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// 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 "go-c.h"
#include "gogo.h"
#include "go-diagnostics.h"
#include "go-encode-id.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_function_body*) 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)
{
go_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 true if two expressions refer to the same variable or struct
// field. This can only be true when there are no side effects.
bool
Expression::is_same_variable(Expression* a, Expression* b)
{
if (a->classification() != b->classification())
return false;
Var_expression* av = a->var_expression();
if (av != NULL)
return av->named_object() == b->var_expression()->named_object();
Field_reference_expression* af = a->field_reference_expression();
if (af != NULL)
{
Field_reference_expression* bf = b->field_reference_expression();
return (af->field_index() == bf->field_index()
&& Expression::is_same_variable(af->expr(), bf->expr()));
}
Unary_expression* au = a->unary_expression();
if (au != NULL)
{
Unary_expression* bu = b->unary_expression();
return (au->op() == OPERATOR_MULT
&& bu->op() == OPERATOR_MULT
&& Expression::is_same_variable(au->operand(),
bu->operand()));
}
return false;
}
// Return an expression handling any conversions which must be done during
// assignment.
Expression*
Expression::convert_for_assignment(Gogo*, Type* lhs_type,
Expression* rhs, Location location)
{
Type* rhs_type = rhs->type();
if (lhs_type->is_error()
|| rhs_type->is_error()
|| rhs->is_error_expression())
return Expression::make_error(location);
bool are_identical = Type::are_identical(lhs_type, rhs_type,
(Type::COMPARE_ERRORS
| Type::COMPARE_TAGS),
NULL);
if (!are_identical && lhs_type->interface_type() != NULL)
{
if (rhs_type->interface_type() == NULL)
return Expression::convert_type_to_interface(lhs_type, rhs, location);
else
return Expression::convert_interface_to_interface(lhs_type, rhs, false,
location);
}
else if (!are_identical && rhs_type->interface_type() != NULL)
return Expression::convert_interface_to_type(lhs_type, rhs, location);
else if (lhs_type->is_slice_type() && rhs_type->is_nil_type())
{
// Assigning nil to a slice.
Expression* nil = Expression::make_nil(location);
Expression* zero = Expression::make_integer_ul(0, NULL, location);
return Expression::make_slice_value(lhs_type, nil, zero, zero, location);
}
else if (rhs_type->is_nil_type())
return Expression::make_nil(location);
else if (are_identical)
{
if (lhs_type->forwarded() != rhs_type->forwarded())
{
// Different but identical types require an explicit
// conversion. This happens with type aliases.
return Expression::make_cast(lhs_type, rhs, location);
}
// No conversion is needed.
return rhs;
}
else if (lhs_type->points_to() != NULL)
return Expression::make_unsafe_cast(lhs_type, rhs, location);
else if (lhs_type->is_numeric_type())
return Expression::make_cast(lhs_type, rhs, location);
else if ((lhs_type->struct_type() != NULL
&& rhs_type->struct_type() != NULL)
|| (lhs_type->array_type() != NULL
&& rhs_type->array_type() != NULL))
{
// This conversion must be permitted by Go, or we wouldn't have
// gotten here.
return Expression::make_unsafe_cast(lhs_type, rhs, location);
}
else
return rhs;
}
// Return an expression for a conversion from a non-interface type to an
// interface type.
Expression*
Expression::convert_type_to_interface(Type* lhs_type, Expression* rhs,
Location location)
{
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.
Type* rhs_type = rhs->type();
if (rhs_type->is_nil_type())
{
Expression* nil = Expression::make_nil(location);
return Expression::make_interface_value(lhs_type, nil, nil, location);
}
// This should have been checked already.
if (!lhs_interface_type->implements_interface(rhs_type, NULL))
{
go_assert(saw_errors());
return Expression::make_error(location);
}
// 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.
Expression* first_field;
if (lhs_is_empty)
first_field = Expression::make_type_descriptor(rhs_type, location);
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;
}
if (rhs_named_type != NULL)
first_field =
rhs_named_type->interface_method_table(lhs_interface_type,
is_pointer);
else if (rhs_struct_type != NULL)
first_field =
rhs_struct_type->interface_method_table(lhs_interface_type,
is_pointer);
else
first_field = Expression::make_nil(location);
}
Expression* obj;
if (rhs_type->points_to() != NULL)
{
// We are assigning a pointer to the interface; the interface
// holds the pointer itself.
obj = rhs;
}
else
{
// We are assigning a non-pointer value to the interface; the
// interface gets a copy of the value in the heap if it escapes.
// TODO(cmang): Associate escape state state of RHS with newly
// created OBJ.
obj = Expression::make_heap_expression(rhs, location);
}
return Expression::make_interface_value(lhs_type, first_field, obj, location);
}
// Return an expression for the type descriptor of RHS.
Expression*
Expression::get_interface_type_descriptor(Expression* rhs)
{
go_assert(rhs->type()->interface_type() != NULL);
Location location = rhs->location();
// The type descriptor is the first field of an empty interface.
if (rhs->type()->interface_type()->is_empty())
return Expression::make_interface_info(rhs, INTERFACE_INFO_TYPE_DESCRIPTOR,
location);
Expression* mtable =
Expression::make_interface_info(rhs, INTERFACE_INFO_METHODS, location);
Expression* descriptor =
Expression::make_dereference(mtable, NIL_CHECK_NOT_NEEDED, location);
descriptor = Expression::make_field_reference(descriptor, 0, location);
Expression* nil = Expression::make_nil(location);
Expression* eq =
Expression::make_binary(OPERATOR_EQEQ, mtable, nil, location);
return Expression::make_conditional(eq, nil, descriptor, location);
}
// Return an expression for the conversion of an interface type to an
// interface type.
Expression*
Expression::convert_interface_to_interface(Type *lhs_type, Expression* rhs,
bool for_type_guard,
Location location)
{
if (Type::are_identical(lhs_type, rhs->type(),
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
NULL))
return rhs;
Interface_type* lhs_interface_type = lhs_type->interface_type();
bool lhs_is_empty = lhs_interface_type->is_empty();
// 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.
// We are going to evaluate RHS multiple times.
go_assert(rhs->is_variable());
// Get the type descriptor for the right hand side. This will be
// NULL for a nil interface.
Expression* rhs_type_expr = Expression::get_interface_type_descriptor(rhs);
Expression* lhs_type_expr =
Expression::make_type_descriptor(lhs_type, location);
Expression* first_field;
if (for_type_guard)
{
// A type assertion fails when converting a nil interface.
first_field = Runtime::make_call(Runtime::ASSERTITAB, location, 2,
lhs_type_expr, rhs_type_expr);
}
else if (lhs_is_empty)
{
// A conversion to an empty interface always succeeds, and the
// first field is just the type descriptor of the object.
first_field = rhs_type_expr;
}
else
{
// A conversion to a non-empty interface may fail, but unlike a
// type assertion converting nil will always succeed.
first_field = Runtime::make_call(Runtime::REQUIREITAB, location, 2,
lhs_type_expr, rhs_type_expr);
}
// The second field is simply the object pointer.
Expression* obj =
Expression::make_interface_info(rhs, INTERFACE_INFO_OBJECT, location);
return Expression::make_interface_value(lhs_type, first_field, obj, location);
}
// Return an expression for the conversion of an interface type to a
// non-interface type.
Expression*
Expression::convert_interface_to_type(Type *lhs_type, Expression* rhs,
Location location)
{
// We are going to evaluate RHS multiple times.
go_assert(rhs->is_variable());
// 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.
Expression* lhs_type_expr = Expression::make_type_descriptor(lhs_type,
location);
Expression* rhs_descriptor =
Expression::get_interface_type_descriptor(rhs);
Type* rhs_type = rhs->type();
Expression* rhs_inter_expr = Expression::make_type_descriptor(rhs_type,
location);
Expression* check_iface = Runtime::make_call(Runtime::ASSERTI2T,
location, 3, lhs_type_expr,
rhs_descriptor, rhs_inter_expr);
// If the call succeeds, pull out the value.
Expression* obj = Expression::make_interface_info(rhs, INTERFACE_INFO_OBJECT,
location);
// 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)
{
obj = Expression::make_unsafe_cast(Type::make_pointer_type(lhs_type), obj,
location);
obj = Expression::make_dereference(obj, NIL_CHECK_NOT_NEEDED,
location);
}
return Expression::make_compound(check_iface, obj, location);
}
// Convert an expression to its backend representation. 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.
Bexpression*
Expression::get_backend(Translate_context* context)
{
// The child may have marked this expression as having an error.
if (this->classification_ == EXPRESSION_ERROR)
return context->backend()->error_expression();
return this->do_get_backend(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)
{
mpc_t cval;
if (!val->to_complex(&cval))
{
go_assert(saw_errors());
return gogo->backend()->error_expression();
}
ret = gogo->backend()->complex_constant_expression(btype, cval);
mpc_clear(cval);
}
else
go_unreachable();
return ret;
}
// Return an expression which evaluates to true if VAL, of arbitrary integer
// type, is negative or is more than the maximum value of the Go type "int".
Expression*
Expression::check_bounds(Expression* val, Location loc)
{
Type* val_type = val->type();
Type* bound_type = Type::lookup_integer_type("int");
int val_type_size;
bool val_is_unsigned = false;
if (val_type->integer_type() != NULL)
{
val_type_size = val_type->integer_type()->bits();
val_is_unsigned = val_type->integer_type()->is_unsigned();
}
else
{
if (!val_type->is_numeric_type()
|| !Type::are_convertible(bound_type, val_type, NULL))
{
go_assert(saw_errors());
return Expression::make_boolean(true, loc);
}
if (val_type->complex_type() != NULL)
val_type_size = val_type->complex_type()->bits();
else
val_type_size = val_type->float_type()->bits();
}
Expression* negative_index = Expression::make_boolean(false, loc);
Expression* index_overflows = Expression::make_boolean(false, loc);
if (!val_is_unsigned)
{
Expression* zero = Expression::make_integer_ul(0, val_type, loc);
negative_index = Expression::make_binary(OPERATOR_LT, val, zero, loc);
}
int bound_type_size = bound_type->integer_type()->bits();
if (val_type_size > bound_type_size
|| (val_type_size == bound_type_size
&& val_is_unsigned))
{
mpz_t one;
mpz_init_set_ui(one, 1UL);
// maxval = 2^(bound_type_size - 1) - 1
mpz_t maxval;
mpz_init(maxval);
mpz_mul_2exp(maxval, one, bound_type_size - 1);
mpz_sub_ui(maxval, maxval, 1);
Expression* max = Expression::make_integer_z(&maxval, val_type, loc);
mpz_clear(one);
mpz_clear(maxval);
index_overflows = Expression::make_binary(OPERATOR_GT, val, max, loc);
}
return Expression::make_binary(OPERATOR_OROR, negative_index, index_overflows,
loc);
}
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; }
Bexpression*
do_get_backend(Translate_context* context)
{ return context->backend()->error_expression(); }
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; }
Bexpression*
do_get_backend(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();
}
if (this->variable_->is_variable()
&& this->variable_->var_value()->is_in_heap())
{
Node::make_node(this)->set_encoding(Node::ESCAPE_HEAP);
Node::make_node(this->variable_)->set_encoding(Node::ESCAPE_HEAP);
}
}
// The cost to inline a variable reference. We currently only support
// references to parameters.
int
Var_expression::do_inlining_cost() const
{
if (this->variable_->is_variable())
{
if (this->variable_->var_value()->is_parameter())
return 1;
}
else if (this->variable_->is_result_variable())
return 1;
return 0x100000;
}
// Export a reference to a variable.
void
Var_expression::do_export(Export_function_body* efb) const
{
efb->write_string(Gogo::unpack_hidden_name(this->variable_->name()));
}
// Get the backend representation for a reference to a variable.
Bexpression*
Var_expression::do_get_backend(Translate_context* context)
{
Bvariable* bvar = this->variable_->get_backend_variable(context->gogo(),
context->function());
bool is_in_heap;
Location loc = this->location();
Btype* btype;
Gogo* gogo = context->gogo();
if (this->variable_->is_variable())
{
is_in_heap = this->variable_->var_value()->is_in_heap();
btype = this->variable_->var_value()->type()->get_backend(gogo);
}
else if (this->variable_->is_result_variable())
{
is_in_heap = this->variable_->result_var_value()->is_in_heap();
btype = this->variable_->result_var_value()->type()->get_backend(gogo);
}
else
go_unreachable();
Bexpression* ret =
context->backend()->var_expression(bvar, loc);
if (is_in_heap)
ret = context->backend()->indirect_expression(btype, ret, true, loc);
return 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_->message_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 Enclosed_var_expression.
int
Enclosed_var_expression::do_traverse(Traverse*)
{
return TRAVERSE_CONTINUE;
}
// Lower the reference to the enclosed variable.
Expression*
Enclosed_var_expression::do_lower(Gogo* gogo, Named_object* function,
Statement_inserter* inserter, int)
{
gogo->lower_expression(function, inserter, &this->reference_);
return this;
}
// Flatten the reference to the enclosed variable.
Expression*
Enclosed_var_expression::do_flatten(Gogo* gogo, Named_object* function,
Statement_inserter* inserter)
{
gogo->flatten_expression(function, inserter, &this->reference_);
return this;
}
void
Enclosed_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();
}
if (this->variable_->is_variable()
&& this->variable_->var_value()->is_in_heap())
Node::make_node(this->variable_)->set_encoding(Node::ESCAPE_HEAP);
}
// Ast dump for enclosed variable expression.
void
Enclosed_var_expression::do_dump_expression(Ast_dump_context* adc) const
{
adc->ostream() << this->variable_->message_name();
}
// Make a reference to a variable within an enclosing function.
Expression*
Expression::make_enclosing_var_reference(Expression* reference,
Named_object* var, Location location)
{
return new Enclosed_var_expression(reference, 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 backend expression referring to the variable.
Bexpression*
Temporary_reference_expression::do_get_backend(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->points_to() != NULL
&& stype->points_to()->is_void_type())
{
Btype* btype = this->type()->base()->get_backend(gogo);
ret = gogo->backend()->convert_expression(btype, ret, this->location());
}
return 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.
Bexpression*
Set_and_use_temporary_expression::do_get_backend(Translate_context* context)
{
Location loc = this->location();
Gogo* gogo = context->gogo();
Bvariable* bvar = this->statement_->get_backend_variable(context);
Bexpression* lvar_ref = gogo->backend()->var_expression(bvar, loc);
Named_object* fn = context->function();
go_assert(fn != NULL);
Bfunction* bfn = fn->func_value()->get_or_make_decl(gogo, fn);
Bexpression* bexpr = this->expr_->get_backend(context);
Bstatement* set = gogo->backend()->assignment_statement(bfn, lvar_ref,
bexpr, loc);
Bexpression* var_ref = gogo->backend()->var_expression(bvar, loc);
Bexpression* ret = gogo->backend()->compound_expression(set, var_ref, loc);
return ret;
}
// 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), bvar_(NULL)
{ }
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()); }
Bexpression*
do_get_backend(Translate_context*);
void
do_dump_expression(Ast_dump_context*) const;
private:
// The type of this sink variable.
Type* type_;
// The temporary variable we generate.
Bvariable* bvar_;
};
// 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.
Bexpression*
Sink_expression::do_get_backend(Translate_context* context)
{
Location loc = this->location();
Gogo* gogo = context->gogo();
if (this->bvar_ == NULL)
{
go_assert(this->type_ != NULL && !this->type_->is_sink_type());
Named_object* fn = context->function();
go_assert(fn != NULL);
Bfunction* fn_ctx = fn->func_value()->get_or_make_decl(gogo, fn);
Btype* bt = this->type_->get_backend(context->gogo());
Bstatement* decl;
this->bvar_ =
gogo->backend()->temporary_variable(fn_ctx, context->bblock(), bt, NULL,
false, loc, &decl);
Bexpression* var_ref =
gogo->backend()->var_expression(this->bvar_, loc);
var_ref = gogo->backend()->compound_expression(decl, var_ref, loc);
return var_ref;
}
return gogo->backend()->var_expression(this->bvar_, loc);
}
// 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 backend representation 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())
{
go_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 backend representation 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.
Bexpression*
Func_expression::do_get_backend(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())
{
go_error_at(this->location(),
("invalid use of special builtin function %qs; "
"must be called"),
no->message_name().c_str());
return gogo->backend()->error_expression();
}
descriptor = no->func_declaration_value()->descriptor(gogo, no);
}
else
go_unreachable();
Bexpression* bdesc = descriptor->get_backend(context);
return gogo->backend()->address_expression(bdesc, this->location());
}
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.
Bexpression *bexpr = this->closure_->get_backend(context);
// Introduce a backend type conversion, to account for any differences
// between the argument type (function descriptor, struct with a
// single field) and the closure (struct with multiple fields).
Gogo* gogo = context->gogo();
Btype *btype = this->type()->get_backend(gogo);
return gogo->backend()->convert_expression(btype, bexpr, this->location());
}
// 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)
{
Func_expression* fe = new Func_expression(function, closure, location);
// Detect references to builtin functions and set the runtime code if
// appropriate.
if (function->is_function_declaration())
fe->set_runtime_code(Runtime::name_to_code(function->name()));
return fe;
}
// 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, "fn", 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 backend representation for a function descriptor.
Bexpression*
Func_descriptor_expression::do_get_backend(Translate_context* context)
{
Named_object* no = this->fn_;
Location loc = no->location();
if (this->dvar_ != NULL)
return context->backend()->var_expression(this->dvar_, loc);
Gogo* gogo = context->gogo();
std::string var_name(gogo->function_descriptor_name(no));
bool is_descriptor = false;
if (no->is_function_declaration()
&& !no->func_declaration_value()->asm_name().empty()
&& Linemap::is_predeclared_location(no->location()))
is_descriptor = true;
// The runtime package implements some functions defined in the
// syscall package. Let the syscall package define the descriptor
// in this case.
if (gogo->compiling_runtime()
&& gogo->package_name() == "runtime"
&& no->is_function()
&& !no->func_value()->asm_name().empty()
&& no->func_value()->asm_name().compare(0, 8, "syscall.") == 0)
is_descriptor = true;
Btype* btype = this->type()->get_backend(gogo);
Bvariable* bvar;
std::string asm_name(go_selectively_encode_id(var_name));
if (no->package() != NULL || is_descriptor)
bvar = context->backend()->immutable_struct_reference(var_name, asm_name,
btype, loc);
else
{
Location bloc = Linemap::predeclared_location();
// The runtime package has hash/equality functions that are
// referenced by type descriptors outside of the runtime, so the
// function descriptors must be visible even though they are not
// exported.
bool is_exported_runtime = false;
if (gogo->compiling_runtime()
&& gogo->package_name() == "runtime"
&& (no->name().find("hash") != std::string::npos
|| no->name().find("equal") != std::string::npos))
is_exported_runtime = true;
bool is_hidden = ((no->is_function()
&& no->func_value()->enclosing() != NULL)
|| (Gogo::is_hidden_name(no->name())
&& !is_exported_runtime)
|| Gogo::is_thunk(no));
bvar = context->backend()->immutable_struct(var_name, asm_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 = init->get_backend(&bcontext);
context->backend()->immutable_struct_set_init(bvar, var_name, is_hidden,
false, btype, bloc, binit);
}
this->dvar_ = bvar;
return gogo->backend()->var_expression(bvar, loc);
}
// 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_static_initializer() 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());
}
Bexpression*
do_get_backend(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 backend representation for a reference to function code.
Bexpression*
Func_code_reference_expression::do_get_backend(Translate_context* context)
{
return Func_expression::get_code_pointer(context->gogo(), this->function_,
this->location());
}
// 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_)
go_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_)
go_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_)
go_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_expression*, Location);
protected:
bool
do_is_constant() const
{ return true; }
bool
do_is_static_initializer() const
{ return true; }
Type*
do_type();
void
do_determine_type(const Type_context*);
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(Translate_context* context)
{ return context->backend()->boolean_constant_expression(this->val_); }
int
do_inlining_cost() const
{ return 1; }
void
do_export(Export_function_body* efb) const
{ efb->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_expression* imp, Location loc)
{
if (imp->version() >= EXPORT_FORMAT_V3)
imp->require_c_string("$");
if (imp->peek_char() == 't')
{
imp->require_c_string("true");
return Expression::make_boolean(true, loc);
}
else
{
imp->require_c_string("false");
return Expression::make_boolean(false, loc);
}
}
// 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.
Bexpression*
String_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Btype* btype = Type::make_string_type()->get_backend(gogo);
Location loc = this->location();
std::vector<Bexpression*> init(2);
Bexpression* str_cst =
gogo->backend()->string_constant_expression(this->val_);
init[0] = gogo->backend()->address_expression(str_cst, loc);
Btype* int_btype = Type::lookup_integer_type("int")->get_backend(gogo);
mpz_t lenval;
mpz_init_set_ui(lenval, this->val_.length());
init[1] = gogo->backend()->integer_constant_expression(int_btype, lenval);
mpz_clear(lenval);
return gogo->backend()->constructor_expression(btype, init, loc);
}
// 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_function_body* efb) const
{
String_expression::export_string(efb, this);
}
// Import a string expression.
Expression*
String_expression::do_import(Import_expression* imp, Location loc)
{
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
{
go_error_at(imp->location(), "bad string constant");
return Expression::make_error(loc);
}
}
}
return Expression::make_string(val, loc);
}
// 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);
}
// An expression that evaluates to some characteristic of a string.
// This is used when indexing, bound-checking, or nil checking a string.
class String_info_expression : public Expression
{
public:
String_info_expression(Expression* string, String_info string_info,
Location location)
: Expression(EXPRESSION_STRING_INFO, location),
string_(string), string_info_(string_info)
{ }
protected:
Type*
do_type();
void
do_determine_type(const Type_context*)
{ go_unreachable(); }
Expression*
do_copy()
{
return new String_info_expression(this->string_->copy(), this->string_info_,
this->location());
}
Bexpression*
do_get_backend(Translate_context* context);
void
do_dump_expression(Ast_dump_context*) const;
void
do_issue_nil_check()
{ this->string_->issue_nil_check(); }
private:
// The string for which we are getting information.
Expression* string_;
// What information we want.
String_info string_info_;
};
// Return the type of the string info.
Type*
String_info_expression::do_type()
{
switch (this->string_info_)
{
case STRING_INFO_DATA:
{
Type* byte_type = Type::lookup_integer_type("uint8");
return Type::make_pointer_type(byte_type);
}
case STRING_INFO_LENGTH:
return Type::lookup_integer_type("int");
default:
go_unreachable();
}
}
// Return string information in GENERIC.
Bexpression*
String_info_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Bexpression* bstring = this->string_->get_backend(context);
switch (this->string_info_)
{
case STRING_INFO_DATA:
case STRING_INFO_LENGTH:
return gogo->backend()->struct_field_expression(bstring,
this->string_info_,
this->location());
break;
default:
go_unreachable();
}
}
// Dump ast representation for a type info expression.
void
String_info_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "stringinfo(";
this->string_->dump_expression(ast_dump_context);
ast_dump_context->ostream() << ",";
ast_dump_context->ostream() <<
(this->string_info_ == STRING_INFO_DATA ? "data"
: this->string_info_ == STRING_INFO_LENGTH ? "length"
: "unknown");
ast_dump_context->ostream() << ")";
}
// Make a string info expression.
Expression*
Expression::make_string_info(Expression* string, String_info string_info,
Location location)
{
return new String_info_expression(string, string_info, 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_expression*, Location);
// 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_is_static_initializer() 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*);
Bexpression*
do_get_backend(Translate_context*);
Expression*
do_copy()
{
if (this->is_character_constant_)
return Expression::make_character(&this->val_,
(this->type_ == NULL
? NULL
: this->type_->copy_expressions()),
this->location());
else
return Expression::make_integer_z(&this->val_,
(this->type_ == NULL
? NULL
: this->type_->copy_expressions()),
this->location());
}
int
do_inlining_cost() const
{ return 1; }
void
do_export(Export_function_body*) 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 the backend representation for an integer constant.
Bexpression*
Integer_expression::do_get_backend(Translate_context* context)
{
if (this->is_error_expression()
|| (this->type_ != NULL && this->type_->is_error_type()))
{
go_assert(saw_errors());
return context->gogo()->backend()->error_expression();
}
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())
go_error_at(this->location(),
"unknown type for large integer constant");
return context->gogo()->backend()->error_expression();
}
}
Numeric_constant nc;
nc.set_int(resolved_type, this->val_);
return Expression::backend_numeric_constant_expression(context, &nc);
}
// 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_function_body* efb) const
{
bool added_type = false;
if (this->type_ != NULL
&& !this->type_->is_abstract()
&& this->type_ != efb->type_context())
{
efb->write_c_string("$convert(");
efb->write_type(this->type_);
efb->write_c_string(", ");
added_type = true;
}
Integer_expression::export_integer(efb, this->val_);
if (this->is_character_constant_)
efb->write_c_string("'");
// A trailing space lets us reliably identify the end of the number.
efb->write_c_string(" ");
if (added_type)
efb->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_expression* imp, Location loc)
{
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
{
go_error_at(imp->location(), "bad number in import data: %qs",
num.c_str());
return Expression::make_error(loc);
}
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)
{
go_error_at(imp->location(), "bad number in import data: %qs",
real_str.c_str());
return Expression::make_error(loc);
}
}
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)
{
go_error_at(imp->location(), "bad number in import data: %qs",
imag_str.c_str());
return Expression::make_error(loc);
}
mpc_t cval;
mpc_init2(cval, mpc_precision);
mpc_set_fr_fr(cval, real, imag, MPC_RNDNN);
mpfr_clear(real);
mpfr_clear(imag);
Expression* ret = Expression::make_complex(&cval, NULL, loc);
mpc_clear(cval);
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)
{
go_error_at(imp->location(), "bad number in import data: %qs",
num.c_str());
return Expression::make_error(loc);
}
Expression* ret;
if (is_character_constant)
ret = Expression::make_character(&val, NULL, loc);
else
ret = Expression::make_integer_z(&val, NULL, loc);
mpz_clear(val);
return ret;
}
else
{
mpfr_t val;
if (mpfr_init_set_str(val, num.c_str(), 10, GMP_RNDN) != 0)
{
go_error_at(imp->location(), "bad number in import data: %qs",
num.c_str());
return Expression::make_error(loc);
}
Expression* ret = Expression::make_float(&val, NULL, loc);
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 from a multi-precision integer.
Expression*
Expression::make_integer_z(const mpz_t* val, Type* type, Location location)
{
return new Integer_expression(val, type, false, location);
}
// Build a new integer value from an unsigned long.
