// go-gcc.cc -- Go frontend to gcc IR.
// Copyright (C) 2011, 2012 Free Software Foundation, Inc.
// Contributed by Ian Lance Taylor, Google.
// This file is part of GCC.
// GCC is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3, or (at your option) any later
// version.
// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
// You should have received a copy of the GNU General Public License
// along with GCC; see the file COPYING3. If not see
// .
#include "go-system.h"
// This has to be included outside of extern "C", so we have to
// include it here before tree.h includes it later.
#include
#ifndef ENABLE_BUILD_WITH_CXX
extern "C"
{
#endif
#include "tree.h"
#include "tree-iterator.h"
#include "gimple.h"
#include "toplev.h"
#ifndef ENABLE_BUILD_WITH_CXX
}
#endif
#include "go-c.h"
#include "gogo.h"
#include "backend.h"
// A class wrapping a tree.
class Gcc_tree
{
public:
Gcc_tree(tree t)
: t_(t)
{ }
tree
get_tree() const
{ return this->t_; }
void
set_tree(tree t)
{ this->t_ = t; }
private:
tree t_;
};
// In gcc, types, expressions, and statements are all trees.
class Btype : public Gcc_tree
{
public:
Btype(tree t)
: Gcc_tree(t)
{ }
};
class Bexpression : public Gcc_tree
{
public:
Bexpression(tree t)
: Gcc_tree(t)
{ }
};
class Bstatement : public Gcc_tree
{
public:
Bstatement(tree t)
: Gcc_tree(t)
{ }
};
class Bfunction : public Gcc_tree
{
public:
Bfunction(tree t)
: Gcc_tree(t)
{ }
};
class Bblock : public Gcc_tree
{
public:
Bblock(tree t)
: Gcc_tree(t)
{ }
};
class Bvariable : public Gcc_tree
{
public:
Bvariable(tree t)
: Gcc_tree(t)
{ }
};
class Blabel : public Gcc_tree
{
public:
Blabel(tree t)
: Gcc_tree(t)
{ }
};
// This file implements the interface between the Go frontend proper
// and the gcc IR. This implements specific instantiations of
// abstract classes defined by the Go frontend proper. The Go
// frontend proper class methods of these classes to generate the
// backend representation.
class Gcc_backend : public Backend
{
public:
// Types.
Btype*
error_type()
{ return this->make_type(error_mark_node); }
Btype*
void_type()
{ return this->make_type(void_type_node); }
Btype*
bool_type()
{ return this->make_type(boolean_type_node); }
Btype*
integer_type(bool, int);
Btype*
float_type(int);
Btype*
complex_type(int);
Btype*
pointer_type(Btype*);
Btype*
function_type(const Btyped_identifier&,
const std::vector&,
const std::vector&,
const Location);
Btype*
struct_type(const std::vector&);
Btype*
array_type(Btype*, Bexpression*);
Btype*
placeholder_pointer_type(const std::string&, Location, bool);
bool
set_placeholder_pointer_type(Btype*, Btype*);
bool
set_placeholder_function_type(Btype*, Btype*);
Btype*
placeholder_struct_type(const std::string&, Location);
bool
set_placeholder_struct_type(Btype* placeholder,
const std::vector&);
Btype*
placeholder_array_type(const std::string&, Location);
bool
set_placeholder_array_type(Btype*, Btype*, Bexpression*);
Btype*
named_type(const std::string&, Btype*, Location);
Btype*
circular_pointer_type(Btype*, bool);
bool
is_circular_pointer_type(Btype*);
size_t
type_size(Btype*);
size_t
type_alignment(Btype*);
size_t
type_field_alignment(Btype*);
size_t
type_field_offset(Btype*, size_t index);
// Expressions.
Bexpression*
zero_expression(Btype*);
// Statements.
Bstatement*
error_statement()
{ return this->make_statement(error_mark_node); }
Bstatement*
expression_statement(Bexpression*);
Bstatement*
init_statement(Bvariable* var, Bexpression* init);
Bstatement*
assignment_statement(Bexpression* lhs, Bexpression* rhs, Location);
Bstatement*
return_statement(Bfunction*, const std::vector&,
Location);
Bstatement*
if_statement(Bexpression* condition, Bblock* then_block, Bblock* else_block,
Location);
Bstatement*
switch_statement(Bexpression* value,
const std::vector >& cases,
const std::vector& statements,
Location);
Bstatement*
compound_statement(Bstatement*, Bstatement*);
Bstatement*
statement_list(const std::vector&);
// Blocks.
Bblock*
block(Bfunction*, Bblock*, const std::vector&,
Location, Location);
void
block_add_statements(Bblock*, const std::vector&);
Bstatement*
block_statement(Bblock*);
// Variables.
Bvariable*
error_variable()
{ return new Bvariable(error_mark_node); }
Bvariable*
global_variable(const std::string& package_name,
const std::string& unique_prefix,
const std::string& name,
Btype* btype,
bool is_external,
bool is_hidden,
Location location);
void
global_variable_set_init(Bvariable*, Bexpression*);
Bvariable*
local_variable(Bfunction*, const std::string&, Btype*, bool,
Location);
Bvariable*
parameter_variable(Bfunction*, const std::string&, Btype*, bool,
Location);
Bvariable*
temporary_variable(Bfunction*, Bblock*, Btype*, Bexpression*, bool,
Location, Bstatement**);
Bvariable*
immutable_struct(const std::string&, bool, Btype*, Location);
void
immutable_struct_set_init(Bvariable*, const std::string&, bool, Btype*,
Location, Bexpression*);
Bvariable*
immutable_struct_reference(const std::string&, Btype*, Location);
// Labels.
