TREE_CODE(rhs_type_tree) == RECORD_TYPE); + tree rhs_field = DECL_CHAIN(TYPE_FIELDS(rhs_type_tree)); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(rhs_field)), "__object") == 0); + elt->value = build3(COMPONENT_REF, TREE_TYPE(rhs_field), rhs_tree, rhs_field, + NULL_TREE); + + return build_constructor(lhs_type_tree, init); +} + +// Return a tree for the conversion of an interface type to a +// non-interface type. + +tree +Expression::convert_interface_to_type(Translate_context* context, + Type *lhs_type, Type* rhs_type, + tree rhs_tree, Location location) +{ + Gogo* gogo = context->gogo(); + tree rhs_type_tree = TREE_TYPE(rhs_tree); + + tree lhs_type_tree = type_to_tree(lhs_type->get_backend(gogo)); + if (lhs_type_tree == error_mark_node) + return error_mark_node; + + // Call a function to check that the type is valid. The function + // will panic with an appropriate runtime type error if the type is + // not valid. + Bexpression* lhs_type_expr = lhs_type->type_descriptor_pointer(gogo, + location); + tree lhs_type_descriptor = expr_to_tree(lhs_type_expr); + + if (!DECL_P(rhs_tree)) + rhs_tree = save_expr(rhs_tree); + + tree rhs_type_descriptor = + Expression::get_interface_type_descriptor(context, rhs_type, rhs_tree, + location); + + Bexpression* rhs_inter_expr = rhs_type->type_descriptor_pointer(gogo, + location); + tree rhs_inter_descriptor = expr_to_tree(rhs_inter_expr); + + static tree check_interface_type_decl; + tree call = Gogo::call_builtin(&check_interface_type_decl, + location, + "__go_check_interface_type", + 3, + void_type_node, + TREE_TYPE(lhs_type_descriptor), + lhs_type_descriptor, + TREE_TYPE(rhs_type_descriptor), + rhs_type_descriptor, + TREE_TYPE(rhs_inter_descriptor), + rhs_inter_descriptor); + if (call == error_mark_node) + return error_mark_node; + // This call will panic if the conversion is invalid. + TREE_NOTHROW(check_interface_type_decl) = 0; + + // If the call succeeds, pull out the value. + go_assert(TREE_CODE(rhs_type_tree) == RECORD_TYPE); + tree rhs_field = DECL_CHAIN(TYPE_FIELDS(rhs_type_tree)); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(rhs_field)), "__object") == 0); + tree val = build3(COMPONENT_REF, TREE_TYPE(rhs_field), rhs_tree, rhs_field, + NULL_TREE); + + // If the value is a pointer, then it is the value we want. + // Otherwise it points to the value. + if (lhs_type->points_to() == NULL) + { + val = fold_convert_loc(location.gcc_location(), + build_pointer_type(lhs_type_tree), val); + val = build_fold_indirect_ref_loc(location.gcc_location(), val); + } + + return build2(COMPOUND_EXPR, lhs_type_tree, call, + fold_convert_loc(location.gcc_location(), lhs_type_tree, val)); +} + +// Convert an expression to a tree. This is implemented by the child +// class. Not that it is not in general safe to call this multiple +// times for a single expression, but that we don't catch such errors. + +tree +Expression::get_tree(Translate_context* context) +{ + // The child may have marked this expression as having an error. + if (this->classification_ == EXPRESSION_ERROR) + return error_mark_node; + + return this->do_get_tree(context); +} + +// Return a backend expression for VAL. +Bexpression* +Expression::backend_numeric_constant_expression(Translate_context* context, + Numeric_constant* val) +{ + Gogo* gogo = context->gogo(); + Type* type = val->type(); + if (type == NULL) + return gogo->backend()->error_expression(); + + Btype* btype = type->get_backend(gogo); + Bexpression* ret; + if (type->integer_type() != NULL) + { + mpz_t ival; + if (!val->to_int(&ival)) + { + go_assert(saw_errors()); + return gogo->backend()->error_expression(); + } + ret = gogo->backend()->integer_constant_expression(btype, ival); + mpz_clear(ival); + } + else if (type->float_type() != NULL) + { + mpfr_t fval; + if (!val->to_float(&fval)) + { + go_assert(saw_errors()); + return gogo->backend()->error_expression(); + } + ret = gogo->backend()->float_constant_expression(btype, fval); + mpfr_clear(fval); + } + else if (type->complex_type() != NULL) + { + mpfr_t real; + mpfr_t imag; + if (!val->to_complex(&real, &imag)) + { + go_assert(saw_errors()); + return gogo->backend()->error_expression(); + } + ret = gogo->backend()->complex_constant_expression(btype, real, imag); + mpfr_clear(real); + mpfr_clear(imag); + } + else + go_unreachable(); + + return ret; +} + +// Return a tree which evaluates to true if VAL, of arbitrary integer +// type, is negative or is more than the maximum value of BOUND_TYPE. +// If SOFAR is not NULL, it is or'red into the result. The return +// value may be NULL if SOFAR is NULL. + +tree +Expression::check_bounds(tree val, tree bound_type, tree sofar, + Location loc) +{ + tree val_type = TREE_TYPE(val); + tree ret = NULL_TREE; + + if (!TYPE_UNSIGNED(val_type)) + { + ret = fold_build2_loc(loc.gcc_location(), LT_EXPR, boolean_type_node, val, + build_int_cst(val_type, 0)); + if (ret == boolean_false_node) + ret = NULL_TREE; + } + + HOST_WIDE_INT val_type_size = int_size_in_bytes(val_type); + HOST_WIDE_INT bound_type_size = int_size_in_bytes(bound_type); + go_assert(val_type_size != -1 && bound_type_size != -1); + if (val_type_size > bound_type_size + || (val_type_size == bound_type_size + && TYPE_UNSIGNED(val_type) + && !TYPE_UNSIGNED(bound_type))) + { + tree max = TYPE_MAX_VALUE(bound_type); + tree big = fold_build2_loc(loc.gcc_location(), GT_EXPR, boolean_type_node, + val, fold_convert_loc(loc.gcc_location(), + val_type, max)); + if (big == boolean_false_node) + ; + else if (ret == NULL_TREE) + ret = big; + else + ret = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, ret, big); + } + + if (ret == NULL_TREE) + return sofar; + else if (sofar == NULL_TREE) + return ret; + else + return fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, boolean_type_node, + sofar, ret); +} + +void +Expression::dump_expression(Ast_dump_context* ast_dump_context) const +{ + this->do_dump_expression(ast_dump_context); +} + +// Error expressions. This are used to avoid cascading errors. + +class Error_expression : public Expression +{ + public: + Error_expression(Location location) + : Expression(EXPRESSION_ERROR, location) + { } + + protected: + bool + do_is_constant() const + { return true; } + + bool + do_numeric_constant_value(Numeric_constant* nc) const + { + nc->set_unsigned_long(NULL, 0); + return true; + } + + bool + do_discarding_value() + { return true; } + + Type* + do_type() + { return Type::make_error_type(); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return this; } + + bool + do_is_addressable() const + { return true; } + + tree + do_get_tree(Translate_context*) + { return error_mark_node; } + + void + do_dump_expression(Ast_dump_context*) const; +}; + +// Dump the ast representation for an error expression to a dump context. + +void +Error_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "_Error_" ; +} + +Expression* +Expression::make_error(Location location) +{ + return new Error_expression(location); +} + +// An expression which is really a type. This is used during parsing. +// It is an error if these survive after lowering. + +class +Type_expression : public Expression +{ + public: + Type_expression(Type* type, Location location) + : Expression(EXPRESSION_TYPE, location), + type_(type) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return Type::traverse(this->type_, traverse); } + + Type* + do_type() + { return this->type_; } + + void + do_determine_type(const Type_context*) + { } + + void + do_check_types(Gogo*) + { this->report_error(_("invalid use of type")); } + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context*) + { go_unreachable(); } + + void do_dump_expression(Ast_dump_context*) const; + + private: + // The type which we are representing as an expression. + Type* type_; +}; + +void +Type_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_type(this->type_); +} + +Expression* +Expression::make_type(Type* type, Location location) +{ + return new Type_expression(type, location); +} + +// Class Parser_expression. + +Type* +Parser_expression::do_type() +{ + // We should never really ask for the type of a Parser_expression. + // However, it can happen, at least when we have an invalid const + // whose initializer refers to the const itself. In that case we + // may ask for the type when lowering the const itself. + go_assert(saw_errors()); + return Type::make_error_type(); +} + +// Class Var_expression. + +// Lower a variable expression. Here we just make sure that the +// initialization expression of the variable has been lowered. This +// ensures that we will be able to determine the type of the variable +// if necessary. + +Expression* +Var_expression::do_lower(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, int) +{ + if (this->variable_->is_variable()) + { + Variable* var = this->variable_->var_value(); + // This is either a local variable or a global variable. A + // reference to a variable which is local to an enclosing + // function will be a reference to a field in a closure. + if (var->is_global()) + { + function = NULL; + inserter = NULL; + } + var->lower_init_expression(gogo, function, inserter); + } + return this; +} + +// Return the type of a reference to a variable. + +Type* +Var_expression::do_type() +{ + if (this->variable_->is_variable()) + return this->variable_->var_value()->type(); + else if (this->variable_->is_result_variable()) + return this->variable_->result_var_value()->type(); + else + go_unreachable(); +} + +// Determine the type of a reference to a variable. + +void +Var_expression::do_determine_type(const Type_context*) +{ + if (this->variable_->is_variable()) + this->variable_->var_value()->determine_type(); +} + +// Something takes the address of this variable. This means that we +// may want to move the variable onto the heap. + +void +Var_expression::do_address_taken(bool escapes) +{ + if (!escapes) + { + if (this->variable_->is_variable()) + this->variable_->var_value()->set_non_escaping_address_taken(); + else if (this->variable_->is_result_variable()) + this->variable_->result_var_value()->set_non_escaping_address_taken(); + else + go_unreachable(); + } + else + { + if (this->variable_->is_variable()) + this->variable_->var_value()->set_address_taken(); + else if (this->variable_->is_result_variable()) + this->variable_->result_var_value()->set_address_taken(); + else + go_unreachable(); + } +} + +// Get the tree for a reference to a variable. + +tree +Var_expression::do_get_tree(Translate_context* context) +{ + Bvariable* bvar = this->variable_->get_backend_variable(context->gogo(), + context->function()); + bool is_in_heap; + Location loc = this->location(); + if (this->variable_->is_variable()) + is_in_heap = this->variable_->var_value()->is_in_heap(); + else if (this->variable_->is_result_variable()) + is_in_heap = this->variable_->result_var_value()->is_in_heap(); + else + go_unreachable(); + + Bexpression* ret = context->backend()->var_expression(bvar, loc); + if (is_in_heap) + ret = context->backend()->indirect_expression(ret, true, loc); + return expr_to_tree(ret); +} + +// Ast dump for variable expression. + +void +Var_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << this->variable_->name() ; +} + +// Make a reference to a variable in an expression. + +Expression* +Expression::make_var_reference(Named_object* var, Location location) +{ + if (var->is_sink()) + return Expression::make_sink(location); + + // FIXME: Creating a new object for each reference to a variable is + // wasteful. + return new Var_expression(var, location); +} + +// Class Temporary_reference_expression. + +// The type. + +Type* +Temporary_reference_expression::do_type() +{ + return this->statement_->type(); +} + +// Called if something takes the address of this temporary variable. +// We never have to move temporary variables to the heap, but we do +// need to know that they must live in the stack rather than in a +// register. + +void +Temporary_reference_expression::do_address_taken(bool) +{ + this->statement_->set_is_address_taken(); +} + +// Get a tree referring to the variable. + +tree +Temporary_reference_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Bvariable* bvar = this->statement_->get_backend_variable(context); + Bexpression* ret = gogo->backend()->var_expression(bvar, this->location()); + + // The backend can't always represent the same set of recursive types + // that the Go frontend can. In some cases this means that a + // temporary variable won't have the right backend type. Correct + // that here by adding a type cast. We need to use base() to push + // the circularity down one level. + Type* stype = this->statement_->type(); + if (!this->is_lvalue_ + && stype->has_pointer() + && stype->deref()->is_void_type()) + { + Btype* btype = this->type()->base()->get_backend(gogo); + ret = gogo->backend()->convert_expression(btype, ret, this->location()); + } + return expr_to_tree(ret); +} + +// Ast dump for temporary reference. + +void +Temporary_reference_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_temp_variable_name(this->statement_); +} + +// Make a reference to a temporary variable. + +Temporary_reference_expression* +Expression::make_temporary_reference(Temporary_statement* statement, + Location location) +{ + return new Temporary_reference_expression(statement, location); +} + +// Class Set_and_use_temporary_expression. + +// Return the type. + +Type* +Set_and_use_temporary_expression::do_type() +{ + return this->statement_->type(); +} + +// Determine the type of the expression. + +void +Set_and_use_temporary_expression::do_determine_type( + const Type_context* context) +{ + this->expr_->determine_type(context); +} + +// Take the address. + +void +Set_and_use_temporary_expression::do_address_taken(bool) +{ + this->statement_->set_is_address_taken(); +} + +// Return the backend representation. + +tree +Set_and_use_temporary_expression::do_get_tree(Translate_context* context) +{ + Bvariable* bvar = this->statement_->get_backend_variable(context); + tree var_tree = var_to_tree(bvar); + tree expr_tree = this->expr_->get_tree(context); + if (var_tree == error_mark_node || expr_tree == error_mark_node) + return error_mark_node; + Location loc = this->location(); + return build2_loc(loc.gcc_location(), COMPOUND_EXPR, TREE_TYPE(var_tree), + build2_loc(loc.gcc_location(), MODIFY_EXPR, void_type_node, + var_tree, expr_tree), + var_tree); +} + +// Dump. + +void +Set_and_use_temporary_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << '('; + ast_dump_context->dump_temp_variable_name(this->statement_); + ast_dump_context->ostream() << " = "; + this->expr_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << ')'; +} + +// Make a set-and-use temporary. + +Set_and_use_temporary_expression* +Expression::make_set_and_use_temporary(Temporary_statement* statement, + Expression* expr, Location location) +{ + return new Set_and_use_temporary_expression(statement, expr, location); +} + +// A sink expression--a use of the blank identifier _. + +class Sink_expression : public Expression +{ + public: + Sink_expression(Location location) + : Expression(EXPRESSION_SINK, location), + type_(NULL), var_(NULL_TREE) + { } + + protected: + bool + do_discarding_value() + { return true; } + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + Expression* + do_copy() + { return new Sink_expression(this->location()); } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type of this sink variable. + Type* type_; + // The temporary variable we generate. + tree var_; +}; + +// Return the type of a sink expression. + +Type* +Sink_expression::do_type() +{ + if (this->type_ == NULL) + return Type::make_sink_type(); + return this->type_; +} + +// Determine the type of a sink expression. + +void +Sink_expression::do_determine_type(const Type_context* context) +{ + if (context->type != NULL) + this->type_ = context->type; +} + +// Return a temporary variable for a sink expression. This will +// presumably be a write-only variable which the middle-end will drop. + +tree +Sink_expression::do_get_tree(Translate_context* context) +{ + if (this->var_ == NULL_TREE) + { + go_assert(this->type_ != NULL && !this->type_->is_sink_type()); + Btype* bt = this->type_->get_backend(context->gogo()); + this->var_ = create_tmp_var(type_to_tree(bt), "blank"); + } + return this->var_; +} + +// Ast dump for sink expression. + +void +Sink_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "_" ; +} + +// Make a sink expression. + +Expression* +Expression::make_sink(Location location) +{ + return new Sink_expression(location); +} + +// Class Func_expression. + +// FIXME: Can a function expression appear in a constant expression? +// The value is unchanging. Initializing a constant to the address of +// a function seems like it could work, though there might be little +// point to it. + +// Traversal. + +int +Func_expression::do_traverse(Traverse* traverse) +{ + return (this->closure_ == NULL + ? TRAVERSE_CONTINUE + : Expression::traverse(&this->closure_, traverse)); +} + +// Return the type of a function expression. + +Type* +Func_expression::do_type() +{ + if (this->function_->is_function()) + return this->function_->func_value()->type(); + else if (this->function_->is_function_declaration()) + return this->function_->func_declaration_value()->type(); + else + go_unreachable(); +} + +// Get the tree for the code of a function expression. + +Bexpression* +Func_expression::get_code_pointer(Gogo* gogo, Named_object* no, Location loc) +{ + Function_type* fntype; + if (no->is_function()) + fntype = no->func_value()->type(); + else if (no->is_function_declaration()) + fntype = no->func_declaration_value()->type(); + else + go_unreachable(); + + // Builtin functions are handled specially by Call_expression. We + // can't take their address. + if (fntype->is_builtin()) + { + error_at(loc, + "invalid use of special builtin function %qs; must be called", + no->message_name().c_str()); + return gogo->backend()->error_expression(); + } + + Bfunction* fndecl; + if (no->is_function()) + fndecl = no->func_value()->get_or_make_decl(gogo, no); + else if (no->is_function_declaration()) + fndecl = no->func_declaration_value()->get_or_make_decl(gogo, no); + else + go_unreachable(); + + return gogo->backend()->function_code_expression(fndecl, loc); +} + +// Get the tree for a function expression. This is used when we take +// the address of a function rather than simply calling it. A func +// value is represented as a pointer to a block of memory. The first +// word of that memory is a pointer to the function code. The +// remaining parts of that memory are the addresses of variables that +// the function closes over. + +tree +Func_expression::do_get_tree(Translate_context* context) +{ + // If there is no closure, just use the function descriptor. + if (this->closure_ == NULL) + { + Gogo* gogo = context->gogo(); + Named_object* no = this->function_; + Expression* descriptor; + if (no->is_function()) + descriptor = no->func_value()->descriptor(gogo, no); + else if (no->is_function_declaration()) + { + if (no->func_declaration_value()->type()->is_builtin()) + { + error_at(this->location(), + ("invalid use of special builtin function %qs; " + "must be called"), + no->message_name().c_str()); + return error_mark_node; + } + descriptor = no->func_declaration_value()->descriptor(gogo, no); + } + else + go_unreachable(); + + tree dtree = descriptor->get_tree(context); + if (dtree == error_mark_node) + return error_mark_node; + return build_fold_addr_expr_loc(this->location().gcc_location(), dtree); + } + + go_assert(this->function_->func_value()->enclosing() != NULL); + + // If there is a closure, then the closure is itself the function + // expression. It is a pointer to a struct whose first field points + // to the function code and whose remaining fields are the addresses + // of the closed-over variables. + return this->closure_->get_tree(context); +} + +// Ast dump for function. + +void +Func_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << this->function_->name(); + if (this->closure_ != NULL) + { + ast_dump_context->ostream() << " {closure = "; + this->closure_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << "}"; + } +} + +// Make a reference to a function in an expression. + +Expression* +Expression::make_func_reference(Named_object* function, Expression* closure, + Location location) +{ + return new Func_expression(function, closure, location); +} + +// Class Func_descriptor_expression. + +// Constructor. + +Func_descriptor_expression::Func_descriptor_expression(Named_object* fn) + : Expression(EXPRESSION_FUNC_DESCRIPTOR, fn->location()), + fn_(fn), dvar_(NULL) +{ + go_assert(!fn->is_function() || !fn->func_value()->needs_closure()); +} + +// Traversal. + +int +Func_descriptor_expression::do_traverse(Traverse*) +{ + return TRAVERSE_CONTINUE; +} + +// All function descriptors have the same type. + +Type* Func_descriptor_expression::descriptor_type; + +void +Func_descriptor_expression::make_func_descriptor_type() +{ + if (Func_descriptor_expression::descriptor_type != NULL) + return; + Type* uintptr_type = Type::lookup_integer_type("uintptr"); + Type* struct_type = Type::make_builtin_struct_type(1, "code", uintptr_type); + Func_descriptor_expression::descriptor_type = + Type::make_builtin_named_type("functionDescriptor", struct_type); +} + +Type* +Func_descriptor_expression::do_type() +{ + Func_descriptor_expression::make_func_descriptor_type(); + return Func_descriptor_expression::descriptor_type; +} + +// The tree for a function descriptor. + +tree +Func_descriptor_expression::do_get_tree(Translate_context* context) +{ + if (this->dvar_ != NULL) + return var_to_tree(this->dvar_); + + Gogo* gogo = context->gogo(); + Named_object* no = this->fn_; + Location loc = no->location(); + + std::string var_name; + if (no->package() == NULL) + var_name = gogo->pkgpath_symbol(); + else + var_name = no->package()->pkgpath_symbol(); + var_name.push_back('.'); + var_name.append(Gogo::unpack_hidden_name(no->name())); + var_name.append("$descriptor"); + + Btype* btype = this->type()->get_backend(gogo); + + Bvariable* bvar; + if (no->package() != NULL + || Linemap::is_predeclared_location(no->location())) + bvar = context->backend()->immutable_struct_reference(var_name, btype, + loc); + else + { + Location bloc = Linemap::predeclared_location(); + bool is_hidden = ((no->is_function() + && no->func_value()->enclosing() != NULL) + || Gogo::is_thunk(no)); + bvar = context->backend()->immutable_struct(var_name, is_hidden, false, + btype, bloc); + Expression_list* vals = new Expression_list(); + vals->push_back(Expression::make_func_code_reference(this->fn_, bloc)); + Expression* init = + Expression::make_struct_composite_literal(this->type(), vals, bloc); + Translate_context bcontext(gogo, NULL, NULL, NULL); + bcontext.set_is_const(); + Bexpression* binit = tree_to_expr(init->get_tree(&bcontext)); + context->backend()->immutable_struct_set_init(bvar, var_name, is_hidden, + false, btype, bloc, binit); + } + + this->dvar_ = bvar; + return var_to_tree(bvar); +} + +// Print a function descriptor expression. + +void +Func_descriptor_expression::do_dump_expression(Ast_dump_context* context) const +{ + context->ostream() << "[descriptor " << this->fn_->name() << "]"; +} + +// Make a function descriptor expression. + +Func_descriptor_expression* +Expression::make_func_descriptor(Named_object* fn) +{ + return new Func_descriptor_expression(fn); +} + +// Make the function descriptor type, so that it can be converted. + +void +Expression::make_func_descriptor_type() +{ + Func_descriptor_expression::make_func_descriptor_type(); +} + +// A reference to just the code of a function. + +class Func_code_reference_expression : public Expression +{ + public: + Func_code_reference_expression(Named_object* function, Location location) + : Expression(EXPRESSION_FUNC_CODE_REFERENCE, location), + function_(function) + { } + + protected: + int + do_traverse(Traverse*) + { return TRAVERSE_CONTINUE; } + + bool + do_is_immutable() const + { return true; } + + Type* + do_type() + { return Type::make_pointer_type(Type::make_void_type()); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { + return Expression::make_func_code_reference(this->function_, + this->location()); + } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context* context) const + { context->ostream() << "[raw " << this->function_->name() << "]" ; } + + private: + // The function. + Named_object* function_; +}; + +// Get the tree for a reference to function code. + +tree +Func_code_reference_expression::do_get_tree(Translate_context* context) +{ + Bexpression* ret = + Func_expression::get_code_pointer(context->gogo(), this->function_, + this->location()); + return expr_to_tree(ret); +} + +// Make a reference to the code of a function. + +Expression* +Expression::make_func_code_reference(Named_object* function, Location location) +{ + return new Func_code_reference_expression(function, location); +} + +// Class Unknown_expression. + +// Return the name of an unknown expression. + +const std::string& +Unknown_expression::name() const +{ + return this->named_object_->name(); +} + +// Lower a reference to an unknown name. + +Expression* +Unknown_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int) +{ + Location location = this->location(); + Named_object* no = this->named_object_; + Named_object* real; + if (!no->is_unknown()) + real = no; + else + { + real = no->unknown_value()->real_named_object(); + if (real == NULL) + { + if (this->is_composite_literal_key_) + return this; + if (!this->no_error_message_) + error_at(location, "reference to undefined name %qs", + this->named_object_->message_name().c_str()); + return Expression::make_error(location); + } + } + switch (real->classification()) + { + case Named_object::NAMED_OBJECT_CONST: + return Expression::make_const_reference(real, location); + case Named_object::NAMED_OBJECT_TYPE: + return Expression::make_type(real->type_value(), location); + case Named_object::NAMED_OBJECT_TYPE_DECLARATION: + if (this->is_composite_literal_key_) + return this; + if (!this->no_error_message_) + error_at(location, "reference to undefined type %qs", + real->message_name().c_str()); + return Expression::make_error(location); + case Named_object::NAMED_OBJECT_VAR: + real->var_value()->set_is_used(); + return Expression::make_var_reference(real, location); + case Named_object::NAMED_OBJECT_FUNC: + case Named_object::NAMED_OBJECT_FUNC_DECLARATION: + return Expression::make_func_reference(real, NULL, location); + case Named_object::NAMED_OBJECT_PACKAGE: + if (this->is_composite_literal_key_) + return this; + if (!this->no_error_message_) + error_at(location, "unexpected reference to package"); + return Expression::make_error(location); + default: + go_unreachable(); + } +} + +// Dump the ast representation for an unknown expression to a dump context. + +void +Unknown_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "_Unknown_(" << this->named_object_->name() + << ")"; +} + +// Make a reference to an unknown name. + +Unknown_expression* +Expression::make_unknown_reference(Named_object* no, Location location) +{ + return new Unknown_expression(no, location); +} + +// A boolean expression. + +class Boolean_expression : public Expression +{ + public: + Boolean_expression(bool val, Location location) + : Expression(EXPRESSION_BOOLEAN, location), + val_(val), type_(NULL) + { } + + static Expression* + do_import(Import*); + + protected: + bool + do_is_constant() const + { return true; } + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context*) + { return this->val_ ? boolean_true_node : boolean_false_node; } + + void + do_export(Export* exp) const + { exp->write_c_string(this->val_ ? "true" : "false"); } + + void + do_dump_expression(Ast_dump_context* ast_dump_context) const + { ast_dump_context->ostream() << (this->val_ ? "true" : "false"); } + + private: + // The constant. + bool val_; + // The type as determined by context. + Type* type_; +}; + +// Get the type. + +Type* +Boolean_expression::do_type() +{ + if (this->type_ == NULL) + this->type_ = Type::make_boolean_type(); + return this->type_; +} + +// Set the type from the context. + +void +Boolean_expression::do_determine_type(const Type_context* context) +{ + if (this->type_ != NULL && !this->type_->is_abstract()) + ; + else if (context->type != NULL && context->type->is_boolean_type()) + this->type_ = context->type; + else if (!context->may_be_abstract) + this->type_ = Type::lookup_bool_type(); +} + +// Import a boolean constant. + +Expression* +Boolean_expression::do_import(Import* imp) +{ + if (imp->peek_char() == 't') + { + imp->require_c_string("true"); + return Expression::make_boolean(true, imp->location()); + } + else + { + imp->require_c_string("false"); + return Expression::make_boolean(false, imp->location()); + } +} + +// Make a boolean expression. + +Expression* +Expression::make_boolean(bool val, Location location) +{ + return new Boolean_expression(val, location); +} + +// Class String_expression. + +// Get the type. + +Type* +String_expression::do_type() +{ + if (this->type_ == NULL) + this->type_ = Type::make_string_type(); + return this->type_; +} + +// Set the type from the context. + +void +String_expression::do_determine_type(const Type_context* context) +{ + if (this->type_ != NULL && !this->type_->is_abstract()) + ; + else if (context->type != NULL && context->type->is_string_type()) + this->type_ = context->type; + else if (!context->may_be_abstract) + this->type_ = Type::lookup_string_type(); +} + +// Build a string constant. + +tree +String_expression::do_get_tree(Translate_context* context) +{ + return context->gogo()->go_string_constant_tree(this->val_); +} + + // Write string literal to string dump. + +void +String_expression::export_string(String_dump* exp, + const String_expression* str) +{ + std::string s; + s.reserve(str->val_.length() * 4 + 2); + s += '"'; + for (std::string::const_iterator p = str->val_.begin(); + p != str->val_.end(); + ++p) + { + if (*p == '\\' || *p == '"') + { + s += '\\'; + s += *p; + } + else if (*p >= 0x20 && *p < 0x7f) + s += *p; + else if (*p == '\n') + s += "\\n"; + else if (*p == '\t') + s += "\\t"; + else + { + s += "\\x"; + unsigned char c = *p; + unsigned int dig = c >> 4; + s += dig < 10 ? '0' + dig : 'A' + dig - 10; + dig = c & 0xf; + s += dig < 10 ? '0' + dig : 'A' + dig - 10; + } + } + s += '"'; + exp->write_string(s); +} + +// Export a string expression. + +void +String_expression::do_export(Export* exp) const +{ + String_expression::export_string(exp, this); +} + +// Import a string expression. + +Expression* +String_expression::do_import(Import* imp) +{ + imp->require_c_string("\""); + std::string val; + while (true) + { + int c = imp->get_char(); + if (c == '"' || c == -1) + break; + if (c != '\\') + val += static_cast<char>(c); + else + { + c = imp->get_char(); + if (c == '\\' || c == '"') + val += static_cast<char>(c); + else if (c == 'n') + val += '\n'; + else if (c == 't') + val += '\t'; + else if (c == 'x') + { + c = imp->get_char(); + unsigned int vh = c >= '0' && c <= '9' ? c - '0' : c - 'A' + 10; + c = imp->get_char(); + unsigned int vl = c >= '0' && c <= '9' ? c - '0' : c - 'A' + 10; + char v = (vh << 4) | vl; + val += v; + } + else + { + error_at(imp->location(), "bad string constant"); + return Expression::make_error(imp->location()); + } + } + } + return Expression::make_string(val, imp->location()); +} + +// Ast dump for string expression. + +void +String_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + String_expression::export_string(ast_dump_context, this); +} + +// Make a string expression. + +Expression* +Expression::make_string(const std::string& val, Location location) +{ + return new String_expression(val, location); +} + +// Make an integer expression. + +class Integer_expression : public Expression +{ + public: + Integer_expression(const mpz_t* val, Type* type, bool is_character_constant, + Location location) + : Expression(EXPRESSION_INTEGER, location), + type_(type), is_character_constant_(is_character_constant) + { mpz_init_set(this->val_, *val); } + + static Expression* + do_import(Import*); + + // Write VAL to string dump. + static void + export_integer(String_dump* exp, const mpz_t val); + + // Write VAL to dump context. + static void + dump_integer(Ast_dump_context* ast_dump_context, const mpz_t val); + + protected: + bool + do_is_constant() const + { return true; } + + bool + do_numeric_constant_value(Numeric_constant* nc) const; + + Type* + do_type(); + + void + do_determine_type(const Type_context* context); + + void + do_check_types(Gogo*); + + tree + do_get_tree(Translate_context*); + + Expression* + do_copy() + { + if (this->is_character_constant_) + return Expression::make_character(&this->val_, this->type_, + this->location()); + else + return Expression::make_integer(&this->val_, this->type_, + this->location()); + } + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The integer value. + mpz_t val_; + // The type so far. + Type* type_; + // Whether this is a character constant. + bool is_character_constant_; +}; + +// Return a numeric constant for this expression. We have to mark +// this as a character when appropriate. + +bool +Integer_expression::do_numeric_constant_value(Numeric_constant* nc) const +{ + if (this->is_character_constant_) + nc->set_rune(this->type_, this->val_); + else + nc->set_int(this->type_, this->val_); + return true; +} + +// Return the current type. If we haven't set the type yet, we return +// an abstract integer type. + +Type* +Integer_expression::do_type() +{ + if (this->type_ == NULL) + { + if (this->is_character_constant_) + this->type_ = Type::make_abstract_character_type(); + else + this->type_ = Type::make_abstract_integer_type(); + } + return this->type_; +} + +// Set the type of the integer value. Here we may switch from an +// abstract type to a real type. + +void +Integer_expression::do_determine_type(const Type_context* context) +{ + if (this->type_ != NULL && !this->type_->is_abstract()) + ; + else if (context->type != NULL && context->type->is_numeric_type()) + this->type_ = context->type; + else if (!context->may_be_abstract) + { + if (this->is_character_constant_) + this->type_ = Type::lookup_integer_type("int32"); + else + this->type_ = Type::lookup_integer_type("int"); + } +} + +// Check the type of an integer constant. + +void +Integer_expression::do_check_types(Gogo*) +{ + Type* type = this->type_; + if (type == NULL) + return; + Numeric_constant nc; + if (this->is_character_constant_) + nc.set_rune(NULL, this->val_); + else + nc.set_int(NULL, this->val_); + if (!nc.set_type(type, true, this->location())) + this->set_is_error(); +} + +// Get a tree for an integer constant. + +tree +Integer_expression::do_get_tree(Translate_context* context) +{ + Type* resolved_type = NULL; + if (this->type_ != NULL && !this->type_->is_abstract()) + resolved_type = this->type_; + else if (this->type_ != NULL && this->type_->float_type() != NULL) + { + // We are converting to an abstract floating point type. + resolved_type = Type::lookup_float_type("float64"); + } + else if (this->type_ != NULL && this->type_->complex_type() != NULL) + { + // We are converting to an abstract complex type. + resolved_type = Type::lookup_complex_type("complex128"); + } + else + { + // If we still have an abstract type here, then this is being + // used in a constant expression which didn't get reduced for + // some reason. Use a type which will fit the value. We use <, + // not <=, because we need an extra bit for the sign bit. + int bits = mpz_sizeinbase(this->val_, 2); + Type* int_type = Type::lookup_integer_type("int"); + if (bits < int_type->integer_type()->bits()) + resolved_type = int_type; + else if (bits < 64) + resolved_type = Type::lookup_integer_type("int64"); + else + { + if (!saw_errors()) + error_at(this->location(), + "unknown type for large integer constant"); + Bexpression* ret = context->gogo()->backend()->error_expression(); + return expr_to_tree(ret); + } + } + Numeric_constant nc; + nc.set_int(resolved_type, this->val_); + Bexpression* ret = + Expression::backend_numeric_constant_expression(context, &nc); + return expr_to_tree(ret); +} + +// Write VAL to export data. + +void +Integer_expression::export_integer(String_dump* exp, const mpz_t val) +{ + char* s = mpz_get_str(NULL, 10, val); + exp->write_c_string(s); + free(s); +} + +// Export an integer in a constant expression. + +void +Integer_expression::do_export(Export* exp) const +{ + Integer_expression::export_integer(exp, this->val_); + if (this->is_character_constant_) + exp->write_c_string("'"); + // A trailing space lets us reliably identify the end of the number. + exp->write_c_string(" "); +} + +// Import an integer, floating point, or complex value. This handles +// all these types because they all start with digits. + +Expression* +Integer_expression::do_import(Import* imp) +{ + std::string num = imp->read_identifier(); + imp->require_c_string(" "); + if (!num.empty() && num[num.length() - 1] == 'i') + { + mpfr_t real; + size_t plus_pos = num.find('+', 1); + size_t minus_pos = num.find('-', 1); + size_t pos; + if (plus_pos == std::string::npos) + pos = minus_pos; + else if (minus_pos == std::string::npos) + pos = plus_pos; + else + { + error_at(imp->location(), "bad number in import data: %qs", + num.c_str()); + return Expression::make_error(imp->location()); + } + if (pos == std::string::npos) + mpfr_set_ui(real, 0, GMP_RNDN); + else + { + std::string real_str = num.substr(0, pos); + if (mpfr_init_set_str(real, real_str.c_str(), 10, GMP_RNDN) != 0) + { + error_at(imp->location(), "bad number in import data: %qs", + real_str.c_str()); + return Expression::make_error(imp->location()); + } + } + + std::string imag_str; + if (pos == std::string::npos) + imag_str = num; + else + imag_str = num.substr(pos); + imag_str = imag_str.substr(0, imag_str.size() - 1); + mpfr_t imag; + if (mpfr_init_set_str(imag, imag_str.c_str(), 10, GMP_RNDN) != 0) + { + error_at(imp->location(), "bad number in import data: %qs", + imag_str.c_str()); + return Expression::make_error(imp->location()); + } + Expression* ret = Expression::make_complex(&real, &imag, NULL, + imp->location()); + mpfr_clear(real); + mpfr_clear(imag); + return ret; + } + else if (num.find('.') == std::string::npos + && num.find('E') == std::string::npos) + { + bool is_character_constant = (!num.empty() + && num[num.length() - 1] == '\''); + if (is_character_constant) + num = num.substr(0, num.length() - 1); + mpz_t val; + if (mpz_init_set_str(val, num.c_str(), 10) != 0) + { + error_at(imp->location(), "bad number in import data: %qs", + num.c_str()); + return Expression::make_error(imp->location()); + } + Expression* ret; + if (is_character_constant) + ret = Expression::make_character(&val, NULL, imp->location()); + else + ret = Expression::make_integer(&val, NULL, imp->location()); + mpz_clear(val); + return ret; + } + else + { + mpfr_t val; + if (mpfr_init_set_str(val, num.c_str(), 10, GMP_RNDN) != 0) + { + error_at(imp->location(), "bad number in import data: %qs", + num.c_str()); + return Expression::make_error(imp->location()); + } + Expression* ret = Expression::make_float(&val, NULL, imp->location()); + mpfr_clear(val); + return ret; + } +} +// Ast dump for integer expression. + +void +Integer_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + if (this->is_character_constant_) + ast_dump_context->ostream() << '\''; + Integer_expression::export_integer(ast_dump_context, this->val_); + if (this->is_character_constant_) + ast_dump_context->ostream() << '\''; +} + +// Build a new integer value. + +Expression* +Expression::make_integer(const mpz_t* val, Type* type, Location location) +{ + return new Integer_expression(val, type, false, location); +} + +// Build a new character constant value. + +Expression* +Expression::make_character(const mpz_t* val, Type* type, Location location) +{ + return new Integer_expression(val, type, true, location); +} + +// Floats. + +class Float_expression : public Expression +{ + public: + Float_expression(const mpfr_t* val, Type* type, Location location) + : Expression(EXPRESSION_FLOAT, location), + type_(type) + { + mpfr_init_set(this->val_, *val, GMP_RNDN); + } + + // Write VAL to export data. + static void + export_float(String_dump* exp, const mpfr_t val); + + // Write VAL to dump file. + static void + dump_float(Ast_dump_context* ast_dump_context, const mpfr_t val); + + protected: + bool + do_is_constant() const + { return true; } + + bool + do_numeric_constant_value(Numeric_constant* nc) const + { + nc->set_float(this->type_, this->val_); + return true; + } + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { return Expression::make_float(&this->val_, this->type_, + this->location()); } + + tree + do_get_tree(Translate_context*); + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The floating point value. + mpfr_t val_; + // The type so far. + Type* type_; +}; + +// Return the current type. If we haven't set the type yet, we return +// an abstract float type. + +Type* +Float_expression::do_type() +{ + if (this->type_ == NULL) + this->type_ = Type::make_abstract_float_type(); + return this->type_; +} + +// Set the type of the float value. Here we may switch from an +// abstract type to a real type. + +void +Float_expression::do_determine_type(const Type_context* context) +{ + if (this->type_ != NULL && !this->type_->is_abstract()) + ; + else if (context->type != NULL + && (context->type->integer_type() != NULL + || context->type->float_type() != NULL + || context->type->complex_type() != NULL)) + this->type_ = context->type; + else if (!context->may_be_abstract) + this->type_ = Type::lookup_float_type("float64"); +} + +// Check the type of a float value. + +void +Float_expression::do_check_types(Gogo*) +{ + Type* type = this->type_; + if (type == NULL) + return; + Numeric_constant nc; + nc.set_float(NULL, this->val_); + if (!nc.set_type(this->type_, true, this->location())) + this->set_is_error(); +} + +// Get a tree for a float constant. + +tree +Float_expression::do_get_tree(Translate_context* context) +{ + Type* resolved_type; + if (this->type_ != NULL && !this->type_->is_abstract()) + resolved_type = this->type_; + else if (this->type_ != NULL && this->type_->integer_type() != NULL) + { + // We have an abstract integer type. We just hope for the best. + resolved_type = Type::lookup_integer_type("int"); + } + else if (this->type_ != NULL && this->type_->complex_type() != NULL) + { + // We are converting to an abstract complex type. + resolved_type = Type::lookup_complex_type("complex128"); + } + else + { + // If we still have an abstract type here, then this is being + // used in a constant expression which didn't get reduced. We + // just use float64 and hope for the best. + resolved_type = Type::lookup_float_type("float64"); + } + + Numeric_constant nc; + nc.set_float(resolved_type, this->val_); + Bexpression* ret = + Expression::backend_numeric_constant_expression(context, &nc); + return expr_to_tree(ret); +} + +// Write a floating point number to a string dump. + +void +Float_expression::export_float(String_dump *exp, const mpfr_t val) +{ + mp_exp_t exponent; + char* s = mpfr_get_str(NULL, &exponent, 10, 0, val, GMP_RNDN); + if (*s == '-') + exp->write_c_string("-"); + exp->write_c_string("0."); + exp->write_c_string(*s == '-' ? s + 1 : s); + mpfr_free_str(s); + char buf[30]; + snprintf(buf, sizeof buf, "E%ld", exponent); + exp->write_c_string(buf); +} + +// Export a floating point number in a constant expression. + +void +Float_expression::do_export(Export* exp) const +{ + Float_expression::export_float(exp, this->val_); + // A trailing space lets us reliably identify the end of the number. + exp->write_c_string(" "); +} + +// Dump a floating point number to the dump file. + +void +Float_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + Float_expression::export_float(ast_dump_context, this->val_); +} + +// Make a float expression. + +Expression* +Expression::make_float(const mpfr_t* val, Type* type, Location location) +{ + return new Float_expression(val, type, location); +} + +// Complex numbers. + +class Complex_expression : public Expression +{ + public: + Complex_expression(const mpfr_t* real, const mpfr_t* imag, Type* type, + Location location) + : Expression(EXPRESSION_COMPLEX, location), + type_(type) + { + mpfr_init_set(this->real_, *real, GMP_RNDN); + mpfr_init_set(this->imag_, *imag, GMP_RNDN); + } + + // Write REAL/IMAG to string dump. + static void + export_complex(String_dump* exp, const mpfr_t real, const mpfr_t val); + + // Write REAL/IMAG to dump context. + static void + dump_complex(Ast_dump_context* ast_dump_context, + const mpfr_t real, const mpfr_t val); + + protected: + bool + do_is_constant() const + { return true; } + + bool + do_numeric_constant_value(Numeric_constant* nc) const + { + nc->set_complex(this->type_, this->real_, this->imag_); + return true; + } + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return Expression::make_complex(&this->real_, &this->imag_, this->type_, + this->location()); + } + + tree + do_get_tree(Translate_context*); + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The real part. + mpfr_t real_; + // The imaginary part; + mpfr_t imag_; + // The type if known. + Type* type_; +}; + +// Return the current type. If we haven't set the type yet, we return +// an abstract complex type. + +Type* +Complex_expression::do_type() +{ + if (this->type_ == NULL) + this->type_ = Type::make_abstract_complex_type(); + return this->type_; +} + +// Set the type of the complex value. Here we may switch from an +// abstract type to a real type. + +void +Complex_expression::do_determine_type(const Type_context* context) +{ + if (this->type_ != NULL && !this->type_->is_abstract()) + ; + else if (context->type != NULL + && context->type->complex_type() != NULL) + this->type_ = context->type; + else if (!context->may_be_abstract) + this->type_ = Type::lookup_complex_type("complex128"); +} + +// Check the type of a complex value. + +void +Complex_expression::do_check_types(Gogo*) +{ + Type* type = this->type_; + if (type == NULL) + return; + Numeric_constant nc; + nc.set_complex(NULL, this->real_, this->imag_); + if (!nc.set_type(this->type_, true, this->location())) + this->set_is_error(); +} + +// Get a tree for a complex constant. + +tree +Complex_expression::do_get_tree(Translate_context* context) +{ + Type* resolved_type; + if (this->type_ != NULL && !this->type_->is_abstract()) + resolved_type = this->type_; + else if (this->type_ != NULL && this->type_->integer_type() != NULL) + { + // We are converting to an abstract integer type. + resolved_type = Type::lookup_integer_type("int"); + } + else if (this->type_ != NULL && this->type_->float_type() != NULL) + { + // We are converting to an abstract float type. + resolved_type = Type::lookup_float_type("float64"); + } + else + { + // If we still have an abstract type here, this this is being + // used in a constant expression which didn't get reduced. We + // just use complex128 and hope for the best. + resolved_type = Type::lookup_complex_type("complex128"); + } + + Numeric_constant nc; + nc.set_complex(resolved_type, this->real_, this->imag_); + Bexpression* ret = + Expression::backend_numeric_constant_expression(context, &nc); + return expr_to_tree(ret); +} + +// Write REAL/IMAG to export data. + +void +Complex_expression::export_complex(String_dump* exp, const mpfr_t real, + const mpfr_t imag) +{ + if (!mpfr_zero_p(real)) + { + Float_expression::export_float(exp, real); + if (mpfr_sgn(imag) > 0) + exp->write_c_string("+"); + } + Float_expression::export_float(exp, imag); + exp->write_c_string("i"); +} + +// Export a complex number in a constant expression. + +void +Complex_expression::do_export(Export* exp) const +{ + Complex_expression::export_complex(exp, this->real_, this->imag_); + // A trailing space lets us reliably identify the end of the number. + exp->write_c_string(" "); +} + +// Dump a complex expression to the dump file. + +void +Complex_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + Complex_expression::export_complex(ast_dump_context, + this->real_, + this->imag_); +} + +// Make