Expression*
Expression::make_integer_ul(unsigned long val, Type *type, Location location)
{
mpz_t zval;
mpz_init_set_ui(zval, val);
Expression* ret = Expression::make_integer_z(&zval, type, location);
mpz_clear(zval);
return ret;
}
// Build a new integer value from a signed long.
Expression*
Expression::make_integer_sl(long val, Type *type, Location location)
{
mpz_t zval;
mpz_init_set_si(zval, val);
Expression* ret = Expression::make_integer_z(&zval, type, location);
mpz_clear(zval);
return ret;
}
// Store an int64_t in an uninitialized mpz_t.
static void
set_mpz_from_int64(mpz_t* zval, int64_t val)
{
if (val >= 0)
{
unsigned long ul = static_cast<unsigned long>(val);
if (static_cast<int64_t>(ul) == val)
{
mpz_init_set_ui(*zval, ul);
return;
}
}
uint64_t uv;
if (val >= 0)
uv = static_cast<uint64_t>(val);
else
uv = static_cast<uint64_t>(- val);
unsigned long ul = uv & 0xffffffffUL;
mpz_init_set_ui(*zval, ul);
mpz_t hval;
mpz_init_set_ui(hval, static_cast<unsigned long>(uv >> 32));
mpz_mul_2exp(hval, hval, 32);
mpz_add(*zval, *zval, hval);
mpz_clear(hval);
if (val < 0)
mpz_neg(*zval, *zval);
}
// Build a new integer value from an int64_t.
Expression*
Expression::make_integer_int64(int64_t val, Type* type, Location location)
{
mpz_t zval;
set_mpz_from_int64(&zval, val);
Expression* ret = Expression::make_integer_z(&zval, type, location);
mpz_clear(zval);
return ret;
}
// 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_is_static_initializer() 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_ == NULL
? NULL
: this->type_->copy_expressions()),
this->location()); }
Bexpression*
do_get_backend(Translate_context*);
int
do_inlining_cost() const
{ return 1; }
void
do_export(Export_function_body*) 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 the backend representation for a float constant.
Bexpression*
Float_expression::do_get_backend(Translate_context* context)
{
if (this->is_error_expression()
|| (this->type_ != NULL && this->type_->is_error_type()))
{
go_assert(saw_errors());
return context->gogo()->backend()->error_expression();
}
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_);
return Expression::backend_numeric_constant_expression(context, &nc);
}
// 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_function_body* efb) const
{
bool added_type = false;
if (this->type_ != NULL
&& !this->type_->is_abstract()
&& this->type_ != efb->type_context())
{
efb->write_c_string("$convert(");
efb->write_type(this->type_);
efb->write_c_string(", ");
added_type = true;
}
Float_expression::export_float(efb, this->val_);
// A trailing space lets us reliably identify the end of the number.
efb->write_c_string(" ");
if (added_type)
efb->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 mpc_t* val, Type* type, Location location)
: Expression(EXPRESSION_COMPLEX, location),
type_(type)
{
mpc_init2(this->val_, mpc_precision);
mpc_set(this->val_, *val, MPC_RNDNN);
}
// Write VAL to string dump.
static void
export_complex(String_dump* exp, const mpc_t val);
// Write REAL/IMAG to dump context.
static void
dump_complex(Ast_dump_context* ast_dump_context, const mpc_t val);
protected:
bool
do_is_constant() const
{ return true; }
bool
do_is_static_initializer() const
{ return true; }
bool
do_numeric_constant_value(Numeric_constant* nc) const
{
nc->set_complex(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_complex(&this->val_,
(this->type_ == NULL
? NULL
: this->type_->copy_expressions()),
this->location());
}
Bexpression*
do_get_backend(Translate_context*);
int
do_inlining_cost() const
{ return 2; }
void
do_export(Export_function_body*) const;
void
do_dump_expression(Ast_dump_context*) const;
private:
// The complex value.
mpc_t val_;
// 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->is_numeric_type())
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->val_);
if (!nc.set_type(this->type_, true, this->location()))
this->set_is_error();
}
// Get the backend representation for a complex constant.
Bexpression*
Complex_expression::do_get_backend(Translate_context* context)
{
if (this->is_error_expression()
|| (this->type_ != NULL && this->type_->is_error_type()))
{
go_assert(saw_errors());
return context->gogo()->backend()->error_expression();
}
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 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->val_);
return Expression::backend_numeric_constant_expression(context, &nc);
}
// Write REAL/IMAG to export data.
void
Complex_expression::export_complex(String_dump* exp, const mpc_t val)
{
if (!mpfr_zero_p(mpc_realref(val)))
{
Float_expression::export_float(exp, mpc_realref(val));
if (mpfr_sgn(mpc_imagref(val)) >= 0)
exp->write_c_string("+");
}
Float_expression::export_float(exp, mpc_imagref(val));
exp->write_c_string("i");
}
// Export a complex number in a constant expression.
void
Complex_expression::do_export(Export_function_body* efb) const
{
bool added_type = false;
if (this->type_ != NULL
&& !this->type_->is_abstract()
&& this->type_ != efb->type_context())
{
efb->write_c_string("$convert(");
efb->write_type(this->type_);
efb->write_c_string(", ");
added_type = true;
}
Complex_expression::export_complex(efb, this->val_);
// A trailing space lets us reliably identify the end of the number.
efb->write_c_string(" ");
if (added_type)
efb->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->val_);
}
// Make a complex expression.
Expression*
Expression::make_complex(const mpc_t* val, Type* type, Location location)
{
return new Complex_expression(val, 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_is_static_initializer() 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; }
Bexpression*
do_get_backend(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_function_body* efb) const
{ this->constant_->const_value()->expr()->export_expression(efb); }
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)
{
go_error_at(this->location(),
"iota is only defined in const declarations");
iota_value = 0;
}
return Expression::make_integer_ul(iota_value, NULL, this->location());
}
// 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())
{
if (nc->type() == NULL || !nc->type()->is_error_type())
{
Location loc = this->location();
if (!this->seen_)
loc = nc->location();
go_error_at(loc, "constant refers to itself");
}
this->set_is_error();
this->type_ = Type::make_error_type();
nc->set_type(this->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;
if (ret->is_error_type())
nc->set_type(ret);
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 the backend representation for a const reference.
Bexpression*
Const_expression::do_get_backend(Translate_context* context)
{
if (this->is_error_expression()
|| (this->type_ != NULL && this->type_->is_error()))
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
// 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.
Expression* expr = this->constant_->const_value()->expr();
if (this->type_ != NULL
&& this->type_->is_numeric_type()
&& (this->constant_->const_value()->type() == NULL
|| this->constant_->const_value()->type()->is_abstract()))
{
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_backend(context);
}
}
if (this->type_ != NULL)
expr = Expression::make_cast(this->type_, expr, this->location());
return expr->get_backend(context);
}
// 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_expression*, Location);
protected:
bool
do_is_constant() const
{ return true; }
bool
do_is_static_initializer() const
{ return true; }
Type*
do_type()
{ return Type::make_nil_type(); }
void
do_determine_type(const Type_context*)
{ }
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(Translate_context* context)
{ return context->backend()->nil_pointer_expression(); }
int
do_inlining_cost() const
{ return 1; }
void
do_export(Export_function_body* efb) const
{ efb->write_c_string("$nil"); }
void
do_dump_expression(Ast_dump_context* ast_dump_context) const
{ ast_dump_context->ostream() << "nil"; }
};
// Import a nil expression.
Expression*
Nil_expression::do_import(Import_expression* imp, Location loc)
{
if (imp->version() >= EXPORT_FORMAT_V3)
imp->require_c_string("$");
imp->require_c_string("nil");
return Expression::make_nil(loc);
}
// 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;
}
// Class Type_conversion_expression.
// 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);
}
}
// According to the language specification on string conversions
// (http://golang.org/ref/spec#Conversions_to_and_from_a_string_type):
// When converting an integer into a string, the string will be a UTF-8
// representation of the integer and integers "outside the range of valid
// Unicode code points are converted to '\uFFFD'."
if (type->is_string_type())
{
Numeric_constant nc;
if (val->numeric_constant_value(&nc) && nc.is_int())
{
// An integer value doesn't fit in the Unicode code point range if it
// overflows the Go "int" type or is negative.
unsigned long ul;
if (!nc.set_type(Type::lookup_integer_type("int"), false, location)
|| nc.to_unsigned_long(&ul) == Numeric_constant::NC_UL_NEGATIVE)
return Expression::make_string("\ufffd", 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++)
{
unsigned char c = static_cast<unsigned char>(*p);
vals->push_back(Expression::make_integer_ul(c,
element_type,
location));
}
}
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)
{
go_warning_at(this->location(), 0,
"invalid UTF-8 encoding");
adv = 1;
}
p += adv;
vals->push_back(Expression::make_integer_ul(c,
element_type,
location));
}
}
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_error_type() || this->expr_->is_error_expression())
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
if (((this->type()->is_string_type()
&& this->expr_->type()->is_slice_type())
|| this->expr_->type()->interface_type() != NULL)
&& !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 whether a type conversion can be used in a constant
// initializer.
bool
Type_conversion_expression::do_is_static_initializer() const
{
Type* type = this->type_;
Type* expr_type = this->expr_->type();
if (type->interface_type() != NULL
|| expr_type->interface_type() != NULL)
return false;
if (!this->expr_->is_static_initializer())
return false;
if (Type::are_identical(type, expr_type,
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
NULL))
return true;
if (type->is_string_type() && expr_type->is_string_type())
return true;
if ((type->is_numeric_type()
|| type->is_boolean_type()
|| type->points_to() != NULL)
&& (expr_type->is_numeric_type()
|| expr_type->is_boolean_type()
|| expr_type->points_to() != NULL))
return true;
return false;
}
// 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;
}
// Determine the resulting type of the conversion.
void
Type_conversion_expression::do_determine_type(const Type_context*)
{
Type_context subcontext(this->type_, false);
this->expr_->determine_type(&subcontext);
}
// 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;
go_error_at(this->location(), "%s", reason.c_str());
this->set_is_error();
}
// Copy.
Expression*
Type_conversion_expression::do_copy()
{
return new Type_conversion_expression(this->type_->copy_expressions(),
this->expr_->copy(),
this->location());
}
// Get the backend representation for a type conversion.
Bexpression*
Type_conversion_expression::do_get_backend(Translate_context* context)
{
Type* type = this->type_;
Type* expr_type = this->expr_->type();
Gogo* gogo = context->gogo();
Btype* btype = type->get_backend(gogo);
Location loc = this->location();
if (Type::are_identical(type, expr_type,
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
NULL))
{
Bexpression* bexpr = this->expr_->get_backend(context);
return gogo->backend()->convert_expression(btype, bexpr, loc);
}
else if (type->interface_type() != NULL
|| expr_type->interface_type() != NULL)
{
Expression* conversion =
Expression::convert_for_assignment(gogo, type, this->expr_,
this->location());
return conversion->get_backend(context);
}
else if (type->is_string_type()
&& expr_type->integer_type() != NULL)
{
mpz_t intval;
Numeric_constant nc;
if (this->expr_->numeric_constant_value(&nc)
&& nc.to_int(&intval)
&& mpz_fits_ushort_p(intval))
{
std::string s;
Lex::append_char(mpz_get_ui(intval), true, &s, loc);
mpz_clear(intval);
Expression* se = Expression::make_string(s, loc);
return se->get_backend(context);
}
Expression* i2s_expr =
Runtime::make_call(Runtime::INTSTRING, loc, 2,
Expression::make_nil(loc), this->expr_);
return Expression::make_cast(type, i2s_expr, loc)->get_backend(context);
}
else if (type->is_string_type() && expr_type->is_slice_type())
{
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::SLICEBYTETOSTRING;
else
{
go_assert(e->integer_type()->is_rune());
code = Runtime::SLICERUNETOSTRING;
}
return Runtime::make_call(code, loc, 2, Expression::make_nil(loc),
this->expr_)->get_backend(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);
Runtime::Function code;
if (e->integer_type()->is_byte())
code = Runtime::STRINGTOSLICEBYTE;
else
{
go_assert(e->integer_type()->is_rune());
code = Runtime::STRINGTOSLICERUNE;
}
Expression* s2a = Runtime::make_call(code, loc, 2,
Expression::make_nil(loc),
this->expr_);
return Expression::make_unsafe_cast(type, s2a, loc)->get_backend(context);
}
else if (type->is_numeric_type())
{
go_assert(Type::are_convertible(type, expr_type, NULL));
Bexpression* bexpr = this->expr_->get_backend(context);
return gogo->backend()->convert_expression(btype, bexpr, loc);
}
else if ((type->is_unsafe_pointer_type()
&& (expr_type->points_to() != NULL
|| expr_type->integer_type()))
|| (expr_type->is_unsafe_pointer_type()
&& type->points_to() != NULL)
|| (this->may_convert_function_types_
&& type->function_type() != NULL
&& expr_type->function_type() != NULL))
{
Bexpression* bexpr = this->expr_->get_backend(context);
return gogo->backend()->convert_expression(btype, bexpr, loc);
}
else
{
Expression* conversion =
Expression::convert_for_assignment(gogo, type, this->expr_, loc);
return conversion->get_backend(context);
}
}
// Cost of inlining a type conversion.
int
Type_conversion_expression::do_inlining_cost() const
{
Type* type = this->type_;
Type* expr_type = this->expr_->type();
if (type->interface_type() != NULL || expr_type->interface_type() != NULL)
return 10;
else if (type->is_string_type() && expr_type->integer_type() != NULL)
return 10;
else if (type->is_string_type() && expr_type->is_slice_type())
return 10;
else if (type->is_slice_type() && expr_type->is_string_type())
return 10;
else
return 1;
}
// Output a type conversion in a constant expression.
void
Type_conversion_expression::do_export(Export_function_body* efb) const
{
efb->write_c_string("$convert(");
efb->write_type(this->type_);
efb->write_c_string(", ");
Type* old_context = efb->type_context();
efb->set_type_context(this->type_);
this->expr_->export_expression(efb);
efb->set_type_context(old_context);
efb->write_c_string(")");
}
// Import a type conversion or a struct construction.
Expression*
Type_conversion_expression::do_import(Import_expression* imp, Location loc)
{
imp->require_c_string("$convert(");
Type* type = imp->read_type();
imp->require_c_string(", ");
Expression* val = Expression::import_expression(imp, loc);
imp->require_c_string(")");
return Expression::make_cast(type, val, loc);
}
// 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);
}
// Class Unsafe_type_conversion_expression.
// 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;
}
// Return whether an unsafe type conversion can be used as a constant
// initializer.
bool
Unsafe_type_conversion_expression::do_is_static_initializer() const
{
Type* type = this->type_;
Type* expr_type = this->expr_->type();
if (type->interface_type() != NULL
|| expr_type->interface_type() != NULL)
return false;
if (!this->expr_->is_static_initializer())
return false;
if (Type::are_convertible(type, expr_type, NULL))
return true;
if (type->is_string_type() && expr_type->is_string_type())
return true;
if ((type->is_numeric_type()
|| type->is_boolean_type()
|| type->points_to() != NULL)
&& (expr_type->is_numeric_type()
|| expr_type->is_boolean_type()
|| expr_type->points_to() != NULL))
return true;
return false;
}
// Copy.
Expression*
Unsafe_type_conversion_expression::do_copy()
{
return new Unsafe_type_conversion_expression(this->type_->copy_expressions(),
this->expr_->copy(),
this->location());
}
// Convert to backend representation.
Bexpression*
Unsafe_type_conversion_expression::do_get_backend(Translate_context* context)
{
// We are only called for a limited number of cases.
Type* t = this->type_;
Type* et = this->expr_->type();
if (t->is_error_type()
|| this->expr_->is_error_expression()
|| et->is_error_type())
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
if (t->array_type() != NULL)
go_assert(et->array_type() != NULL
&& t->is_slice_type() == et->is_slice_type());
else if (t->struct_type() != NULL)
{
if (t->named_type() != NULL
&& et->named_type() != NULL
&& !Type::are_convertible(t, et, NULL))
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
go_assert(et->struct_type() != NULL
&& Type::are_convertible(t, et, NULL));
}
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->channel_type() != NULL
|| et->map_type() != NULL
|| et->function_type() != NULL
|| et->integer_type() != NULL
|| et->is_nil_type());
else if (et->is_unsafe_pointer_type())
go_assert(t->points_to() != NULL
|| (t->integer_type() != NULL
&& t->integer_type() == Type::lookup_integer_type("uintptr")->real_type()));
else if (t->interface_type() != NULL)
{
bool empty_iface = t->interface_type()->is_empty();
go_assert(et->interface_type() != NULL
&& et->interface_type()->is_empty() == empty_iface);
}
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
|| et->is_nil_type());
else if (t->function_type() != NULL)
go_assert(et->points_to() != NULL);
else
go_unreachable();
Gogo* gogo = context->gogo();
Btype* btype = t->get_backend(gogo);
Bexpression* bexpr = this->expr_->get_backend(context);
Location loc = this->location();
return gogo->backend()->convert_expression(btype, bexpr, loc);
}
// 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);
}
// Class Unary_expression.
// Call the address_taken method of the operand if needed. This is
// called after escape analysis but before inserting write barriers.
void
Unary_expression::check_operand_address_taken(Gogo*)
{
if (this->op_ != OPERATOR_AND)
return;
// If this->escapes_ is false at this point, then it was set to
// false by an explicit call to set_does_not_escape, and the value
// does not escape. If this->escapes_ is true, we may be able to
// set it to false based on the escape analysis pass.
if (this->escapes_)
{
Node* n = Node::make_node(this);
if ((n->encoding() & ESCAPE_MASK) == int(Node::ESCAPE_NONE))
this->escapes_ = false;
}
this->expr_->address_taken(this->escapes_);
}
// If we are taking the address of a composite literal, and the
// contents are not constant, then we want to make a heap expression
// 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_)
{
go_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())
{
go_error_at(this->location(), "invalid indirect of %<unsafe.Pointer%>");
return Expression::make_error(this->location());
}
// Check for an invalid pointer dereference. We need to do this
// here because Unary_expression::do_type will return an error type
// in this case. That can cause code to appear erroneous, and
// therefore disappear at lowering time, without any error message.
if (op == OPERATOR_MULT && expr->type()->points_to() == NULL)
{
this->report_error(_("expected 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;
bool issued_error;
if (Unary_expression::eval_constant(op, &nc, loc, &result,
&issued_error))
return result.expression(loc);
else if (issued_error)
return Expression::make_error(this->location());
}
}
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()
|| this->expr_->type()->is_error_type())
{
go_assert(saw_errors());
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);
switch (this->requires_nil_check(gogo))
{
case NIL_CHECK_ERROR_ENCOUNTERED:
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
case NIL_CHECK_NOT_NEEDED:
break;
case NIL_CHECK_NEEDED:
this->create_temp_ = true;
break;
case NIL_CHECK_DEFAULT:
go_unreachable();
}
}
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();
}
// Return whether a unary expression can be used as a constant
// initializer.
bool
Unary_expression::do_is_static_initializer() const
{
if (this->op_ == OPERATOR_MULT)
return false;
else if (this->op_ == OPERATOR_AND)
return Unary_expression::base_is_static_initializer(this->expr_);
else
return this->expr_->is_static_initializer();
}
// Return whether the address of EXPR can be used as a static
// initializer.
bool
Unary_expression::base_is_static_initializer(Expression* expr)
{
// The address of a field reference can be a static initializer if
// the base can be a static initializer.
Field_reference_expression* fre = expr->field_reference_expression();
if (fre != NULL)
return Unary_expression::base_is_static_initializer(fre->expr());
// The address of an index expression can be a static initializer if
// the base can be a static initializer and the index is constant.
Array_index_expression* aind = expr->array_index_expression();
if (aind != NULL)
return (aind->end() == NULL
&& aind->start()->is_constant()
&& Unary_expression::base_is_static_initializer(aind->array()));
// The address of a global variable can be a static initializer.
Var_expression* ve = expr->var_expression();
if (ve != NULL)
{
Named_object* no = ve->named_object();
return no->is_variable() && no->var_value()->is_global();
}
// The address of a composite literal can be used as a static
// initializer if the composite literal is itself usable as a
// static initializer.
if (expr->is_composite_literal() && expr->is_static_initializer())
return true;
// The address of a string constant can be used as a static
// initializer. This can not be written in Go itself but this is
// used when building a type descriptor.
if (expr->string_expression() != NULL)
return true;
return false;
}
// Return whether this dereference expression requires an explicit nil
// check. If we are dereferencing the pointer to a large struct
// (greater than the specified size threshold), 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.
Unary_expression::Nil_check_classification
Unary_expression::requires_nil_check(Gogo* gogo)
{
go_assert(this->op_ == OPERATOR_MULT);
go_assert(this->expr_->type()->points_to() != NULL);
if (this->issue_nil_check_ == NIL_CHECK_NEEDED)
return NIL_CHECK_NEEDED;
else if (this->issue_nil_check_ == NIL_CHECK_NOT_NEEDED)
return NIL_CHECK_NOT_NEEDED;
Type* ptype = this->expr_->type()->points_to();
int64_t type_size = -1;
if (!ptype->is_void_type())
{
bool ok = ptype->backend_type_size(gogo, &type_size);
if (!ok)
return NIL_CHECK_ERROR_ENCOUNTERED;
}
int64_t size_cutoff = gogo->nil_check_size_threshold();
if (size_cutoff == -1 || (type_size != -1 && type_size >= size_cutoff))
this->issue_nil_check_ = NIL_CHECK_NEEDED;
else
this->issue_nil_check_ = NIL_CHECK_NOT_NEEDED;
return this->issue_nil_check_;
}
// Apply unary opcode OP to UNC, setting NC. Return true if this
// could be done, false if not. On overflow, issues an error and sets
// *ISSUED_ERROR.
bool
Unary_expression::eval_constant(Operator op, const Numeric_constant* unc,
Location location, Numeric_constant* nc,
bool* issued_error)
{
*issued_error = false;
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())
{
mpc_t uval;
unc->get_complex(&uval);
mpc_t val;
mpc_init2(val, mpc_precision);
mpc_neg(val, uval, MPC_RNDNN);
nc->set_complex(unc->type(), val);
mpc_clear(uval);
mpc_clear(val);
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);
if (!nc->set_type(unc->type(), true, location))
{
*issued_error = true;
return false;
}
return true;
}
// 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;
bool issued_error;
return Unary_expression::eval_constant(this->op_, &unc, this->location(),
nc, &issued_error);
}
// 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)
this->report_error(_("expected integer"));
break;
case OPERATOR_AND:
if (!this->expr_->is_addressable())
{
if (!this->create_temp_)
{
go_error_at(this->location(), "invalid operand for unary %<&%>");
this->set_is_error();
}
}
else
this->expr_->issue_nil_check();
break;
case OPERATOR_MULT:
// Indirecting through a pointer.
if (type->points_to() == NULL)
this->report_error(_("expected pointer"));
if (type->points_to()->is_error())
this->set_is_error();
break;
default:
go_unreachable();
}
}
// Get the backend representation for a unary expression.
Bexpression*
Unary_expression::do_get_backend(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);
Bexpression* bval = sut->expression()->get_backend(context);
Named_object* fn = context->function();
go_assert(fn != NULL);
Bfunction* bfn =
fn->func_value()->get_or_make_decl(gogo, fn);
Bstatement* bassign =
gogo->backend()->assignment_statement(bfn, bvar_expr, bval, loc);
Bexpression* bvar_addr =
gogo->backend()->address_expression(bvar_expr, loc);
return gogo->backend()->compound_expression(bassign, bvar_addr, loc);
}
}
Bexpression* ret;
Bexpression* bexpr = this->expr_->get_backend(context);
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_static_initializer());
if (this->expr_->classification() == EXPRESSION_UNARY)
{
Unary_expression* ue =
static_cast<Unary_expression*>(this->expr_);
go_assert(ue->op() != OPERATOR_AND);
}
}
if (this->is_gc_root_ || this->is_slice_init_)
{
std::string var_name;
bool copy_to_heap = false;
if (this->is_gc_root_)
{
// Build a decl for a GC root variable. GC roots are mutable, so
// they cannot be represented as an immutable_struct in the
// backend.
var_name = gogo->gc_root_name();
}
else
{
// Build a decl for a slice value initializer. An immutable slice
// value initializer may have to be copied to the heap if it
// contains pointers in a non-constant context.
var_name = gogo->initializer_name();
Array_type* at = this->expr_->type()->array_type();
go_assert(at != NULL);
// 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.
copy_to_heap = (context->function() != NULL
|| context->is_const());
}
std::string asm_name(go_selectively_encode_id(var_name));
Bvariable* implicit =
gogo->backend()->implicit_variable(var_name, asm_name,
btype, true, copy_to_heap,
false, 0);
gogo->backend()->implicit_variable_set_init(implicit, var_name, btype,
true, copy_to_heap, false,
bexpr);
bexpr = gogo->backend()->var_expression(implicit, loc);
// If we are not copying a slice initializer to the heap,
// then it can be changed by the program, so if it can
// contain pointers we must register it as a GC root.
if (this->is_slice_init_
&& !copy_to_heap
&& this->expr_->type()->has_pointer())
{
Bexpression* root =
gogo->backend()->var_expression(implicit, loc);
root = gogo->backend()->address_expression(root, loc);
Type* type = Type::make_pointer_type(this->expr_->type());
gogo->add_gc_root(Expression::make_backend(root, type, loc));
}
}
else if ((this->expr_->is_composite_literal()
|| this->expr_->string_expression() != NULL)
&& this->expr_->is_static_initializer())
{
std::string var_name(gogo->initializer_name());
std::string asm_name(go_selectively_encode_id(var_name));
Bvariable* decl =
gogo->backend()->immutable_struct(var_name, asm_name,
true, false, btype, loc);
gogo->backend()->immutable_struct_set_init(decl, var_name, 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);
bool known_valid = false;
Type* ptype = this->expr_->type()->points_to();
Btype* pbtype = ptype->get_backend(gogo);
switch (this->requires_nil_check(gogo))
{
case NIL_CHECK_NOT_NEEDED:
break;
case NIL_CHECK_ERROR_ENCOUNTERED:
{
go_assert(saw_errors());
return gogo->backend()->error_expression();
}
case NIL_CHECK_NEEDED:
{
go_assert(this->expr_->is_variable());
// If we're nil-checking the result of a set-and-use-temporary
// expression, then pick out the target temp and use that
// for the final result of the conditional.
