486 lines
15 KiB
C
486 lines
15 KiB
C
/* 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, 2007, 2008, 2009, 2010
|
||
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 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
|
||
<http://www.gnu.org/licenses/>. */
|
||
|
||
#include "config.h"
|
||
#include "system.h"
|
||
#include "coretypes.h"
|
||
#include "tm.h"
|
||
#include "tree.h"
|
||
#include "flags.h"
|
||
#include "diagnostic-core.h"
|
||
#include "ggc.h"
|
||
#include "tm_p.h"
|
||
#include "cpplib.h"
|
||
#include "target.h"
|
||
#include "langhooks.h"
|
||
#include "hashtab.h"
|
||
#include "plugin.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];
|
||
|
||
/* Hashtable mapping names (represented as substrings) to attribute specs. */
|
||
static htab_t attribute_hash;
|
||
|
||
/* Substring representation. */
|
||
|
||
struct substring
|
||
{
|
||
const char *str;
|
||
int length;
|
||
};
|
||
|
||
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, false }
|
||
};
|
||
|
||
/* Return base name of the attribute. Ie '__attr__' is turned into 'attr'.
|
||
To avoid need for copying, we simply return length of the string. */
|
||
|
||
static void
|
||
extract_attribute_substring (struct substring *str)
|
||
{
|
||
if (str->length > 4 && str->str[0] == '_' && str->str[1] == '_'
|
||
&& str->str[str->length - 1] == '_' && str->str[str->length - 2] == '_')
|
||
{
|
||
str->length -= 4;
|
||
str->str += 2;
|
||
}
|
||
}
|
||
|
||
/* Simple hash function to avoid need to scan whole string. */
|
||
|
||
static inline hashval_t
|
||
substring_hash (const char *str, int l)
|
||
{
|
||
return str[0] + str[l - 1] * 256 + l * 65536;
|
||
}
|
||
|
||
/* Used for attribute_hash. */
|
||
|
||
static hashval_t
|
||
hash_attr (const void *p)
|
||
{
|
||
const struct attribute_spec *const spec = (const struct attribute_spec *) p;
|
||
const int l = strlen (spec->name);
|
||
|
||
return substring_hash (spec->name, l);
|
||
}
|
||
|
||
/* Used for attribute_hash. */
|
||
|
||
static int
|
||
eq_attr (const void *p, const void *q)
|
||
{
|
||
const struct attribute_spec *const spec = (const struct attribute_spec *) p;
|
||
const struct substring *const str = (const struct substring *) q;
|
||
|
||
return (!strncmp (spec->name, str->str, str->length) && !spec->name[str->length]);
|
||
}
|
||
|
||
/* Initialize attribute tables, and make some sanity checks
|
||
if --enable-checking. */
|
||
|
||
static void
|
||
init_attributes (void)
|
||
{
|
||
size_t i;
|
||
int k;
|
||
|
||
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
|
||
|
||
attribute_hash = htab_create (200, hash_attr, eq_attr, NULL);
|
||
for (i = 0; i < ARRAY_SIZE (attribute_tables); i++)
|
||
for (k = 0; attribute_tables[i][k].name != NULL; k++)
|
||
{
|
||
register_attribute (&attribute_tables[i][k]);
|
||
}
|
||
invoke_plugin_callbacks (PLUGIN_ATTRIBUTES, NULL);
|
||
attributes_initialized = true;
|
||
}
|
||
|
||
/* Insert a single ATTR into the attribute table. */
|
||
|
||
void
|
||
register_attribute (const struct attribute_spec *attr)
|
||
{
|
||
struct substring str;
|
||
void **slot;
|
||
|
||
str.str = attr->name;
|
||
str.length = strlen (str.str);
|
||
|
||
/* Attribute names in the table must be in the form 'text' and not
|
||
in the form '__text__'. */
|
||
gcc_assert (str.length > 0 && str.str[0] != '_');
|
||
|
||
slot = htab_find_slot_with_hash (attribute_hash, &str,
|
||
substring_hash (str.str, str.length),
|
||
INSERT);
|
||
gcc_assert (!*slot);
|
||
*slot = (void *) CONST_CAST (struct attribute_spec *, attr);
|
||
}
|
||
|
||
/* Return the spec for the attribute named NAME. */
|
||
|
||
const struct attribute_spec *
|
||
lookup_attribute_spec (const_tree name)
|
||
{
|
||
struct substring attr;
|
||
|
||
attr.str = IDENTIFIER_POINTER (name);
|
||