a complex expression. + +Expression* +Expression::make_complex(const mpfr_t* real, const mpfr_t* imag, Type* type, + Location location) +{ + return new Complex_expression(real, imag, type, location); +} + +// Find a named object in an expression. + +class Find_named_object : public Traverse +{ + public: + Find_named_object(Named_object* no) + : Traverse(traverse_expressions), + no_(no), found_(false) + { } + + // Whether we found the object. + bool + found() const + { return this->found_; } + + protected: + int + expression(Expression**); + + private: + // The object we are looking for. + Named_object* no_; + // Whether we found it. + bool found_; +}; + +// A reference to a const in an expression. + +class Const_expression : public Expression +{ + public: + Const_expression(Named_object* constant, Location location) + : Expression(EXPRESSION_CONST_REFERENCE, location), + constant_(constant), type_(NULL), seen_(false) + { } + + Named_object* + named_object() + { return this->constant_; } + + // Check that the initializer does not refer to the constant itself. + void + check_for_init_loop(); + + protected: + int + do_traverse(Traverse*); + + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int); + + bool + do_is_constant() const + { return true; } + + bool + do_numeric_constant_value(Numeric_constant* nc) const; + + bool + do_string_constant_value(std::string* val) const; + + Type* + do_type(); + + // The type of a const is set by the declaration, not the use. + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context* context); + + // When exporting a reference to a const as part of a const + // expression, we export the value. We ignore the fact that it has + // a name. + void + do_export(Export* exp) const + { this->constant_->const_value()->expr()->export_expression(exp); } + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The constant. + Named_object* constant_; + // The type of this reference. This is used if the constant has an + // abstract type. + Type* type_; + // Used to prevent infinite recursion when a constant incorrectly + // refers to itself. + mutable bool seen_; +}; + +// Traversal. + +int +Const_expression::do_traverse(Traverse* traverse) +{ + if (this->type_ != NULL) + return Type::traverse(this->type_, traverse); + return TRAVERSE_CONTINUE; +} + +// Lower a constant expression. This is where we convert the +// predeclared constant iota into an integer value. + +Expression* +Const_expression::do_lower(Gogo* gogo, Named_object*, + Statement_inserter*, int iota_value) +{ + if (this->constant_->const_value()->expr()->classification() + == EXPRESSION_IOTA) + { + if (iota_value == -1) + { + error_at(this->location(), + "iota is only defined in const declarations"); + iota_value = 0; + } + mpz_t val; + mpz_init_set_ui(val, static_cast<unsigned long>(iota_value)); + Expression* ret = Expression::make_integer(&val, NULL, + this->location()); + mpz_clear(val); + return ret; + } + + // Make sure that the constant itself has been lowered. + gogo->lower_constant(this->constant_); + + return this; +} + +// Return a numeric constant value. + +bool +Const_expression::do_numeric_constant_value(Numeric_constant* nc) const +{ + if (this->seen_) + return false; + + Expression* e = this->constant_->const_value()->expr(); + + this->seen_ = true; + + bool r = e->numeric_constant_value(nc); + + this->seen_ = false; + + Type* ctype; + if (this->type_ != NULL) + ctype = this->type_; + else + ctype = this->constant_->const_value()->type(); + if (r && ctype != NULL) + { + if (!nc->set_type(ctype, false, this->location())) + return false; + } + + return r; +} + +bool +Const_expression::do_string_constant_value(std::string* val) const +{ + if (this->seen_) + return false; + + Expression* e = this->constant_->const_value()->expr(); + + this->seen_ = true; + bool ok = e->string_constant_value(val); + this->seen_ = false; + + return ok; +} + +// Return the type of the const reference. + +Type* +Const_expression::do_type() +{ + if (this->type_ != NULL) + return this->type_; + + Named_constant* nc = this->constant_->const_value(); + + if (this->seen_ || nc->lowering()) + { + this->report_error(_("constant refers to itself")); + this->type_ = Type::make_error_type(); + return this->type_; + } + + this->seen_ = true; + + Type* ret = nc->type(); + + if (ret != NULL) + { + this->seen_ = false; + return ret; + } + + // During parsing, a named constant may have a NULL type, but we + // must not return a NULL type here. + ret = nc->expr()->type(); + + this->seen_ = false; + + return ret; +} + +// Set the type of the const reference. + +void +Const_expression::do_determine_type(const Type_context* context) +{ + Type* ctype = this->constant_->const_value()->type(); + Type* cetype = (ctype != NULL + ? ctype + : this->constant_->const_value()->expr()->type()); + if (ctype != NULL && !ctype->is_abstract()) + ; + else if (context->type != NULL + && context->type->is_numeric_type() + && cetype->is_numeric_type()) + this->type_ = context->type; + else if (context->type != NULL + && context->type->is_string_type() + && cetype->is_string_type()) + this->type_ = context->type; + else if (context->type != NULL + && context->type->is_boolean_type() + && cetype->is_boolean_type()) + this->type_ = context->type; + else if (!context->may_be_abstract) + { + if (cetype->is_abstract()) + cetype = cetype->make_non_abstract_type(); + this->type_ = cetype; + } +} + +// Check for a loop in which the initializer of a constant refers to +// the constant itself. + +void +Const_expression::check_for_init_loop() +{ + if (this->type_ != NULL && this->type_->is_error()) + return; + + if (this->seen_) + { + this->report_error(_("constant refers to itself")); + this->type_ = Type::make_error_type(); + return; + } + + Expression* init = this->constant_->const_value()->expr(); + Find_named_object find_named_object(this->constant_); + + this->seen_ = true; + Expression::traverse(&init, &find_named_object); + this->seen_ = false; + + if (find_named_object.found()) + { + if (this->type_ == NULL || !this->type_->is_error()) + { + this->report_error(_("constant refers to itself")); + this->type_ = Type::make_error_type(); + } + return; + } +} + +// Check types of a const reference. + +void +Const_expression::do_check_types(Gogo*) +{ + if (this->type_ != NULL && this->type_->is_error()) + return; + + this->check_for_init_loop(); + + // Check that numeric constant fits in type. + if (this->type_ != NULL && this->type_->is_numeric_type()) + { + Numeric_constant nc; + if (this->constant_->const_value()->expr()->numeric_constant_value(&nc)) + { + if (!nc.set_type(this->type_, true, this->location())) + this->set_is_error(); + } + } +} + +// Return a tree for the const reference. + +tree +Const_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + tree type_tree; + if (this->type_ == NULL) + type_tree = NULL_TREE; + else + { + type_tree = type_to_tree(this->type_->get_backend(gogo)); + if (type_tree == error_mark_node) + return error_mark_node; + } + + // If the type has been set for this expression, but the underlying + // object is an abstract int or float, we try to get the abstract + // value. Otherwise we may lose something in the conversion. + if (this->type_ != NULL + && this->type_->is_numeric_type() + && (this->constant_->const_value()->type() == NULL + || this->constant_->const_value()->type()->is_abstract())) + { + Expression* expr = this->constant_->const_value()->expr(); + Numeric_constant nc; + if (expr->numeric_constant_value(&nc) + && nc.set_type(this->type_, false, this->location())) + { + Expression* e = nc.expression(this->location()); + return e->get_tree(context); + } + } + + tree const_tree = this->constant_->get_tree(gogo, context->function()); + if (this->type_ == NULL + || const_tree == error_mark_node + || TREE_TYPE(const_tree) == error_mark_node) + return const_tree; + + tree ret; + if (TYPE_MAIN_VARIANT(type_tree) == TYPE_MAIN_VARIANT(TREE_TYPE(const_tree))) + ret = fold_convert(type_tree, const_tree); + else if (TREE_CODE(type_tree) == INTEGER_TYPE) + ret = fold(convert_to_integer(type_tree, const_tree)); + else if (TREE_CODE(type_tree) == REAL_TYPE) + ret = fold(convert_to_real(type_tree, const_tree)); + else if (TREE_CODE(type_tree) == COMPLEX_TYPE) + ret = fold(convert_to_complex(type_tree, const_tree)); + else + go_unreachable(); + return ret; +} + +// Dump ast representation for constant expression. + +void +Const_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << this->constant_->name(); +} + +// Make a reference to a constant in an expression. + +Expression* +Expression::make_const_reference(Named_object* constant, + Location location) +{ + return new Const_expression(constant, location); +} + +// Find a named object in an expression. + +int +Find_named_object::expression(Expression** pexpr) +{ + switch ((*pexpr)->classification()) + { + case Expression::EXPRESSION_CONST_REFERENCE: + { + Const_expression* ce = static_cast<Const_expression*>(*pexpr); + if (ce->named_object() == this->no_) + break; + + // We need to check a constant initializer explicitly, as + // loops here will not be caught by the loop checking for + // variable initializers. + ce->check_for_init_loop(); + + return TRAVERSE_CONTINUE; + } + + case Expression::EXPRESSION_VAR_REFERENCE: + if ((*pexpr)->var_expression()->named_object() == this->no_) + break; + return TRAVERSE_CONTINUE; + case Expression::EXPRESSION_FUNC_REFERENCE: + if ((*pexpr)->func_expression()->named_object() == this->no_) + break; + return TRAVERSE_CONTINUE; + default: + return TRAVERSE_CONTINUE; + } + this->found_ = true; + return TRAVERSE_EXIT; +} + +// The nil value. + +class Nil_expression : public Expression +{ + public: + Nil_expression(Location location) + : Expression(EXPRESSION_NIL, location) + { } + + static Expression* + do_import(Import*); + + protected: + bool + do_is_constant() const + { return true; } + + bool + do_is_immutable() const + { return true; } + + Type* + do_type() + { return Type::make_nil_type(); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context*) + { return null_pointer_node; } + + void + do_export(Export* exp) const + { exp->write_c_string("nil"); } + + void + do_dump_expression(Ast_dump_context* ast_dump_context) const + { ast_dump_context->ostream() << "nil"; } +}; + +// Import a nil expression. + +Expression* +Nil_expression::do_import(Import* imp) +{ + imp->require_c_string("nil"); + return Expression::make_nil(imp->location()); +} + +// Make a nil expression. + +Expression* +Expression::make_nil(Location location) +{ + return new Nil_expression(location); +} + +// The value of the predeclared constant iota. This is little more +// than a marker. This will be lowered to an integer in +// Const_expression::do_lower, which is where we know the value that +// it should have. + +class Iota_expression : public Parser_expression +{ + public: + Iota_expression(Location location) + : Parser_expression(EXPRESSION_IOTA, location) + { } + + protected: + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int) + { go_unreachable(); } + + // There should only ever be one of these. + Expression* + do_copy() + { go_unreachable(); } + + void + do_dump_expression(Ast_dump_context* ast_dump_context) const + { ast_dump_context->ostream() << "iota"; } +}; + +// Make an iota expression. This is only called for one case: the +// value of the predeclared constant iota. + +Expression* +Expression::make_iota() +{ + static Iota_expression iota_expression(Linemap::unknown_location()); + return &iota_expression; +} + +// A type conversion expression. + +class Type_conversion_expression : public Expression +{ + public: + Type_conversion_expression(Type* type, Expression* expr, + Location location) + : Expression(EXPRESSION_CONVERSION, location), + type_(type), expr_(expr), may_convert_function_types_(false) + { } + + // Return the type to which we are converting. + Type* + type() const + { return this->type_; } + + // Return the expression which we are converting. + Expression* + expr() const + { return this->expr_; } + + // Permit converting from one function type to another. This is + // used internally for method expressions. + void + set_may_convert_function_types() + { + this->may_convert_function_types_ = true; + } + + // Import a type conversion expression. + static Expression* + do_import(Import*); + + protected: + int + do_traverse(Traverse* traverse); + + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int); + + Expression* + do_flatten(Gogo*, Named_object*, Statement_inserter*); + + bool + do_is_constant() const; + + bool + do_numeric_constant_value(Numeric_constant*) const; + + bool + do_string_constant_value(std::string*) const; + + Type* + do_type() + { return this->type_; } + + void + do_determine_type(const Type_context*) + { + Type_context subcontext(this->type_, false); + this->expr_->determine_type(&subcontext); + } + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return new Type_conversion_expression(this->type_, this->expr_->copy(), + this->location()); + } + + tree + do_get_tree(Translate_context* context); + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type to convert to. + Type* type_; + // The expression to convert. + Expression* expr_; + // True if this is permitted to convert function types. This is + // used internally for method expressions. + bool may_convert_function_types_; +}; + +// Traversal. + +int +Type_conversion_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT + || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Convert to a constant at lowering time. + +Expression* +Type_conversion_expression::do_lower(Gogo*, Named_object*, + Statement_inserter*, int) +{ + Type* type = this->type_; + Expression* val = this->expr_; + Location location = this->location(); + + if (type->is_numeric_type()) + { + Numeric_constant nc; + if (val->numeric_constant_value(&nc)) + { + if (!nc.set_type(type, true, location)) + return Expression::make_error(location); + return nc.expression(location); + } + } + + if (type->is_slice_type()) + { + Type* element_type = type->array_type()->element_type()->forwarded(); + bool is_byte = (element_type->integer_type() != NULL + && element_type->integer_type()->is_byte()); + bool is_rune = (element_type->integer_type() != NULL + && element_type->integer_type()->is_rune()); + if (is_byte || is_rune) + { + std::string s; + if (val->string_constant_value(&s)) + { + Expression_list* vals = new Expression_list(); + if (is_byte) + { + for (std::string::const_iterator p = s.begin(); + p != s.end(); + p++) + { + mpz_t val; + mpz_init_set_ui(val, static_cast<unsigned char>(*p)); + Expression* v = Expression::make_integer(&val, + element_type, + location); + vals->push_back(v); + mpz_clear(val); + } + } + else + { + const char *p = s.data(); + const char *pend = s.data() + s.length(); + while (p < pend) + { + unsigned int c; + int adv = Lex::fetch_char(p, &c); + if (adv == 0) + { + warning_at(this->location(), 0, + "invalid UTF-8 encoding"); + adv = 1; + } + p += adv; + mpz_t val; + mpz_init_set_ui(val, c); + Expression* v = Expression::make_integer(&val, + element_type, + location); + vals->push_back(v); + mpz_clear(val); + } + } + + return Expression::make_slice_composite_literal(type, vals, + location); + } + } + } + + return this; +} + +// Flatten a type conversion by using a temporary variable for the slice +// in slice to string conversions. + +Expression* +Type_conversion_expression::do_flatten(Gogo*, Named_object*, + Statement_inserter* inserter) +{ + if (this->type()->is_string_type() + && this->expr_->type()->is_slice_type() + && !this->expr_->is_variable()) + { + Temporary_statement* temp = + Statement::make_temporary(NULL, this->expr_, this->location()); + inserter->insert(temp); + this->expr_ = Expression::make_temporary_reference(temp, this->location()); + } + return this; +} + +// Return whether a type conversion is a constant. + +bool +Type_conversion_expression::do_is_constant() const +{ + if (!this->expr_->is_constant()) + return false; + + // A conversion to a type that may not be used as a constant is not + // a constant. For example, []byte(nil). + Type* type = this->type_; + if (type->integer_type() == NULL + && type->float_type() == NULL + && type->complex_type() == NULL + && !type->is_boolean_type() + && !type->is_string_type()) + return false; + + return true; +} + +// Return the constant numeric value if there is one. + +bool +Type_conversion_expression::do_numeric_constant_value( + Numeric_constant* nc) const +{ + if (!this->type_->is_numeric_type()) + return false; + if (!this->expr_->numeric_constant_value(nc)) + return false; + return nc->set_type(this->type_, false, this->location()); +} + +// Return the constant string value if there is one. + +bool +Type_conversion_expression::do_string_constant_value(std::string* val) const +{ + if (this->type_->is_string_type() + && this->expr_->type()->integer_type() != NULL) + { + Numeric_constant nc; + if (this->expr_->numeric_constant_value(&nc)) + { + unsigned long ival; + if (nc.to_unsigned_long(&ival) == Numeric_constant::NC_UL_VALID) + { + val->clear(); + Lex::append_char(ival, true, val, this->location()); + return true; + } + } + } + + // FIXME: Could handle conversion from const []int here. + + return false; +} + +// Check that types are convertible. + +void +Type_conversion_expression::do_check_types(Gogo*) +{ + Type* type = this->type_; + Type* expr_type = this->expr_->type(); + std::string reason; + + if (type->is_error() || expr_type->is_error()) + { + this->set_is_error(); + return; + } + + if (this->may_convert_function_types_ + && type->function_type() != NULL + && expr_type->function_type() != NULL) + return; + + if (Type::are_convertible(type, expr_type, &reason)) + return; + + error_at(this->location(), "%s", reason.c_str()); + this->set_is_error(); +} + +// Get a tree for a type conversion. + +tree +Type_conversion_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + tree type_tree = type_to_tree(this->type_->get_backend(gogo)); + tree expr_tree = this->expr_->get_tree(context); + + if (type_tree == error_mark_node + || expr_tree == error_mark_node + || TREE_TYPE(expr_tree) == error_mark_node) + return error_mark_node; + + if (TYPE_MAIN_VARIANT(type_tree) == TYPE_MAIN_VARIANT(TREE_TYPE(expr_tree))) + return fold_convert(type_tree, expr_tree); + + Type* type = this->type_; + Type* expr_type = this->expr_->type(); + tree ret; + if (type->interface_type() != NULL || expr_type->interface_type() != NULL) + ret = Expression::convert_for_assignment(context, type, expr_type, + expr_tree, this->location()); + else if (type->integer_type() != NULL) + { + if (expr_type->integer_type() != NULL + || expr_type->float_type() != NULL + || expr_type->is_unsafe_pointer_type()) + ret = fold(convert_to_integer(type_tree, expr_tree)); + else + go_unreachable(); + } + else if (type->float_type() != NULL) + { + if (expr_type->integer_type() != NULL + || expr_type->float_type() != NULL) + ret = fold(convert_to_real(type_tree, expr_tree)); + else + go_unreachable(); + } + else if (type->complex_type() != NULL) + { + if (expr_type->complex_type() != NULL) + ret = fold(convert_to_complex(type_tree, expr_tree)); + else + go_unreachable(); + } + else if (type->is_string_type() + && expr_type->integer_type() != NULL) + { + Type* int_type = Type::lookup_integer_type("int"); + tree int_type_tree = type_to_tree(int_type->get_backend(gogo)); + + expr_tree = fold_convert(int_type_tree, expr_tree); + if (tree_fits_shwi_p (expr_tree)) + { + HOST_WIDE_INT intval = tree_to_shwi (expr_tree); + std::string s; + Lex::append_char(intval, true, &s, this->location()); + Expression* se = Expression::make_string(s, this->location()); + return se->get_tree(context); + } + + Expression* i2s_expr = + Runtime::make_call(Runtime::INT_TO_STRING, this->location(), 1, + this->expr_); + i2s_expr = Expression::make_cast(type, i2s_expr, this->location()); + ret = i2s_expr->get_tree(context); + } + else if (type->is_string_type() && expr_type->is_slice_type()) + { + Location location = this->location(); + Array_type* a = expr_type->array_type(); + Type* e = a->element_type()->forwarded(); + go_assert(e->integer_type() != NULL); + go_assert(this->expr_->is_variable()); + + Runtime::Function code; + if (e->integer_type()->is_byte()) + code = Runtime::BYTE_ARRAY_TO_STRING; + else + { + go_assert(e->integer_type()->is_rune()); + code = Runtime::INT_ARRAY_TO_STRING; + } + Expression* valptr = a->get_value_pointer(gogo, this->expr_); + Expression* len = a->get_length(gogo, this->expr_); + Expression* a2s_expr = Runtime::make_call(code, location, 2, valptr, len); + ret = a2s_expr->get_tree(context); + } + else if (type->is_slice_type() && expr_type->is_string_type()) + { + Type* e = type->array_type()->element_type()->forwarded(); + go_assert(e->integer_type() != NULL); + + Expression* s2a_expr; + if (e->integer_type()->is_byte()) + s2a_expr = Runtime::make_call(Runtime::STRING_TO_BYTE_ARRAY, + this->location(), 1, this->expr_); + else + { + go_assert(e->integer_type()->is_rune()); + s2a_expr = Runtime::make_call(Runtime::STRING_TO_INT_ARRAY, + this->location(), 1, this->expr_); + } + s2a_expr = Expression::make_unsafe_cast(type, s2a_expr, + this->location()); + ret = s2a_expr->get_tree(context); + } + else if ((type->is_unsafe_pointer_type() + && expr_type->points_to() != NULL) + || (expr_type->is_unsafe_pointer_type() + && type->points_to() != NULL)) + ret = fold_convert(type_tree, expr_tree); + else if (type->is_unsafe_pointer_type() + && expr_type->integer_type() != NULL) + ret = convert_to_pointer(type_tree, expr_tree); + else if (this->may_convert_function_types_ + && type->function_type() != NULL + && expr_type->function_type() != NULL) + ret = fold_convert_loc(this->location().gcc_location(), type_tree, + expr_tree); + else + ret = Expression::convert_for_assignment(context, type, expr_type, + expr_tree, this->location()); + + return ret; +} + +// Output a type conversion in a constant expression. + +void +Type_conversion_expression::do_export(Export* exp) const +{ + exp->write_c_string("convert("); + exp->write_type(this->type_); + exp->write_c_string(", "); + this->expr_->export_expression(exp); + exp->write_c_string(")"); +} + +// Import a type conversion or a struct construction. + +Expression* +Type_conversion_expression::do_import(Import* imp) +{ + imp->require_c_string("convert("); + Type* type = imp->read_type(); + imp->require_c_string(", "); + Expression* val = Expression::import_expression(imp); + imp->require_c_string(")"); + return Expression::make_cast(type, val, imp->location()); +} + +// Dump ast representation for a type conversion expression. + +void +Type_conversion_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << "("; + ast_dump_context->dump_expression(this->expr_); + ast_dump_context->ostream() << ") "; +} + +// Make a type cast expression. + +Expression* +Expression::make_cast(Type* type, Expression* val, Location location) +{ + if (type->is_error_type() || val->is_error_expression()) + return Expression::make_error(location); + return new Type_conversion_expression(type, val, location); +} + +// An unsafe type conversion, used to pass values to builtin functions. + +class Unsafe_type_conversion_expression : public Expression +{ + public: + Unsafe_type_conversion_expression(Type* type, Expression* expr, + Location location) + : Expression(EXPRESSION_UNSAFE_CONVERSION, location), + type_(type), expr_(expr) + { } + + protected: + int + do_traverse(Traverse* traverse); + + Type* + do_type() + { return this->type_; } + + void + do_determine_type(const Type_context*) + { this->expr_->determine_type_no_context(); } + + Expression* + do_copy() + { + return new Unsafe_type_conversion_expression(this->type_, + this->expr_->copy(), + this->location()); + } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type to convert to. + Type* type_; + // The expression to convert. + Expression* expr_; +}; + +// Traversal. + +int +Unsafe_type_conversion_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT + || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Convert to backend representation. + +tree +Unsafe_type_conversion_expression::do_get_tree(Translate_context* context) +{ + // We are only called for a limited number of cases. + + Type* t = this->type_; + Type* et = this->expr_->type(); + + tree type_tree = type_to_tree(this->type_->get_backend(context->gogo())); + tree expr_tree = this->expr_->get_tree(context); + if (type_tree == error_mark_node || expr_tree == error_mark_node) + return error_mark_node; + + Location loc = this->location(); + + bool use_view_convert = false; + if (t->is_slice_type()) + { + go_assert(et->is_slice_type()); + use_view_convert = true; + } + else if (t->map_type() != NULL) + go_assert(et->map_type() != NULL); + else if (t->channel_type() != NULL) + go_assert(et->channel_type() != NULL); + else if (t->points_to() != NULL) + go_assert(et->points_to() != NULL || et->is_nil_type()); + else if (et->is_unsafe_pointer_type()) + go_assert(t->points_to() != NULL); + else if (t->interface_type() != NULL && !t->interface_type()->is_empty()) + { + go_assert(et->interface_type() != NULL + && !et->interface_type()->is_empty()); + use_view_convert = true; + } + else if (t->interface_type() != NULL && t->interface_type()->is_empty()) + { + go_assert(et->interface_type() != NULL + && et->interface_type()->is_empty()); + use_view_convert = true; + } + else if (t->integer_type() != NULL) + { + go_assert(et->is_boolean_type() + || et->integer_type() != NULL + || et->function_type() != NULL + || et->points_to() != NULL + || et->map_type() != NULL + || et->channel_type() != NULL); + return convert_to_integer(type_tree, expr_tree); + } + else + go_unreachable(); + + if (use_view_convert) + return fold_build1_loc(loc.gcc_location(), VIEW_CONVERT_EXPR, type_tree, + expr_tree); + else + return fold_convert_loc(loc.gcc_location(), type_tree, expr_tree); +} + +// Dump ast representation for an unsafe type conversion expression. + +void +Unsafe_type_conversion_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << "("; + ast_dump_context->dump_expression(this->expr_); + ast_dump_context->ostream() << ") "; +} + +// Make an unsafe type conversion expression. + +Expression* +Expression::make_unsafe_cast(Type* type, Expression* expr, + Location location) +{ + return new Unsafe_type_conversion_expression(type, expr, location); +} + +// Unary expressions. + +class Unary_expression : public Expression +{ + public: + Unary_expression(Operator op, Expression* expr, Location location) + : Expression(EXPRESSION_UNARY, location), + op_(op), escapes_(true), create_temp_(false), expr_(expr), + issue_nil_check_(false) + { } + + // Return the operator. + Operator + op() const + { return this->op_; } + + // Return the operand. + Expression* + operand() const + { return this->expr_; } + + // Record that an address expression does not escape. + void + set_does_not_escape() + { + go_assert(this->op_ == OPERATOR_AND); + this->escapes_ = false; + } + + // Record that this is an address expression which should create a + // temporary variable if necessary. This is used for method calls. + void + set_create_temp() + { + go_assert(this->op_ == OPERATOR_AND); + this->create_temp_ = true; + } + + // Apply unary opcode OP to UNC, setting NC. Return true if this + // could be done, false if not. Issue errors for overflow. + static bool + eval_constant(Operator op, const Numeric_constant* unc, + Location, Numeric_constant* nc); + + static Expression* + do_import(Import*); + + protected: + int + do_traverse(Traverse* traverse) + { return Expression::traverse(&this->expr_, traverse); } + + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int); + + Expression* + do_flatten(Gogo*, Named_object*, Statement_inserter*); + + bool + do_is_constant() const; + + bool + do_is_immutable() const + { return this->expr_->is_immutable(); } + + bool + do_numeric_constant_value(Numeric_constant*) const; + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return Expression::make_unary(this->op_, this->expr_->copy(), + this->location()); + } + + bool + do_must_eval_subexpressions_in_order(int*) const + { return this->op_ == OPERATOR_MULT; } + + bool + do_is_addressable() const + { return this->op_ == OPERATOR_MULT; } + + tree + do_get_tree(Translate_context*); + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + void + do_issue_nil_check() + { this->issue_nil_check_ = (this->op_ == OPERATOR_MULT); } + + private: + // The unary operator to apply. + Operator op_; + // Normally true. False if this is an address expression which does + // not escape the current function. + bool escapes_; + // True if this is an address expression which should create a + // temporary variable if necessary. + bool create_temp_; + // The operand. + Expression* expr_; + // Whether or not to issue a nil check for this expression if its address + // is being taken. + bool issue_nil_check_; +}; + +// If we are taking the address of a composite literal, and the +// contents are not constant, then we want to make a heap composite +// instead. + +Expression* +Unary_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int) +{ + Location loc = this->location(); + Operator op = this->op_; + Expression* expr = this->expr_; + + if (op == OPERATOR_MULT && expr->is_type_expression()) + return Expression::make_type(Type::make_pointer_type(expr->type()), loc); + + // *&x simplifies to x. *(*T)(unsafe.Pointer)(&x) does not require + // moving x to the heap. FIXME: Is it worth doing a real escape + // analysis here? This case is found in math/unsafe.go and is + // therefore worth special casing. + if (op == OPERATOR_MULT) + { + Expression* e = expr; + while (e->classification() == EXPRESSION_CONVERSION) + { + Type_conversion_expression* te + = static_cast<Type_conversion_expression*>(e); + e = te->expr(); + } + + if (e->classification() == EXPRESSION_UNARY) + { + Unary_expression* ue = static_cast<Unary_expression*>(e); + if (ue->op_ == OPERATOR_AND) + { + if (e == expr) + { + // *&x == x. + if (!ue->expr_->is_addressable() && !ue->create_temp_) + { + error_at(ue->location(), + "invalid operand for unary %<&%>"); + this->set_is_error(); + } + return ue->expr_; + } + ue->set_does_not_escape(); + } + } + } + + // Catching an invalid indirection of unsafe.Pointer here avoid + // having to deal with TYPE_VOID in other places. + if (op == OPERATOR_MULT && expr->type()->is_unsafe_pointer_type()) + { + error_at(this->location(), "invalid indirect of %<unsafe.Pointer%>"); + return Expression::make_error(this->location()); + } + + if (op == OPERATOR_PLUS || op == OPERATOR_MINUS || op == OPERATOR_XOR) + { + Numeric_constant nc; + if (expr->numeric_constant_value(&nc)) + { + Numeric_constant result; + if (Unary_expression::eval_constant(op, &nc, loc, &result)) + return result.expression(loc); + } + } + + return this; +} + +// Flatten expression if a nil check must be performed and create temporary +// variables if necessary. + +Expression* +Unary_expression::do_flatten(Gogo* gogo, Named_object*, + Statement_inserter* inserter) +{ + if (this->is_error_expression() || this->expr_->is_error_expression()) + return Expression::make_error(this->location()); + + Location location = this->location(); + if (this->op_ == OPERATOR_MULT + && !this->expr_->is_variable()) + { + go_assert(this->expr_->type()->points_to() != NULL); + Type* ptype = this->expr_->type()->points_to(); + if (!ptype->is_void_type()) + { + Btype* pbtype = ptype->get_backend(gogo); + size_t s = gogo->backend()->type_size(pbtype); + if (s >= 4096 || this->issue_nil_check_) + { + Temporary_statement* temp = + Statement::make_temporary(NULL, this->expr_, location); + inserter->insert(temp); + this->expr_ = + Expression::make_temporary_reference(temp, location); + } + } + } + + if (this->create_temp_ && !this->expr_->is_variable()) + { + Temporary_statement* temp = + Statement::make_temporary(NULL, this->expr_, location); + inserter->insert(temp); + this->expr_ = Expression::make_temporary_reference(temp, location); + } + + return this; +} + +// Return whether a unary expression is a constant. + +bool +Unary_expression::do_is_constant() const +{ + if (this->op_ == OPERATOR_MULT) + { + // Indirecting through a pointer is only constant if the object + // to which the expression points is constant, but we currently + // have no way to determine that. + return false; + } + else if (this->op_ == OPERATOR_AND) + { + // Taking the address of a variable is constant if it is a + // global variable, not constant otherwise. In other cases taking the + // address is probably not a constant. + Var_expression* ve = this->expr_->var_expression(); + if (ve != NULL) + { + Named_object* no = ve->named_object(); + return no->is_variable() && no->var_value()->is_global(); + } + return false; + } + else + return this->expr_->is_constant(); +} + +// Apply unary opcode OP to UNC, setting NC. Return true if this +// could be done, false if not. Issue errors for overflow. + +bool +Unary_expression::eval_constant(Operator op, const Numeric_constant* unc, + Location location, Numeric_constant* nc) +{ + switch (op) + { + case OPERATOR_PLUS: + *nc = *unc; + return true; + + case OPERATOR_MINUS: + if (unc->is_int() || unc->is_rune()) + break; + else if (unc->is_float()) + { + mpfr_t uval; + unc->get_float(&uval); + mpfr_t val; + mpfr_init(val); + mpfr_neg(val, uval, GMP_RNDN); + nc->set_float(unc->type(), val); + mpfr_clear(uval); + mpfr_clear(val); + return true; + } + else if (unc->is_complex()) + { + mpfr_t ureal, uimag; + unc->get_complex(&ureal, &uimag); + mpfr_t real, imag; + mpfr_init(real); + mpfr_init(imag); + mpfr_neg(real, ureal, GMP_RNDN); + mpfr_neg(imag, uimag, GMP_RNDN); + nc->set_complex(unc->type(), real, imag); + mpfr_clear(ureal); + mpfr_clear(uimag); + mpfr_clear(real); + mpfr_clear(imag); + return true; + } + else + go_unreachable(); + + case OPERATOR_XOR: + break; + + case OPERATOR_NOT: + case OPERATOR_AND: + case OPERATOR_MULT: + return false; + + default: + go_unreachable(); + } + + if (!unc->is_int() && !unc->is_rune()) + return false; + + mpz_t uval; + if (unc->is_rune()) + unc->get_rune(&uval); + else + unc->get_int(&uval); + mpz_t val; + mpz_init(val); + + switch (op) + { + case OPERATOR_MINUS: + mpz_neg(val, uval); + break; + + case OPERATOR_NOT: + mpz_set_ui(val, mpz_cmp_si(uval, 0) == 0 ? 1 : 0); + break; + + case OPERATOR_XOR: + { + Type* utype = unc->type(); + if (utype->integer_type() == NULL + || utype->integer_type()->is_abstract()) + mpz_com(val, uval); + else + { + // The number of HOST_WIDE_INTs that it takes to represent + // UVAL. + size_t count = ((mpz_sizeinbase(uval, 2) + + HOST_BITS_PER_WIDE_INT + - 1) + / HOST_BITS_PER_WIDE_INT); + + unsigned HOST_WIDE_INT* phwi = new unsigned HOST_WIDE_INT[count]; + memset(phwi, 0, count * sizeof(HOST_WIDE_INT)); + + size_t obits = utype->integer_type()->bits(); + + if (!utype->integer_type()->is_unsigned() && mpz_sgn(uval) < 0) + { + mpz_t adj; + mpz_init_set_ui(adj, 1); + mpz_mul_2exp(adj, adj, obits); + mpz_add(uval, uval, adj); + mpz_clear(adj); + } + + size_t ecount; + mpz_export(phwi, &ecount, -1, sizeof(HOST_WIDE_INT), 0, 0, uval); + go_assert(ecount <= count); + + // Trim down to the number of words required by the type. + size_t ocount = ((obits + HOST_BITS_PER_WIDE_INT - 1) + / HOST_BITS_PER_WIDE_INT); + go_assert(ocount <= count); + + for (size_t i = 0; i < ocount; ++i) + phwi[i] = ~phwi[i]; + + size_t clearbits = ocount * HOST_BITS_PER_WIDE_INT - obits; + if (clearbits != 0) + phwi[ocount - 1] &= (((unsigned HOST_WIDE_INT) (HOST_WIDE_INT) -1) + >> clearbits); + + mpz_import(val, ocount, -1, sizeof(HOST_WIDE_INT), 0, 0, phwi); + + if (!utype->integer_type()->is_unsigned() + && mpz_tstbit(val, obits - 1)) + { + mpz_t adj; + mpz_init_set_ui(adj, 1); + mpz_mul_2exp(adj, adj, obits); + mpz_sub(val, val, adj); + mpz_clear(adj); + } + + delete[] phwi; + } + } + break; + + default: + go_unreachable(); + } + + if (unc->is_rune()) + nc->set_rune(NULL, val); + else + nc->set_int(NULL, val); + + mpz_clear(uval); + mpz_clear(val); + + return nc->set_type(unc->type(), true, location); +} + +// Return the integral constant value of a unary expression, if it has one. + +bool +Unary_expression::do_numeric_constant_value(Numeric_constant* nc) const +{ + Numeric_constant unc; + if (!this->expr_->numeric_constant_value(&unc)) + return false; + return Unary_expression::eval_constant(this->op_, &unc, this->location(), + nc); +} + +// Return the type of a unary expression. + +Type* +Unary_expression::do_type() +{ + switch (this->op_) + { + case OPERATOR_PLUS: + case OPERATOR_MINUS: + case OPERATOR_NOT: + case OPERATOR_XOR: + return this->expr_->type(); + + case OPERATOR_AND: + return Type::make_pointer_type(this->expr_->type()); + + case OPERATOR_MULT: + { + Type* subtype = this->expr_->type(); + Type* points_to = subtype->points_to(); + if (points_to == NULL) + return Type::make_error_type(); + return points_to; + } + + default: + go_unreachable(); + } +} + +// Determine abstract types for a unary expression. + +void +Unary_expression::do_determine_type(const Type_context* context) +{ + switch (this->op_) + { + case OPERATOR_PLUS: + case OPERATOR_MINUS: + case OPERATOR_NOT: + case OPERATOR_XOR: + this->expr_->determine_type(context); + break; + + case OPERATOR_AND: + // Taking the address of something. + { + Type* subtype = (context->type == NULL + ? NULL + : context->type->points_to()); + Type_context subcontext(subtype, false); + this->expr_->determine_type(&subcontext); + } + break; + + case OPERATOR_MULT: + // Indirecting through a pointer. + { + Type* subtype = (context->type == NULL + ? NULL + : Type::make_pointer_type(context->type)); + Type_context subcontext(subtype, false); + this->expr_->determine_type(&subcontext); + } + break; + + default: + go_unreachable(); + } +} + +// Check types for a unary expression. + +void +Unary_expression::do_check_types(Gogo*) +{ + Type* type = this->expr_->type(); + if (type->is_error()) + { + this->set_is_error(); + return; + } + + switch (this->op_) + { + case OPERATOR_PLUS: + case OPERATOR_MINUS: + if (type->integer_type() == NULL + && type->float_type() == NULL + && type->complex_type() == NULL) + this->report_error(_("expected numeric type")); + break; + + case OPERATOR_NOT: + if (!type->is_boolean_type()) + this->report_error(_("expected boolean type")); + break; + + case OPERATOR_XOR: + if (type->integer_type() == NULL + && !type->is_boolean_type()) + this->report_error(_("expected integer or boolean type")); + break; + + case OPERATOR_AND: + if (!this->expr_->is_addressable()) + { + if (!this->create_temp_) + { + error_at(this->location(), "invalid operand for unary %<&%>"); + this->set_is_error(); + } + } + else + { + this->expr_->address_taken(this->escapes_); + this->expr_->issue_nil_check(); + } + break; + + case OPERATOR_MULT: + // Indirecting through a pointer. + if (type->points_to() == NULL) + this->report_error(_("expected pointer")); + break; + + default: + go_unreachable(); + } +} + +// Get a tree for a unary expression. + +tree +Unary_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Location loc = this->location(); + + // Taking the address of a set-and-use-temporary expression requires + // setting the temporary and then taking the address. + if (this->op_ == OPERATOR_AND) + { + Set_and_use_temporary_expression* sut = + this->expr_->set_and_use_temporary_expression(); + if (sut != NULL) + { + Temporary_statement* temp = sut->temporary(); + Bvariable* bvar = temp->get_backend_variable(context); + Bexpression* bvar_expr = gogo->backend()->var_expression(bvar, loc); + + Expression* val = sut->expression(); + Bexpression* bval = tree_to_expr(val->get_tree(context)); + + Bstatement* bassign = + gogo->backend()->assignment_statement(bvar_expr, bval, loc); + Bexpression* bvar_addr = + gogo->backend()->address_expression(bvar_expr, loc); + Bexpression* ret = + gogo->backend()->compound_expression(bassign, bvar_addr, loc); + return expr_to_tree(ret); + } + } + + Bexpression* ret; + tree expr = this->expr_->get_tree(context); + Bexpression* bexpr = tree_to_expr(expr); + Btype* btype = this->expr_->type()->get_backend(gogo); + switch (this->op_) + { + case OPERATOR_PLUS: + ret = bexpr; + break; + + case OPERATOR_MINUS: + ret = gogo->backend()->unary_expression(this->op_, bexpr, loc); + ret = gogo->backend()->convert_expression(btype, ret, loc); + break; + + case OPERATOR_NOT: + case OPERATOR_XOR: + ret = gogo->backend()->unary_expression(this->op_, bexpr, loc); + break; + + case OPERATOR_AND: + if (!this->create_temp_) + { + // We should not see a non-constant constructor here; cases + // where we would see one should have been moved onto the + // heap at parse time. Taking the address of a nonconstant + // constructor will not do what the programmer expects. + + go_assert(!this->expr_->is_composite_literal() + || this->expr_->is_immutable()); + Unary_expression* ue = static_cast<Unary_expression*>(this->expr_); + go_assert(ue == NULL || ue->op() != OPERATOR_AND); + } + + // Build a decl for a constant constructor. + if ((this->expr_->is_composite_literal() + || this->expr_->string_expression() != NULL) + && this->expr_->is_immutable()) + { + static unsigned int counter; + char buf[100]; + snprintf(buf, sizeof buf, "C%u", counter); + ++counter; + + Bvariable* decl = + gogo->backend()->immutable_struct(buf, true, false, btype, loc); + gogo->backend()->immutable_struct_set_init(decl, buf, true, false, + btype, loc, bexpr); + bexpr = gogo->backend()->var_expression(decl, loc); + } + + go_assert(!this->create_temp_ || this->expr_->is_variable()); + ret = gogo->backend()->address_expression(bexpr, loc); + break; + + case OPERATOR_MULT: + { + go_assert(this->expr_->type()->points_to() != NULL); + + // If we are dereferencing the pointer to a large struct, we + // need to check for nil. We don't bother to check for small + // structs because we expect the system to crash on a nil + // pointer dereference. However, if we know the address of this + // expression is being taken, we must always check for nil. + + Type* ptype = this->expr_->type()->points_to(); + Btype* pbtype = ptype->get_backend(gogo); + if (!ptype->is_void_type()) + { + size_t s = gogo->backend()->type_size(pbtype); + if (s >= 4096 || this->issue_nil_check_) + { + go_assert(this->expr_->is_variable()); + + Expression* nil_expr = Expression::make_nil(loc); + Bexpression* nil = tree_to_expr(nil_expr->get_tree(context)); + Bexpression* compare = + gogo->backend()->binary_expression(OPERATOR_EQEQ, bexpr, + nil, loc); + + Expression* crash_expr = + gogo->runtime_error(RUNTIME_ERROR_NIL_DEREFERENCE, loc); + Bexpression* crash = + tree_to_expr(crash_expr->get_tree(context)); + bexpr = gogo->backend()->conditional_expression(btype, compare, + crash, bexpr, + loc); + + } + } + + // If the type of EXPR is a recursive pointer type, then we + // need to insert a cast before indirecting. + tree expr = expr_to_tree(bexpr); + tree target_type_tree = TREE_TYPE(TREE_TYPE(expr)); + if (VOID_TYPE_P(target_type_tree)) + { + tree ind = type_to_tree(pbtype); + expr = fold_convert_loc(loc.gcc_location(), + build_pointer_type(ind), expr); + bexpr = tree_to_expr(expr); + } + + ret = gogo->backend()->indirect_expression(bexpr, false, loc); + } + break; + + default: + go_unreachable(); + } + + return expr_to_tree(ret); +} + +// Export a unary expression. + +void +Unary_expression::do_export(Export* exp) const +{ + switch (this->op_) + { + case OPERATOR_PLUS: + exp->write_c_string("+ "); + break; + case OPERATOR_MINUS: + exp->write_c_string("- "); + break; + case OPERATOR_NOT: + exp->write_c_string("! "); + break; + case OPERATOR_XOR: + exp->write_c_string("^ "); + break; + case OPERATOR_AND: + case OPERATOR_MULT: + default: + go_unreachable(); + } + this->expr_->export_expression(exp); +} + +// Import a unary expression. + +Expression* +Unary_expression::do_import(Import* imp) +{ + Operator op; + switch (imp->get_char()) + { + case '+': + op = OPERATOR_PLUS; + break; + case '-': + op = OPERATOR_MINUS; + break; + case '!': + op = OPERATOR_NOT; + break; + case '^': + op = OPERATOR_XOR; + break; + default: + go_unreachable(); + } + imp->require_c_string(" "); + Expression* expr = Expression::import_expression(imp); + return Expression::make_unary(op, expr, imp->location()); +} + +// Dump ast representation of an unary expression. + +void +Unary_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_operator(this->op_); + ast_dump_context->ostream() << "("; + ast_dump_context->dump_expression(this->expr_); + ast_dump_context->ostream() << ") "; +} + +// Make a unary expression. + +Expression* +Expression::make_unary(Operator op, Expression* expr, Location location) +{ + return new Unary_expression(op, expr, location); +} + +// If this is an indirection through a pointer, return the expression +// being pointed through. Otherwise return this. + +Expression* +Expression::deref() +{ + if (this->classification_ == EXPRESSION_UNARY) + { + Unary_expression* ue = static_cast<Unary_expression*>(this); + if (ue->op() == OPERATOR_MULT) + return ue->operand(); + } + return this; +} + +// Class Binary_expression. + +// Traversal. + +int +Binary_expression::do_traverse(Traverse* traverse) +{ + int t = Expression::traverse(&this->left_, traverse); + if (t == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return Expression::traverse(&this->right_, traverse); +} + +// Return the type to use for a binary operation on operands of +// LEFT_TYPE and RIGHT_TYPE. These are the types of constants and as +// such may be NULL or abstract. + +bool +Binary_expression::operation_type(Operator op, Type* left_type, + Type* right_type, Type** result_type) +{ + if (left_type != right_type + && !left_type->is_abstract() + && !right_type->is_abstract() + && left_type->base() != right_type->base() + && op != OPERATOR_LSHIFT + && op != OPERATOR_RSHIFT) + { + // May be a type error--let it be diagnosed elsewhere. + return false; + } + + if (op == OPERATOR_LSHIFT || op == OPERATOR_RSHIFT) + { + if (left_type->integer_type() != NULL) + *result_type = left_type; + else + *result_type = Type::make_abstract_integer_type(); + } + else if (!left_type->is_abstract() && left_type->named_type() != NULL) + *result_type = left_type; + else if (!right_type->is_abstract() && right_type->named_type() != NULL) + *result_type = right_type; + else if (!left_type->is_abstract()) + *result_type = left_type; + else if (!right_type->is_abstract()) + *result_type = right_type; + else if (left_type->complex_type() != NULL) + *result_type = left_type; + else if (right_type->complex_type() != NULL) + *result_type = right_type; + else if (left_type->float_type() != NULL) + *result_type = left_type; + else if (right_type->float_type() != NULL) + *result_type = right_type; + else if (left_type->integer_type() != NULL + && left_type->integer_type()->is_rune()) + *result_type = left_type; + else if (right_type->integer_type() != NULL + && right_type->integer_type()->is_rune()) + *result_type = right_type; + else + *result_type = left_type; + + return true; +} + +// Convert an integer comparison code and an operator to a boolean +// value. + +bool +Binary_expression::cmp_to_bool(Operator op, int cmp) +{ + switch (op) + { + case OPERATOR_EQEQ: + return cmp == 0; + break; + case OPERATOR_NOTEQ: + return cmp != 0; + break; + case OPERATOR_LT: + return cmp < 0; + break; + case OPERATOR_LE: + return cmp <= 0; + case OPERATOR_GT: + return cmp > 0; + case OPERATOR_GE: + return cmp >= 0; + default: + go_unreachable(); + } +} + +// Compare constants according to OP. + +bool +Binary_expression::compare_constant(Operator op, Numeric_constant* left_nc, + Numeric_constant* right_nc, + Location location, bool* result) +{ + Type* left_type = left_nc->type(); + Type* right_type = right_nc->type(); + + Type* type; + if (!Binary_expression::operation_type(op, left_type, right_type, &type)) + return false; + + // When comparing an untyped operand to a typed operand, we are + // effectively coercing the untyped operand to the other operand's + // type, so make sure that is valid. + if (!left_nc->set_type(type, true, location) + || !right_nc->set_type(type, true, location)) + return