Bexpression* tbexpr = bexpr;
Bexpression* ubexpr = bexpr;
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);
ubexpr = gogo->backend()->var_expression(bvar, loc);
}
Bexpression* nil =
Expression::make_nil(loc)->get_backend(context);
Bexpression* compare =
gogo->backend()->binary_expression(OPERATOR_EQEQ, tbexpr,
nil, loc);
Bexpression* crash =
gogo->runtime_error(RUNTIME_ERROR_NIL_DEREFERENCE,
loc)->get_backend(context);
Bfunction* bfn = context->function()->func_value()->get_decl();
bexpr = gogo->backend()->conditional_expression(bfn, btype,
compare,
crash, ubexpr,
loc);
known_valid = true;
break;
}
case NIL_CHECK_DEFAULT:
go_unreachable();
}
ret = gogo->backend()->indirect_expression(pbtype, bexpr,
known_valid, loc);
}
break;
default:
go_unreachable();
}
return ret;
}
// Export a unary expression.
void
Unary_expression::do_export(Export_function_body* efb) const
{
switch (this->op_)
{
case OPERATOR_PLUS:
efb->write_c_string("+");
break;
case OPERATOR_MINUS:
efb->write_c_string("-");
break;
case OPERATOR_NOT:
efb->write_c_string("!");
break;
case OPERATOR_XOR:
efb->write_c_string("^");
break;
case OPERATOR_AND:
efb->write_c_string("&");
break;
case OPERATOR_MULT:
efb->write_c_string("*");
break;
default:
go_unreachable();
}
this->expr_->export_expression(efb);
}
// Import a unary expression.
Expression*
Unary_expression::do_import(Import_expression* imp, Location loc)
{
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;
case '&':
op = OPERATOR_AND;
break;
case '*':
op = OPERATOR_MULT;
break;
default:
go_unreachable();
}
if (imp->version() < EXPORT_FORMAT_V3)
imp->require_c_string(" ");
Expression* expr = Expression::import_expression(imp, loc);
return Expression::make_unary(op, expr, loc);
}
// 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);
}
Expression*
Expression::make_dereference(Expression* ptr,
Nil_check_classification docheck,
Location location)
{
Expression* deref = Expression::make_unary(OPERATOR_MULT, ptr, location);
if (docheck == NIL_CHECK_NEEDED)
deref->unary_expression()->set_requires_nil_check(true);
else if (docheck == NIL_CHECK_NOT_NEEDED)
deref->unary_expression()->set_requires_nil_check(false);
return deref;
}
// 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 whether this expression may be used as a static initializer.
bool
Binary_expression::do_is_static_initializer() const
{
if (!this->left_->is_static_initializer()
|| !this->right_->is_static_initializer())
return false;
// Addresses can be static initializers, but we can't implement
// arbitray binary expressions of them.
Unary_expression* lu = this->left_->unary_expression();
Unary_expression* ru = this->right_->unary_expression();
if (lu != NULL && lu->op() == OPERATOR_AND)
{
if (ru != NULL && ru->op() == OPERATOR_AND)
return this->op_ == OPERATOR_MINUS;
else
return this->op_ == OPERATOR_PLUS || this->op_ == OPERATOR_MINUS;
}
else if (ru != NULL && ru->op() == OPERATOR_AND)
return this->op_ == OPERATOR_PLUS || this->op_ == OPERATOR_MINUS;
// Other cases should resolve in the backend.
return true;
}
// 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)
{
mpc_t left_val;
if (!left_nc->to_complex(&left_val))
return false;
mpc_t right_val;
if (!right_nc->to_complex(&right_val))
{
mpc_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->complex_type() != NULL)
{
int bits = type->complex_type()->bits();
mpfr_prec_round(mpc_realref(left_val), bits / 2, GMP_RNDN);
mpfr_prec_round(mpc_imagref(left_val), bits / 2, GMP_RNDN);
mpfr_prec_round(mpc_realref(right_val), bits / 2, GMP_RNDN);
mpfr_prec_round(mpc_imagref(right_val), bits / 2, GMP_RNDN);
}
*cmp = mpc_cmp(left_val, right_val) != 0;
mpc_clear(left_val);
mpc_clear(right_val);
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, and sets *ISSUED_ERROR if it did.
bool
Binary_expression::eval_constant(Operator op, Numeric_constant* left_nc,
Numeric_constant* right_nc,
Location location, Numeric_constant* nc,
bool* issued_error)
{
*issued_error = false;
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;
if (is_shift
&& ((left_type->integer_type() == NULL
&& !left_type->is_abstract())
|| (right_type->integer_type() == NULL
&& !right_type->is_abstract())))
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);
if (!r)
*issued_error = true;
}
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);
if (mpz_sizeinbase(val, 2) > 0x100000)
{
go_error_at(location, "constant addition overflow");
nc->set_invalid();
mpz_set_ui(val, 1);
}
break;
case OPERATOR_MINUS:
mpz_sub(val, left_val, right_val);
if (mpz_sizeinbase(val, 2) > 0x100000)
{
go_error_at(location, "constant subtraction overflow");
nc->set_invalid();
mpz_set_ui(val, 1);
}
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);
if (mpz_sizeinbase(val, 2) > 0x100000)
{
go_error_at(location, "constant multiplication overflow");
nc->set_invalid();
mpz_set_ui(val, 1);
}
break;
case OPERATOR_DIV:
if (mpz_sgn(right_val) != 0)
mpz_tdiv_q(val, left_val, right_val);
else
{
go_error_at(location, "division by zero");
nc->set_invalid();
mpz_set_ui(val, 0);
}
break;
case OPERATOR_MOD:
if (mpz_sgn(right_val) != 0)
mpz_tdiv_r(val, left_val, right_val);
else
{
go_error_at(location, "division by zero");
nc->set_invalid();
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
{
go_error_at(location, "shift count overflow");
nc->set_invalid();
mpz_set_ui(val, 1);
}
break;
}
break;
case OPERATOR_RSHIFT:
{
unsigned long shift = mpz_get_ui(right_val);
if (mpz_cmp_ui(right_val, shift) != 0)
{
go_error_at(location, "shift count overflow");
nc->set_invalid();
mpz_set_ui(val, 1);
}
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
{
go_error_at(location, "division by zero");
nc->set_invalid();
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)
{
mpc_t left_val;
if (!left_nc->to_complex(&left_val))
return false;
mpc_t right_val;
if (!right_nc->to_complex(&right_val))
{
mpc_clear(left_val);
return false;
}
mpc_t val;
mpc_init2(val, mpc_precision);
bool ret = true;
switch (op)
{
case OPERATOR_PLUS:
mpc_add(val, left_val, right_val, MPC_RNDNN);
break;
case OPERATOR_MINUS:
mpc_sub(val, left_val, right_val, MPC_RNDNN);
break;
case OPERATOR_OR:
case OPERATOR_XOR:
case OPERATOR_AND:
case OPERATOR_BITCLEAR:
case OPERATOR_MOD:
case OPERATOR_LSHIFT:
case OPERATOR_RSHIFT:
mpc_set_ui(val, 0, MPC_RNDNN);
ret = false;
break;
case OPERATOR_MULT:
mpc_mul(val, left_val, right_val, MPC_RNDNN);
break;
case OPERATOR_DIV:
if (mpc_cmp_si(right_val, 0) == 0)
{
go_error_at(location, "division by zero");
nc->set_invalid();
mpc_set_ui(val, 0, MPC_RNDNN);
break;
}
mpc_div(val, left_val, right_val, MPC_RNDNN);
break;
default:
go_unreachable();
}
mpc_clear(left_val);
mpc_clear(right_val);
nc->set_complex(NULL, val);
mpc_clear(val);
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;
bool issued_error;
if (!Binary_expression::eval_constant(op, &left_nc, &right_nc,
location, &nc,
&issued_error))
{
if (issued_error)
return Expression::make_error(location);
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
&& right->type()->struct_type() != NULL)
return this->lower_struct_comparison(gogo, inserter);
else if (left->type()->array_type() != NULL
&& !left->type()->is_slice_type()
&& right->type()->array_type() != NULL
&& !right->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);
}
// Lower string concatenation to String_concat_expression, so that
// we can group sequences of string additions.
if (this->left_->type()->is_string_type() && this->op_ == OPERATOR_PLUS)
{
Expression_list* exprs;
String_concat_expression* left_sce =
this->left_->string_concat_expression();
if (left_sce != NULL)
exprs = left_sce->exprs();
else
{
exprs = new Expression_list();
exprs->push_back(this->left_);
}
String_concat_expression* right_sce =
this->right_->string_concat_expression();
if (right_sce != NULL)
exprs->append(right_sce->exprs());
else
exprs->push_back(this->right_);
return Expression::make_string_concat(exprs);
}
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,
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
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,
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
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_));
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);
Expression* zero = Expression::make_integer_ul(0, NULL, loc);
return Expression::make_binary(this->op_, call, zero, loc);
}
Expression*
Binary_expression::do_flatten(Gogo* gogo, Named_object*,
Statement_inserter* inserter)
{
Location loc = this->location();
if (this->left_->type()->is_error_type()
|| this->right_->type()->is_error_type()
|| this->left_->is_error_expression()
|| this->right_->is_error_expression())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
Temporary_statement* 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);
if (is_shift_op
|| (is_idiv_op
&& (gogo->check_divide_by_zero() || gogo->check_divide_overflow())))
{
if (!this->left_->is_variable() && !this->left_->is_constant())
{
temp = Statement::make_temporary(NULL, this->left_, loc);
inserter->insert(temp);
this->left_ = Expression::make_temporary_reference(temp, loc);
}
if (!this->right_->is_variable() && !this->right_->is_constant())
{
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;
bool issued_error;
return Binary_expression::eval_constant(this->op_, &left_nc, &right_nc,
this->location(), nc, &issued_error);
}
// 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);
// For constant expressions, the context of the result is not useful in
// determining the types of the operands. It is only legal to use abstract
// boolean, numeric, and string constants as operands where it is legal to
// use non-abstract boolean, numeric, and string constants, respectively.
// Any issues with the operation will be resolved in the check_types pass.
bool is_constant_expr = (this->left_->is_constant()
&& this->right_->is_constant());
Type_context subcontext(*context);
if (is_constant_expr && !is_shift_op)
{
subcontext.type = NULL;
subcontext.may_be_abstract = true;
}
else if (is_comparison)
{
// In a comparison, the context does not determine the types of
// the operands.
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()
|| !otype->is_boolean_type())
{
go_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))
{
go_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))
{
go_error_at(location, "%s", reason.c_str());
return false;
}
}
break;
case OPERATOR_PLUS:
case OPERATOR_PLUSEQ:
if ((!type->is_numeric_type() && !type->is_string_type())
|| (!otype->is_numeric_type() && !otype->is_string_type()))
{
go_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->is_numeric_type() || !otype->is_numeric_type())
{
go_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 || otype->integer_type() == NULL)
{
go_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_string_type())
this->report_error(_("shift count not unsigned integer"));
else 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"));
Location rloc = this->right_->location();
this->right_ = Expression::make_integer_ul(0, right_type,
rloc);
}
mpz_clear(val);
}
}
}
}
}
// Get the backend representation for a binary expression.
Bexpression*
Binary_expression::do_get_backend(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:
return Expression::comparison(context, this->type_, this->op_,
this->left_, this->right_, loc);
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;
// Fall through.
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();
}
// The only binary operation for string is +, and that should have
// been converted to a String_concat_expression in do_lower.
go_assert(!left_type->is_string_type());
// 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_backend(context);
}
Bexpression* left = this->left_->get_backend(context);
Bexpression* right = this->right_->get_backend(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);
int bits = left_type->integer_type()->bits();
Numeric_constant nc;
unsigned long ul;
if (!this->right_->numeric_constant_value(&nc)
|| nc.to_unsigned_long(&ul) != Numeric_constant::NC_UL_VALID
|| ul >= static_cast<unsigned long>(bits))
{
mpz_t bitsval;
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;
Bfunction* bfn = context->function()->func_value()->get_decl();
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(bfn,
btype,
neg_expr,
neg_one_expr,
zero_expr,
loc);
}
ret = gogo->backend()->conditional_expression(bfn, btype, compare,
ret, overflow, loc);
mpz_clear(bitsval);
}
}
// Add checks for division by zero and division overflow as needed.
if (is_idiv_op)
{
if (gogo->check_divide_by_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;
Bexpression* crash = gogo->runtime_error(errcode,
loc)->get_backend(context);
// right == 0 ? (__go_runtime_error(...), 0) : ret
Bfunction* bfn = context->function()->func_value()->get_decl();
ret = gogo->backend()->conditional_expression(bfn, btype,
check, crash,
ret, loc);
}
if (gogo->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);
Bfunction* bfn = context->function()->func_value()->get_decl();
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(bfn, btype, cmp,
one_expr, zero_expr,
loc);
else
overflow =
gogo->backend()->conditional_expression(bfn, 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 = negate_expr->get_backend(context);
}
else
overflow = zero_expr;
}
overflow = gogo->backend()->convert_expression(btype, overflow, loc);
// right == -1 ? - left : ret
ret = gogo->backend()->conditional_expression(bfn, btype,
check, overflow,
ret, loc);
}
}
mpz_clear(zero);
mpz_clear(one);
mpz_clear(neg_one);
return ret;
}
// Export a binary expression.
void
Binary_expression::do_export(Export_function_body* efb) const
{
efb->write_c_string("(");
this->left_->export_expression(efb);
switch (this->op_)
{
case OPERATOR_OROR:
efb->write_c_string(" || ");
break;
case OPERATOR_ANDAND:
efb->write_c_string(" && ");
break;
case OPERATOR_EQEQ:
efb->write_c_string(" == ");
break;
case OPERATOR_NOTEQ:
efb->write_c_string(" != ");
break;
case OPERATOR_LT:
efb->write_c_string(" < ");
break;
case OPERATOR_LE:
efb->write_c_string(" <= ");
break;
case OPERATOR_GT:
efb->write_c_string(" > ");
break;
case OPERATOR_GE:
efb->write_c_string(" >= ");
break;
case OPERATOR_PLUS:
efb->write_c_string(" + ");
break;
case OPERATOR_MINUS:
efb->write_c_string(" - ");
break;
case OPERATOR_OR:
efb->write_c_string(" | ");
break;
case OPERATOR_XOR:
efb->write_c_string(" ^ ");
break;
case OPERATOR_MULT:
efb->write_c_string(" * ");
break;
case OPERATOR_DIV:
efb->write_c_string(" / ");
break;
case OPERATOR_MOD:
efb->write_c_string(" % ");
break;
case OPERATOR_LSHIFT:
efb->write_c_string(" << ");
break;
case OPERATOR_RSHIFT:
efb->write_c_string(" >> ");
break;
case OPERATOR_AND:
efb->write_c_string(" & ");
break;
case OPERATOR_BITCLEAR:
efb->write_c_string(" &^ ");
break;
default:
go_unreachable();
}
this->right_->export_expression(efb);
efb->write_c_string(")");
}
// Import a binary expression.
Expression*
Binary_expression::do_import(Import_expression* imp, Location loc)
{
imp->require_c_string("(");
Expression* left = Expression::import_expression(imp, loc);
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
{
go_error_at(imp->location(), "unrecognized binary operator");
return Expression::make_error(loc);
}
Expression* right = Expression::import_expression(imp, loc);
imp->require_c_string(")");
return Expression::make_binary(op, left, right, loc);
}
// 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();
Expression* zexpr = Expression::make_integer_ul(0, NULL, location);
if (left_type->is_string_type() && right_type->is_string_type())
{
if (op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ)
{
left = Runtime::make_call(Runtime::EQSTRING, location, 2,
left, right);
right = Expression::make_boolean(true, location);
}
else
{
left = Runtime::make_call(Runtime::CMPSTRING, 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::EFACEVALEQ
: Runtime::IFACEVALEQ),
location, 3, left, descriptor,
pointer_arg);
go_assert(op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ);
right = Expression::make_boolean(true, location);
}
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::EFACEEQ;
else if (!left_type->interface_type()->is_empty()
&& !right_type->interface_type()->is_empty())
compare_function = Runtime::IFACEEQ;
else
{
if (left_type->interface_type()->is_empty())
{
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::IFACEEFACEEQ;
}
left = Runtime::make_call(compare_function, location, 2, left, right);
go_assert(op == OPERATOR_EQEQ || op == OPERATOR_NOTEQ);
right = Expression::make_boolean(true, location);
}
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();
bool is_lvalue = false;
left = at->get_value_pointer(context->gogo(), left, is_lvalue);
}
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 = left->get_backend(context);
Bexpression* right_bexpr = right->get_backend(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 String_concat_expression.
bool
String_concat_expression::do_is_constant() const
{
for (Expression_list::const_iterator pe = this->exprs_->begin();
pe != this->exprs_->end();
++pe)
{
if (!(*pe)->is_constant())
return false;
}
return true;
}
bool
String_concat_expression::do_is_static_initializer() const
{
for (Expression_list::const_iterator pe = this->exprs_->begin();
pe != this->exprs_->end();
++pe)
{
if (!(*pe)->is_static_initializer())
return false;
}
return true;
}
Type*
String_concat_expression::do_type()
{
Type* t = this->exprs_->front()->type();
Expression_list::iterator pe = this->exprs_->begin();
++pe;
for (; pe != this->exprs_->end(); ++pe)
{
Type* t1;
if (!Binary_expression::operation_type(OPERATOR_PLUS, t,
(*pe)->type(),
&t1))
return Type::make_error_type();
t = t1;
}
return t;
}
void
String_concat_expression::do_determine_type(const Type_context* context)
{
Type_context subcontext(*context);
for (Expression_list::iterator pe = this->exprs_->begin();
pe != this->exprs_->end();
++pe)
{
Type* t = (*pe)->type();
if (!t->is_abstract())
{
subcontext.type = t;
break;
}
}
if (subcontext.type == NULL)
subcontext.type = this->exprs_->front()->type();
for (Expression_list::iterator pe = this->exprs_->begin();
pe != this->exprs_->end();
++pe)
(*pe)->determine_type(&subcontext);
}
void
String_concat_expression::do_check_types(Gogo*)
{
if (this->is_error_expression())
return;
Type* t = this->exprs_->front()->type();
if (t->is_error())
{
this->set_is_error();
return;
}
Expression_list::iterator pe = this->exprs_->begin();
++pe;
for (; pe != this->exprs_->end(); ++pe)
{
Type* t1 = (*pe)->type();
if (!Type::are_compatible_for_binop(t, t1))
{
this->report_error("incompatible types in binary expression");
return;
}
if (!Binary_expression::check_operator_type(OPERATOR_PLUS, t, t1,
this->location()))
{
this->set_is_error();
return;
}
}
}
Expression*
String_concat_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter*)
{
if (this->is_error_expression())
return this;
Location loc = this->location();
Type* type = this->type();
Expression* nil_arg = Expression::make_nil(loc);
Expression* call;
switch (this->exprs_->size())
{
case 0: case 1:
go_unreachable();
case 2: case 3: case 4: case 5:
{
Expression* len = Expression::make_integer_ul(this->exprs_->size(),
NULL, loc);
Array_type* arg_type = Type::make_array_type(type, len);
arg_type->set_is_array_incomparable();
Expression* arg =
Expression::make_array_composite_literal(arg_type, this->exprs_,
loc);
Runtime::Function code;
switch (this->exprs_->size())
{
default:
go_unreachable();
case 2:
code = Runtime::CONCATSTRING2;
break;
case 3:
code = Runtime::CONCATSTRING3;
break;
case 4:
code = Runtime::CONCATSTRING4;
break;
case 5:
code = Runtime::CONCATSTRING5;
break;
}
call = Runtime::make_call(code, loc, 2, nil_arg, arg);
}
break;
default:
{
Type* arg_type = Type::make_array_type(type, NULL);
Slice_construction_expression* sce =
Expression::make_slice_composite_literal(arg_type, this->exprs_,
loc);
sce->set_storage_does_not_escape();
call = Runtime::make_call(Runtime::CONCATSTRINGS, loc, 2, nil_arg,
sce);
}
break;
}
return Expression::make_cast(type, call, loc);
}
void
String_concat_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "concat(";
ast_dump_context->dump_expression_list(this->exprs_, false);
ast_dump_context->ostream() << ")";
}
Expression*
Expression::make_string_concat(Expression_list* exprs)
{
return new String_concat_expression(exprs);
}
// Class Bound_method_expression.
// Traversal.
int
Bound_method_expression::do_traverse(Traverse* traverse)
{
return Expression::traverse(&this->expr_, traverse);
}
// 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, Type::COMPARE_TAGS, 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", vt, loc)));
sfl->push_back(Struct_field(Typed_identifier("val",
orig_fntype->receiver()->type(),
loc)));
Struct_type* st = Type::make_struct_type(sfl, loc);
st->set_is_struct_incomparable();
Type* closure_type = Type::make_pointer_type(st);
Function_type* new_fntype = orig_fntype->copy_with_names();
std::string thunk_name = gogo->thunk_name();
Named_object* new_no = gogo->start_function(thunk_name, new_fntype,
false, loc);
Variable* cvar = new Variable(closure_type, NULL, false, false, false, loc);
cvar->set_is_used();
cvar->set_is_closure();
Named_object* cp = Named_object::make_variable("$closure" + thunk_name,
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_dereference(arg, NIL_CHECK_NOT_NEEDED, 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_dereference(*ref, Expression::NIL_CHECK_DEFAULT,
loc);
go_assert((*ref)->type()->struct_type() == stype);
}
*ref = Expression::make_field_reference(*ref, field_indexes->field_index,
loc);
return cond;
}
// Flatten a method value into a struct with nil checks. We can't do
// this in the lowering phase, because if the method value is called
// directly we don't need a thunk. That case will have been handled
// by Call_expression::do_lower, so if we get here then we do need a
// thunk.
Expression*
Bound_method_expression::do_flatten(Gogo* gogo, Named_object*,
Statement_inserter* inserter)
{
Location loc = this->location();
Named_object* thunk = Bound_method_expression::create_thunk(gogo,
this->method_,
this->function_);
if (thunk->is_erroneous())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
// Force the expression into a variable. This is only necessary if
// we are going to do nil checks below, but it's easy enough to
// always do it.
Expression* expr = this->expr_;
if (!expr->is_variable())
{
Temporary_statement* etemp = Statement::make_temporary(NULL, expr, loc);
inserter->insert(etemp);
expr = Expression::make_temporary_reference(etemp, loc);
}
// 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 = expr;
if (fntype->receiver()->type()->points_to() == NULL
&& val->type()->points_to() != NULL)
val = Expression::make_dereference(val, NIL_CHECK_DEFAULT, 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",
thunk->func_value()->type(),
loc)));
fields->push_back(Struct_field(Typed_identifier("val", val->type(), loc)));
Struct_type* st = Type::make_struct_type(fields, loc);
st->set_is_struct_incomparable();
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_expression(ret, loc);
Node* n = Node::make_node(this);
if ((n->encoding() & ESCAPE_MASK) == Node::ESCAPE_NONE)
ret->heap_expression()->set_allocate_on_stack();
else if (gogo->compiling_runtime() && gogo->package_name() == "runtime")
go_error_at(loc, "%s escapes to heap, not allowed in runtime",
n->ast_format(gogo).c_str());
// If necessary, check whether the expression or any embedded
// pointers are nil.
Expression* nil_check = NULL;
if (this->method_->field_indexes() != NULL)
{
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)
{
Expression* crash = gogo->runtime_error(RUNTIME_ERROR_NIL_DEREFERENCE,
loc);
// Fix the type of the conditional expression by pretending to
// evaluate to RET either way through the conditional.
crash = Expression::make_compound(crash, ret, loc);
ret = Expression::make_conditional(nil_check, crash, ret, loc);
}
// RET is a pointer to a struct, but we want a function type.
ret = Expression::make_unsafe_cast(this->type(), ret, loc);
return ret;
}
// 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.
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),
recover_arg_is_set_(false)
{
Func_expression* fnexp = this->fn()->func_expression();
if (fnexp == NULL)
{
this->code_ = BUILTIN_INVALID;
return;
}
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);
this->recover_arg_is_set_ = true;
}
// 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*, Named_object* function,
Statement_inserter* inserter, int)
{
if (this->is_error_expression())
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())
{
go_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(inserter);
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_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_type_descriptor(mt, loc);
Expression* e2 = Expression::make_temporary_reference(map_temp,
loc);
Expression* e3 = Expression::make_temporary_reference(key_temp,
loc);
// If the call to delete is deferred, and is in a loop,
// then the loop will only have a single instance of the
// temporary variable. Passing the address of the
// temporary variable here means that the deferred call
// will see the last value in the loop, not the current
// value. So for this unusual case copy the value into
// the heap.
if (!this->is_deferred())
e3 = Expression::make_unary(OPERATOR_AND, e3, loc);
else
{
Expression* a = Expression::make_allocation(mt->key_type(),
loc);
Temporary_statement* atemp =
Statement::make_temporary(NULL, a, loc);
inserter->insert(atemp);
a = Expression::make_temporary_reference(atemp, loc);
a = Expression::make_dereference(a, NIL_CHECK_NOT_NEEDED, loc);
Statement* s = Statement::make_assignment(a, e3, loc);
inserter->insert(s);
e3 = Expression::make_temporary_reference(atemp, loc);
}
return Runtime::make_call(Runtime::MAPDELETE, this->location(),
3, e1, e2, e3);
}
}
break;
case BUILTIN_PRINT:
case BUILTIN_PRINTLN:
// Force all the arguments into temporary variables, so that we
// don't try to evaluate something while holding the print lock.
if (this->args() == NULL)
break;
for (Expression_list::iterator pa = this->args()->begin();
pa != this->args()->end();
++pa)
{
if (!(*pa)->is_variable() && !(*pa)->is_constant())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, *pa, loc);
inserter->insert(temp);
*pa = Expression::make_temporary_reference(temp, loc);
}
}
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* gogo, Named_object* function,
Statement_inserter* inserter)
{
Location loc = this->location();
switch (this->code_)
{
default:
break;
case BUILTIN_APPEND:
return this->flatten_append(gogo, function, inserter, NULL, NULL);
case BUILTIN_COPY:
{
Type* at = this->args()->front()->type();
for (Expression_list::iterator pa = this->args()->begin();
pa != this->args()->end();
++pa)
{
if ((*pa)->is_nil_expression())
{
Expression* nil = Expression::make_nil(loc);
Expression* zero = Expression::make_integer_ul(0, NULL, loc);
*pa = Expression::make_slice_value(at, nil, zero, zero, loc);
}
if (!(*pa)->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, *pa, loc);
inserter->insert(temp);
*pa = Expression::make_temporary_reference(temp, loc);
}
}
}
break;
case BUILTIN_PANIC:
for (Expression_list::iterator pa = this->args()->begin();
pa != this->args()->end();
++pa)
{
if (!(*pa)->is_variable() && (*pa)->type()->interface_type() != NULL)
{
Temporary_statement* temp =
Statement::make_temporary(NULL, *pa, loc);
inserter->insert(temp);
*pa = Expression::make_temporary_reference(temp, loc);
}
}
break;
case BUILTIN_LEN:
case BUILTIN_CAP:
{
Expression_list::iterator pa = this->args()->begin();
if (!(*pa)->is_variable()
&& ((*pa)->type()->map_type() != NULL
|| (*pa)->type()->channel_type() != NULL))
{
Temporary_statement* temp =
Statement::make_temporary(NULL, *pa, loc);
inserter->insert(temp);
*pa = Expression::make_temporary_reference(temp, loc);
}
}
break;
}
return this;
}
// Lower a make expression.
