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425 lines
12 KiB
C
425 lines
12 KiB
C
/* Functions dealing with attribute handling, used by most front ends.
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Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
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2002, 2003 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "flags.h"
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#include "toplev.h"
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#include "output.h"
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#include "rtl.h"
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#include "ggc.h"
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#include "expr.h"
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#include "tm_p.h"
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#include "cpplib.h"
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#include "target.h"
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#include "langhooks.h"
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static void init_attributes (void);
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/* Table of the tables of attributes (common, language, format, machine)
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searched. */
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static const struct attribute_spec *attribute_tables[4];
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static bool attributes_initialized = false;
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/* Default empty table of attributes. */
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static const struct attribute_spec empty_attribute_table[] =
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{
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{ NULL, 0, 0, false, false, false, NULL }
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};
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/* Initialize attribute tables, and make some sanity checks
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if --enable-checking. */
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static void
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init_attributes (void)
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{
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size_t i;
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attribute_tables[0] = lang_hooks.common_attribute_table;
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attribute_tables[1] = lang_hooks.attribute_table;
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attribute_tables[2] = lang_hooks.format_attribute_table;
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attribute_tables[3] = targetm.attribute_table;
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/* Translate NULL pointers to pointers to the empty table. */
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for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)
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if (attribute_tables[i] == NULL)
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attribute_tables[i] = empty_attribute_table;
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#ifdef ENABLE_CHECKING
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/* Make some sanity checks on the attribute tables. */
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for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)
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{
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int j;
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for (j = 0; attribute_tables[i][j].name != NULL; j++)
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{
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/* The name must not begin and end with __. */
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const char *name = attribute_tables[i][j].name;
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int len = strlen (name);
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if (name[0] == '_' && name[1] == '_'
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&& name[len - 1] == '_' && name[len - 2] == '_')
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abort ();
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/* The minimum and maximum lengths must be consistent. */
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if (attribute_tables[i][j].min_length < 0)
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abort ();
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if (attribute_tables[i][j].max_length != -1
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&& (attribute_tables[i][j].max_length
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< attribute_tables[i][j].min_length))
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abort ();
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/* An attribute cannot require both a DECL and a TYPE. */
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if (attribute_tables[i][j].decl_required
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&& attribute_tables[i][j].type_required)
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abort ();
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/* If an attribute requires a function type, in particular
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it requires a type. */
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if (attribute_tables[i][j].function_type_required
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&& !attribute_tables[i][j].type_required)
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abort ();
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}
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}
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/* Check that each name occurs just once in each table. */
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for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)
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{
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int j, k;
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for (j = 0; attribute_tables[i][j].name != NULL; j++)
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for (k = j + 1; attribute_tables[i][k].name != NULL; k++)
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if (!strcmp (attribute_tables[i][j].name,
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attribute_tables[i][k].name))
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abort ();
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}
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/* Check that no name occurs in more than one table. */
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for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)
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{
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size_t j, k, l;
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for (j = i + 1; j < ARRAY_SIZE (attribute_tables); j++)
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for (k = 0; attribute_tables[i][k].name != NULL; k++)
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for (l = 0; attribute_tables[j][l].name != NULL; l++)
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if (!strcmp (attribute_tables[i][k].name,
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attribute_tables[j][l].name))
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abort ();
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}
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#endif
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attributes_initialized = true;
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}
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/* Process the attributes listed in ATTRIBUTES and install them in *NODE,
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which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL,
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it should be modified in place; if a TYPE, a copy should be created
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unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS. FLAGS gives further
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information, in the form of a bitwise OR of flags in enum attribute_flags
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from tree.h. Depending on these flags, some attributes may be
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returned to be applied at a later stage (for example, to apply
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a decl attribute to the declaration rather than to its type). */
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tree
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decl_attributes (tree *node, tree attributes, int flags)
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{
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tree a;
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tree returned_attrs = NULL_TREE;
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if (!attributes_initialized)
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init_attributes ();
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(*targetm.insert_attributes) (*node, &attributes);
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for (a = attributes; a; a = TREE_CHAIN (a))
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{
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tree name = TREE_PURPOSE (a);
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tree args = TREE_VALUE (a);
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tree *anode = node;
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const struct attribute_spec *spec = NULL;
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bool no_add_attrs = 0;
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tree fn_ptr_tmp = NULL_TREE;
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size_t i;
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for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)
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{
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int j;
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for (j = 0; attribute_tables[i][j].name != NULL; j++)
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{
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if (is_attribute_p (attribute_tables[i][j].name, name))
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{
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spec = &attribute_tables[i][j];
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break;
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}
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}
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if (spec != NULL)