false; + + bool ret; + int cmp; + if (type->complex_type() != NULL) + { + if (op != OPERATOR_EQEQ && op != OPERATOR_NOTEQ) + return false; + ret = Binary_expression::compare_complex(left_nc, right_nc, &cmp); + } + else if (type->float_type() != NULL) + ret = Binary_expression::compare_float(left_nc, right_nc, &cmp); + else + ret = Binary_expression::compare_integer(left_nc, right_nc, &cmp); + + if (ret) + *result = Binary_expression::cmp_to_bool(op, cmp); + + return ret; +} + +// Compare integer constants. + +bool +Binary_expression::compare_integer(const Numeric_constant* left_nc, + const Numeric_constant* right_nc, + int* cmp) +{ + mpz_t left_val; + if (!left_nc->to_int(&left_val)) + return false; + mpz_t right_val; + if (!right_nc->to_int(&right_val)) + { + mpz_clear(left_val); + return false; + } + + *cmp = mpz_cmp(left_val, right_val); + + mpz_clear(left_val); + mpz_clear(right_val); + + return true; +} + +// Compare floating point constants. + +bool +Binary_expression::compare_float(const Numeric_constant* left_nc, + const Numeric_constant* right_nc, + int* cmp) +{ + mpfr_t left_val; + if (!left_nc->to_float(&left_val)) + return false; + mpfr_t right_val; + if (!right_nc->to_float(&right_val)) + { + mpfr_clear(left_val); + return false; + } + + // We already coerced both operands to the same type. If that type + // is not an abstract type, we need to round the values accordingly. + Type* type = left_nc->type(); + if (!type->is_abstract() && type->float_type() != NULL) + { + int bits = type->float_type()->bits(); + mpfr_prec_round(left_val, bits, GMP_RNDN); + mpfr_prec_round(right_val, bits, GMP_RNDN); + } + + *cmp = mpfr_cmp(left_val, right_val); + + mpfr_clear(left_val); + mpfr_clear(right_val); + + return true; +} + +// Compare complex constants. Complex numbers may only be compared +// for equality. + +bool +Binary_expression::compare_complex(const Numeric_constant* left_nc, + const Numeric_constant* right_nc, + int* cmp) +{ + mpfr_t left_real, left_imag; + if (!left_nc->to_complex(&left_real, &left_imag)) + return false; + mpfr_t right_real, right_imag; + if (!right_nc->to_complex(&right_real, &right_imag)) + { + mpfr_clear(left_real); + mpfr_clear(left_imag); + return false; + } + + // We already coerced both operands to the same type. If that type + // is not an abstract type, we need to round the values accordingly. + Type* type = left_nc->type(); + if (!type->is_abstract() && type->complex_type() != NULL) + { + int bits = type->complex_type()->bits(); + mpfr_prec_round(left_real, bits / 2, GMP_RNDN); + mpfr_prec_round(left_imag, bits / 2, GMP_RNDN); + mpfr_prec_round(right_real, bits / 2, GMP_RNDN); + mpfr_prec_round(right_imag, bits / 2, GMP_RNDN); + } + + *cmp = (mpfr_cmp(left_real, right_real) != 0 + || mpfr_cmp(left_imag, right_imag) != 0); + + mpfr_clear(left_real); + mpfr_clear(left_imag); + mpfr_clear(right_real); + mpfr_clear(right_imag); + + return true; +} + +// Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC. Return +// true if this could be done, false if not. Issue errors at LOCATION +// as appropriate. + +bool +Binary_expression::eval_constant(Operator op, Numeric_constant* left_nc, + Numeric_constant* right_nc, + Location location, Numeric_constant* nc) +{ + switch (op) + { + case OPERATOR_OROR: + case OPERATOR_ANDAND: + case OPERATOR_EQEQ: + case OPERATOR_NOTEQ: + case OPERATOR_LT: + case OPERATOR_LE: + case OPERATOR_GT: + case OPERATOR_GE: + // These return boolean values, not numeric. + return false; + default: + break; + } + + Type* left_type = left_nc->type(); + Type* right_type = right_nc->type(); + + Type* type; + if (!Binary_expression::operation_type(op, left_type, right_type, &type)) + return false; + + bool is_shift = op == OPERATOR_LSHIFT || op == OPERATOR_RSHIFT; + + // When combining an untyped operand with a typed operand, we are + // effectively coercing the untyped operand to the other operand's + // type, so make sure that is valid. + if (!left_nc->set_type(type, true, location)) + return false; + if (!is_shift && !right_nc->set_type(type, true, location)) + return false; + + bool r; + if (type->complex_type() != NULL) + r = Binary_expression::eval_complex(op, left_nc, right_nc, location, nc); + else if (type->float_type() != NULL) + r = Binary_expression::eval_float(op, left_nc, right_nc, location, nc); + else + r = Binary_expression::eval_integer(op, left_nc, right_nc, location, nc); + + if (r) + r = nc->set_type(type, true, location); + + return r; +} + +// Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC, using +// integer operations. Return true if this could be done, false if +// not. + +bool +Binary_expression::eval_integer(Operator op, const Numeric_constant* left_nc, + const Numeric_constant* right_nc, + Location location, Numeric_constant* nc) +{ + mpz_t left_val; + if (!left_nc->to_int(&left_val)) + return false; + mpz_t right_val; + if (!right_nc->to_int(&right_val)) + { + mpz_clear(left_val); + return false; + } + + mpz_t val; + mpz_init(val); + + switch (op) + { + case OPERATOR_PLUS: + mpz_add(val, left_val, right_val); + break; + case OPERATOR_MINUS: + mpz_sub(val, left_val, right_val); + break; + case OPERATOR_OR: + mpz_ior(val, left_val, right_val); + break; + case OPERATOR_XOR: + mpz_xor(val, left_val, right_val); + break; + case OPERATOR_MULT: + mpz_mul(val, left_val, right_val); + break; + case OPERATOR_DIV: + if (mpz_sgn(right_val) != 0) + mpz_tdiv_q(val, left_val, right_val); + else + { + error_at(location, "division by zero"); + mpz_set_ui(val, 0); + } + break; + case OPERATOR_MOD: + if (mpz_sgn(right_val) != 0) + mpz_tdiv_r(val, left_val, right_val); + else + { + error_at(location, "division by zero"); + mpz_set_ui(val, 0); + } + break; + case OPERATOR_LSHIFT: + { + unsigned long shift = mpz_get_ui(right_val); + if (mpz_cmp_ui(right_val, shift) == 0 && shift <= 0x100000) + mpz_mul_2exp(val, left_val, shift); + else + { + error_at(location, "shift count overflow"); + mpz_set_ui(val, 0); + } + break; + } + break; + case OPERATOR_RSHIFT: + { + unsigned long shift = mpz_get_ui(right_val); + if (mpz_cmp_ui(right_val, shift) != 0) + { + error_at(location, "shift count overflow"); + mpz_set_ui(val, 0); + } + else + { + if (mpz_cmp_ui(left_val, 0) >= 0) + mpz_tdiv_q_2exp(val, left_val, shift); + else + mpz_fdiv_q_2exp(val, left_val, shift); + } + break; + } + break; + case OPERATOR_AND: + mpz_and(val, left_val, right_val); + break; + case OPERATOR_BITCLEAR: + { + mpz_t tval; + mpz_init(tval); + mpz_com(tval, right_val); + mpz_and(val, left_val, tval); + mpz_clear(tval); + } + break; + default: + go_unreachable(); + } + + mpz_clear(left_val); + mpz_clear(right_val); + + if (left_nc->is_rune() + || (op != OPERATOR_LSHIFT + && op != OPERATOR_RSHIFT + && right_nc->is_rune())) + nc->set_rune(NULL, val); + else + nc->set_int(NULL, val); + + mpz_clear(val); + + return true; +} + +// Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC, using +// floating point operations. Return true if this could be done, +// false if not. + +bool +Binary_expression::eval_float(Operator op, const Numeric_constant* left_nc, + const Numeric_constant* right_nc, + Location location, Numeric_constant* nc) +{ + mpfr_t left_val; + if (!left_nc->to_float(&left_val)) + return false; + mpfr_t right_val; + if (!right_nc->to_float(&right_val)) + { + mpfr_clear(left_val); + return false; + } + + mpfr_t val; + mpfr_init(val); + + bool ret = true; + switch (op) + { + case OPERATOR_PLUS: + mpfr_add(val, left_val, right_val, GMP_RNDN); + break; + case OPERATOR_MINUS: + mpfr_sub(val, left_val, right_val, GMP_RNDN); + break; + case OPERATOR_OR: + case OPERATOR_XOR: + case OPERATOR_AND: + case OPERATOR_BITCLEAR: + case OPERATOR_MOD: + case OPERATOR_LSHIFT: + case OPERATOR_RSHIFT: + mpfr_set_ui(val, 0, GMP_RNDN); + ret = false; + break; + case OPERATOR_MULT: + mpfr_mul(val, left_val, right_val, GMP_RNDN); + break; + case OPERATOR_DIV: + if (!mpfr_zero_p(right_val)) + mpfr_div(val, left_val, right_val, GMP_RNDN); + else + { + error_at(location, "division by zero"); + mpfr_set_ui(val, 0, GMP_RNDN); + } + break; + default: + go_unreachable(); + } + + mpfr_clear(left_val); + mpfr_clear(right_val); + + nc->set_float(NULL, val); + mpfr_clear(val); + + return ret; +} + +// Apply binary opcode OP to LEFT_NC and RIGHT_NC, setting NC, using +// complex operations. Return true if this could be done, false if +// not. + +bool +Binary_expression::eval_complex(Operator op, const Numeric_constant* left_nc, + const Numeric_constant* right_nc, + Location location, Numeric_constant* nc) +{ + mpfr_t left_real, left_imag; + if (!left_nc->to_complex(&left_real, &left_imag)) + return false; + mpfr_t right_real, right_imag; + if (!right_nc->to_complex(&right_real, &right_imag)) + { + mpfr_clear(left_real); + mpfr_clear(left_imag); + return false; + } + + mpfr_t real, imag; + mpfr_init(real); + mpfr_init(imag); + + bool ret = true; + switch (op) + { + case OPERATOR_PLUS: + mpfr_add(real, left_real, right_real, GMP_RNDN); + mpfr_add(imag, left_imag, right_imag, GMP_RNDN); + break; + case OPERATOR_MINUS: + mpfr_sub(real, left_real, right_real, GMP_RNDN); + mpfr_sub(imag, left_imag, right_imag, GMP_RNDN); + break; + case OPERATOR_OR: + case OPERATOR_XOR: + case OPERATOR_AND: + case OPERATOR_BITCLEAR: + case OPERATOR_MOD: + case OPERATOR_LSHIFT: + case OPERATOR_RSHIFT: + mpfr_set_ui(real, 0, GMP_RNDN); + mpfr_set_ui(imag, 0, GMP_RNDN); + ret = false; + break; + case OPERATOR_MULT: + { + // You might think that multiplying two complex numbers would + // be simple, and you would be right, until you start to think + // about getting the right answer for infinity. If one + // operand here is infinity and the other is anything other + // than zero or NaN, then we are going to wind up subtracting + // two infinity values. That will give us a NaN, but the + // correct answer is infinity. + + mpfr_t lrrr; + mpfr_init(lrrr); + mpfr_mul(lrrr, left_real, right_real, GMP_RNDN); + + mpfr_t lrri; + mpfr_init(lrri); + mpfr_mul(lrri, left_real, right_imag, GMP_RNDN); + + mpfr_t lirr; + mpfr_init(lirr); + mpfr_mul(lirr, left_imag, right_real, GMP_RNDN); + + mpfr_t liri; + mpfr_init(liri); + mpfr_mul(liri, left_imag, right_imag, GMP_RNDN); + + mpfr_sub(real, lrrr, liri, GMP_RNDN); + mpfr_add(imag, lrri, lirr, GMP_RNDN); + + // If we get NaN on both sides, check whether it should really + // be infinity. The rule is that if either side of the + // complex number is infinity, then the whole value is + // infinity, even if the other side is NaN. So the only case + // we have to fix is the one in which both sides are NaN. + if (mpfr_nan_p(real) && mpfr_nan_p(imag) + && (!mpfr_nan_p(left_real) || !mpfr_nan_p(left_imag)) + && (!mpfr_nan_p(right_real) || !mpfr_nan_p(right_imag))) + { + bool is_infinity = false; + + mpfr_t lr; + mpfr_t li; + mpfr_init_set(lr, left_real, GMP_RNDN); + mpfr_init_set(li, left_imag, GMP_RNDN); + + mpfr_t rr; + mpfr_t ri; + mpfr_init_set(rr, right_real, GMP_RNDN); + mpfr_init_set(ri, right_imag, GMP_RNDN); + + // If the left side is infinity, then the result is + // infinity. + if (mpfr_inf_p(lr) || mpfr_inf_p(li)) + { + mpfr_set_ui(lr, mpfr_inf_p(lr) ? 1 : 0, GMP_RNDN); + mpfr_copysign(lr, lr, left_real, GMP_RNDN); + mpfr_set_ui(li, mpfr_inf_p(li) ? 1 : 0, GMP_RNDN); + mpfr_copysign(li, li, left_imag, GMP_RNDN); + if (mpfr_nan_p(rr)) + { + mpfr_set_ui(rr, 0, GMP_RNDN); + mpfr_copysign(rr, rr, right_real, GMP_RNDN); + } + if (mpfr_nan_p(ri)) + { + mpfr_set_ui(ri, 0, GMP_RNDN); + mpfr_copysign(ri, ri, right_imag, GMP_RNDN); + } + is_infinity = true; + } + + // If the right side is infinity, then the result is + // infinity. + if (mpfr_inf_p(rr) || mpfr_inf_p(ri)) + { + mpfr_set_ui(rr, mpfr_inf_p(rr) ? 1 : 0, GMP_RNDN); + mpfr_copysign(rr, rr, right_real, GMP_RNDN); + mpfr_set_ui(ri, mpfr_inf_p(ri) ? 1 : 0, GMP_RNDN); + mpfr_copysign(ri, ri, right_imag, GMP_RNDN); + if (mpfr_nan_p(lr)) + { + mpfr_set_ui(lr, 0, GMP_RNDN); + mpfr_copysign(lr, lr, left_real, GMP_RNDN); + } + if (mpfr_nan_p(li)) + { + mpfr_set_ui(li, 0, GMP_RNDN); + mpfr_copysign(li, li, left_imag, GMP_RNDN); + } + is_infinity = true; + } + + // If we got an overflow in the intermediate computations, + // then the result is infinity. + if (!is_infinity + && (mpfr_inf_p(lrrr) || mpfr_inf_p(lrri) + || mpfr_inf_p(lirr) || mpfr_inf_p(liri))) + { + if (mpfr_nan_p(lr)) + { + mpfr_set_ui(lr, 0, GMP_RNDN); + mpfr_copysign(lr, lr, left_real, GMP_RNDN); + } + if (mpfr_nan_p(li)) + { + mpfr_set_ui(li, 0, GMP_RNDN); + mpfr_copysign(li, li, left_imag, GMP_RNDN); + } + if (mpfr_nan_p(rr)) + { + mpfr_set_ui(rr, 0, GMP_RNDN); + mpfr_copysign(rr, rr, right_real, GMP_RNDN); + } + if (mpfr_nan_p(ri)) + { + mpfr_set_ui(ri, 0, GMP_RNDN); + mpfr_copysign(ri, ri, right_imag, GMP_RNDN); + } + is_infinity = true; + } + + if (is_infinity) + { + mpfr_mul(lrrr, lr, rr, GMP_RNDN); + mpfr_mul(lrri, lr, ri, GMP_RNDN); + mpfr_mul(lirr, li, rr, GMP_RNDN); + mpfr_mul(liri, li, ri, GMP_RNDN); + mpfr_sub(real, lrrr, liri, GMP_RNDN); + mpfr_add(imag, lrri, lirr, GMP_RNDN); + mpfr_set_inf(real, mpfr_sgn(real)); + mpfr_set_inf(imag, mpfr_sgn(imag)); + } + + mpfr_clear(lr); + mpfr_clear(li); + mpfr_clear(rr); + mpfr_clear(ri); + } + + mpfr_clear(lrrr); + mpfr_clear(lrri); + mpfr_clear(lirr); + mpfr_clear(liri); + } + break; + case OPERATOR_DIV: + { + // For complex division we want to avoid having an + // intermediate overflow turn the whole result in a NaN. We + // scale the values to try to avoid this. + + if (mpfr_zero_p(right_real) && mpfr_zero_p(right_imag)) + { + error_at(location, "division by zero"); + mpfr_set_ui(real, 0, GMP_RNDN); + mpfr_set_ui(imag, 0, GMP_RNDN); + break; + } + + mpfr_t rra; + mpfr_t ria; + mpfr_init(rra); + mpfr_init(ria); + mpfr_abs(rra, right_real, GMP_RNDN); + mpfr_abs(ria, right_imag, GMP_RNDN); + mpfr_t t; + mpfr_init(t); + mpfr_max(t, rra, ria, GMP_RNDN); + + mpfr_t rr; + mpfr_t ri; + mpfr_init_set(rr, right_real, GMP_RNDN); + mpfr_init_set(ri, right_imag, GMP_RNDN); + long ilogbw = 0; + if (!mpfr_inf_p(t) && !mpfr_nan_p(t) && !mpfr_zero_p(t)) + { + ilogbw = mpfr_get_exp(t); + mpfr_mul_2si(rr, rr, - ilogbw, GMP_RNDN); + mpfr_mul_2si(ri, ri, - ilogbw, GMP_RNDN); + } + + mpfr_t denom; + mpfr_init(denom); + mpfr_mul(denom, rr, rr, GMP_RNDN); + mpfr_mul(t, ri, ri, GMP_RNDN); + mpfr_add(denom, denom, t, GMP_RNDN); + + mpfr_mul(real, left_real, rr, GMP_RNDN); + mpfr_mul(t, left_imag, ri, GMP_RNDN); + mpfr_add(real, real, t, GMP_RNDN); + mpfr_div(real, real, denom, GMP_RNDN); + mpfr_mul_2si(real, real, - ilogbw, GMP_RNDN); + + mpfr_mul(imag, left_imag, rr, GMP_RNDN); + mpfr_mul(t, left_real, ri, GMP_RNDN); + mpfr_sub(imag, imag, t, GMP_RNDN); + mpfr_div(imag, imag, denom, GMP_RNDN); + mpfr_mul_2si(imag, imag, - ilogbw, GMP_RNDN); + + // If we wind up with NaN on both sides, check whether we + // should really have infinity. The rule is that if either + // side of the complex number is infinity, then the whole + // value is infinity, even if the other side is NaN. So the + // only case we have to fix is the one in which both sides are + // NaN. + if (mpfr_nan_p(real) && mpfr_nan_p(imag) + && (!mpfr_nan_p(left_real) || !mpfr_nan_p(left_imag)) + && (!mpfr_nan_p(right_real) || !mpfr_nan_p(right_imag))) + { + if (mpfr_zero_p(denom)) + { + mpfr_set_inf(real, mpfr_sgn(rr)); + mpfr_mul(real, real, left_real, GMP_RNDN); + mpfr_set_inf(imag, mpfr_sgn(rr)); + mpfr_mul(imag, imag, left_imag, GMP_RNDN); + } + else if ((mpfr_inf_p(left_real) || mpfr_inf_p(left_imag)) + && mpfr_number_p(rr) && mpfr_number_p(ri)) + { + mpfr_set_ui(t, mpfr_inf_p(left_real) ? 1 : 0, GMP_RNDN); + mpfr_copysign(t, t, left_real, GMP_RNDN); + + mpfr_t t2; + mpfr_init_set_ui(t2, mpfr_inf_p(left_imag) ? 1 : 0, GMP_RNDN); + mpfr_copysign(t2, t2, left_imag, GMP_RNDN); + + mpfr_t t3; + mpfr_init(t3); + mpfr_mul(t3, t, rr, GMP_RNDN); + + mpfr_t t4; + mpfr_init(t4); + mpfr_mul(t4, t2, ri, GMP_RNDN); + + mpfr_add(t3, t3, t4, GMP_RNDN); + mpfr_set_inf(real, mpfr_sgn(t3)); + + mpfr_mul(t3, t2, rr, GMP_RNDN); + mpfr_mul(t4, t, ri, GMP_RNDN); + mpfr_sub(t3, t3, t4, GMP_RNDN); + mpfr_set_inf(imag, mpfr_sgn(t3)); + + mpfr_clear(t2); + mpfr_clear(t3); + mpfr_clear(t4); + } + else if ((mpfr_inf_p(right_real) || mpfr_inf_p(right_imag)) + && mpfr_number_p(left_real) && mpfr_number_p(left_imag)) + { + mpfr_set_ui(t, mpfr_inf_p(rr) ? 1 : 0, GMP_RNDN); + mpfr_copysign(t, t, rr, GMP_RNDN); + + mpfr_t t2; + mpfr_init_set_ui(t2, mpfr_inf_p(ri) ? 1 : 0, GMP_RNDN); + mpfr_copysign(t2, t2, ri, GMP_RNDN); + + mpfr_t t3; + mpfr_init(t3); + mpfr_mul(t3, left_real, t, GMP_RNDN); + + mpfr_t t4; + mpfr_init(t4); + mpfr_mul(t4, left_imag, t2, GMP_RNDN); + + mpfr_add(t3, t3, t4, GMP_RNDN); + mpfr_set_ui(real, 0, GMP_RNDN); + mpfr_mul(real, real, t3, GMP_RNDN); + + mpfr_mul(t3, left_imag, t, GMP_RNDN); + mpfr_mul(t4, left_real, t2, GMP_RNDN); + mpfr_sub(t3, t3, t4, GMP_RNDN); + mpfr_set_ui(imag, 0, GMP_RNDN); + mpfr_mul(imag, imag, t3, GMP_RNDN); + + mpfr_clear(t2); + mpfr_clear(t3); + mpfr_clear(t4); + } + } + + mpfr_clear(denom); + mpfr_clear(rr); + mpfr_clear(ri); + mpfr_clear(t); + mpfr_clear(rra); + mpfr_clear(ria); + } + break; + default: + go_unreachable(); + } + + mpfr_clear(left_real); + mpfr_clear(left_imag); + mpfr_clear(right_real); + mpfr_clear(right_imag); + + nc->set_complex(NULL, real, imag); + mpfr_clear(real); + mpfr_clear(imag); + + return ret; +} + +// Lower a binary expression. We have to evaluate constant +// expressions now, in order to implement Go's unlimited precision +// constants. + +Expression* +Binary_expression::do_lower(Gogo* gogo, Named_object*, + Statement_inserter* inserter, int) +{ + Location location = this->location(); + Operator op = this->op_; + Expression* left = this->left_; + Expression* right = this->right_; + + const bool is_comparison = (op == OPERATOR_EQEQ + || op == OPERATOR_NOTEQ + || op == OPERATOR_LT + || op == OPERATOR_LE + || op == OPERATOR_GT + || op == OPERATOR_GE); + + // Numeric constant expressions. + { + Numeric_constant left_nc; + Numeric_constant right_nc; + if (left->numeric_constant_value(&left_nc) + && right->numeric_constant_value(&right_nc)) + { + if (is_comparison) + { + bool result; + if (!Binary_expression::compare_constant(op, &left_nc, + &right_nc, location, + &result)) + return this; + return Expression::make_cast(Type::make_boolean_type(), + Expression::make_boolean(result, + location), + location); + } + else + { + Numeric_constant nc; + if (!Binary_expression::eval_constant(op, &left_nc, &right_nc, + location, &nc)) + return this; + return nc.expression(location); + } + } + } + + // String constant expressions. + if (left->type()->is_string_type() && right->type()->is_string_type()) + { + std::string left_string; + std::string right_string; + if (left->string_constant_value(&left_string) + && right->string_constant_value(&right_string)) + { + if (op == OPERATOR_PLUS) + return Expression::make_string(left_string + right_string, + location); + else if (is_comparison) + { + int cmp = left_string.compare(right_string); + bool r = Binary_expression::cmp_to_bool(op, cmp); + return Expression::make_boolean(r, location); + } + } + } + + // Lower struct, array, and some interface comparisons. + if (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ) + { + if (left->type()->struct_type() != NULL) + return this->lower_struct_comparison(gogo, inserter); + else if (left->type()->array_type() != NULL + && !left->type()->is_slice_type()) + return this->lower_array_comparison(gogo, inserter); + else if ((left->type()->interface_type() != NULL + && right->type()->interface_type() == NULL) + || (left->type()->interface_type() == NULL + && right->type()->interface_type() != NULL)) + return this->lower_interface_value_comparison(gogo, inserter); + } + + return this; +} + +// Lower a struct comparison. + +Expression* +Binary_expression::lower_struct_comparison(Gogo* gogo, + Statement_inserter* inserter) +{ + Struct_type* st = this->left_->type()->struct_type(); + Struct_type* st2 = this->right_->type()->struct_type(); + if (st2 == NULL) + return this; + if (st != st2 && !Type::are_identical(st, st2, false, NULL)) + return this; + if (!Type::are_compatible_for_comparison(true, this->left_->type(), + this->right_->type(), NULL)) + return this; + + // See if we can compare using memcmp. As a heuristic, we use + // memcmp rather than field references and comparisons if there are + // more than two fields. + if (st->compare_is_identity(gogo) && st->total_field_count() > 2) + return this->lower_compare_to_memcmp(gogo, inserter); + + Location loc = this->location(); + + Expression* left = this->left_; + Temporary_statement* left_temp = NULL; + if (left->var_expression() == NULL + && left->temporary_reference_expression() == NULL) + { + left_temp = Statement::make_temporary(left->type(), NULL, loc); + inserter->insert(left_temp); + left = Expression::make_set_and_use_temporary(left_temp, left, loc); + } + + Expression* right = this->right_; + Temporary_statement* right_temp = NULL; + if (right->var_expression() == NULL + && right->temporary_reference_expression() == NULL) + { + right_temp = Statement::make_temporary(right->type(), NULL, loc); + inserter->insert(right_temp); + right = Expression::make_set_and_use_temporary(right_temp, right, loc); + } + + Expression* ret = Expression::make_boolean(true, loc); + const Struct_field_list* fields = st->fields(); + unsigned int field_index = 0; + for (Struct_field_list::const_iterator pf = fields->begin(); + pf != fields->end(); + ++pf, ++field_index) + { + if (Gogo::is_sink_name(pf->field_name())) + continue; + + if (field_index > 0) + { + if (left_temp == NULL) + left = left->copy(); + else + left = Expression::make_temporary_reference(left_temp, loc); + if (right_temp == NULL) + right = right->copy(); + else + right = Expression::make_temporary_reference(right_temp, loc); + } + Expression* f1 = Expression::make_field_reference(left, field_index, + loc); + Expression* f2 = Expression::make_field_reference(right, field_index, + loc); + Expression* cond = Expression::make_binary(OPERATOR_EQEQ, f1, f2, loc); + ret = Expression::make_binary(OPERATOR_ANDAND, ret, cond, loc); + } + + if (this->op_ == OPERATOR_NOTEQ) + ret = Expression::make_unary(OPERATOR_NOT, ret, loc); + + return ret; +} + +// Lower an array comparison. + +Expression* +Binary_expression::lower_array_comparison(Gogo* gogo, + Statement_inserter* inserter) +{ + Array_type* at = this->left_->type()->array_type(); + Array_type* at2 = this->right_->type()->array_type(); + if (at2 == NULL) + return this; + if (at != at2 && !Type::are_identical(at, at2, false, NULL)) + return this; + if (!Type::are_compatible_for_comparison(true, this->left_->type(), + this->right_->type(), NULL)) + return this; + + // Call memcmp directly if possible. This may let the middle-end + // optimize the call. + if (at->compare_is_identity(gogo)) + return this->lower_compare_to_memcmp(gogo, inserter); + + // Call the array comparison function. + Named_object* hash_fn; + Named_object* equal_fn; + at->type_functions(gogo, this->left_->type()->named_type(), NULL, NULL, + &hash_fn, &equal_fn); + + Location loc = this->location(); + + Expression* func = Expression::make_func_reference(equal_fn, NULL, loc); + + Expression_list* args = new Expression_list(); + args->push_back(this->operand_address(inserter, this->left_)); + args->push_back(this->operand_address(inserter, this->right_)); + args->push_back(Expression::make_type_info(at, TYPE_INFO_SIZE)); + + Expression* ret = Expression::make_call(func, args, false, loc); + + if (this->op_ == OPERATOR_NOTEQ) + ret = Expression::make_unary(OPERATOR_NOT, ret, loc); + + return ret; +} + +// Lower an interface to value comparison. + +Expression* +Binary_expression::lower_interface_value_comparison(Gogo*, + Statement_inserter* inserter) +{ + Type* left_type = this->left_->type(); + Type* right_type = this->right_->type(); + Interface_type* ift; + if (left_type->interface_type() != NULL) + { + ift = left_type->interface_type(); + if (!ift->implements_interface(right_type, NULL)) + return this; + } + else + { + ift = right_type->interface_type(); + if (!ift->implements_interface(left_type, NULL)) + return this; + } + if (!Type::are_compatible_for_comparison(true, left_type, right_type, NULL)) + return this; + + Location loc = this->location(); + + if (left_type->interface_type() == NULL + && left_type->points_to() == NULL + && !this->left_->is_addressable()) + { + Temporary_statement* temp = + Statement::make_temporary(left_type, NULL, loc); + inserter->insert(temp); + this->left_ = + Expression::make_set_and_use_temporary(temp, this->left_, loc); + } + + if (right_type->interface_type() == NULL + && right_type->points_to() == NULL + && !this->right_->is_addressable()) + { + Temporary_statement* temp = + Statement::make_temporary(right_type, NULL, loc); + inserter->insert(temp); + this->right_ = + Expression::make_set_and_use_temporary(temp, this->right_, loc); + } + + return this; +} + +// Lower a struct or array comparison to a call to memcmp. + +Expression* +Binary_expression::lower_compare_to_memcmp(Gogo*, Statement_inserter* inserter) +{ + Location loc = this->location(); + + Expression* a1 = this->operand_address(inserter, this->left_); + Expression* a2 = this->operand_address(inserter, this->right_); + Expression* len = Expression::make_type_info(this->left_->type(), + TYPE_INFO_SIZE); + + Expression* call = Runtime::make_call(Runtime::MEMCMP, loc, 3, a1, a2, len); + + mpz_t zval; + mpz_init_set_ui(zval, 0); + Expression* zero = Expression::make_integer(&zval, NULL, loc); + mpz_clear(zval); + + return Expression::make_binary(this->op_, call, zero, loc); +} + +Expression* +Binary_expression::do_flatten(Gogo*, Named_object*, + Statement_inserter* inserter) +{ + Location loc = this->location(); + Temporary_statement* temp; + if (this->left_->type()->is_string_type() + && this->op_ == OPERATOR_PLUS) + { + if (!this->left_->is_variable()) + { + temp = Statement::make_temporary(NULL, this->left_, loc); + inserter->insert(temp); + this->left_ = Expression::make_temporary_reference(temp, loc); + } + if (!this->right_->is_variable()) + { + temp = + Statement::make_temporary(this->left_->type(), this->right_, loc); + this->right_ = Expression::make_temporary_reference(temp, loc); + inserter->insert(temp); + } + } + + Type* left_type = this->left_->type(); + bool is_shift_op = (this->op_ == OPERATOR_LSHIFT + || this->op_ == OPERATOR_RSHIFT); + bool is_idiv_op = ((this->op_ == OPERATOR_DIV && + left_type->integer_type() != NULL) + || this->op_ == OPERATOR_MOD); + + // FIXME: go_check_divide_zero and go_check_divide_overflow are globals + // defined in gcc/go/lang.opt. These should be defined in go_create_gogo + // and accessed from the Gogo* passed to do_flatten. + if (is_shift_op + || (is_idiv_op && (go_check_divide_zero || go_check_divide_overflow))) + { + if (!this->left_->is_variable()) + { + temp = Statement::make_temporary(NULL, this->left_, loc); + inserter->insert(temp); + this->left_ = Expression::make_temporary_reference(temp, loc); + } + if (!this->right_->is_variable()) + { + temp = + Statement::make_temporary(NULL, this->right_, loc); + this->right_ = Expression::make_temporary_reference(temp, loc); + inserter->insert(temp); + } + } + return this; +} + + +// Return the address of EXPR, cast to unsafe.Pointer. + +Expression* +Binary_expression::operand_address(Statement_inserter* inserter, + Expression* expr) +{ + Location loc = this->location(); + + if (!expr->is_addressable()) + { + Temporary_statement* temp = Statement::make_temporary(expr->type(), NULL, + loc); + inserter->insert(temp); + expr = Expression::make_set_and_use_temporary(temp, expr, loc); + } + expr = Expression::make_unary(OPERATOR_AND, expr, loc); + static_cast<Unary_expression*>(expr)->set_does_not_escape(); + Type* void_type = Type::make_void_type(); + Type* unsafe_pointer_type = Type::make_pointer_type(void_type); + return Expression::make_cast(unsafe_pointer_type, expr, loc); +} + +// Return the numeric constant value, if it has one. + +bool +Binary_expression::do_numeric_constant_value(Numeric_constant* nc) const +{ + Numeric_constant left_nc; + if (!this->left_->numeric_constant_value(&left_nc)) + return false; + Numeric_constant right_nc; + if (!this->right_->numeric_constant_value(&right_nc)) + return false; + return Binary_expression::eval_constant(this->op_, &left_nc, &right_nc, + this->location(), nc); +} + +// Note that the value is being discarded. + +bool +Binary_expression::do_discarding_value() +{ + if (this->op_ == OPERATOR_OROR || this->op_ == OPERATOR_ANDAND) + return this->right_->discarding_value(); + else + { + this->unused_value_error(); + return false; + } +} + +// Get type. + +Type* +Binary_expression::do_type() +{ + if (this->classification() == EXPRESSION_ERROR) + return Type::make_error_type(); + + switch (this->op_) + { + case OPERATOR_EQEQ: + case OPERATOR_NOTEQ: + case OPERATOR_LT: + case OPERATOR_LE: + case OPERATOR_GT: + case OPERATOR_GE: + if (this->type_ == NULL) + this->type_ = Type::make_boolean_type(); + return this->type_; + + case OPERATOR_PLUS: + case OPERATOR_MINUS: + case OPERATOR_OR: + case OPERATOR_XOR: + case OPERATOR_MULT: + case OPERATOR_DIV: + case OPERATOR_MOD: + case OPERATOR_AND: + case OPERATOR_BITCLEAR: + case OPERATOR_OROR: + case OPERATOR_ANDAND: + { + Type* type; + if (!Binary_expression::operation_type(this->op_, + this->left_->type(), + this->right_->type(), + &type)) + return Type::make_error_type(); + return type; + } + + case OPERATOR_LSHIFT: + case OPERATOR_RSHIFT: + return this->left_->type(); + + default: + go_unreachable(); + } +} + +// Set type for a binary expression. + +void +Binary_expression::do_determine_type(const Type_context* context) +{ + Type* tleft = this->left_->type(); + Type* tright = this->right_->type(); + + // Both sides should have the same type, except for the shift + // operations. For a comparison, we should ignore the incoming + // type. + + bool is_shift_op = (this->op_ == OPERATOR_LSHIFT + || this->op_ == OPERATOR_RSHIFT); + + bool is_comparison = (this->op_ == OPERATOR_EQEQ + || this->op_ == OPERATOR_NOTEQ + || this->op_ == OPERATOR_LT + || this->op_ == OPERATOR_LE + || this->op_ == OPERATOR_GT + || this->op_ == OPERATOR_GE); + + Type_context subcontext(*context); + + if (is_comparison) + { + // In a comparison, the context does not determine the types of + // the operands. + subcontext.type = NULL; + } + + if (this->op_ == OPERATOR_ANDAND || this->op_ == OPERATOR_OROR) + { + // For a logical operation, the context does not determine the + // types of the operands. The operands must be some boolean + // type but if the context has a boolean type they do not + // inherit it. See http://golang.org/issue/3924. + subcontext.type = NULL; + } + + // Set the context for the left hand operand. + if (is_shift_op) + { + // The right hand operand of a shift plays no role in + // determining the type of the left hand operand. + } + else if (!tleft->is_abstract()) + subcontext.type = tleft; + else if (!tright->is_abstract()) + subcontext.type = tright; + else if (subcontext.type == NULL) + { + if ((tleft->integer_type() != NULL && tright->integer_type() != NULL) + || (tleft->float_type() != NULL && tright->float_type() != NULL) + || (tleft->complex_type() != NULL && tright->complex_type() != NULL)) + { + // Both sides have an abstract integer, abstract float, or + // abstract complex type. Just let CONTEXT determine + // whether they may remain abstract or not. + } + else if (tleft->complex_type() != NULL) + subcontext.type = tleft; + else if (tright->complex_type() != NULL) + subcontext.type = tright; + else if (tleft->float_type() != NULL) + subcontext.type = tleft; + else if (tright->float_type() != NULL) + subcontext.type = tright; + else + subcontext.type = tleft; + + if (subcontext.type != NULL && !context->may_be_abstract) + subcontext.type = subcontext.type->make_non_abstract_type(); + } + + this->left_->determine_type(&subcontext); + + if (is_shift_op) + { + // We may have inherited an unusable type for the shift operand. + // Give a useful error if that happened. + if (tleft->is_abstract() + && subcontext.type != NULL + && !subcontext.may_be_abstract + && subcontext.type->interface_type() == NULL + && subcontext.type->integer_type() == NULL) + this->report_error(("invalid context-determined non-integer type " + "for left operand of shift")); + + // The context for the right hand operand is the same as for the + // left hand operand, except for a shift operator. + subcontext.type = Type::lookup_integer_type("uint"); + subcontext.may_be_abstract = false; + } + + this->right_->determine_type(&subcontext); + + if (is_comparison) + { + if (this->type_ != NULL && !this->type_->is_abstract()) + ; + else if (context->type != NULL && context->type->is_boolean_type()) + this->type_ = context->type; + else if (!context->may_be_abstract) + this->type_ = Type::lookup_bool_type(); + } +} + +// Report an error if the binary operator OP does not support TYPE. +// OTYPE is the type of the other operand. Return whether the +// operation is OK. This should not be used for shift. + +bool +Binary_expression::check_operator_type(Operator op, Type* type, Type* otype, + Location location) +{ + switch (op) + { + case OPERATOR_OROR: + case OPERATOR_ANDAND: + if (!type->is_boolean_type()) + { + error_at(location, "expected boolean type"); + return false; + } + break; + + case OPERATOR_EQEQ: + case OPERATOR_NOTEQ: + { + std::string reason; + if (!Type::are_compatible_for_comparison(true, type, otype, &reason)) + { + error_at(location, "%s", reason.c_str()); + return false; + } + } + break; + + case OPERATOR_LT: + case OPERATOR_LE: + case OPERATOR_GT: + case OPERATOR_GE: + { + std::string reason; + if (!Type::are_compatible_for_comparison(false, type, otype, &reason)) + { + error_at(location, "%s", reason.c_str()); + return false; + } + } + break; + + case OPERATOR_PLUS: + case OPERATOR_PLUSEQ: + if (type->integer_type() == NULL + && type->float_type() == NULL + && type->complex_type() == NULL + && !type->is_string_type()) + { + error_at(location, + "expected integer, floating, complex, or string type"); + return false; + } + break; + + case OPERATOR_MINUS: + case OPERATOR_MINUSEQ: + case OPERATOR_MULT: + case OPERATOR_MULTEQ: + case OPERATOR_DIV: + case OPERATOR_DIVEQ: + if (type->integer_type() == NULL + && type->float_type() == NULL + && type->complex_type() == NULL) + { + error_at(location, "expected integer, floating, or complex type"); + return false; + } + break; + + case OPERATOR_MOD: + case OPERATOR_MODEQ: + case OPERATOR_OR: + case OPERATOR_OREQ: + case OPERATOR_AND: + case OPERATOR_ANDEQ: + case OPERATOR_XOR: + case OPERATOR_XOREQ: + case OPERATOR_BITCLEAR: + case OPERATOR_BITCLEAREQ: + if (type->integer_type() == NULL) + { + error_at(location, "expected integer type"); + return false; + } + break; + + default: + go_unreachable(); + } + + return true; +} + +// Check types. + +void +Binary_expression::do_check_types(Gogo*) +{ + if (this->classification() == EXPRESSION_ERROR) + return; + + Type* left_type = this->left_->type(); + Type* right_type = this->right_->type(); + if (left_type->is_error() || right_type->is_error()) + { + this->set_is_error(); + return; + } + + if (this->op_ == OPERATOR_EQEQ + || this->op_ == OPERATOR_NOTEQ + || this->op_ == OPERATOR_LT + || this->op_ == OPERATOR_LE + || this->op_ == OPERATOR_GT + || this->op_ == OPERATOR_GE) + { + if (left_type->is_nil_type() && right_type->is_nil_type()) + { + this->report_error(_("invalid comparison of nil with nil")); + return; + } + if (!Type::are_assignable(left_type, right_type, NULL) + && !Type::are_assignable(right_type, left_type, NULL)) + { + this->report_error(_("incompatible types in binary expression")); + return; + } + if (!Binary_expression::check_operator_type(this->op_, left_type, + right_type, + this->location()) + || !Binary_expression::check_operator_type(this->op_, right_type, + left_type, + this->location())) + { + this->set_is_error(); + return; + } + } + else if (this->op_ != OPERATOR_LSHIFT && this->op_ != OPERATOR_RSHIFT) + { + if (!Type::are_compatible_for_binop(left_type, right_type)) + { + this->report_error(_("incompatible types in binary expression")); + return; + } + if (!Binary_expression::check_operator_type(this->op_, left_type, + right_type, + this->location())) + { + this->set_is_error(); + return; + } + if (this->op_ == OPERATOR_DIV || this->op_ == OPERATOR_MOD) + { + // Division by a zero integer constant is an error. + Numeric_constant rconst; + unsigned long rval; + if (left_type->integer_type() != NULL + && this->right_->numeric_constant_value(&rconst) + && rconst.to_unsigned_long(&rval) == Numeric_constant::NC_UL_VALID + && rval == 0) + { + this->report_error(_("integer division by zero")); + return; + } + } + } + else + { + if (left_type->integer_type() == NULL) + this->report_error(_("shift of non-integer operand")); + + if (!right_type->is_abstract() + && (right_type->integer_type() == NULL + || !right_type->integer_type()->is_unsigned())) + this->report_error(_("shift count not unsigned integer")); + else + { + Numeric_constant nc; + if (this->right_->numeric_constant_value(&nc)) + { + mpz_t val; + if (!nc.to_int(&val)) + this->report_error(_("shift count not unsigned integer")); + else + { + if (mpz_sgn(val) < 0) + { + this->report_error(_("negative shift count")); + mpz_set_ui(val, 0); + Location rloc = this->right_->location(); + this->right_ = Expression::make_integer(&val, right_type, + rloc); + } + mpz_clear(val); + } + } + } + } +} + +// Get a tree for a binary expression. + +tree +Binary_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Location loc = this->location(); + Type* left_type = this->left_->type(); + Type* right_type = this->right_->type(); + + bool use_left_type = true; + bool is_shift_op = false; + bool is_idiv_op = false; + switch (this->op_) + { + case OPERATOR_EQEQ: + case OPERATOR_NOTEQ: + case OPERATOR_LT: + case OPERATOR_LE: + case OPERATOR_GT: + case OPERATOR_GE: + { + Bexpression* ret = + Expression::comparison(context, this->type_, this->op_, + this->left_, this->right_, loc); + return expr_to_tree(ret); + } + + case OPERATOR_OROR: + case OPERATOR_ANDAND: + use_left_type = false; + break; + case OPERATOR_PLUS: + case OPERATOR_MINUS: + case OPERATOR_OR: + case OPERATOR_XOR: + case OPERATOR_MULT: + break; + case OPERATOR_DIV: + if (left_type->float_type() != NULL || left_type->complex_type() != NULL) + break; + case OPERATOR_MOD: + is_idiv_op = true; + break; + case OPERATOR_LSHIFT: + case OPERATOR_RSHIFT: + is_shift_op = true; + break; + case OPERATOR_BITCLEAR: + this->right_ = Expression::make_unary(OPERATOR_XOR, this->right_, loc); + case OPERATOR_AND: + break; + default: + go_unreachable(); + } + + if (left_type->is_string_type()) + { + go_assert(this->op_ == OPERATOR_PLUS); + Expression* string_plus = + Runtime::make_call(Runtime::STRING_PLUS, loc, 2, + this->left_, this->right_); + return string_plus->get_tree(context); + } + + // For complex division Go might want slightly different results than the + // backend implementation provides, so we have our own runtime routine. + if (this->op_ == OPERATOR_DIV && this->left_->type()->complex_type() != NULL) + { + Runtime::Function complex_code; + switch (this->left_->type()->complex_type()->bits()) + { + case 64: + complex_code = Runtime::COMPLEX64_DIV; + break; + case 128: + complex_code = Runtime::COMPLEX128_DIV; + break; + default: + go_unreachable(); + } + Expression* complex_div = + Runtime::make_call(complex_code, loc, 2, this->left_, this->right_); + return complex_div->get_tree(context); + } + + Bexpression* left = tree_to_expr(this->left_->get_tree(context)); + Bexpression* right = tree_to_expr(this->right_->get_tree(context)); + + Type* type = use_left_type ? left_type : right_type; + Btype* btype = type->get_backend(gogo); + + Bexpression* ret = + gogo->backend()->binary_expression(this->op_, left, right, loc); + ret = gogo->backend()->convert_expression(btype, ret, loc); + + // Initialize overflow constants. + Bexpression* overflow; + mpz_t zero; + mpz_init_set_ui(zero, 0UL); + mpz_t one; + mpz_init_set_ui(one, 1UL); + mpz_t neg_one; + mpz_init_set_si(neg_one, -1); + + Btype* left_btype = left_type->get_backend(gogo); + Btype* right_btype = right_type->get_backend(gogo); + + // In Go, a shift larger than the size of the type is well-defined. + // This is not true in C, so we need to insert a conditional. + if (is_shift_op) + { + go_assert(left_type->integer_type() != NULL); + + mpz_t bitsval; + int bits = left_type->integer_type()->bits(); + mpz_init_set_ui(bitsval, bits); + Bexpression* bits_expr = + gogo->backend()->integer_constant_expression(right_btype, bitsval); + Bexpression* compare = + gogo->backend()->binary_expression(OPERATOR_LT, + right, bits_expr, loc); + + Bexpression* zero_expr = + gogo->backend()->integer_constant_expression(left_btype, zero); + overflow = zero_expr; + if (this->op_ == OPERATOR_RSHIFT + && !left_type->integer_type()->is_unsigned()) + { + Bexpression* neg_expr = + gogo->backend()->binary_expression(OPERATOR_LT, left, + zero_expr, loc); + Bexpression* neg_one_expr = + gogo->backend()->integer_constant_expression(left_btype, neg_one); + overflow = gogo->backend()->conditional_expression(btype, neg_expr, + neg_one_expr, + zero_expr, loc); + } + ret = gogo->backend()->conditional_expression(btype, compare, ret, + overflow, loc); + mpz_clear(bitsval); + } + + // Add checks for division by zero and division overflow as needed. + if (is_idiv_op) + { + if (go_check_divide_zero) + { + // right == 0 + Bexpression* zero_expr = + gogo->backend()->integer_constant_expression(right_btype, zero); + Bexpression* check = + gogo->backend()->binary_expression(OPERATOR_EQEQ, + right, zero_expr, loc); + + // __go_runtime_error(RUNTIME_ERROR_DIVISION_BY_ZERO) + int errcode = RUNTIME_ERROR_DIVISION_BY_ZERO; + Expression* crash = gogo->runtime_error(errcode, loc); + Bexpression* crash_expr = tree_to_expr(crash->get_tree(context)); + + // right == 0 ? (__go_runtime_error(...), 0) : ret + ret = gogo->backend()->conditional_expression(btype, check, + crash_expr, ret, loc); + } + + if (go_check_divide_overflow) + { + // right == -1 + // FIXME: It would be nice to say that this test is expected + // to return false. + + Bexpression* neg_one_expr = + gogo->backend()->integer_constant_expression(right_btype, neg_one); + Bexpression* check = + gogo->backend()->binary_expression(OPERATOR_EQEQ, + right, neg_one_expr, loc); + + Bexpression* zero_expr = + gogo->backend()->integer_constant_expression(btype, zero); + Bexpression* one_expr = + gogo->backend()->integer_constant_expression(btype, one); + + if (type->integer_type()->is_unsigned()) + { + // An unsigned -1 is the largest possible number, so + // dividing is always 1 or 0. + + Bexpression* cmp = + gogo->backend()->binary_expression(OPERATOR_EQEQ, + left, right, loc); + if (this->op_ == OPERATOR_DIV) + overflow = + gogo->backend()->conditional_expression(btype, cmp, + one_expr, zero_expr, + loc); + else + overflow = + gogo->backend()->conditional_expression(btype, cmp, + zero_expr, left, + loc); + } + else + { + // Computing left / -1 is the same as computing - left, + // which does not overflow since Go sets -fwrapv. + if (this->op_ == OPERATOR_DIV) + { + Expression* negate_expr = + Expression::make_unary(OPERATOR_MINUS, this->left_, loc); + overflow = tree_to_expr(negate_expr->get_tree(context)); + } + else + overflow = zero_expr; + } + overflow = gogo->backend()->convert_expression(btype, overflow, loc); + + // right == -1 ? - left : ret + ret = gogo->backend()->conditional_expression(btype, check, overflow, + ret, loc); + } + } + + mpz_clear(zero); + mpz_clear(one); + mpz_clear(neg_one); + return expr_to_tree(ret); +} + +// Export a binary expression. + +void +Binary_expression::do_export(Export* exp) const +{ + exp->write_c_string("("); + this->left_->export_expression(exp); + switch (this->op_) + { + case OPERATOR_OROR: + exp->write_c_string(" || "); + break; + case OPERATOR_ANDAND: + exp->write_c_string(" && "); + break; + case OPERATOR_EQEQ: + exp->write_c_string(" == "); + break; + case OPERATOR_NOTEQ: + exp->write_c_string(" != "); + break; + case OPERATOR_LT: + exp->write_c_string(" < "); + break; + case OPERATOR_LE: + exp->write_c_string(" <= "); + break; + case OPERATOR_GT: + exp->write_c_string(" > "); + break; + case OPERATOR_GE: + exp->write_c_string(" >= "); + break; + case OPERATOR_PLUS: + exp->write_c_string(" + "); + break; + case OPERATOR_MINUS: + exp->write_c_string(" - "); + break; + case OPERATOR_OR: + exp->write_c_string(" | "); + break; + case OPERATOR_XOR: + exp->write_c_string(" ^ "); + break; + case OPERATOR_MULT: + exp->write_c_string(" * "); + break; + case OPERATOR_DIV: + exp->write_c_string(" / "); + break; + case OPERATOR_MOD: + exp->write_c_string(" % "); + break; + case OPERATOR_LSHIFT: + exp->write_c_string(" << "); + break; + case OPERATOR_RSHIFT: + exp->write_c_string(" >> "); + break; + case OPERATOR_AND: + exp->write_c_string(" & "); + break; + case OPERATOR_BITCLEAR: + exp->write_c_string(" &^ "); + break; + default: + go_unreachable(); + } + this->right_->export_expression(exp); + exp->write_c_string(")"); +} + +// Import a binary expression. + +Expression* +Binary_expression::do_import(Import* imp) +{ + imp->require_c_string("("); + + Expression* left = Expression::import_expression(imp); + + Operator op; + if (imp->match_c_string(" || ")) + { + op = OPERATOR_OROR; + imp->advance(4); + } + else if (imp->match_c_string(" && ")) + { + op = OPERATOR_ANDAND; + imp->advance(4); + } + else if (imp->match_c_string(" == ")) + { + op = OPERATOR_EQEQ; + imp->advance(4); + } + else if (imp->match_c_string(" != ")) + { + op = OPERATOR_NOTEQ; + imp->advance(4); + } + else if (imp->match_c_string(" < ")) + { + op = OPERATOR_LT; + imp->advance(3); + } + else if (imp->match_c_string(" <= ")) + { + op = OPERATOR_LE; + imp->advance(4); + } + else if (imp->match_c_string(" > ")) + { + op = OPERATOR_GT; + imp->advance(3); + } + else if (imp->match_c_string(" >= ")) + { + op = OPERATOR_GE; + imp->advance(4); + } + else if (imp->match_c_string(" + ")) + { + op = OPERATOR_PLUS; + imp->advance(3); + } + else if (imp->match_c_string(" - ")) + { + op = OPERATOR_MINUS; + imp->advance(3); + } + else if (imp->match_c_string(" | ")) + { + op = OPERATOR_OR; + imp->advance(3); + } + else if (imp->match_c_string(" ^ ")) + { + op = OPERATOR_XOR; + imp->advance(3); + } + else if (imp->match_c_string(" * ")) + { + op = OPERATOR_MULT; + imp->advance(3); + } + else if (imp->match_c_string(" / ")) + { + op = OPERATOR_DIV; + imp->advance(3); + } + else if (imp->match_c_string(" % ")) + { + op = OPERATOR_MOD; + imp->advance(3); + } + else if (imp->match_c_string(" << ")) + { + op = OPERATOR_LSHIFT; + imp->advance(4); + } + else if (imp->match_c_string(" >> ")) + { + op = OPERATOR_RSHIFT; + imp->advance(4); + } + else if (imp->match_c_string(" & ")) + { + op = OPERATOR_AND; + imp->advance(3); + } + else if (imp->match_c_string(" &^ ")) + { + op = OPERATOR_BITCLEAR; + imp->advance(4); + } + else + { + error_at(imp->location(), "unrecognized binary operator"); + return Expression::make_error(imp->location()); + } + + Expression* right = Expression::import_expression(imp); + + imp->require_c_string(")"); + + return Expression::make_binary(op, left, right, imp->location()); +} + +// Dump ast representation of a binary expression. + +void +Binary_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "("; + ast_dump_context->dump_expression(this->left_); + ast_dump_context->ostream() << " "; + ast_dump_context->dump_operator(this->op_); + ast_dump_context->ostream() << " "; + ast_dump_context->dump_expression(this->right_); + ast_dump_context->ostream() << ") "; +} + +// Make a binary expression. + +Expression* +Expression::make_binary(Operator op, Expression* left, Expression* right, + Location location) +{ + return new Binary_expression(op, left, right, location); +} + +// Implement a comparison. + +Bexpression* +Expression::comparison(Translate_context* context, Type* result_type, + Operator op, Expression* left, Expression* right, + Location location) +{ + Type* left_type = left->type(); + Type* right_type = right->type(); + + mpz_t zval; + mpz_init_set_ui(zval, 0UL); + Expression* zexpr = Expression::make_integer(&zval, NULL, location); + mpz_clear(zval); + + if (left_type->is_string_type() && right_type->is_string_type()) + { + left = Runtime::make_call(Runtime::STRCMP, location, 2, + left, right); + right = zexpr; + } + else if ((left_type->interface_type() != NULL + && right_type->interface_type() == NULL + && !right_type->is_nil_type()) + || (left_type->interface_type() == NULL + && !left_type->is_nil_type() + && right_type->interface_type() != NULL)) + { + // Comparing an interface value to a non-interface value. + if (left_type->interface_type() == NULL) + { + std::swap(left_type, right_type); + std::swap(left, right); + } + + // The right operand is not an interface. We need to take its + // address if it is not a pointer. + Expression* pointer_arg = NULL; + if (right_type->points_to() != NULL) + pointer_arg = right; + else + { + go_assert(right->is_addressable()); + pointer_arg = Expression::make_unary(OPERATOR_AND, right, + location); + } + + Expression* descriptor = + Expression::make_type_descriptor(right_type, location); + left = + Runtime::make_call((left_type->interface_type()->is_empty() + ? Runtime::EMPTY_INTERFACE_VALUE_COMPARE + : Runtime::INTERFACE_VALUE_COMPARE), + location, 3, left, descriptor, + pointer_arg); + right = zexpr; + } + else if (left_type->interface_type() != NULL + && right_type->interface_type() != NULL) + { + Runtime::Function compare_function; + if (left_type->interface_type()->is_empty() + && right_type->interface_type()->is_empty()) + compare_function = Runtime::EMPTY_INTERFACE_COMPARE; + else if (!left_type->interface_type()->is_empty() + && !right_type->interface_type()->is_empty()) + compare_function = Runtime::INTERFACE_COMPARE; + else + { + if (left_type->interface_type()->is_empty()) + { + go_assert(op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ); + std::swap(left_type, right_type); + std::swap(left, right); + } + go_assert(!left_type->interface_type()->is_empty()); + go_assert(right_type->interface_type()->is_empty()); + compare_function = Runtime::INTERFACE_EMPTY_COMPARE; + } + + left = Runtime::make_call(compare_function, location, 2, left, right); + right = zexpr; + } + + if (left_type->is_nil_type() + && (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ)) + { + std::swap(left_type, right_type); + std::swap(left, right); + } + + if (right_type->is_nil_type()) + { + right = Expression::make_nil(location); + if (left_type->array_type() != NULL + && left_type->array_type()->length() == NULL) + { + Array_type* at = left_type->array_type(); + left = at->get_value_pointer(context->gogo(), left); + } + else if (left_type->interface_type() != NULL) + { + // An interface is nil if the first field is nil. + left = Expression::make_field_reference(left, 0, location); + } + } + + Bexpression* left_bexpr = tree_to_expr(left->get_tree(context)); + Bexpression* right_bexpr = tree_to_expr(right->get_tree(context)); + + Gogo* gogo = context->gogo(); + Bexpression* ret = gogo->backend()->binary_expression(op, left_bexpr, + right_bexpr, location); + if (result_type != NULL) + ret = gogo->backend()->convert_expression(result_type->get_backend(gogo), + ret, location); + return ret; +} + +// Class Bound_method_expression. + +// Traversal. + +int +Bound_method_expression::do_traverse(Traverse* traverse) +{ + return Expression::traverse(&this->expr_, traverse); +} + +// Lower the expression. If this is a method value rather than being +// called, and the method is accessed via a pointer, we may need to +// add nil checks. Introduce a temporary variable so that those nil +// checks do not cause multiple evaluation. + +Expression* +Bound_method_expression::do_lower(Gogo*, Named_object*, + Statement_inserter* inserter, int) +{ + // For simplicity we use a temporary for every call to an embedded + // method, even though some of them might be pure value methods and + // not require a temporary. + if (this->expr_->var_expression() == NULL + && this->expr_->temporary_reference_expression() == NULL + && this->expr_->set_and_use_temporary_expression() == NULL + && (this->method_->field_indexes() != NULL + || (this->method_->is_value_method() + && this->expr_->type()->points_to() != NULL))) + { + Temporary_statement* temp = + Statement::make_temporary(this->expr_->type(), NULL, this->location()); + inserter->insert(temp); + this->expr_ = Expression::make_set_and_use_temporary(temp, this->expr_, + this->location()); + } + return this; +} + +// Return the type of a bound method expression. The type of this +// object is simply the type of the method with no receiver. + +Type* +Bound_method_expression::do_type() +{ + Named_object* fn = this->method_->named_object(); + Function_type* fntype; + if (fn->is_function()) + fntype = fn->func_value()->type(); + else if (fn->is_function_declaration()) + fntype = fn->func_declaration_value()->type(); + else + return Type::make_error_type(); + return fntype->copy_without_receiver(); +} + +// Determine the types of a method expression. + +void +Bound_method_expression::do_determine_type(const Type_context*) +{ + Named_object* fn = this->method_->named_object(); + Function_type* fntype; + if (fn->is_function()) + fntype = fn->func_value()->type(); + else if (fn->is_function_declaration()) + fntype = fn->func_declaration_value()->type(); + else + fntype = NULL; + if (fntype == NULL || !fntype->is_method()) + this->expr_->determine_type_no_context(); + else + { + Type_context subcontext(fntype->receiver()->type(), false); + this->expr_->determine_type(&subcontext); + } +} + +// Check the types of a method expression. + +void +Bound_method_expression::do_check_types(Gogo*) +{ + Named_object* fn = this->method_->named_object(); + if (!fn->is_function() && !fn->is_function_declaration()) + { + this->report_error(_("object is not a method")); + return; + } + + Function_type* fntype; + if (fn->is_function()) + fntype = fn->func_value()->type(); + else if (fn->is_function_declaration()) + fntype = fn->func_declaration_value()->type(); + else + go_unreachable(); + Type* rtype = fntype->receiver()->type()->deref(); + Type* etype = (this->expr_type_ != NULL + ? this->expr_type_ + : this->expr_->type()); + etype = etype->deref(); + if (!Type::are_identical(rtype, etype, true, NULL)) + this->report_error(_("method type does not match object type")); +} + +// If a bound method expression is not simply called, then it is +// represented as a closure. The closure will hold a single variable, +// the receiver to pass to the method. The function will be a simple +// thunk that pulls that value from the closure and calls the method +// with the remaining arguments. +// +// Because method values are not common, we don't build all thunks for +// every methods, but instead only build them as we need them. In +// particular, we even build them on demand for methods defined in +// other packages. + +Bound_method_expression::Method_value_thunks + Bound_method_expression::method_value_thunks; + +// Find or create the thunk for METHOD. + +Named_object* +Bound_method_expression::create_thunk(Gogo* gogo, const Method* method, + Named_object* fn) +{ + std::pair<Named_object*, Named_object*> val(fn, NULL); + std::pair<Method_value_thunks::iterator, bool> ins = + Bound_method_expression::method_value_thunks.insert(val); + if (!ins.second) + { + // We have seen this method before. + go_assert(ins.first->second != NULL); + return ins.first->second; + } + + Location loc = fn->location(); + + Function_type* orig_fntype; + if (fn->is_function()) + orig_fntype = fn->func_value()->type(); + else if (fn->is_function_declaration()) + orig_fntype = fn->func_declaration_value()->type(); + else + orig_fntype = NULL; + + if (orig_fntype == NULL || !orig_fntype->is_method()) + { + ins.first->second = Named_object::make_erroneous_name(Gogo::thunk_name()); + return ins.first->second; + } + + Struct_field_list* sfl = new Struct_field_list(); + // The type here is wrong--it should be the C function type. But it + // doesn't really matter. + Type* vt = Type::make_pointer_type(Type::make_void_type()); + sfl->push_back(Struct_field(Typed_identifier("fn.0", vt, loc))); + sfl->push_back(Struct_field(Typed_identifier("val.1", + orig_fntype->receiver()->type(), + loc))); + Type* closure_type = Type::make_struct_type(sfl, loc); + closure_type = Type::make_pointer_type(closure_type); + + Function_type* new_fntype = orig_fntype->copy_with_names(); + + Named_object* new_no = gogo->start_function(Gogo::thunk_name(), new_fntype, + false, loc); + + Variable* cvar = new Variable(closure_type, NULL, false, false, false, loc); + cvar->set_is_used(); + Named_object* cp = Named_object::make_variable("$closure", NULL, cvar); + new_no->func_value()->set_closure_var(cp); + + gogo->start_block(loc); + + // Field 0 of the closure is the function code pointer, field 1 is + // the value on which to invoke the method. + Expression* arg = Expression::make_var_reference(cp, loc); + arg = Expression::make_unary(OPERATOR_MULT, arg, loc); + arg = Expression::make_field_reference(arg, 1, loc); + + Expression* bme = Expression::make_bound_method(arg, method, fn, loc); + + const Typed_identifier_list* orig_params = orig_fntype->parameters(); + Expression_list* args; + if (orig_params == NULL || orig_params->empty()) + args = NULL; + else + { + const Typed_identifier_list* new_params = new_fntype->parameters(); + args = new Expression_list(); + for (Typed_identifier_list::const_iterator p = new_params->begin(); + p != new_params->end(); + ++p) + { + Named_object* p_no = gogo->lookup(p->name(), NULL); + go_assert(p_no != NULL + && p_no->is_variable() + && p_no->var_value()->is_parameter()); + args->push_back(Expression::make_var_reference(p_no, loc)); + } + } + + Call_expression* call = Expression::make_call(bme, args, + orig_fntype->is_varargs(), + loc); + call->set_varargs_are_lowered(); + + Statement* s = Statement::make_return_from_call(call, loc); + gogo->add_statement(s); + Block* b = gogo->finish_block(loc); + gogo->add_block(b, loc); + gogo->lower_block(new_no, b); + gogo->flatten_block(new_no, b); + gogo->finish_function(loc); + + ins.first->second = new_no; + return new_no; +} + +// Return an expression to check *REF for nil while dereferencing +// according to FIELD_INDEXES. Update *REF to build up the field +// reference. This is a static function so that we don't have to +// worry about declaring Field_indexes in expressions.h. + +static Expression* +bme_check_nil(const Method::Field_indexes* field_indexes, Location loc, + Expression** ref) +{ + if (field_indexes == NULL) + return Expression::make_boolean(false, loc); + Expression* cond = bme_check_nil(field_indexes->next, loc, ref); + Struct_type* stype = (*ref)->type()->deref()->struct_type(); + go_assert(stype != NULL + && field_indexes->field_index < stype->field_count()); + if ((*ref)->type()->struct_type() == NULL) + { + go_assert((*ref)->type()->points_to() != NULL); + Expression* n = Expression::make_binary(OPERATOR_EQEQ, *ref, + Expression::make_nil(loc), + loc); + cond = Expression::make_binary(OPERATOR_OROR, cond, n, loc); + *ref = Expression::make_unary(OPERATOR_MULT, *ref, loc); + go_assert((*ref)->type()->struct_type() == stype); + } + *ref = Expression::make_field_reference(*ref, field_indexes->field_index, + loc); + return cond; +} + +// Get the tree for a method value. + +tree +Bound_method_expression::do_get_tree(Translate_context* context) +{ + Named_object* thunk = Bound_method_expression::create_thunk(context->gogo(), + this->method_, + this->function_); + if (thunk->is_erroneous()) + { + go_assert(saw_errors()); + return error_mark_node; + } + + // FIXME: We should lower this earlier, but we can't lower it in the + // lowering pass because at that point we don't know whether we need + // to create the thunk or not. If the expression is called, we + // don't need the thunk. + + Location loc = this->location(); + + // If the method expects a value, and we have a pointer, we need to + // dereference the pointer. + + Named_object* fn = this->method_->named_object(); + Function_type* fntype; + if (fn->is_function()) + fntype = fn->func_value()->type(); + else if (fn->is_function_declaration()) + fntype = fn->func_declaration_value()->type(); + else + go_unreachable(); + + Expression* val = this->expr_; + if (fntype->receiver()->type()->points_to() == NULL + && val->type()->points_to() != NULL) + val = Expression::make_unary(OPERATOR_MULT, val, loc); + + // Note that we are ignoring this->expr_type_ here. The thunk will + // expect a closure whose second field has type this->expr_type_ (if + // that is not NULL). We are going to pass it a closure whose + // second field has type this->expr_->type(). Since + // this->expr_type_ is only not-NULL for pointer types, we can get + // away with this. + + Struct_field_list* fields = new Struct_field_list(); + fields->push_back(Struct_field(Typed_identifier("fn.0", + thunk->func_value()->type(), + loc))); + fields->push_back(Struct_field(Typed_identifier("val.1", val->type(), loc))); + Struct_type* st = Type::make_struct_type(fields, loc); + + Expression_list* vals = new Expression_list(); + vals->push_back(Expression::make_func_code_reference(thunk, loc)); + vals->push_back(val); + + Expression* ret = Expression::make_struct_composite_literal(st, vals, loc); + ret = Expression::make_heap_composite(ret, loc); + + tree ret_tree = ret->get_tree(context); + + Expression* nil_check = NULL; + + // See whether the expression or any embedded pointers are nil. + + Expression* expr = this->expr_; + if (this->method_->field_indexes() != NULL) + { + // Note that we are evaluating this->expr_ twice, but that is OK + // because in the lowering pass we forced it into a temporary + // variable. + Expression* ref = expr; + nil_check = bme_check_nil(this->method_->field_indexes(), loc, &ref); + expr = ref; + } + + if (this->method_->is_value_method() && expr->type()->points_to() != NULL) + { + Expression* n = Expression::make_binary(OPERATOR_EQEQ, expr, + Expression::make_nil(loc), + loc); + if (nil_check == NULL) + nil_check = n; + else + nil_check = Expression::make_binary(OPERATOR_OROR, nil_check, n, loc); + } + + if (nil_check != NULL) + { + tree nil_check_tree = nil_check->get_tree(context); + Expression* crash_expr = + context->gogo()->runtime_error(RUNTIME_ERROR_NIL_DEREFERENCE, loc); + tree crash = crash_expr->get_tree(context); + if (ret_tree == error_mark_node + || nil_check_tree == error_mark_node + || crash == error_mark_node) + return error_mark_node; + + ret_tree = fold_build2_loc(loc.gcc_location(), COMPOUND_EXPR, + TREE_TYPE(ret_tree), + build3_loc(loc.gcc_location(), COND_EXPR, + void_type_node, nil_check_tree, + crash, NULL_TREE), + ret_tree); + } + + return ret_tree; +} + +// Dump ast representation of a bound method expression. + +void +Bound_method_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + if (this->expr_type_ != NULL) + ast_dump_context->ostream() << "("; + ast_dump_context->dump_expression(this->expr_); + if (this->expr_type_ != NULL) + { + ast_dump_context->ostream() << ":"; + ast_dump_context->dump_type(this->expr_type_); + ast_dump_context->ostream() << ")"; + } + + ast_dump_context->ostream() << "." << this->function_->name(); +} + +// Make a method expression. + +Bound_method_expression* +Expression::make_bound_method(Expression* expr, const Method* method, + Named_object* function, Location location) +{ + return new Bound_method_expression(expr, method, function, location); +} + +// Class Builtin_call_expression. This is used for a call to a +// builtin function. + +class Builtin_call_expression : public Call_expression +{ + public: + Builtin_call_expression(Gogo* gogo, Expression* fn, Expression_list* args, + bool is_varargs, Location location); + + protected: + // This overrides Call_expression::do_lower. + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int); + + Expression* + do_flatten(Gogo*, Named_object*, Statement_inserter*); + + bool + do_is_constant() const; + + bool + do_numeric_constant_value(Numeric_constant*) const; + + bool + do_discarding_value(); + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return new Builtin_call_expression(this->gogo_, this->fn()->copy(), + this->args()->copy(), + this->is_varargs(), + this->location()); + } + + tree + do_get_tree(Translate_context*); + + void + do_export(Export*) const; + + virtual bool + do_is_recover_call() const; + + virtual void + do_set_recover_arg(Expression*); + + private: + // The builtin functions. + enum Builtin_function_code + { + BUILTIN_INVALID, + + // Predeclared builtin functions. + BUILTIN_APPEND, + BUILTIN_CAP, + BUILTIN_CLOSE, + BUILTIN_COMPLEX, + BUILTIN_COPY, + BUILTIN_DELETE, + BUILTIN_IMAG, + BUILTIN_LEN, + BUILTIN_MAKE, + BUILTIN_NEW, + BUILTIN_PANIC, + BUILTIN_PRINT, + BUILTIN_PRINTLN, + BUILTIN_REAL, + BUILTIN_RECOVER, + + // Builtin functions from the unsafe package. + BUILTIN_ALIGNOF, + BUILTIN_OFFSETOF, + BUILTIN_SIZEOF + }; + + Expression* + one_arg() const; + + bool + check_one_arg(); + + static Type* + real_imag_type(Type*); + + static Type* + complex_type(Type*); + + Expression* + lower_make(); + + bool + check_int_value(Expression*, bool is_length); + + // A pointer back to the general IR structure. This avoids a global + // variable, or passing it around everywhere. + Gogo* gogo_; + // The builtin function being called. + Builtin_function_code code_; + // Used to stop endless loops when the length of an array uses len + // or cap of the array itself. + mutable bool seen_; +}; + +Builtin_call_expression::Builtin_call_expression(Gogo* gogo, + Expression* fn, + Expression_list* args, + bool is_varargs, + Location location) + : Call_expression(fn, args, is_varargs, location), + gogo_(gogo), code_(BUILTIN_INVALID), seen_(false) +{ + Func_expression* fnexp = this->fn()->func_expression(); + go_assert(fnexp != NULL); + const std::string& name(fnexp->named_object()->name()); + if (name == "append") + this->code_ = BUILTIN_APPEND; + else if (name == "cap") + this->code_ = BUILTIN_CAP; + else if (name == "close") + this->code_ = BUILTIN_CLOSE; + else if (name == "complex") + this->code_ = BUILTIN_COMPLEX; + else if (name == "copy") + this->code_ = BUILTIN_COPY; + else if (name == "delete") + this->code_ = BUILTIN_DELETE; + else if (name == "imag") + this->code_ = BUILTIN_IMAG; + else if (name == "len") + this->code_ = BUILTIN_LEN; + else if (name == "make") + this->code_ = BUILTIN_MAKE; + else if (name == "new") + this->code_ = BUILTIN_NEW; + else if (name == "panic") + this->code_ = BUILTIN_PANIC; + else if (name == "print") + this->code_ = BUILTIN_PRINT; + else if (name == "println") + this->code_ = BUILTIN_PRINTLN; + else if (name == "real") + this->code_ = BUILTIN_REAL; + else if (name == "recover") + this->code_ = BUILTIN_RECOVER; + else if (name == "Alignof") + this->code_ = BUILTIN_ALIGNOF; + else if (name == "Offsetof") + this->code_ = BUILTIN_OFFSETOF; + else if (name == "Sizeof") + this->code_ = BUILTIN_SIZEOF; + else + go_unreachable(); +} + +// Return whether this is a call to recover. This is a virtual +// function called from the parent class. + +bool +Builtin_call_expression::do_is_recover_call() const +{ + if (this->classification() == EXPRESSION_ERROR) + return false; + return this->code_ == BUILTIN_RECOVER; +} + +// Set the argument for a call to recover. + +void +Builtin_call_expression::do_set_recover_arg(Expression* arg) +{ + const Expression_list* args = this->args(); + go_assert(args == NULL || args->empty()); + Expression_list* new_args = new Expression_list(); + new_args->push_back(arg); + this->set_args(new_args); +} + +// Lower a builtin call expression. This turns new and make into +// specific expressions. We also convert to a constant if we can. + +Expression* +Builtin_call_expression::do_lower(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, int) +{ + if (this->classification() == EXPRESSION_ERROR) + return this; + + Location loc = this->location(); + + if (this->is_varargs() && this->code_ != BUILTIN_APPEND) + { + this->report_error(_("invalid use of %<...%> with builtin function")); + return Expression::make_error(loc); + } + + if (this->code_ == BUILTIN_OFFSETOF) + { + Expression* arg = this->one_arg(); + + if (arg->bound_method_expression() != NULL + || arg->interface_field_reference_expression() != NULL) + { + this->report_error(_("invalid use of method value as argument " + "of Offsetof")); + return this; + } + + Field_reference_expression* farg = arg->field_reference_expression(); + while (farg != NULL) + { + if (!farg->implicit()) + break; + // When the selector refers to an embedded field, + // it must not be reached through pointer indirections. + if (farg->expr()->deref() != farg->expr()) + { + this->report_error(_("argument of Offsetof implies " + "indirection of an embedded field")); + return this; + } + // Go up until we reach the original base. + farg = farg->expr()->field_reference_expression(); + } + } + + if (this->is_constant()) + { + Numeric_constant nc; + if (this->numeric_constant_value(&nc)) + return nc.expression(loc); + } + + switch (this->code_) + { + default: + break; + + case BUILTIN_NEW: + { + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 1) + this->report_error(_("not enough arguments")); + else if (args->size() > 1) + this->report_error(_("too many arguments")); + else + { + Expression* arg = args->front(); + if (!arg->is_type_expression()) + { + error_at(arg->location(), "expected type"); + this->set_is_error(); + } + else + return Expression::make_allocation(arg->type(), loc); + } + } + break; + + case BUILTIN_MAKE: + return this->lower_make(); + + case BUILTIN_RECOVER: + if (function != NULL) + function->func_value()->set_calls_recover(); + else + { + // Calling recover outside of a function always returns the + // nil empty interface. + Type* eface = Type::make_empty_interface_type(loc); + return Expression::make_cast(eface, Expression::make_nil(loc), loc); + } + break; + + case BUILTIN_APPEND: + { + // Lower the varargs. + const Expression_list* args = this->args(); + if (args == NULL || args->empty()) + return this; + Type* slice_type = args->front()->type(); + if (!slice_type->is_slice_type()) + { + if (slice_type->is_nil_type()) + error_at(args->front()->location(), "use of untyped nil"); + else + error_at(args->front()->location(), + "argument 1 must be a slice"); + this->set_is_error(); + return this; + } + Type* element_type = slice_type->array_type()->element_type(); + this->lower_varargs(gogo, function, inserter, + Type::make_array_type(element_type, NULL), + 2); + } + break; + + case BUILTIN_DELETE: + { + // Lower to a runtime function call. + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 2) + this->report_error(_("not enough arguments")); + else if (args->size() > 2) + this->report_error(_("too many arguments")); + else if (args->front()->type()->map_type() == NULL) + this->report_error(_("argument 1 must be a map")); + else + { + // Since this function returns no value it must appear in + // a statement by itself, so we don't have to worry about + // order of evaluation of values around it. Evaluate the + // map first to get order of evaluation right. + Map_type* mt = args->front()->type()->map_type(); + Temporary_statement* map_temp = + Statement::make_temporary(mt, args->front(), loc); + inserter->insert(map_temp); + + Temporary_statement* key_temp = + Statement::make_temporary(mt->key_type(), args->back(), loc); + inserter->insert(key_temp); + + Expression* e1 = Expression::make_temporary_reference(map_temp, + loc); + Expression* e2 = Expression::make_temporary_reference(key_temp, + loc); + e2 = Expression::make_unary(OPERATOR_AND, e2, loc); + return Runtime::make_call(Runtime::MAPDELETE, this->location(), + 2, e1, e2); + } + } + break; + } + + return this; +} + +// Flatten a builtin call expression. This turns the arguments of copy and +// append into temporary expressions. + +Expression* +Builtin_call_expression::do_flatten(Gogo*, Named_object*, + Statement_inserter* inserter) +{ + if (this->code_ == BUILTIN_APPEND + || this->code_ == BUILTIN_COPY) + { + Location loc = this->location(); + Type* at = this->args()->front()->type(); + for (Expression_list::iterator pa = this->args()->begin(); + pa != this->args()->end(); + ++pa) + { + if ((*pa)->is_nil_expression()) + *pa = Expression::make_slice_composite_literal(at, NULL, loc); + if (!(*pa)->is_variable()) + { + Temporary_statement* temp = + Statement::make_temporary(NULL, *pa, loc); + inserter->insert(temp); + *pa = Expression::make_temporary_reference(temp, loc); + } + } + } + return this; +} + +// Lower a make expression. + +Expression* +Builtin_call_expression::lower_make() +{ + Location loc = this->location(); + + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 1) + { + this->report_error(_("not enough arguments")); + return Expression::make_error(this->location()); + } + + Expression_list::const_iterator parg = args->begin(); + + Expression* first_arg = *parg; + if (!first_arg->is_type_expression()) + { + error_at(first_arg->location(), "expected type"); + this->set_is_error(); + return Expression::make_error(this->location()); + } + Type* type = first_arg->type(); + + bool is_slice = false; + bool is_map = false; + bool is_chan = false; + if (type->is_slice_type()) + is_slice = true; + else if (type->map_type() != NULL) + is_map = true; + else if (type->channel_type() != NULL) + is_chan = true; + else + { + this->report_error(_("invalid type for make function")); + return Expression::make_error(this->location()); + } + + bool have_big_args = false; + Type* uintptr_type = Type::lookup_integer_type("uintptr"); + int uintptr_bits = uintptr_type->integer_type()->bits(); + + Type_context int_context(Type::lookup_integer_type("int"), false); + + ++parg; + Expression* len_arg; + if (parg == args->end()) + { + if (is_slice) + { + this->report_error(_("length required when allocating a slice")); + return Expression::make_error(this->location()); + } + + mpz_t zval; + mpz_init_set_ui(zval, 0); + len_arg = Expression::make_integer(&zval, NULL, loc); + mpz_clear(zval); + } + else + { + len_arg = *parg; + len_arg->determine_type(&int_context); + if (!this->check_int_value(len_arg, true)) + return Expression::make_error(this->location()); + if (len_arg->type()->integer_type() != NULL + && len_arg->type()->integer_type()->bits() > uintptr_bits) + have_big_args = true; + ++parg; + } + + Expression* cap_arg = NULL; + if (is_slice && parg != args->end()) + { + cap_arg = *parg; + cap_arg->determine_type(&int_context); + if (!this->check_int_value(cap_arg, false)) + return Expression::make_error(this->location()); + + Numeric_constant nclen; + Numeric_constant nccap; + unsigned long vlen; + unsigned long vcap; + if (len_arg->numeric_constant_value(&nclen) + && cap_arg->numeric_constant_value(&nccap) + && nclen.to_unsigned_long(&vlen) == Numeric_constant::NC_UL_VALID + && nccap.to_unsigned_long(&vcap) == Numeric_constant::NC_UL_VALID + && vlen > vcap) + { + this->report_error(_("len larger than cap")); + return Expression::make_error(this->location()); + } + + if (cap_arg->type()->integer_type() != NULL + && cap_arg->type()->integer_type()->bits() > uintptr_bits) + have_big_args = true; + ++parg; + } + + if (parg != args->end()) + { + this->report_error(_("too many arguments to make")); + return Expression::make_error(this->location()); + } + + Location type_loc = first_arg->location(); + Expression* type_arg; + if (is_slice || is_chan) + type_arg = Expression::make_type_descriptor(type, type_loc); + else if (is_map) + type_arg = Expression::make_map_descriptor(type->map_type(), type_loc); + else + go_unreachable(); + + Expression* call; + if (is_slice) + { + if (cap_arg == NULL) + call = Runtime::make_call((have_big_args + ? Runtime::MAKESLICE1BIG + : Runtime::MAKESLICE1), + loc, 2, type_arg, len_arg); + else + call = Runtime::make_call((have_big_args + ? Runtime::MAKESLICE2BIG + : Runtime::MAKESLICE2), + loc, 3, type_arg, len_arg, cap_arg); + } + else if (is_map) + call = Runtime::make_call((have_big_args + ? Runtime::MAKEMAPBIG + : Runtime::MAKEMAP), + loc, 2, type_arg, len_arg); + else if (is_chan) + call = Runtime::make_call((have_big_args + ? Runtime::MAKECHANBIG + : Runtime::MAKECHAN), + loc, 2, type_arg, len_arg); + else + go_unreachable(); + + return Expression::make_unsafe_cast(type, call, loc); +} + +// Return whether an expression has an integer value. Report an error +// if not. This is used when handling calls to the predeclared make +// function. + +bool +Builtin_call_expression::check_int_value(Expression* e, bool is_length) +{ + Numeric_constant nc; + if (e->numeric_constant_value(&nc)) + { + unsigned long v; + switch (nc.to_unsigned_long(&v)) + { + case Numeric_constant::NC_UL_VALID: + break; + case Numeric_constant::NC_UL_NOTINT: + error_at(e->location(), "non-integer %s argument to make", + is_length ? "len" : "cap"); + return false; + case Numeric_constant::NC_UL_NEGATIVE: + error_at(e->location(), "negative %s argument to make", + is_length ? "len" : "cap"); + return false; + case Numeric_constant::NC_UL_BIG: + // We don't want to give a compile-time error for a 64-bit + // value on a 32-bit target. + break; + } + + mpz_t val; + if (!nc.to_int(&val)) + go_unreachable(); + int bits = mpz_sizeinbase(val, 2); + mpz_clear(val); + Type* int_type = Type::lookup_integer_type("int"); + if (bits >= int_type->integer_type()->bits()) + { + error_at(e->location(), "%s argument too large for make", + is_length ? "len" : "cap"); + return false; + } + + return true; + } + + if (e->type()->integer_type() != NULL) + return true; + + error_at(e->location(), "non-integer %s argument to make", + is_length ? "len" : "cap"); + return false; +} + +// Return the type of the real or imag functions, given the type of +// the argument. We need to map complex to float, complex64 to +// float32, and complex128 to float64, so it has to be done by name. +// This returns NULL if it can't figure out the type. + +Type* +Builtin_call_expression::real_imag_type(Type* arg_type) +{ + if (arg_type == NULL || arg_type->is_abstract()) + return NULL; + Named_type* nt = arg_type->named_type(); + if (nt == NULL) + return NULL; + while (nt->real_type()->named_type() != NULL) + nt = nt->real_type()->named_type(); + if (nt->name() == "complex64") + return Type::lookup_float_type("float32"); + else if (nt->name() == "complex128") + return Type::lookup_float_type("float64"); + else + return NULL; +} + +// Return the type of the complex function, given the type of one of the +// argments. Like real_imag_type, we have to map by name. + +Type* +Builtin_call_expression::complex_type(Type* arg_type) +{ + if (arg_type == NULL || arg_type->is_abstract()) + return NULL; + Named_type* nt = arg_type->named_type(); + if (nt == NULL) + return NULL; + while (nt->real_type()->named_type() != NULL) + nt = nt->real_type()->named_type(); + if (nt->name() == "float32") + return Type::lookup_complex_type("complex64"); + else if (nt->name() == "float64") + return Type::lookup_complex_type("complex128"); + else + return NULL; +} + +// Return a single argument, or NULL if there isn't one. + +Expression* +Builtin_call_expression::one_arg() const +{ + const Expression_list* args = this->args(); + if (args == NULL || args->size() != 1) + return NULL; + return args->front(); +} + +// A traversal class which looks for a call or receive expression. + +class Find_call_expression : public Traverse +{ + public: + Find_call_expression() + : Traverse(traverse_expressions), + found_(false) + { } + + int + expression(Expression**); + + bool + found() + { return this->found_; } + + private: + bool found_; +}; + +int +Find_call_expression::expression(Expression** pexpr) +{ + if ((*pexpr)->call_expression() != NULL + || (*pexpr)->receive_expression() != NULL) + { + this->found_ = true; + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Return whether this is constant: len of a string constant, or len +// or cap of an array, or unsafe.Sizeof, unsafe.Offsetof, +// unsafe.Alignof. + +bool +Builtin_call_expression::do_is_constant() const +{ + if (this->is_error_expression()) + return true; + switch (this->code_) + { + case BUILTIN_LEN: + case BUILTIN_CAP: + { + if (this->seen_) + return false; + + Expression* arg = this->one_arg(); + if (arg == NULL) + return false; + Type* arg_type = arg->type(); + + if (arg_type->points_to() != NULL + && arg_type->points_to()->array_type() != NULL + && !arg_type->points_to()->is_slice_type()) + arg_type = arg_type->points_to(); + + // The len and cap functions are only constant if there are no + // function calls or channel operations in the arguments. + // Otherwise we have to make the call. + if (!arg->is_constant()) + { + Find_call_expression find_call; + Expression::traverse(&arg, &find_call); + if (find_call.found()) + return false; + } + + if (arg_type->array_type() != NULL + && arg_type->array_type()->length() != NULL) + return true; + + if (this->code_ == BUILTIN_LEN && arg_type->is_string_type()) + { + this->seen_ = true; + bool ret = arg->is_constant(); + this->seen_ = false; + return ret; + } + } + break; + + case BUILTIN_SIZEOF: + case BUILTIN_ALIGNOF: + return this->one_arg() != NULL; + + case BUILTIN_OFFSETOF: + { + Expression* arg = this->one_arg(); + if (arg == NULL) + return false; + return arg->field_reference_expression() != NULL; + } + + case BUILTIN_COMPLEX: + { + const Expression_list* args = this->args(); + if (args != NULL && args->size() == 2) + return args->front()->is_constant() && args->back()->is_constant(); + } + break; + + case BUILTIN_REAL: + case BUILTIN_IMAG: + { + Expression* arg = this->one_arg(); + return arg != NULL && arg->is_constant(); + } + + default: + break; + } + + return false; +} + +// Return a numeric constant if possible. + +bool +Builtin_call_expression::do_numeric_constant_value(Numeric_constant* nc) const +{ + if (this->code_ == BUILTIN_LEN + || this->code_ == BUILTIN_CAP) + { + Expression* arg = this->one_arg(); + if (arg == NULL) + return false; + Type* arg_type = arg->type(); + + if (this->code_ == BUILTIN_LEN && arg_type->is_string_type()) + { + std::string sval; + if (arg->string_constant_value(&sval)) + { + nc->set_unsigned_long(Type::lookup_integer_type("int"), + sval.length()); + return true; + } + } + + if (arg_type->points_to() != NULL + && arg_type->points_to()->array_type() != NULL + && !arg_type->points_to()->is_slice_type()) + arg_type = arg_type->points_to(); + + if (arg_type->array_type() != NULL + && arg_type->array_type()->length() != NULL) + { + if (this->seen_) + return false; + Expression* e = arg_type->array_type()->length(); + this->seen_ = true; + bool r = e->numeric_constant_value(nc); + this->seen_ = false; + if (r) + { + if (!nc->set_type(Type::lookup_integer_type("int"), false, + this->location())) + r = false; + } + return r; + } + } + else if (this->code_ == BUILTIN_SIZEOF + || this->code_ == BUILTIN_ALIGNOF) + { + Expression* arg = this->one_arg(); + if (arg == NULL) + return false; + Type* arg_type = arg->type(); + if (arg_type->is_error()) + return false; + if (arg_type->is_abstract()) + return false; + + unsigned int ret; + if (this->code_ == BUILTIN_SIZEOF) + { + if (!arg_type->backend_type_size(this->gogo_, &ret)) + return false; + } + else if (this->code_ == BUILTIN_ALIGNOF) + { + if (arg->field_reference_expression() == NULL) + { + if (!arg_type->backend_type_align(this->gogo_, &ret)) + return false; + } + else + { + // Calling unsafe.Alignof(s.f) returns the alignment of + // the type of f when it is used as a field in a struct. + if (!arg_type->backend_type_field_align(this->gogo_, &ret)) + return false; + } + } + else + go_unreachable(); + + nc->set_unsigned_long(Type::lookup_integer_type("uintptr"), + static_cast<unsigned long>(ret)); + return true; + } + else if (this->code_ == BUILTIN_OFFSETOF) + { + Expression* arg = this->one_arg(); + if (arg == NULL) + return false; + Field_reference_expression* farg = arg->field_reference_expression(); + if (farg == NULL) + return false; + unsigned int total_offset = 0; + while (true) + { + Expression* struct_expr = farg->expr(); + Type* st = struct_expr->type(); + if (st->struct_type() == NULL) + return false; + if (st->named_type() != NULL) + st->named_type()->convert(this->gogo_); + unsigned int offset; + if (!st->struct_type()->backend_field_offset(this->gogo_, + farg->field_index(), + &offset)) + return false; + total_offset += offset; + if (farg->implicit() && struct_expr->field_reference_expression() != NULL) + { + // Go up until we reach the original base. + farg = struct_expr->field_reference_expression(); + continue; + } + break; + } + nc->set_unsigned_long(Type::lookup_integer_type("uintptr"), + static_cast<unsigned long>(total_offset)); + return true; + } + else if (this->code_ == BUILTIN_REAL || this->code_ == BUILTIN_IMAG) + { + Expression* arg = this->one_arg(); + if (arg == NULL) + return false; + + Numeric_constant argnc; + if (!arg->numeric_constant_value(&argnc)) + return false; + + mpfr_t real; + mpfr_t imag; + if (!argnc.to_complex(&real, &imag)) + return false; + + Type* type = Builtin_call_expression::real_imag_type(argnc.type()); + if (this->code_ == BUILTIN_REAL) + nc->set_float(type, real); + else + nc->set_float(type, imag); + return true; + } + else if (this->code_ == BUILTIN_COMPLEX) + { + const Expression_list* args = this->args(); + if (args == NULL || args->size() != 2) + return false; + + Numeric_constant rnc; + if (!args->front()->numeric_constant_value(&rnc)) + return false; + Numeric_constant inc; + if (!args->back()->numeric_constant_value(&inc)) + return false; + + if (rnc.type() != NULL + && !rnc.type()->is_abstract() + && inc.type() != NULL + && !inc.type()->is_abstract() + && !Type::are_identical(rnc.type(), inc.type(), false, NULL)) + return false; + + mpfr_t r; + if (!rnc.to_float(&r)) + return false; + mpfr_t i; + if (!inc.to_float(&i)) + { + mpfr_clear(r); + return false; + } + + Type* arg_type = rnc.type(); + if (arg_type == NULL || arg_type->is_abstract()) + arg_type = inc.type(); + + Type* type = Builtin_call_expression::complex_type(arg_type); + nc->set_complex(type, r, i); + + mpfr_clear(r); + mpfr_clear(i); + + return true; + } + + return false; +} + +// Give an error if we are discarding the value of an expression which +// should not normally be discarded. We don't give an error for +// discarding the value of an ordinary function call, but we do for +// builtin functions, purely for consistency with the gc compiler. + +bool +Builtin_call_expression::do_discarding_value() +{ + switch (this->code_) + { + case BUILTIN_INVALID: + default: + go_unreachable(); + + case BUILTIN_APPEND: + case BUILTIN_CAP: + case BUILTIN_COMPLEX: + case BUILTIN_IMAG: + case BUILTIN_LEN: + case BUILTIN_MAKE: + case BUILTIN_NEW: + case BUILTIN_REAL: + case BUILTIN_ALIGNOF: + case BUILTIN_OFFSETOF: + case BUILTIN_SIZEOF: + this->unused_value_error(); + return false; + + case BUILTIN_CLOSE: + case BUILTIN_COPY: + case BUILTIN_DELETE: + case BUILTIN_PANIC: + case BUILTIN_PRINT: + case BUILTIN_PRINTLN: + case BUILTIN_RECOVER: + return true; + } +} + +// Return the type. + +Type* +Builtin_call_expression::do_type() +{ + switch (this->code_) + { + case BUILTIN_INVALID: + default: + go_unreachable(); + + case BUILTIN_NEW: + case BUILTIN_MAKE: + { + const Expression_list* args = this->args(); + if (args == NULL || args->empty()) + return Type::make_error_type(); + return Type::make_pointer_type(args->front()->type()); + } + + case BUILTIN_CAP: + case BUILTIN_COPY: + case BUILTIN_LEN: + return Type::lookup_integer_type("int"); + + case BUILTIN_ALIGNOF: + case BUILTIN_OFFSETOF: + case BUILTIN_SIZEOF: + return Type::lookup_integer_type("uintptr"); + + case BUILTIN_CLOSE: + case BUILTIN_DELETE: + case BUILTIN_PANIC: + case BUILTIN_PRINT: + case BUILTIN_PRINTLN: + return Type::make_void_type(); + + case BUILTIN_RECOVER: + return Type::make_empty_interface_type(Linemap::predeclared_location()); + + case BUILTIN_APPEND: + { + const Expression_list* args = this->args(); + if (args == NULL || args->empty()) + return Type::make_error_type(); + Type *ret = args->front()->type(); + if (!ret->is_slice_type()) + return Type::make_error_type(); + return ret; + } + + case BUILTIN_REAL: + case BUILTIN_IMAG: + { + Expression* arg = this->one_arg(); + if (arg == NULL) + return Type::make_error_type(); + Type* t = arg->type(); + if (t->is_abstract()) + t = t->make_non_abstract_type(); + t = Builtin_call_expression::real_imag_type(t); + if (t == NULL) + t = Type::make_error_type(); + return t; + } + + case BUILTIN_COMPLEX: + { + const Expression_list* args = this->args(); + if (args == NULL || args->size() != 2) + return Type::make_error_type(); + Type* t = args->front()->type(); + if (t->is_abstract()) + { + t = args->back()->type(); + if (t->is_abstract()) + t = t->make_non_abstract_type(); + } + t = Builtin_call_expression::complex_type(t); + if (t == NULL) + t = Type::make_error_type(); + return t; + } + } +} + +// Determine the type. + +void +Builtin_call_expression::do_determine_type(const Type_context* context) +{ + if (!this->determining_types()) + return; + + this->fn()->determine_type_no_context(); + + const Expression_list* args = this->args(); + + bool is_print; + Type* arg_type = NULL; + switch (this->code_) + { + case BUILTIN_PRINT: + case BUILTIN_PRINTLN: + // Do not force a large integer constant to "int". + is_print = true; + break; + + case BUILTIN_REAL: + case BUILTIN_IMAG: + arg_type = Builtin_call_expression::complex_type(context->type); + if (arg_type == NULL) + arg_type = Type::lookup_complex_type("complex128"); + is_print = false; + break; + + case BUILTIN_COMPLEX: + { + // For the complex function the type of one operand can + // determine the type of the other, as in a binary expression. + arg_type = Builtin_call_expression::real_imag_type(context->type); + if (arg_type == NULL) + arg_type = Type::lookup_float_type("float64"); + if (args != NULL && args->size() == 2) + { + Type* t1 = args->front()->type(); + Type* t2 = args->back()->type(); + if (!t1->is_abstract()) + arg_type = t1; + else if (!t2->is_abstract()) + arg_type = t2; + } + is_print = false; + } + break; + + default: + is_print = false; + break; + } + + if (args != NULL) + { + for (Expression_list::const_iterator pa = args->begin(); + pa != args->end(); + ++pa) + { + Type_context subcontext; + subcontext.type = arg_type; + + if (is_print) + { + // We want to print large constants, we so can't just + // use the appropriate nonabstract type. Use uint64 for + // an integer if we know it is nonnegative, otherwise + // use int64 for a integer, otherwise use float64 for a + // float or complex128 for a complex. + Type* want_type = NULL; + Type* atype = (*pa)->type(); + if (atype->is_abstract()) + { + if (atype->integer_type() != NULL) + { + Numeric_constant nc; + if (this->numeric_constant_value(&nc)) + { + mpz_t val; + if (nc.to_int(&val)) + { + if (mpz_sgn(val) >= 0) + want_type = Type::lookup_integer_type("uint64"); + mpz_clear(val); + } + } + if (want_type == NULL) + want_type = Type::lookup_integer_type("int64"); + } + else if (atype->float_type() != NULL) + want_type = Type::lookup_float_type("float64"); + else if (atype->complex_type() != NULL) + want_type = Type::lookup_complex_type("complex128"); + else if (atype->is_abstract_string_type()) + want_type = Type::lookup_string_type(); + else if (atype->is_abstract_boolean_type()) + want_type = Type::lookup_bool_type(); + else + go_unreachable(); + subcontext.type = want_type; + } + } + + (*pa)->determine_type(&subcontext); + } + } +} + +// If there is exactly one argument, return true. Otherwise give an +// error message and return false. + +bool +Builtin_call_expression::check_one_arg() +{ + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 1) + { + this->report_error(_("not enough arguments")); + return false; + } + else if (args->size() > 1) + { + this->report_error(_("too many arguments")); + return false; + } + if (args->front()->is_error_expression() + || args->front()->type()->is_error()) + { + this->set_is_error(); + return false; + } + return true; +} + +// Check argument types for a builtin function. + +void +Builtin_call_expression::do_check_types(Gogo*) +{ + if (this->is_error_expression()) + return; + switch (this->code_) + { + case BUILTIN_INVALID: + case BUILTIN_NEW: + case BUILTIN_MAKE: + case BUILTIN_DELETE: + return; + + case BUILTIN_LEN: + case BUILTIN_CAP: + { + // The single argument may be either a string or an array or a + // map or a channel, or a pointer to a closed array. + if (this->check_one_arg()) + { + Type* arg_type = this->one_arg()->type(); + if (arg_type->points_to() != NULL + && arg_type->points_to()->array_type() != NULL + && !arg_type->points_to()->is_slice_type()) + arg_type = arg_type->points_to(); + if (this->code_ == BUILTIN_CAP) + { + if (!arg_type->is_error() + && arg_type->array_type() == NULL + && arg_type->channel_type() == NULL) + this->report_error(_("argument must be array or slice " + "or channel")); + } + else + { + if (!arg_type->is_error() + && !arg_type->is_string_type() + && arg_type->array_type() == NULL + && arg_type->map_type() == NULL + && arg_type->channel_type() == NULL) + this->report_error(_("argument must be string or " + "array or slice or map or channel")); + } + } + } + break; + + case BUILTIN_PRINT: + case BUILTIN_PRINTLN: + { + const Expression_list* args = this->args(); + if (args == NULL) + { + if (this->code_ == BUILTIN_PRINT) + warning_at(this->location(), 0, + "no arguments for builtin function %<%s%>", + (this->code_ == BUILTIN_PRINT + ? "print" + : "println")); + } + else + { + for (Expression_list::const_iterator p = args->begin(); + p != args->end(); + ++p) + { + Type* type = (*p)->type(); + if (type->is_error() + || type->is_string_type() + || type->integer_type() != NULL + || type->float_type() != NULL + || type->complex_type() != NULL + || type->is_boolean_type() + || type->points_to() != NULL + || type->interface_type() != NULL + || type->channel_type() != NULL + || type->map_type() != NULL + || type->function_type() != NULL + || type->is_slice_type()) + ; + else if ((*p)->is_type_expression()) + { + // If this is a type expression it's going to give + // an error anyhow, so we don't need one here. + } + else + this->report_error(_("unsupported argument type to " + "builtin function")); + } + } + } + break; + + case BUILTIN_CLOSE: + if (this->check_one_arg()) + { + if (this->one_arg()->type()->channel_type() == NULL) + this->report_error(_("argument must be channel")); + else if (!this->one_arg()->type()->channel_type()->may_send()) + this->report_error(_("cannot close receive-only channel")); + } + break; + + case BUILTIN_PANIC: + case BUILTIN_SIZEOF: + case BUILTIN_ALIGNOF: + this->check_one_arg(); + break; + + case BUILTIN_RECOVER: + if (this->args() != NULL && !this->args()->empty()) + this->report_error(_("too many arguments")); + break; + + case BUILTIN_OFFSETOF: + if (this->check_one_arg()) + { + Expression* arg = this->one_arg(); + if (arg->field_reference_expression() == NULL) + this->report_error(_("argument must be a field reference")); + } + break; + + case BUILTIN_COPY: + { + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 2) + { + this->report_error(_("not enough arguments")); + break; + } + else if (args->size() > 2) + { + this->report_error(_("too many arguments")); + break; + } + Type* arg1_type = args->front()->type(); + Type* arg2_type = args->back()->type(); + if (arg1_type->is_error() || arg2_type->is_error()) + break; + + Type* e1; + if (arg1_type->is_slice_type()) + e1 = arg1_type->array_type()->element_type(); + else + { + this->report_error(_("left argument must be a slice")); + break; + } + + if (arg2_type->is_slice_type()) + { + Type* e2 = arg2_type->array_type()->element_type(); + if (!Type::are_identical(e1, e2, true, NULL)) + this->report_error(_("element types must be the same")); + } + else if (arg2_type->is_string_type()) + { + if (e1->integer_type() == NULL || !e1->integer_type()->is_byte()) + this->report_error(_("first argument must be []byte")); + } + else + this->report_error(_("second argument must be slice or string")); + } + break; + + case