Expression*
Builtin_call_expression::lower_make(Statement_inserter* inserter)
{
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())
{
go_error_at(first_arg->location(), "expected type");
this->set_is_error();
return Expression::make_error(this->location());
}
Type* type = first_arg->type();
if (!type->in_heap())
go_error_at(first_arg->location(),
"can't make slice of go:notinheap 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());
}
Type_context int_context(Type::lookup_integer_type("int"), false);
++parg;
Expression* len_arg;
bool len_small = false;
if (parg == args->end())
{
if (is_slice)
{
this->report_error(_("length required when allocating a slice"));
return Expression::make_error(this->location());
}
len_arg = Expression::make_integer_ul(0, NULL, loc);
len_small = true;
}
else
{
len_arg = *parg;
len_arg->determine_type(&int_context);
if (len_arg->type()->integer_type() == NULL)
{
go_error_at(len_arg->location(), "non-integer len argument in make");
return Expression::make_error(this->location());
}
if (!this->check_int_value(len_arg, true, &len_small))
return Expression::make_error(this->location());
++parg;
}
Expression* cap_arg = NULL;
bool cap_small = false;
Numeric_constant nclen;
Numeric_constant nccap;
unsigned long vlen;
unsigned long vcap;
if (is_slice && parg != args->end())
{
cap_arg = *parg;
cap_arg->determine_type(&int_context);
if (cap_arg->type()->integer_type() == NULL)
{
go_error_at(cap_arg->location(), "non-integer cap argument in make");
return Expression::make_error(this->location());
}
if (!this->check_int_value(cap_arg, false, &cap_small))
return Expression::make_error(this->location());
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());
}
++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* call;
if (is_slice)
{
Temporary_statement* len_temp = NULL;
if (!len_arg->is_constant())
{
len_temp = Statement::make_temporary(NULL, len_arg, loc);
inserter->insert(len_temp);
len_arg = Expression::make_temporary_reference(len_temp, loc);
}
if (cap_arg == NULL)
{
cap_small = len_small;
if (len_temp == NULL)
cap_arg = len_arg->copy();
else
cap_arg = Expression::make_temporary_reference(len_temp, loc);
}
else if (!cap_arg->is_constant())
{
Temporary_statement* cap_temp = Statement::make_temporary(NULL,
cap_arg,
loc);
inserter->insert(cap_temp);
cap_arg = Expression::make_temporary_reference(cap_temp, loc);
}
Type* et = type->array_type()->element_type();
Expression* type_arg = Expression::make_type_descriptor(et, type_loc);
Runtime::Function code = Runtime::MAKESLICE;
if (!len_small || !cap_small)
code = Runtime::MAKESLICE64;
Expression* mem = Runtime::make_call(code, loc, 3, type_arg, len_arg,
cap_arg);
mem = Expression::make_unsafe_cast(Type::make_pointer_type(et), mem,
loc);
Type* int_type = Type::lookup_integer_type("int");
len_arg = Expression::make_cast(int_type, len_arg->copy(), loc);
cap_arg = Expression::make_cast(int_type, cap_arg->copy(), loc);
call = Expression::make_slice_value(type, mem, len_arg, cap_arg, loc);
}
else if (is_map)
{
Expression* type_arg = Expression::make_type_descriptor(type, type_loc);
if (!len_small)
call = Runtime::make_call(Runtime::MAKEMAP64, loc, 3, type_arg,
len_arg,
Expression::make_nil(loc));
else
{
Numeric_constant nclen;
unsigned long vlen;
if (len_arg->numeric_constant_value(&nclen)
&& nclen.to_unsigned_long(&vlen) == Numeric_constant::NC_UL_VALID
&& vlen <= Map_type::bucket_size)
call = Runtime::make_call(Runtime::MAKEMAP_SMALL, loc, 0);
else
call = Runtime::make_call(Runtime::MAKEMAP, loc, 3, type_arg,
len_arg,
Expression::make_nil(loc));
}
}
else if (is_chan)
{
Expression* type_arg = Expression::make_type_descriptor(type, type_loc);
Runtime::Function code = Runtime::MAKECHAN;
if (!len_small)
code = Runtime::MAKECHAN64;
call = Runtime::make_call(code, loc, 2, type_arg, len_arg);
}
else
go_unreachable();
return Expression::make_unsafe_cast(type, call, loc);
}
// Flatten a call to the predeclared append function. We do this in
// the flatten phase, not the lowering phase, so that we run after
// type checking and after order_evaluations. If ASSIGN_LHS is not
// NULL, this append is the right-hand-side of an assignment and
// ASSIGN_LHS is the left-hand-side; in that case, set LHS directly
// rather than returning a slice. This lets us omit a write barrier
// in common cases like a = append(a, ...) when the slice does not
// need to grow. ENCLOSING is not NULL iff ASSIGN_LHS is not NULL.
Expression*
Builtin_call_expression::flatten_append(Gogo* gogo, Named_object* function,
Statement_inserter* inserter,
Expression* assign_lhs,
Block* enclosing)
{
if (this->is_error_expression())
return this;
Location loc = this->location();
const Expression_list* args = this->args();
go_assert(args != NULL && !args->empty());
Type* slice_type = args->front()->type();
go_assert(slice_type->is_slice_type());
Type* element_type = slice_type->array_type()->element_type();
if (args->size() == 1)
{
// append(s) evaluates to s.
if (assign_lhs != NULL)
return NULL;
return args->front();
}
Type* int_type = Type::lookup_integer_type("int");
Type* uint_type = Type::lookup_integer_type("uint");
// Implementing
// append(s1, s2...)
// or
// append(s1, a1, a2, a3, ...)
// s1tmp := s1
Temporary_statement* s1tmp = Statement::make_temporary(NULL, args->front(),
loc);
inserter->insert(s1tmp);
// l1tmp := len(s1tmp)
Named_object* lenfn = gogo->lookup_global("len");
Expression* lenref = Expression::make_func_reference(lenfn, NULL, loc);
Expression_list* call_args = new Expression_list();
call_args->push_back(Expression::make_temporary_reference(s1tmp, loc));
Expression* len = Expression::make_call(lenref, call_args, false, loc);
gogo->lower_expression(function, inserter, &len);
gogo->flatten_expression(function, inserter, &len);
Temporary_statement* l1tmp = Statement::make_temporary(int_type, len, loc);
inserter->insert(l1tmp);
Temporary_statement* s2tmp = NULL;
Temporary_statement* l2tmp = NULL;
Expression_list* add = NULL;
Expression* len2;
if (this->is_varargs())
{
go_assert(args->size() == 2);
// s2tmp := s2
s2tmp = Statement::make_temporary(NULL, args->back(), loc);
inserter->insert(s2tmp);
// l2tmp := len(s2tmp)
lenref = Expression::make_func_reference(lenfn, NULL, loc);
call_args = new Expression_list();
call_args->push_back(Expression::make_temporary_reference(s2tmp, loc));
len = Expression::make_call(lenref, call_args, false, loc);
gogo->lower_expression(function, inserter, &len);
gogo->flatten_expression(function, inserter, &len);
l2tmp = Statement::make_temporary(int_type, len, loc);
inserter->insert(l2tmp);
// len2 = l2tmp
len2 = Expression::make_temporary_reference(l2tmp, loc);
}
else
{
// We have to ensure that all the arguments are in variables
// now, because otherwise if one of them is an index expression
// into the current slice we could overwrite it before we fetch
// it.
add = new Expression_list();
Expression_list::const_iterator pa = args->begin();
for (++pa; pa != args->end(); ++pa)
{
if ((*pa)->is_variable())
add->push_back(*pa);
else
{
Temporary_statement* tmp = Statement::make_temporary(NULL, *pa,
loc);
inserter->insert(tmp);
add->push_back(Expression::make_temporary_reference(tmp, loc));
}
}
// len2 = len(add)
len2 = Expression::make_integer_ul(add->size(), int_type, loc);
}
// ntmp := l1tmp + len2
Expression* ref = Expression::make_temporary_reference(l1tmp, loc);
Expression* sum = Expression::make_binary(OPERATOR_PLUS, ref, len2, loc);
gogo->lower_expression(function, inserter, &sum);
gogo->flatten_expression(function, inserter, &sum);
Temporary_statement* ntmp = Statement::make_temporary(int_type, sum, loc);
inserter->insert(ntmp);
// s1tmp = uint(ntmp) > uint(cap(s1tmp)) ?
// growslice(type, s1tmp, ntmp) :
// s1tmp[:ntmp]
// Using uint here means that if the computation of ntmp overflowed,
// we will call growslice which will panic.
Expression* left = Expression::make_temporary_reference(ntmp, loc);
left = Expression::make_cast(uint_type, left, loc);
Named_object* capfn = gogo->lookup_global("cap");
Expression* capref = Expression::make_func_reference(capfn, NULL, loc);
call_args = new Expression_list();
call_args->push_back(Expression::make_temporary_reference(s1tmp, loc));
Expression* right = Expression::make_call(capref, call_args, false, loc);
right = Expression::make_cast(uint_type, right, loc);
Expression* cond = Expression::make_binary(OPERATOR_GT, left, right, loc);
Expression* a1 = Expression::make_type_descriptor(element_type, loc);
Expression* a2 = Expression::make_temporary_reference(s1tmp, loc);
Expression* a3 = Expression::make_temporary_reference(ntmp, loc);
Expression* call = Runtime::make_call(Runtime::GROWSLICE, loc, 3,
a1, a2, a3);
call = Expression::make_unsafe_cast(slice_type, call, loc);
ref = Expression::make_temporary_reference(s1tmp, loc);
Expression* zero = Expression::make_integer_ul(0, int_type, loc);
Expression* ref2 = Expression::make_temporary_reference(ntmp, loc);
ref = Expression::make_array_index(ref, zero, ref2, NULL, loc);
ref->array_index_expression()->set_needs_bounds_check(false);
if (assign_lhs == NULL)
{
Expression* rhs = Expression::make_conditional(cond, call, ref, loc);
gogo->lower_expression(function, inserter, &rhs);
gogo->flatten_expression(function, inserter, &rhs);
ref = Expression::make_temporary_reference(s1tmp, loc);
Statement* assign = Statement::make_assignment(ref, rhs, loc);
inserter->insert(assign);
}
else
{
gogo->lower_expression(function, inserter, &cond);
gogo->flatten_expression(function, inserter, &cond);
gogo->lower_expression(function, inserter, &call);
gogo->flatten_expression(function, inserter, &call);
gogo->lower_expression(function, inserter, &ref);
gogo->flatten_expression(function, inserter, &ref);
Block* then_block = new Block(enclosing, loc);
Assignment_statement* assign =
Statement::make_assignment(assign_lhs, call, loc);
then_block->add_statement(assign);
Block* else_block = new Block(enclosing, loc);
assign = Statement::make_assignment(assign_lhs->copy(), ref, loc);
// This assignment will not change the pointer value, so it does
// not need a write barrier.
assign->set_omit_write_barrier();
else_block->add_statement(assign);
Statement* s = Statement::make_if_statement(cond, then_block,
else_block, loc);
inserter->insert(s);
ref = Expression::make_temporary_reference(s1tmp, loc);
assign = Statement::make_assignment(ref, assign_lhs->copy(), loc);
inserter->insert(assign);
}
if (this->is_varargs())
{
// copy(s1tmp[l1tmp:], s2tmp)
a1 = Expression::make_temporary_reference(s1tmp, loc);
ref = Expression::make_temporary_reference(l1tmp, loc);
Expression* nil = Expression::make_nil(loc);
a1 = Expression::make_array_index(a1, ref, nil, NULL, loc);
a1->array_index_expression()->set_needs_bounds_check(false);
a2 = Expression::make_temporary_reference(s2tmp, loc);
Named_object* copyfn = gogo->lookup_global("copy");
Expression* copyref = Expression::make_func_reference(copyfn, NULL, loc);
call_args = new Expression_list();
call_args->push_back(a1);
call_args->push_back(a2);
call = Expression::make_call(copyref, call_args, false, loc);
gogo->lower_expression(function, inserter, &call);
gogo->flatten_expression(function, inserter, &call);
inserter->insert(Statement::make_statement(call, false));
}
else
{
// For each argument:
// s1tmp[l1tmp+i] = a
unsigned long i = 0;
for (Expression_list::const_iterator pa = add->begin();
pa != add->end();
++pa, ++i)
{
ref = Expression::make_temporary_reference(s1tmp, loc);
ref2 = Expression::make_temporary_reference(l1tmp, loc);
Expression* off = Expression::make_integer_ul(i, int_type, loc);
ref2 = Expression::make_binary(OPERATOR_PLUS, ref2, off, loc);
Expression* lhs = Expression::make_array_index(ref, ref2, NULL,
NULL, loc);
lhs->array_index_expression()->set_needs_bounds_check(false);
gogo->lower_expression(function, inserter, &lhs);
gogo->flatten_expression(function, inserter, &lhs);
// The flatten pass runs after the write barrier pass, so we
// need to insert a write barrier here if necessary.
// However, if ASSIGN_LHS is not NULL, we have been called
// directly before the write barrier pass.
Statement* assign;
if (assign_lhs != NULL
|| !gogo->assign_needs_write_barrier(lhs))
assign = Statement::make_assignment(lhs, *pa, loc);
else
{
Function* f = function == NULL ? NULL : function->func_value();
assign = gogo->assign_with_write_barrier(f, NULL, inserter,
lhs, *pa, loc);
}
inserter->insert(assign);
}
}
if (assign_lhs != NULL)
return NULL;
return Expression::make_temporary_reference(s1tmp, 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. Set *SMALL if the value is known to fit in type "int".
bool
Builtin_call_expression::check_int_value(Expression* e, bool is_length,
bool *small)
{
*small = false;
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:
go_error_at(e->location(), "non-integer %s argument to make",
is_length ? "len" : "cap");
return false;
case Numeric_constant::NC_UL_NEGATIVE:
go_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())
{
go_error_at(e->location(), "%s argument too large for make",
is_length ? "len" : "cap");
return false;
}
*small = true;
return true;
}
if (e->type()->integer_type() != NULL)
{
int ebits = e->type()->integer_type()->bits();
int intbits = Type::lookup_integer_type("int")->integer_type()->bits();
// We can treat ebits == intbits as small even for an unsigned
// integer type, because we will convert the value to int and
// then reject it in the runtime if it is negative.
*small = ebits <= intbits;
return true;
}
go_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 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)
{
Expression* expr = *pexpr;
if (!expr->is_constant()
&& (expr->call_expression() != NULL
|| expr->receive_expression() != NULL))
{
this->found_ = true;
return TRAVERSE_EXIT;
}
return TRAVERSE_CONTINUE;
}
// Return whether calling len or cap on EXPR, of array type, is a
// constant. The language spec says "the expressions len(s) and
// cap(s) are constants if the type of s is an array or pointer to an
// array and the expression s does not contain channel receives or
// (non-constant) function calls."
bool
Builtin_call_expression::array_len_is_constant(Expression* expr)
{
go_assert(expr->type()->deref()->array_type() != NULL
&& !expr->type()->deref()->is_slice_type());
if (expr->is_constant())
return true;
Find_call_expression find_call;
Expression::traverse(&expr, &find_call);
return !find_call.found();
}
// 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();
if (arg_type->array_type() != NULL
&& arg_type->array_type()->length() != NULL)
{
this->seen_ = true;
bool ret = Builtin_call_expression::array_len_is_constant(arg);
this->seen_ = false;
return ret;
}
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())
arg_type = arg_type->make_non_abstract_type();
if (this->seen_)
return false;
int64_t ret;
if (this->code_ == BUILTIN_SIZEOF)
{
this->seen_ = true;
bool ok = arg_type->backend_type_size(this->gogo_, &ret);
this->seen_ = false;
if (!ok)
return false;
}
else if (this->code_ == BUILTIN_ALIGNOF)
{
bool ok;
this->seen_ = true;
if (arg->field_reference_expression() == NULL)
ok = arg_type->backend_type_align(this->gogo_, &ret);
else
{
// Calling unsafe.Alignof(s.f) returns the alignment of
// the type of f when it is used as a field in a struct.
ok = arg_type->backend_type_field_align(this->gogo_, &ret);
}
this->seen_ = false;
if (!ok)
return false;
}
else
go_unreachable();
mpz_t zval;
set_mpz_from_int64(&zval, ret);
nc->set_int(Type::lookup_integer_type("uintptr"), zval);
mpz_clear(zval);
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;
if (this->seen_)
return false;
int64_t 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_);
if (st->is_error_type())
{
go_assert(saw_errors());
return false;
}
int64_t offset;
this->seen_ = true;
bool ok = st->struct_type()->backend_field_offset(this->gogo_,
farg->field_index(),
&offset);
this->seen_ = false;
if (!ok)
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;
}
mpz_t zval;
set_mpz_from_int64(&zval, total_offset);
nc->set_int(Type::lookup_integer_type("uintptr"), zval);
mpz_clear(zval);
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;
mpc_t val;
if (!argnc.to_complex(&val))
return false;
Type* type = Builtin_call_expression::real_imag_type(argnc.type());
if (this->code_ == BUILTIN_REAL)
nc->set_float(type, mpc_realref(val));
else
nc->set_float(type, mpc_imagref(val));
mpc_clear(val);
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(),
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
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();
mpc_t val;
mpc_init2(val, mpc_precision);
mpc_set_fr_fr(val, r, i, MPC_RNDNN);
mpfr_clear(r);
mpfr_clear(i);
Type* type = Builtin_call_expression::complex_type(arg_type);
nc->set_complex(type, val);
mpc_clear(val);
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()
{
if (this->is_error_expression())
return Type::make_error_type();
switch (this->code_)
{
case BUILTIN_INVALID:
default:
return Type::make_error_type();
case BUILTIN_NEW:
{
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_MAKE:
{
const Expression_list* args = this->args();
if (args == NULL || args->empty())
return Type::make_error_type();
return 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;
Type* trailing_arg_types = 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;
case BUILTIN_APPEND:
if (!this->is_varargs()
&& args != NULL
&& !args->empty()
&& args->front()->type()->is_slice_type())
trailing_arg_types =
args->front()->type()->array_type()->element_type();
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 (trailing_arg_types != NULL)
{
arg_type = trailing_arg_types;
trailing_arg_types = NULL;
}
}
}
}
// 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)
go_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->recover_arg_is_set_)
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())
{
this->set_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, Type::COMPARE_TAGS, 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->empty())
{
this->report_error(_("not enough arguments"));
break;
}
Type* slice_type = args->front()->type();
if (!slice_type->is_slice_type())
{
if (slice_type->is_error_type())
break;
if (slice_type->is_nil_type())
go_error_at(args->front()->location(), "use of untyped nil");
else
go_error_at(args->front()->location(),
"argument 1 must be a slice");
this->set_is_error();
break;
}
Type* element_type = slice_type->array_type()->element_type();
if (!element_type->in_heap())
go_error_at(args->front()->location(),
"can't append to slice of go:notinheap type");
if (this->is_varargs())
{
if (!args->back()->type()->is_slice_type()
&& !args->back()->type()->is_string_type())
{
go_error_at(args->back()->location(),
"invalid use of %<...%> with non-slice/non-string");
this->set_is_error();
break;
}
if (args->size() < 2)
{
this->report_error(_("not enough arguments"));
break;
}
if (args->size() > 2)
{
this->report_error(_("too many arguments"));
break;
}
if (args->back()->type()->is_string_type()
&& element_type->integer_type() != NULL
&& element_type->integer_type()->is_byte())
{
// Permit append(s1, s2...) when s1 is a slice of
// bytes and s2 is a string type.
}
else
{
// We have to test for assignment compatibility to a
// slice of the element type, which is not necessarily
// the same as the type of the first argument: the
// first argument might have a named type.
Type* check_type = Type::make_array_type(element_type, NULL);
std::string reason;
if (!Type::are_assignable(check_type, args->back()->type(),
&reason))
{
if (reason.empty())
go_error_at(args->back()->location(),
"argument 2 has invalid type");
else
go_error_at(args->back()->location(),
"argument 2 has invalid type (%s)",
reason.c_str());
this->set_is_error();
break;
}
}
}
else
{
Expression_list::const_iterator pa = args->begin();
int i = 2;
for (++pa; pa != args->end(); ++pa, ++i)
{
std::string reason;
if (!Type::are_assignable(element_type, (*pa)->type(),
&reason))
{
if (reason.empty())
go_error_at((*pa)->location(),
"argument %d has incompatible type", i);
else
go_error_at((*pa)->location(),
"argument %d has incompatible type (%s)",
i, 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(),
Type::COMPARE_TAGS, 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();
}
}
Expression*
Builtin_call_expression::do_copy()
{
Call_expression* bce =
new Builtin_call_expression(this->gogo_, this->fn()->copy(),
(this->args() == NULL
? NULL
: this->args()->copy()),
this->is_varargs(),
this->location());
if (this->varargs_are_lowered())
bce->set_varargs_are_lowered();
if (this->is_deferred())
bce->set_is_deferred();
if (this->is_concurrent())
bce->set_is_concurrent();
return bce;
}
// Return the backend representation for a builtin function.
Bexpression*
Builtin_call_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Location location = this->location();
if (this->is_erroneous_call())
{
go_assert(saw_errors());
return gogo->backend()->error_expression();
}
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->front();
Type* arg_type = arg->type();
if (this->seen_)
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
this->seen_ = true;
this->seen_ = false;
if (arg_type->points_to() != NULL)
{
arg_type = arg_type->points_to();
go_assert(arg_type->array_type() != NULL
&& !arg_type->is_slice_type());
arg = Expression::make_dereference(arg, NIL_CHECK_DEFAULT,
location);
}
Type* int_type = Type::lookup_integer_type("int");
Expression* val;
if (this->code_ == BUILTIN_LEN)
{
if (arg_type->is_string_type())
val = Expression::make_string_info(arg, STRING_INFO_LENGTH,
location);
else if (arg_type->array_type() != NULL)
{
if (this->seen_)
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
this->seen_ = true;
val = arg_type->array_type()->get_length(gogo, arg);
this->seen_ = false;
}
else if (arg_type->map_type() != NULL
|| arg_type->channel_type() != NULL)
{
// The first field is the length. If the pointer is
// nil, the length is zero.
Type* pint_type = Type::make_pointer_type(int_type);
arg = Expression::make_unsafe_cast(pint_type, arg, location);
Expression* nil = Expression::make_nil(location);
nil = Expression::make_cast(pint_type, nil, location);
Expression* cmp = Expression::make_binary(OPERATOR_EQEQ,
arg, nil, location);
Expression* zero = Expression::make_integer_ul(0, int_type,
location);
Expression* indir =
Expression::make_dereference(arg, NIL_CHECK_NOT_NEEDED,
location);
val = Expression::make_conditional(cmp, zero, indir, location);
}
else
go_unreachable();
}
else
{
if (arg_type->array_type() != NULL)
{
if (this->seen_)
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
this->seen_ = true;
val = arg_type->array_type()->get_capacity(gogo, arg);
this->seen_ = false;
}
else if (arg_type->channel_type() != NULL)
{
// The second field is the capacity. If the pointer
// is nil, the capacity is zero.
Type* uintptr_type = Type::lookup_integer_type("uintptr");
Type* pint_type = Type::make_pointer_type(int_type);
Expression* parg = Expression::make_unsafe_cast(uintptr_type,
arg,
location);
int off = int_type->integer_type()->bits() / 8;
Expression* eoff = Expression::make_integer_ul(off,
uintptr_type,
location);
parg = Expression::make_binary(OPERATOR_PLUS, parg, eoff,
location);
parg = Expression::make_unsafe_cast(pint_type, parg, location);
Expression* nil = Expression::make_nil(location);
nil = Expression::make_cast(pint_type, nil, location);
Expression* cmp = Expression::make_binary(OPERATOR_EQEQ,
arg, nil, location);
Expression* zero = Expression::make_integer_ul(0, int_type,
location);
Expression* indir =
Expression::make_dereference(parg, NIL_CHECK_NOT_NEEDED,
location);
val = Expression::make_conditional(cmp, zero, indir, location);
}
else
go_unreachable();
}
return Expression::make_cast(int_type, val,
location)->get_backend(context);
}
case BUILTIN_PRINT:
case BUILTIN_PRINTLN:
{
const bool is_ln = this->code_ == BUILTIN_PRINTLN;
Expression* print_stmts = Runtime::make_call(Runtime::PRINTLOCK,
location, 0);
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())
{
Expression* print_space =
Runtime::make_call(Runtime::PRINTSP, location, 0);
print_stmts =
Expression::make_compound(print_stmts, print_space,
location);
}
Expression* arg = *p;
Type* type = arg->type();
Runtime::Function code;
if (type->is_string_type())
code = Runtime::PRINTSTRING;
else if (type->integer_type() != NULL
&& type->integer_type()->is_unsigned())
{
Type* itype = Type::lookup_integer_type("uint64");
arg = Expression::make_cast(itype, arg, location);
code = Runtime::PRINTUINT;
}
else if (type->integer_type() != NULL)
{
Type* itype = Type::lookup_integer_type("int64");
arg = Expression::make_cast(itype, arg, location);
code = Runtime::PRINTINT;
}
else if (type->float_type() != NULL)
{
Type* dtype = Type::lookup_float_type("float64");
arg = Expression::make_cast(dtype, arg, location);
code = Runtime::PRINTFLOAT;
}
else if (type->complex_type() != NULL)
{
Type* ctype = Type::lookup_complex_type("complex128");
arg = Expression::make_cast(ctype, arg, location);
code = Runtime::PRINTCOMPLEX;
}
else if (type->is_boolean_type())
code = Runtime::PRINTBOOL;
else if (type->points_to() != NULL
|| type->channel_type() != NULL
|| type->map_type() != NULL
|| type->function_type() != NULL)
{
arg = Expression::make_cast(type, arg, location);
code = Runtime::PRINTPOINTER;
}
else if (type->interface_type() != NULL)
{
if (type->interface_type()->is_empty())
code = Runtime::PRINTEFACE;
else
code = Runtime::PRINTIFACE;
}
else if (type->is_slice_type())
code = Runtime::PRINTSLICE;
else
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
Expression* call = Runtime::make_call(code, location, 1, arg);
print_stmts = Expression::make_compound(print_stmts, call,
location);
}
}
if (is_ln)
{
Expression* print_nl =
Runtime::make_call(Runtime::PRINTNL, location, 0);
print_stmts = Expression::make_compound(print_stmts, print_nl,
location);
}
Expression* unlock = Runtime::make_call(Runtime::PRINTUNLOCK,
location, 0);
print_stmts = Expression::make_compound(print_stmts, unlock, location);
return print_stmts->get_backend(context);
}
case BUILTIN_PANIC:
{
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 1);
Expression* arg = args->front();
Type *empty =
Type::make_empty_interface_type(Linemap::predeclared_location());
arg = Expression::convert_for_assignment(gogo, empty, arg, location);
Expression* panic =
Runtime::make_call(Runtime::GOPANIC, location, 1, arg);
return panic->get_backend(context);
}
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();
Type *empty =
Type::make_empty_interface_type(Linemap::predeclared_location());
Expression* nil = Expression::make_nil(location);
nil = Expression::convert_for_assignment(gogo, empty, nil, 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.