Blabel*
label(Bfunction*, const std::string& name, Location);
Bstatement*
label_definition_statement(Blabel*);
Bstatement*
goto_statement(Blabel*, Location);
Bexpression*
label_address(Blabel*, Location);
private:
// Make a Bexpression from a tree.
Bexpression*
make_expression(tree t)
{ return new Bexpression(t); }
// Make a Bstatement from a tree.
Bstatement*
make_statement(tree t)
{ return new Bstatement(t); }
// Make a Btype from a tree.
Btype*
make_type(tree t)
{ return new Btype(t); }
Btype*
fill_in_struct(Btype*, const std::vector&);
Btype*
fill_in_array(Btype*, Btype*, Bexpression*);
tree
non_zero_size_type(tree);
};
// A helper function.
static inline tree
get_identifier_from_string(const std::string& str)
{
return get_identifier_with_length(str.data(), str.length());
}
// Get an unnamed integer type.
Btype*
Gcc_backend::integer_type(bool is_unsigned, int bits)
{
tree type;
if (is_unsigned)
{
if (bits == INT_TYPE_SIZE)
type = unsigned_type_node;
else if (bits == CHAR_TYPE_SIZE)
type = unsigned_char_type_node;
else if (bits == SHORT_TYPE_SIZE)
type = short_unsigned_type_node;
else if (bits == LONG_TYPE_SIZE)
type = long_unsigned_type_node;
else if (bits == LONG_LONG_TYPE_SIZE)
type = long_long_unsigned_type_node;
else
type = make_unsigned_type(bits);
}
else
{
if (bits == INT_TYPE_SIZE)
type = integer_type_node;
else if (bits == CHAR_TYPE_SIZE)
type = signed_char_type_node;
else if (bits == SHORT_TYPE_SIZE)
type = short_integer_type_node;
else if (bits == LONG_TYPE_SIZE)
type = long_integer_type_node;
else if (bits == LONG_LONG_TYPE_SIZE)
type = long_long_integer_type_node;
else
type = make_signed_type(bits);
}
return this->make_type(type);
}
// Get an unnamed float type.
Btype*
Gcc_backend::float_type(int bits)
{
tree type;
if (bits == FLOAT_TYPE_SIZE)
type = float_type_node;
else if (bits == DOUBLE_TYPE_SIZE)
type = double_type_node;
else if (bits == LONG_DOUBLE_TYPE_SIZE)
type = long_double_type_node;
else
{
type = make_node(REAL_TYPE);
TYPE_PRECISION(type) = bits;
layout_type(type);
}
return this->make_type(type);
}
// Get an unnamed complex type.
Btype*
Gcc_backend::complex_type(int bits)
{
tree type;
if (bits == FLOAT_TYPE_SIZE * 2)
type = complex_float_type_node;
else if (bits == DOUBLE_TYPE_SIZE * 2)
type = complex_double_type_node;
else if (bits == LONG_DOUBLE_TYPE_SIZE * 2)
type = complex_long_double_type_node;
else
{
type = make_node(REAL_TYPE);
TYPE_PRECISION(type) = bits / 2;
layout_type(type);
type = build_complex_type(type);
}
return this->make_type(type);
}
// Get a pointer type.
Btype*
Gcc_backend::pointer_type(Btype* to_type)
{
tree to_type_tree = to_type->get_tree();
if (to_type_tree == error_mark_node)
return this->error_type();
tree type = build_pointer_type(to_type_tree);
return this->make_type(type);
}
// Make a function type.
Btype*
Gcc_backend::function_type(const Btyped_identifier& receiver,
const std::vector& parameters,
const std::vector& results,
Location location)
{
tree args = NULL_TREE;
tree* pp = &args;
if (receiver.btype != NULL)
{
tree t = receiver.btype->get_tree();
if (t == error_mark_node)
return this->error_type();
*pp = tree_cons(NULL_TREE, t, NULL_TREE);
pp = &TREE_CHAIN(*pp);
}
for (std::vector::const_iterator p = parameters.begin();
p != parameters.end();
++p)
{
tree t = p->btype->get_tree();
if (t == error_mark_node)
return this->error_type();
*pp = tree_cons(NULL_TREE, t, NULL_TREE);
pp = &TREE_CHAIN(*pp);
}
// Varargs is handled entirely at the Go level. When converted to
// GENERIC functions are not varargs.
*pp = void_list_node;
tree result;
if (results.empty())
result = void_type_node;
else if (results.size() == 1)
result = results.front().btype->get_tree();
else
{
result = make_node(RECORD_TYPE);
tree field_trees = NULL_TREE;
pp = &field_trees;
for (std::vector::const_iterator p = results.begin();
p != results.end();
++p)
{
const std::string name = (p->name.empty()
? "UNNAMED"
: p->name);
tree name_tree = get_identifier_from_string(name);
tree field_type_tree = p->btype->get_tree();
if (field_type_tree == error_mark_node)
return this->error_type();
gcc_assert(TYPE_SIZE(field_type_tree) != NULL_TREE);
tree field = build_decl(location.gcc_location(), FIELD_DECL,
name_tree, field_type_tree);
DECL_CONTEXT(field) = result;
*pp = field;
pp = &DECL_CHAIN(field);
}
TYPE_FIELDS(result) = field_trees;
layout_type(result);
}
if (result == error_mark_node)
return this->error_type();
tree fntype = build_function_type(result, args);
if (fntype == error_mark_node)
return this->error_type();
return this->make_type(build_pointer_type(fntype));
}
// Make a struct type.
