/* 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 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 cxx_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_SAFE_FROM_P
#define LANG_HOOKS_SAFE_FROM_P c_safe_from_p
#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_SET_YYDEBUG
#define LANG_HOOKS_SET_YYDEBUG cxx_set_yydebug

#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

/* Each front end provides its own hooks, for toplev.c.  */
const struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;

/* Special routine to get the alias set for C++.  */

static HOST_WIDE_INT
cxx_get_alias_set (t)
     tree t;
{
  /* It's not yet safe to use alias sets for classes in C++ because
     the TYPE_FIELDs list for a class doesn't mention base classes.  */
  if (AGGREGATE_TYPE_P (t))
    return 0;

  return c_common_get_alias_set (t);
}

/* 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)))
    {
      /* This would be wrong for a type with virtual bases, but they should
	 not get here.  */
      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;
}