Expression* recover = Runtime::make_call((this->is_deferred()
? Runtime::DEFERREDRECOVER
: Runtime::GORECOVER),
location, 0);
Expression* cond =
Expression::make_conditional(arg, recover, nil, location);
return cond->get_backend(context);
}
case BUILTIN_CLOSE:
{
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 1);
Expression* arg = args->front();
Expression* close = Runtime::make_call(Runtime::CLOSE, location,
1, arg);
return close->get_backend(context);
}
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 context->backend()->error_expression();
}
Type* uintptr_type = Type::lookup_integer_type("uintptr");
mpz_t ival;
nc.get_int(&ival);
Expression* int_cst =
Expression::make_integer_z(&ival, uintptr_type, location);
mpz_clear(ival);
return int_cst->get_backend(context);
}
case BUILTIN_COPY:
{
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 2);
Expression* arg1 = args->front();
Expression* arg2 = args->back();
Type* arg1_type = arg1->type();
Array_type* at = arg1_type->array_type();
go_assert(arg1->is_variable());
Expression* call;
Type* arg2_type = arg2->type();
go_assert(arg2->is_variable());
if (arg2_type->is_string_type())
call = Runtime::make_call(Runtime::SLICESTRINGCOPY, location,
2, arg1, arg2);
else
{
Type* et = at->element_type();
if (et->has_pointer())
{
Expression* td = Expression::make_type_descriptor(et,
location);
call = Runtime::make_call(Runtime::TYPEDSLICECOPY, location,
3, td, arg1, arg2);
}
else
{
Expression* sz = Expression::make_type_info(et,
TYPE_INFO_SIZE);
call = Runtime::make_call(Runtime::SLICECOPY, location, 3,
arg1, arg2, sz);
}
}
return call->get_backend(context);
}
case BUILTIN_APPEND:
// Handled in Builtin_call_expression::flatten_append.
go_unreachable();
case BUILTIN_REAL:
case BUILTIN_IMAG:
{
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 1);
Bexpression* ret;
Bexpression* bcomplex = args->front()->get_backend(context);
if (this->code_ == BUILTIN_REAL)
ret = gogo->backend()->real_part_expression(bcomplex, location);
else
ret = gogo->backend()->imag_part_expression(bcomplex, location);
return ret;
}
case BUILTIN_COMPLEX:
{
const Expression_list* args = this->args();
go_assert(args != NULL && args->size() == 2);
Bexpression* breal = args->front()->get_backend(context);
Bexpression* bimag = args->back()->get_backend(context);
return gogo->backend()->complex_expression(breal, bimag, location);
}
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_function_body* efb) const
{
Numeric_constant nc;
if (!this->numeric_constant_value(&nc))
{
go_error_at(this->location(), "value is not constant");
return;
}
if (nc.is_int())
{
mpz_t val;
nc.get_int(&val);
Integer_expression::export_integer(efb, val);
mpz_clear(val);
}
else if (nc.is_float())
{
mpfr_t fval;
nc.get_float(&fval);
Float_expression::export_float(efb, fval);
mpfr_clear(fval);
}
else if (nc.is_complex())
{
mpc_t cval;
nc.get_complex(&cval);
Complex_expression::export_complex(efb, cval);
mpc_clear(cval);
}
else
go_unreachable();
// A trailing space lets us reliably identify the end of the number.
efb->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 we are calling a function in a different package that returns
// an unnamed type, this may be the only chance we get to traverse
// that type. We don't traverse this->type_ because it may be a
// Call_multiple_result_type that will just lead back here.
if (this->type_ != NULL && !this->type_->is_error_type())
{
Function_type *fntype = this->get_function_type();
if (fntype != NULL && Type::traverse(fntype, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
}
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"));
this->set_is_error();
return this;
}
// 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();
call->set_is_multi_value_arg();
if (this->is_varargs_)
{
// It is not clear which result of a multiple result call
// the ellipsis operator should be applied to. If we unpack the
// the call into its individual results here, the ellipsis will be
// applied to the last result.
go_error_at(call->location(),
_("multiple-value argument in single-value context"));
return Expression::make_error(call->location());
}
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())
{
Builtin_call_expression* bce =
new Builtin_call_expression(gogo, this->fn_, this->args_,
this->is_varargs_, loc);
if (this->is_deferred_)
bce->set_is_deferred();
if (this->is_concurrent_)
bce->set_is_concurrent();
return bce;
}
// If this call returns multiple results, create a temporary
// variable to hold them.
if (this->result_count() > 1 && this->call_temp_ == NULL)
{
Struct_field_list* sfl = new Struct_field_list();
Function_type* fntype = this->get_function_type();
const Typed_identifier_list* results = fntype->results();
Location loc = this->location();
int i = 0;
char buf[20];
for (Typed_identifier_list::const_iterator p = results->begin();
p != results->end();
++p, ++i)
{
snprintf(buf, sizeof buf, "res%d", i);
sfl->push_back(Struct_field(Typed_identifier(buf, p->type(), loc)));
}
Struct_type* st = Type::make_struct_type(sfl, loc);
st->set_is_struct_incomparable();
this->call_temp_ = Statement::make_temporary(st, NULL, loc);
inserter->insert(this->call_temp_);
}
// 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(), SLICE_STORAGE_MAY_ESCAPE);
}
// 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());
}
// Handle a couple of special runtime functions. In the runtime
// package, getcallerpc returns the PC of the caller, and
// getcallersp returns the frame pointer of the caller. Implement
// these by turning them into calls to GCC builtin functions. We
// could implement them in normal code, but then we would have to
// explicitly unwind the stack. These functions are intended to be
// efficient. Note that this technique obviously only works for
// direct calls, but that is the only way they are used.
if (gogo->compiling_runtime() && gogo->package_name() == "runtime")
{
Func_expression* fe = this->fn_->func_expression();
if (fe != NULL
&& fe->named_object()->is_function_declaration()
&& fe->named_object()->package() == NULL)
{
std::string n = Gogo::unpack_hidden_name(fe->named_object()->name());
if ((this->args_ == NULL || this->args_->size() == 0)
&& n == "getcallerpc")
{
static Named_object* builtin_return_address;
int arg = 0;
return this->lower_to_builtin(&builtin_return_address,
"__builtin_return_address",
&arg);
}
else if ((this->args_ == NULL || this->args_->size() == 0)
&& n == "getcallersp")
{
static Named_object* builtin_dwarf_cfa;
return this->lower_to_builtin(&builtin_dwarf_cfa,
"__builtin_dwarf_cfa",
NULL);
}
}
}
// If this is a call to an imported function for which we have an
// inlinable function body, add it to the list of functions to give
// to the backend as inlining opportunities.
Func_expression* fe = this->fn_->func_expression();
if (fe != NULL
&& fe->named_object()->is_function_declaration()
&& fe->named_object()->func_declaration_value()->has_imported_body())
gogo->add_imported_inlinable_function(fe->named_object());
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,
Slice_storage_escape_disp escape_disp)
{
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
{
go_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);
}
Slice_construction_expression* sce =
Expression::make_slice_composite_literal(varargs_type, vals, loc);
if (escape_disp == SLICE_STORAGE_DOES_NOT_ESCAPE)
sce->set_storage_does_not_escape();
Expression* val = sce;
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;
}
// Return a call to __builtin_return_address or __builtin_dwarf_cfa.
Expression*
Call_expression::lower_to_builtin(Named_object** pno, const char* name,
int* arg)
{
if (*pno == NULL)
*pno = Gogo::declare_builtin_rf_address(name, arg != NULL);
Location loc = this->location();
Expression* fn = Expression::make_func_reference(*pno, NULL, loc);
Expression_list *args = new Expression_list();
if (arg != NULL)
{
Expression* a = Expression::make_integer_ul(*arg, NULL, loc);
args->push_back(a);
}
Expression* call = Expression::make_call(fn, args, false, loc);
// The builtin functions return void*, but the Go functions return uintptr.
Type* uintptr_type = Type::lookup_integer_type("uintptr");
return Expression::make_cast(uintptr_type, call, loc);
}
// Flatten a call with multiple results into a temporary.
Expression*
Call_expression::do_flatten(Gogo* gogo, Named_object*,
Statement_inserter* inserter)
{
if (this->is_erroneous_call())
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
if (this->is_flattened_)
return this;
this->is_flattened_ = true;
// Add temporary variables for all arguments that require type
// conversion.
Function_type* fntype = this->get_function_type();
if (fntype == NULL)
{
go_assert(saw_errors());
return this;
}
if (this->args_ != NULL && !this->args_->empty()
&& fntype->parameters() != NULL && !fntype->parameters()->empty())
{
bool is_interface_method =
this->fn_->interface_field_reference_expression() != NULL;
Expression_list *args = new Expression_list();
Typed_identifier_list::const_iterator pp = fntype->parameters()->begin();
Expression_list::const_iterator pa = this->args_->begin();
if (!is_interface_method && fntype->is_method())
{
// The receiver argument.
args->push_back(*pa);
++pa;
}
for (; pa != this->args_->end(); ++pa, ++pp)
{
go_assert(pp != fntype->parameters()->end());
if (Type::are_identical(pp->type(), (*pa)->type(),
Type::COMPARE_TAGS, NULL))
args->push_back(*pa);
else
{
Location loc = (*pa)->location();
Expression* arg = *pa;
if (!arg->is_variable())
{
Temporary_statement *temp =
Statement::make_temporary(NULL, arg, loc);
inserter->insert(temp);
arg = Expression::make_temporary_reference(temp, loc);
}
arg = Expression::convert_for_assignment(gogo, pp->type(), arg,
loc);
args->push_back(arg);
}
}
delete this->args_;
this->args_ = args;
}
return this;
}
// 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 that holds the result for a call with multiple
// results.
Temporary_statement*
Call_expression::results() const
{
if (this->call_temp_ == NULL)
{
go_assert(saw_errors());
return NULL;
}
return this->call_temp_;
}
// Set the number of results expected from a call expression.
void
Call_expression::set_expected_result_count(size_t count)
{
go_assert(this->expected_result_count_ == 0);
this->expected_result_count_ = count;
}
// 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;
}
}
// Whether or not this call contains errors, either in the call or the
// arguments to the call.
bool
Call_expression::is_erroneous_call()
{
if (this->is_error_expression() || this->fn()->is_error_expression())
return true;
if (this->args() == NULL)
return false;
for (Expression_list::iterator pa = this->args()->begin();
pa != this->args()->end();
++pa)
{
if ((*pa)->type()->is_error_type() || (*pa)->is_error_expression())
return true;
}
return false;
}
// 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;
if (!Type::are_assignable(parameter_type, argument_type, &reason))
{
if (!issued_error)
{
if (reason.empty())
go_error_at(argument_location, "argument %d has incompatible type", i);
else
go_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;
}
if (this->expected_result_count_ != 0
&& this->expected_result_count_ != this->result_count())
{
if (this->issue_error())
this->report_error(_("function result count mismatch"));
this->set_is_error();
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();
// We dereference the values since receivers are always passed
// as pointers.
std::string reason;
if (!Type::are_assignable(rtype->deref(), first_arg->type()->deref(),
&reason))
{
if (reason.empty())
this->report_error(_("incompatible type for receiver"));
else
{
go_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())
{
go_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 || this->args_->size() == 0)
{
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 if (this->args_->size() == 1
&& this->args_->front()->call_expression() != NULL
&& this->args_->front()->call_expression()->result_count() > 1)
{
// This is F(G()) when G returns more than one result. If the
// results can be matched to parameters, it would have been
// lowered in do_lower. If we get here we know there is a
// mismatch.
if (this->args_->front()->call_expression()->result_count()
< parameters->size())
this->report_error(_("not enough arguments"));
else
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"));
}
}
Expression*
Call_expression::do_copy()
{
Call_expression* call =
Expression::make_call(this->fn_->copy(),
(this->args_ == NULL
? NULL
: this->args_->copy()),
this->is_varargs_, this->location());
if (this->varargs_are_lowered_)
call->set_varargs_are_lowered();
if (this->is_deferred_)
call->set_is_deferred();
if (this->is_concurrent_)
call->set_is_concurrent();
return call;
}
// 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,
Location location)
{
Expression* object = interface_method->get_underlying_object();
Type* unsafe_ptr_type = Type::make_pointer_type(Type::make_void_type());
*first_arg_ptr =
Expression::make_unsafe_cast(unsafe_ptr_type, object, location);
return interface_method->get_function();
}
// Build the call expression.
Bexpression*
Call_expression::do_get_backend(Translate_context* context)
{
Location location = this->location();
if (this->call_ != NULL)
{
// If the call returns multiple results, make a new reference to
// the temporary.
if (this->call_temp_ != NULL)
{
Expression* ref =
Expression::make_temporary_reference(this->call_temp_, location);
return ref->get_backend(context);
}
return this->call_;
}
Function_type* fntype = this->get_function_type();
if (fntype == NULL)
return context->backend()->error_expression();
if (this->fn_->is_error_expression())
return context->backend()->error_expression();
Gogo* gogo = context->gogo();
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;
std::vector<Bexpression*> fn_args;
if (this->args_ == NULL || this->args_->empty())
{
nargs = is_interface_method ? 1 : 0;
if (nargs > 0)
fn_args.resize(1);
}
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;
fn_args.resize(1);
fn_args[0] = this->args_->front()->get_backend(context);
}
else
{
const Typed_identifier_list* params = fntype->parameters();
nargs = this->args_->size();
int i = is_interface_method ? 1 : 0;
nargs += i;
fn_args.resize(nargs);
Typed_identifier_list::const_iterator pp = params->begin();
Expression_list::const_iterator pe = this->args_->begin();
if (!is_interface_method && fntype->is_method())
{
fn_args[i] = (*pe)->get_backend(context);
++pe;
++i;
}
for (; pe != this->args_->end(); ++pe, ++pp, ++i)
{
go_assert(pp != params->end());
Expression* arg =
Expression::convert_for_assignment(gogo, pp->type(), *pe,
location);
fn_args[i] = arg->get_backend(context);
}
go_assert(pp == params->end());
go_assert(i == nargs);
}
Expression* fn;
Expression* closure = NULL;
if (func != NULL)
{
Named_object* no = func->named_object();
fn = Expression::make_func_code_reference(no, location);
if (has_closure)
closure = func->closure();
}
else if (!is_interface_method)
{
closure = this->fn_;
// The backend representation of this function type is a pointer
// to a struct whose first field is the actual function to call.
Type* pfntype =
Type::make_pointer_type(
Type::make_pointer_type(Type::make_void_type()));
fn = Expression::make_unsafe_cast(pfntype, this->fn_, location);
fn = Expression::make_dereference(fn, NIL_CHECK_NOT_NEEDED, location);
}
else
{
Expression* first_arg;
fn = this->interface_method_function(interface_method, &first_arg,
location);
fn_args[0] = first_arg->get_backend(context);
}
Bexpression* bclosure = NULL;
if (has_closure_arg)
bclosure = closure->get_backend(context);
else
go_assert(closure == NULL);
Bexpression* bfn = fn->get_backend(context);
// When not calling a named function directly, use a type conversion
// 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 fntype is not correct.
if (func == NULL && !is_interface_method)
{
Btype* bft = fntype->get_backend_fntype(gogo);
bfn = gogo->backend()->convert_expression(bft, bfn, location);
}
Bfunction* bfunction = NULL;
if (context->function())
bfunction = context->function()->func_value()->get_decl();
Bexpression* call = gogo->backend()->call_expression(bfunction, bfn,
fn_args, bclosure,
location);
if (this->call_temp_ != NULL)
{
// This case occurs when the call returns multiple results.
Expression* ref = Expression::make_temporary_reference(this->call_temp_,
location);
Bexpression* bref = ref->get_backend(context);
Bstatement* bassn = gogo->backend()->assignment_statement(bfunction,
bref, call,
location);
ref = Expression::make_temporary_reference(this->call_temp_, location);
this->call_ = ref->get_backend(context);
return gogo->backend()->compound_expression(bassn, this->call_,
location);
}
this->call_ = call;
return this->call_;
}
// 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);
}
// Class Call_result_expression.
// 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 backend representation. 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.
Bexpression*
Call_result_expression::do_get_backend(Translate_context* context)
{
Call_expression* ce = this->call_->call_expression();
if (ce == NULL)
{
go_assert(this->call_->is_error_expression());
return context->backend()->error_expression();
}
Temporary_statement* ts = ce->results();
if (ts == NULL)
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
Expression* ref = Expression::make_temporary_reference(ts, this->location());
ref = Expression::make_field_reference(ref, this->index_, this->location());
return ref->get_backend(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())
{
go_assert(saw_errors());
return Expression::make_error(location);
}
else if (left->is_type_expression())
{
go_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_dereference(left, NIL_CHECK_DEFAULT, 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)
{
go_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)
{
go_error_at(location, "invalid slice of map");
return Expression::make_error(location);
}
return Expression::make_map_index(left, start, location);
}
else if (cap != NULL)
{
go_error_at(location,
"invalid 3-index slice of object that is not a slice");
return Expression::make_error(location);
}
else if (end != NULL)
{
go_error_at(location,
("attempt to slice object that is not "
"array, slice, or string"));
return Expression::make_error(location);
}
else
{
go_error_at(location,
("attempt to index object that is not "
"array, slice, 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);
}
// Class Array_index_expression.
// 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();
Type_context index_context(Type::lookup_integer_type("int"), false);
if (this->start_->is_constant())
this->start_->determine_type(&index_context);
else
this->start_->determine_type_no_context();
if (this->end_ != NULL)
{
if (this->end_->is_constant())
this->end_->determine_type(&index_context);
else
this->end_->determine_type_no_context();
}
if (this->cap_ != NULL)
{
if (this->cap_->is_constant())
this->cap_->determine_type(&index_context);
else
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)))
{
go_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))
{
go_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))
{
go_error_at(this->cap_->location(), "array index out of bounds");
this->set_is_error();
}
else if (ival_valid && mpz_cmp(ival, cval) > 0)
{
go_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)
{
go_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
// Set the array address taken but not escape. The escape
// analysis will make it escape to heap when needed.
this->array_->address_taken(false);
}
}
// The subexpressions of an array index must be evaluated in order.
// If this is indexing into an array, rather than a slice, then only
// the index should be evaluated. Since this is called for values on
// the left hand side of an assigment, evaluating the array, meaning
// copying the array, will cause a different array to be modified.
bool
Array_index_expression::do_must_eval_subexpressions_in_order(
int* skip) const
{
*skip = this->array_->type()->is_slice_type() ? 0 : 1;
return true;
}
// Flatten array indexing by using temporary variables for slices and indexes.
Expression*
Array_index_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
Location loc = this->location();
Expression* array = this->array_;
Expression* start = this->start_;
Expression* end = this->end_;
Expression* cap = this->cap_;
if (array->is_error_expression()
|| array->type()->is_error_type()
|| start->is_error_expression()
|| start->type()->is_error_type()
|| (end != NULL
&& (end->is_error_expression() || end->type()->is_error_type()))
|| (cap != NULL
&& (cap->is_error_expression() || cap->type()->is_error_type())))
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
Temporary_statement* temp;
if (array->type()->is_slice_type() && !array->is_variable())
{
temp = Statement::make_temporary(NULL, array, loc);
inserter->insert(temp);
this->array_ = Expression::make_temporary_reference(temp, loc);
}
if (!start->is_variable())
{
temp = Statement::make_temporary(NULL, start, loc);
inserter->insert(temp);
this->start_ = Expression::make_temporary_reference(temp, loc);
}
if (end != NULL
&& !end->is_nil_expression()
&& !end->is_variable())
{
temp = Statement::make_temporary(NULL, end, loc);
inserter->insert(temp);
this->end_ = Expression::make_temporary_reference(temp, loc);
}
if (cap != NULL && !cap->is_variable())
{
temp = Statement::make_temporary(NULL, cap, loc);
inserter->insert(temp);
this->cap_ = 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();
}
void
Array_index_expression::do_address_taken(bool escapes)
{
// In &x[0], if x is a slice, then x's address is not taken.
if (!this->array_->type()->is_slice_type())
this->array_->address_taken(escapes);
}
// Get the backend representation for an array index.
Bexpression*
Array_index_expression::do_get_backend(Translate_context* context)
{
Array_type* array_type = this->array_->type()->array_type();
if (array_type == NULL)
{
go_assert(this->array_->type()->is_error());
return context->backend()->error_expression();
}
go_assert(!array_type->is_slice_type() || this->array_->is_variable());
Location loc = this->location();
Gogo* gogo = context->gogo();
Type* int_type = Type::lookup_integer_type("int");
Btype* int_btype = int_type->get_backend(gogo);
// We need to convert the length and capacity to the Go "int" type here
// because the length of a fixed-length array could be of type "uintptr"
// and gimple disallows binary operations between "uintptr" and other
// integer types. FIXME.
Bexpression* length = NULL;
if (this->end_ == NULL || this->end_->is_nil_expression())
{
Expression* len = array_type->get_length(gogo, this->array_);
length = len->get_backend(context);
length = gogo->backend()->convert_expression(int_btype, length, loc);
}
Bexpression* capacity = NULL;
if (this->end_ != NULL)
{
Expression* cap = array_type->get_capacity(gogo, this->array_);
capacity = cap->get_backend(context);
capacity = gogo->backend()->convert_expression(int_btype, capacity, loc);
}
Bexpression* cap_arg = capacity;
if (this->cap_ != NULL)
{
cap_arg = this->cap_->get_backend(context);
cap_arg = gogo->backend()->convert_expression(int_btype, cap_arg, loc);
}
if (length == NULL)
length = cap_arg;
if (this->start_->type()->integer_type() == NULL
&& !Type::are_convertible(int_type, this->start_->type(), NULL))
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
Bexpression* start = this->start_->get_backend(context);
start = gogo->backend()->convert_expression(int_btype, start, loc);
Bexpression* crash = NULL;
Bexpression* bad_index = NULL;
if (this->needs_bounds_check_)
{
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));
crash = gogo->runtime_error(code, loc)->get_backend(context);
bad_index = Expression::check_bounds(this->start_, loc)->get_backend(context);
Bexpression* start_too_large =
gogo->backend()->binary_expression((this->end_ == NULL
? OPERATOR_GE
: OPERATOR_GT),
start,
(this->end_ == NULL
? length
: capacity),
loc);
bad_index = gogo->backend()->binary_expression(OPERATOR_OROR,
start_too_large,
bad_index, loc);
}
Bfunction* bfn = context->function()->func_value()->get_decl();
if (this->end_ == NULL)
{
// Simple array indexing. This has to return an l-value, so
// wrap the index check into START.
if (this->needs_bounds_check_)
start =
gogo->backend()->conditional_expression(bfn, int_btype, bad_index,
crash, start, loc);
Bexpression* ret;
if (array_type->length() != NULL)
{
Bexpression* array = this->array_->get_backend(context);
ret = gogo->backend()->array_index_expression(array, start, loc);
}
else
{
// Slice.
Expression* valptr =
array_type->get_value_pointer(gogo, this->array_,
this->is_lvalue_);
Bexpression* ptr = valptr->get_backend(context);
ptr = gogo->backend()->pointer_offset_expression(ptr, start, loc);
Type* ele_type = this->array_->type()->array_type()->element_type();
Btype* ele_btype = ele_type->get_backend(gogo);
ret = gogo->backend()->indirect_expression(ele_btype, ptr, true, loc);
}
return ret;
}
// Array slice.
if (this->cap_ != NULL)
{
cap_arg = gogo->backend()->convert_expression(int_btype, cap_arg, loc);
if (this->needs_bounds_check_)
{
Bexpression* bounds_bcheck =
Expression::check_bounds(this->cap_, loc)->get_backend(context);
bad_index =
gogo->backend()->binary_expression(OPERATOR_OROR, bounds_bcheck,
bad_index, loc);
Bexpression* cap_too_small =
gogo->backend()->binary_expression(OPERATOR_LT, cap_arg, start, loc);
Bexpression* cap_too_large =
gogo->backend()->binary_expression(OPERATOR_GT, cap_arg, capacity, loc);
Bexpression* bad_cap =
gogo->backend()->binary_expression(OPERATOR_OROR, cap_too_small,
cap_too_large, loc);
bad_index = gogo->backend()->binary_expression(OPERATOR_OROR, bad_cap,
bad_index, loc);
}
}
Bexpression* end;
if (this->end_->is_nil_expression())
end = length;
else
{
end = this->end_->get_backend(context);
end = gogo->backend()->convert_expression(int_btype, end, loc);
if (this->needs_bounds_check_)
{
Bexpression* bounds_bcheck =
Expression::check_bounds(this->end_, loc)->get_backend(context);
bad_index =
gogo->backend()->binary_expression(OPERATOR_OROR, bounds_bcheck,
bad_index, loc);
Bexpression* end_too_small =
gogo->backend()->binary_expression(OPERATOR_LT, end, start, loc);
Bexpression* end_too_large =
gogo->backend()->binary_expression(OPERATOR_GT, end, cap_arg, loc);
Bexpression* bad_end =
gogo->backend()->binary_expression(OPERATOR_OROR, end_too_small,
end_too_large, loc);
bad_index = gogo->backend()->binary_expression(OPERATOR_OROR, bad_end,
bad_index, loc);
}
}
Bexpression* result_length =
gogo->backend()->binary_expression(OPERATOR_MINUS, end, start, loc);
Bexpression* result_capacity =
gogo->backend()->binary_expression(OPERATOR_MINUS, cap_arg, start, loc);
// If the new capacity is zero, don't change val. Otherwise we can
// get a pointer to the next object in memory, keeping it live
// unnecessarily. When the capacity is zero, the actual pointer
// value doesn't matter.
