freebsd-skq/contrib/gcc/cp/cp-lang.c
2003-07-11 03:40:53 +00:00

339 lines
11 KiB
C

/* Language-dependent hooks for C++.
Copyright 2001, 2002 Free Software Foundation, Inc.
Contributed by Alexandre Oliva <aoliva@redhat.com>
This file is part of GNU CC.
GNU CC 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 2, or (at your option)
any later version.
GNU CC 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 GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "tree.h"
#include "cp-tree.h"
#include "c-common.h"
#include "toplev.h"
#include "langhooks.h"
#include "langhooks-def.h"
static HOST_WIDE_INT cxx_get_alias_set PARAMS ((tree));
static bool ok_to_generate_alias_set_for_type PARAMS ((tree));
static bool cxx_warn_unused_global_decl PARAMS ((tree));
static tree cp_expr_size PARAMS ((tree));
static bool cp_var_mod_type_p PARAMS ((tree));
#undef LANG_HOOKS_NAME
#define LANG_HOOKS_NAME "GNU C++"
#undef LANG_HOOKS_INIT
#define LANG_HOOKS_INIT cxx_init
#undef LANG_HOOKS_FINISH
#define LANG_HOOKS_FINISH cxx_finish
#undef LANG_HOOKS_CLEAR_BINDING_STACK
#define LANG_HOOKS_CLEAR_BINDING_STACK pop_everything
#undef LANG_HOOKS_INIT_OPTIONS
#define LANG_HOOKS_INIT_OPTIONS cxx_init_options
#undef LANG_HOOKS_DECODE_OPTION
#define LANG_HOOKS_DECODE_OPTION c_common_decode_option
#undef LANG_HOOKS_POST_OPTIONS
#define LANG_HOOKS_POST_OPTIONS c_common_post_options
#undef LANG_HOOKS_GET_ALIAS_SET
#define LANG_HOOKS_GET_ALIAS_SET cxx_get_alias_set
#undef LANG_HOOKS_EXPAND_CONSTANT
#define LANG_HOOKS_EXPAND_CONSTANT cplus_expand_constant
#undef LANG_HOOKS_EXPAND_EXPR
#define LANG_HOOKS_EXPAND_EXPR cxx_expand_expr
#undef LANG_HOOKS_SAFE_FROM_P
#define LANG_HOOKS_SAFE_FROM_P c_safe_from_p
#undef LANG_HOOKS_PARSE_FILE
#define LANG_HOOKS_PARSE_FILE c_common_parse_file
#undef LANG_HOOKS_DUP_LANG_SPECIFIC_DECL
#define LANG_HOOKS_DUP_LANG_SPECIFIC_DECL cxx_dup_lang_specific_decl
#undef LANG_HOOKS_UNSAVE_EXPR_NOW
#define LANG_HOOKS_UNSAVE_EXPR_NOW cxx_unsave_expr_now
#undef LANG_HOOKS_MAYBE_BUILD_CLEANUP
#define LANG_HOOKS_MAYBE_BUILD_CLEANUP cxx_maybe_build_cleanup
#undef LANG_HOOKS_TRUTHVALUE_CONVERSION
#define LANG_HOOKS_TRUTHVALUE_CONVERSION c_common_truthvalue_conversion
#undef LANG_HOOKS_INSERT_DEFAULT_ATTRIBUTES
#define LANG_HOOKS_INSERT_DEFAULT_ATTRIBUTES cxx_insert_default_attributes
#undef LANG_HOOKS_UNSAFE_FOR_REEVAL
#define LANG_HOOKS_UNSAFE_FOR_REEVAL c_common_unsafe_for_reeval
#undef LANG_HOOKS_SET_DECL_ASSEMBLER_NAME
#define LANG_HOOKS_SET_DECL_ASSEMBLER_NAME mangle_decl
#undef LANG_HOOKS_MARK_ADDRESSABLE
#define LANG_HOOKS_MARK_ADDRESSABLE cxx_mark_addressable
#undef LANG_HOOKS_PRINT_STATISTICS
#define LANG_HOOKS_PRINT_STATISTICS cxx_print_statistics
#undef LANG_HOOKS_PRINT_XNODE
#define LANG_HOOKS_PRINT_XNODE cxx_print_xnode
#undef LANG_HOOKS_PRINT_DECL
#define LANG_HOOKS_PRINT_DECL cxx_print_decl
#undef LANG_HOOKS_PRINT_TYPE
#define LANG_HOOKS_PRINT_TYPE cxx_print_type
#undef LANG_HOOKS_PRINT_IDENTIFIER
#define LANG_HOOKS_PRINT_IDENTIFIER cxx_print_identifier
#undef LANG_HOOKS_DECL_PRINTABLE_NAME
#define LANG_HOOKS_DECL_PRINTABLE_NAME cxx_printable_name
#undef LANG_HOOKS_PRINT_ERROR_FUNCTION
#define LANG_HOOKS_PRINT_ERROR_FUNCTION cxx_print_error_function
#undef LANG_HOOKS_WARN_UNUSED_GLOBAL_DECL
#define LANG_HOOKS_WARN_UNUSED_GLOBAL_DECL cxx_warn_unused_global_decl