BUILTIN_APPEND: + { + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 2) + { + this->report_error(_("not enough arguments")); + break; + } + if (args->size() > 2) + { + this->report_error(_("too many arguments")); + break; + } + if (args->front()->type()->is_error() + || args->back()->type()->is_error()) + break; + + Array_type* at = args->front()->type()->array_type(); + Type* e = at->element_type(); + + // The language permits appending a string to a []byte, as a + // special case. + if (args->back()->type()->is_string_type()) + { + if (e->integer_type() != NULL && e->integer_type()->is_byte()) + break; + } + + // The language says that the second argument must be + // assignable to a slice of the element type of the first + // argument. We already know the first argument is a slice + // type. + Type* arg2_type = Type::make_array_type(e, NULL); + std::string reason; + if (!Type::are_assignable(arg2_type, args->back()->type(), &reason)) + { + if (reason.empty()) + this->report_error(_("argument 2 has invalid type")); + else + { + error_at(this->location(), "argument 2 has invalid type (%s)", + reason.c_str()); + this->set_is_error(); + } + } + break; + } + + case BUILTIN_REAL: + case BUILTIN_IMAG: + if (this->check_one_arg()) + { + if (this->one_arg()->type()->complex_type() == NULL) + this->report_error(_("argument must have complex type")); + } + break; + + case BUILTIN_COMPLEX: + { + const Expression_list* args = this->args(); + if (args == NULL || args->size() < 2) + this->report_error(_("not enough arguments")); + else if (args->size() > 2) + this->report_error(_("too many arguments")); + else if (args->front()->is_error_expression() + || args->front()->type()->is_error() + || args->back()->is_error_expression() + || args->back()->type()->is_error()) + this->set_is_error(); + else if (!Type::are_identical(args->front()->type(), + args->back()->type(), true, NULL)) + this->report_error(_("complex arguments must have identical types")); + else if (args->front()->type()->float_type() == NULL) + this->report_error(_("complex arguments must have " + "floating-point type")); + } + break; + + default: + go_unreachable(); + } +} + +// Return the tree for a builtin function. + +tree +Builtin_call_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Location location = this->location(); + switch (this->code_) + { + case BUILTIN_INVALID: + case BUILTIN_NEW: + case BUILTIN_MAKE: + go_unreachable(); + + case BUILTIN_LEN: + case BUILTIN_CAP: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 1); + Expression* arg = *args->begin(); + Type* arg_type = arg->type(); + + if (this->seen_) + { + go_assert(saw_errors()); + return error_mark_node; + } + this->seen_ = true; + + tree arg_tree = arg->get_tree(context); + + this->seen_ = false; + + if (arg_tree == error_mark_node) + return error_mark_node; + + if (arg_type->points_to() != NULL) + { + arg_type = arg_type->points_to(); + go_assert(arg_type->array_type() != NULL + && !arg_type->is_slice_type()); + go_assert(POINTER_TYPE_P(TREE_TYPE(arg_tree))); + arg_tree = build_fold_indirect_ref(arg_tree); + } + + Type* int_type = Type::lookup_integer_type("int"); + tree int_type_tree = type_to_tree(int_type->get_backend(gogo)); + + tree val_tree; + if (this->code_ == BUILTIN_LEN) + { + if (arg_type->is_string_type()) + val_tree = String_type::length_tree(gogo, arg_tree); + else if (arg_type->array_type() != NULL) + { + if (this->seen_) + { + go_assert(saw_errors()); + return error_mark_node; + } + this->seen_ = true; + Expression* len = arg_type->array_type()->get_length(gogo, arg); + val_tree = len->get_tree(context); + this->seen_ = false; + } + else if (arg_type->map_type() != NULL) + { + tree arg_type_tree = type_to_tree(arg_type->get_backend(gogo)); + static tree map_len_fndecl; + val_tree = Gogo::call_builtin(&map_len_fndecl, + location, + "__go_map_len", + 1, + int_type_tree, + arg_type_tree, + arg_tree); + } + else if (arg_type->channel_type() != NULL) + { + tree arg_type_tree = type_to_tree(arg_type->get_backend(gogo)); + static tree chan_len_fndecl; + val_tree = Gogo::call_builtin(&chan_len_fndecl, + location, + "__go_chan_len", + 1, + int_type_tree, + arg_type_tree, + arg_tree); + } + else + go_unreachable(); + } + else + { + if (arg_type->array_type() != NULL) + { + if (this->seen_) + { + go_assert(saw_errors()); + return error_mark_node; + } + this->seen_ = true; + Expression* cap = + arg_type->array_type()->get_capacity(gogo, arg); + val_tree = cap->get_tree(context); + this->seen_ = false; + } + else if (arg_type->channel_type() != NULL) + { + tree arg_type_tree = type_to_tree(arg_type->get_backend(gogo)); + static tree chan_cap_fndecl; + val_tree = Gogo::call_builtin(&chan_cap_fndecl, + location, + "__go_chan_cap", + 1, + int_type_tree, + arg_type_tree, + arg_tree); + } + else + go_unreachable(); + } + + return fold_convert_loc(location.gcc_location(), int_type_tree, + val_tree); + } + + case BUILTIN_PRINT: + case BUILTIN_PRINTLN: + { + const bool is_ln = this->code_ == BUILTIN_PRINTLN; + tree stmt_list = NULL_TREE; + + const Expression_list* call_args = this->args(); + if (call_args != NULL) + { + for (Expression_list::const_iterator p = call_args->begin(); + p != call_args->end(); + ++p) + { + if (is_ln && p != call_args->begin()) + { + static tree print_space_fndecl; + tree call = Gogo::call_builtin(&print_space_fndecl, + location, + "__go_print_space", + 0, + void_type_node); + if (call == error_mark_node) + return error_mark_node; + append_to_statement_list(call, &stmt_list); + } + + Type* type = (*p)->type(); + + tree arg = (*p)->get_tree(context); + if (arg == error_mark_node) + return error_mark_node; + + tree* pfndecl; + const char* fnname; + if (type->is_string_type()) + { + static tree print_string_fndecl; + pfndecl = &print_string_fndecl; + fnname = "__go_print_string"; + } + else if (type->integer_type() != NULL + && type->integer_type()->is_unsigned()) + { + static tree print_uint64_fndecl; + pfndecl = &print_uint64_fndecl; + fnname = "__go_print_uint64"; + Type* itype = Type::lookup_integer_type("uint64"); + Btype* bitype = itype->get_backend(gogo); + arg = fold_convert_loc(location.gcc_location(), + type_to_tree(bitype), arg); + } + else if (type->integer_type() != NULL) + { + static tree print_int64_fndecl; + pfndecl = &print_int64_fndecl; + fnname = "__go_print_int64"; + Type* itype = Type::lookup_integer_type("int64"); + Btype* bitype = itype->get_backend(gogo); + arg = fold_convert_loc(location.gcc_location(), + type_to_tree(bitype), arg); + } + else if (type->float_type() != NULL) + { + static tree print_double_fndecl; + pfndecl = &print_double_fndecl; + fnname = "__go_print_double"; + arg = fold_convert_loc(location.gcc_location(), + double_type_node, arg); + } + else if (type->complex_type() != NULL) + { + static tree print_complex_fndecl; + pfndecl = &print_complex_fndecl; + fnname = "__go_print_complex"; + arg = fold_convert_loc(location.gcc_location(), + complex_double_type_node, arg); + } + else if (type->is_boolean_type()) + { + static tree print_bool_fndecl; + pfndecl = &print_bool_fndecl; + fnname = "__go_print_bool"; + } + else if (type->points_to() != NULL + || type->channel_type() != NULL + || type->map_type() != NULL + || type->function_type() != NULL) + { + static tree print_pointer_fndecl; + pfndecl = &print_pointer_fndecl; + fnname = "__go_print_pointer"; + arg = fold_convert_loc(location.gcc_location(), + ptr_type_node, arg); + } + else if (type->interface_type() != NULL) + { + if (type->interface_type()->is_empty()) + { + static tree print_empty_interface_fndecl; + pfndecl = &print_empty_interface_fndecl; + fnname = "__go_print_empty_interface"; + } + else + { + static tree print_interface_fndecl; + pfndecl = &print_interface_fndecl; + fnname = "__go_print_interface"; + } + } + else if (type->is_slice_type()) + { + static tree print_slice_fndecl; + pfndecl = &print_slice_fndecl; + fnname = "__go_print_slice"; + } + else + { + go_assert(saw_errors()); + return error_mark_node; + } + + tree call = Gogo::call_builtin(pfndecl, + location, + fnname, + 1, + void_type_node, + TREE_TYPE(arg), + arg); + if (call == error_mark_node) + return error_mark_node; + append_to_statement_list(call, &stmt_list); + } + } + + if (is_ln) + { + static tree print_nl_fndecl; + tree call = Gogo::call_builtin(&print_nl_fndecl, + location, + "__go_print_nl", + 0, + void_type_node); + if (call == error_mark_node) + return error_mark_node; + append_to_statement_list(call, &stmt_list); + } + + return stmt_list; + } + + case BUILTIN_PANIC: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 1); + Expression* arg = args->front(); + tree arg_tree = arg->get_tree(context); + if (arg_tree == error_mark_node) + return error_mark_node; + Type *empty = + Type::make_empty_interface_type(Linemap::predeclared_location()); + arg_tree = Expression::convert_for_assignment(context, empty, + arg->type(), + arg_tree, location); + static tree panic_fndecl; + tree call = Gogo::call_builtin(&panic_fndecl, + location, + "__go_panic", + 1, + void_type_node, + TREE_TYPE(arg_tree), + arg_tree); + if (call == error_mark_node) + return error_mark_node; + // This function will throw an exception. + TREE_NOTHROW(panic_fndecl) = 0; + // This function will not return. + TREE_THIS_VOLATILE(panic_fndecl) = 1; + return call; + } + + case BUILTIN_RECOVER: + { + // The argument is set when building recover thunks. It's a + // boolean value which is true if we can recover a value now. + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 1); + Expression* arg = args->front(); + tree arg_tree = arg->get_tree(context); + if (arg_tree == error_mark_node) + return error_mark_node; + + Type *empty = + Type::make_empty_interface_type(Linemap::predeclared_location()); + tree empty_tree = type_to_tree(empty->get_backend(context->gogo())); + + Type* nil_type = Type::make_nil_type(); + Expression* nil = Expression::make_nil(location); + tree nil_tree = nil->get_tree(context); + tree empty_nil_tree = Expression::convert_for_assignment(context, + empty, + nil_type, + nil_tree, + location); + + // We need to handle a deferred call to recover specially, + // because it changes whether it can recover a panic or not. + // See test7 in test/recover1.go. + tree call; + if (this->is_deferred()) + { + static tree deferred_recover_fndecl; + call = Gogo::call_builtin(&deferred_recover_fndecl, + location, + "__go_deferred_recover", + 0, + empty_tree); + } + else + { + static tree recover_fndecl; + call = Gogo::call_builtin(&recover_fndecl, + location, + "__go_recover", + 0, + empty_tree); + } + if (call == error_mark_node) + return error_mark_node; + return fold_build3_loc(location.gcc_location(), COND_EXPR, empty_tree, + arg_tree, call, empty_nil_tree); + } + + case BUILTIN_CLOSE: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 1); + Expression* arg = args->front(); + tree arg_tree = arg->get_tree(context); + if (arg_tree == error_mark_node) + return error_mark_node; + static tree close_fndecl; + return Gogo::call_builtin(&close_fndecl, + location, + "__go_builtin_close", + 1, + void_type_node, + TREE_TYPE(arg_tree), + arg_tree); + } + + case BUILTIN_SIZEOF: + case BUILTIN_OFFSETOF: + case BUILTIN_ALIGNOF: + { + Numeric_constant nc; + unsigned long val; + if (!this->numeric_constant_value(&nc) + || nc.to_unsigned_long(&val) != Numeric_constant::NC_UL_VALID) + { + go_assert(saw_errors()); + return error_mark_node; + } + Type* uintptr_type = Type::lookup_integer_type("uintptr"); + tree type = type_to_tree(uintptr_type->get_backend(gogo)); + return build_int_cst(type, val); + } + + case BUILTIN_COPY: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 2); + Expression* arg1 = args->front(); + Expression* arg2 = args->back(); + + tree arg1_tree = arg1->get_tree(context); + tree arg2_tree = arg2->get_tree(context); + if (arg1_tree == error_mark_node || arg2_tree == error_mark_node) + return error_mark_node; + + Type* arg1_type = arg1->type(); + Array_type* at = arg1_type->array_type(); + go_assert(arg1->is_variable()); + Expression* arg1_valptr = at->get_value_pointer(gogo, arg1); + Expression* arg1_len_expr = at->get_length(gogo, arg1); + tree arg1_val = arg1_valptr->get_tree(context); + tree arg1_len = arg1_len_expr->get_tree(context); + if (arg1_val == error_mark_node || arg1_len == error_mark_node) + return error_mark_node; + + Type* arg2_type = arg2->type(); + tree arg2_val; + tree arg2_len; + if (arg2_type->is_slice_type()) + { + at = arg2_type->array_type(); + go_assert(arg2->is_variable()); + Expression* arg2_valptr = at->get_value_pointer(gogo, arg2); + Expression* arg2_len_expr = at->get_length(gogo, arg2); + arg2_val = arg2_valptr->get_tree(context); + arg2_len = arg2_len_expr->get_tree(context); + } + else + { + arg2_tree = save_expr(arg2_tree); + arg2_val = String_type::bytes_tree(gogo, arg2_tree); + arg2_len = String_type::length_tree(gogo, arg2_tree); + } + if (arg2_val == error_mark_node || arg2_len == error_mark_node) + return error_mark_node; + + arg1_len = save_expr(arg1_len); + arg2_len = save_expr(arg2_len); + tree len = fold_build3_loc(location.gcc_location(), COND_EXPR, + TREE_TYPE(arg1_len), + fold_build2_loc(location.gcc_location(), + LT_EXPR, boolean_type_node, + arg1_len, arg2_len), + arg1_len, arg2_len); + len = save_expr(len); + + Type* element_type = at->element_type(); + Btype* element_btype = element_type->get_backend(gogo); + tree element_type_tree = type_to_tree(element_btype); + if (element_type_tree == error_mark_node) + return error_mark_node; + tree element_size = TYPE_SIZE_UNIT(element_type_tree); + tree bytecount = fold_convert_loc(location.gcc_location(), + TREE_TYPE(element_size), len); + bytecount = fold_build2_loc(location.gcc_location(), MULT_EXPR, + TREE_TYPE(element_size), + bytecount, element_size); + bytecount = fold_convert_loc(location.gcc_location(), size_type_node, + bytecount); + + arg1_val = fold_convert_loc(location.gcc_location(), ptr_type_node, + arg1_val); + arg2_val = fold_convert_loc(location.gcc_location(), ptr_type_node, + arg2_val); + + static tree copy_fndecl; + tree call = Gogo::call_builtin(©_fndecl, + location, + "__go_copy", + 3, + void_type_node, + ptr_type_node, + arg1_val, + ptr_type_node, + arg2_val, + size_type_node, + bytecount); + if (call == error_mark_node) + return error_mark_node; + + return fold_build2_loc(location.gcc_location(), COMPOUND_EXPR, + TREE_TYPE(len), call, len); + } + + case BUILTIN_APPEND: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 2); + Expression* arg1 = args->front(); + Expression* arg2 = args->back(); + + tree arg1_tree = arg1->get_tree(context); + tree arg2_tree = arg2->get_tree(context); + if (arg1_tree == error_mark_node || arg2_tree == error_mark_node) + return error_mark_node; + + Array_type* at = arg1->type()->array_type(); + Type* element_type = at->element_type()->forwarded(); + + tree arg2_val; + tree arg2_len; + tree element_size; + if (arg2->type()->is_string_type() + && element_type->integer_type() != NULL + && element_type->integer_type()->is_byte()) + { + arg2_tree = save_expr(arg2_tree); + arg2_val = String_type::bytes_tree(gogo, arg2_tree); + arg2_len = String_type::length_tree(gogo, arg2_tree); + element_size = size_int(1); + } + else + { + go_assert(arg2->is_variable()); + arg2_val = + at->get_value_pointer(gogo, arg2)->get_tree(context); + arg2_len = at->get_length(gogo, arg2)->get_tree(context); + Btype* element_btype = element_type->get_backend(gogo); + tree element_type_tree = type_to_tree(element_btype); + if (element_type_tree == error_mark_node) + return error_mark_node; + element_size = TYPE_SIZE_UNIT(element_type_tree); + } + + arg2_val = fold_convert_loc(location.gcc_location(), ptr_type_node, + arg2_val); + arg2_len = fold_convert_loc(location.gcc_location(), size_type_node, + arg2_len); + element_size = fold_convert_loc(location.gcc_location(), size_type_node, + element_size); + + if (arg2_val == error_mark_node + || arg2_len == error_mark_node + || element_size == error_mark_node) + return error_mark_node; + + // We rebuild the decl each time since the slice types may + // change. + tree append_fndecl = NULL_TREE; + return Gogo::call_builtin(&append_fndecl, + location, + "__go_append", + 4, + TREE_TYPE(arg1_tree), + TREE_TYPE(arg1_tree), + arg1_tree, + ptr_type_node, + arg2_val, + size_type_node, + arg2_len, + size_type_node, + element_size); + } + + case BUILTIN_REAL: + case BUILTIN_IMAG: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 1); + Expression* arg = args->front(); + tree arg_tree = arg->get_tree(context); + if (arg_tree == error_mark_node) + return error_mark_node; + go_assert(COMPLEX_FLOAT_TYPE_P(TREE_TYPE(arg_tree))); + if (this->code_ == BUILTIN_REAL) + return fold_build1_loc(location.gcc_location(), REALPART_EXPR, + TREE_TYPE(TREE_TYPE(arg_tree)), + arg_tree); + else + return fold_build1_loc(location.gcc_location(), IMAGPART_EXPR, + TREE_TYPE(TREE_TYPE(arg_tree)), + arg_tree); + } + + case BUILTIN_COMPLEX: + { + const Expression_list* args = this->args(); + go_assert(args != NULL && args->size() == 2); + tree r = args->front()->get_tree(context); + tree i = args->back()->get_tree(context); + if (r == error_mark_node || i == error_mark_node) + return error_mark_node; + go_assert(TYPE_MAIN_VARIANT(TREE_TYPE(r)) + == TYPE_MAIN_VARIANT(TREE_TYPE(i))); + go_assert(SCALAR_FLOAT_TYPE_P(TREE_TYPE(r))); + return fold_build2_loc(location.gcc_location(), COMPLEX_EXPR, + build_complex_type(TREE_TYPE(r)), + r, i); + } + + default: + go_unreachable(); + } +} + +// We have to support exporting a builtin call expression, because +// code can set a constant to the result of a builtin expression. + +void +Builtin_call_expression::do_export(Export* exp) const +{ + Numeric_constant nc; + if (!this->numeric_constant_value(&nc)) + { + error_at(this->location(), "value is not constant"); + return; + } + + if (nc.is_int()) + { + mpz_t val; + nc.get_int(&val); + Integer_expression::export_integer(exp, val); + mpz_clear(val); + } + else if (nc.is_float()) + { + mpfr_t fval; + nc.get_float(&fval); + Float_expression::export_float(exp, fval); + mpfr_clear(fval); + } + else if (nc.is_complex()) + { + mpfr_t real; + mpfr_t imag; + Complex_expression::export_complex(exp, real, imag); + mpfr_clear(real); + mpfr_clear(imag); + } + else + go_unreachable(); + + // A trailing space lets us reliably identify the end of the number. + exp->write_c_string(" "); +} + +// Class Call_expression. + +// A Go function can be viewed in a couple of different ways. The +// code of a Go function becomes a backend function with parameters +// whose types are simply the backend representation of the Go types. +// If there are multiple results, they are returned as a backend +// struct. + +// However, when Go code refers to a function other than simply +// calling it, the backend type of that function is actually a struct. +// The first field of the struct points to the Go function code +// (sometimes a wrapper as described below). The remaining fields +// hold addresses of closed-over variables. This struct is called a +// closure. + +// There are a few cases to consider. + +// A direct function call of a known function in package scope. In +// this case there are no closed-over variables, and we know the name +// of the function code. We can simply produce a backend call to the +// function directly, and not worry about the closure. + +// A direct function call of a known function literal. In this case +// we know the function code and we know the closure. We generate the +// function code such that it expects an additional final argument of +// the closure type. We pass the closure as the last argument, after +// the other arguments. + +// An indirect function call. In this case we have a closure. We +// load the pointer to the function code from the first field of the +// closure. We pass the address of the closure as the last argument. + +// A call to a method of an interface. Type methods are always at +// package scope, so we call the function directly, and don't worry +// about the closure. + +// This means that for a function at package scope we have two cases. +// One is the direct call, which has no closure. The other is the +// indirect call, which does have a closure. We can't simply ignore +// the closure, even though it is the last argument, because that will +// fail on targets where the function pops its arguments. So when +// generating a closure for a package-scope function we set the +// function code pointer in the closure to point to a wrapper +// function. This wrapper function accepts a final argument that +// points to the closure, ignores it, and calls the real function as a +// direct function call. This wrapper will normally be efficient, and +// can often simply be a tail call to the real function. + +// We don't use GCC's static chain pointer because 1) we don't need +// it; 2) GCC only permits using a static chain to call a known +// function, so we can't use it for an indirect call anyhow. Since we +// can't use it for an indirect call, we may as well not worry about +// using it for a direct call either. + +// We pass the closure last rather than first because it means that +// the function wrapper we put into a closure for a package-scope +// function can normally just be a tail call to the real function. + +// For method expressions we generate a wrapper that loads the +// receiver from the closure and then calls the method. This +// unfortunately forces reshuffling the arguments, since there is a +// new first argument, but we can't avoid reshuffling either for +// method expressions or for indirect calls of package-scope +// functions, and since the latter are more common we reshuffle for +// method expressions. + +// Note that the Go code retains the Go types. The extra final +// argument only appears when we convert to the backend +// representation. + +// Traversal. + +int +Call_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->fn_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->args_ != NULL) + { + if (this->args_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Lower a call statement. + +Expression* +Call_expression::do_lower(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, int) +{ + Location loc = this->location(); + + // A type cast can look like a function call. + if (this->fn_->is_type_expression() + && this->args_ != NULL + && this->args_->size() == 1) + return Expression::make_cast(this->fn_->type(), this->args_->front(), + loc); + + // Because do_type will return an error type and thus prevent future + // errors, check for that case now to ensure that the error gets + // reported. + Function_type* fntype = this->get_function_type(); + if (fntype == NULL) + { + if (!this->fn_->type()->is_error()) + this->report_error(_("expected function")); + return Expression::make_error(loc); + } + + // Handle an argument which is a call to a function which returns + // multiple results. + if (this->args_ != NULL + && this->args_->size() == 1 + && this->args_->front()->call_expression() != NULL) + { + size_t rc = this->args_->front()->call_expression()->result_count(); + if (rc > 1 + && ((fntype->parameters() != NULL + && (fntype->parameters()->size() == rc + || (fntype->is_varargs() + && fntype->parameters()->size() - 1 <= rc))) + || fntype->is_builtin())) + { + Call_expression* call = this->args_->front()->call_expression(); + Expression_list* args = new Expression_list; + for (size_t i = 0; i < rc; ++i) + args->push_back(Expression::make_call_result(call, i)); + // We can't return a new call expression here, because this + // one may be referenced by Call_result expressions. We + // also can't delete the old arguments, because we may still + // traverse them somewhere up the call stack. FIXME. + this->args_ = args; + } + } + + // Recognize a call to a builtin function. + if (fntype->is_builtin()) + return new Builtin_call_expression(gogo, this->fn_, this->args_, + this->is_varargs_, loc); + + // If this call returns multiple results, create a temporary + // variable for each result. + size_t rc = this->result_count(); + if (rc > 1 && this->results_ == NULL) + { + std::vector<Temporary_statement*>* temps = + new std::vector<Temporary_statement*>; + temps->reserve(rc); + const Typed_identifier_list* results = fntype->results(); + for (Typed_identifier_list::const_iterator p = results->begin(); + p != results->end(); + ++p) + { + Temporary_statement* temp = Statement::make_temporary(p->type(), + NULL, loc); + inserter->insert(temp); + temps->push_back(temp); + } + this->results_ = temps; + } + + // Handle a call to a varargs function by packaging up the extra + // parameters. + if (fntype->is_varargs()) + { + const Typed_identifier_list* parameters = fntype->parameters(); + go_assert(parameters != NULL && !parameters->empty()); + Type* varargs_type = parameters->back().type(); + this->lower_varargs(gogo, function, inserter, varargs_type, + parameters->size()); + } + + // If this is call to a method, call the method directly passing the + // object as the first parameter. + Bound_method_expression* bme = this->fn_->bound_method_expression(); + if (bme != NULL) + { + Named_object* methodfn = bme->function(); + Expression* first_arg = bme->first_argument(); + + // We always pass a pointer when calling a method. + if (first_arg->type()->points_to() == NULL + && !first_arg->type()->is_error()) + { + first_arg = Expression::make_unary(OPERATOR_AND, first_arg, loc); + // We may need to create a temporary variable so that we can + // take the address. We can't do that here because it will + // mess up the order of evaluation. + Unary_expression* ue = static_cast<Unary_expression*>(first_arg); + ue->set_create_temp(); + } + + // If we are calling a method which was inherited from an + // embedded struct, and the method did not get a stub, then the + // first type may be wrong. + Type* fatype = bme->first_argument_type(); + if (fatype != NULL) + { + if (fatype->points_to() == NULL) + fatype = Type::make_pointer_type(fatype); + first_arg = Expression::make_unsafe_cast(fatype, first_arg, loc); + } + + Expression_list* new_args = new Expression_list(); + new_args->push_back(first_arg); + if (this->args_ != NULL) + { + for (Expression_list::const_iterator p = this->args_->begin(); + p != this->args_->end(); + ++p) + new_args->push_back(*p); + } + + // We have to change in place because this structure may be + // referenced by Call_result_expressions. We can't delete the + // old arguments, because we may be traversing them up in some + // caller. FIXME. + this->args_ = new_args; + this->fn_ = Expression::make_func_reference(methodfn, NULL, + bme->location()); + } + + return this; +} + +// Lower a call to a varargs function. FUNCTION is the function in +// which the call occurs--it's not the function we are calling. +// VARARGS_TYPE is the type of the varargs parameter, a slice type. +// PARAM_COUNT is the number of parameters of the function we are +// calling; the last of these parameters will be the varargs +// parameter. + +void +Call_expression::lower_varargs(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, + Type* varargs_type, size_t param_count) +{ + if (this->varargs_are_lowered_) + return; + + Location loc = this->location(); + + go_assert(param_count > 0); + go_assert(varargs_type->is_slice_type()); + + size_t arg_count = this->args_ == NULL ? 0 : this->args_->size(); + if (arg_count < param_count - 1) + { + // Not enough arguments; will be caught in check_types. + return; + } + + Expression_list* old_args = this->args_; + Expression_list* new_args = new Expression_list(); + bool push_empty_arg = false; + if (old_args == NULL || old_args->empty()) + { + go_assert(param_count == 1); + push_empty_arg = true; + } + else + { + Expression_list::const_iterator pa; + int i = 1; + for (pa = old_args->begin(); pa != old_args->end(); ++pa, ++i) + { + if (static_cast<size_t>(i) == param_count) + break; + new_args->push_back(*pa); + } + + // We have reached the varargs parameter. + + bool issued_error = false; + if (pa == old_args->end()) + push_empty_arg = true; + else if (pa + 1 == old_args->end() && this->is_varargs_) + new_args->push_back(*pa); + else if (this->is_varargs_) + { + if ((*pa)->type()->is_slice_type()) + this->report_error(_("too many arguments")); + else + { + error_at(this->location(), + _("invalid use of %<...%> with non-slice")); + this->set_is_error(); + } + return; + } + else + { + Type* element_type = varargs_type->array_type()->element_type(); + Expression_list* vals = new Expression_list; + for (; pa != old_args->end(); ++pa, ++i) + { + // Check types here so that we get a better message. + Type* patype = (*pa)->type(); + Location paloc = (*pa)->location(); + if (!this->check_argument_type(i, element_type, patype, + paloc, issued_error)) + continue; + vals->push_back(*pa); + } + Expression* val = + Expression::make_slice_composite_literal(varargs_type, vals, loc); + gogo->lower_expression(function, inserter, &val); + new_args->push_back(val); + } + } + + if (push_empty_arg) + new_args->push_back(Expression::make_nil(loc)); + + // We can't return a new call expression here, because this one may + // be referenced by Call_result expressions. FIXME. We can't + // delete OLD_ARGS because we may have both a Call_expression and a + // Builtin_call_expression which refer to them. FIXME. + this->args_ = new_args; + this->varargs_are_lowered_ = true; +} + +// Get the function type. This can return NULL in error cases. + +Function_type* +Call_expression::get_function_type() const +{ + return this->fn_->type()->function_type(); +} + +// Return the number of values which this call will return. + +size_t +Call_expression::result_count() const +{ + const Function_type* fntype = this->get_function_type(); + if (fntype == NULL) + return 0; + if (fntype->results() == NULL) + return 0; + return fntype->results()->size(); +} + +// Return the temporary which holds a result. + +Temporary_statement* +Call_expression::result(size_t i) const +{ + if (this->results_ == NULL || this->results_->size() <= i) + { + go_assert(saw_errors()); + return NULL; + } + return (*this->results_)[i]; +} + +// Return whether this is a call to the predeclared function recover. + +bool +Call_expression::is_recover_call() const +{ + return this->do_is_recover_call(); +} + +// Set the argument to the recover function. + +void +Call_expression::set_recover_arg(Expression* arg) +{ + this->do_set_recover_arg(arg); +} + +// Virtual functions also implemented by Builtin_call_expression. + +bool +Call_expression::do_is_recover_call() const +{ + return false; +} + +void +Call_expression::do_set_recover_arg(Expression*) +{ + go_unreachable(); +} + +// We have found an error with this call expression; return true if +// we should report it. + +bool +Call_expression::issue_error() +{ + if (this->issued_error_) + return false; + else + { + this->issued_error_ = true; + return true; + } +} + +// Get the type. + +Type* +Call_expression::do_type() +{ + if (this->type_ != NULL) + return this->type_; + + Type* ret; + Function_type* fntype = this->get_function_type(); + if (fntype == NULL) + return Type::make_error_type(); + + const Typed_identifier_list* results = fntype->results(); + if (results == NULL) + ret = Type::make_void_type(); + else if (results->size() == 1) + ret = results->begin()->type(); + else + ret = Type::make_call_multiple_result_type(this); + + this->type_ = ret; + + return this->type_; +} + +// Determine types for a call expression. We can use the function +// parameter types to set the types of the arguments. + +void +Call_expression::do_determine_type(const Type_context*) +{ + if (!this->determining_types()) + return; + + this->fn_->determine_type_no_context(); + Function_type* fntype = this->get_function_type(); + const Typed_identifier_list* parameters = NULL; + if (fntype != NULL) + parameters = fntype->parameters(); + if (this->args_ != NULL) + { + Typed_identifier_list::const_iterator pt; + if (parameters != NULL) + pt = parameters->begin(); + bool first = true; + for (Expression_list::const_iterator pa = this->args_->begin(); + pa != this->args_->end(); + ++pa) + { + if (first) + { + first = false; + // If this is a method, the first argument is the + // receiver. + if (fntype != NULL && fntype->is_method()) + { + Type* rtype = fntype->receiver()->type(); + // The receiver is always passed as a pointer. + if (rtype->points_to() == NULL) + rtype = Type::make_pointer_type(rtype); + Type_context subcontext(rtype, false); + (*pa)->determine_type(&subcontext); + continue; + } + } + + if (parameters != NULL && pt != parameters->end()) + { + Type_context subcontext(pt->type(), false); + (*pa)->determine_type(&subcontext); + ++pt; + } + else + (*pa)->determine_type_no_context(); + } + } +} + +// Called when determining types for a Call_expression. Return true +// if we should go ahead, false if they have already been determined. + +bool +Call_expression::determining_types() +{ + if (this->types_are_determined_) + return false; + else + { + this->types_are_determined_ = true; + return true; + } +} + +// Check types for parameter I. + +bool +Call_expression::check_argument_type(int i, const Type* parameter_type, + const Type* argument_type, + Location argument_location, + bool issued_error) +{ + std::string reason; + bool ok; + if (this->are_hidden_fields_ok_) + ok = Type::are_assignable_hidden_ok(parameter_type, argument_type, + &reason); + else + ok = Type::are_assignable(parameter_type, argument_type, &reason); + if (!ok) + { + if (!issued_error) + { + if (reason.empty()) + error_at(argument_location, "argument %d has incompatible type", i); + else + error_at(argument_location, + "argument %d has incompatible type (%s)", + i, reason.c_str()); + } + this->set_is_error(); + return false; + } + return true; +} + +// Check types. + +void +Call_expression::do_check_types(Gogo*) +{ + if (this->classification() == EXPRESSION_ERROR) + return; + + Function_type* fntype = this->get_function_type(); + if (fntype == NULL) + { + if (!this->fn_->type()->is_error()) + this->report_error(_("expected function")); + return; + } + + bool is_method = fntype->is_method(); + if (is_method) + { + go_assert(this->args_ != NULL && !this->args_->empty()); + Type* rtype = fntype->receiver()->type(); + Expression* first_arg = this->args_->front(); + // The language permits copying hidden fields for a method + // receiver. We dereference the values since receivers are + // always passed as pointers. + std::string reason; + if (!Type::are_assignable_hidden_ok(rtype->deref(), + first_arg->type()->deref(), + &reason)) + { + if (reason.empty()) + this->report_error(_("incompatible type for receiver")); + else + { + error_at(this->location(), + "incompatible type for receiver (%s)", + reason.c_str()); + this->set_is_error(); + } + } + } + + // Note that varargs was handled by the lower_varargs() method, so + // we don't have to worry about it here unless something is wrong. + if (this->is_varargs_ && !this->varargs_are_lowered_) + { + if (!fntype->is_varargs()) + { + error_at(this->location(), + _("invalid use of %<...%> calling non-variadic function")); + this->set_is_error(); + return; + } + } + + const Typed_identifier_list* parameters = fntype->parameters(); + if (this->args_ == NULL) + { + if (parameters != NULL && !parameters->empty()) + this->report_error(_("not enough arguments")); + } + else if (parameters == NULL) + { + if (!is_method || this->args_->size() > 1) + this->report_error(_("too many arguments")); + } + else + { + int i = 0; + Expression_list::const_iterator pa = this->args_->begin(); + if (is_method) + ++pa; + for (Typed_identifier_list::const_iterator pt = parameters->begin(); + pt != parameters->end(); + ++pt, ++pa, ++i) + { + if (pa == this->args_->end()) + { + this->report_error(_("not enough arguments")); + return; + } + this->check_argument_type(i + 1, pt->type(), (*pa)->type(), + (*pa)->location(), false); + } + if (pa != this->args_->end()) + this->report_error(_("too many arguments")); + } +} + +// Return whether we have to use a temporary variable to ensure that +// we evaluate this call expression in order. If the call returns no +// results then it will inevitably be executed last. + +bool +Call_expression::do_must_eval_in_order() const +{ + return this->result_count() > 0; +} + +// Get the function and the first argument to use when calling an +// interface method. + +Expression* +Call_expression::interface_method_function( + Interface_field_reference_expression* interface_method, + Expression** first_arg_ptr) +{ + *first_arg_ptr = interface_method->get_underlying_object(); + return interface_method->get_function(); +} + +// Build the call expression. + +tree +Call_expression::do_get_tree(Translate_context* context) +{ + if (this->tree_ != NULL_TREE) + return this->tree_; + + Function_type* fntype = this->get_function_type(); + if (fntype == NULL) + return error_mark_node; + + if (this->fn_->is_error_expression()) + return error_mark_node; + + Gogo* gogo = context->gogo(); + Location location = this->location(); + + Func_expression* func = this->fn_->func_expression(); + Interface_field_reference_expression* interface_method = + this->fn_->interface_field_reference_expression(); + const bool has_closure = func != NULL && func->closure() != NULL; + const bool is_interface_method = interface_method != NULL; + + bool has_closure_arg; + if (has_closure) + has_closure_arg = true; + else if (func != NULL) + has_closure_arg = false; + else if (is_interface_method) + has_closure_arg = false; + else + has_closure_arg = true; + + int nargs; + tree* args; + if (this->args_ == NULL || this->args_->empty()) + { + nargs = is_interface_method ? 1 : 0; + args = nargs == 0 ? NULL : new tree[nargs]; + } + else if (fntype->parameters() == NULL || fntype->parameters()->empty()) + { + // Passing a receiver parameter. + go_assert(!is_interface_method + && fntype->is_method() + && this->args_->size() == 1); + nargs = 1; + args = new tree[nargs]; + args[0] = this->args_->front()->get_tree(context); + } + else + { + const Typed_identifier_list* params = fntype->parameters(); + + nargs = this->args_->size(); + int i = is_interface_method ? 1 : 0; + nargs += i; + args = new tree[nargs]; + + Typed_identifier_list::const_iterator pp = params->begin(); + Expression_list::const_iterator pe = this->args_->begin(); + if (!is_interface_method && fntype->is_method()) + { + args[i] = (*pe)->get_tree(context); + ++pe; + ++i; + } + for (; pe != this->args_->end(); ++pe, ++pp, ++i) + { + go_assert(pp != params->end()); + tree arg_val = (*pe)->get_tree(context); + args[i] = Expression::convert_for_assignment(context, + pp->type(), + (*pe)->type(), + arg_val, + location); + if (args[i] == error_mark_node) + return error_mark_node; + } + go_assert(pp == params->end()); + go_assert(i == nargs); + } + + tree fntype_tree = type_to_tree(fntype->get_backend(gogo)); + tree fnfield_type = type_to_tree(fntype->get_backend_fntype(gogo)); + if (fntype_tree == error_mark_node || fnfield_type == error_mark_node) + return error_mark_node; + go_assert(FUNCTION_POINTER_TYPE_P(fnfield_type)); + tree rettype = TREE_TYPE(TREE_TYPE(fnfield_type)); + if (rettype == error_mark_node) + return error_mark_node; + + tree fn; + tree closure_tree; + if (func != NULL) + { + Named_object* no = func->named_object(); + fn = expr_to_tree(Func_expression::get_code_pointer(gogo, no, location)); + if (!has_closure) + closure_tree = NULL_TREE; + else + { + closure_tree = func->closure()->get_tree(context); + if (closure_tree == error_mark_node) + return error_mark_node; + } + } + else if (!is_interface_method) + { + closure_tree = this->fn_->get_tree(context); + if (closure_tree == error_mark_node) + return error_mark_node; + tree fnc = fold_convert_loc(location.gcc_location(), fntype_tree, + closure_tree); + go_assert(POINTER_TYPE_P(TREE_TYPE(fnc)) + && (TREE_CODE(TREE_TYPE(TREE_TYPE(fnc))) + == RECORD_TYPE)); + tree field = TYPE_FIELDS(TREE_TYPE(TREE_TYPE(fnc))); + fn = fold_build3_loc(location.gcc_location(), COMPONENT_REF, + TREE_TYPE(field), + build_fold_indirect_ref_loc(location.gcc_location(), + fnc), + field, NULL_TREE); + } + else + { + Expression* first_arg; + Expression* fn_expr = + this->interface_method_function(interface_method, &first_arg); + args[0] = first_arg->get_tree(context); + fn = fn_expr->get_tree(context); + + if (fn == error_mark_node) + return error_mark_node; + closure_tree = NULL_TREE; + } + + if (fn == error_mark_node || TREE_TYPE(fn) == error_mark_node) + return error_mark_node; + + tree fndecl = fn; + if (TREE_CODE(fndecl) == ADDR_EXPR) + fndecl = TREE_OPERAND(fndecl, 0); + + // Add a type cast in case the type of the function is a recursive + // type which refers to itself. We don't do this for an interface + // method because 1) an interface method never refers to itself, so + // we always have a function type here; 2) we pass an extra first + // argument to an interface method, so fnfield_type is not correct. + if ((!DECL_P(fndecl) || !DECL_IS_BUILTIN(fndecl)) && !is_interface_method) + fn = fold_convert_loc(location.gcc_location(), fnfield_type, fn); + + // This is to support builtin math functions when using 80387 math. + tree excess_type = NULL_TREE; + if (optimize + && TREE_CODE(fndecl) == FUNCTION_DECL + && DECL_IS_BUILTIN(fndecl) + && DECL_BUILT_IN_CLASS(fndecl) == BUILT_IN_NORMAL + && nargs > 0 + && ((SCALAR_FLOAT_TYPE_P(rettype) + && SCALAR_FLOAT_TYPE_P(TREE_TYPE(args[0]))) + || (COMPLEX_FLOAT_TYPE_P(rettype) + && COMPLEX_FLOAT_TYPE_P(TREE_TYPE(args[0]))))) + { + excess_type = excess_precision_type(TREE_TYPE(args[0])); + if (excess_type != NULL_TREE) + { + tree excess_fndecl = mathfn_built_in(excess_type, + DECL_FUNCTION_CODE(fndecl)); + if (excess_fndecl == NULL_TREE) + excess_type = NULL_TREE; + else + { + fn = build_fold_addr_expr_loc(location.gcc_location(), + excess_fndecl); + for (int i = 0; i < nargs; ++i) + { + if (SCALAR_FLOAT_TYPE_P(TREE_TYPE(args[i])) + || COMPLEX_FLOAT_TYPE_P(TREE_TYPE(args[i]))) + args[i] = ::convert(excess_type, args[i]); + } + } + } + } + + if (func == NULL) + fn = save_expr(fn); + + if (!has_closure_arg) + go_assert(closure_tree == NULL_TREE); + else + { + // Pass the closure argument by calling the function function + // __go_set_closure. In the order_evaluations pass we have + // ensured that if any parameters contain call expressions, they + // will have been moved out to temporary variables. + + go_assert(closure_tree != NULL_TREE); + closure_tree = fold_convert_loc(location.gcc_location(), ptr_type_node, + closure_tree); + static tree set_closure_fndecl; + tree set_closure = Gogo::call_builtin(&set_closure_fndecl, + location, + "__go_set_closure", + 1, + void_type_node, + ptr_type_node, + closure_tree); + if (set_closure == error_mark_node) + return error_mark_node; + fn = build2_loc(location.gcc_location(), COMPOUND_EXPR, + TREE_TYPE(fn), set_closure, fn); + } + + tree ret = build_call_array(excess_type != NULL_TREE ? excess_type : rettype, + fn, nargs, args); + delete[] args; + + SET_EXPR_LOCATION(ret, location.gcc_location()); + + // If this is a recursive function type which returns itself, as in + // type F func() F + // we have used ptr_type_node for the return type. Add a cast here + // to the correct type. + if (TREE_TYPE(ret) == ptr_type_node) + { + tree t = type_to_tree(this->type()->base()->get_backend(gogo)); + ret = fold_convert_loc(location.gcc_location(), t, ret); + } + + if (excess_type != NULL_TREE) + { + // Calling convert here can undo our excess precision change. + // That may or may not be a bug in convert_to_real. + ret = build1(NOP_EXPR, rettype, ret); + } + + if (this->results_ != NULL) + ret = this->set_results(context, ret); + + this->tree_ = ret; + + return ret; +} + +// Set the result variables if this call returns multiple results. + +tree +Call_expression::set_results(Translate_context* context, tree call_tree) +{ + tree stmt_list = NULL_TREE; + + call_tree = save_expr(call_tree); + + if (TREE_CODE(TREE_TYPE(call_tree)) != RECORD_TYPE) + { + go_assert(saw_errors()); + return call_tree; + } + + Location loc = this->location(); + tree field = TYPE_FIELDS(TREE_TYPE(call_tree)); + size_t rc = this->result_count(); + for (size_t i = 0; i < rc; ++i, field = DECL_CHAIN(field)) + { + go_assert(field != NULL_TREE); + + Temporary_statement* temp = this->result(i); + if (temp == NULL) + { + go_assert(saw_errors()); + return error_mark_node; + } + Temporary_reference_expression* ref = + Expression::make_temporary_reference(temp, loc); + ref->set_is_lvalue(); + tree temp_tree = ref->get_tree(context); + if (temp_tree == error_mark_node) + return error_mark_node; + + tree val_tree = build3_loc(loc.gcc_location(), COMPONENT_REF, + TREE_TYPE(field), call_tree, field, NULL_TREE); + tree set_tree = build2_loc(loc.gcc_location(), MODIFY_EXPR, + void_type_node, temp_tree, val_tree); + + append_to_statement_list(set_tree, &stmt_list); + } + go_assert(field == NULL_TREE); + + return save_expr(stmt_list); +} + +// Dump ast representation for a call expressin. + +void +Call_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + this->fn_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << "("; + if (args_ != NULL) + ast_dump_context->dump_expression_list(this->args_); + + ast_dump_context->ostream() << ") "; +} + +// Make a call expression. + +Call_expression* +Expression::make_call(Expression* fn, Expression_list* args, bool is_varargs, + Location location) +{ + return new Call_expression(fn, args, is_varargs, location); +} + +// A single result from a call which returns multiple results. + +class Call_result_expression : public Expression +{ + public: + Call_result_expression(Call_expression* call, unsigned int index) + : Expression(EXPRESSION_CALL_RESULT, call->location()), + call_(call), index_(index) + { } + + protected: + int + do_traverse(Traverse*); + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return new Call_result_expression(this->call_->call_expression(), + this->index_); + } + + bool + do_must_eval_in_order() const + { return true; } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The underlying call expression. + Expression* call_; + // Which result we want. + unsigned int index_; +}; + +// Traverse a call result. + +int +Call_result_expression::do_traverse(Traverse* traverse) +{ + if (traverse->remember_expression(this->call_)) + { + // We have already traversed the call expression. + return TRAVERSE_CONTINUE; + } + return Expression::traverse(&this->call_, traverse); +} + +// Get the type. + +Type* +Call_result_expression::do_type() +{ + if (this->classification() == EXPRESSION_ERROR) + return Type::make_error_type(); + + // THIS->CALL_ can be replaced with a temporary reference due to + // Call_expression::do_must_eval_in_order when there is an error. + Call_expression* ce = this->call_->call_expression(); + if (ce == NULL) + { + this->set_is_error(); + return Type::make_error_type(); + } + Function_type* fntype = ce->get_function_type(); + if (fntype == NULL) + { + if (ce->issue_error()) + { + if (!ce->fn()->type()->is_error()) + this->report_error(_("expected function")); + } + this->set_is_error(); + return Type::make_error_type(); + } + const Typed_identifier_list* results = fntype->results(); + if (results == NULL || results->size() < 2) + { + if (ce->issue_error()) + this->report_error(_("number of results does not match " + "number of values")); + return Type::make_error_type(); + } + Typed_identifier_list::const_iterator pr = results->begin(); + for (unsigned int i = 0; i < this->index_; ++i) + { + if (pr == results->end()) + break; + ++pr; + } + if (pr == results->end()) + { + if (ce->issue_error()) + this->report_error(_("number of results does not match " + "number of values")); + return Type::make_error_type(); + } + return pr->type(); +} + +// Check the type. Just make sure that we trigger the warning in +// do_type. + +void +Call_result_expression::do_check_types(Gogo*) +{ + this->type(); +} + +// Determine the type. We have nothing to do here, but the 0 result +// needs to pass down to the caller. + +void +Call_result_expression::do_determine_type(const Type_context*) +{ + this->call_->determine_type_no_context(); +} + +// Return the tree. We just refer