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e3f6ce11 | 1 | /* Functions dealing with attribute handling, used by most front ends. |
80fabb90 | 2 | Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, |
7cf0dbf3 | 3 | 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010 |
4 | Free Software Foundation, Inc. | |
e3f6ce11 | 5 | |
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 10 | Software Foundation; either version 3, or (at your option) any later |
e3f6ce11 | 11 | version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
e3f6ce11 | 21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
805e22b2 | 24 | #include "coretypes.h" |
25 | #include "tm.h" | |
e3f6ce11 | 26 | #include "tree.h" |
27 | #include "flags.h" | |
0b205f4c | 28 | #include "diagnostic-core.h" |
e3f6ce11 | 29 | #include "ggc.h" |
e3f6ce11 | 30 | #include "tm_p.h" |
e3f6ce11 | 31 | #include "cpplib.h" |
32 | #include "target.h" | |
26ca6c20 | 33 | #include "langhooks.h" |
5b634bfa | 34 | #include "hashtab.h" |
e3fced1a | 35 | #include "plugin.h" |
e3f6ce11 | 36 | |
aecda0d6 | 37 | static void init_attributes (void); |
e3f6ce11 | 38 | |
f8e93a2e | 39 | /* Table of the tables of attributes (common, language, format, machine) |
e3f6ce11 | 40 | searched. */ |
41 | static const struct attribute_spec *attribute_tables[4]; | |
42 | ||
5b634bfa | 43 | /* Hashtable mapping names (represented as substrings) to attribute specs. */ |
44 | static htab_t attribute_hash; | |
45 | ||
46 | /* Substring representation. */ | |
47 | ||
48 | struct substring | |
49 | { | |
50 | const char *str; | |
51 | int length; | |
52 | }; | |
53 | ||
e3f6ce11 | 54 | static bool attributes_initialized = false; |
55 | ||
e3f6ce11 | 56 | /* Default empty table of attributes. */ |
5b634bfa | 57 | |
e3f6ce11 | 58 | static const struct attribute_spec empty_attribute_table[] = |
59 | { | |
60 | { NULL, 0, 0, false, false, false, NULL } | |
61 | }; | |
62 | ||
5b634bfa | 63 | /* Return base name of the attribute. Ie '__attr__' is turned into 'attr'. |
64 | To avoid need for copying, we simply return length of the string. */ | |
65 | ||
66 | static void | |
67 | extract_attribute_substring (struct substring *str) | |
68 | { | |
69 | if (str->length > 4 && str->str[0] == '_' && str->str[1] == '_' | |
70 | && str->str[str->length - 1] == '_' && str->str[str->length - 2] == '_') | |
71 | { | |
72 | str->length -= 4; | |
73 | str->str += 2; | |
74 | } | |
75 | } | |
76 | ||
77 | /* Simple hash function to avoid need to scan whole string. */ | |
78 | ||
79 | static inline hashval_t | |
80 | substring_hash (const char *str, int l) | |
81 | { | |
82 | return str[0] + str[l - 1] * 256 + l * 65536; | |
83 | } | |
84 | ||
85 | /* Used for attribute_hash. */ | |
86 | ||
87 | static hashval_t | |
88 | hash_attr (const void *p) | |
89 | { | |
b7bf20db | 90 | const struct attribute_spec *const spec = (const struct attribute_spec *) p; |
91 | const int l = strlen (spec->name); | |
5b634bfa | 92 | |
93 | return substring_hash (spec->name, l); | |
94 | } | |
95 | ||
96 | /* Used for attribute_hash. */ | |
97 | ||
98 | static int | |
99 | eq_attr (const void *p, const void *q) | |
100 | { | |
b7bf20db | 101 | const struct attribute_spec *const spec = (const struct attribute_spec *) p; |
102 | const struct substring *const str = (const struct substring *) q; | |
5b634bfa | 103 | |
104 | return (!strncmp (spec->name, str->str, str->length) && !spec->name[str->length]); | |
105 | } | |
106 | ||
e3f6ce11 | 107 | /* Initialize attribute tables, and make some sanity checks |
108 | if --enable-checking. */ | |
109 | ||
110 | static void | |
aecda0d6 | 111 | init_attributes (void) |
e3f6ce11 | 112 | { |
3585dac7 | 113 | size_t i; |
5b634bfa | 114 | int k; |
e3f6ce11 | 115 | |
f8e93a2e | 116 | attribute_tables[0] = lang_hooks.common_attribute_table; |
117 | attribute_tables[1] = lang_hooks.attribute_table; | |
118 | attribute_tables[2] = lang_hooks.format_attribute_table; | |
e3f6ce11 | 119 | attribute_tables[3] = targetm.attribute_table; |
120 | ||
f8e93a2e | 121 | /* Translate NULL pointers to pointers to the empty table. */ |
122 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) | |
123 | if (attribute_tables[i] == NULL) | |
124 | attribute_tables[i] = empty_attribute_table; | |
125 | ||
e3f6ce11 | 126 | #ifdef ENABLE_CHECKING |
127 | /* Make some sanity checks on the attribute tables. */ | |
3585dac7 | 128 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) |
e3f6ce11 | 129 | { |
130 | int j; | |
131 | ||
132 | for (j = 0; attribute_tables[i][j].name != NULL; j++) | |
133 | { | |
134 | /* The name must not begin and end with __. */ | |