Btype*
Gcc_backend::struct_type(const std::vector& fields)
{
return this->fill_in_struct(this->make_type(make_node(RECORD_TYPE)), fields);
}
// Fill in the fields of a struct type.
Btype*
Gcc_backend::fill_in_struct(Btype* fill,
const std::vector& fields)
{
tree fill_tree = fill->get_tree();
tree field_trees = NULL_TREE;
tree* pp = &field_trees;
for (std::vector::const_iterator p = fields.begin();
p != fields.end();
++p)
{
tree name_tree = get_identifier_from_string(p->name);
tree type_tree = p->btype->get_tree();
if (type_tree == error_mark_node)
return this->error_type();
tree field = build_decl(p->location.gcc_location(), FIELD_DECL, name_tree,
type_tree);
DECL_CONTEXT(field) = fill_tree;
*pp = field;
pp = &DECL_CHAIN(field);
}
TYPE_FIELDS(fill_tree) = field_trees;
layout_type(fill_tree);
return fill;
}
// Make an array type.
Btype*
Gcc_backend::array_type(Btype* element_btype, Bexpression* length)
{
return this->fill_in_array(this->make_type(make_node(ARRAY_TYPE)),
element_btype, length);
}
// Fill in an array type.
Btype*
Gcc_backend::fill_in_array(Btype* fill, Btype* element_type,
Bexpression* length)
{
tree element_type_tree = element_type->get_tree();
tree length_tree = length->get_tree();
if (element_type_tree == error_mark_node || length_tree == error_mark_node)
return this->error_type();
gcc_assert(TYPE_SIZE(element_type_tree) != NULL_TREE);
length_tree = fold_convert(sizetype, length_tree);
// build_index_type takes the maximum index, which is one less than
// the length.
tree index_type_tree = build_index_type(fold_build2(MINUS_EXPR, sizetype,
length_tree,
size_one_node));
tree fill_tree = fill->get_tree();
TREE_TYPE(fill_tree) = element_type_tree;
TYPE_DOMAIN(fill_tree) = index_type_tree;
TYPE_ADDR_SPACE(fill_tree) = TYPE_ADDR_SPACE(element_type_tree);
layout_type(fill_tree);
if (TYPE_STRUCTURAL_EQUALITY_P(element_type_tree))
SET_TYPE_STRUCTURAL_EQUALITY(fill_tree);
else if (TYPE_CANONICAL(element_type_tree) != element_type_tree
|| TYPE_CANONICAL(index_type_tree) != index_type_tree)
TYPE_CANONICAL(fill_tree) =
build_array_type(TYPE_CANONICAL(element_type_tree),
TYPE_CANONICAL(index_type_tree));
return fill;
}
// Create a placeholder for a pointer type.
Btype*
Gcc_backend::placeholder_pointer_type(const std::string& name,
Location location, bool)
{
tree ret = build_distinct_type_copy(ptr_type_node);
if (!name.empty())
{
tree decl = build_decl(location.gcc_location(), TYPE_DECL,
get_identifier_from_string(name),
ret);
TYPE_NAME(ret) = decl;
}
return this->make_type(ret);
}
// Set the real target type for a placeholder pointer type.
bool
Gcc_backend::set_placeholder_pointer_type(Btype* placeholder,
Btype* to_type)
{
tree pt = placeholder->get_tree();
if (pt == error_mark_node)
return false;
gcc_assert(TREE_CODE(pt) == POINTER_TYPE);
tree tt = to_type->get_tree();
if (tt == error_mark_node)
{
placeholder->set_tree(error_mark_node);
return false;
}
gcc_assert(TREE_CODE(tt) == POINTER_TYPE);
TREE_TYPE(pt) = TREE_TYPE(tt);
if (TYPE_NAME(pt) != NULL_TREE)
{
// Build the data structure gcc wants to see for a typedef.
tree copy = build_variant_type_copy(pt);
TYPE_NAME(copy) = NULL_TREE;
DECL_ORIGINAL_TYPE(TYPE_NAME(pt)) = copy;
}
return true;
}
// Set the real values for a placeholder function type.
bool
Gcc_backend::set_placeholder_function_type(Btype* placeholder, Btype* ft)
{
return this->set_placeholder_pointer_type(placeholder, ft);
}
// Create a placeholder for a struct type.
Btype*
Gcc_backend::placeholder_struct_type(const std::string& name,
Location location)
{
tree ret = make_node(RECORD_TYPE);
if (!name.empty())
{
tree decl = build_decl(location.gcc_location(), TYPE_DECL,
get_identifier_from_string(name),
ret);
TYPE_NAME(ret) = decl;
}
return this->make_type(ret);
}
// Fill in the fields of a placeholder struct type.
bool
Gcc_backend::set_placeholder_struct_type(
Btype* placeholder,
const std::vector& fields)
{
tree t = placeholder->get_tree();
gcc_assert(TREE_CODE(t) == RECORD_TYPE && TYPE_FIELDS(t) == NULL_TREE);
Btype* r = this->fill_in_struct(placeholder, fields);
if (TYPE_NAME(t) != NULL_TREE)
{
// Build the data structure gcc wants to see for a typedef.
tree copy = build_distinct_type_copy(t);
TYPE_NAME(copy) = NULL_TREE;
DECL_ORIGINAL_TYPE(TYPE_NAME(t)) = copy;
}
return r->get_tree() != error_mark_node;
}
// Create a placeholder for an array type.