to the temporary set by the call +// expression. We don't do this at lowering time because it makes it +// hard to evaluate the call at the right time. + +tree +Call_result_expression::do_get_tree(Translate_context* context) +{ + Call_expression* ce = this->call_->call_expression(); + if (ce == NULL) + { + go_assert(this->call_->is_error_expression()); + return error_mark_node; + } + Temporary_statement* ts = ce->result(this->index_); + if (ts == NULL) + { + go_assert(saw_errors()); + return error_mark_node; + } + Expression* ref = Expression::make_temporary_reference(ts, this->location()); + return ref->get_tree(context); +} + +// Dump ast representation for a call result expression. + +void +Call_result_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + // FIXME: Wouldn't it be better if the call is assigned to a temporary + // (struct) and the fields are referenced instead. + ast_dump_context->ostream() << this->index_ << "@("; + ast_dump_context->dump_expression(this->call_); + ast_dump_context->ostream() << ")"; +} + +// Make a reference to a single result of a call which returns +// multiple results. + +Expression* +Expression::make_call_result(Call_expression* call, unsigned int index) +{ + return new Call_result_expression(call, index); +} + +// Class Index_expression. + +// Traversal. + +int +Index_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->left_, traverse) == TRAVERSE_EXIT + || Expression::traverse(&this->start_, traverse) == TRAVERSE_EXIT + || (this->end_ != NULL + && Expression::traverse(&this->end_, traverse) == TRAVERSE_EXIT) + || (this->cap_ != NULL + && Expression::traverse(&this->cap_, traverse) == TRAVERSE_EXIT)) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Lower an index expression. This converts the generic index +// expression into an array index, a string index, or a map index. + +Expression* +Index_expression::do_lower(Gogo*, Named_object*, Statement_inserter*, int) +{ + Location location = this->location(); + Expression* left = this->left_; + Expression* start = this->start_; + Expression* end = this->end_; + Expression* cap = this->cap_; + + Type* type = left->type(); + if (type->is_error()) + return Expression::make_error(location); + else if (left->is_type_expression()) + { + error_at(location, "attempt to index type expression"); + return Expression::make_error(location); + } + else if (type->array_type() != NULL) + return Expression::make_array_index(left, start, end, cap, location); + else if (type->points_to() != NULL + && type->points_to()->array_type() != NULL + && !type->points_to()->is_slice_type()) + { + Expression* deref = Expression::make_unary(OPERATOR_MULT, left, + location); + + // For an ordinary index into the array, the pointer will be + // dereferenced. For a slice it will not--the resulting slice + // will simply reuse the pointer, which is incorrect if that + // pointer is nil. + if (end != NULL || cap != NULL) + deref->issue_nil_check(); + + return Expression::make_array_index(deref, start, end, cap, location); + } + else if (type->is_string_type()) + { + if (cap != NULL) + { + error_at(location, "invalid 3-index slice of string"); + return Expression::make_error(location); + } + return Expression::make_string_index(left, start, end, location); + } + else if (type->map_type() != NULL) + { + if (end != NULL || cap != NULL) + { + error_at(location, "invalid slice of map"); + return Expression::make_error(location); + } + Map_index_expression* ret = Expression::make_map_index(left, start, + location); + if (this->is_lvalue_) + ret->set_is_lvalue(); + return ret; + } + else + { + error_at(location, + "attempt to index object which is not array, string, or map"); + return Expression::make_error(location); + } +} + +// Write an indexed expression +// (expr[expr:expr:expr], expr[expr:expr] or expr[expr]) to a dump context. + +void +Index_expression::dump_index_expression(Ast_dump_context* ast_dump_context, + const Expression* expr, + const Expression* start, + const Expression* end, + const Expression* cap) +{ + expr->dump_expression(ast_dump_context); + ast_dump_context->ostream() << "["; + start->dump_expression(ast_dump_context); + if (end != NULL) + { + ast_dump_context->ostream() << ":"; + end->dump_expression(ast_dump_context); + } + if (cap != NULL) + { + ast_dump_context->ostream() << ":"; + cap->dump_expression(ast_dump_context); + } + ast_dump_context->ostream() << "]"; +} + +// Dump ast representation for an index expression. + +void +Index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + Index_expression::dump_index_expression(ast_dump_context, this->left_, + this->start_, this->end_, this->cap_); +} + +// Make an index expression. + +Expression* +Expression::make_index(Expression* left, Expression* start, Expression* end, + Expression* cap, Location location) +{ + return new Index_expression(left, start, end, cap, location); +} + +// An array index. This is used for both indexing and slicing. + +class Array_index_expression : public Expression +{ + public: + Array_index_expression(Expression* array, Expression* start, + Expression* end, Expression* cap, Location location) + : Expression(EXPRESSION_ARRAY_INDEX, location), + array_(array), start_(start), end_(end), cap_(cap), type_(NULL) + { } + + protected: + int + do_traverse(Traverse*); + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_flatten(Gogo*, Named_object*, Statement_inserter*); + + Expression* + do_copy() + { + return Expression::make_array_index(this->array_->copy(), + this->start_->copy(), + (this->end_ == NULL + ? NULL + : this->end_->copy()), + (this->cap_ == NULL + ? NULL + : this->cap_->copy()), + this->location()); + } + + bool + do_must_eval_subexpressions_in_order(int* skip) const + { + *skip = 1; + return true; + } + + bool + do_is_addressable() const; + + void + do_address_taken(bool escapes) + { this->array_->address_taken(escapes); } + + void + do_issue_nil_check() + { this->array_->issue_nil_check(); } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The array we are getting a value from. + Expression* array_; + // The start or only index. + Expression* start_; + // The end index of a slice. This may be NULL for a simple array + // index, or it may be a nil expression for the length of the array. + Expression* end_; + // The capacity argument of a slice. This may be NULL for an array index or + // slice. + Expression* cap_; + // The type of the expression. + Type* type_; +}; + +// Array index traversal. + +int +Array_index_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->array_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (Expression::traverse(&this->start_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->end_ != NULL) + { + if (Expression::traverse(&this->end_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + if (this->cap_ != NULL) + { + if (Expression::traverse(&this->cap_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Return the type of an array index. + +Type* +Array_index_expression::do_type() +{ + if (this->type_ == NULL) + { + Array_type* type = this->array_->type()->array_type(); + if (type == NULL) + this->type_ = Type::make_error_type(); + else if (this->end_ == NULL) + this->type_ = type->element_type(); + else if (type->is_slice_type()) + { + // A slice of a slice has the same type as the original + // slice. + this->type_ = this->array_->type()->deref(); + } + else + { + // A slice of an array is a slice. + this->type_ = Type::make_array_type(type->element_type(), NULL); + } + } + return this->type_; +} + +// Set the type of an array index. + +void +Array_index_expression::do_determine_type(const Type_context*) +{ + this->array_->determine_type_no_context(); + this->start_->determine_type_no_context(); + if (this->end_ != NULL) + this->end_->determine_type_no_context(); + if (this->cap_ != NULL) + this->cap_->determine_type_no_context(); +} + +// Check types of an array index. + +void +Array_index_expression::do_check_types(Gogo*) +{ + Numeric_constant nc; + unsigned long v; + if (this->start_->type()->integer_type() == NULL + && !this->start_->type()->is_error() + && (!this->start_->numeric_constant_value(&nc) + || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) + this->report_error(_("index must be integer")); + if (this->end_ != NULL + && this->end_->type()->integer_type() == NULL + && !this->end_->type()->is_error() + && !this->end_->is_nil_expression() + && !this->end_->is_error_expression() + && (!this->end_->numeric_constant_value(&nc) + || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) + this->report_error(_("slice end must be integer")); + if (this->cap_ != NULL + && this->cap_->type()->integer_type() == NULL + && !this->cap_->type()->is_error() + && !this->cap_->is_nil_expression() + && !this->cap_->is_error_expression() + && (!this->cap_->numeric_constant_value(&nc) + || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) + this->report_error(_("slice capacity must be integer")); + + Array_type* array_type = this->array_->type()->array_type(); + if (array_type == NULL) + { + go_assert(this->array_->type()->is_error()); + return; + } + + unsigned int int_bits = + Type::lookup_integer_type("int")->integer_type()->bits(); + + Numeric_constant lvalnc; + mpz_t lval; + bool lval_valid = (array_type->length() != NULL + && array_type->length()->numeric_constant_value(&lvalnc) + && lvalnc.to_int(&lval)); + Numeric_constant inc; + mpz_t ival; + bool ival_valid = false; + if (this->start_->numeric_constant_value(&inc) && inc.to_int(&ival)) + { + ival_valid = true; + if (mpz_sgn(ival) < 0 + || mpz_sizeinbase(ival, 2) >= int_bits + || (lval_valid + && (this->end_ == NULL + ? mpz_cmp(ival, lval) >= 0 + : mpz_cmp(ival, lval) > 0))) + { + error_at(this->start_->location(), "array index out of bounds"); + this->set_is_error(); + } + } + if (this->end_ != NULL && !this->end_->is_nil_expression()) + { + Numeric_constant enc; + mpz_t eval; + bool eval_valid = false; + if (this->end_->numeric_constant_value(&enc) && enc.to_int(&eval)) + { + eval_valid = true; + if (mpz_sgn(eval) < 0 + || mpz_sizeinbase(eval, 2) >= int_bits + || (lval_valid && mpz_cmp(eval, lval) > 0)) + { + error_at(this->end_->location(), "array index out of bounds"); + this->set_is_error(); + } + else if (ival_valid && mpz_cmp(ival, eval) > 0) + this->report_error(_("inverted slice range")); + } + + Numeric_constant cnc; + mpz_t cval; + if (this->cap_ != NULL + && this->cap_->numeric_constant_value(&cnc) && cnc.to_int(&cval)) + { + if (mpz_sgn(cval) < 0 + || mpz_sizeinbase(cval, 2) >= int_bits + || (lval_valid && mpz_cmp(cval, lval) > 0)) + { + error_at(this->cap_->location(), "array index out of bounds"); + this->set_is_error(); + } + else if (ival_valid && mpz_cmp(ival, cval) > 0) + { + error_at(this->cap_->location(), + "invalid slice index: capacity less than start"); + this->set_is_error(); + } + else if (eval_valid && mpz_cmp(eval, cval) > 0) + { + error_at(this->cap_->location(), + "invalid slice index: capacity less than length"); + this->set_is_error(); + } + mpz_clear(cval); + } + + if (eval_valid) + mpz_clear(eval); + } + if (ival_valid) + mpz_clear(ival); + if (lval_valid) + mpz_clear(lval); + + // A slice of an array requires an addressable array. A slice of a + // slice is always possible. + if (this->end_ != NULL && !array_type->is_slice_type()) + { + if (!this->array_->is_addressable()) + this->report_error(_("slice of unaddressable value")); + else + this->array_->address_taken(true); + } +} + +// Flatten array indexing by using a temporary variable for slices. + +Expression* +Array_index_expression::do_flatten(Gogo*, Named_object*, + Statement_inserter* inserter) +{ + Location loc = this->location(); + if (this->array_->type()->is_slice_type() && !this->array_->is_variable()) + { + Temporary_statement* temp = Statement::make_temporary(NULL, this->array_, loc); + inserter->insert(temp); + this->array_ = Expression::make_temporary_reference(temp, loc); + } + return this; +} + +// Return whether this expression is addressable. + +bool +Array_index_expression::do_is_addressable() const +{ + // A slice expression is not addressable. + if (this->end_ != NULL) + return false; + + // An index into a slice is addressable. + if (this->array_->type()->is_slice_type()) + return true; + + // An index into an array is addressable if the array is + // addressable. + return this->array_->is_addressable(); +} + +// Get a tree for an array index. + +tree +Array_index_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Location loc = this->location(); + + Array_type* array_type = this->array_->type()->array_type(); + if (array_type == NULL) + { + go_assert(this->array_->type()->is_error()); + return error_mark_node; + } + go_assert(!array_type->is_slice_type() || this->array_->is_variable()); + + tree type_tree = type_to_tree(array_type->get_backend(gogo)); + if (type_tree == error_mark_node) + return error_mark_node; + + tree length_tree = NULL_TREE; + if (this->end_ == NULL || this->end_->is_nil_expression()) + { + Expression* len = array_type->get_length(gogo, this->array_); + length_tree = len->get_tree(context); + if (length_tree == error_mark_node) + return error_mark_node; + length_tree = save_expr(length_tree); + } + + tree capacity_tree = NULL_TREE; + if (this->end_ != NULL) + { + Expression* cap = array_type->get_capacity(gogo, this->array_); + capacity_tree = cap->get_tree(context); + if (capacity_tree == error_mark_node) + return error_mark_node; + capacity_tree = save_expr(capacity_tree); + } + + tree cap_arg = capacity_tree; + if (this->cap_ != NULL) + { + cap_arg = this->cap_->get_tree(context); + if (cap_arg == error_mark_node) + return error_mark_node; + } + + tree length_type = (length_tree != NULL_TREE + ? TREE_TYPE(length_tree) + : TREE_TYPE(cap_arg)); + + tree bad_index = boolean_false_node; + + tree start_tree = this->start_->get_tree(context); + if (start_tree == error_mark_node) + return error_mark_node; + if (!DECL_P(start_tree)) + start_tree = save_expr(start_tree); + if (!INTEGRAL_TYPE_P(TREE_TYPE(start_tree))) + start_tree = convert_to_integer(length_type, start_tree); + + bad_index = Expression::check_bounds(start_tree, length_type, bad_index, + loc); + + start_tree = fold_convert_loc(loc.gcc_location(), length_type, start_tree); + bad_index = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, bad_index, + fold_build2_loc(loc.gcc_location(), + (this->end_ == NULL + ? GE_EXPR + : GT_EXPR), + boolean_type_node, start_tree, + (this->end_ == NULL + ? length_tree + : capacity_tree))); + + int code = (array_type->length() != NULL + ? (this->end_ == NULL + ? RUNTIME_ERROR_ARRAY_INDEX_OUT_OF_BOUNDS + : RUNTIME_ERROR_ARRAY_SLICE_OUT_OF_BOUNDS) + : (this->end_ == NULL + ? RUNTIME_ERROR_SLICE_INDEX_OUT_OF_BOUNDS + : RUNTIME_ERROR_SLICE_SLICE_OUT_OF_BOUNDS)); + tree crash = gogo->runtime_error(code, loc)->get_tree(context); + + if (this->end_ == NULL) + { + // Simple array indexing. This has to return an l-value, so + // wrap the index check into START_TREE. + start_tree = build2(COMPOUND_EXPR, TREE_TYPE(start_tree), + build3(COND_EXPR, void_type_node, + bad_index, crash, NULL_TREE), + start_tree); + start_tree = fold_convert_loc(loc.gcc_location(), sizetype, start_tree); + + if (array_type->length() != NULL) + { + // Fixed array. + tree array_tree = this->array_->get_tree(context); + if (array_tree == error_mark_node) + return error_mark_node; + return build4(ARRAY_REF, TREE_TYPE(type_tree), array_tree, + start_tree, NULL_TREE, NULL_TREE); + } + else + { + // Open array. + Expression* valptr = + array_type->get_value_pointer(gogo, this->array_); + tree values = valptr->get_tree(context); + Type* element_type = array_type->element_type(); + Btype* belement_type = element_type->get_backend(gogo); + tree element_type_tree = type_to_tree(belement_type); + if (element_type_tree == error_mark_node) + return error_mark_node; + tree element_size = TYPE_SIZE_UNIT(element_type_tree); + tree offset = fold_build2_loc(loc.gcc_location(), MULT_EXPR, sizetype, + start_tree, element_size); + tree ptr = fold_build2_loc(loc.gcc_location(), POINTER_PLUS_EXPR, + TREE_TYPE(values), values, offset); + return build_fold_indirect_ref(ptr); + } + } + + // Array slice. + + if (this->cap_ != NULL) + { + if (!DECL_P(cap_arg)) + cap_arg = save_expr(cap_arg); + if (!INTEGRAL_TYPE_P(TREE_TYPE(cap_arg))) + cap_arg = convert_to_integer(length_type, cap_arg); + + bad_index = Expression::check_bounds(cap_arg, length_type, bad_index, + loc); + cap_arg = fold_convert_loc(loc.gcc_location(), length_type, cap_arg); + + tree bad_cap = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, + fold_build2_loc(loc.gcc_location(), + LT_EXPR, boolean_type_node, + cap_arg, start_tree), + fold_build2_loc(loc.gcc_location(), + GT_EXPR, boolean_type_node, + cap_arg, capacity_tree)); + bad_index = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, bad_index, bad_cap); + } + + tree end_tree; + if (this->end_->is_nil_expression()) + end_tree = length_tree; + else + { + end_tree = this->end_->get_tree(context); + if (end_tree == error_mark_node) + return error_mark_node; + if (!DECL_P(end_tree)) + end_tree = save_expr(end_tree); + if (!INTEGRAL_TYPE_P(TREE_TYPE(end_tree))) + end_tree = convert_to_integer(length_type, end_tree); + + bad_index = Expression::check_bounds(end_tree, length_type, bad_index, + loc); + + end_tree = fold_convert_loc(loc.gcc_location(), length_type, end_tree); + + tree bad_end = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, + fold_build2_loc(loc.gcc_location(), + LT_EXPR, boolean_type_node, + end_tree, start_tree), + fold_build2_loc(loc.gcc_location(), + GT_EXPR, boolean_type_node, + end_tree, cap_arg)); + bad_index = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, bad_index, bad_end); + } + + + Type* element_type = array_type->element_type(); + tree element_type_tree = type_to_tree(element_type->get_backend(gogo)); + if (element_type_tree == error_mark_node) + return error_mark_node; + tree element_size = TYPE_SIZE_UNIT(element_type_tree); + + tree offset = fold_build2_loc(loc.gcc_location(), MULT_EXPR, sizetype, + fold_convert_loc(loc.gcc_location(), sizetype, + start_tree), + element_size); + + Expression* valptr = array_type->get_value_pointer(gogo, this->array_); + tree value_pointer = valptr->get_tree(context); + if (value_pointer == error_mark_node) + return error_mark_node; + + value_pointer = fold_build2_loc(loc.gcc_location(), POINTER_PLUS_EXPR, + TREE_TYPE(value_pointer), + value_pointer, offset); + + tree result_length_tree = fold_build2_loc(loc.gcc_location(), MINUS_EXPR, + length_type, end_tree, start_tree); + + tree result_capacity_tree = fold_build2_loc(loc.gcc_location(), MINUS_EXPR, + length_type, cap_arg, start_tree); + + tree struct_tree = type_to_tree(this->type()->get_backend(gogo)); + go_assert(TREE_CODE(struct_tree) == RECORD_TYPE); + + vec<constructor_elt, va_gc> *init; + vec_alloc (init, 3); + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = init->quick_push(empty); + tree field = TYPE_FIELDS(struct_tree); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__values") == 0); + elt->index = field; + elt->value = value_pointer; + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__count") == 0); + elt->index = field; + elt->value = fold_convert_loc(loc.gcc_location(), TREE_TYPE(field), + result_length_tree); + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__capacity") == 0); + elt->index = field; + elt->value = fold_convert_loc(loc.gcc_location(), TREE_TYPE(field), + result_capacity_tree); + + tree constructor = build_constructor(struct_tree, init); + + if (TREE_CONSTANT(value_pointer) + && TREE_CONSTANT(result_length_tree) + && TREE_CONSTANT(result_capacity_tree)) + TREE_CONSTANT(constructor) = 1; + + return fold_build2_loc(loc.gcc_location(), COMPOUND_EXPR, + TREE_TYPE(constructor), + build3(COND_EXPR, void_type_node, + bad_index, crash, NULL_TREE), + constructor); +} + +// Dump ast representation for an array index expression. + +void +Array_index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + Index_expression::dump_index_expression(ast_dump_context, this->array_, + this->start_, this->end_, this->cap_); +} + +// Make an array index expression. END and CAP may be NULL. + +Expression* +Expression::make_array_index(Expression* array, Expression* start, + Expression* end, Expression* cap, + Location location) +{ + return new Array_index_expression(array, start, end, cap, location); +} + +// A string index. This is used for both indexing and slicing. + +class String_index_expression : public Expression +{ + public: + String_index_expression(Expression* string, Expression* start, + Expression* end, Location location) + : Expression(EXPRESSION_STRING_INDEX, location), + string_(string), start_(start), end_(end) + { } + + protected: + int + do_traverse(Traverse*); + + Type* + do_type(); + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return Expression::make_string_index(this->string_->copy(), + this->start_->copy(), + (this->end_ == NULL + ? NULL + : this->end_->copy()), + this->location()); + } + + bool + do_must_eval_subexpressions_in_order(int* skip) const + { + *skip = 1; + return true; + } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The string we are getting a value from. + Expression* string_; + // The start or only index. + Expression* start_; + // The end index of a slice. This may be NULL for a single index, + // or it may be a nil expression for the length of the string. + Expression* end_; +}; + +// String index traversal. + +int +String_index_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->string_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (Expression::traverse(&this->start_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (this->end_ != NULL) + { + if (Expression::traverse(&this->end_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + return TRAVERSE_CONTINUE; +} + +// Return the type of a string index. + +Type* +String_index_expression::do_type() +{ + if (this->end_ == NULL) + return Type::lookup_integer_type("uint8"); + else + return this->string_->type(); +} + +// Determine the type of a string index. + +void +String_index_expression::do_determine_type(const Type_context*) +{ + this->string_->determine_type_no_context(); + this->start_->determine_type_no_context(); + if (this->end_ != NULL) + this->end_->determine_type_no_context(); +} + +// Check types of a string index. + +void +String_index_expression::do_check_types(Gogo*) +{ + Numeric_constant nc; + unsigned long v; + if (this->start_->type()->integer_type() == NULL + && !this->start_->type()->is_error() + && (!this->start_->numeric_constant_value(&nc) + || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) + this->report_error(_("index must be integer")); + if (this->end_ != NULL + && this->end_->type()->integer_type() == NULL + && !this->end_->type()->is_error() + && !this->end_->is_nil_expression() + && !this->end_->is_error_expression() + && (!this->end_->numeric_constant_value(&nc) + || nc.to_unsigned_long(&v) == Numeric_constant::NC_UL_NOTINT)) + this->report_error(_("slice end must be integer")); + + std::string sval; + bool sval_valid = this->string_->string_constant_value(&sval); + + Numeric_constant inc; + mpz_t ival; + bool ival_valid = false; + if (this->start_->numeric_constant_value(&inc) && inc.to_int(&ival)) + { + ival_valid = true; + if (mpz_sgn(ival) < 0 + || (sval_valid && mpz_cmp_ui(ival, sval.length()) >= 0)) + { + error_at(this->start_->location(), "string index out of bounds"); + this->set_is_error(); + } + } + if (this->end_ != NULL && !this->end_->is_nil_expression()) + { + Numeric_constant enc; + mpz_t eval; + if (this->end_->numeric_constant_value(&enc) && enc.to_int(&eval)) + { + if (mpz_sgn(eval) < 0 + || (sval_valid && mpz_cmp_ui(eval, sval.length()) > 0)) + { + error_at(this->end_->location(), "string index out of bounds"); + this->set_is_error(); + } + else if (ival_valid && mpz_cmp(ival, eval) > 0) + this->report_error(_("inverted slice range")); + mpz_clear(eval); + } + } + if (ival_valid) + mpz_clear(ival); +} + +// Get a tree for a string index. + +tree +String_index_expression::do_get_tree(Translate_context* context) +{ + Location loc = this->location(); + + tree string_tree = this->string_->get_tree(context); + if (string_tree == error_mark_node) + return error_mark_node; + + if (this->string_->type()->points_to() != NULL) + string_tree = build_fold_indirect_ref(string_tree); + if (!DECL_P(string_tree)) + string_tree = save_expr(string_tree); + tree string_type = TREE_TYPE(string_tree); + + tree length_tree = String_type::length_tree(context->gogo(), string_tree); + length_tree = save_expr(length_tree); + + Type* int_type = Type::lookup_integer_type("int"); + tree length_type = type_to_tree(int_type->get_backend(context->gogo())); + + tree bad_index = boolean_false_node; + + tree start_tree = this->start_->get_tree(context); + if (start_tree == error_mark_node) + return error_mark_node; + if (!DECL_P(start_tree)) + start_tree = save_expr(start_tree); + if (!INTEGRAL_TYPE_P(TREE_TYPE(start_tree))) + start_tree = convert_to_integer(length_type, start_tree); + + bad_index = Expression::check_bounds(start_tree, length_type, bad_index, + loc); + + start_tree = fold_convert_loc(loc.gcc_location(), length_type, start_tree); + + int code = (this->end_ == NULL + ? RUNTIME_ERROR_STRING_INDEX_OUT_OF_BOUNDS + : RUNTIME_ERROR_STRING_SLICE_OUT_OF_BOUNDS); + tree crash = context->gogo()->runtime_error(code, loc)->get_tree(context); + + if (this->end_ == NULL) + { + bad_index = fold_build2_loc(loc.gcc_location(), TRUTH_OR_EXPR, + boolean_type_node, bad_index, + fold_build2_loc(loc.gcc_location(), GE_EXPR, + boolean_type_node, + start_tree, length_tree)); + + tree bytes_tree = String_type::bytes_tree(context->gogo(), string_tree); + tree ptr = fold_build2_loc(loc.gcc_location(), POINTER_PLUS_EXPR, + TREE_TYPE(bytes_tree), + bytes_tree, + fold_convert_loc(loc.gcc_location(), sizetype, + start_tree)); + tree index = build_fold_indirect_ref_loc(loc.gcc_location(), ptr); + + return build2(COMPOUND_EXPR, TREE_TYPE(index), + build3(COND_EXPR, void_type_node, + bad_index, crash, NULL_TREE), + index); + } + else + { + tree end_tree; + if (this->end_->is_nil_expression()) + end_tree = build_int_cst(length_type, -1); + else + { + end_tree = this->end_->get_tree(context); + if (end_tree == error_mark_node) + return error_mark_node; + if (!DECL_P(end_tree)) + end_tree = save_expr(end_tree); + if (!INTEGRAL_TYPE_P(TREE_TYPE(end_tree))) + end_tree = convert_to_integer(length_type, end_tree); + + bad_index = Expression::check_bounds(end_tree, length_type, + bad_index, loc); + + end_tree = fold_convert_loc(loc.gcc_location(), length_type, + end_tree); + } + + static tree strslice_fndecl; + tree ret = Gogo::call_builtin(&strslice_fndecl, + loc, + "__go_string_slice", + 3, + string_type, + string_type, + string_tree, + length_type, + start_tree, + length_type, + end_tree); + if (ret == error_mark_node) + return error_mark_node; + // This will panic if the bounds are out of range for the + // string. + TREE_NOTHROW(strslice_fndecl) = 0; + + if (bad_index == boolean_false_node) + return ret; + else + return build2(COMPOUND_EXPR, TREE_TYPE(ret), + build3(COND_EXPR, void_type_node, + bad_index, crash, NULL_TREE), + ret); + } +} + +// Dump ast representation for a string index expression. + +void +String_index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + Index_expression::dump_index_expression(ast_dump_context, this->string_, + this->start_, this->end_, NULL); +} + +// Make a string index expression. END may be NULL. + +Expression* +Expression::make_string_index(Expression* string, Expression* start, + Expression* end, Location location) +{ + return new String_index_expression(string, start, end, location); +} + +// Class Map_index. + +// Get the type of the map. + +Map_type* +Map_index_expression::get_map_type() const +{ + Map_type* mt = this->map_->type()->deref()->map_type(); + if (mt == NULL) + go_assert(saw_errors()); + return mt; +} + +// Map index traversal. + +int +Map_index_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->map_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return Expression::traverse(&this->index_, traverse); +} + +// Return the type of a map index. + +Type* +Map_index_expression::do_type() +{ + Map_type* mt = this->get_map_type(); + if (mt == NULL) + return Type::make_error_type(); + Type* type = mt->val_type(); + // If this map index is in a tuple assignment, we actually return a + // pointer to the value type. Tuple_map_assignment_statement is + // responsible for handling this correctly. We need to get the type + // right in case this gets assigned to a temporary variable. + if (this->is_in_tuple_assignment_) + type = Type::make_pointer_type(type); + return type; +} + +// Fix the type of a map index. + +void +Map_index_expression::do_determine_type(const Type_context*) +{ + this->map_->determine_type_no_context(); + Map_type* mt = this->get_map_type(); + Type* key_type = mt == NULL ? NULL : mt->key_type(); + Type_context subcontext(key_type, false); + this->index_->determine_type(&subcontext); +} + +// Check types of a map index. + +void +Map_index_expression::do_check_types(Gogo*) +{ + std::string reason; + Map_type* mt = this->get_map_type(); + if (mt == NULL) + return; + if (!Type::are_assignable(mt->key_type(), this->index_->type(), &reason)) + { + if (reason.empty()) + this->report_error(_("incompatible type for map index")); + else + { + error_at(this->location(), "incompatible type for map index (%s)", + reason.c_str()); + this->set_is_error(); + } + } +} + +// Get a tree for a map index. + +tree +Map_index_expression::do_get_tree(Translate_context* context) +{ + Map_type* type = this->get_map_type(); + if (type == NULL) + return error_mark_node; + + tree valptr = this->get_value_pointer(context, this->is_lvalue_); + if (valptr == error_mark_node) + return error_mark_node; + valptr = save_expr(valptr); + + tree val_type_tree = TREE_TYPE(TREE_TYPE(valptr)); + + if (this->is_lvalue_) + return build_fold_indirect_ref(valptr); + else if (this->is_in_tuple_assignment_) + { + // Tuple_map_assignment_statement is responsible for using this + // appropriately. + return valptr; + } + else + { + Gogo* gogo = context->gogo(); + Btype* val_btype = type->val_type()->get_backend(gogo); + Bexpression* val_zero = gogo->backend()->zero_expression(val_btype); + return fold_build3(COND_EXPR, val_type_tree, + fold_build2(EQ_EXPR, boolean_type_node, valptr, + fold_convert(TREE_TYPE(valptr), + null_pointer_node)), + expr_to_tree(val_zero), + build_fold_indirect_ref(valptr)); + } +} + +// Get a tree for the map index. This returns a tree which evaluates +// to a pointer to a value. The pointer will be NULL if the key is +// not in the map. + +tree +Map_index_expression::get_value_pointer(Translate_context* context, + bool insert) +{ + Map_type* type = this->get_map_type(); + if (type == NULL) + return error_mark_node; + + tree map_tree = this->map_->get_tree(context); + tree index_tree = this->index_->get_tree(context); + index_tree = Expression::convert_for_assignment(context, type->key_type(), + this->index_->type(), + index_tree, + this->location()); + if (map_tree == error_mark_node || index_tree == error_mark_node) + return error_mark_node; + + if (this->map_->type()->points_to() != NULL) + map_tree = build_fold_indirect_ref(map_tree); + + // We need to pass in a pointer to the key, so stuff it into a + // variable. + tree tmp; + tree make_tmp; + if (current_function_decl != NULL) + { + tmp = create_tmp_var(TREE_TYPE(index_tree), get_name(index_tree)); + DECL_IGNORED_P(tmp) = 0; + DECL_INITIAL(tmp) = index_tree; + make_tmp = build1(DECL_EXPR, void_type_node, tmp); + TREE_ADDRESSABLE(tmp) = 1; + } + else + { + tmp = build_decl(this->location().gcc_location(), VAR_DECL, + create_tmp_var_name("M"), + TREE_TYPE(index_tree)); + DECL_EXTERNAL(tmp) = 0; + TREE_PUBLIC(tmp) = 0; + TREE_STATIC(tmp) = 1; + DECL_ARTIFICIAL(tmp) = 1; + if (!TREE_CONSTANT(index_tree)) + make_tmp = fold_build2_loc(this->location().gcc_location(), + INIT_EXPR, void_type_node, + tmp, index_tree); + else + { + TREE_READONLY(tmp) = 1; + TREE_CONSTANT(tmp) = 1; + DECL_INITIAL(tmp) = index_tree; + make_tmp = NULL_TREE; + } + rest_of_decl_compilation(tmp, 1, 0); + } + tree tmpref = + fold_convert_loc(this->location().gcc_location(), const_ptr_type_node, + build_fold_addr_expr_loc(this->location().gcc_location(), + tmp)); + + static tree map_index_fndecl; + tree call = Gogo::call_builtin(&map_index_fndecl, + this->location(), + "__go_map_index", + 3, + const_ptr_type_node, + TREE_TYPE(map_tree), + map_tree, + const_ptr_type_node, + tmpref, + boolean_type_node, + (insert + ? boolean_true_node + : boolean_false_node)); + if (call == error_mark_node) + return error_mark_node; + // This can panic on a map of interface type if the interface holds + // an uncomparable or unhashable type. + TREE_NOTHROW(map_index_fndecl) = 0; + + Type* val_type = type->val_type(); + tree val_type_tree = type_to_tree(val_type->get_backend(context->gogo())); + if (val_type_tree == error_mark_node) + return error_mark_node; + tree ptr_val_type_tree = build_pointer_type(val_type_tree); + + tree ret = fold_convert_loc(this->location().gcc_location(), + ptr_val_type_tree, call); + if (make_tmp != NULL_TREE) + ret = build2(COMPOUND_EXPR, ptr_val_type_tree, make_tmp, ret); + return ret; +} + +// Dump ast representation for a map index expression + +void +Map_index_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + Index_expression::dump_index_expression(ast_dump_context, this->map_, + this->index_, NULL, NULL); +} + +// Make a map index expression. + +Map_index_expression* +Expression::make_map_index(Expression* map, Expression* index, + Location location) +{ + return new Map_index_expression(map, index, location); +} + +// Class Field_reference_expression. + +// Lower a field reference expression. There is nothing to lower, but +// this is where we generate the tracking information for fields with +// the magic go:"track" tag. + +Expression* +Field_reference_expression::do_lower(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, int) +{ + Struct_type* struct_type = this->expr_->type()->struct_type(); + if (struct_type == NULL) + { + // Error will be reported elsewhere. + return this; + } + const Struct_field* field = struct_type->field(this->field_index_); + if (field == NULL) + return this; + if (!field->has_tag()) + return this; + if (field->tag().find("go:\"track\"") == std::string::npos) + return this; + + // We have found a reference to a tracked field. Build a call to + // the runtime function __go_fieldtrack with a string that describes + // the field. FIXME: We should only call this once per referenced + // field per function, not once for each reference to the field. + + if (this->called_fieldtrack_) + return this; + this->called_fieldtrack_ = true; + + Location loc = this->location(); + + std::string s = "fieldtrack \""; + Named_type* nt = this->expr_->type()->named_type(); + if (nt == NULL || nt->named_object()->package() == NULL) + s.append(gogo->pkgpath()); + else + s.append(nt->named_object()->package()->pkgpath()); + s.push_back('.'); + if (nt != NULL) + s.append(Gogo::unpack_hidden_name(nt->name())); + s.push_back('.'); + s.append(field->field_name()); + s.push_back('"'); + + // We can't use a string here, because internally a string holds a + // pointer to the actual bytes; when the linker garbage collects the + // string, it won't garbage collect the bytes. So we use a + // [...]byte. + + mpz_t val; + mpz_init_set_ui(val, s.length()); + Expression* length_expr = Expression::make_integer(&val, NULL, loc); + mpz_clear(val); + + Type* byte_type = gogo->lookup_global("byte")->type_value(); + Type* array_type = Type::make_array_type(byte_type, length_expr); + + Expression_list* bytes = new Expression_list(); + for (std::string::const_iterator p = s.begin(); p != s.end(); p++) + { + mpz_init_set_ui(val, *p); + Expression* byte = Expression::make_integer(&val, NULL, loc); + mpz_clear(val); + bytes->push_back(byte); + } + + Expression* e = Expression::make_composite_literal(array_type, 0, false, + bytes, false, loc); + + Variable* var = new Variable(array_type, e, true, false, false, loc); + + static int count; + char buf[50]; + snprintf(buf, sizeof buf, "fieldtrack.%d", count); + ++count; + + Named_object* no = gogo->add_variable(buf, var); + e = Expression::make_var_reference(no, loc); + e = Expression::make_unary(OPERATOR_AND, e, loc); + + Expression* call = Runtime::make_call(Runtime::FIELDTRACK, loc, 1, e); + inserter->insert(Statement::make_statement(call, false)); + + // Put this function, and the global variable we just created, into + // unique sections. This will permit the linker to garbage collect + // them if they are not referenced. The effect is that the only + // strings, indicating field references, that will wind up in the + // executable will be those for functions that are actually needed. + if (function != NULL) + function->func_value()->set_in_unique_section(); + var->set_in_unique_section(); + + return this; +} + +// Return the type of a field reference. + +Type* +Field_reference_expression::do_type() +{ + Type* type = this->expr_->type(); + if (type->is_error()) + return type; + Struct_type* struct_type = type->struct_type(); + go_assert(struct_type != NULL); + return struct_type->field(this->field_index_)->type(); +} + +// Check the types for a field reference. + +void +Field_reference_expression::do_check_types(Gogo*) +{ + Type* type = this->expr_->type(); + if (type->is_error()) + return; + Struct_type* struct_type = type->struct_type(); + go_assert(struct_type != NULL); + go_assert(struct_type->field(this->field_index_) != NULL); +} + +// Get a tree for a field reference. + +tree +Field_reference_expression::do_get_tree(Translate_context* context) +{ + Bexpression* bstruct = tree_to_expr(this->expr_->get_tree(context)); + Bexpression* ret = + context->gogo()->backend()->struct_field_expression(bstruct, + this->field_index_, + this->location()); + return expr_to_tree(ret); +} + +// Dump ast representation for a field reference expression. + +void +Field_reference_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + this->expr_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << "." << this->field_index_; +} + +// Make a reference to a qualified identifier in an expression. + +Field_reference_expression* +Expression::make_field_reference(Expression* expr, unsigned int field_index, + Location location) +{ + return new Field_reference_expression(expr, field_index, location); +} + +// Class Interface_field_reference_expression. + +// Return an expression for the pointer to the function to call. + +Expression* +Interface_field_reference_expression::get_function() +{ + Expression* ref = this->expr_; + Location loc = this->location(); + if (ref->type()->points_to() != NULL) + ref = Expression::make_unary(OPERATOR_MULT, ref, loc); + + Expression* mtable = + Expression::make_interface_info(ref, INTERFACE_INFO_METHODS, loc); + Struct_type* mtable_type = mtable->type()->points_to()->struct_type(); + + std::string name = Gogo::unpack_hidden_name(this->name_); + unsigned int index; + const Struct_field* field = mtable_type->find_local_field(name, &index); + go_assert(field != NULL); + mtable = Expression::make_unary(OPERATOR_MULT, mtable, loc); + return Expression::make_field_reference(mtable, index, loc); +} + +// Return an expression for the first argument to pass to the interface +// function. + +Expression* +Interface_field_reference_expression::get_underlying_object() +{ + Expression* expr = this->expr_; + if (expr->type()->points_to() != NULL) + expr = Expression::make_unary(OPERATOR_MULT, expr, this->location()); + return Expression::make_interface_info(expr, INTERFACE_INFO_OBJECT, + this->location()); +} + +// Traversal. + +int +Interface_field_reference_expression::do_traverse(Traverse* traverse) +{ + return Expression::traverse(&this->expr_, traverse); +} + +// Lower the expression. If this expression is not called, we need to +// evaluate the expression twice when converting to the backend +// interface. So introduce a temporary variable if necessary. + +Expression* +Interface_field_reference_expression::do_lower(Gogo*, Named_object*, + Statement_inserter* inserter, + int) +{ + if (!this->expr_->is_variable()) + { + Temporary_statement* temp = + Statement::make_temporary(this->expr_->type(), NULL, this->location()); + inserter->insert(temp); + this->expr_ = Expression::make_set_and_use_temporary(temp, this->expr_, + this->location()); + } + return this; +} + +// Return the type of an interface field reference. + +Type* +Interface_field_reference_expression::do_type() +{ + Type* expr_type = this->expr_->type(); + + Type* points_to = expr_type->points_to(); + if (points_to != NULL) + expr_type = points_to; + + Interface_type* interface_type = expr_type->interface_type(); + if (interface_type == NULL) + return Type::make_error_type(); + + const Typed_identifier* method = interface_type->find_method(this->name_); + if (method == NULL) + return Type::make_error_type(); + + return method->type(); +} + +// Determine types. + +void +Interface_field_reference_expression::do_determine_type(const Type_context*) +{ + this->expr_->determine_type_no_context(); +} + +// Check the types for an interface field reference. + +void +Interface_field_reference_expression::do_check_types(Gogo*) +{ + Type* type = this->expr_->type(); + + Type* points_to = type->points_to(); + if (points_to != NULL) + type = points_to; + + Interface_type* interface_type = type->interface_type(); + if (interface_type == NULL) + { + if (!type->is_error_type()) + this->report_error(_("expected interface or pointer to interface")); + } + else + { + const Typed_identifier* method = + interface_type->find_method(this->name_); + if (method == NULL) + { + error_at(this->location(), "method %qs not in interface", + Gogo::message_name(this->name_).c_str()); + this->set_is_error(); + } + } +} + +// If an interface field reference is not simply called, then it is +// represented as a closure. The closure will hold a single variable, +// the value of the interface on which the method should be called. +// The function will be a simple thunk that pulls the value from the +// closure and calls the method with the remaining arguments. + +// Because method values are not common, we don't build all thunks for +// all possible interface methods, but instead only build them as we +// need them. In particular, we even build them on demand for +// interface methods defined in other packages. + +Interface_field_reference_expression::Interface_method_thunks + Interface_field_reference_expression::interface_method_thunks; + +// Find or create the thunk to call method NAME on TYPE. + +Named_object* +Interface_field_reference_expression::create_thunk(Gogo* gogo, + Interface_type* type, + const std::string& name) +{ + std::pair<Interface_type*, Method_thunks*> val(type, NULL); + std::pair<Interface_method_thunks::iterator, bool> ins = + Interface_field_reference_expression::interface_method_thunks.insert(val); + if (ins.second) + { + // This is the first time we have seen this interface. + ins.first->second = new Method_thunks(); + } + + for (Method_thunks::const_iterator p = ins.first->second->begin(); + p != ins.first->second->end(); + p++) + if (p->first == name) + return p->second; + + Location loc = type->location(); + + const Typed_identifier* method_id = type->find_method(name); + if (method_id == NULL) + return Named_object::make_erroneous_name(Gogo::thunk_name()); + + Function_type* orig_fntype = method_id->type()->function_type(); + if (orig_fntype == NULL) + return Named_object::make_erroneous_name(Gogo::thunk_name()); + + Struct_field_list* sfl = new Struct_field_list(); + // The type here is wrong--it should be the C function type. But it + // doesn't really matter. + Type* vt = Type::make_pointer_type(Type::make_void_type()); + sfl->push_back(Struct_field(Typed_identifier("fn.0", vt, loc))); + sfl->push_back(Struct_field(Typed_identifier("val.1", type, loc))); + Type* closure_type = Type::make_struct_type(sfl, loc); + closure_type = Type::make_pointer_type(closure_type); + + Function_type* new_fntype = orig_fntype->copy_with_names(); + + Named_object* new_no = gogo->start_function(Gogo::thunk_name(), new_fntype, + false, loc); + + Variable* cvar = new Variable(closure_type, NULL, false, false, false, loc); + cvar->set_is_used(); + Named_object* cp = Named_object::make_variable("$closure", NULL, cvar); + new_no->func_value()->set_closure_var(cp); + + gogo->start_block(loc); + + // Field 0 of the closure is the function code pointer, field 1 is + // the value on which to invoke the method. + Expression* arg = Expression::make_var_reference(cp, loc); + arg = Expression::make_unary(OPERATOR_MULT, arg, loc); + arg = Expression::make_field_reference(arg, 1, loc); + + Expression *ifre = Expression::make_interface_field_reference(arg, name, + loc); + + const Typed_identifier_list* orig_params = orig_fntype->parameters(); + Expression_list* args; + if (orig_params == NULL || orig_params->empty()) + args = NULL; + else + { + const Typed_identifier_list* new_params = new_fntype->parameters(); + args = new Expression_list(); + for (Typed_identifier_list::const_iterator p = new_params->begin(); + p != new_params->end(); + ++p) + { + Named_object* p_no = gogo->lookup(p->name(), NULL); + go_assert(p_no != NULL + && p_no->is_variable() + && p_no->var_value()->is_parameter()); + args->push_back(Expression::make_var_reference(p_no, loc)); + } + } + + Call_expression* call = Expression::make_call(ifre, args, + orig_fntype->is_varargs(), + loc); + call->set_varargs_are_lowered(); + + Statement* s = Statement::make_return_from_call(call, loc); + gogo->add_statement(s); + Block* b = gogo->finish_block(loc); + gogo->add_block(b, loc); + gogo->lower_block(new_no, b); + gogo->flatten_block(new_no, b); + gogo->finish_function(loc); + + ins.first->second->push_back(std::make_pair(name, new_no)); + return new_no; +} + +// Get a tree for a method value. + +tree +Interface_field_reference_expression::do_get_tree(Translate_context* context) +{ + Interface_type* type = this->expr_->type()->interface_type(); + if (type == NULL) + { + go_assert(saw_errors()); + return error_mark_node; + } + + Named_object* thunk = + Interface_field_reference_expression::create_thunk(context->gogo(), + type, this->name_); + if (thunk->is_erroneous()) + { + go_assert(saw_errors()); + return error_mark_node; + } + + // FIXME: We should lower this earlier, but we can't it lower it in + // the lowering pass because at that point we don't know whether we + // need to create the thunk or not. If the expression is called, we + // don't need the thunk. + + Location loc = this->location(); + + Struct_field_list* fields = new Struct_field_list(); + fields->push_back(Struct_field(Typed_identifier("fn.0", + thunk->func_value()->type(), + loc))); + fields->push_back(Struct_field(Typed_identifier("val.1", + this->expr_->type(), + loc))); + Struct_type* st = Type::make_struct_type(fields, loc); + + Expression_list* vals = new Expression_list(); + vals->push_back(Expression::make_func_code_reference(thunk, loc)); + vals->push_back(this->expr_); + + Expression* expr = Expression::make_struct_composite_literal(st, vals, loc); + expr = Expression::make_heap_composite(expr, loc); + + Bexpression* bclosure = tree_to_expr(expr->get_tree(context)); + Expression* nil_check = + Expression::make_binary(OPERATOR_EQEQ, this->expr_, + Expression::make_nil(loc), loc); + Bexpression* bnil_check = tree_to_expr(nil_check->get_tree(context)); + + Gogo* gogo = context->gogo(); + Expression* crash = gogo->runtime_error(RUNTIME_ERROR_NIL_DEREFERENCE, loc); + Bexpression* bcrash = tree_to_expr(crash->get_tree(context)); + + Bexpression* bcond = + gogo->backend()->conditional_expression(NULL, bnil_check, bcrash, NULL, loc); + Bstatement* cond_statement = gogo->backend()->expression_statement(bcond); + Bexpression* ret = + gogo->backend()->compound_expression(cond_statement, bclosure, loc); + return expr_to_tree(ret); +} + +// Dump ast representation for an interface field reference. + +void +Interface_field_reference_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + this->expr_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << "." << this->name_; +} + +// Make a reference to a field in an interface. + +Expression* +Expression::make_interface_field_reference(Expression* expr, + const std::string& field, + Location location) +{ + return new Interface_field_reference_expression(expr, field, location); +} + +// A general selector. This is a Parser_expression for LEFT.NAME. It +// is lowered after we know the type of the left hand side. + +class Selector_expression : public Parser_expression +{ + public: + Selector_expression(Expression* left, const std::string& name, + Location location) + : Parser_expression(EXPRESSION_SELECTOR, location), + left_(left), name_(name) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return Expression::traverse(&this->left_, traverse); } + + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int); + + Expression* + do_copy() + { + return new Selector_expression(this->left_->copy(), this->name_, + this->location()); + } + + void + do_dump_expression(Ast_dump_context* ast_dump_context) const; + + private: + Expression* + lower_method_expression(Gogo*); + + // The expression on the left hand side. + Expression* left_; + // The name on the right hand side. + std::string name_; +}; + +// Lower a selector expression once we know the real type of the left +// hand side. + +Expression* +Selector_expression::do_lower(Gogo* gogo, Named_object*, Statement_inserter*, + int) +{ + Expression* left = this->left_; + if (left->is_type_expression()) + return this->lower_method_expression(gogo); + return Type::bind_field_or_method(gogo, left->type(), left, this->name_, + this->location()); +} + +// Lower a method expression T.M or (*T).M. We turn this into a +// function literal. + +Expression* +Selector_expression::lower_method_expression(Gogo* gogo) +{ + Location location = this->location(); + Type* type = this->left_->type(); + const std::string& name(this->name_); + + bool is_pointer; + if (type->points_to() == NULL) + is_pointer = false; + else + { + is_pointer = true; + type = type->points_to(); + } + Named_type* nt = type->named_type(); + if (nt == NULL) + { + error_at(location, + ("method expression requires named type or " + "pointer to named type")); + return Expression::make_error(location); + } + + bool is_ambiguous; + Method* method = nt->method_function(name, &is_ambiguous); + const Typed_identifier* imethod = NULL; + if (method == NULL && !is_pointer) + { + Interface_type* it = nt->interface_type(); + if (it != NULL) + imethod = it->find_method(name); + } + + if (method == NULL && imethod == NULL) + { + if (!is_ambiguous) + error_at(location, "type %<%s%s%> has no method %<%s%>", + is_pointer ? "*" : "", + nt->message_name().c_str(), + Gogo::message_name(name).c_str()); + else + error_at(location, "method %<%s%s%> is ambiguous in type %<%s%>", + Gogo::message_name(name).c_str(), + is_pointer ? "*" : "", + nt->message_name().c_str()); + return Expression::make_error(location); + } + + if (method != NULL && !is_pointer && !method->is_value_method()) + { + error_at(location, "method requires pointer (use %<(*%s).