Bexpression* zero =
Expression::make_integer_ul(0, int_type, loc)->get_backend(context);
Bexpression* cond =
gogo->backend()->binary_expression(OPERATOR_EQEQ, result_capacity, zero,
loc);
Bexpression* offset = gogo->backend()->conditional_expression(bfn, int_btype,
cond, zero,
start, loc);
Expression* valptr = array_type->get_value_pointer(gogo, this->array_,
this->is_lvalue_);
Bexpression* val = valptr->get_backend(context);
val = gogo->backend()->pointer_offset_expression(val, offset, loc);
Btype* struct_btype = this->type()->get_backend(gogo);
std::vector<Bexpression*> init;
init.push_back(val);
init.push_back(result_length);
init.push_back(result_capacity);
Bexpression* ret =
gogo->backend()->constructor_expression(struct_btype, init, loc);
if (this->needs_bounds_check_)
ret = gogo->backend()->conditional_expression(bfn, struct_btype, bad_index,
crash, ret, loc);
return ret;
}
// 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);
}
// Class String_index_expression.
// 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;
}
Expression*
String_index_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
Location loc = this->location();
Expression* string = this->string_;
Expression* start = this->start_;
Expression* end = this->end_;
if (string->is_error_expression()
|| string->type()->is_error_type()
|| start->is_error_expression()
|| start->type()->is_error_type()
|| (end != NULL
&& (end->is_error_expression() || end->type()->is_error_type())))
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
Temporary_statement* temp;
if (!this->string_->is_variable())
{
temp = Statement::make_temporary(NULL, this->string_, loc);
inserter->insert(temp);
this->string_ = Expression::make_temporary_reference(temp, loc);
}
if (!this->start_->is_variable())
{
temp = Statement::make_temporary(NULL, this->start_, loc);
inserter->insert(temp);
this->start_ = Expression::make_temporary_reference(temp, loc);
}
if (this->end_ != NULL
&& !this->end_->is_nil_expression()
&& !this->end_->is_variable())
{
temp = Statement::make_temporary(NULL, this->end_, loc);
inserter->insert(temp);
this->end_ = Expression::make_temporary_reference(temp, loc);
}
return this;
}
// 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();
Type_context index_context(Type::lookup_integer_type("int"), false);
if (this->start_->is_constant())
this->start_->determine_type(&index_context);
else
this->start_->determine_type_no_context();
if (this->end_ != NULL)
{
if (this->end_->is_constant())
this->end_->determine_type(&index_context);
else
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
&& (this->end_ == NULL
? mpz_cmp_ui(ival, sval.length()) >= 0
: mpz_cmp_ui(ival, sval.length()) > 0)))
{
go_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))
{
go_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 the backend representation for a string index.
Bexpression*
String_index_expression::do_get_backend(Translate_context* context)
{
Location loc = this->location();
Expression* string_arg = this->string_;
if (this->string_->type()->points_to() != NULL)
string_arg = Expression::make_dereference(this->string_,
NIL_CHECK_NOT_NEEDED, loc);
Expression* bad_index = Expression::check_bounds(this->start_, loc);
int code = (this->end_ == NULL
? RUNTIME_ERROR_STRING_INDEX_OUT_OF_BOUNDS
: RUNTIME_ERROR_STRING_SLICE_OUT_OF_BOUNDS);
Gogo* gogo = context->gogo();
Bexpression* crash = gogo->runtime_error(code, loc)->get_backend(context);
Type* int_type = Type::lookup_integer_type("int");
// It is possible that an error occurred earlier because the start index
// cannot be represented as an integer type. In this case, we shouldn't
// try casting the starting index into an integer since
// Type_conversion_expression will fail to get the backend representation.
// FIXME.
if (this->start_->type()->integer_type() == NULL
&& !Type::are_convertible(int_type, this->start_->type(), NULL))
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
Expression* start = Expression::make_cast(int_type, this->start_, loc);
Bfunction* bfn = context->function()->func_value()->get_decl();
if (this->end_ == NULL)
{
Expression* length =
Expression::make_string_info(this->string_, STRING_INFO_LENGTH, loc);
Expression* start_too_large =
Expression::make_binary(OPERATOR_GE, start, length, loc);
bad_index = Expression::make_binary(OPERATOR_OROR, start_too_large,
bad_index, loc);
Expression* bytes =
Expression::make_string_info(this->string_, STRING_INFO_DATA, loc);
Bexpression* bstart = start->get_backend(context);
Bexpression* ptr = bytes->get_backend(context);
ptr = gogo->backend()->pointer_offset_expression(ptr, bstart, loc);
Btype* ubtype = Type::lookup_integer_type("uint8")->get_backend(gogo);
Bexpression* index =
gogo->backend()->indirect_expression(ubtype, ptr, true, loc);
Btype* byte_btype = bytes->type()->points_to()->get_backend(gogo);
Bexpression* index_error = bad_index->get_backend(context);
return gogo->backend()->conditional_expression(bfn, byte_btype,
index_error, crash,
index, loc);
}
Expression* end = NULL;
if (this->end_->is_nil_expression())
end = Expression::make_integer_sl(-1, int_type, loc);
else
{
Expression* bounds_check = Expression::check_bounds(this->end_, loc);
bad_index =
Expression::make_binary(OPERATOR_OROR, bounds_check, bad_index, loc);
end = Expression::make_cast(int_type, this->end_, loc);
}
Expression* strslice = Runtime::make_call(Runtime::STRING_SLICE, loc, 3,
string_arg, start, end);
Bexpression* bstrslice = strslice->get_backend(context);
Btype* str_btype = strslice->type()->get_backend(gogo);
Bexpression* index_error = bad_index->get_backend(context);
return gogo->backend()->conditional_expression(bfn, str_btype, index_error,
crash, bstrslice, loc);
}
// 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()->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);
}
// We need to pass in a pointer to the key, so flatten the index into a
// temporary variable if it isn't already. The value pointer will be
// dereferenced and checked for nil, so flatten into a temporary to avoid
// recomputation.
Expression*
Map_index_expression::do_flatten(Gogo* gogo, Named_object*,
Statement_inserter* inserter)
{
Location loc = this->location();
Map_type* mt = this->get_map_type();
if (this->index()->is_error_expression()
|| this->index()->type()->is_error_type()
|| mt->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
if (!Type::are_identical(mt->key_type(), this->index_->type(),
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
NULL))
{
if (this->index_->type()->interface_type() != NULL
&& !this->index_->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, this->index_, loc);
inserter->insert(temp);
this->index_ = Expression::make_temporary_reference(temp, loc);
}
this->index_ = Expression::convert_for_assignment(gogo, mt->key_type(),
this->index_, loc);
}
if (!this->index_->is_variable())
{
Temporary_statement* temp = Statement::make_temporary(NULL, this->index_,
loc);
inserter->insert(temp);
this->index_ = Expression::make_temporary_reference(temp, loc);
}
if (this->value_pointer_ == NULL)
this->get_value_pointer(gogo);
if (this->value_pointer_->is_error_expression()
|| this->value_pointer_->type()->is_error_type())
return Expression::make_error(loc);
if (!this->value_pointer_->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, this->value_pointer_, loc);
inserter->insert(temp);
this->value_pointer_ = Expression::make_temporary_reference(temp, loc);
}
return this;
}
// 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();
return mt->val_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
{
go_error_at(this->location(), "incompatible type for map index (%s)",
reason.c_str());
this->set_is_error();
}
}
}
// Get the backend representation for a map index.
Bexpression*
Map_index_expression::do_get_backend(Translate_context* context)
{
Map_type* type = this->get_map_type();
if (type == NULL)
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
go_assert(this->value_pointer_ != NULL
&& this->value_pointer_->is_variable());
Expression* val = Expression::make_dereference(this->value_pointer_,
NIL_CHECK_NOT_NEEDED,
this->location());
return val->get_backend(context);
}
// Get an expression for the map index. This returns an expression
// that evaluates to a pointer to a value. If the key is not in the
// map, the pointer will point to a zero value.
Expression*
Map_index_expression::get_value_pointer(Gogo* gogo)
{
if (this->value_pointer_ == NULL)
{
Map_type* type = this->get_map_type();
if (type == NULL)
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
Location loc = this->location();
Expression* map_ref = this->map_;
Expression* index_ptr = Expression::make_unary(OPERATOR_AND,
this->index_,
loc);
Expression* zero = type->fat_zero_value(gogo);
Expression* map_index;
if (zero == NULL)
map_index =
Runtime::make_call(Runtime::MAPACCESS1, loc, 3,
Expression::make_type_descriptor(type, loc),
map_ref, index_ptr);
else
map_index =
Runtime::make_call(Runtime::MAPACCESS1_FAT, loc, 4,
Expression::make_type_descriptor(type, loc),
map_ref, index_ptr, zero);
Type* val_type = type->val_type();
this->value_pointer_ =
Expression::make_unsafe_cast(Type::make_pointer_type(val_type),
map_index, this->location());
}
return this->value_pointer_;
}
// 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;
// References from functions generated by the compiler don't count.
if (function != NULL && function->func_value()->is_type_specific_function())
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()->unalias()->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.
Expression* length_expr = Expression::make_integer_ul(s.length(), NULL, loc);
Type* byte_type = gogo->lookup_global("byte")->type_value();
Array_type* array_type = Type::make_array_type(byte_type, length_expr);
array_type->set_is_array_incomparable();
Expression_list* bytes = new Expression_list();
for (std::string::const_iterator p = s.begin(); p != s.end(); p++)
{
unsigned char c = static_cast<unsigned char>(*p);
bytes->push_back(Expression::make_integer_ul(c, NULL, loc));
}
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);
gogo->lower_expression(function, inserter, &call);
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 the backend representation for a field reference.
Bexpression*
Field_reference_expression::do_get_backend(Translate_context* context)
{
Bexpression* bstruct = this->expr_->get_backend(context);
return context->gogo()->backend()->struct_field_expression(bstruct,
this->field_index_,
this->location());
}
// 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_dereference(ref, NIL_CHECK_DEFAULT, 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_dereference(mtable, NIL_CHECK_NOT_NEEDED, 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_dereference(expr, NIL_CHECK_DEFAULT,
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_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
if (this->expr_->is_error_expression()
|| this->expr_->type()->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
if (!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 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)
{
go_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", vt, loc)));
sfl->push_back(Struct_field(Typed_identifier("val", type, loc)));
Struct_type* st = Type::make_struct_type(sfl, loc);
st->set_is_struct_incomparable();
Type* closure_type = Type::make_pointer_type(st);
Function_type* new_fntype = orig_fntype->copy_with_names();
std::string thunk_name = gogo->thunk_name();
Named_object* new_no = gogo->start_function(thunk_name, new_fntype,
false, loc);
Variable* cvar = new Variable(closure_type, NULL, false, false, false, loc);
cvar->set_is_used();
cvar->set_is_closure();
Named_object* cp = Named_object::make_variable("$closure" + thunk_name,
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_dereference(arg, NIL_CHECK_NOT_NEEDED, 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 the backend representation for a method value.
Bexpression*
Interface_field_reference_expression::do_get_backend(Translate_context* context)
{
Interface_type* type = this->expr_->type()->interface_type();
if (type == NULL)
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
Named_object* thunk =
Interface_field_reference_expression::create_thunk(context->gogo(),
type, this->name_);
if (thunk->is_erroneous())
{
go_assert(saw_errors());
return context->backend()->error_expression();
}
// 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",
thunk->func_value()->type(),
loc)));
fields->push_back(Struct_field(Typed_identifier("val",
this->expr_->type(),
loc)));
Struct_type* st = Type::make_struct_type(fields, loc);
st->set_is_struct_incomparable();
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);
Bexpression* bclosure =
Expression::make_heap_expression(expr, loc)->get_backend(context);
Gogo* gogo = context->gogo();
Btype* btype = this->type()->get_backend(gogo);
bclosure = gogo->backend()->convert_expression(btype, bclosure, loc);
Expression* nil_check =
Expression::make_binary(OPERATOR_EQEQ, this->expr_,
Expression::make_nil(loc), loc);
Bexpression* bnil_check = nil_check->get_backend(context);
Bexpression* bcrash = gogo->runtime_error(RUNTIME_ERROR_NIL_DEREFERENCE,
loc)->get_backend(context);
Bfunction* bfn = context->function()->func_value()->get_decl();
Bexpression* bcond =
gogo->backend()->conditional_expression(bfn, NULL,
bnil_check, bcrash, NULL, loc);
Bfunction* bfunction = context->function()->func_value()->get_decl();
Bstatement* cond_statement =
gogo->backend()->expression_statement(bfunction, bcond);
return gogo->backend()->compound_expression(cond_statement, bclosure, loc);
}
// 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* left_type = this->left_->type();
Type* type = 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)
{
go_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)
|| (left_type->named_type() != NULL && left_type->points_to() != NULL))
{
if (!is_ambiguous)
go_error_at(location, "type %<%s%s%> has no method %<%s%>",
is_pointer ? "*" : "",
nt->message_name().c_str(),
Gogo::message_name(name).c_str());
else
go_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())
{
go_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);
}
// Class Allocation_expression.
int
Allocation_expression::do_traverse(Traverse* traverse)
{
return Type::traverse(this->type_, traverse);
}
Type*
Allocation_expression::do_type()
{
return Type::make_pointer_type(this->type_);
}
void
Allocation_expression::do_check_types(Gogo*)
{
if (!this->type_->in_heap())
go_error_at(this->location(), "can't heap allocate go:notinheap type");
}
// Make a copy of an allocation expression.
Expression*
Allocation_expression::do_copy()
{
Allocation_expression* alloc =
new Allocation_expression(this->type_->copy_expressions(),
this->location());
if (this->allocate_on_stack_)
alloc->set_allocate_on_stack();
return alloc;
}
// Return the backend representation for an allocation expression.
Bexpression*
Allocation_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Location loc = this->location();
Btype* btype = this->type_->get_backend(gogo);
if (this->allocate_on_stack_)
{
int64_t size;
bool ok = this->type_->backend_type_size(gogo, &size);
if (!ok)
{
go_assert(saw_errors());
return gogo->backend()->error_expression();
}
Bstatement* decl;
Named_object* fn = context->function();
go_assert(fn != NULL);
Bfunction* fndecl = fn->func_value()->get_or_make_decl(gogo, fn);
Bexpression* zero = gogo->backend()->zero_expression(btype);
Bvariable* temp =
gogo->backend()->temporary_variable(fndecl, context->bblock(), btype,
zero, true, loc, &decl);
Bexpression* ret = gogo->backend()->var_expression(temp, loc);
ret = gogo->backend()->address_expression(ret, loc);
ret = gogo->backend()->compound_expression(decl, ret, loc);
return ret;
}
Bexpression* space =
gogo->allocate_memory(this->type_, loc)->get_backend(context);
Btype* pbtype = gogo->backend()->pointer_type(btype);
return gogo->backend()->convert_expression(pbtype, space, loc);
}
// 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);
}
// Class Ordered_value_list.
int
Ordered_value_list::traverse_vals(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<unsigned long>::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;
}
}
}
return TRAVERSE_CONTINUE;
}
// Class Struct_construction_expression.
// Traversal.
int
Struct_construction_expression::do_traverse(Traverse* traverse)
{
if (this->traverse_vals(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 can be used as a constant initializer.
bool
Struct_construction_expression::do_is_static_initializer() 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_static_initializer())
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;
}
// 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())
go_error_at((*pv)->location(),
"incompatible type for field %d in struct construction",
i + 1);
else
go_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());
}
// Copy.
Expression*
Struct_construction_expression::do_copy()
{
Struct_construction_expression* ret =
new Struct_construction_expression(this->type_->copy_expressions(),
(this->vals() == NULL
? NULL
: this->vals()->copy()),
this->location());
if (this->traverse_order() != NULL)
ret->set_traverse_order(this->traverse_order());
return ret;
}
// Flatten a struct construction expression. Store the values into
// temporaries in case they need interface conversion.
Expression*
Struct_construction_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
if (this->vals() == NULL)
return this;
// If this is a constant struct, we don't need temporaries.
if (this->is_constant_struct() || this->is_static_initializer())
return this;
Location loc = this->location();
for (Expression_list::iterator pv = this->vals()->begin();
pv != this->vals()->end();
++pv)
{
if (*pv != NULL)
{
if ((*pv)->is_error_expression() || (*pv)->type()->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
if (!(*pv)->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, *pv, loc);
inserter->insert(temp);
*pv = Expression::make_temporary_reference(temp, loc);
}
}
}
return this;
}
// Return the backend representation for constructing a struct.
Bexpression*
Struct_construction_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Btype* btype = this->type_->get_backend(gogo);
if (this->vals() == NULL)
return gogo->backend()->zero_expression(btype);
const Struct_field_list* fields = this->type_->struct_type()->fields();
Expression_list::const_iterator pv = this->vals()->begin();
std::vector<Bexpression*> init;
for (Struct_field_list::const_iterator pf = fields->begin();
pf != fields->end();
++pf)
{
Btype* fbtype = pf->type()->get_backend(gogo);
if (pv == this->vals()->end())
init.push_back(gogo->backend()->zero_expression(fbtype));
else if (*pv == NULL)
{
init.push_back(gogo->backend()->zero_expression(fbtype));
++pv;
}
else
{
Expression* val =
Expression::convert_for_assignment(gogo, pf->type(),
*pv, this->location());
init.push_back(val->get_backend(context));
++pv;
}
}
if (this->type_->struct_type()->has_padding())
{
// Feed an extra value if there is a padding field.
Btype *fbtype = Type::lookup_integer_type("uint8")->get_backend(gogo);
init.push_back(gogo->backend()->zero_expression(fbtype));
}
return gogo->backend()->constructor_expression(btype, init, this->location());
}
// Export a struct construction.
void
Struct_construction_expression::do_export(Export_function_body* efb) const
{
efb->write_c_string("$convert(");
efb->write_type(this->type_);
for (Expression_list::const_iterator pv = this->vals()->begin();
pv != this->vals()->end();
++pv)
{
efb->write_c_string(", ");
if (*pv != NULL)
(*pv)->export_expression(efb);
}
efb->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);
}
// Class Array_construction_expression.
// Traversal.
int
Array_construction_expression::do_traverse(Traverse* traverse)
{
if (this->traverse_vals(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 can be used a constant initializer.
bool
Array_construction_expression::do_is_static_initializer() 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_static_initializer())
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))
{
go_error_at((*pv)->location(),
"incompatible type for element %d in composite literal",
i + 1);
this->set_is_error();
}
}
}
// Flatten an array construction expression. Store the values into
// temporaries in case they need interface conversion.
Expression*
Array_construction_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
if (this->vals() == NULL)
return this;
// If this is a constant array, we don't need temporaries.
if (this->is_constant_array() || this->is_static_initializer())
return this;
Location loc = this->location();
for (Expression_list::iterator pv = this->vals()->begin();
pv != this->vals()->end();
++pv)
{
if (*pv != NULL)
{
if ((*pv)->is_error_expression() || (*pv)->type()->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
if (!(*pv)->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, *pv, loc);
inserter->insert(temp);
*pv = Expression::make_temporary_reference(temp, loc);
}
}
}
return this;
}
// Get a constructor expression for the array values.
Bexpression*
Array_construction_expression::get_constructor(Translate_context* context,
Btype* array_btype)
{
Type* element_type = this->type_->array_type()->element_type();
std::vector<unsigned long> indexes;
std::vector<Bexpression*> vals;
Gogo* gogo = context->gogo();
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());
if (this->indexes_ == NULL)
indexes.push_back(i);
else
indexes.push_back(*pi);
if (*pv == NULL)
{
Btype* ebtype = element_type->get_backend(gogo);
Bexpression *zv = gogo->backend()->zero_expression(ebtype);
vals.push_back(zv);
}
else
{
Expression* val_expr =
Expression::convert_for_assignment(gogo, element_type, *pv,
this->location());
vals.push_back(val_expr->get_backend(context));
}
if (this->indexes_ != NULL)
++pi;
}
if (this->indexes_ != NULL)
go_assert(pi == this->indexes_->end());
}
return gogo->backend()->array_constructor_expression(array_btype, indexes,
vals, this->location());
}
// Export an array construction.
void
Array_construction_expression::do_export(Export_function_body* efb) const
{
efb->write_c_string("$convert(");
efb->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)
{
efb->write_c_string(", ");
if (this->indexes_ != NULL)
{
char buf[100];
snprintf(buf, sizeof buf, "%lu", *pi);
efb->write_c_string(buf);
efb->write_c_string(":");
}
if (*pv != NULL)
(*pv)->export_expression(efb);
if (this->indexes_ != NULL)
++pi;
}
}
efb->write_c_string(")");
}
// Dump ast representation of an array construction expression.
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_);
this->dump_slice_storage_expression(ast_dump_context);
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() << "}" ;
}
// Class Fixed_array_construction_expression.
Fixed_array_construction_expression::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()); }
// Copy.
Expression*
Fixed_array_construction_expression::do_copy()
{
Type* t = this->type()->copy_expressions();
return new Fixed_array_construction_expression(t, this->indexes(),
(this->vals() == NULL
? NULL
: this->vals()->copy()),
this->location());
}
// Return the backend representation for constructing a fixed array.
Bexpression*
Fixed_array_construction_expression::do_get_backend(Translate_context* context)
{
Type* type = this->type();
Btype* btype = type->get_backend(context->gogo());
return this->get_constructor(context, btype);
}
Expression*
Expression::make_array_composite_literal(Type* type, Expression_list* vals,
Location location)
{
go_assert(type->array_type() != NULL && !type->is_slice_type());
return new Fixed_array_construction_expression(type, NULL, vals, location);
}
// Class Slice_construction_expression.
Slice_construction_expression::Slice_construction_expression(
Type* type, const std::vector<unsigned long>* indexes,
Expression_list* vals, Location location)
: Array_construction_expression(EXPRESSION_SLICE_CONSTRUCTION,
type, indexes, vals, location),
valtype_(NULL), array_val_(NULL), slice_storage_(NULL),
storage_escapes_(true)
{
go_assert(type->is_slice_type());
unsigned long lenval;
Expression* length;
if (vals == NULL || vals->empty())
lenval = 0;
else
{
if (this->indexes() == NULL)
lenval = vals->size();
else
lenval = indexes->back() + 1;
}
Type* int_type = Type::lookup_integer_type("int");
length = Expression::make_integer_ul(lenval, int_type, location);
Type* element_type = type->array_type()->element_type();
Array_type* array_type = Type::make_array_type(element_type, length);
array_type->set_is_array_incomparable();
this->valtype_ = array_type;
}
// Traversal.
int
Slice_construction_expression::do_traverse(Traverse* traverse)
{
if (this->Array_construction_expression::do_traverse(traverse)
== TRAVERSE_EXIT)
return TRAVERSE_EXIT;
if (Type::traverse(this->valtype_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
if (this->array_val_ != NULL
&& Expression::traverse(&this->array_val_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
if (this->slice_storage_ != NULL
&& Expression::traverse(&this->slice_storage_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
// Helper routine to create fixed array value underlying the slice literal.
// May be called during flattening, or later during do_get_backend().
Expression*
Slice_construction_expression::create_array_val()
{
Array_type* array_type = this->type()->array_type();
if (array_type == NULL)
{
go_assert(this->type()->is_error());
return NULL;
}
Location loc = this->location();
go_assert(this->valtype_ != NULL);
Expression_list* vals = this->vals();
return new Fixed_array_construction_expression(
this->valtype_, this->indexes(), vals, loc);
}
// If we're previous established that the slice storage does not
// escape, then create a separate array temp val here for it. We
// need to do this as part of flattening so as to be able to insert
// the new temp statement.
Expression*
Slice_construction_expression::do_flatten(Gogo* gogo, Named_object* no,
Statement_inserter* inserter)
{
if (this->type()->array_type() == NULL)
return NULL;
// Base class flattening first
this->Array_construction_expression::do_flatten(gogo, no, inserter);
// Create a stack-allocated storage temp if storage won't escape
if (!this->storage_escapes_
&& this->slice_storage_ == NULL
&& this->element_count() > 0)
{
Location loc = this->location();
this->array_val_ = this->create_array_val();
go_assert(this->array_val_);
Temporary_statement* temp =
Statement::make_temporary(this->valtype_, this->array_val_, loc);
inserter->insert(temp);
this->slice_storage_ = Expression::make_temporary_reference(temp, loc);
}
return this;
}
// When dumping a slice construction expression that has an explicit
// storeage temp, emit the temp here (if we don't do this the storage
// temp appears unused in the AST dump).
void
Slice_construction_expression::
dump_slice_storage_expression(Ast_dump_context* ast_dump_context) const
{
if (this->slice_storage_ == NULL)
return;
ast_dump_context->ostream() << "storage=" ;
ast_dump_context->dump_expression(this->slice_storage_);
}
// Copy.
Expression*
Slice_construction_expression::do_copy()
{
return new Slice_construction_expression(this->type()->copy_expressions(),
this->indexes(),
(this->vals() == NULL
? NULL
: this->vals()->copy()),
this->location());
}
// Return the backend representation for constructing a slice.