attr.length = IDENTIFIER_LENGTH (name);
|
||
extract_attribute_substring (&attr);
|
||
return (const struct attribute_spec *)
|
||
htab_find_with_hash (attribute_hash, &attr,
|
||
substring_hash (attr.str, attr.length));
|
||
}
|
||
|
||
/* 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 (TREE_TYPE (*node) == error_mark_node)
|
||
return NULL_TREE;
|
||
|
||
if (!attributes_initialized)
|
||
init_attributes ();
|
||
|
||
/* If this is a function and the user used #pragma GCC optimize, add the
|
||
options to the attribute((optimize(...))) list. */
|
||
if (TREE_CODE (*node) == FUNCTION_DECL && current_optimize_pragma)
|
||
{
|
||
tree cur_attr = lookup_attribute ("optimize", attributes);
|
||
tree opts = copy_list (current_optimize_pragma);
|
||
|
||
if (! cur_attr)
|
||
attributes
|
||
= tree_cons (get_identifier ("optimize"), opts, attributes);
|
||
else
|
||
TREE_VALUE (cur_attr) = chainon (opts, TREE_VALUE (cur_attr));
|
||
}
|
||
|
||
if (TREE_CODE (*node) == FUNCTION_DECL
|
||
&& optimization_current_node != optimization_default_node
|
||
&& !DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node))
|
||
DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node) = optimization_current_node;
|
||
|
||
/* If this is a function and the user used #pragma GCC target, add the
|
||
options to the attribute((target(...))) list. */
|
||
if (TREE_CODE (*node) == FUNCTION_DECL
|
||
&& current_target_pragma
|
||
&& targetm.target_option.valid_attribute_p (*node, NULL_TREE,
|
||
current_target_pragma, 0))
|
||
{
|
||
tree cur_attr = lookup_attribute ("target", attributes);
|
||
tree opts = copy_list (current_target_pragma);
|
||
|
||
if (! cur_attr)
|
||
attributes = tree_cons (get_identifier ("target"), opts, attributes);
|
||
else
|
||
TREE_VALUE (cur_attr) = chainon (opts, TREE_VALUE (cur_attr));
|
||
}
|
||
|
||
/* A "naked" function attribute implies "noinline" and "noclone" for
|
||
those targets that support it. */
|
||
if (TREE_CODE (*node) == FUNCTION_DECL
|
||
&& attributes
|
||
&& lookup_attribute_spec (get_identifier ("naked"))
|
||
&& lookup_attribute ("naked", attributes) != NULL)
|
||
{
|
||
if (lookup_attribute ("noinline", attributes) == NULL)
|
||
attributes = tree_cons (get_identifier ("noinline"), NULL, attributes);
|
||
|
||
if (lookup_attribute ("noclone", attributes) == NULL)
|
||
attributes = tree_cons (get_identifier ("noclone"), NULL, 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 = lookup_attribute_spec (name);
|
||
bool no_add_attrs = 0;
|
||
int fn_ptr_quals = 0;
|
||
tree fn_ptr_tmp = NULL_TREE;
|
||
|
||
if (spec == NULL)
|
||
{
|
||
warning (OPT_Wattributes, "%qE attribute directive ignored",
|
||
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 %qE attribute",
|
||
name);
|
||
continue;
|
||
}
|
||
gcc_assert (is_attribute_p (spec->name, name));
|
||
|
||
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, "%qE attribute does not apply to types",
|
||
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);
|
||
/* Allow ATTR_FLAG_TYPE_IN_PLACE for the type's naming decl. */
|
||
if (!(TREE_CODE (*anode) == TYPE_DECL
|
||
&& *anode == TYPE_NAME (TYPE_MAIN_VARIANT
|
||
(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);
|
||
fn_ptr_quals = TYPE_QUALS (*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,
|
||
"%qE attribute only applies to function types",
|
||
name);
|
||
continue;
|
||
}
|
||
}
|
||
|
||
if (TYPE_P (*anode)
|
||
&& (flags & (int) ATTR_FLAG_TYPE_IN_PLACE)
|
||
&& TYPE_SIZE (*anode) != NULL_TREE)
|
||
{
|
||
warning (OPT_Wattributes, "type attributes ignored after type is already defined");
|
||
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 (fn_ptr_quals)
|
||
fn_ptr_tmp = build_qualified_type (fn_ptr_tmp, fn_ptr_quals);
|
||
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;
|
||
}
|