Btype*
Gcc_backend::placeholder_array_type(const std::string& name,
Location location)
{
tree ret = make_node(ARRAY_TYPE);
tree decl = build_decl(location.gcc_location(), TYPE_DECL,
get_identifier_from_string(name),
ret);
TYPE_NAME(ret) = decl;
return this->make_type(ret);
}
// Fill in the fields of a placeholder array type.
bool
Gcc_backend::set_placeholder_array_type(Btype* placeholder,
Btype* element_btype,
Bexpression* length)
{
tree t = placeholder->get_tree();
gcc_assert(TREE_CODE(t) == ARRAY_TYPE && TREE_TYPE(t) == NULL_TREE);
Btype* r = this->fill_in_array(placeholder, element_btype, length);
// Build the data structure gcc wants to see for a typedef.
tree copy = build_distinct_type_copy(t);
TYPE_NAME(copy) = NULL_TREE;
DECL_ORIGINAL_TYPE(TYPE_NAME(t)) = copy;
return r->get_tree() != error_mark_node;
}
// Return a named version of a type.
Btype*
Gcc_backend::named_type(const std::string& name, Btype* btype,
Location location)
{
tree type = btype->get_tree();
if (type == error_mark_node)
return this->error_type();
// The middle-end expects a basic type to have a name. In Go every
// basic type will have a name. The first time we see a basic type,
// give it whatever Go name we have at this point.
if (TYPE_NAME(type) == NULL_TREE
&& location.gcc_location() == BUILTINS_LOCATION
&& (TREE_CODE(type) == INTEGER_TYPE
|| TREE_CODE(type) == REAL_TYPE
|| TREE_CODE(type) == COMPLEX_TYPE
|| TREE_CODE(type) == BOOLEAN_TYPE))
{
tree decl = build_decl(BUILTINS_LOCATION, TYPE_DECL,
get_identifier_from_string(name),
type);
TYPE_NAME(type) = decl;
return this->make_type(type);
}
tree copy = build_variant_type_copy(type);
tree decl = build_decl(location.gcc_location(), TYPE_DECL,
get_identifier_from_string(name),
copy);
DECL_ORIGINAL_TYPE(decl) = type;
TYPE_NAME(copy) = decl;
return this->make_type(copy);
}
// Return a pointer type used as a marker for a circular type.
Btype*
Gcc_backend::circular_pointer_type(Btype*, bool)
{
return this->make_type(ptr_type_node);
}
// Return whether we might be looking at a circular type.
bool
Gcc_backend::is_circular_pointer_type(Btype* btype)
{
return btype->get_tree() == ptr_type_node;
}
// Return the size of a type.
size_t
Gcc_backend::type_size(Btype* btype)
{
tree t = btype->get_tree();
if (t == error_mark_node)
return 1;
t = TYPE_SIZE_UNIT(t);
gcc_assert(TREE_CODE(t) == INTEGER_CST);
gcc_assert(TREE_INT_CST_HIGH(t) == 0);
unsigned HOST_WIDE_INT val_wide = TREE_INT_CST_LOW(t);
size_t ret = static_cast(val_wide);
gcc_assert(ret == val_wide);
return ret;
}
// Return the alignment of a type.
size_t
Gcc_backend::type_alignment(Btype* btype)
{
tree t = btype->get_tree();
if (t == error_mark_node)
return 1;
return TYPE_ALIGN_UNIT(t);
}
// Return the alignment of a struct field of type BTYPE.
size_t
Gcc_backend::type_field_alignment(Btype* btype)
{
tree t = btype->get_tree();
if (t == error_mark_node)
return 1;
return go_field_alignment(t);
}
// Return the offset of a field in a struct.
size_t
Gcc_backend::type_field_offset(Btype* btype, size_t index)
{
tree struct_tree = btype->get_tree();
if (struct_tree == error_mark_node)
return 0;
gcc_assert(TREE_CODE(struct_tree) == RECORD_TYPE);
tree field = TYPE_FIELDS(struct_tree);
for (; index > 0; --index)
{
field = DECL_CHAIN(field);
gcc_assert(field != NULL_TREE);
}
HOST_WIDE_INT offset_wide = int_byte_position(field);
gcc_assert(offset_wide >= 0);
size_t ret = static_cast(offset_wide);
gcc_assert(ret == static_cast(offset_wide));
return ret;
}
// Return the zero value for a type.
Bexpression*
Gcc_backend::zero_expression(Btype* btype)
{
tree t = btype->get_tree();
tree ret;
if (t == error_mark_node)
ret = error_mark_node;
else
ret = build_zero_cst(t);
return tree_to_expr(ret);
}
// An expression as a statement.
Bstatement*
Gcc_backend::expression_statement(Bexpression* expr)
{
return this->make_statement(expr->get_tree());
}
// Variable initialization.
Bstatement*
Gcc_backend::init_statement(Bvariable* var, Bexpression* init)
{
tree var_tree = var->get_tree();
tree init_tree = init->get_tree();
if (var_tree == error_mark_node || init_tree == error_mark_node)
return this->error_statement();
gcc_assert(TREE_CODE(var_tree) == VAR_DECL);
// To avoid problems with GNU ld, we don't make zero-sized
// externally visible variables. That might lead us to doing an
// initialization of a zero-sized expression to a non-zero sized
// variable, or vice-versa. Avoid crashes by omitting the
// initializer. Such initializations don't mean anything anyhow.
if (int_size_in_bytes(TREE_TYPE(var_tree)) != 0
&& init_tree != NULL_TREE
&& int_size_in_bytes(TREE_TYPE(init_tree)) != 0)
{
DECL_INITIAL(var_tree) = init_tree;
init_tree = NULL_TREE;
}
tree ret = build1_loc(DECL_SOURCE_LOCATION(var_tree), DECL_EXPR,
void_type_node, var_tree);
if (init_tree != NULL_TREE)
ret = build2_loc(DECL_SOURCE_LOCATION(var_tree), COMPOUND_EXPR,
void_type_node, init_tree, ret);
return this->make_statement(ret);
}
// Assignment.