%s)%>", + nt->message_name().c_str(), + Gogo::message_name(name).c_str()); + return Expression::make_error(location); + } + + // Build a new function type in which the receiver becomes the first + // argument. + Function_type* method_type; + if (method != NULL) + { + method_type = method->type(); + go_assert(method_type->is_method()); + } + else + { + method_type = imethod->type()->function_type(); + go_assert(method_type != NULL && !method_type->is_method()); + } + + const char* const receiver_name = "$this"; + Typed_identifier_list* parameters = new Typed_identifier_list(); + parameters->push_back(Typed_identifier(receiver_name, this->left_->type(), + location)); + + const Typed_identifier_list* method_parameters = method_type->parameters(); + if (method_parameters != NULL) + { + int i = 0; + for (Typed_identifier_list::const_iterator p = method_parameters->begin(); + p != method_parameters->end(); + ++p, ++i) + { + if (!p->name().empty()) + parameters->push_back(*p); + else + { + char buf[20]; + snprintf(buf, sizeof buf, "$param%d", i); + parameters->push_back(Typed_identifier(buf, p->type(), + p->location())); + } + } + } + + const Typed_identifier_list* method_results = method_type->results(); + Typed_identifier_list* results; + if (method_results == NULL) + results = NULL; + else + { + results = new Typed_identifier_list(); + for (Typed_identifier_list::const_iterator p = method_results->begin(); + p != method_results->end(); + ++p) + results->push_back(*p); + } + + Function_type* fntype = Type::make_function_type(NULL, parameters, results, + location); + if (method_type->is_varargs()) + fntype->set_is_varargs(); + + // We generate methods which always takes a pointer to the receiver + // as their first argument. If this is for a pointer type, we can + // simply reuse the existing function. We use an internal hack to + // get the right type. + // FIXME: This optimization is disabled because it doesn't yet work + // with function descriptors when the method expression is not + // directly called. + if (method != NULL && is_pointer && false) + { + Named_object* mno = (method->needs_stub_method() + ? method->stub_object() + : method->named_object()); + Expression* f = Expression::make_func_reference(mno, NULL, location); + f = Expression::make_cast(fntype, f, location); + Type_conversion_expression* tce = + static_cast<Type_conversion_expression*>(f); + tce->set_may_convert_function_types(); + return f; + } + + Named_object* no = gogo->start_function(Gogo::thunk_name(), fntype, false, + location); + + Named_object* vno = gogo->lookup(receiver_name, NULL); + go_assert(vno != NULL); + Expression* ve = Expression::make_var_reference(vno, location); + Expression* bm; + if (method != NULL) + bm = Type::bind_field_or_method(gogo, nt, ve, name, location); + else + bm = Expression::make_interface_field_reference(ve, name, location); + + // Even though we found the method above, if it has an error type we + // may see an error here. + if (bm->is_error_expression()) + { + gogo->finish_function(location); + return bm; + } + + Expression_list* args; + if (parameters->size() <= 1) + args = NULL; + else + { + args = new Expression_list(); + Typed_identifier_list::const_iterator p = parameters->begin(); + ++p; + for (; p != parameters->end(); ++p) + { + vno = gogo->lookup(p->name(), NULL); + go_assert(vno != NULL); + args->push_back(Expression::make_var_reference(vno, location)); + } + } + + gogo->start_block(location); + + Call_expression* call = Expression::make_call(bm, args, + method_type->is_varargs(), + location); + + Statement* s = Statement::make_return_from_call(call, location); + gogo->add_statement(s); + + Block* b = gogo->finish_block(location); + + gogo->add_block(b, location); + + // Lower the call in case there are multiple results. + gogo->lower_block(no, b); + gogo->flatten_block(no, b); + + gogo->finish_function(location); + + return Expression::make_func_reference(no, NULL, location); +} + +// Dump the ast for a selector expression. + +void +Selector_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + ast_dump_context->dump_expression(this->left_); + ast_dump_context->ostream() << "."; + ast_dump_context->ostream() << this->name_; +} + +// Make a selector expression. + +Expression* +Expression::make_selector(Expression* left, const std::string& name, + Location location) +{ + return new Selector_expression(left, name, location); +} + +// Implement the builtin function new. + +class Allocation_expression : public Expression +{ + public: + Allocation_expression(Type* type, Location location) + : Expression(EXPRESSION_ALLOCATION, location), + type_(type) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return Type::traverse(this->type_, traverse); } + + Type* + do_type() + { return Type::make_pointer_type(this->type_); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return new Allocation_expression(this->type_, this->location()); } + + tree + do_get_tree(Translate_context*); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type we are allocating. + Type* type_; +}; + +// Return a tree for an allocation expression. + +tree +Allocation_expression::do_get_tree(Translate_context* context) +{ + tree type_tree = type_to_tree(this->type_->get_backend(context->gogo())); + if (type_tree == error_mark_node) + return error_mark_node; + tree size_tree = TYPE_SIZE_UNIT(type_tree); + tree space = context->gogo()->allocate_memory(this->type_, size_tree, + this->location()); + if (space == error_mark_node) + return error_mark_node; + return fold_convert(build_pointer_type(type_tree), space); +} + +// Dump ast representation for an allocation expression. + +void +Allocation_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + ast_dump_context->ostream() << "new("; + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << ")"; +} + +// Make an allocation expression. + +Expression* +Expression::make_allocation(Type* type, Location location) +{ + return new Allocation_expression(type, location); +} + +// Construct a struct. + +class Struct_construction_expression : public Expression +{ + public: + Struct_construction_expression(Type* type, Expression_list* vals, + Location location) + : Expression(EXPRESSION_STRUCT_CONSTRUCTION, location), + type_(type), vals_(vals), traverse_order_(NULL) + { } + + // Set the traversal order, used to ensure that we implement the + // order of evaluation rules. Takes ownership of the argument. + void + set_traverse_order(std::vector<int>* traverse_order) + { this->traverse_order_ = traverse_order; } + + // Return whether this is a constant initializer. + bool + is_constant_struct() const; + + protected: + int + do_traverse(Traverse* traverse); + + bool + do_is_immutable() const; + + Type* + do_type() + { return this->type_; } + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + Struct_construction_expression* ret = + new Struct_construction_expression(this->type_, this->vals_->copy(), + this->location()); + if (this->traverse_order_ != NULL) + ret->set_traverse_order(this->traverse_order_); + return ret; + } + + tree + do_get_tree(Translate_context*); + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type of the struct to construct. + Type* type_; + // The list of values, in order of the fields in the struct. A NULL + // entry means that the field should be zero-initialized. + Expression_list* vals_; + // If not NULL, the order in which to traverse vals_. This is used + // so that we implement the order of evaluation rules correctly. + std::vector<int>* traverse_order_; +}; + +// Traversal. + +int +Struct_construction_expression::do_traverse(Traverse* traverse) +{ + if (this->vals_ != NULL) + { + if (this->traverse_order_ == NULL) + { + if (this->vals_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + else + { + for (std::vector<int>::const_iterator p = + this->traverse_order_->begin(); + p != this->traverse_order_->end(); + ++p) + { + if (Expression::traverse(&this->vals_->at(*p), traverse) + == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + } + } + if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Return whether this is a constant initializer. + +bool +Struct_construction_expression::is_constant_struct() const +{ + if (this->vals_ == NULL) + return true; + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + if (*pv != NULL + && !(*pv)->is_constant() + && (!(*pv)->is_composite_literal() + || (*pv)->is_nonconstant_composite_literal())) + return false; + } + + const Struct_field_list* fields = this->type_->struct_type()->fields(); + for (Struct_field_list::const_iterator pf = fields->begin(); + pf != fields->end(); + ++pf) + { + // There are no constant constructors for interfaces. + if (pf->type()->interface_type() != NULL) + return false; + } + + return true; +} + +// Return whether this struct is immutable. + +bool +Struct_construction_expression::do_is_immutable() const +{ + if (this->vals_ == NULL) + return true; + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + if (*pv != NULL && !(*pv)->is_immutable()) + return false; + } + return true; +} + +// Final type determination. + +void +Struct_construction_expression::do_determine_type(const Type_context*) +{ + if (this->vals_ == NULL) + return; + const Struct_field_list* fields = this->type_->struct_type()->fields(); + Expression_list::const_iterator pv = this->vals_->begin(); + for (Struct_field_list::const_iterator pf = fields->begin(); + pf != fields->end(); + ++pf, ++pv) + { + if (pv == this->vals_->end()) + return; + if (*pv != NULL) + { + Type_context subcontext(pf->type(), false); + (*pv)->determine_type(&subcontext); + } + } + // Extra values are an error we will report elsewhere; we still want + // to determine the type to avoid knockon errors. + for (; pv != this->vals_->end(); ++pv) + (*pv)->determine_type_no_context(); +} + +// Check types. + +void +Struct_construction_expression::do_check_types(Gogo*) +{ + if (this->vals_ == NULL) + return; + + Struct_type* st = this->type_->struct_type(); + if (this->vals_->size() > st->field_count()) + { + this->report_error(_("too many expressions for struct")); + return; + } + + const Struct_field_list* fields = st->fields(); + Expression_list::const_iterator pv = this->vals_->begin(); + int i = 0; + for (Struct_field_list::const_iterator pf = fields->begin(); + pf != fields->end(); + ++pf, ++pv, ++i) + { + if (pv == this->vals_->end()) + { + this->report_error(_("too few expressions for struct")); + break; + } + + if (*pv == NULL) + continue; + + std::string reason; + if (!Type::are_assignable(pf->type(), (*pv)->type(), &reason)) + { + if (reason.empty()) + error_at((*pv)->location(), + "incompatible type for field %d in struct construction", + i + 1); + else + error_at((*pv)->location(), + ("incompatible type for field %d in " + "struct construction (%s)"), + i + 1, reason.c_str()); + this->set_is_error(); + } + } + go_assert(pv == this->vals_->end()); +} + +// Return a tree for constructing a struct. + +tree +Struct_construction_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + + if (this->vals_ == NULL) + { + Btype* btype = this->type_->get_backend(gogo); + return expr_to_tree(gogo->backend()->zero_expression(btype)); + } + + tree type_tree = type_to_tree(this->type_->get_backend(gogo)); + if (type_tree == error_mark_node) + return error_mark_node; + go_assert(TREE_CODE(type_tree) == RECORD_TYPE); + + bool is_constant = true; + const Struct_field_list* fields = this->type_->struct_type()->fields(); + vec<constructor_elt, va_gc> *elts; + vec_alloc (elts, fields->size()); + Struct_field_list::const_iterator pf = fields->begin(); + Expression_list::const_iterator pv = this->vals_->begin(); + for (tree field = TYPE_FIELDS(type_tree); + field != NULL_TREE; + field = DECL_CHAIN(field), ++pf) + { + go_assert(pf != fields->end()); + + Btype* fbtype = pf->type()->get_backend(gogo); + + tree val; + if (pv == this->vals_->end()) + val = expr_to_tree(gogo->backend()->zero_expression(fbtype)); + else if (*pv == NULL) + { + val = expr_to_tree(gogo->backend()->zero_expression(fbtype)); + ++pv; + } + else + { + val = Expression::convert_for_assignment(context, pf->type(), + (*pv)->type(), + (*pv)->get_tree(context), + this->location()); + ++pv; + } + + if (val == error_mark_node || TREE_TYPE(val) == error_mark_node) + return error_mark_node; + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = elts->quick_push(empty); + elt->index = field; + elt->value = val; + if (!TREE_CONSTANT(val)) + is_constant = false; + } + go_assert(pf == fields->end()); + + tree ret = build_constructor(type_tree, elts); + if (is_constant) + TREE_CONSTANT(ret) = 1; + return ret; +} + +// Export a struct construction. + +void +Struct_construction_expression::do_export(Export* exp) const +{ + exp->write_c_string("convert("); + exp->write_type(this->type_); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + exp->write_c_string(", "); + if (*pv != NULL) + (*pv)->export_expression(exp); + } + exp->write_c_string(")"); +} + +// Dump ast representation of a struct construction expression. + +void +Struct_construction_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << "{"; + ast_dump_context->dump_expression_list(this->vals_); + ast_dump_context->ostream() << "}"; +} + +// Make a struct composite literal. This used by the thunk code. + +Expression* +Expression::make_struct_composite_literal(Type* type, Expression_list* vals, + Location location) +{ + go_assert(type->struct_type() != NULL); + return new Struct_construction_expression(type, vals, location); +} + +// Construct an array. This class is not used directly; instead we +// use the child classes, Fixed_array_construction_expression and +// Open_array_construction_expression. + +class Array_construction_expression : public Expression +{ + protected: + Array_construction_expression(Expression_classification classification, + Type* type, + const std::vector<unsigned long>* indexes, + Expression_list* vals, Location location) + : Expression(classification, location), + type_(type), indexes_(indexes), vals_(vals) + { go_assert(indexes == NULL || indexes->size() == vals->size()); } + + public: + // Return whether this is a constant initializer. + bool + is_constant_array() const; + + // Return the number of elements. + size_t + element_count() const + { return this->vals_ == NULL ? 0 : this->vals_->size(); } + +protected: + int + do_traverse(Traverse* traverse); + + bool + do_is_immutable() const; + + Type* + do_type() + { return this->type_; } + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + void + do_export(Export*) const; + + // The indexes. + const std::vector<unsigned long>* + indexes() + { return this->indexes_; } + + // The list of values. + Expression_list* + vals() + { return this->vals_; } + + // Get a constructor tree for the array values. + tree + get_constructor_tree(Translate_context* context, tree type_tree); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type of the array to construct. + Type* type_; + // The list of indexes into the array, one for each value. This may + // be NULL, in which case the indexes start at zero and increment. + const std::vector<unsigned long>* indexes_; + // The list of values. This may be NULL if there are no values. + Expression_list* vals_; +}; + +// Traversal. + +int +Array_construction_expression::do_traverse(Traverse* traverse) +{ + if (this->vals_ != NULL + && this->vals_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Return whether this is a constant initializer. + +bool +Array_construction_expression::is_constant_array() const +{ + if (this->vals_ == NULL) + return true; + + // There are no constant constructors for interfaces. + if (this->type_->array_type()->element_type()->interface_type() != NULL) + return false; + + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + if (*pv != NULL + && !(*pv)->is_constant() + && (!(*pv)->is_composite_literal() + || (*pv)->is_nonconstant_composite_literal())) + return false; + } + return true; +} + +// Return whether this is an immutable array initializer. + +bool +Array_construction_expression::do_is_immutable() const +{ + if (this->vals_ == NULL) + return true; + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + if (*pv != NULL && !(*pv)->is_immutable()) + return false; + } + return true; +} + +// Final type determination. + +void +Array_construction_expression::do_determine_type(const Type_context*) +{ + if (this->vals_ == NULL) + return; + Type_context subcontext(this->type_->array_type()->element_type(), false); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + if (*pv != NULL) + (*pv)->determine_type(&subcontext); + } +} + +// Check types. + +void +Array_construction_expression::do_check_types(Gogo*) +{ + if (this->vals_ == NULL) + return; + + Array_type* at = this->type_->array_type(); + int i = 0; + Type* element_type = at->element_type(); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv, ++i) + { + if (*pv != NULL + && !Type::are_assignable(element_type, (*pv)->type(), NULL)) + { + error_at((*pv)->location(), + "incompatible type for element %d in composite literal", + i + 1); + this->set_is_error(); + } + } +} + +// Get a constructor tree for the array values. + +tree +Array_construction_expression::get_constructor_tree(Translate_context* context, + tree type_tree) +{ + vec<constructor_elt, va_gc> *values; + vec_alloc (values, (this->vals_ == NULL ? 0 : this->vals_->size())); + Type* element_type = this->type_->array_type()->element_type(); + bool is_constant = true; + if (this->vals_ != NULL) + { + size_t i = 0; + std::vector<unsigned long>::const_iterator pi; + if (this->indexes_ != NULL) + pi = this->indexes_->begin(); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv, ++i) + { + if (this->indexes_ != NULL) + go_assert(pi != this->indexes_->end()); + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = values->quick_push(empty); + + if (this->indexes_ == NULL) + elt->index = size_int(i); + else + elt->index = size_int(*pi); + + if (*pv == NULL) + { + Gogo* gogo = context->gogo(); + Btype* ebtype = element_type->get_backend(gogo); + Bexpression *zv = gogo->backend()->zero_expression(ebtype); + elt->value = expr_to_tree(zv); + } + else + { + tree value_tree = (*pv)->get_tree(context); + elt->value = Expression::convert_for_assignment(context, + element_type, + (*pv)->type(), + value_tree, + this->location()); + } + if (elt->value == error_mark_node) + return error_mark_node; + if (!TREE_CONSTANT(elt->value)) + is_constant = false; + if (this->indexes_ != NULL) + ++pi; + } + if (this->indexes_ != NULL) + go_assert(pi == this->indexes_->end()); + } + + tree ret = build_constructor(type_tree, values); + if (is_constant) + TREE_CONSTANT(ret) = 1; + return ret; +} + +// Export an array construction. + +void +Array_construction_expression::do_export(Export* exp) const +{ + exp->write_c_string("convert("); + exp->write_type(this->type_); + if (this->vals_ != NULL) + { + std::vector<unsigned long>::const_iterator pi; + if (this->indexes_ != NULL) + pi = this->indexes_->begin(); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + exp->write_c_string(", "); + + if (this->indexes_ != NULL) + { + char buf[100]; + snprintf(buf, sizeof buf, "%lu", *pi); + exp->write_c_string(buf); + exp->write_c_string(":"); + } + + if (*pv != NULL) + (*pv)->export_expression(exp); + + if (this->indexes_ != NULL) + ++pi; + } + } + exp->write_c_string(")"); +} + +// Dump ast representation of an array construction expressin. + +void +Array_construction_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + Expression* length = this->type_->array_type()->length(); + + ast_dump_context->ostream() << "[" ; + if (length != NULL) + { + ast_dump_context->dump_expression(length); + } + ast_dump_context->ostream() << "]" ; + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << "{" ; + if (this->indexes_ == NULL) + ast_dump_context->dump_expression_list(this->vals_); + else + { + Expression_list::const_iterator pv = this->vals_->begin(); + for (std::vector<unsigned long>::const_iterator pi = + this->indexes_->begin(); + pi != this->indexes_->end(); + ++pi, ++pv) + { + if (pi != this->indexes_->begin()) + ast_dump_context->ostream() << ", "; + ast_dump_context->ostream() << *pi << ':'; + ast_dump_context->dump_expression(*pv); + } + } + ast_dump_context->ostream() << "}" ; + +} + +// Construct a fixed array. + +class Fixed_array_construction_expression : + public Array_construction_expression +{ + public: + Fixed_array_construction_expression(Type* type, + const std::vector<unsigned long>* indexes, + Expression_list* vals, Location location) + : Array_construction_expression(EXPRESSION_FIXED_ARRAY_CONSTRUCTION, + type, indexes, vals, location) + { go_assert(type->array_type() != NULL && !type->is_slice_type()); } + + protected: + Expression* + do_copy() + { + return new Fixed_array_construction_expression(this->type(), + this->indexes(), + (this->vals() == NULL + ? NULL + : this->vals()->copy()), + this->location()); + } + + tree + do_get_tree(Translate_context*); +}; + +// Return a tree for constructing a fixed array. + +tree +Fixed_array_construction_expression::do_get_tree(Translate_context* context) +{ + Type* type = this->type(); + Btype* btype = type->get_backend(context->gogo()); + return this->get_constructor_tree(context, type_to_tree(btype)); +} + +// Construct an open array. + +class Open_array_construction_expression : public Array_construction_expression +{ + public: + Open_array_construction_expression(Type* type, + const std::vector<unsigned long>* indexes, + Expression_list* vals, Location location) + : Array_construction_expression(EXPRESSION_OPEN_ARRAY_CONSTRUCTION, + type, indexes, vals, location) + { go_assert(type->is_slice_type()); } + + protected: + // Note that taking the address of an open array literal is invalid. + + Expression* + do_copy() + { + return new Open_array_construction_expression(this->type(), + this->indexes(), + (this->vals() == NULL + ? NULL + : this->vals()->copy()), + this->location()); + } + + tree + do_get_tree(Translate_context*); +}; + +// Return a tree for constructing an open array. + +tree +Open_array_construction_expression::do_get_tree(Translate_context* context) +{ + Array_type* array_type = this->type()->array_type(); + if (array_type == NULL) + { + go_assert(this->type()->is_error()); + return error_mark_node; + } + + Type* element_type = array_type->element_type(); + Btype* belement_type = element_type->get_backend(context->gogo()); + tree element_type_tree = type_to_tree(belement_type); + if (element_type_tree == error_mark_node) + return error_mark_node; + + tree values; + tree length_tree; + if (this->vals() == NULL || this->vals()->empty()) + { + // We need to create a unique value. + tree max = size_int(0); + tree constructor_type = build_array_type(element_type_tree, + build_index_type(max)); + if (constructor_type == error_mark_node) + return error_mark_node; + vec<constructor_elt, va_gc> *vec; + vec_alloc(vec, 1); + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = vec->quick_push(empty); + elt->index = size_int(0); + Gogo* gogo = context->gogo(); + Btype* btype = element_type->get_backend(gogo); + elt->value = expr_to_tree(gogo->backend()->zero_expression(btype)); + values = build_constructor(constructor_type, vec); + if (TREE_CONSTANT(elt->value)) + TREE_CONSTANT(values) = 1; + length_tree = size_int(0); + } + else + { + unsigned long max_index; + if (this->indexes() == NULL) + max_index = this->vals()->size() - 1; + else + max_index = this->indexes()->back(); + tree max_tree = size_int(max_index); + tree constructor_type = build_array_type(element_type_tree, + build_index_type(max_tree)); + if (constructor_type == error_mark_node) + return error_mark_node; + values = this->get_constructor_tree(context, constructor_type); + length_tree = size_int(max_index + 1); + } + + if (values == error_mark_node) + return error_mark_node; + + bool is_constant_initializer = TREE_CONSTANT(values); + + // We have to copy the initial values into heap memory if we are in + // a function or if the values are not constants. We also have to + // copy them if they may contain pointers in a non-constant context, + // as otherwise the garbage collector won't see them. + bool copy_to_heap = (context->function() != NULL + || !is_constant_initializer + || (element_type->has_pointer() + && !context->is_const())); + + if (is_constant_initializer) + { + tree tmp = build_decl(this->location().gcc_location(), VAR_DECL, + create_tmp_var_name("C"), TREE_TYPE(values)); + DECL_EXTERNAL(tmp) = 0; + TREE_PUBLIC(tmp) = 0; + TREE_STATIC(tmp) = 1; + DECL_ARTIFICIAL(tmp) = 1; + if (copy_to_heap) + { + // If we are not copying the value to the heap, we will only + // initialize the value once, so we can use this directly + // rather than copying it. In that case we can't make it + // read-only, because the program is permitted to change it. + TREE_READONLY(tmp) = 1; + TREE_CONSTANT(tmp) = 1; + } + DECL_INITIAL(tmp) = values; + rest_of_decl_compilation(tmp, 1, 0); + values = tmp; + } + + tree space; + tree set; + if (!copy_to_heap) + { + // the initializer will only run once. + space = build_fold_addr_expr(values); + set = NULL_TREE; + } + else + { + tree memsize = TYPE_SIZE_UNIT(TREE_TYPE(values)); + space = context->gogo()->allocate_memory(element_type, memsize, + this->location()); + space = save_expr(space); + + tree s = fold_convert(build_pointer_type(TREE_TYPE(values)), space); + tree ref = build_fold_indirect_ref_loc(this->location().gcc_location(), + s); + TREE_THIS_NOTRAP(ref) = 1; + set = build2(MODIFY_EXPR, void_type_node, ref, values); + } + + // Build a constructor for the open array. + + tree type_tree = type_to_tree(this->type()->get_backend(context->gogo())); + if (type_tree == error_mark_node) + return error_mark_node; + go_assert(TREE_CODE(type_tree) == RECORD_TYPE); + + vec<constructor_elt, va_gc> *init; + vec_alloc(init, 3); + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = init->quick_push(empty); + tree field = TYPE_FIELDS(type_tree); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__values") == 0); + elt->index = field; + elt->value = fold_convert(TREE_TYPE(field), space); + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)), "__count") == 0); + elt->index = field; + elt->value = fold_convert(TREE_TYPE(field), length_tree); + + elt = init->quick_push(empty); + field = DECL_CHAIN(field); + go_assert(strcmp(IDENTIFIER_POINTER(DECL_NAME(field)),"__capacity") == 0); + elt->index = field; + elt->value = fold_convert(TREE_TYPE(field), length_tree); + + tree constructor = build_constructor(type_tree, init); + if (constructor == error_mark_node) + return error_mark_node; + if (!copy_to_heap) + TREE_CONSTANT(constructor) = 1; + + if (set == NULL_TREE) + return constructor; + else + return build2(COMPOUND_EXPR, type_tree, set, constructor); +} + +// Make a slice composite literal. This is used by the type +// descriptor code. + +Expression* +Expression::make_slice_composite_literal(Type* type, Expression_list* vals, + Location location) +{ + go_assert(type->is_slice_type()); + return new Open_array_construction_expression(type, NULL, vals, location); +} + +// Construct a map. + +class Map_construction_expression : public Expression +{ + public: + Map_construction_expression(Type* type, Expression_list* vals, + Location location) + : Expression(EXPRESSION_MAP_CONSTRUCTION, location), + type_(type), vals_(vals) + { go_assert(vals == NULL || vals->size() % 2 == 0); } + + protected: + int + do_traverse(Traverse* traverse); + + Type* + do_type() + { return this->type_; } + + void + do_determine_type(const Type_context*); + + void + do_check_types(Gogo*); + + Expression* + do_copy() + { + return new Map_construction_expression(this->type_, this->vals_->copy(), + this->location()); + } + + tree + do_get_tree(Translate_context*); + + void + do_export(Export*) const; + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type of the map to construct. + Type* type_; + // The list of values. + Expression_list* vals_; +}; + +// Traversal. + +int +Map_construction_expression::do_traverse(Traverse* traverse) +{ + if (this->vals_ != NULL + && this->vals_->traverse(traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Final type determination. + +void +Map_construction_expression::do_determine_type(const Type_context*) +{ + if (this->vals_ == NULL) + return; + + Map_type* mt = this->type_->map_type(); + Type_context key_context(mt->key_type(), false); + Type_context val_context(mt->val_type(), false); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + (*pv)->determine_type(&key_context); + ++pv; + (*pv)->determine_type(&val_context); + } +} + +// Check types. + +void +Map_construction_expression::do_check_types(Gogo*) +{ + if (this->vals_ == NULL) + return; + + Map_type* mt = this->type_->map_type(); + int i = 0; + Type* key_type = mt->key_type(); + Type* val_type = mt->val_type(); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv, ++i) + { + if (!Type::are_assignable(key_type, (*pv)->type(), NULL)) + { + error_at((*pv)->location(), + "incompatible type for element %d key in map construction", + i + 1); + this->set_is_error(); + } + ++pv; + if (!Type::are_assignable(val_type, (*pv)->type(), NULL)) + { + error_at((*pv)->location(), + ("incompatible type for element %d value " + "in map construction"), + i + 1); + this->set_is_error(); + } + } +} + +// Return a tree for constructing a map. + +tree +Map_construction_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Location loc = this->location(); + + Map_type* mt = this->type_->map_type(); + + // Build a struct to hold the key and value. + tree struct_type = make_node(RECORD_TYPE); + + Type* key_type = mt->key_type(); + tree id = get_identifier("__key"); + tree key_type_tree = type_to_tree(key_type->get_backend(gogo)); + if (key_type_tree == error_mark_node) + return error_mark_node; + tree key_field = build_decl(loc.gcc_location(), FIELD_DECL, id, + key_type_tree); + DECL_CONTEXT(key_field) = struct_type; + TYPE_FIELDS(struct_type) = key_field; + + Type* val_type = mt->val_type(); + id = get_identifier("__val"); + tree val_type_tree = type_to_tree(val_type->get_backend(gogo)); + if (val_type_tree == error_mark_node) + return error_mark_node; + tree val_field = build_decl(loc.gcc_location(), FIELD_DECL, id, + val_type_tree); + DECL_CONTEXT(val_field) = struct_type; + DECL_CHAIN(key_field) = val_field; + + layout_type(struct_type); + + bool is_constant = true; + size_t i = 0; + tree valaddr; + tree make_tmp; + + if (this->vals_ == NULL || this->vals_->empty()) + { + valaddr = null_pointer_node; + make_tmp = NULL_TREE; + } + else + { + vec<constructor_elt, va_gc> *values; + vec_alloc(values, this->vals_->size() / 2); + + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv, ++i) + { + bool one_is_constant = true; + + vec<constructor_elt, va_gc> *one; + vec_alloc(one, 2); + + constructor_elt empty = {NULL, NULL}; + constructor_elt* elt = one->quick_push(empty); + elt->index = key_field; + tree val_tree = (*pv)->get_tree(context); + elt->value = Expression::convert_for_assignment(context, key_type, + (*pv)->type(), + val_tree, loc); + if (elt->value == error_mark_node) + return error_mark_node; + if (!TREE_CONSTANT(elt->value)) + one_is_constant = false; + + ++pv; + + elt = one->quick_push(empty); + elt->index = val_field; + val_tree = (*pv)->get_tree(context); + elt->value = Expression::convert_for_assignment(context, val_type, + (*pv)->type(), + val_tree, loc); + if (elt->value == error_mark_node) + return error_mark_node; + if (!TREE_CONSTANT(elt->value)) + one_is_constant = false; + + elt = values->quick_push(empty); + elt->index = size_int(i); + elt->value = build_constructor(struct_type, one); + if (one_is_constant) + TREE_CONSTANT(elt->value) = 1; + else + is_constant = false; + } + + tree index_type = build_index_type(size_int(i - 1)); + tree array_type = build_array_type(struct_type, index_type); + tree init = build_constructor(array_type, values); + if (is_constant) + TREE_CONSTANT(init) = 1; + tree tmp; + if (current_function_decl != NULL) + { + tmp = create_tmp_var(array_type, get_name(array_type)); + DECL_INITIAL(tmp) = init; + make_tmp = fold_build1_loc(loc.gcc_location(), DECL_EXPR, + void_type_node, tmp); + TREE_ADDRESSABLE(tmp) = 1; + } + else + { + tmp = build_decl(loc.gcc_location(), VAR_DECL, + create_tmp_var_name("M"), array_type); + DECL_EXTERNAL(tmp) = 0; + TREE_PUBLIC(tmp) = 0; + TREE_STATIC(tmp) = 1; + DECL_ARTIFICIAL(tmp) = 1; + if (!TREE_CONSTANT(init)) + make_tmp = fold_build2_loc(loc.gcc_location(), INIT_EXPR, + void_type_node, tmp, init); + else + { + TREE_READONLY(tmp) = 1; + TREE_CONSTANT(tmp) = 1; + DECL_INITIAL(tmp) = init; + make_tmp = NULL_TREE; + } + rest_of_decl_compilation(tmp, 1, 0); + } + + valaddr = build_fold_addr_expr(tmp); + } + + Bexpression* bdescriptor = mt->map_descriptor_pointer(gogo, loc); + tree descriptor = expr_to_tree(bdescriptor); + + tree type_tree = type_to_tree(this->type_->get_backend(gogo)); + if (type_tree == error_mark_node) + return error_mark_node; + + static tree construct_map_fndecl; + tree call = Gogo::call_builtin(&construct_map_fndecl, + loc, + "__go_construct_map", + 6, + type_tree, + TREE_TYPE(descriptor), + descriptor, + sizetype, + size_int(i), + sizetype, + TYPE_SIZE_UNIT(struct_type), + sizetype, + byte_position(val_field), + sizetype, + TYPE_SIZE_UNIT(TREE_TYPE(val_field)), + const_ptr_type_node, + fold_convert(const_ptr_type_node, valaddr)); + if (call == error_mark_node) + return error_mark_node; + + tree ret; + if (make_tmp == NULL) + ret = call; + else + ret = fold_build2_loc(loc.gcc_location(), COMPOUND_EXPR, type_tree, + make_tmp, call); + return ret; +} + +// Export an array construction. + +void +Map_construction_expression::do_export(Export* exp) const +{ + exp->write_c_string("convert("); + exp->write_type(this->type_); + for (Expression_list::const_iterator pv = this->vals_->begin(); + pv != this->vals_->end(); + ++pv) + { + exp->write_c_string(", "); + (*pv)->export_expression(exp); + } + exp->write_c_string(")"); +} + +// Dump ast representation for a map construction expression. + +void +Map_construction_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "{" ; + ast_dump_context->dump_expression_list(this->vals_, true); + ast_dump_context->ostream() << "}"; +} + +// A general composite literal. This is lowered to a type specific +// version. + +class Composite_literal_expression : public Parser_expression +{ + public: + Composite_literal_expression(Type* type, int depth, bool has_keys, + Expression_list* vals, bool all_are_names, + Location location) + : Parser_expression(EXPRESSION_COMPOSITE_LITERAL, location), + type_(type), depth_(depth), vals_(vals), has_keys_(has_keys), + all_are_names_(all_are_names) + { } + + protected: + int + do_traverse(Traverse* traverse); + + Expression* + do_lower(Gogo*, Named_object*, Statement_inserter*, int); + + Expression* + do_copy() + { + return new Composite_literal_expression(this->type_, this->depth_, + this->has_keys_, + (this->vals_ == NULL + ? NULL + : this->vals_->copy()), + this->all_are_names_, + this->location()); + } + + void + do_dump_expression(Ast_dump_context*) const; + + private: + Expression* + lower_struct(Gogo*, Type*); + + Expression* + lower_array(Type*); + + Expression* + make_array(Type*, const std::vector<unsigned long>*, Expression_list*); + + Expression* + lower_map(Gogo*, Named_object*, Statement_inserter*, Type*); + + // The type of the composite literal. + Type* type_; + // The depth within a list of composite literals within a composite + // literal, when the type is omitted. + int depth_; + // The values to put in the composite literal. + Expression_list* vals_; + // If this is true, then VALS_ is a list of pairs: a key and a + // value. In an array initializer, a missing key will be NULL. + bool has_keys_; + // If this is true, then HAS_KEYS_ is true, and every key is a + // simple identifier. + bool all_are_names_; +}; + +// Traversal. + +int +Composite_literal_expression::do_traverse(Traverse* traverse) +{ + if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + + // If this is a struct composite literal with keys, then the keys + // are field names, not expressions. We don't want to traverse them + // in that case. If we do, we can give an erroneous error "variable + // initializer refers to itself." See bug482.go in the testsuite. + if (this->has_keys_ && this->vals_ != NULL) + { + // The type may not be resolvable at this point. + Type* type = this->type_; + + for (int depth = this->depth_; depth > 0; --depth) + { + if (type->array_type() != NULL) + type = type->array_type()->element_type(); + else if (type->map_type() != NULL) + type = type->map_type()->val_type(); + else + { + // This error will be reported during lowering. + return TRAVERSE_CONTINUE; + } + } + + while (true) + { + if (type->classification() == Type::TYPE_NAMED) + type = type->named_type()->real_type(); + else if (type->classification() == Type::TYPE_FORWARD) + { + Type* t = type->forwarded(); + if (t == type) + break; + type = t; + } + else + break; + } + + if (type->classification() == Type::TYPE_STRUCT) + { + Expression_list::iterator p = this->vals_->begin(); + while (p != this->vals_->end()) + { + // Skip key. + ++p; + go_assert(p != this->vals_->end()); + if (Expression::traverse(&*p, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + ++p; + } + return TRAVERSE_CONTINUE; + } + } + + if (this->vals_ != NULL) + return this->vals_->traverse(traverse); + + return TRAVERSE_CONTINUE; +} + +// Lower a generic composite literal into a specific version based on +// the type. + +Expression* +Composite_literal_expression::do_lower(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, int) +{ + Type* type = this->type_; + + for (int depth = this->depth_; depth > 0; --depth) + { + if (type->array_type() != NULL) + type = type->array_type()->element_type(); + else if (type->map_type() != NULL) + type = type->map_type()->val_type(); + else + { + if (!type->is_error()) + error_at(this->location(), + ("may only omit types within composite literals " + "of slice, array, or map type")); + return Expression::make_error(this->location()); + } + } + + Type *pt = type->points_to(); + bool is_pointer = false; + if (pt != NULL) + { + is_pointer = true; + type = pt; + } + + Expression* ret; + if (type->is_error()) + return Expression::make_error(this->location()); + else if (type->struct_type() != NULL) + ret = this->lower_struct(gogo, type); + else if (type->array_type() != NULL) + ret = this->lower_array(type); + else if (type->map_type() != NULL) + ret = this->lower_map(gogo, function, inserter, type); + else + { + error_at(this->location(), + ("expected struct, slice, array, or map type " + "for composite literal")); + return Expression::make_error(this->location()); + } + + if (is_pointer) + ret = Expression::make_heap_composite(ret, this->location()); + + return ret; +} + +// Lower a struct composite literal. + +Expression* +Composite_literal_expression::lower_struct(Gogo* gogo, Type* type) +{ + Location location = this->location(); + Struct_type* st = type->struct_type(); + if (this->vals_ == NULL || !this->has_keys_) + { + if (this->vals_ != NULL + && !this->vals_->empty() + && type->named_type() != NULL + && type->named_type()->named_object()->package() != NULL) + { + for (Struct_field_list::const_iterator pf = st->fields()->begin(); + pf != st->fields()->end(); + ++pf) + { + if (Gogo::is_hidden_name(pf->field_name())) + error_at(this->location(), + "assignment of unexported field %qs in %qs literal", + Gogo::message_name(pf->field_name()).c_str(), + type->named_type()->message_name().c_str()); + } + } + + return new Struct_construction_expression(type, this->vals_, location); + } + + size_t field_count = st->field_count(); + std::vector<Expression*> vals(field_count); + std::vector<int>* traverse_order = new(std::vector<int>); + Expression_list::const_iterator p = this->vals_->begin(); + Expression* external_expr = NULL; + const Named_object* external_no = NULL; + while (p != this->vals_->end()) + { + Expression* name_expr = *p; + + ++p; + go_assert(p != this->vals_->end()); + Expression* val = *p; + + ++p; + + if (name_expr == NULL) + { + error_at(val->location(), "mixture of field and value initializers"); + return Expression::make_error(location); + } + + bool bad_key = false; + std::string name; + const Named_object* no = NULL; + switch (name_expr->classification()) + { + case EXPRESSION_UNKNOWN_REFERENCE: + name = name_expr->unknown_expression()->name(); + break; + + case EXPRESSION_CONST_REFERENCE: + no = static_cast<Const_expression*>(name_expr)->named_object(); + break; + + case EXPRESSION_TYPE: + { + Type* t = name_expr->type(); + Named_type* nt = t->named_type(); + if (nt == NULL) + bad_key = true; + else + no = nt->named_object(); + } + break; + + case EXPRESSION_VAR_REFERENCE: + no = name_expr->var_expression()->named_object(); + break; + + case EXPRESSION_FUNC_REFERENCE: + no = name_expr->func_expression()->named_object(); + break; + + case EXPRESSION_UNARY: + // If there is a local variable around with the same name as + // the field, and this occurs in the closure, then the + // parser may turn the field reference into an indirection + // through the closure. FIXME: This is a mess. + { + bad_key = true; + Unary_expression* ue = static_cast<Unary_expression*>(name_expr); + if (ue->op() == OPERATOR_MULT) + { + Field_reference_expression* fre = + ue->operand()->field_reference_expression(); + if (fre != NULL) + { + Struct_type* st = + fre->expr()->type()->deref()->struct_type(); + if (st != NULL) + { + const Struct_field* sf = st->field(fre->field_index()); + name = sf->field_name(); + + // See below. FIXME. + if (!Gogo::is_hidden_name(name) + && name[0] >= 'a' + && name[0] <= 'z') + { + if (gogo->lookup_global(name.c_str()) != NULL) + name = gogo->pack_hidden_name(name, false); + } + + char buf[20]; + snprintf(buf, sizeof buf, "%u", fre->field_index()); + size_t buflen = strlen(buf); + if (name.compare(name.length() - buflen, buflen, buf) + == 0) + { + name = name.substr(0, name.length() - buflen); + bad_key = false; + } + } + } + } + } + break; + + default: + bad_key = true; + break; + } + if (bad_key) + { + error_at(name_expr->location(), "expected struct field name"); + return Expression::make_error(location); + } + + if (no != NULL) + { + if (no->package() != NULL && external_expr == NULL) + { + external_expr = name_expr; + external_no = no; + } + + name = no->name(); + + // A predefined name won't be packed. If it starts with a + // lower case letter we need to check for that case, because + // the field name will be packed. FIXME. + if (!Gogo::is_hidden_name(name) + && name[0] >= 'a' + && name[0] <= 'z') + { + Named_object* gno = gogo->lookup_global(name.c_str()); + if (gno == no) + name = gogo->pack_hidden_name(name, false); + } + } + + unsigned int index; + const Struct_field* sf = st->find_local_field(name, &index); + if (sf == NULL) + { + error_at(name_expr->location(), "unknown field %qs in %qs", + Gogo::message_name(name).c_str(), + (type->named_type() != NULL + ? type->named_type()->message_name().c_str() + : "unnamed struct")); + return Expression::make_error(location); + } + if (vals[index] != NULL) + { + error_at(name_expr->location(), + "duplicate value for field %qs in %qs", + Gogo::message_name(name).c_str(), + (type->named_type() != NULL + ? type->named_type()->message_name().c_str() + : "unnamed struct")); + return Expression::make_error(location); + } + + if (type->named_type() != NULL + && type->named_type()->named_object()->package() != NULL + && Gogo::is_hidden_name(sf->field_name())) + error_at(name_expr->location(), + "assignment of unexported field %qs in %qs literal", + Gogo::message_name(sf->field_name()).c_str(), + type->named_type()->message_name().c_str()); + + vals[index] = val; + traverse_order->push_back(index); + } + + if (!this->all_are_names_) + { + // This is a weird case like bug462 in the testsuite. + if (external_expr == NULL) + error_at(this->location(), "unknown field in %qs literal", + (type->named_type() != NULL + ? type->named_type()->message_name().c_str() + : "unnamed struct")); + else + error_at(external_expr->location(), "unknown field %qs in %qs", + external_no->message_name().c_str(), + (type->named_type() != NULL + ? type->named_type()->message_name().c_str() + : "unnamed struct")); + return Expression::make_error(location); + } + + Expression_list* list = new Expression_list; + list->reserve(field_count); + for (size_t i = 0; i < field_count; ++i) + list->push_back(vals[i]); + + Struct_construction_expression* ret = + new Struct_construction_expression(type, list, location); + ret->set_traverse_order(traverse_order); + return ret; +} + +// Used to sort an index/value array. + +class Index_value_compare +{ + public: + bool + operator()(const std::pair<unsigned long, Expression*>& a, + const std::pair<unsigned long, Expression*>& b) + { return a.first < b.first; } +}; + +// Lower an array composite literal. + +Expression* +Composite_literal_expression::lower_array(Type* type) +{ + Location location = this->location(); + if (this->vals_ == NULL || !this->has_keys_) + return this->make_array(type, NULL, this->vals_); + + std::vector<unsigned long>* indexes = new std::vector<unsigned long>; + indexes->reserve(this->vals_->size()); + bool indexes_out_of_order = false; + Expression_list* vals = new Expression_list(); + vals->reserve(this->vals_->size()); + unsigned long index = 0; + Expression_list::const_iterator p = this->vals_->begin(); + while (p != this->vals_->end()) + { + Expression* index_expr = *p; + + ++p; + go_assert(p != this->vals_->end()); + Expression* val = *p; + + ++p; + + if (index_expr == NULL) + { + if (!indexes->empty()) + indexes->push_back(index); + } + else + { + if (indexes->empty() && !vals->empty()) + { + for (size_t i = 0; i < vals->size(); ++i) + indexes->push_back(i); + } + + Numeric_constant nc; + if (!index_expr->numeric_constant_value(&nc)) + { + error_at(index_expr->location(), + "index expression is not integer constant"); + return Expression::make_error(location); + } + + switch (nc.to_unsigned_long(&index)) + { + case Numeric_constant::NC_UL_VALID: + break; + case Numeric_constant::NC_UL_NOTINT: + error_at(index_expr->location(), + "index expression is not integer constant"); + return Expression::make_error(location); + case Numeric_constant::NC_UL_NEGATIVE: + error_at(index_expr->location(), "index expression is negative"); + return Expression::make_error(location); + case Numeric_constant::NC_UL_BIG: + error_at(index_expr->location(), "index value overflow"); + return Expression::make_error(location); + default: + go_unreachable(); + } + + Named_type* ntype = Type::lookup_integer_type("int"); + Integer_type* inttype = ntype->integer_type(); + if (sizeof(index) <= static_cast<size_t>(inttype->bits() * 8) + && index >> (inttype->bits() - 1) != 0) + { + error_at(index_expr->location(), "index value overflow"); + return Expression::make_error(location); + } + + if (std::find(indexes->begin(), indexes->end(), index) + != indexes->end()) + { + error_at(index_expr->location(), "duplicate value for index %lu", + index); + return Expression::make_error(location); + } + + if (!indexes->empty() && index < indexes->back()) + indexes_out_of_order = true; + + indexes->push_back(index); + } + + vals->push_back(val); + + ++index; + } + + if (indexes->empty()) + { + delete indexes; + indexes = NULL; + } + + if (indexes_out_of_order) + { + typedef std::vector<std::pair<unsigned long, Expression*> > V; + + V v; + v.reserve(indexes->size()); + std::vector<unsigned long>::const_iterator pi = indexes->begin(); + for (Expression_list::const_iterator pe = vals->begin(); + pe != vals->end(); + ++pe, ++pi) + v.push_back(std::make_pair(*pi, *pe)); + + std::sort(v.begin(), v.end(), Index_value_compare()); + + delete indexes; + delete vals; + indexes = new std::vector<unsigned long>(); + indexes->reserve(v.size()); + vals = new Expression_list(); + vals->reserve(v.size()); + + for (V::const_iterator p = v.begin(); p != v.end(); ++p) + { + indexes->push_back(p->first); + vals->push_back(p->second); + } + } + + return this->make_array(type, indexes, vals); +} + +// Actually build the array composite literal. This handles +// [...]