#undef LANG_HOOKS_WRITE_GLOBALS
#define LANG_HOOKS_WRITE_GLOBALS lhd_do_nothing
#undef LANG_HOOKS_FUNCTION_INIT
#define LANG_HOOKS_FUNCTION_INIT cxx_push_function_context
#undef LANG_HOOKS_FUNCTION_FINAL
#define LANG_HOOKS_FUNCTION_FINAL cxx_pop_function_context
/* Attribute hooks. */
#undef LANG_HOOKS_COMMON_ATTRIBUTE_TABLE
#define LANG_HOOKS_COMMON_ATTRIBUTE_TABLE c_common_attribute_table
#undef LANG_HOOKS_FORMAT_ATTRIBUTE_TABLE
#define LANG_HOOKS_FORMAT_ATTRIBUTE_TABLE c_common_format_attribute_table
#undef LANG_HOOKS_ATTRIBUTE_TABLE
#define LANG_HOOKS_ATTRIBUTE_TABLE cxx_attribute_table
#undef LANG_HOOKS_TREE_INLINING_WALK_SUBTREES
#define LANG_HOOKS_TREE_INLINING_WALK_SUBTREES \
cp_walk_subtrees
#undef LANG_HOOKS_TREE_INLINING_CANNOT_INLINE_TREE_FN
#define LANG_HOOKS_TREE_INLINING_CANNOT_INLINE_TREE_FN \
cp_cannot_inline_tree_fn
#undef LANG_HOOKS_TREE_INLINING_ADD_PENDING_FN_DECLS
#define LANG_HOOKS_TREE_INLINING_ADD_PENDING_FN_DECLS \
cp_add_pending_fn_decls
#undef LANG_HOOKS_TREE_INLINING_TREE_CHAIN_MATTERS_P
#define LANG_HOOKS_TREE_INLINING_TREE_CHAIN_MATTERS_P \
cp_is_overload_p
#undef LANG_HOOKS_TREE_INLINING_AUTO_VAR_IN_FN_P
#define LANG_HOOKS_TREE_INLINING_AUTO_VAR_IN_FN_P \
cp_auto_var_in_fn_p
#undef LANG_HOOKS_TREE_INLINING_COPY_RES_DECL_FOR_INLINING
#define LANG_HOOKS_TREE_INLINING_COPY_RES_DECL_FOR_INLINING \
cp_copy_res_decl_for_inlining
#undef LANG_HOOKS_TREE_INLINING_ANON_AGGR_TYPE_P
#define LANG_HOOKS_TREE_INLINING_ANON_AGGR_TYPE_P anon_aggr_type_p
#undef LANG_HOOKS_TREE_INLINING_VAR_MOD_TYPE_P
#define LANG_HOOKS_TREE_INLINING_VAR_MOD_TYPE_P cp_var_mod_type_p
#undef LANG_HOOKS_TREE_INLINING_START_INLINING
#define LANG_HOOKS_TREE_INLINING_START_INLINING cp_start_inlining
#undef LANG_HOOKS_TREE_INLINING_END_INLINING
#define LANG_HOOKS_TREE_INLINING_END_INLINING cp_end_inlining
#undef LANG_HOOKS_TREE_DUMP_DUMP_TREE_FN
#define LANG_HOOKS_TREE_DUMP_DUMP_TREE_FN cp_dump_tree
#undef LANG_HOOKS_TREE_DUMP_TYPE_QUALS_FN
#define LANG_HOOKS_TREE_DUMP_TYPE_QUALS_FN cp_type_quals
#undef LANG_HOOKS_EXPR_SIZE
#define LANG_HOOKS_EXPR_SIZE cp_expr_size
#undef LANG_HOOKS_MAKE_TYPE
#define LANG_HOOKS_MAKE_TYPE cxx_make_type
#undef LANG_HOOKS_TYPE_FOR_MODE
#define LANG_HOOKS_TYPE_FOR_MODE c_common_type_for_mode
#undef LANG_HOOKS_TYPE_FOR_SIZE
#define LANG_HOOKS_TYPE_FOR_SIZE c_common_type_for_size
#undef LANG_HOOKS_SIGNED_TYPE
#define LANG_HOOKS_SIGNED_TYPE c_common_signed_type
#undef LANG_HOOKS_UNSIGNED_TYPE
#define LANG_HOOKS_UNSIGNED_TYPE c_common_unsigned_type
#undef LANG_HOOKS_SIGNED_OR_UNSIGNED_TYPE
#define LANG_HOOKS_SIGNED_OR_UNSIGNED_TYPE c_common_signed_or_unsigned_type
#undef LANG_HOOKS_INCOMPLETE_TYPE_ERROR
#define LANG_HOOKS_INCOMPLETE_TYPE_ERROR cxx_incomplete_type_error
#undef LANG_HOOKS_TYPE_PROMOTES_TO
#define LANG_HOOKS_TYPE_PROMOTES_TO cxx_type_promotes_to
/* Each front end provides its own hooks, for toplev.c. */
const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
/* Tree code classes. */
#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
const char tree_code_type[] = {
#include "tree.def"
'x',
#include "c-common.def"
'x',
#include "cp-tree.def"
};
#undef DEFTREECODE
/* Table indexed by tree code giving number of expression
operands beyond the fixed part of the node structure.