Bexpression*
Slice_construction_expression::do_get_backend(Translate_context* context)
{
if (this->array_val_ == NULL)
this->array_val_ = this->create_array_val();
if (this->array_val_ == NULL)
{
go_assert(this->type()->is_error());
return context->backend()->error_expression();
}
Location loc = this->location();
bool is_static_initializer = this->array_val_->is_static_initializer();
// We have to copy the initial values into heap memory if we are in
// a function or if the values are not constants.
bool copy_to_heap = context->function() != NULL || !is_static_initializer;
Expression* space;
if (this->slice_storage_ != NULL)
{
go_assert(!this->storage_escapes_);
space = Expression::make_unary(OPERATOR_AND, this->slice_storage_, loc);
}
else if (!copy_to_heap)
{
// The initializer will only run once.
space = Expression::make_unary(OPERATOR_AND, this->array_val_, loc);
space->unary_expression()->set_is_slice_init();
}
else
{
go_assert(this->storage_escapes_ || this->element_count() == 0);
space = Expression::make_heap_expression(this->array_val_, loc);
}
Array_type* at = this->valtype_->array_type();
Type* et = at->element_type();
space = Expression::make_unsafe_cast(Type::make_pointer_type(et),
space, loc);
// Build a constructor for the slice.
Expression* len = at->length();
Expression* slice_val =
Expression::make_slice_value(this->type(), space, len, len, loc);
return slice_val->get_backend(context);
}
// Make a slice composite literal. This is used by the type
// descriptor code.
Slice_construction_expression*
Expression::make_slice_composite_literal(Type* type, Expression_list* vals,
Location location)
{
go_assert(type->is_slice_type());
return new Slice_construction_expression(type, NULL, vals, location);
}
// Class Map_construction_expression.
// 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;
}
// Flatten constructor initializer into a temporary variable since
// we need to take its address for __go_construct_map.
Expression*
Map_construction_expression::do_flatten(Gogo* gogo, Named_object*,
Statement_inserter* inserter)
{
if (!this->is_error_expression()
&& this->vals_ != NULL
&& !this->vals_->empty()
&& this->constructor_temp_ == NULL)
{
Map_type* mt = this->type_->map_type();
Type* key_type = mt->key_type();
Type* val_type = mt->val_type();
this->element_type_ = Type::make_builtin_struct_type(2,
"__key", key_type,
"__val", val_type);
Expression_list* value_pairs = new Expression_list();
Location loc = this->location();
size_t i = 0;
for (Expression_list::const_iterator pv = this->vals_->begin();
pv != this->vals_->end();
++pv, ++i)
{
Expression_list* key_value_pair = new Expression_list();
Expression* key = *pv;
if (key->is_error_expression() || key->type()->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
if (key->type()->interface_type() != NULL && !key->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, key, loc);
inserter->insert(temp);
key = Expression::make_temporary_reference(temp, loc);
}
key = Expression::convert_for_assignment(gogo, key_type, key, loc);
++pv;
Expression* val = *pv;
if (val->is_error_expression() || val->type()->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(loc);
}
if (val->type()->interface_type() != NULL && !val->is_variable())
{
Temporary_statement* temp =
Statement::make_temporary(NULL, val, loc);
inserter->insert(temp);
val = Expression::make_temporary_reference(temp, loc);
}
val = Expression::convert_for_assignment(gogo, val_type, val, loc);
key_value_pair->push_back(key);
key_value_pair->push_back(val);
value_pairs->push_back(
Expression::make_struct_composite_literal(this->element_type_,
key_value_pair, loc));
}
Expression* element_count = Expression::make_integer_ul(i, NULL, loc);
Array_type* ctor_type =
Type::make_array_type(this->element_type_, element_count);
ctor_type->set_is_array_incomparable();
Expression* constructor =
new Fixed_array_construction_expression(ctor_type, NULL,
value_pairs, loc);
this->constructor_temp_ =
Statement::make_temporary(NULL, constructor, loc);
constructor->issue_nil_check();
this->constructor_temp_->set_is_address_taken();
inserter->insert(this->constructor_temp_);
}
return this;
}
// 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))
{
go_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))
{
go_error_at((*pv)->location(),
("incompatible type for element %d value "
"in map construction"),
i + 1);
this->set_is_error();
}
}
}
// Copy.
Expression*
Map_construction_expression::do_copy()
{
return new Map_construction_expression(this->type_->copy_expressions(),
(this->vals_ == NULL
? NULL
: this->vals_->copy()),
this->location());
}
// Return the backend representation for constructing a map.
Bexpression*
Map_construction_expression::do_get_backend(Translate_context* context)
{
if (this->is_error_expression())
return context->backend()->error_expression();
Location loc = this->location();
size_t i = 0;
Expression* ventries;
if (this->vals_ == NULL || this->vals_->empty())
ventries = Expression::make_nil(loc);
else
{
go_assert(this->constructor_temp_ != NULL);
i = this->vals_->size() / 2;
Expression* ctor_ref =
Expression::make_temporary_reference(this->constructor_temp_, loc);
ventries = Expression::make_unary(OPERATOR_AND, ctor_ref, loc);
}
Map_type* mt = this->type_->map_type();
if (this->element_type_ == NULL)
this->element_type_ =
Type::make_builtin_struct_type(2,
"__key", mt->key_type(),
"__val", mt->val_type());
Expression* descriptor = Expression::make_type_descriptor(mt, loc);
Type* uintptr_t = Type::lookup_integer_type("uintptr");
Expression* count = Expression::make_integer_ul(i, uintptr_t, loc);
Expression* entry_size =
Expression::make_type_info(this->element_type_, TYPE_INFO_SIZE);
unsigned int field_index;
const Struct_field* valfield =
this->element_type_->find_local_field("__val", &field_index);
Expression* val_offset =
Expression::make_struct_field_offset(this->element_type_, valfield);
Expression* map_ctor =
Runtime::make_call(Runtime::CONSTRUCT_MAP, loc, 5, descriptor, count,
entry_size, val_offset, ventries);
return map_ctor->get_backend(context);
}
// Export an array construction.
void
Map_construction_expression::do_export(Export_function_body* efb) const
{
efb->write_c_string("$convert(");
efb->write_type(this->type_);
for (Expression_list::const_iterator pv = this->vals_->begin();
pv != this->vals_->end();
++pv)
{
efb->write_c_string(", ");
(*pv)->export_expression(efb);
}
efb->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() << "}";
}
// Class Composite_literal_expression.
// 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 = 0; depth < this->depth_; ++depth)
{
if (type->array_type() != NULL)
type = type->array_type()->element_type();
else if (type->map_type() != NULL)
{
if (this->key_path_[depth])
type = type->map_type()->key_type();
else
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 = 0; depth < this->depth_; ++depth)
{
type = type->deref();
if (type->array_type() != NULL)
type = type->array_type()->element_type();
else if (type->map_type() != NULL)
{
if (this->key_path_[depth])
type = type->map_type()->key_type();
else
type = type->map_type()->val_type();
}
else
{
if (!type->is_error())
go_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
{
go_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_expression(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())
|| pf->is_embedded_builtin(gogo))
go_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<unsigned long>* traverse_order = new(std::vector<unsigned long>);
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)
{
go_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();
if (type->named_type() != NULL)
{
// If the named object found for this field name comes from a
// different package than the struct it is a part of, do not count
// this incorrect lookup as a usage of the object's package.
no = name_expr->unknown_expression()->named_object();
if (no->package() != NULL
&& no->package() != type->named_type()->named_object()->package())
no->package()->forget_usage(name_expr);
}
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_ENCLOSED_VAR_REFERENCE:
no = name_expr->enclosed_var_expression()->variable();
break;
case EXPRESSION_FUNC_REFERENCE:
no = name_expr->func_expression()->named_object();
break;
default:
bad_key = true;
break;
}
if (bad_key)
{
go_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)
{
go_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)
{
go_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())
|| sf->is_embedded_builtin(gogo)))
go_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(static_cast<unsigned long>(index));
}
if (!this->all_are_names_)
{
// This is a weird case like bug462 in the testsuite.
if (external_expr == NULL)
go_error_at(this->location(), "unknown field in %qs literal",
(type->named_type() != NULL
? type->named_type()->message_name().c_str()
: "unnamed struct"));
else
go_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;
}
// Index/value/traversal-order triple.
struct IVT_triple {
unsigned long index;
unsigned long traversal_order;
Expression* expr;
IVT_triple(unsigned long i, unsigned long to, Expression *e)
: index(i), traversal_order(to), expr(e) { }
bool operator<(const IVT_triple& other) const
{ return this->index < other.index; }
};
// 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 (std::find(indexes->begin(), indexes->end(), index)
!= indexes->end())
{
go_error_at(val->location(),
"duplicate value for index %lu", index);
return Expression::make_error(location);
}
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))
{
go_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:
go_error_at(index_expr->location(),
"index expression is not integer constant");
return Expression::make_error(location);
case Numeric_constant::NC_UL_NEGATIVE:
go_error_at(index_expr->location(),
"index expression is negative");
return Expression::make_error(location);
case Numeric_constant::NC_UL_BIG:
go_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)
{
go_error_at(index_expr->location(), "index value overflow");
return Expression::make_error(location);
}
if (std::find(indexes->begin(), indexes->end(), index)
!= indexes->end())
{
go_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;
}
std::vector<unsigned long>* traverse_order = NULL;
if (indexes_out_of_order)
{
typedef std::vector<IVT_triple> V;
V v;
v.reserve(indexes->size());
std::vector<unsigned long>::const_iterator pi = indexes->begin();
unsigned long torder = 0;
for (Expression_list::const_iterator pe = vals->begin();
pe != vals->end();
++pe, ++pi, ++torder)
v.push_back(IVT_triple(*pi, torder, *pe));
std::sort(v.begin(), v.end());
delete indexes;
delete vals;
indexes = new std::vector<unsigned long>();
indexes->reserve(v.size());
vals = new Expression_list();
vals->reserve(v.size());
traverse_order = new std::vector<unsigned long>();
traverse_order->reserve(v.size());
for (V::const_iterator p = v.begin(); p != v.end(); ++p)
{
indexes->push_back(p->index);
vals->push_back(p->expr);
traverse_order->push_back(p->traversal_order);
}
}
Expression* ret = this->make_array(type, indexes, vals);
Array_construction_expression* ace = ret->array_literal();
if (ace != NULL && traverse_order != NULL)
ace->set_traverse_order(traverse_order);
return ret;
}
// 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)
{
go_error_at(location, "too many elements in composite literal");
return Expression::make_error(location);
}
}
Expression* elen = Expression::make_integer_ul(size, NULL, location);
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)
{
go_error_at(location,
"too many elements in composite literal");
return Expression::make_error(location);
}
}
else
{
unsigned long max = indexes->back();
if (max >= val)
{
go_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 Slice_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();
Unordered_map(unsigned int, std::vector<Expression*>) st;
Unordered_map(unsigned int, std::vector<Expression*>) nt;
if (this->vals_ != NULL)
{
if (!this->has_keys_)
{
go_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;
go_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);
}
// Check if there are duplicate constant keys.
if (!(*p)->is_constant())
continue;
std::string sval;
Numeric_constant nval;
if ((*p)->string_constant_value(&sval)) // Check string keys.
{
unsigned int h = Gogo::hash_string(sval, 0);
// Search the index h in the hash map.
Unordered_map(unsigned int, std::vector<Expression*>)::iterator mit;
mit = st.find(h);
if (mit == st.end())
{
// No duplicate since h is a new index.
// Create a new vector indexed by h and add it to the hash map.
std::vector<Expression*> l;
l.push_back(*p);
std::pair<unsigned int, std::vector<Expression*> > val(h, l);
st.insert(val);
}
else
{
// Do further check since index h already exists.
for (std::vector<Expression*>::iterator lit =
mit->second.begin();
lit != mit->second.end();
lit++)
{
std::string s;
bool ok = (*lit)->string_constant_value(&s);
go_assert(ok);
if (s == sval)
{
go_error_at((*p)->location(), ("duplicate key "
"in map literal"));
return Expression::make_error(location);
}
}
// Add this new string key to the vector indexed by h.
mit->second.push_back(*p);
}
}
else if ((*p)->numeric_constant_value(&nval)) // Check numeric keys.
{
unsigned int h = nval.hash(0);
Unordered_map(unsigned int, std::vector<Expression*>)::iterator mit;
mit = nt.find(h);
if (mit == nt.end())
{
// No duplicate since h is a new code.
// Create a new vector indexed by h and add it to the hash map.
std::vector<Expression*> l;
l.push_back(*p);
std::pair<unsigned int, std::vector<Expression*> > val(h, l);
nt.insert(val);
}
else
{
// Do further check since h already exists.
for (std::vector<Expression*>::iterator lit =
mit->second.begin();
lit != mit->second.end();
lit++)
{
Numeric_constant rval;
bool ok = (*lit)->numeric_constant_value(&rval);
go_assert(ok);
if (nval.equals(rval))
{
go_error_at((*p)->location(),
"duplicate key in map literal");
return Expression::make_error(location);
}
}
// Add this new numeric key to the vector indexed by h.
mit->second.push_back(*p);
}
}
}
}
return new Map_construction_expression(type, this->vals_, location);
}
// Copy.
Expression*
Composite_literal_expression::do_copy()
{
Composite_literal_expression* ret =
new Composite_literal_expression(this->type_->copy_expressions(),
this->depth_, this->has_keys_,
(this->vals_ == NULL
? NULL
: this->vals_->copy()),
this->all_are_names_,
this->location());
ret->key_path_ = this->key_path_;
return ret;
}
// 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_SLICE_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_SLICE_CONSTRUCTION:
{
const Slice_construction_expression *pace =
static_cast<const Slice_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:
case EXPRESSION_ENCLOSED_VAR_REFERENCE:
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;
}
Expression*
Type_guard_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
if (this->expr_->is_error_expression()
|| this->expr_->type()->is_error_type())
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
if (!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;
}
// 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
go_error_at(this->location(),
("impossible type assertion: "
"type does not implement interface (%s)"),
reason.c_str());
}
this->set_is_error();
}
}
}
// Copy.
Expression*
Type_guard_expression::do_copy()
{
return new Type_guard_expression(this->expr_->copy(),
this->type_->copy_expressions(),
this->location());
}
// Return the backend representation for a type guard expression.
Bexpression*
Type_guard_expression::do_get_backend(Translate_context* context)
{
Expression* conversion;
if (this->type_->interface_type() != NULL)
conversion =
Expression::convert_interface_to_interface(this->type_, this->expr_,
true, this->location());
else
conversion =
Expression::convert_for_assignment(context->gogo(), this->type_,
this->expr_, this->location());
Gogo* gogo = context->gogo();
Btype* bt = this->type_->get_backend(gogo);
Bexpression* bexpr = conversion->get_backend(context);
return gogo->backend()->convert_expression(bt, bexpr, 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_expression.
// Return the type of the expression stored on the heap.
Type*
Heap_expression::do_type()
{ return Type::make_pointer_type(this->expr_->type()); }
// Return the backend representation for allocating an expression on the heap.
Bexpression*
Heap_expression::do_get_backend(Translate_context* context)
{
Type* etype = this->expr_->type();
if (this->expr_->is_error_expression() || etype->is_error())
return context->backend()->error_expression();
Location loc = this->location();
Gogo* gogo = context->gogo();
Btype* btype = this->type()->get_backend(gogo);
Expression* alloc = Expression::make_allocation(etype, loc);
if (this->allocate_on_stack_)
alloc->allocation_expression()->set_allocate_on_stack();
Bexpression* space = alloc->get_backend(context);
Bstatement* decl;
Named_object* fn = context->function();
go_assert(fn != NULL);
Bfunction* fndecl = fn->func_value()->get_or_make_decl(gogo, fn);
Bvariable* space_temp =
gogo->backend()->temporary_variable(fndecl, context->bblock(), btype,
space, true, loc, &decl);
Btype* expr_btype = etype->get_backend(gogo);
Bexpression* bexpr = this->expr_->get_backend(context);
// If this assignment needs a write barrier, call typedmemmove. We
// don't do this in the write barrier pass because in some cases
// backend conversion can introduce new Heap_expression values.
Bstatement* assn;
if (!etype->has_pointer() || this->allocate_on_stack_)
{
space = gogo->backend()->var_expression(space_temp, loc);
Bexpression* ref =
gogo->backend()->indirect_expression(expr_btype, space, true, loc);
assn = gogo->backend()->assignment_statement(fndecl, ref, bexpr, loc);
}
else
{
Bstatement* edecl;
Bvariable* btemp =
gogo->backend()->temporary_variable(fndecl, context->bblock(),
expr_btype, bexpr, true, loc,
&edecl);
Bexpression* btempref = gogo->backend()->var_expression(btemp,
loc);
Bexpression* addr = gogo->backend()->address_expression(btempref, loc);
Expression* td = Expression::make_type_descriptor(etype, loc);
Type* etype_ptr = Type::make_pointer_type(etype);
space = gogo->backend()->var_expression(space_temp, loc);
Expression* elhs = Expression::make_backend(space, etype_ptr, loc);
Expression* erhs = Expression::make_backend(addr, etype_ptr, loc);
Expression* call = Runtime::make_call(Runtime::TYPEDMEMMOVE, loc, 3,
td, elhs, erhs);
Bexpression* bcall = call->get_backend(context);
Bstatement* s = gogo->backend()->expression_statement(fndecl, bcall);
assn = gogo->backend()->compound_statement(edecl, s);
}
decl = gogo->backend()->compound_statement(decl, assn);
space = gogo->backend()->var_expression(space_temp, loc);
return gogo->backend()->compound_expression(decl, space, loc);
}
// Dump ast representation for a heap expression.
void
Heap_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 an expression on the heap.
Expression*
Expression::make_heap_expression(Expression* expr, Location location)
{
return new Heap_expression(expr, location);
}
// Class Receive_expression.
// Return the type of a receive expression.
Type*
Receive_expression::do_type()
{
if (this->is_error_expression())
return Type::make_error_type();
Channel_type* channel_type = this->channel_->type()->channel_type();
if (channel_type == NULL)
{
this->report_error(_("expected channel"));
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())
{
go_assert(saw_errors());
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;
}
}
// Flattening for receive expressions creates a temporary variable to store
// received data in for receives.
Expression*
Receive_expression::do_flatten(Gogo*, Named_object*,
Statement_inserter* inserter)
{
Channel_type* channel_type = this->channel_->type()->channel_type();
if (channel_type == NULL)
{
go_assert(saw_errors());
return this;
}
else if (this->channel_->is_error_expression())
{
go_assert(saw_errors());
return Expression::make_error(this->location());
}
Type* element_type = channel_type->element_type();
if (this->temp_receiver_ == NULL)
{
this->temp_receiver_ = Statement::make_temporary(element_type, NULL,
this->location());
this->temp_receiver_->set_is_address_taken();
inserter->insert(this->temp_receiver_);
}
return this;
}
// Get the backend representation for a receive expression.
Bexpression*
Receive_expression::do_get_backend(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 context->backend()->error_expression();
}
Expression* recv_ref =
Expression::make_temporary_reference(this->temp_receiver_, loc);
Expression* recv_addr =
Expression::make_temporary_reference(this->temp_receiver_, loc);
recv_addr = Expression::make_unary(OPERATOR_AND, recv_addr, loc);
Expression* recv = Runtime::make_call(Runtime::CHANRECV1, loc, 2,
this->channel_, recv_addr);
return Expression::make_compound(recv, recv_ref, loc)->get_backend(context);
}
// 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:
int
do_traverse(Traverse*);
Type*
do_type()
{ return Type::make_type_descriptor_ptr_type(); }
bool
do_is_static_initializer() const
{ return true; }
void
do_determine_type(const Type_context*)
{ }
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(Translate_context* context)
{
return this->type_->type_descriptor_pointer(context->gogo(),
this->location());
}
void
do_dump_expression(Ast_dump_context*) const;
private:
// The type for which this is the descriptor.
Type* type_;
};
int
Type_descriptor_expression::do_traverse(Traverse* traverse)
{
if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
// 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 a pointer to the Garbage Collection symbol
// of a type.
class GC_symbol_expression : public Expression
{
public:
GC_symbol_expression(Type* type)
: Expression(EXPRESSION_GC_SYMBOL, Linemap::predeclared_location()),
type_(type)
{}
protected:
Type*
do_type()
{ return Type::make_pointer_type(Type::lookup_integer_type("uint8")); }
bool
do_is_static_initializer() const
{ return true; }
void
do_determine_type(const Type_context*)
{ }
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(Translate_context* context)
{ return this->type_->gc_symbol_pointer(context->gogo()); }
void
do_dump_expression(Ast_dump_context*) const;
private:
// The type which this gc symbol describes.
Type* type_;
};
// Dump ast representation for a gc symbol expression.
void
GC_symbol_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "gcdata(";
ast_dump_context->dump_type(this->type_);
ast_dump_context->ostream() << ")";
}
// Make a gc symbol expression.
Expression*
Expression::make_gc_symbol(Type* type)
{
return new GC_symbol_expression(type);
}
// An expression that evaluates to a pointer to a symbol holding the
// ptrmask data of a type.
class Ptrmask_symbol_expression : public Expression
{
public:
Ptrmask_symbol_expression(Type* type)
: Expression(EXPRESSION_PTRMASK_SYMBOL, Linemap::predeclared_location()),
type_(type)
{}
protected:
Type*
do_type()
{ return Type::make_pointer_type(Type::lookup_integer_type("uint8")); }
bool
do_is_static_initializer() const
{ return true; }
void
do_determine_type(const Type_context*)
{ }
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(Translate_context*);
void
do_dump_expression(Ast_dump_context*) const;
private:
// The type that this ptrmask symbol describes.
Type* type_;
};
// Return the ptrmask variable.
Bexpression*
Ptrmask_symbol_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
// If this type does not need a gcprog, then we can use the standard
// GC symbol.
int64_t ptrsize, ptrdata;
if (!this->type_->needs_gcprog(gogo, &ptrsize, &ptrdata))
return this->type_->gc_symbol_pointer(gogo);
// Otherwise we have to build a ptrmask variable, and return a
// pointer to it.
Bvariable* bvar = this->type_->gc_ptrmask_var(gogo, ptrsize, ptrdata);
Location bloc = Linemap::predeclared_location();
Bexpression* bref = gogo->backend()->var_expression(bvar, bloc);
Bexpression* baddr = gogo->backend()->address_expression(bref, bloc);
Type* uint8_type = Type::lookup_integer_type("uint8");
Type* pointer_uint8_type = Type::make_pointer_type(uint8_type);
Btype* ubtype = pointer_uint8_type->get_backend(gogo);
return gogo->backend()->convert_expression(ubtype, baddr, bloc);
}
// Dump AST for a ptrmask symbol expression.
void
Ptrmask_symbol_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "ptrmask(";
ast_dump_context->dump_type(this->type_);
ast_dump_context->ostream() << ")";
}
// Make a ptrmask symbol expression.
Expression*
Expression::make_ptrmask_symbol(Type* type)
{
return new Ptrmask_symbol_expression(type);
}
// 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:
bool
do_is_static_initializer() const
{ return true; }
Type*
do_type();
void
do_determine_type(const Type_context*)
{ }
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(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:
case TYPE_INFO_BACKEND_PTRDATA:
case TYPE_INFO_DESCRIPTOR_PTRDATA:
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 the backend representation for type information.
Bexpression*
Type_info_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
bool ok = true;
int64_t val;
switch (this->type_info_)
{
case TYPE_INFO_SIZE:
ok = this->type_->backend_type_size(gogo, &val);
break;
case TYPE_INFO_ALIGNMENT:
ok = this->type_->backend_type_align(gogo, &val);
break;
case TYPE_INFO_FIELD_ALIGNMENT:
ok = this->type_->backend_type_field_align(gogo, &val);
break;
case TYPE_INFO_BACKEND_PTRDATA:
ok = this->type_->backend_type_ptrdata(gogo, &val);
break;
case TYPE_INFO_DESCRIPTOR_PTRDATA:
ok = this->type_->descriptor_ptrdata(gogo, &val);
break;
default:
go_unreachable();
}
if (!ok)
{
go_assert(saw_errors());
return gogo->backend()->error_expression();
}
Expression* e = Expression::make_integer_int64(val, this->type(),
this->location());
return e->get_backend(context);
}
// 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"
: this->type_info_ == TYPE_INFO_BACKEND_PTRDATA ? "backend_ptrdata"
: this->type_info_ == TYPE_INFO_DESCRIPTOR_PTRDATA ? "descriptor_ptrdata"
: "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());
}
Bexpression*
do_get_backend(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 the backend information for slice information.
Bexpression*
Slice_info_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Bexpression* bslice = this->slice_->get_backend(context);
switch (this->slice_info_)
{
case SLICE_INFO_VALUE_POINTER:
case SLICE_INFO_LENGTH:
case SLICE_INFO_CAPACITY:
return gogo->backend()->struct_field_expression(bslice, this->slice_info_,
this->location());
break;
default:
go_unreachable();
}
}
// 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);
}
// Class Slice_value_expression.
int
Slice_value_expression::do_traverse(Traverse* traverse)
{
if (Type::traverse(this->type_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->valmem_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->len_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->cap_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
Expression*
Slice_value_expression::do_copy()
{
return new Slice_value_expression(this->type_->copy_expressions(),
this->valmem_->copy(),
this->len_->copy(), this->cap_->copy(),
this->location());
}
Bexpression*
Slice_value_expression::do_get_backend(Translate_context* context)
{
std::vector<Bexpression*> vals(3);
vals[0] = this->valmem_->get_backend(context);
vals[1] = this->len_->get_backend(context);
vals[2] = this->cap_->get_backend(context);
Gogo* gogo = context->gogo();
Btype* btype = this->type_->get_backend(gogo);
return gogo->backend()->constructor_expression(btype, vals, this->location());
}
void
Slice_value_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "slicevalue(";
ast_dump_context->ostream() << "values: ";
this->valmem_->dump_expression(ast_dump_context);
ast_dump_context->ostream() << ", length: ";
this->len_->dump_expression(ast_dump_context);
ast_dump_context->ostream() << ", capacity: ";
this->cap_->dump_expression(ast_dump_context);
ast_dump_context->ostream() << ")";
}
Expression*
Expression::make_slice_value(Type* at, Expression* valmem, Expression* len,
Expression* cap, Location location)
{
go_assert(at->is_slice_type());
go_assert(valmem->is_nil_expression()
|| (at->array_type()->element_type()
== valmem->type()->points_to()));
return new Slice_value_expression(at, valmem, len, cap, 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());
}
Bexpression*
do_get_backend(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:
{
typedef Unordered_map(Interface_type*, Type*) Hashtable;
static Hashtable result_types;
Interface_type* itype = this->iface_->type()->interface_type();
Hashtable::const_iterator p = result_types.find(itype);
if (p != result_types.end())
return p->second;
Type* pdt = Type::make_type_descriptor_ptr_type();
if (itype->is_empty())
{
result_types[itype] = pdt;
return pdt;
}
Location loc = this->location();
Struct_field_list* sfl = new Struct_field_list();
sfl->push_back(
Struct_field(Typed_identifier("__type_descriptor", pdt, loc)));
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)));
}
Struct_type* st = Type::make_struct_type(sfl, loc);
st->set_is_struct_incomparable();
Pointer_type *pt = Type::make_pointer_type(st);
result_types[itype] = pt;
return pt;
}
case INTERFACE_INFO_OBJECT:
return Type::make_pointer_type(Type::make_void_type());
default:
go_unreachable();
}
}
// Return the backend representation for interface information.