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break;
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}
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if (spec == NULL)
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{
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warning ("`%s' attribute directive ignored",
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IDENTIFIER_POINTER (name));
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continue;
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}
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else if (list_length (args) < spec->min_length
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|| (spec->max_length >= 0
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&& list_length (args) > spec->max_length))
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{
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error ("wrong number of arguments specified for `%s' attribute",
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IDENTIFIER_POINTER (name));
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continue;
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}
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if (spec->decl_required && !DECL_P (*anode))
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{
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if (flags & ((int) ATTR_FLAG_DECL_NEXT
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| (int) ATTR_FLAG_FUNCTION_NEXT
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| (int) ATTR_FLAG_ARRAY_NEXT))
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{
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/* Pass on this attribute to be tried again. */
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returned_attrs = tree_cons (name, args, returned_attrs);
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continue;
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}
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else
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{
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warning ("`%s' attribute does not apply to types",
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IDENTIFIER_POINTER (name));
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continue;
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}
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}
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/* If we require a type, but were passed a decl, set up to make a
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new type and update the one in the decl. ATTR_FLAG_TYPE_IN_PLACE
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would have applied if we'd been passed a type, but we cannot modify
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the decl's type in place here. */
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if (spec->type_required && DECL_P (*anode))
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{
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anode = &TREE_TYPE (*anode);
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flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE;
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}
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if (spec->function_type_required && TREE_CODE (*anode) != FUNCTION_TYPE
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&& TREE_CODE (*anode) != METHOD_TYPE)
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{
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if (TREE_CODE (*anode) == POINTER_TYPE
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&& (TREE_CODE (TREE_TYPE (*anode)) == FUNCTION_TYPE
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|| TREE_CODE (TREE_TYPE (*anode)) == METHOD_TYPE))
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{
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/* OK, this is a bit convoluted. We can't just make a copy
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of the pointer type and modify its TREE_TYPE, because if
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we change the attributes of the target type the pointer
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type needs to have a different TYPE_MAIN_VARIANT. So we
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pull out the target type now, frob it as appropriate, and
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rebuild the pointer type later.
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This would all be simpler if attributes were part of the
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declarator, grumble grumble. */
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fn_ptr_tmp = TREE_TYPE (*anode);
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anode = &fn_ptr_tmp;
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flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE;
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}
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else if (flags & (int) ATTR_FLAG_FUNCTION_NEXT)
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{
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/* Pass on this attribute to be tried again. */
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returned_attrs = tree_cons (name, args, returned_attrs);
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continue;
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}
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if (TREE_CODE (*anode) != FUNCTION_TYPE
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&& TREE_CODE (*anode) != METHOD_TYPE)
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{
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warning ("`%s' attribute only applies to function types",
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IDENTIFIER_POINTER (name));
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continue;
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}
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}
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if (spec->handler != NULL)
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returned_attrs = chainon ((*spec->handler) (anode, name, args,
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flags, &no_add_attrs),
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returned_attrs);
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/* Layout the decl in case anything changed. */
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if (spec->type_required && DECL_P (*node)
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&& (TREE_CODE (*node) == VAR_DECL
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|| TREE_CODE (*node) == PARM_DECL
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|| TREE_CODE (*node) == RESULT_DECL))
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{
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/* Force a recalculation of mode and size. */
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DECL_MODE (*node) = VOIDmode;
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DECL_SIZE (*node) = 0;
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if (!DECL_USER_ALIGN (*node))
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DECL_ALIGN (*node) = 0;
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layout_decl (*node, 0);
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}
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if (!no_add_attrs)
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{
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tree old_attrs;
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tree a;
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if (DECL_P (*anode))
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old_attrs = DECL_ATTRIBUTES (*anode);
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else
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old_attrs = TYPE_ATTRIBUTES (*anode);
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for (a = lookup_attribute (spec->name, old_attrs);
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a != NULL_TREE;
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a = lookup_attribute (spec->name, TREE_CHAIN (a)))
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{
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if (simple_cst_equal (TREE_VALUE (a), args) == 1)
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break;
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}
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if (a == NULL_TREE)
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{
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/* This attribute isn't already in the list. */
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if (DECL_P (*anode))
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DECL_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs);
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else if (flags & (int) ATTR_FLAG_TYPE_IN_PLACE)
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TYPE_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs);
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else
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*anode = build_type_attribute_variant (*anode,
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tree_cons (name, args,
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old_attrs));
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}
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}
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if (fn_ptr_tmp)
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{
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/* Rebuild the function pointer type and put it in the
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appropriate place. */
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fn_ptr_tmp = build_pointer_type (fn_ptr_tmp);
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if (DECL_P (*node))
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TREE_TYPE (*node) = fn_ptr_tmp;
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else if (TREE_CODE (*node) == POINTER_TYPE)
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*node = fn_ptr_tmp;
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else
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abort ();
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}
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}
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return returned_attrs;
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}
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/* Split SPECS_ATTRS, a list of declspecs and prefix attributes, into two
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lists. SPECS_ATTRS may also be just a typespec (eg: RECORD_TYPE).