Bstatement*
Gcc_backend::assignment_statement(Bexpression* lhs, Bexpression* rhs,
Location location)
{
tree lhs_tree = lhs->get_tree();
tree rhs_tree = rhs->get_tree();
if (lhs_tree == error_mark_node || rhs_tree == error_mark_node)
return this->error_statement();
// To avoid problems with GNU ld, we don't make zero-sized
// externally visible variables. That might lead us to doing an
// assignment of a zero-sized expression to a non-zero sized
// expression; avoid crashes here by avoiding assignments of
// zero-sized expressions. Such assignments don't really mean
// anything anyhow.
if (int_size_in_bytes(TREE_TYPE(lhs_tree)) == 0
|| int_size_in_bytes(TREE_TYPE(rhs_tree)) == 0)
return this->compound_statement(this->expression_statement(lhs),
this->expression_statement(rhs));
// Sometimes the same unnamed Go type can be created multiple times
// and thus have multiple tree representations. Make sure this does
// not confuse the middle-end.
if (TREE_TYPE(lhs_tree) != TREE_TYPE(rhs_tree))
{
tree lhs_type_tree = TREE_TYPE(lhs_tree);
gcc_assert(TREE_CODE(lhs_type_tree) == TREE_CODE(TREE_TYPE(rhs_tree)));
if (POINTER_TYPE_P(lhs_type_tree)
|| INTEGRAL_TYPE_P(lhs_type_tree)
|| SCALAR_FLOAT_TYPE_P(lhs_type_tree)
|| COMPLEX_FLOAT_TYPE_P(lhs_type_tree))
rhs_tree = fold_convert_loc(location.gcc_location(), lhs_type_tree,
rhs_tree);
else if (TREE_CODE(lhs_type_tree) == RECORD_TYPE
|| TREE_CODE(lhs_type_tree) == ARRAY_TYPE)
{
gcc_assert(int_size_in_bytes(lhs_type_tree)
== int_size_in_bytes(TREE_TYPE(rhs_tree)));
rhs_tree = fold_build1_loc(location.gcc_location(),
VIEW_CONVERT_EXPR,
lhs_type_tree, rhs_tree);
}
}
return this->make_statement(fold_build2_loc(location.gcc_location(),
MODIFY_EXPR,
void_type_node,
lhs_tree, rhs_tree));
}
// Return.
Bstatement*
Gcc_backend::return_statement(Bfunction* bfunction,
const std::vector& vals,
Location location)
{
tree fntree = bfunction->get_tree();
if (fntree == error_mark_node)
return this->error_statement();
tree result = DECL_RESULT(fntree);
if (result == error_mark_node)
return this->error_statement();
tree ret;
if (vals.empty())
ret = fold_build1_loc(location.gcc_location(), RETURN_EXPR, void_type_node,
NULL_TREE);
else if (vals.size() == 1)
{
tree val = vals.front()->get_tree();
if (val == error_mark_node)
return this->error_statement();
tree set = fold_build2_loc(location.gcc_location(), MODIFY_EXPR,
void_type_node, result,
vals.front()->get_tree());
ret = fold_build1_loc(location.gcc_location(), RETURN_EXPR,
void_type_node, set);
}
else
{
// To return multiple values, copy the values into a temporary
// variable of the right structure type, and then assign the
// temporary variable to the DECL_RESULT in the return
// statement.
tree stmt_list = NULL_TREE;
tree rettype = TREE_TYPE(result);
tree rettmp = create_tmp_var(rettype, "RESULT");
tree field = TYPE_FIELDS(rettype);
for (std::vector::const_iterator p = vals.begin();
p != vals.end();
p++, field = DECL_CHAIN(field))
{
gcc_assert(field != NULL_TREE);
tree ref = fold_build3_loc(location.gcc_location(), COMPONENT_REF,
TREE_TYPE(field), rettmp, field,
NULL_TREE);
tree val = (*p)->get_tree();
if (val == error_mark_node)
return this->error_statement();
tree set = fold_build2_loc(location.gcc_location(), MODIFY_EXPR,
void_type_node,
ref, (*p)->get_tree());
append_to_statement_list(set, &stmt_list);
}
gcc_assert(field == NULL_TREE);
tree set = fold_build2_loc(location.gcc_location(), MODIFY_EXPR,
void_type_node,
result, rettmp);
tree ret_expr = fold_build1_loc(location.gcc_location(), RETURN_EXPR,
void_type_node, set);
append_to_statement_list(ret_expr, &stmt_list);
ret = stmt_list;
}
return this->make_statement(ret);
}
// If.
Bstatement*
Gcc_backend::if_statement(Bexpression* condition, Bblock* then_block,
Bblock* else_block, Location location)
{
tree cond_tree = condition->get_tree();
tree then_tree = then_block->get_tree();
tree else_tree = else_block == NULL ? NULL_TREE : else_block->get_tree();
if (cond_tree == error_mark_node
|| then_tree == error_mark_node
|| else_tree == error_mark_node)
return this->error_statement();
tree ret = build3_loc(location.gcc_location(), COND_EXPR, void_type_node,
cond_tree, then_tree, else_tree);
return this->make_statement(ret);
}
// Switch.