{...}. + +Expression* +Composite_literal_expression::make_array( + Type* type, + const std::vector<unsigned long>* indexes, + Expression_list* vals) +{ + Location location = this->location(); + Array_type* at = type->array_type(); + + if (at->length() != NULL && at->length()->is_nil_expression()) + { + size_t size; + if (vals == NULL) + size = 0; + else if (indexes != NULL) + size = indexes->back() + 1; + else + { + size = vals->size(); + Integer_type* it = Type::lookup_integer_type("int")->integer_type(); + if (sizeof(size) <= static_cast<size_t>(it->bits() * 8) + && size >> (it->bits() - 1) != 0) + { + error_at(location, "too many elements in composite literal"); + return Expression::make_error(location); + } + } + + mpz_t vlen; + mpz_init_set_ui(vlen, size); + Expression* elen = Expression::make_integer(&vlen, NULL, location); + mpz_clear(vlen); + at = Type::make_array_type(at->element_type(), elen); + type = at; + } + else if (at->length() != NULL + && !at->length()->is_error_expression() + && this->vals_ != NULL) + { + Numeric_constant nc; + unsigned long val; + if (at->length()->numeric_constant_value(&nc) + && nc.to_unsigned_long(&val) == Numeric_constant::NC_UL_VALID) + { + if (indexes == NULL) + { + if (this->vals_->size() > val) + { + error_at(location, "too many elements in composite literal"); + return Expression::make_error(location); + } + } + else + { + unsigned long max = indexes->back(); + if (max >= val) + { + error_at(location, + ("some element keys in composite literal " + "are out of range")); + return Expression::make_error(location); + } + } + } + } + + if (at->length() != NULL) + return new Fixed_array_construction_expression(type, indexes, vals, + location); + else + return new Open_array_construction_expression(type, indexes, vals, + location); +} + +// Lower a map composite literal. + +Expression* +Composite_literal_expression::lower_map(Gogo* gogo, Named_object* function, + Statement_inserter* inserter, + Type* type) +{ + Location location = this->location(); + if (this->vals_ != NULL) + { + if (!this->has_keys_) + { + error_at(location, "map composite literal must have keys"); + return Expression::make_error(location); + } + + for (Expression_list::iterator p = this->vals_->begin(); + p != this->vals_->end(); + p += 2) + { + if (*p == NULL) + { + ++p; + error_at((*p)->location(), + "map composite literal must have keys for every value"); + return Expression::make_error(location); + } + // Make sure we have lowered the key; it may not have been + // lowered in order to handle keys for struct composite + // literals. Lower it now to get the right error message. + if ((*p)->unknown_expression() != NULL) + { + (*p)->unknown_expression()->clear_is_composite_literal_key(); + gogo->lower_expression(function, inserter, &*p); + go_assert((*p)->is_error_expression()); + return Expression::make_error(location); + } + } + } + + return new Map_construction_expression(type, this->vals_, location); +} + +// Dump ast representation for a composite literal expression. + +void +Composite_literal_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "composite("; + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << ", {"; + ast_dump_context->dump_expression_list(this->vals_, this->has_keys_); + ast_dump_context->ostream() << "})"; +} + +// Make a composite literal expression. + +Expression* +Expression::make_composite_literal(Type* type, int depth, bool has_keys, + Expression_list* vals, bool all_are_names, + Location location) +{ + return new Composite_literal_expression(type, depth, has_keys, vals, + all_are_names, location); +} + +// Return whether this expression is a composite literal. + +bool +Expression::is_composite_literal() const +{ + switch (this->classification_) + { + case EXPRESSION_COMPOSITE_LITERAL: + case EXPRESSION_STRUCT_CONSTRUCTION: + case EXPRESSION_FIXED_ARRAY_CONSTRUCTION: + case EXPRESSION_OPEN_ARRAY_CONSTRUCTION: + case EXPRESSION_MAP_CONSTRUCTION: + return true; + default: + return false; + } +} + +// Return whether this expression is a composite literal which is not +// constant. + +bool +Expression::is_nonconstant_composite_literal() const +{ + switch (this->classification_) + { + case EXPRESSION_STRUCT_CONSTRUCTION: + { + const Struct_construction_expression *psce = + static_cast<const Struct_construction_expression*>(this); + return !psce->is_constant_struct(); + } + case EXPRESSION_FIXED_ARRAY_CONSTRUCTION: + { + const Fixed_array_construction_expression *pace = + static_cast<const Fixed_array_construction_expression*>(this); + return !pace->is_constant_array(); + } + case EXPRESSION_OPEN_ARRAY_CONSTRUCTION: + { + const Open_array_construction_expression *pace = + static_cast<const Open_array_construction_expression*>(this); + return !pace->is_constant_array(); + } + case EXPRESSION_MAP_CONSTRUCTION: + return true; + default: + return false; + } +} + +// Return true if this is a variable or temporary_variable. + +bool +Expression::is_variable() const +{ + switch (this->classification_) + { + case EXPRESSION_VAR_REFERENCE: + case EXPRESSION_TEMPORARY_REFERENCE: + case EXPRESSION_SET_AND_USE_TEMPORARY: + return true; + default: + return false; + } +} + +// Return true if this is a reference to a local variable. + +bool +Expression::is_local_variable() const +{ + const Var_expression* ve = this->var_expression(); + if (ve == NULL) + return false; + const Named_object* no = ve->named_object(); + return (no->is_result_variable() + || (no->is_variable() && !no->var_value()->is_global())); +} + +// Class Type_guard_expression. + +// Traversal. + +int +Type_guard_expression::do_traverse(Traverse* traverse) +{ + if (Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT + || Type::traverse(this->type_, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + return TRAVERSE_CONTINUE; +} + +// Check types of a type guard expression. The expression must have +// an interface type, but the actual type conversion is checked at run +// time. + +void +Type_guard_expression::do_check_types(Gogo*) +{ + Type* expr_type = this->expr_->type(); + if (expr_type->interface_type() == NULL) + { + if (!expr_type->is_error() && !this->type_->is_error()) + this->report_error(_("type assertion only valid for interface types")); + this->set_is_error(); + } + else if (this->type_->interface_type() == NULL) + { + std::string reason; + if (!expr_type->interface_type()->implements_interface(this->type_, + &reason)) + { + if (!this->type_->is_error()) + { + if (reason.empty()) + this->report_error(_("impossible type assertion: " + "type does not implement interface")); + else + error_at(this->location(), + ("impossible type assertion: " + "type does not implement interface (%s)"), + reason.c_str()); + } + this->set_is_error(); + } + } +} + +// Return a tree for a type guard expression. + +tree +Type_guard_expression::do_get_tree(Translate_context* context) +{ + tree expr_tree = this->expr_->get_tree(context); + if (expr_tree == error_mark_node) + return error_mark_node; + if (this->type_->interface_type() != NULL) + return Expression::convert_interface_to_interface(context, this->type_, + this->expr_->type(), + expr_tree, true, + this->location()); + else + return Expression::convert_for_assignment(context, this->type_, + this->expr_->type(), expr_tree, + this->location()); +} + +// Dump ast representation for a type guard expression. + +void +Type_guard_expression::do_dump_expression(Ast_dump_context* ast_dump_context) + const +{ + this->expr_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << "."; + ast_dump_context->dump_type(this->type_); +} + +// Make a type guard expression. + +Expression* +Expression::make_type_guard(Expression* expr, Type* type, + Location location) +{ + return new Type_guard_expression(expr, type, location); +} + +// Class Heap_composite_expression. + +// When you take the address of a composite literal, it is allocated +// on the heap. This class implements that. + +class Heap_composite_expression : public Expression +{ + public: + Heap_composite_expression(Expression* expr, Location location) + : Expression(EXPRESSION_HEAP_COMPOSITE, location), + expr_(expr) + { } + + protected: + int + do_traverse(Traverse* traverse) + { return Expression::traverse(&this->expr_, traverse); } + + Type* + do_type() + { return Type::make_pointer_type(this->expr_->type()); } + + void + do_determine_type(const Type_context*) + { this->expr_->determine_type_no_context(); } + + Expression* + do_copy() + { + return Expression::make_heap_composite(this->expr_->copy(), + this->location()); + } + + tree + do_get_tree(Translate_context*); + + // We only export global objects, and the parser does not generate + // this in global scope. + void + do_export(Export*) const + { go_unreachable(); } + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The composite literal which is being put on the heap. + Expression* expr_; +}; + +// Return a tree which allocates a composite literal on the heap. + +tree +Heap_composite_expression::do_get_tree(Translate_context* context) +{ + tree expr_tree = this->expr_->get_tree(context); + if (expr_tree == error_mark_node || TREE_TYPE(expr_tree) == error_mark_node) + return error_mark_node; + tree expr_size = TYPE_SIZE_UNIT(TREE_TYPE(expr_tree)); + go_assert(TREE_CODE(expr_size) == INTEGER_CST); + tree space = context->gogo()->allocate_memory(this->expr_->type(), + expr_size, this->location()); + space = fold_convert(build_pointer_type(TREE_TYPE(expr_tree)), space); + space = save_expr(space); + tree ref = build_fold_indirect_ref_loc(this->location().gcc_location(), + space); + TREE_THIS_NOTRAP(ref) = 1; + tree ret = build2(COMPOUND_EXPR, TREE_TYPE(space), + build2(MODIFY_EXPR, void_type_node, ref, expr_tree), + space); + SET_EXPR_LOCATION(ret, this->location().gcc_location()); + return ret; +} + +// Dump ast representation for a heap composite expression. + +void +Heap_composite_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "&("; + ast_dump_context->dump_expression(this->expr_); + ast_dump_context->ostream() << ")"; +} + +// Allocate a composite literal on the heap. + +Expression* +Expression::make_heap_composite(Expression* expr, Location location) +{ + return new Heap_composite_expression(expr, location); +} + +// Class Receive_expression. + +// Return the type of a receive expression. + +Type* +Receive_expression::do_type() +{ + Channel_type* channel_type = this->channel_->type()->channel_type(); + if (channel_type == NULL) + return Type::make_error_type(); + return channel_type->element_type(); +} + +// Check types for a receive expression. + +void +Receive_expression::do_check_types(Gogo*) +{ + Type* type = this->channel_->type(); + if (type->is_error()) + { + this->set_is_error(); + return; + } + if (type->channel_type() == NULL) + { + this->report_error(_("expected channel")); + return; + } + if (!type->channel_type()->may_receive()) + { + this->report_error(_("invalid receive on send-only channel")); + return; + } +} + +// Get a tree for a receive expression. + +tree +Receive_expression::do_get_tree(Translate_context* context) +{ + Location loc = this->location(); + + Channel_type* channel_type = this->channel_->type()->channel_type(); + if (channel_type == NULL) + { + go_assert(this->channel_->type()->is_error()); + return error_mark_node; + } + + Expression* td = Expression::make_type_descriptor(channel_type, loc); + tree td_tree = td->get_tree(context); + + Type* element_type = channel_type->element_type(); + Btype* element_type_btype = element_type->get_backend(context->gogo()); + tree element_type_tree = type_to_tree(element_type_btype); + + tree channel = this->channel_->get_tree(context); + if (element_type_tree == error_mark_node || channel == error_mark_node) + return error_mark_node; + + return Gogo::receive_from_channel(element_type_tree, td_tree, channel, loc); +} + +// Dump ast representation for a receive expression. + +void +Receive_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << " <- " ; + ast_dump_context->dump_expression(channel_); +} + +// Make a receive expression. + +Receive_expression* +Expression::make_receive(Expression* channel, Location location) +{ + return new Receive_expression(channel, location); +} + +// An expression which evaluates to a pointer to the type descriptor +// of a type. + +class Type_descriptor_expression : public Expression +{ + public: + Type_descriptor_expression(Type* type, Location location) + : Expression(EXPRESSION_TYPE_DESCRIPTOR, location), + type_(type) + { } + + protected: + Type* + do_type() + { return Type::make_type_descriptor_ptr_type(); } + + bool + do_is_immutable() const + { return true; } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context* context) + { + Bexpression* ret = this->type_->type_descriptor_pointer(context->gogo(), + this->location()); + return expr_to_tree(ret); + } + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type for which this is the descriptor. + Type* type_; +}; + +// Dump ast representation for a type descriptor expression. + +void +Type_descriptor_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->dump_type(this->type_); +} + +// Make a type descriptor expression. + +Expression* +Expression::make_type_descriptor(Type* type, Location location) +{ + return new Type_descriptor_expression(type, location); +} + +// An expression which evaluates to some characteristic of a type. +// This is only used to initialize fields of a type descriptor. Using +// a new expression class is slightly inefficient but gives us a good +// separation between the frontend and the middle-end with regard to +// how types are laid out. + +class Type_info_expression : public Expression +{ + public: + Type_info_expression(Type* type, Type_info type_info) + : Expression(EXPRESSION_TYPE_INFO, Linemap::predeclared_location()), + type_(type), type_info_(type_info) + { } + + protected: + Type* + do_type(); + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context* context); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type for which we are getting information. + Type* type_; + // What information we want. + Type_info type_info_; +}; + +// The type is chosen to match what the type descriptor struct +// expects. + +Type* +Type_info_expression::do_type() +{ + switch (this->type_info_) + { + case TYPE_INFO_SIZE: + return Type::lookup_integer_type("uintptr"); + case TYPE_INFO_ALIGNMENT: + case TYPE_INFO_FIELD_ALIGNMENT: + return Type::lookup_integer_type("uint8"); + default: + go_unreachable(); + } +} + +// Return type information in GENERIC. + +tree +Type_info_expression::do_get_tree(Translate_context* context) +{ + Btype* btype = this->type_->get_backend(context->gogo()); + Gogo* gogo = context->gogo(); + size_t val; + switch (this->type_info_) + { + case TYPE_INFO_SIZE: + val = gogo->backend()->type_size(btype); + break; + case TYPE_INFO_ALIGNMENT: + val = gogo->backend()->type_alignment(btype); + break; + case TYPE_INFO_FIELD_ALIGNMENT: + val = gogo->backend()->type_field_alignment(btype); + break; + default: + go_unreachable(); + } + tree val_type_tree = type_to_tree(this->type()->get_backend(gogo)); + go_assert(val_type_tree != error_mark_node); + return build_int_cstu(val_type_tree, val); +} + +// Dump ast representation for a type info expression. + +void +Type_info_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "typeinfo("; + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << ","; + ast_dump_context->ostream() << + (this->type_info_ == TYPE_INFO_ALIGNMENT ? "alignment" + : this->type_info_ == TYPE_INFO_FIELD_ALIGNMENT ? "field alignment" + : this->type_info_ == TYPE_INFO_SIZE ? "size " + : "unknown"); + ast_dump_context->ostream() << ")"; +} + +// Make a type info expression. + +Expression* +Expression::make_type_info(Type* type, Type_info type_info) +{ + return new Type_info_expression(type, type_info); +} + +// An expression that evaluates to some characteristic of a slice. +// This is used when indexing, bound-checking, or nil checking a slice. + +class Slice_info_expression : public Expression +{ + public: + Slice_info_expression(Expression* slice, Slice_info slice_info, + Location location) + : Expression(EXPRESSION_SLICE_INFO, location), + slice_(slice), slice_info_(slice_info) + { } + + protected: + Type* + do_type(); + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { + return new Slice_info_expression(this->slice_->copy(), this->slice_info_, + this->location()); + } + + tree + do_get_tree(Translate_context* context); + + void + do_dump_expression(Ast_dump_context*) const; + + void + do_issue_nil_check() + { this->slice_->issue_nil_check(); } + + private: + // The slice for which we are getting information. + Expression* slice_; + // What information we want. + Slice_info slice_info_; +}; + +// Return the type of the slice info. + +Type* +Slice_info_expression::do_type() +{ + switch (this->slice_info_) + { + case SLICE_INFO_VALUE_POINTER: + return Type::make_pointer_type( + this->slice_->type()->array_type()->element_type()); + case SLICE_INFO_LENGTH: + case SLICE_INFO_CAPACITY: + return Type::lookup_integer_type("int"); + default: + go_unreachable(); + } +} + +// Return slice information in GENERIC. + +tree +Slice_info_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + + Bexpression* bslice = tree_to_expr(this->slice_->get_tree(context)); + Bexpression* ret; + switch (this->slice_info_) + { + case SLICE_INFO_VALUE_POINTER: + case SLICE_INFO_LENGTH: + case SLICE_INFO_CAPACITY: + ret = gogo->backend()->struct_field_expression(bslice, this->slice_info_, + this->location()); + break; + default: + go_unreachable(); + } + return expr_to_tree(ret); +} + +// Dump ast representation for a type info expression. + +void +Slice_info_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "sliceinfo("; + this->slice_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << ","; + ast_dump_context->ostream() << + (this->slice_info_ == SLICE_INFO_VALUE_POINTER ? "values" + : this->slice_info_ == SLICE_INFO_LENGTH ? "length" + : this->slice_info_ == SLICE_INFO_CAPACITY ? "capacity " + : "unknown"); + ast_dump_context->ostream() << ")"; +} + +// Make a slice info expression. + +Expression* +Expression::make_slice_info(Expression* slice, Slice_info slice_info, + Location location) +{ + return new Slice_info_expression(slice, slice_info, location); +} + + +// An expression that evaluates to some characteristic of a non-empty interface. +// This is used to access the method table or underlying object of an interface. + +class Interface_info_expression : public Expression +{ + public: + Interface_info_expression(Expression* iface, Interface_info iface_info, + Location location) + : Expression(EXPRESSION_INTERFACE_INFO, location), + iface_(iface), iface_info_(iface_info) + { } + + protected: + Type* + do_type(); + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { + return new Interface_info_expression(this->iface_->copy(), + this->iface_info_, this->location()); + } + + tree + do_get_tree(Translate_context* context); + + void + do_dump_expression(Ast_dump_context*) const; + + void + do_issue_nil_check() + { this->iface_->issue_nil_check(); } + + private: + // The interface for which we are getting information. + Expression* iface_; + // What information we want. + Interface_info iface_info_; +}; + +// Return the type of the interface info. + +Type* +Interface_info_expression::do_type() +{ + switch (this->iface_info_) + { + case INTERFACE_INFO_METHODS: + { + Location loc = this->location(); + Struct_field_list* sfl = new Struct_field_list(); + Type* pdt = Type::make_type_descriptor_ptr_type(); + sfl->push_back( + Struct_field(Typed_identifier("__type_descriptor", pdt, loc))); + + Interface_type* itype = this->iface_->type()->interface_type(); + for (Typed_identifier_list::const_iterator p = itype->methods()->begin(); + p != itype->methods()->end(); + ++p) + { + Function_type* ft = p->type()->function_type(); + go_assert(ft->receiver() == NULL); + + const Typed_identifier_list* params = ft->parameters(); + Typed_identifier_list* mparams = new Typed_identifier_list(); + if (params != NULL) + mparams->reserve(params->size() + 1); + Type* vt = Type::make_pointer_type(Type::make_void_type()); + mparams->push_back(Typed_identifier("", vt, ft->location())); + if (params != NULL) + { + for (Typed_identifier_list::const_iterator pp = params->begin(); + pp != params->end(); + ++pp) + mparams->push_back(*pp); + } + + Typed_identifier_list* mresults = (ft->results() == NULL + ? NULL + : ft->results()->copy()); + Backend_function_type* mft = + Type::make_backend_function_type(NULL, mparams, mresults, + ft->location()); + + std::string fname = Gogo::unpack_hidden_name(p->name()); + sfl->push_back(Struct_field(Typed_identifier(fname, mft, loc))); + } + + return Type::make_pointer_type(Type::make_struct_type(sfl, loc)); + } + case INTERFACE_INFO_OBJECT: + return Type::make_pointer_type(Type::make_void_type()); + default: + go_unreachable(); + } +} + +// Return interface information in GENERIC. + +tree +Interface_info_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + + Bexpression* biface = tree_to_expr(this->iface_->get_tree(context)); + Bexpression* ret; + switch (this->iface_info_) + { + case INTERFACE_INFO_METHODS: + case INTERFACE_INFO_OBJECT: + ret = gogo->backend()->struct_field_expression(biface, this->iface_info_, + this->location()); + break; + default: + go_unreachable(); + } + return expr_to_tree(ret); +} + +// Dump ast representation for an interface info expression. + +void +Interface_info_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "interfaceinfo("; + this->iface_->dump_expression(ast_dump_context); + ast_dump_context->ostream() << ","; + ast_dump_context->ostream() << + (this->iface_info_ == INTERFACE_INFO_METHODS ? "methods" + : this->iface_info_ == INTERFACE_INFO_OBJECT ? "object" + : "unknown"); + ast_dump_context->ostream() << ")"; +} + +// Make an interface info expression. + +Expression* +Expression::make_interface_info(Expression* iface, Interface_info iface_info, + Location location) +{ + return new Interface_info_expression(iface, iface_info, location); +} + +// An expression which evaluates to the offset of a field within a +// struct. This, like Type_info_expression, q.v., is only used to +// initialize fields of a type descriptor. + +class Struct_field_offset_expression : public Expression +{ + public: + Struct_field_offset_expression(Struct_type* type, const Struct_field* field) + : Expression(EXPRESSION_STRUCT_FIELD_OFFSET, + Linemap::predeclared_location()), + type_(type), field_(field) + { } + + protected: + Type* + do_type() + { return Type::lookup_integer_type("uintptr"); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context* context); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type of the struct. + Struct_type* type_; + // The field. + const Struct_field* field_; +}; + +// Return a struct field offset in GENERIC. + +tree +Struct_field_offset_expression::do_get_tree(Translate_context* context) +{ + tree type_tree = type_to_tree(this->type_->get_backend(context->gogo())); + if (type_tree == error_mark_node) + return error_mark_node; + + tree val_type_tree = type_to_tree(this->type()->get_backend(context->gogo())); + go_assert(val_type_tree != error_mark_node); + + const Struct_field_list* fields = this->type_->fields(); + tree struct_field_tree = TYPE_FIELDS(type_tree); + Struct_field_list::const_iterator p; + for (p = fields->begin(); + p != fields->end(); + ++p, struct_field_tree = DECL_CHAIN(struct_field_tree)) + { + go_assert(struct_field_tree != NULL_TREE); + if (&*p == this->field_) + break; + } + go_assert(&*p == this->field_); + + return fold_convert_loc(BUILTINS_LOCATION, val_type_tree, + byte_position(struct_field_tree)); +} + +// Dump ast representation for a struct field offset expression. + +void +Struct_field_offset_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "unsafe.Offsetof("; + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << '.'; + ast_dump_context->ostream() << + Gogo::message_name(this->field_->field_name()); + ast_dump_context->ostream() << ")"; +} + +// Make an expression for a struct field offset. + +Expression* +Expression::make_struct_field_offset(Struct_type* type, + const Struct_field* field) +{ + return new Struct_field_offset_expression(type, field); +} + +// An expression which evaluates to a pointer to the map descriptor of +// a map type. + +class Map_descriptor_expression : public Expression +{ + public: + Map_descriptor_expression(Map_type* type, Location location) + : Expression(EXPRESSION_MAP_DESCRIPTOR, location), + type_(type) + { } + + protected: + Type* + do_type() + { return Type::make_pointer_type(Map_type::make_map_descriptor_type()); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return this; } + + tree + do_get_tree(Translate_context* context) + { + Bexpression* ret = this->type_->map_descriptor_pointer(context->gogo(), + this->location()); + return expr_to_tree(ret); + } + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The type for which this is the descriptor. + Map_type* type_; +}; + +// Dump ast representation for a map descriptor expression. + +void +Map_descriptor_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "map_descriptor("; + ast_dump_context->dump_type(this->type_); + ast_dump_context->ostream() << ")"; +} + +// Make a map descriptor expression. + +Expression* +Expression::make_map_descriptor(Map_type* type, Location location) +{ + return new Map_descriptor_expression(type, location); +} + +// An expression which evaluates to the address of an unnamed label. + +class Label_addr_expression : public Expression +{ + public: + Label_addr_expression(Label* label, Location location) + : Expression(EXPRESSION_LABEL_ADDR, location), + label_(label) + { } + + protected: + Type* + do_type() + { return Type::make_pointer_type(Type::make_void_type()); } + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { return new Label_addr_expression(this->label_, this->location()); } + + tree + do_get_tree(Translate_context* context) + { + return expr_to_tree(this->label_->get_addr(context, this->location())); + } + + void + do_dump_expression(Ast_dump_context* ast_dump_context) const + { ast_dump_context->ostream() << this->label_->name(); } + + private: + // The label whose address we are taking. + Label* label_; +}; + +// Make an expression for the address of an unnamed label. + +Expression* +Expression::make_label_addr(Label* label, Location location) +{ + return new Label_addr_expression(label, location); +} + +// Conditional expressions. + +class Conditional_expression : public Expression +{ + public: + Conditional_expression(Expression* cond, Expression* then_expr, + Expression* else_expr, Location location) + : Expression(EXPRESSION_CONDITIONAL, location), + cond_(cond), then_(then_expr), else_(else_expr) + {} + + protected: + Type* + do_type(); + + void + do_determine_type(const Type_context*) + { } + + Expression* + do_copy() + { + return new Conditional_expression(this->cond_->copy(), this->then_->copy(), + this->else_->copy(), this->location()); + } + + tree + do_get_tree(Translate_context* context); + + void + do_dump_expression(Ast_dump_context*) const; + + private: + // The condition to be checked. + Expression* cond_; + // The expression to execute if the condition is true. + Expression* then_; + // The expression to execute if the condition is false. + Expression* else_; +}; + +// Return the type of the conditional expression. + +Type* +Conditional_expression::do_type() +{ + Type* result_type = Type::make_void_type(); + if (this->then_->type() == this->else_->type()) + result_type = this->then_->type(); + else if (this->then_->is_nil_expression() + || this->else_->is_nil_expression()) + result_type = (!this->then_->is_nil_expression() + ? this->then_->type() + : this->else_->type()); + return result_type; +} + +// Get the backend representation of a conditional expression. + +tree +Conditional_expression::do_get_tree(Translate_context* context) +{ + Gogo* gogo = context->gogo(); + Btype* result_btype = this->type()->get_backend(gogo); + Bexpression* cond = tree_to_expr(this->cond_->get_tree(context)); + Bexpression* then = tree_to_expr(this->then_->get_tree(context)); + Bexpression* belse = tree_to_expr(this->else_->get_tree(context)); + Bexpression* ret = + gogo->backend()->conditional_expression(result_btype, cond, then, belse, + this->location()); + return expr_to_tree(ret); +} + +// Dump ast representation of a conditional expression. + +void +Conditional_expression::do_dump_expression( + Ast_dump_context* ast_dump_context) const +{ + ast_dump_context->ostream() << "("; + ast_dump_context->dump_expression(this->cond_); + ast_dump_context->ostream() << " ? "; + ast_dump_context->dump_expression(this->then_); + ast_dump_context->ostream() << " : "; + ast_dump_context->dump_expression(this->else_); + ast_dump_context->ostream() << ") "; +} + +// Make a conditional expression. + +Expression* +Expression::make_conditional(Expression* cond, Expression* then, + Expression* else_expr, Location location) +{ + return new Conditional_expression(cond, then, else_expr, location); +} + +// Import an expression. This comes at the end in order to see the +// various class definitions. + +Expression* +Expression::import_expression(Import* imp) +{ + int c = imp->peek_char(); + if (imp->match_c_string("- ") + || imp->match_c_string("! ") + || imp->match_c_string("^ ")) + return Unary_expression::do_import(imp); + else if (c == '(') + return Binary_expression::do_import(imp); + else if (imp->match_c_string("true") + || imp->match_c_string("false")) + return Boolean_expression::do_import(imp); + else if (c == '"') + return String_expression::do_import(imp); + else if (c == '-' || (c >= '0' && c <= '9')) + { + // This handles integers, floats and complex constants. + return Integer_expression::do_import(imp); + } + else if (imp->match_c_string("nil")) + return Nil_expression::do_import(imp); + else if (imp->match_c_string("convert")) + return Type_conversion_expression::do_import(imp); + else + { + error_at(imp->location(), "import error: expected expression"); + return Expression::make_error(imp->location()); + } +} + +// Class Expression_list. + +// Traverse the list. + +int +Expression_list::traverse(Traverse* traverse) +{ + for (Expression_list::iterator p = this->begin(); + p != this->end(); + ++p) + { + if (*p != NULL) + { + if (Expression::traverse(&*p, traverse) == TRAVERSE_EXIT) + return TRAVERSE_EXIT; + } + } + return TRAVERSE_CONTINUE; +} + +// Copy the list. + +Expression_list* +Expression_list::copy() +{ + Expression_list* ret = new Expression_list(); + for (Expression_list::iterator p = this->begin(); + p != this->end(); + ++p) + { + if (*p == NULL) + ret->push_back(NULL); + else + ret->push_back((*p)->copy()); + } + return ret; +} + +// Return whether an expression list has an error expression. + +bool +Expression_list::contains_error() const +{ + for (Expression_list::const_iterator p = this->begin(); + p != this->end(); + ++p) + if (*p != NULL && (*p)->is_error_expression()) + return true; + return false; +} + +// Class Numeric_constant. + +// Destructor. + +Numeric_constant::~Numeric_constant() +{ + this->clear(); +} + +// Copy constructor. + +Numeric_constant::Numeric_constant(const Numeric_constant& a) + : classification_(a.classification_), type_(a.type_) +{ + switch (a.classification_) + { + case NC_INVALID: + break; + case NC_INT: + case NC_RUNE: + mpz_init_set(this->u_.int_val, a.u_.int_val); + break; + case NC_FLOAT: + mpfr_init_set(this->u_.float_val, a.u_.float_val, GMP_RNDN); + break; + case NC_COMPLEX: + mpfr_init_set(this->u_.complex_val.real, a.u_.complex_val.real, + GMP_RNDN); + mpfr_init_set(this->u_.complex_val.imag, a.u_.complex_val.imag, + GMP_RNDN); + break; + default: + go_unreachable(); + } +} + +// Assignment operator. + +Numeric_constant& +Numeric_constant::operator=(const Numeric_constant& a) +{ + this->clear(); + this->classification_ = a.classification_; + this->type_ = a.type_; + switch (a.classification_) + { + case NC_INVALID: + break; + case NC_INT: + case NC_RUNE: + mpz_init_set(this->u_.int_val, a.u_.int_val); + break; + case NC_FLOAT: + mpfr_init_set(this->u_.float_val, a.u_.float_val, GMP_RNDN); + break; + case NC_COMPLEX: + mpfr_init_set(this->u_.complex_val.real, a.u_.complex_val.real, + GMP_RNDN); + mpfr_init_set(this->u_.complex_val.imag, a.u_.complex_val.imag, + GMP_RNDN); + break; + default: + go_unreachable(); + } + return *this; +} + +// Clear the contents. + +void +Numeric_constant::clear() +{ + switch (this->classification_) + { + case NC_INVALID: + break; + case NC_INT: + case NC_RUNE: + mpz_clear(this->u_.int_val); + break; + case NC_FLOAT: + mpfr_clear(this->u_.float_val); + break; + case NC_COMPLEX: + mpfr_clear(this->u_.complex_val.real); + mpfr_clear(this->u_.complex_val.imag); + break; + default: + go_unreachable(); + } + this->classification_ = NC_INVALID; +} + +// Set to an unsigned long value. + +void +Numeric_constant::set_unsigned_long(Type* type, unsigned long val) +{ + this->clear(); + this->classification_ = NC_INT; + this->type_ = type; + mpz_init_set_ui(this->u_.int_val, val); +} + +// Set to an integer value. + +void +Numeric_constant::set_int(Type* type, const mpz_t val) +{ + this->clear(); + this->classification_ = NC_INT; + this->type_ = type; + mpz_init_set(this->u_.int_val, val); +} + +// Set to a rune value. + +void +Numeric_constant::set_rune(Type* type, const mpz_t val) +{ + this->clear(); + this->classification_ = NC_RUNE; + this->type_ = type; + mpz_init_set(this->u_.int_val, val); +} + +// Set to a floating point value. + +void +Numeric_constant::set_float(Type* type, const mpfr_t val) +{ + this->clear(); + this->classification_ = NC_FLOAT; + this->type_ = type; + // Numeric constants do not have negative zero values, so remove + // them here. They also don't have infinity or NaN values, but we + // should never see them here. + if (mpfr_zero_p(val)) + mpfr_init_set_ui(this->u_.float_val, 0, GMP_RNDN); + else + mpfr_init_set(this->u_.float_val, val, GMP_RNDN); +} + +// Set to a complex value. + +void +Numeric_constant::set_complex(Type* type, const mpfr_t real, const mpfr_t imag) +{ + this->clear(); + this->classification_ = NC_COMPLEX; + this->type_ = type; + mpfr_init_set(this->u_.complex_val.real, real, GMP_RNDN); + mpfr_init_set(this->u_.complex_val.imag, imag, GMP_RNDN); +} + +// Get an int value. + +void +Numeric_constant::get_int(mpz_t* val) const +{ + go_assert(this->is_int()); + mpz_init_set(*val, this->u_.int_val); +} + +// Get a rune value. + +void +Numeric_constant::get_rune(mpz_t* val) const +{ + go_assert(this->is_rune()); + mpz_init_set(*val, this->u_.int_val); +} + +// Get a floating point value. + +void +Numeric_constant::get_float(mpfr_t* val) const +{ + go_assert(this->is_float()); + mpfr_init_set(*val, this->u_.float_val, GMP_RNDN); +} + +// Get a complex value. + +void +Numeric_constant::get_complex(mpfr_t* real, mpfr_t* imag) const +{ + go_assert(this->is_complex()); + mpfr_init_set(*real, this->u_.complex_val.real, GMP_RNDN); + mpfr_init_set(*imag, this->u_.complex_val.imag, GMP_RNDN); +} + +// Express value as unsigned long if possible. + +Numeric_constant::To_unsigned_long +Numeric_constant::to_unsigned_long(unsigned long* val) const +{ + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + return this->mpz_to_unsigned_long(this->u_.int_val, val); + case NC_FLOAT: + return this->mpfr_to_unsigned_long(this->u_.float_val, val); + case NC_COMPLEX: + if (!mpfr_zero_p(this->u_.complex_val.imag)) + return NC_UL_NOTINT; + return this->mpfr_to_unsigned_long(this->u_.complex_val.real, val); + default: + go_unreachable(); + } +} + +// Express integer value as unsigned long if possible. + +Numeric_constant::To_unsigned_long +Numeric_constant::mpz_to_unsigned_long(const mpz_t ival, + unsigned long *val) const +{ + if (mpz_sgn(ival) < 0) + return NC_UL_NEGATIVE; + unsigned long ui = mpz_get_ui(ival); + if (mpz_cmp_ui(ival, ui) != 0) + return NC_UL_BIG; + *val = ui; + return NC_UL_VALID; +} + +// Express floating point value as unsigned long if possible. + +Numeric_constant::To_unsigned_long +Numeric_constant::mpfr_to_unsigned_long(const mpfr_t fval, + unsigned long *val) const +{ + if (!mpfr_integer_p(fval)) + return NC_UL_NOTINT; + mpz_t ival; + mpz_init(ival); + mpfr_get_z(ival, fval, GMP_RNDN); + To_unsigned_long ret = this->mpz_to_unsigned_long(ival, val); + mpz_clear(ival); + return ret; +} + +// Convert value to integer if possible. + +bool +Numeric_constant::to_int(mpz_t* val) const +{ + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + mpz_init_set(*val, this->u_.int_val); + return true; + case NC_FLOAT: + if (!mpfr_integer_p(this->u_.float_val)) + return false; + mpz_init(*val); + mpfr_get_z(*val, this->u_.float_val, GMP_RNDN); + return true; + case NC_COMPLEX: + if (!mpfr_zero_p(this->u_.complex_val.imag) + || !mpfr_integer_p(this->u_.complex_val.real)) + return false; + mpz_init(*val); + mpfr_get_z(*val, this->u_.complex_val.real, GMP_RNDN); + return true; + default: + go_unreachable(); + } +} + +// Convert value to floating point if possible. + +bool +Numeric_constant::to_float(mpfr_t* val) const +{ + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + mpfr_init_set_z(*val, this->u_.int_val, GMP_RNDN); + return true; + case NC_FLOAT: + mpfr_init_set(*val, this->u_.float_val, GMP_RNDN); + return true; + case NC_COMPLEX: + if (!mpfr_zero_p(this->u_.complex_val.imag)) + return false; + mpfr_init_set(*val, this->u_.complex_val.real, GMP_RNDN); + return true; + default: + go_unreachable(); + } +} + +// Convert value to complex. + +bool +Numeric_constant::to_complex(mpfr_t* vr, mpfr_t* vi) const +{ + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + mpfr_init_set_z(*vr, this->u_.int_val, GMP_RNDN); + mpfr_init_set_ui(*vi, 0, GMP_RNDN); + return true; + case NC_FLOAT: + mpfr_init_set(*vr, this->u_.float_val, GMP_RNDN); + mpfr_init_set_ui(*vi, 0, GMP_RNDN); + return true; + case NC_COMPLEX: + mpfr_init_set(*vr, this->u_.complex_val.real, GMP_RNDN); + mpfr_init_set(*vi, this->u_.complex_val.imag, GMP_RNDN); + return true; + default: + go_unreachable(); + } +} + +// Get the type. + +Type* +Numeric_constant::type() const +{ + if (this->type_ != NULL) + return this->type_; + switch (this->classification_) + { + case NC_INT: + return Type::make_abstract_integer_type(); + case NC_RUNE: + return Type::make_abstract_character_type(); + case NC_FLOAT: + return Type::make_abstract_float_type(); + case NC_COMPLEX: + return Type::make_abstract_complex_type(); + default: + go_unreachable(); + } +} + +// If the constant can be expressed in TYPE, then set the type of the +// constant to TYPE and return true. Otherwise return false, and, if +// ISSUE_ERROR is true, report an appropriate error message. + +bool +Numeric_constant::set_type(Type* type, bool issue_error, Location loc) +{ + bool ret; + if (type == NULL) + ret = true; + else if (type->integer_type() != NULL) + ret = this->check_int_type(type->integer_type(), issue_error, loc); + else if (type->float_type() != NULL) + ret = this->check_float_type(type->float_type(), issue_error, loc); + else if (type->complex_type() != NULL) + ret = this->check_complex_type(type->complex_type(), issue_error, loc); + else + go_unreachable(); + if (ret) + this->type_ = type; + return ret; +} + +// Check whether the constant can be expressed in an integer type. + +bool +Numeric_constant::check_int_type(Integer_type* type, bool issue_error, + Location location) const +{ + mpz_t val; + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + mpz_init_set(val, this->u_.int_val); + break; + + case NC_FLOAT: + if (!mpfr_integer_p(this->u_.float_val)) + { + if (issue_error) + error_at(location, "floating point constant truncated to integer"); + return false; + } + mpz_init(val); + mpfr_get_z(val, this->u_.float_val, GMP_RNDN); + break; + + case NC_COMPLEX: + if (!mpfr_integer_p(this->u_.complex_val.real) + || !mpfr_zero_p(this->u_.complex_val.imag)) + { + if (issue_error) + error_at(location, "complex constant truncated to integer"); + return false; + } + mpz_init(val); + mpfr_get_z(val, this->u_.complex_val.real, GMP_RNDN); + break; + + default: + go_unreachable(); + } + + bool ret; + if (type->is_abstract()) + ret = true; + else + { + int bits = mpz_sizeinbase(val, 2); + if (type->is_unsigned()) + { + // For an unsigned type we can only accept a nonnegative + // number, and we must be able to represents at least BITS. + ret = mpz_sgn(val) >= 0 && bits <= type->bits(); + } + else + { + // For a signed type we need an extra bit to indicate the + // sign. We have to handle the most negative integer + // specially. + ret = (bits + 1 <= type->bits() + || (bits <= type->bits() + && mpz_sgn(val) < 0 + && (mpz_scan1(val, 0) + == static_cast<unsigned long>(type->bits() - 1)) + && mpz_scan0(val, type->bits()) == ULONG_MAX)); + } + } + + if (!ret && issue_error) + error_at(location, "integer constant overflow"); + + return ret; +} + +// Check whether the constant can be expressed in a floating point +// type. + +bool +Numeric_constant::check_float_type(Float_type* type, bool issue_error, + Location location) +{ + mpfr_t val; + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + mpfr_init_set_z(val, this->u_.int_val, GMP_RNDN); + break; + + case NC_FLOAT: + mpfr_init_set(val, this->u_.float_val, GMP_RNDN); + break; + + case NC_COMPLEX: + if (!mpfr_zero_p(this->u_.complex_val.imag)) + { + if (issue_error) + error_at(location, "complex constant truncated to float"); + return false; + } + mpfr_init_set(val, this->u_.complex_val.real, GMP_RNDN); + break; + + default: + go_unreachable(); + } + + bool ret; + if (type->is_abstract()) + ret = true; + else if (mpfr_nan_p(val) || mpfr_inf_p(val) || mpfr_zero_p(val)) + { + // A NaN or Infinity always fits in the range of the type. + ret = true; + } + else + { + mp_exp_t exp = mpfr_get_exp(val); + mp_exp_t max_exp; + switch (type->bits()) + { + case 32: + max_exp = 128; + break; + case 64: + max_exp = 1024; + break; + default: + go_unreachable(); + } + + ret = exp <= max_exp; + + if (ret) + { + // Round the constant to the desired type. + mpfr_t t; + mpfr_init(t); + switch (type->bits()) + { + case 32: + mpfr_set_prec(t, 24); + break; + case 64: + mpfr_set_prec(t, 53); + break; + default: + go_unreachable(); + } + mpfr_set(t, val, GMP_RNDN); + mpfr_set(val, t, GMP_RNDN); + mpfr_clear(t); + + this->set_float(type, val); + } + } + + mpfr_clear(val); + + if (!ret && issue_error) + error_at(location, "floating point constant overflow"); + + return ret; +} + +// Check whether the constant can be expressed in a complex type. + +bool +Numeric_constant::check_complex_type(Complex_type* type, bool issue_error, + Location location) +{ + if (type->is_abstract()) + return true; + + mp_exp_t max_exp; + switch (type->bits()) + { + case 64: + max_exp = 128; + break; + case 128: + max_exp = 1024; + break; + default: + go_unreachable(); + } + + mpfr_t real; + mpfr_t imag; + switch (this->classification_) + { + case NC_INT: + case NC_RUNE: + mpfr_init_set_z(real, this->u_.int_val, GMP_RNDN); + mpfr_init_set_ui(imag, 0, GMP_RNDN); + break; + + case NC_FLOAT: + mpfr_init_set(real, this->u_.float_val, GMP_RNDN); + mpfr_init_set_ui(imag, 0, GMP_RNDN); + break; + + case NC_COMPLEX: + mpfr_init_set(real, this->u_.complex_val.real, GMP_RNDN); + mpfr_init_set(imag, this->u_.complex_val.imag, GMP_RNDN); + break; + + default: + go_unreachable(); + } + + bool ret = true; + if (!mpfr_nan_p(real) + && !mpfr_inf_p(real) + && !mpfr_zero_p(real) + && mpfr_get_exp(real) > max_exp) + { + if (issue_error) + error_at(location, "complex real part overflow"); + ret = false; + } + + if (!mpfr_nan_p(imag) + && !mpfr_inf_p(imag) + && !mpfr_zero_p(imag) + && mpfr_get_exp(imag) > max_exp) + { + if (issue_error) + error_at(location, "complex imaginary part overflow"); + ret = false; + } + + if (ret) + { + // Round the constant to the desired type. + mpfr_t t; + mpfr_init(t); + switch (type->bits()) + { + case 64: + mpfr_set_prec(t, 24); + break; + case 128: + mpfr_set_prec(t, 53); + break; + default: + go_unreachable(); + } + mpfr_set(t, real, GMP_RNDN); + mpfr_set(real, t, GMP_RNDN); + mpfr_set(t, imag, GMP_RNDN); + mpfr_set(imag, t, GMP_RNDN); + mpfr_clear(t); + + this->set_complex(type, real, imag); + } + + mpfr_clear(real); + mpfr_clear(imag); + + return ret; +} + +// Return an Expression for this value. + +Expression* +Numeric_constant::expression(Location loc) const +{ + switch (this->classification_) + { + case NC_INT: + return Expression::make_integer(&this->u_.int_val, this->type_, loc); + case NC_RUNE: + return Expression::make_character(&this->u_.int_val, this->type_, loc); + case NC_FLOAT: + return Expression::make_float(&this->u_.float_val, this->type_, loc); + case NC_COMPLEX: + return Expression::make_complex(&this->u_.complex_val.real, + &this->u_.complex_val.imag, + this->type_, loc); + default: + go_unreachable(); + } +} |