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/* Functions dealing with attribute handling, used by most front ends.

   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,

   2002, 2003, 2004, 2005 Free Software Foundation, Inc.

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 2, 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 COPYING.  If not, write to the Free

Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301, USA.  */

#include "config.h"

#include "system.h"

#include "coretypes.h"

#include "tm.h"

#include "tree.h"

#include "flags.h"

#include "toplev.h"

#include "output.h"

#include "rtl.h"

#include "ggc.h"

#include "tm_p.h"

#include "cpplib.h"

#include "target.h"

#include "langhooks.h"

static void init_attributes (void);

/* Table of the tables of attributes (common, language, format, machine)

   searched.  */

static const struct attribute_spec *attribute_tables[4];

static bool attributes_initialized = false;

/* Default empty table of attributes.  */

static const struct attribute_spec empty_attribute_table[] =

{

  { NULL, 0, 0, false, false, false, NULL }

};

/* Initialize attribute tables, and make some sanity checks

   if --enable-checking.  */

static void

init_attributes (void)

{

  size_t i;

  attribute_tables[0] = lang_hooks.common_attribute_table;

  attribute_tables[1] = lang_hooks.attribute_table;

  attribute_tables[2] = lang_hooks.format_attribute_table;

  attribute_tables[3] = targetm.attribute_table;

  /* Translate NULL pointers to pointers to the empty table.  */

  for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)

    if (attribute_tables[i] == NULL)

      attribute_tables[i] = empty_attribute_table;

#ifdef ENABLE_CHECKING

  /* Make some sanity checks on the attribute tables.  */

  for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)

    {

      int j;

      for (j = 0; attribute_tables[i][j].name != NULL; j++)

        {

          /* The name must not begin and end with __.  */

          const char *name = attribute_tables[i][j].name;

          int len = strlen (name);

          gcc_assert (!(name[0] == '_' && name[1] == '_'

                        && name[len - 1] == '_' && name[len - 2] == '_'));

          /* The minimum and maximum lengths must be consistent.  */

          gcc_assert (attribute_tables[i][j].min_length >= 0);

          gcc_assert (attribute_tables[i][j].max_length == -1

                      || (attribute_tables[i][j].max_length

                          >= attribute_tables[i][j].min_length));

          /* An attribute cannot require both a DECL and a TYPE.  */

          gcc_assert (!attribute_tables[i][j].decl_required

                      || !attribute_tables[i][j].type_required);

          /* If an attribute requires a function type, in particular

             it requires a type.  */

          gcc_assert (!attribute_tables[i][j].function_type_required

                      || attribute_tables[i][j].type_required);

        }

    }

  /* Check that each name occurs just once in each table.  */

  for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)

    {

      int j, k;

      for (j = 0; attribute_tables[i][j].name != NULL; j++)

        for (k = j + 1; attribute_tables[i][k].name != NULL; k++)

          gcc_assert (strcmp (attribute_tables[i][j].name,

                              attribute_tables[i][k].name));

    }

  /* Check that no name occurs in more than one table.  */

  for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)

    {

      size_t j, k, l;

      for (j = i + 1; j < ARRAY_SIZE (attribute_tables); j++)

        for (k = 0; attribute_tables[i][k].name != NULL; k++)

          for (l = 0; attribute_tables[j][l].name != NULL; l++)

            gcc_assert (strcmp (attribute_tables[i][k].name,

                                attribute_tables[j][l].name));

    }

#endif

  attributes_initialized = true;

}

/* Process the attributes listed in ATTRIBUTES and install them in *NODE,

   which is either a DECL (including a TYPE_DECL) or a TYPE.  If a DECL,

   it should be modified in place; if a TYPE, a copy should be created

   unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS.  FLAGS gives further

   information, in the form of a bitwise OR of flags in enum attribute_flags

   from tree.h.  Depending on these flags, some attributes may be

   returned to be applied at a later stage (for example, to apply

   a decl attribute to the declaration rather than to its type).  */

tree

decl_attributes (tree *node, tree attributes, int flags)

{

  tree a;

  tree returned_attrs = NULL_TREE;

  if (!attributes_initialized)

    init_attributes ();

  targetm.insert_attributes (*node, &attributes);

  for (a = attributes; a; a = TREE_CHAIN (a))

    {

      tree name = TREE_PURPOSE (a);

      tree args = TREE_VALUE (a);

      tree *anode = node;

      const struct attribute_spec *spec = NULL;

      bool no_add_attrs = 0;

      tree fn_ptr_tmp = NULL_TREE;

      size_t i;

      for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)

        {

          int j;

          for (j = 0; attribute_tables[i][j].name != NULL; j++)

            {

              if (is_attribute_p (attribute_tables[i][j].name, name))

                {

                  spec = &attribute_tables[i][j];

                  break;

                }

            }

          if (spec != NULL)

            break;

        }

      if (spec == NULL)

        {

          warning (OPT_Wattributes, "%qs attribute directive ignored",

                   IDENTIFIER_POINTER (name));

          continue;

        }

      else if (list_length (args) < spec->min_length

               || (spec->max_length >= 0

                   && list_length (args) > spec->max_length))