Bstatement*
Gcc_backend::switch_statement(
Bexpression* value,
const std::vector >& cases,
const std::vector& statements,
Location switch_location)
{
gcc_assert(cases.size() == statements.size());
tree stmt_list = NULL_TREE;
std::vector >::const_iterator pc = cases.begin();
for (std::vector::const_iterator ps = statements.begin();
ps != statements.end();
++ps, ++pc)
{
if (pc->empty())
{
source_location loc = (*ps != NULL
? EXPR_LOCATION((*ps)->get_tree())
: UNKNOWN_LOCATION);
tree label = create_artificial_label(loc);
tree c = build_case_label(NULL_TREE, NULL_TREE, label);
append_to_statement_list(c, &stmt_list);
}
else
{
for (std::vector::const_iterator pcv = pc->begin();
pcv != pc->end();
++pcv)
{
tree t = (*pcv)->get_tree();
if (t == error_mark_node)
return this->error_statement();
source_location loc = EXPR_LOCATION(t);
tree label = create_artificial_label(loc);
tree c = build_case_label((*pcv)->get_tree(), NULL_TREE, label);
append_to_statement_list(c, &stmt_list);
}
}
if (*ps != NULL)
{
tree t = (*ps)->get_tree();
if (t == error_mark_node)
return this->error_statement();
append_to_statement_list(t, &stmt_list);
}
}
tree tv = value->get_tree();
if (tv == error_mark_node)
return this->error_statement();
tree t = build3_loc(switch_location.gcc_location(), SWITCH_EXPR,
void_type_node, tv, stmt_list, NULL_TREE);
return this->make_statement(t);
}
// Pair of statements.
Bstatement*
Gcc_backend::compound_statement(Bstatement* s1, Bstatement* s2)
{
tree stmt_list = NULL_TREE;
tree t = s1->get_tree();
if (t == error_mark_node)
return this->error_statement();
append_to_statement_list(t, &stmt_list);
t = s2->get_tree();
if (t == error_mark_node)
return this->error_statement();
append_to_statement_list(t, &stmt_list);
return this->make_statement(stmt_list);
}
// List of statements.
Bstatement*
Gcc_backend::statement_list(const std::vector& statements)
{
tree stmt_list = NULL_TREE;
for (std::vector::const_iterator p = statements.begin();
p != statements.end();
++p)
{
tree t = (*p)->get_tree();
if (t == error_mark_node)
return this->error_statement();
append_to_statement_list(t, &stmt_list);
}
return this->make_statement(stmt_list);
}
// Make a block. For some reason gcc uses a dual structure for
// blocks: BLOCK tree nodes and BIND_EXPR tree nodes. Since the
// BIND_EXPR node points to the BLOCK node, we store the BIND_EXPR in
// the Bblock.
Bblock*
Gcc_backend::block(Bfunction* function, Bblock* enclosing,
const std::vector& vars,
Location start_location,
Location)
{
tree block_tree = make_node(BLOCK);
if (enclosing == NULL)
{
// FIXME: Permitting FUNCTION to be NULL is a temporary measure
// until we have a proper representation of the init function.
tree fndecl;
if (function == NULL)
fndecl = current_function_decl;
else
fndecl = function->get_tree();
gcc_assert(fndecl != NULL_TREE);
// We may have already created a block for local variables when
// we take the address of a parameter.
if (DECL_INITIAL(fndecl) == NULL_TREE)
{
BLOCK_SUPERCONTEXT(block_tree) = fndecl;
DECL_INITIAL(fndecl) = block_tree;
}
else
{
tree superblock_tree = DECL_INITIAL(fndecl);
BLOCK_SUPERCONTEXT(block_tree) = superblock_tree;
tree* pp;
for (pp = &BLOCK_SUBBLOCKS(superblock_tree);
*pp != NULL_TREE;
pp = &BLOCK_CHAIN(*pp))
;
*pp = block_tree;
}
}
else
{
tree superbind_tree = enclosing->get_tree();
tree superblock_tree = BIND_EXPR_BLOCK(superbind_tree);
gcc_assert(TREE_CODE(superblock_tree) == BLOCK);
BLOCK_SUPERCONTEXT(block_tree) = superblock_tree;
tree* pp;
for (pp = &BLOCK_SUBBLOCKS(superblock_tree);
*pp != NULL_TREE;
pp = &BLOCK_CHAIN(*pp))
;
*pp = block_tree;
}
tree* pp = &BLOCK_VARS(block_tree);
for (std::vector::const_iterator pv = vars.begin();
pv != vars.end();
++pv)
{
*pp = (*pv)->get_tree();
if (*pp != error_mark_node)
pp = &DECL_CHAIN(*pp);
}
*pp = NULL_TREE;
TREE_USED(block_tree) = 1;
tree bind_tree = build3_loc(start_location.gcc_location(), BIND_EXPR,
void_type_node, BLOCK_VARS(block_tree),
NULL_TREE, block_tree);
TREE_SIDE_EFFECTS(bind_tree) = 1;
return new Bblock(bind_tree);
}
// Add statements to a block.
void
Gcc_backend::block_add_statements(Bblock* bblock,
const std::vector& statements)
{
tree stmt_list = NULL_TREE;
for (std::vector::const_iterator p = statements.begin();
p != statements.end();
++p)
{
tree s = (*p)->get_tree();
if (s != error_mark_node)
append_to_statement_list(s, &stmt_list);
}
tree bind_tree = bblock->get_tree();
gcc_assert(TREE_CODE(bind_tree) == BIND_EXPR);
BIND_EXPR_BODY(bind_tree) = stmt_list;
}
// Return a block as a statement.