Bexpression*
Interface_info_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Bexpression* biface = this->iface_->get_backend(context);
switch (this->iface_info_)
{
case INTERFACE_INFO_METHODS:
case INTERFACE_INFO_OBJECT:
return gogo->backend()->struct_field_expression(biface, this->iface_info_,
this->location());
break;
default:
go_unreachable();
}
}
// Dump ast representation for an interface info expression.
void
Interface_info_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
bool is_empty = this->iface_->type()->interface_type()->is_empty();
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 && !is_empty ? "methods"
: this->iface_info_ == INTERFACE_INFO_TYPE_DESCRIPTOR ? "type_descriptor"
: 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 that represents an interface value. The first field is either
// a type descriptor for an empty interface or a pointer to the interface method
// table for a non-empty interface. The second field is always the object.
class Interface_value_expression : public Expression
{
public:
Interface_value_expression(Type* type, Expression* first_field,
Expression* obj, Location location)
: Expression(EXPRESSION_INTERFACE_VALUE, location),
type_(type), first_field_(first_field), obj_(obj)
{ }
protected:
int
do_traverse(Traverse*);
Type*
do_type()
{ return this->type_; }
void
do_determine_type(const Type_context*)
{ go_unreachable(); }
Expression*
do_copy()
{
return new Interface_value_expression(this->type_->copy_expressions(),
this->first_field_->copy(),
this->obj_->copy(), this->location());
}
Bexpression*
do_get_backend(Translate_context* context);
void
do_dump_expression(Ast_dump_context*) const;
private:
// The type of the interface value.
Type* type_;
// The first field of the interface (either a type descriptor or a pointer
// to the method table.
Expression* first_field_;
// The underlying object of the interface.
Expression* obj_;
};
int
Interface_value_expression::do_traverse(Traverse* traverse)
{
if (Expression::traverse(&this->first_field_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->obj_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
Bexpression*
Interface_value_expression::do_get_backend(Translate_context* context)
{
std::vector<Bexpression*> vals(2);
vals[0] = this->first_field_->get_backend(context);
vals[1] = this->obj_->get_backend(context);
Gogo* gogo = context->gogo();
Btype* btype = this->type_->get_backend(gogo);
return gogo->backend()->constructor_expression(btype, vals, this->location());
}
void
Interface_value_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "interfacevalue(";
ast_dump_context->ostream() <<
(this->type_->interface_type()->is_empty()
? "type_descriptor: "
: "methods: ");
this->first_field_->dump_expression(ast_dump_context);
ast_dump_context->ostream() << ", object: ";
this->obj_->dump_expression(ast_dump_context);
ast_dump_context->ostream() << ")";
}
Expression*
Expression::make_interface_value(Type* type, Expression* first_value,
Expression* object, Location location)
{
return new Interface_value_expression(type, first_value, object, location);
}
// An interface method table for a pair of types: an interface type and a type
// that implements that interface.
class Interface_mtable_expression : public Expression
{
public:
Interface_mtable_expression(Interface_type* itype, Type* type,
bool is_pointer, Location location)
: Expression(EXPRESSION_INTERFACE_MTABLE, location),
itype_(itype), type_(type), is_pointer_(is_pointer),
method_table_type_(NULL), bvar_(NULL)
{ }
protected:
int
do_traverse(Traverse*);
Type*
do_type();
bool
do_is_static_initializer() const
{ return true; }
void
do_determine_type(const Type_context*)
{ go_unreachable(); }
Expression*
do_copy()
{
Interface_type* itype = this->itype_->copy_expressions()->interface_type();
return new Interface_mtable_expression(itype,
this->type_->copy_expressions(),
this->is_pointer_, this->location());
}
bool
do_is_addressable() const
{ return true; }
Bexpression*
do_get_backend(Translate_context* context);
void
do_dump_expression(Ast_dump_context*) const;
private:
// The interface type for which the methods are defined.
Interface_type* itype_;
// The type to construct the interface method table for.
Type* type_;
// Whether this table contains the method set for the receiver type or the
// pointer receiver type.
bool is_pointer_;
// The type of the method table.
Type* method_table_type_;
// The backend variable that refers to the interface method table.
Bvariable* bvar_;
};
int
Interface_mtable_expression::do_traverse(Traverse* traverse)
{
if (Type::traverse(this->itype_, traverse) == TRAVERSE_EXIT
|| Type::traverse(this->type_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
Type*
Interface_mtable_expression::do_type()
{
if (this->method_table_type_ != NULL)
return this->method_table_type_;
const Typed_identifier_list* interface_methods = this->itype_->methods();
go_assert(!interface_methods->empty());
Struct_field_list* sfl = new Struct_field_list;
Typed_identifier tid("__type_descriptor", Type::make_type_descriptor_ptr_type(),
this->location());
sfl->push_back(Struct_field(tid));
Type* unsafe_ptr_type = Type::make_pointer_type(Type::make_void_type());
for (Typed_identifier_list::const_iterator p = interface_methods->begin();
p != interface_methods->end();
++p)
{
// We want C function pointers here, not func descriptors; model
// using void* pointers.
Typed_identifier method(p->name(), unsafe_ptr_type, p->location());
sfl->push_back(Struct_field(method));
}
Struct_type* st = Type::make_struct_type(sfl, this->location());
st->set_is_struct_incomparable();
this->method_table_type_ = st;
return this->method_table_type_;
}
Bexpression*
Interface_mtable_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Location loc = Linemap::predeclared_location();
if (this->bvar_ != NULL)
return gogo->backend()->var_expression(this->bvar_, this->location());
const Typed_identifier_list* interface_methods = this->itype_->methods();
go_assert(!interface_methods->empty());
std::string mangled_name =
gogo->interface_method_table_name(this->itype_, this->type_,
this->is_pointer_);
// Set is_public if we are converting a named type to an interface
// type that is defined in the same package as the named type, and
// the interface has hidden methods. In that case the interface
// method table will be defined by the package that defines the
// types.
bool is_public = false;
if (this->type_->named_type() != NULL
&& (this->type_->named_type()->named_object()->package()
== this->itype_->package()))
{
for (Typed_identifier_list::const_iterator p = interface_methods->begin();
p != interface_methods->end();
++p)
{
if (Gogo::is_hidden_name(p->name()))
{
is_public = true;
break;
}
}
}
if (is_public
&& this->type_->named_type()->named_object()->package() != NULL)
{
// The interface conversion table is defined elsewhere.
Btype* btype = this->type()->get_backend(gogo);
std::string asm_name(go_selectively_encode_id(mangled_name));
this->bvar_ =
gogo->backend()->immutable_struct_reference(mangled_name, asm_name,
btype, loc);
return gogo->backend()->var_expression(this->bvar_, this->location());
}
// The first element is the type descriptor.
Type* td_type;
if (!this->is_pointer_)
td_type = this->type_;
else
td_type = Type::make_pointer_type(this->type_);
std::vector<Backend::Btyped_identifier> bstructfields;
// Build an interface method table for a type: a type descriptor followed by a
// list of function pointers, one for each interface method. This is used for
// interfaces.
Expression_list* svals = new Expression_list();
Expression* tdescriptor = Expression::make_type_descriptor(td_type, loc);
svals->push_back(tdescriptor);
Btype* tdesc_btype = tdescriptor->type()->get_backend(gogo);
Backend::Btyped_identifier btd("_type", tdesc_btype, loc);
bstructfields.push_back(btd);
Named_type* nt = this->type_->named_type();
Struct_type* st = this->type_->struct_type();
go_assert(nt != NULL || st != NULL);
for (Typed_identifier_list::const_iterator p = interface_methods->begin();
p != interface_methods->end();
++p)
{
bool is_ambiguous;
Method* m;
if (nt != NULL)
m = nt->method_function(p->name(), &is_ambiguous);
else
m = st->method_function(p->name(), &is_ambiguous);
go_assert(m != NULL);
Named_object* no = m->named_object();
go_assert(no->is_function() || no->is_function_declaration());
Btype* fcn_btype = m->type()->get_backend_fntype(gogo);
Backend::Btyped_identifier bmtype(p->name(), fcn_btype, loc);
bstructfields.push_back(bmtype);
svals->push_back(Expression::make_func_code_reference(no, loc));
}
Btype *btype = gogo->backend()->struct_type(bstructfields);
std::vector<Bexpression*> ctor_bexprs;
for (Expression_list::const_iterator pe = svals->begin();
pe != svals->end();
++pe)
{
ctor_bexprs.push_back((*pe)->get_backend(context));
}
Bexpression* ctor =
gogo->backend()->constructor_expression(btype, ctor_bexprs, loc);
std::string asm_name(go_selectively_encode_id(mangled_name));
this->bvar_ = gogo->backend()->immutable_struct(mangled_name, asm_name, false,
!is_public, btype, loc);
gogo->backend()->immutable_struct_set_init(this->bvar_, mangled_name, false,
!is_public, btype, loc, ctor);
return gogo->backend()->var_expression(this->bvar_, loc);
}
void
Interface_mtable_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "__go_"
<< (this->is_pointer_ ? "pimt__" : "imt_");
ast_dump_context->dump_type(this->itype_);
ast_dump_context->ostream() << "__";
ast_dump_context->dump_type(this->type_);
}
Expression*
Expression::make_interface_mtable_ref(Interface_type* itype, Type* type,
bool is_pointer, Location location)
{
return new Interface_mtable_expression(itype, type, is_pointer, 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:
bool
do_is_static_initializer() const
{ return true; }
Type*
do_type()
{ return Type::lookup_integer_type("uintptr"); }
void
do_determine_type(const Type_context*)
{ }
Expression*
do_copy()
{ return this; }
Bexpression*
do_get_backend(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 the backend representation for a struct field offset.
Bexpression*
Struct_field_offset_expression::do_get_backend(Translate_context* context)
{
const Struct_field_list* fields = this->type_->fields();
Struct_field_list::const_iterator p;
unsigned i = 0;
for (p = fields->begin();
p != fields->end();
++p, ++i)
if (&*p == this->field_)
break;
go_assert(&*p == this->field_);
Gogo* gogo = context->gogo();
Btype* btype = this->type_->get_backend(gogo);
int64_t offset = gogo->backend()->type_field_offset(btype, i);
Type* uptr_type = Type::lookup_integer_type("uintptr");
Expression* ret =
Expression::make_integer_int64(offset, uptr_type,
Linemap::predeclared_location());
return ret->get_backend(context);
}
// 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 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()); }
Bexpression*
do_get_backend(Translate_context* context)
{ return 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);
}
// Class Conditional_expression.
// Traversal.
int
Conditional_expression::do_traverse(Traverse* traverse)
{
if (Expression::traverse(&this->cond_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->then_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->else_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
// Return the type of the conditional expression.
Type*
Conditional_expression::do_type()
{
Type* result_type = Type::make_void_type();
if (Type::are_identical(this->then_->type(), this->else_->type(),
Type::COMPARE_ERRORS | Type::COMPARE_TAGS,
NULL))
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;
}
// Determine type for a conditional expression.
void
Conditional_expression::do_determine_type(const Type_context* context)
{
this->cond_->determine_type_no_context();
this->then_->determine_type(context);
this->else_->determine_type(context);
}
// Get the backend representation of a conditional expression.
Bexpression*
Conditional_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Btype* result_btype = this->type()->get_backend(gogo);
Bexpression* cond = this->cond_->get_backend(context);
Bexpression* then = this->then_->get_backend(context);
Bexpression* belse = this->else_->get_backend(context);
Bfunction* bfn = context->function()->func_value()->get_decl();
return gogo->backend()->conditional_expression(bfn, result_btype, cond, then,
belse, this->location());
}
// 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);
}
// Class Compound_expression.
// Traversal.
int
Compound_expression::do_traverse(Traverse* traverse)
{
if (Expression::traverse(&this->init_, traverse) == TRAVERSE_EXIT
|| Expression::traverse(&this->expr_, traverse) == TRAVERSE_EXIT)
return TRAVERSE_EXIT;
return TRAVERSE_CONTINUE;
}
// Return the type of the compound expression.
Type*
Compound_expression::do_type()
{
return this->expr_->type();
}
// Determine type for a compound expression.
void
Compound_expression::do_determine_type(const Type_context* context)
{
this->init_->determine_type_no_context();
this->expr_->determine_type(context);
}
// Get the backend representation of a compound expression.
Bexpression*
Compound_expression::do_get_backend(Translate_context* context)
{
Gogo* gogo = context->gogo();
Bexpression* binit = this->init_->get_backend(context);
Bfunction* bfunction = context->function()->func_value()->get_decl();
Bstatement* init_stmt = gogo->backend()->expression_statement(bfunction,
binit);
Bexpression* bexpr = this->expr_->get_backend(context);
return gogo->backend()->compound_expression(init_stmt, bexpr,
this->location());
}
// Dump ast representation of a conditional expression.
void
Compound_expression::do_dump_expression(
Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "(";
ast_dump_context->dump_expression(this->init_);
ast_dump_context->ostream() << ",";
ast_dump_context->dump_expression(this->expr_);
ast_dump_context->ostream() << ") ";
}
// Make a compound expression.
Expression*
Expression::make_compound(Expression* init, Expression* expr, Location location)
{
return new Compound_expression(init, expr, location);
}
// Class Backend_expression.
int
Backend_expression::do_traverse(Traverse*)
{
return TRAVERSE_CONTINUE;
}
Expression*
Backend_expression::do_copy()
{
return new Backend_expression(this->bexpr_, this->type_->copy_expressions(),
this->location());
}
void
Backend_expression::do_dump_expression(Ast_dump_context* ast_dump_context) const
{
ast_dump_context->ostream() << "backend_expression<";
ast_dump_context->dump_type(this->type_);
ast_dump_context->ostream() << ">";
}
Expression*
Expression::make_backend(Bexpression* bexpr, Type* type, Location location)
{
return new Backend_expression(bexpr, type, location);
}
// Import an expression. This comes at the end in order to see the
// various class definitions.
Expression*
Expression::import_expression(Import_expression* imp, Location loc)
{
int c = imp->peek_char();
if (c == '+' || c == '-' || c == '!' || c == '^' || c == '&' || c == '*')
return Unary_expression::do_import(imp, loc);
else if (c == '(')
return Binary_expression::do_import(imp, loc);
else if (imp->match_c_string("$true")
|| imp->match_c_string("$false")
|| (imp->version() < EXPORT_FORMAT_V3
&& (imp->match_c_string("true")
|| imp->match_c_string("false"))))
return Boolean_expression::do_import(imp, loc);
else if (c == '"')
return String_expression::do_import(imp, loc);
else if (c == '-' || (c >= '0' && c <= '9'))
{
// This handles integers, floats and complex constants.
return Integer_expression::do_import(imp, loc);
}
else if (imp->match_c_string("$nil")
|| (imp->version() < EXPORT_FORMAT_V3
&& imp->match_c_string("nil")))
return Nil_expression::do_import(imp, loc);
else if (imp->match_c_string("$convert")
|| (imp->version() < EXPORT_FORMAT_V3
&& imp->match_c_string("convert")))
return Type_conversion_expression::do_import(imp, loc);
Import_function_body* ifb = imp->ifb();
if (ifb == NULL)
{
go_error_at(imp->location(), "import error: expected expression");
return Expression::make_error(loc);
}
if (ifb->saw_error())
return Expression::make_error(loc);
std::string id = ifb->read_identifier();
if (id.empty())
{
if (!ifb->saw_error())
go_error_at(imp->location(),
"import error: expected identifier at %lu",
static_cast<unsigned long>(ifb->off()));
ifb->set_saw_error();
return Expression::make_error(loc);
}
Named_object* var = ifb->block()->bindings()->lookup(id);
if (var == NULL)
{
if (!ifb->saw_error())
go_error_at(imp->location(), "import error: lookup of %qs failed",
id.c_str());
ifb->set_saw_error();
return Expression::make_error(loc);
}
return Expression::make_var_reference(var, loc);
}
// 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:
mpc_init2(this->u_.complex_val, mpc_precision);
mpc_set(this->u_.complex_val, a.u_.complex_val, MPC_RNDNN);
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:
mpc_init2(this->u_.complex_val, mpc_precision);
mpc_set(this->u_.complex_val, a.u_.complex_val, MPC_RNDNN);
break;
default:
go_unreachable();
}
return *this;
}
// Check equality with another numeric constant.
bool
Numeric_constant::equals(const Numeric_constant& a) const
{
if (this->classification_ != a.classification_)
return false;
if (this->type_ != NULL && a.type_ != NULL
&& !Type::are_identical(this->type_, a.type_,
Type::COMPARE_ALIASES, NULL))
return false;
switch (a.classification_)
{
case NC_INVALID:
break;
case NC_INT:
case NC_RUNE:
return mpz_cmp(this->u_.int_val, a.u_.int_val) == 0;
case NC_FLOAT:
return mpfr_cmp(this->u_.float_val, a.u_.float_val) == 0;
case NC_COMPLEX:
return mpc_cmp(this->u_.complex_val, a.u_.complex_val) == 0;
default:
go_unreachable();
}
return false;
}
// 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:
mpc_clear(this->u_.complex_val);
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.
int bits = 0;
if (type != NULL
&& type->float_type() != NULL
&& !type->float_type()->is_abstract())
bits = type->float_type()->bits();
if (Numeric_constant::is_float_neg_zero(val, bits))
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 mpc_t val)
{
this->clear();
this->classification_ = NC_COMPLEX;
this->type_ = type;
// Avoid negative zero as in set_float.
int bits = 0;
if (type != NULL
&& type->complex_type() != NULL
&& !type->complex_type()->is_abstract())
bits = type->complex_type()->bits() / 2;
mpfr_t real;
mpfr_init_set(real, mpc_realref(val), GMP_RNDN);
if (Numeric_constant::is_float_neg_zero(real, bits))
mpfr_set_ui(real, 0, GMP_RNDN);
mpfr_t imag;
mpfr_init_set(imag, mpc_imagref(val), GMP_RNDN);
if (Numeric_constant::is_float_neg_zero(imag, bits))
mpfr_set_ui(imag, 0, GMP_RNDN);
mpc_init2(this->u_.complex_val, mpc_precision);
mpc_set_fr_fr(this->u_.complex_val, real, imag, MPC_RNDNN);
mpfr_clear(real);
mpfr_clear(imag);
}
// Return whether VAL, at a precision of BITS, is a negative zero.
// BITS may be zero in which case it is ignored.
bool
Numeric_constant::is_float_neg_zero(const mpfr_t val, int bits)
{
if (!mpfr_signbit(val))
return false;
if (mpfr_zero_p(val))
return true;
mp_exp_t min_exp;
switch (bits)
{
case 0:
return false;
case 32:
// In a denormalized float32 the exponent is -126, and there are
// 24 bits of which at least the last must be 1, so the smallest
// representable non-zero exponent is -126 - (24 - 1) == -149.
min_exp = -149;
break;
case 64:
// Minimum exponent is -1022, there are 53 bits.
min_exp = -1074;
break;
default:
go_unreachable();
}
return mpfr_get_exp(val) < min_exp;
}
// 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(mpc_t* val) const
{
go_assert(this->is_complex());
mpc_init2(*val, mpc_precision);
mpc_set(*val, this->u_.complex_val, MPC_RNDNN);
}
// 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(mpc_imagref(this->u_.complex_val)))
return NC_UL_NOTINT;
return this->mpfr_to_unsigned_long(mpc_realref(this->u_.complex_val),
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;
}
// Express value as memory size if possible.
bool
Numeric_constant::to_memory_size(int64_t* val) const
{
switch (this->classification_)
{
case NC_INT:
case NC_RUNE:
return this->mpz_to_memory_size(this->u_.int_val, val);
case NC_FLOAT:
return this->mpfr_to_memory_size(this->u_.float_val, val);
case NC_COMPLEX:
if (!mpfr_zero_p(mpc_imagref(this->u_.complex_val)))
return false;
return this->mpfr_to_memory_size(mpc_realref(this->u_.complex_val), val);
default:
go_unreachable();
}
}
// Express integer as memory size if possible.
bool
Numeric_constant::mpz_to_memory_size(const mpz_t ival, int64_t* val) const
{
if (mpz_sgn(ival) < 0)
return false;
if (mpz_fits_slong_p(ival))
{
*val = static_cast<int64_t>(mpz_get_si(ival));
return true;
}
// Test >= 64, not > 64, because an int64_t can hold 63 bits of a
// positive value.
if (mpz_sizeinbase(ival, 2) >= 64)
return false;
mpz_t q, r;
mpz_init(q);
mpz_init(r);
mpz_tdiv_q_2exp(q, ival, 32);
mpz_tdiv_r_2exp(r, ival, 32);
go_assert(mpz_fits_ulong_p(q) && mpz_fits_ulong_p(r));
*val = ((static_cast<int64_t>(mpz_get_ui(q)) << 32)
+ static_cast<int64_t>(mpz_get_ui(r)));
mpz_clear(r);
mpz_clear(q);
return true;
}
// Express floating point value as memory size if possible.
bool
Numeric_constant::mpfr_to_memory_size(const mpfr_t fval, int64_t* val) const
{
if (!mpfr_integer_p(fval))
return false;
mpz_t ival;
mpz_init(ival);
mpfr_get_z(ival, fval, GMP_RNDN);
bool ret = this->mpz_to_memory_size(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(mpc_imagref(this->u_.complex_val))
|| !mpfr_integer_p(mpc_realref(this->u_.complex_val)))
return false;
mpz_init(*val);
mpfr_get_z(*val, mpc_realref(this->u_.complex_val), 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(mpc_imagref(this->u_.complex_val)))
return false;
mpfr_init_set(*val, mpc_realref(this->u_.complex_val), GMP_RNDN);
return true;
default:
go_unreachable();
}
}
// Convert value to complex.
bool
Numeric_constant::to_complex(mpc_t* val) const
{
mpc_init2(*val, mpc_precision);
switch (this->classification_)
{
case NC_INT:
case NC_RUNE:
mpc_set_z(*val, this->u_.int_val, MPC_RNDNN);
return true;
case NC_FLOAT:
mpc_set_fr(*val, this->u_.float_val, MPC_RNDNN);
return true;
case NC_COMPLEX:
mpc_set(*val, this->u_.complex_val, MPC_RNDNN);
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 || type->is_error())
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
{
ret = false;
if (issue_error)
go_assert(saw_errors());
}
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)
{
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)
{
go_error_at(location,
"floating point constant truncated to integer");
this->set_invalid();
}
return false;
}
mpz_init(val);
mpfr_get_z(val, this->u_.float_val, GMP_RNDN);
break;
case NC_COMPLEX:
if (!mpfr_integer_p(mpc_realref(this->u_.complex_val))
|| !mpfr_zero_p(mpc_imagref(this->u_.complex_val)))
{
if (issue_error)
{
go_error_at(location, "complex constant truncated to integer");
this->set_invalid();
}
return false;
}
mpz_init(val);
mpfr_get_z(val, mpc_realref(this->u_.complex_val), 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)
{
go_error_at(location, "integer constant overflow");
this->set_invalid();
}
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(mpc_imagref(this->u_.complex_val)))
{
if (issue_error)
{
this->set_invalid();
go_error_at(location, "complex constant truncated to float");
}
return false;
}
mpfr_init_set(val, mpc_realref(this->u_.complex_val), 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)
{
go_error_at(location, "floating point constant overflow");
this->set_invalid();
}
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();
}
mpc_t val;
mpc_init2(val, mpc_precision);
switch (this->classification_)
{
case NC_INT:
case NC_RUNE:
mpc_set_z(val, this->u_.int_val, MPC_RNDNN);
break;
case NC_FLOAT:
mpc_set_fr(val, this->u_.float_val, MPC_RNDNN);
break;
case NC_COMPLEX:
mpc_set(val, this->u_.complex_val, MPC_RNDNN);
break;
default:
go_unreachable();
}
bool ret = true;
if (!mpfr_nan_p(mpc_realref(val))
&& !mpfr_inf_p(mpc_realref(val))
&& !mpfr_zero_p(mpc_realref(val))
&& mpfr_get_exp(mpc_realref(val)) > max_exp)
{
if (issue_error)
{
go_error_at(location, "complex real part overflow");
this->set_invalid();
}
ret = false;
}
if (!mpfr_nan_p(mpc_imagref(val))
&& !mpfr_inf_p(mpc_imagref(val))
&& !mpfr_zero_p(mpc_imagref(val))
&& mpfr_get_exp(mpc_imagref(val)) > max_exp)
{
if (issue_error)
{
go_error_at(location, "complex imaginary part overflow");
this->set_invalid();
}
ret = false;
}
if (ret)
{
// Round the constant to the desired type.
mpc_t t;
switch (type->bits())
{
case 64:
mpc_init2(t, 24);
break;
case 128:
mpc_init2(t, 53);
break;
default:
go_unreachable();
}
mpc_set(t, val, MPC_RNDNN);
mpc_set(val, t, MPC_RNDNN);
mpc_clear(t);
this->set_complex(type, val);
}
mpc_clear(val);
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_z(&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, this->type_, loc);
case NC_INVALID:
go_assert(saw_errors());
return Expression::make_error(loc);
default:
go_unreachable();
}
}
// Calculate a hash code with a given seed.
unsigned int
Numeric_constant::hash(unsigned int seed) const
{
unsigned long val;
const unsigned int PRIME = 97;
long e = 0;
double f = 1.0;
mpfr_t m;
switch (this->classification_)
{
case NC_INVALID:
return PRIME;
case NC_INT:
case NC_RUNE:
val = mpz_get_ui(this->u_.int_val);
break;
case NC_COMPLEX:
mpfr_init(m);
mpc_abs(m, this->u_.complex_val, GMP_RNDN);
val = mpfr_get_ui(m, GMP_RNDN);
mpfr_clear(m);
break;
case NC_FLOAT:
f = mpfr_get_d_2exp(&e, this->u_.float_val, GMP_RNDN) * 4294967295.0;
val = static_cast<unsigned long>(e + static_cast<long>(f));
break;
default:
go_unreachable();
}
return (static_cast<unsigned int>(val) + seed) * PRIME;
}