        {

          error ("wrong number of arguments specified for %qs attribute",

                 IDENTIFIER_POINTER (name));

          continue;

        }

      if (spec->decl_required && !DECL_P (*anode))

        {

          if (flags & ((int) ATTR_FLAG_DECL_NEXT

                       | (int) ATTR_FLAG_FUNCTION_NEXT

                       | (int) ATTR_FLAG_ARRAY_NEXT))

            {

              /* Pass on this attribute to be tried again.  */

              returned_attrs = tree_cons (name, args, returned_attrs);

              continue;

            }

          else

            {

              warning (OPT_Wattributes, "%qs attribute does not apply to types",

                       IDENTIFIER_POINTER (name));

              continue;

            }

        }

      /* If we require a type, but were passed a decl, set up to make a

         new type and update the one in the decl.  ATTR_FLAG_TYPE_IN_PLACE

         would have applied if we'd been passed a type, but we cannot modify

         the decl's type in place here.  */

      if (spec->type_required && DECL_P (*anode))

        {

          anode = &TREE_TYPE (*anode);

          flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE;

        }

      if (spec->function_type_required && TREE_CODE (*anode) != FUNCTION_TYPE

          && TREE_CODE (*anode) != METHOD_TYPE)

        {

          if (TREE_CODE (*anode) == POINTER_TYPE

              && (TREE_CODE (TREE_TYPE (*anode)) == FUNCTION_TYPE

                  || TREE_CODE (TREE_TYPE (*anode)) == METHOD_TYPE))

            {

              /* OK, this is a bit convoluted.  We can't just make a copy

                 of the pointer type and modify its TREE_TYPE, because if

                 we change the attributes of the target type the pointer

                 type needs to have a different TYPE_MAIN_VARIANT.  So we

                 pull out the target type now, frob it as appropriate, and

                 rebuild the pointer type later.

                 This would all be simpler if attributes were part of the

                 declarator, grumble grumble.  */

              fn_ptr_tmp = TREE_TYPE (*anode);

              anode = &fn_ptr_tmp;

              flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE;

            }

          else if (flags & (int) ATTR_FLAG_FUNCTION_NEXT)

            {

              /* Pass on this attribute to be tried again.  */

              returned_attrs = tree_cons (name, args, returned_attrs);

              continue;

            }

          if (TREE_CODE (*anode) != FUNCTION_TYPE

              && TREE_CODE (*anode) != METHOD_TYPE)

            {

              warning (OPT_Wattributes,

                       "%qs attribute only applies to function types",

                       IDENTIFIER_POINTER (name));

              continue;

            }

        }

      if (spec->handler != NULL)

        returned_attrs = chainon ((*spec->handler) (anode, name, args,

                                                    flags, &no_add_attrs),

                                  returned_attrs);

      /* Layout the decl in case anything changed.  */

      if (spec->type_required && DECL_P (*node)

          && (TREE_CODE (*node) == VAR_DECL

              || TREE_CODE (*node) == PARM_DECL

              || TREE_CODE (*node) == RESULT_DECL))

        relayout_decl (*node);

      if (!no_add_attrs)

        {

          tree old_attrs;

          tree a;

          if (DECL_P (*anode))

            old_attrs = DECL_ATTRIBUTES (*anode);

          else

            old_attrs = TYPE_ATTRIBUTES (*anode);

          for (a = lookup_attribute (spec->name, old_attrs);

               a != NULL_TREE;

               a = lookup_attribute (spec->name, TREE_CHAIN (a)))

            {

              if (simple_cst_equal (TREE_VALUE (a), args) == 1)

                break;

            }

          if (a == NULL_TREE)

            {

              /* This attribute isn't already in the list.  */

              if (DECL_P (*anode))

                DECL_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs);

              else if (flags & (int) ATTR_FLAG_TYPE_IN_PLACE)

                {

                  TYPE_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs);

                  /* If this is the main variant, also push the attributes

                     out to the other variants.  */

                  if (*anode == TYPE_MAIN_VARIANT (*anode))

                    {

                      tree variant;

                      for (variant = *anode; variant;

                           variant = TYPE_NEXT_VARIANT (variant))

                        {

                          if (TYPE_ATTRIBUTES (variant) == old_attrs)

                            TYPE_ATTRIBUTES (variant)

                              = TYPE_ATTRIBUTES (*anode);

                          else if (!lookup_attribute

                                   (spec->name, TYPE_ATTRIBUTES (variant)))

                            TYPE_ATTRIBUTES (variant) = tree_cons

                              (name, args, TYPE_ATTRIBUTES (variant));

                        }

                    }

                }

              else

                *anode = build_type_attribute_variant (*anode,

                                                       tree_cons (name, args,

                                                                  old_attrs));

            }

        }

      if (fn_ptr_tmp)

        {

          /* Rebuild the function pointer type and put it in the

             appropriate place.  */

          fn_ptr_tmp = build_pointer_type (fn_ptr_tmp);

          if (DECL_P (*node))

            TREE_TYPE (*node) = fn_ptr_tmp;

          else

            {

              gcc_assert (TREE_CODE (*node) == POINTER_TYPE);

              *node = fn_ptr_tmp;

            }

        }

    }

  return returned_attrs;

}