Bstatement*
Gcc_backend::block_statement(Bblock* bblock)
{
tree bind_tree = bblock->get_tree();
gcc_assert(TREE_CODE(bind_tree) == BIND_EXPR);
return this->make_statement(bind_tree);
}
// This is not static because we declare it with GTY(()) in go-c.h.
tree go_non_zero_struct;
// Return a type corresponding to TYPE with non-zero size.
tree
Gcc_backend::non_zero_size_type(tree type)
{
if (int_size_in_bytes(type) != 0)
return type;
switch (TREE_CODE(type))
{
case RECORD_TYPE:
{
if (go_non_zero_struct == NULL_TREE)
{
type = make_node(RECORD_TYPE);
tree field = build_decl(UNKNOWN_LOCATION, FIELD_DECL,
get_identifier("dummy"),
boolean_type_node);
DECL_CONTEXT(field) = type;
TYPE_FIELDS(type) = field;
layout_type(type);
go_non_zero_struct = type;
}
return go_non_zero_struct;
}
case ARRAY_TYPE:
{
tree element_type = non_zero_size_type(TREE_TYPE(type));
return build_array_type_nelts(element_type, 1);
}
default:
gcc_unreachable();
}
gcc_unreachable();
}
// Make a global variable.
Bvariable*
Gcc_backend::global_variable(const std::string& package_name,
const std::string& unique_prefix,
const std::string& name,
Btype* btype,
bool is_external,
bool is_hidden,
Location location)
{
tree type_tree = btype->get_tree();
if (type_tree == error_mark_node)
return this->error_variable();
// The GNU linker does not like dynamic variables with zero size.
if ((is_external || !is_hidden) && int_size_in_bytes(type_tree) == 0)
type_tree = this->non_zero_size_type(type_tree);
std::string var_name(package_name);
var_name.push_back('.');
var_name.append(name);
tree decl = build_decl(location.gcc_location(), VAR_DECL,
get_identifier_from_string(var_name),
type_tree);
if (is_external)
DECL_EXTERNAL(decl) = 1;
else
TREE_STATIC(decl) = 1;
if (!is_hidden)
{
TREE_PUBLIC(decl) = 1;
std::string asm_name(unique_prefix);
asm_name.push_back('.');
asm_name.append(var_name);
SET_DECL_ASSEMBLER_NAME(decl, get_identifier_from_string(asm_name));
}
TREE_USED(decl) = 1;
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
// Set the initial value of a global variable.
void
Gcc_backend::global_variable_set_init(Bvariable* var, Bexpression* expr)
{
tree expr_tree = expr->get_tree();
if (expr_tree == error_mark_node)
return;
gcc_assert(TREE_CONSTANT(expr_tree));
tree var_decl = var->get_tree();
if (var_decl == error_mark_node)
return;
DECL_INITIAL(var_decl) = expr_tree;
}
// Make a local variable.
Bvariable*
Gcc_backend::local_variable(Bfunction* function, const std::string& name,
Btype* btype, bool is_address_taken,
Location location)
{
tree type_tree = btype->get_tree();
if (type_tree == error_mark_node)
return this->error_variable();
tree decl = build_decl(location.gcc_location(), VAR_DECL,
get_identifier_from_string(name),
type_tree);
DECL_CONTEXT(decl) = function->get_tree();
TREE_USED(decl) = 1;
if (is_address_taken)
TREE_ADDRESSABLE(decl) = 1;
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
// Make a function parameter variable.
Bvariable*
Gcc_backend::parameter_variable(Bfunction* function, const std::string& name,
Btype* btype, bool is_address_taken,
Location location)
{
tree type_tree = btype->get_tree();
if (type_tree == error_mark_node)
return this->error_variable();
tree decl = build_decl(location.gcc_location(), PARM_DECL,
get_identifier_from_string(name),
type_tree);
DECL_CONTEXT(decl) = function->get_tree();
DECL_ARG_TYPE(decl) = type_tree;
TREE_USED(decl) = 1;
if (is_address_taken)
TREE_ADDRESSABLE(decl) = 1;
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
// Make a temporary variable.
Bvariable*
Gcc_backend::temporary_variable(Bfunction* function, Bblock* bblock,
Btype* btype, Bexpression* binit,
bool is_address_taken,
Location location,
Bstatement** pstatement)
{
tree type_tree = btype->get_tree();
tree init_tree = binit == NULL ? NULL_TREE : binit->get_tree();
if (type_tree == error_mark_node || init_tree == error_mark_node)
{
*pstatement = this->error_statement();
return this->error_variable();
}
tree var;
// We can only use create_tmp_var if the type is not addressable.
if (!TREE_ADDRESSABLE(type_tree))
var = create_tmp_var(type_tree, "GOTMP");
else
{
gcc_assert(bblock != NULL);
var = build_decl(location.gcc_location(), VAR_DECL,
create_tmp_var_name("GOTMP"),
type_tree);
DECL_ARTIFICIAL(var) = 1;
DECL_IGNORED_P(var) = 1;
TREE_USED(var) = 1;
// FIXME: Permitting function to be NULL here is a temporary
// measure until we have a proper representation of the init
// function.
if (function != NULL)
DECL_CONTEXT(var) = function->get_tree();
else
{
gcc_assert(current_function_decl != NULL_TREE);
DECL_CONTEXT(var) = current_function_decl;
}
// We have to add this variable to the BLOCK and the BIND_EXPR.
tree bind_tree = bblock->get_tree();
gcc_assert(TREE_CODE(bind_tree) == BIND_EXPR);
tree block_tree = BIND_EXPR_BLOCK(bind_tree);
gcc_assert(TREE_CODE(block_tree) == BLOCK);
DECL_CHAIN(var) = BLOCK_VARS(block_tree);
BLOCK_VARS(block_tree) = var;
BIND_EXPR_VARS(bind_tree) = BLOCK_VARS(block_tree);
}
if (init_tree != NULL_TREE)
DECL_INITIAL(var) = fold_convert_loc(location.gcc_location(), type_tree,
init_tree);
if (is_address_taken)
TREE_ADDRESSABLE(var) = 1;
*pstatement = this->make_statement(build1_loc(location.gcc_location(),
DECL_EXPR,
void_type_node, var));
return new Bvariable(var);
}
// Create a named immutable initialized data structure.