Not used for types or decls. */
#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
const unsigned char tree_code_length[] = {
#include "tree.def"
0,
#include "c-common.def"
0,
#include "cp-tree.def"
};
#undef DEFTREECODE
/* Names of tree components.
Used for printing out the tree and error messages. */
#define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
const char *const tree_code_name[] = {
#include "tree.def"
"@@dummy",
#include "c-common.def"
"@@dummy",
#include "cp-tree.def"
};
#undef DEFTREECODE
/* Check if a C++ type is safe for aliasing.
Return TRUE if T safe for aliasing FALSE otherwise. */
static bool
ok_to_generate_alias_set_for_type (t)
tree t;
{
if (TYPE_PTRMEMFUNC_P (t))
return true;
if (AGGREGATE_TYPE_P (t))
{
if ((TREE_CODE (t) == RECORD_TYPE) || (TREE_CODE (t) == UNION_TYPE))
{
tree fields;
/* Backend-created structs are safe. */
if (! CLASS_TYPE_P (t))
return true;
/* PODs are safe. */
if (! CLASSTYPE_NON_POD_P(t))
return true;
/* Classes with virtual baseclasses are not. */
if (TYPE_USES_VIRTUAL_BASECLASSES (t))
return false;
/* Recursively check the base classes. */
if (TYPE_BINFO (t) != NULL && TYPE_BINFO_BASETYPES (t) != NULL)
{
int i;
for (i = 0; i < TREE_VEC_LENGTH (TYPE_BINFO_BASETYPES (t)); i++)
{
tree binfo = TREE_VEC_ELT (TYPE_BINFO_BASETYPES (t), i);
if (!ok_to_generate_alias_set_for_type (BINFO_TYPE (binfo)))
return false;
}
}
/* Check all the fields. */
for (fields = TYPE_FIELDS (t); fields; fields = TREE_CHAIN (fields))
{
if (TREE_CODE (fields) != FIELD_DECL)
continue;
if (! ok_to_generate_alias_set_for_type (TREE_TYPE (fields)))
return false;
}
return true;
}
else if (TREE_CODE (t) == ARRAY_TYPE)
return ok_to_generate_alias_set_for_type (TREE_TYPE (t));
else
/* This should never happen, we dealt with all the aggregate
types that can appear in C++ above. */
abort ();
}
else
return true;
}
/* Special routine to get the alias set for C++. */
static HOST_WIDE_INT
cxx_get_alias_set (t)
tree t;
{
if (/* It's not yet safe to use alias sets for some classes in C++. */
!ok_to_generate_alias_set_for_type (t)
/* Nor is it safe to use alias sets for pointers-to-member
functions, due to the fact that there may be more than one
RECORD_TYPE type corresponding to the same pointer-to-member
type. */
|| TYPE_PTRMEMFUNC_P (t))
return 0;
return c_common_get_alias_set (t);
}
/* Called from check_global_declarations. */
static bool
cxx_warn_unused_global_decl (decl)
tree decl;
{
if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl))
return false;
if (DECL_IN_SYSTEM_HEADER (decl))
return false;
/* Const variables take the place of #defines in C++. */
if (TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl))
return false;
return true;
}
/* Langhook for expr_size: Tell the backend that the value of an expression
of non-POD class type does not include any tail padding; a derived class
might have allocated something there. */
static tree
cp_expr_size (exp)
tree exp;
{
if (CLASS_TYPE_P (TREE_TYPE (exp)))
{
/* The backend should not be interested in the size of an expression
of a type with both of these set; all copies of such types must go
through a constructor or assignment op. */
if (TYPE_HAS_COMPLEX_INIT_REF (TREE_TYPE (exp))
&& TYPE_HAS_COMPLEX_ASSIGN_REF (TREE_TYPE (exp))
/* But storing a CONSTRUCTOR isn't a copy. */
&& TREE_CODE (exp) != CONSTRUCTOR)
abort ();
/* This would be wrong for a type with virtual bases, but they are
caught by the abort above. */
return CLASSTYPE_SIZE_UNIT (TREE_TYPE (exp));
}
else
/* Use the default code. */
return lhd_expr_size (exp);
}
/* Returns true if T is a variably modified type, in the sense of C99.
This routine needs only check cases that cannot be handled by the
language-independent logic in tree-inline.c. */
static bool
cp_var_mod_type_p (tree type)
{
/* If TYPE is a pointer-to-member, it is variably modified if either
the class or the member are variably modified. */
if (TYPE_PTRMEM_P (type) || TYPE_PTRMEMFUNC_P (type))
return (variably_modified_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
|| variably_modified_type_p (TYPE_PTRMEM_POINTED_TO_TYPE (type)));
/* All other types are not variably modified. */
return false;
}