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The head of the declspec list is stored in DECLSPECS.
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The head of the attribute list is stored in PREFIX_ATTRIBUTES.
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Note that attributes in SPECS_ATTRS are stored in the TREE_PURPOSE of
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the list elements. We drop the containing TREE_LIST nodes and link the
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resulting attributes together the way decl_attributes expects them. */
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void
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split_specs_attrs (tree specs_attrs, tree *declspecs, tree *prefix_attributes)
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{
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tree t, s, a, next, specs, attrs;
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/* This can happen after an __extension__ in pedantic mode. */
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if (specs_attrs != NULL_TREE
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&& TREE_CODE (specs_attrs) == INTEGER_CST)
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{
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*declspecs = NULL_TREE;
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*prefix_attributes = NULL_TREE;
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return;
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}
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/* This can happen in c++ (eg: decl: typespec initdecls ';'). */
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if (specs_attrs != NULL_TREE
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&& TREE_CODE (specs_attrs) != TREE_LIST)
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{
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*declspecs = specs_attrs;
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*prefix_attributes = NULL_TREE;
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return;
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}
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/* Remember to keep the lists in the same order, element-wise. */
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specs = s = NULL_TREE;
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attrs = a = NULL_TREE;
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for (t = specs_attrs; t; t = next)
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{
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next = TREE_CHAIN (t);
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/* Declspecs have a non-NULL TREE_VALUE. */
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if (TREE_VALUE (t) != NULL_TREE)
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{
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if (specs == NULL_TREE)
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specs = s = t;
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else
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{
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TREE_CHAIN (s) = t;
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s = t;
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}
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}
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/* The TREE_PURPOSE may also be empty in the case of
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__attribute__(()). */
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else if (TREE_PURPOSE (t) != NULL_TREE)
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{
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if (attrs == NULL_TREE)
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attrs = a = TREE_PURPOSE (t);
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else
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{
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TREE_CHAIN (a) = TREE_PURPOSE (t);
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a = TREE_PURPOSE (t);
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}
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/* More attrs can be linked here, move A to the end. */
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while (TREE_CHAIN (a) != NULL_TREE)
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a = TREE_CHAIN (a);
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}
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}
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/* Terminate the lists. */
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if (s != NULL_TREE)
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TREE_CHAIN (s) = NULL_TREE;
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if (a != NULL_TREE)
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TREE_CHAIN (a) = NULL_TREE;
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/* All done. */
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*declspecs = specs;
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*prefix_attributes = attrs;
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}
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/* Strip attributes from SPECS_ATTRS, a list of declspecs and attributes.
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This function is used by the parser when a rule will accept attributes
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in a particular position, but we don't want to support that just yet.
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A warning is issued for every ignored attribute. */
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tree
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strip_attrs (tree specs_attrs)
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{
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tree specs, attrs;
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split_specs_attrs (specs_attrs, &specs, &attrs);
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while (attrs)
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{
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warning ("`%s' attribute ignored",
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IDENTIFIER_POINTER (TREE_PURPOSE (attrs)));
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attrs = TREE_CHAIN (attrs);
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}
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return specs;
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}
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