Bvariable*
Gcc_backend::immutable_struct(const std::string& name, bool, Btype* btype,
Location location)
{
tree type_tree = btype->get_tree();
if (type_tree == error_mark_node)
return this->error_variable();
gcc_assert(TREE_CODE(type_tree) == RECORD_TYPE);
tree decl = build_decl(location.gcc_location(), VAR_DECL,
get_identifier_from_string(name),
build_qualified_type(type_tree, TYPE_QUAL_CONST));
TREE_STATIC(decl) = 1;
TREE_READONLY(decl) = 1;
TREE_CONSTANT(decl) = 1;
TREE_USED(decl) = 1;
DECL_ARTIFICIAL(decl) = 1;
// We don't call rest_of_decl_compilation until we have the
// initializer.
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
// Set the initializer for a variable created by immutable_struct.
// This is where we finish compiling the variable.
void
Gcc_backend::immutable_struct_set_init(Bvariable* var, const std::string&,
bool is_common, Btype*,
Location,
Bexpression* initializer)
{
tree decl = var->get_tree();
tree init_tree = initializer->get_tree();
if (decl == error_mark_node || init_tree == error_mark_node)
return;
DECL_INITIAL(decl) = init_tree;
// We can't call make_decl_one_only until we set DECL_INITIAL.
if (!is_common)
TREE_PUBLIC(decl) = 1;
else
{
make_decl_one_only(decl, DECL_ASSEMBLER_NAME(decl));
resolve_unique_section(decl, 1, 0);
}
rest_of_decl_compilation(decl, 1, 0);
}
// Return a reference to an immutable initialized data structure
// defined in another package.
Bvariable*
Gcc_backend::immutable_struct_reference(const std::string& name, Btype* btype,
Location location)
{
tree type_tree = btype->get_tree();
if (type_tree == error_mark_node)
return this->error_variable();
gcc_assert(TREE_CODE(type_tree) == RECORD_TYPE);
tree decl = build_decl(location.gcc_location(), VAR_DECL,
get_identifier_from_string(name),
build_qualified_type(type_tree, TYPE_QUAL_CONST));
TREE_READONLY(decl) = 1;
TREE_CONSTANT(decl) = 1;
DECL_ARTIFICIAL(decl) = 1;
TREE_PUBLIC(decl) = 1;
DECL_EXTERNAL(decl) = 1;
go_preserve_from_gc(decl);
return new Bvariable(decl);
}
// Make a label.
Blabel*
Gcc_backend::label(Bfunction* function, const std::string& name,
Location location)
{
tree decl;
if (name.empty())
decl = create_artificial_label(location.gcc_location());
else
{
tree id = get_identifier_from_string(name);
decl = build_decl(location.gcc_location(), LABEL_DECL, id,
void_type_node);
DECL_CONTEXT(decl) = function->get_tree();
}
return new Blabel(decl);
}
// Make a statement which defines a label.
Bstatement*
Gcc_backend::label_definition_statement(Blabel* label)
{
tree lab = label->get_tree();
tree ret = fold_build1_loc(DECL_SOURCE_LOCATION(lab), LABEL_EXPR,
void_type_node, lab);
return this->make_statement(ret);
}
// Make a goto statement.
Bstatement*
Gcc_backend::goto_statement(Blabel* label, Location location)
{
tree lab = label->get_tree();
tree ret = fold_build1_loc(location.gcc_location(), GOTO_EXPR, void_type_node,
lab);
return this->make_statement(ret);
}
// Get the address of a label.
Bexpression*
Gcc_backend::label_address(Blabel* label, Location location)
{
tree lab = label->get_tree();
TREE_USED(lab) = 1;
TREE_ADDRESSABLE(lab) = 1;
tree ret = fold_convert_loc(location.gcc_location(), ptr_type_node,
build_fold_addr_expr_loc(location.gcc_location(),
lab));
return this->make_expression(ret);
}
// The single backend.
static Gcc_backend gcc_backend;
// Return the backend generator.
Backend*
go_get_backend()
{
return &gcc_backend;
}
// FIXME: Temporary functions while converting to the new backend
// interface.
Btype*
tree_to_type(tree t)
{
return new Btype(t);
}
Bexpression*
tree_to_expr(tree t)
{
return new Bexpression(t);
}
Bstatement*
tree_to_stat(tree t)
{
return new Bstatement(t);
}
Bfunction*
tree_to_function(tree t)
{
return new Bfunction(t);
}
Bblock*
tree_to_block(tree t)
{
gcc_assert(TREE_CODE(t) == BIND_EXPR);
return new Bblock(t);
}
tree
type_to_tree(Btype* bt)
{
return bt->get_tree();
}
tree
expr_to_tree(Bexpression* be)
{
return be->get_tree();
}
tree
stat_to_tree(Bstatement* bs)
{
return bs->get_tree();
}
tree
block_to_tree(Bblock* bb)
{
return bb->get_tree();
}
tree
var_to_tree(Bvariable* bv)
{
return bv->get_tree();
}