135 | const char *name = attribute_tables[i][j].name; | |
136 | int len = strlen (name); | |
a0c938f0 | 137 | |
64db345d | 138 | gcc_assert (!(name[0] == '_' && name[1] == '_' |
139 | && name[len - 1] == '_' && name[len - 2] == '_')); | |
a0c938f0 | 140 | |
e3f6ce11 | 141 | /* The minimum and maximum lengths must be consistent. */ |
64db345d | 142 | gcc_assert (attribute_tables[i][j].min_length >= 0); |
a0c938f0 | 143 | |
64db345d | 144 | gcc_assert (attribute_tables[i][j].max_length == -1 |
145 | || (attribute_tables[i][j].max_length | |
146 | >= attribute_tables[i][j].min_length)); | |
a0c938f0 | 147 | |
e3f6ce11 | 148 | /* An attribute cannot require both a DECL and a TYPE. */ |
64db345d | 149 | gcc_assert (!attribute_tables[i][j].decl_required |
150 | || !attribute_tables[i][j].type_required); | |
a0c938f0 | 151 | |
e3f6ce11 | 152 | /* If an attribute requires a function type, in particular |
153 | it requires a type. */ | |
64db345d | 154 | gcc_assert (!attribute_tables[i][j].function_type_required |
155 | || attribute_tables[i][j].type_required); | |
e3f6ce11 | 156 | } |
157 | } | |
158 | ||
159 | /* Check that each name occurs just once in each table. */ | |
3585dac7 | 160 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) |
e3f6ce11 | 161 | { |
162 | int j, k; | |
163 | for (j = 0; attribute_tables[i][j].name != NULL; j++) | |
164 | for (k = j + 1; attribute_tables[i][k].name != NULL; k++) | |
64db345d | 165 | gcc_assert (strcmp (attribute_tables[i][j].name, |
166 | attribute_tables[i][k].name)); | |
e3f6ce11 | 167 | } |
168 | /* Check that no name occurs in more than one table. */ | |
3585dac7 | 169 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) |
e3f6ce11 | 170 | { |
3585dac7 | 171 | size_t j, k, l; |
e3f6ce11 | 172 | |
3585dac7 | 173 | for (j = i + 1; j < ARRAY_SIZE (attribute_tables); j++) |
e3f6ce11 | 174 | for (k = 0; attribute_tables[i][k].name != NULL; k++) |
175 | for (l = 0; attribute_tables[j][l].name != NULL; l++) | |
64db345d | 176 | gcc_assert (strcmp (attribute_tables[i][k].name, |
177 | attribute_tables[j][l].name)); | |
e3f6ce11 | 178 | } |
179 | #endif | |
180 | ||
5b634bfa | 181 | attribute_hash = htab_create (200, hash_attr, eq_attr, NULL); |
182 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) | |
183 | for (k = 0; attribute_tables[i][k].name != NULL; k++) | |
184 | { | |
e3fced1a | 185 | register_attribute (&attribute_tables[i][k]); |
186 | } | |
187 | invoke_plugin_callbacks (PLUGIN_ATTRIBUTES, NULL); | |
188 | attributes_initialized = true; | |
189 | } | |
190 | ||
191 | /* Insert a single ATTR into the attribute table. */ | |
192 | ||
193 | void | |
48e1416a | 194 | register_attribute (const struct attribute_spec *attr) |
e3fced1a | 195 | { |
4fb84273 | 196 | struct substring str; |
402ba866 | 197 | void **slot; |
4fb84273 | 198 | |
199 | str.str = attr->name; | |
200 | str.length = strlen (str.str); | |
402ba866 | 201 | slot = htab_find_slot_with_hash (attribute_hash, &str, |
202 | substring_hash (str.str, str.length), | |
203 | INSERT); | |
4fb84273 | 204 | gcc_assert (!*slot); |
402ba866 | 205 | *slot = (void *) CONST_CAST (struct attribute_spec *, attr); |
e3f6ce11 | 206 | } |
2fdd6488 | 207 | |
208 | /* Return the spec for the attribute named NAME. */ | |
209 | ||
210 | const struct attribute_spec * | |
211 | lookup_attribute_spec (tree name) | |
212 | { | |
213 | struct substring attr; | |
214 | ||
215 | attr.str = IDENTIFIER_POINTER (name); | |
216 | attr.length = IDENTIFIER_LENGTH (name); | |
217 | extract_attribute_substring (&attr); | |
364c0c59 | 218 | return (const struct attribute_spec *) |
219 | htab_find_with_hash (attribute_hash, &attr, | |
220 | substring_hash (attr.str, attr.length)); | |
2fdd6488 | 221 | } |
e3f6ce11 | 222 | \f |
223 | /* Process the attributes listed in ATTRIBUTES and install them in *NODE, | |
224 | which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL, | |
225 | it should be modified in place; if a TYPE, a copy should be created | |
226 | unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS. FLAGS gives further | |
227 | information, in the form of a bitwise OR of flags in enum attribute_flags | |
228 | from tree.h. Depending on these flags, some attributes may be | |
229 | returned to be applied at a later stage (for example, to apply | |
101cc430 | 230 | a decl attribute to the declaration rather than to its type). */ |
e3f6ce11 | 231 | |
232 | tree | |
aecda0d6 | 233 | decl_attributes (tree *node, tree attributes, int flags) |
e3f6ce11 | 234 | { |
235 | tree a; | |
236 | tree returned_attrs = NULL_TREE; | |
237 | ||
1ccba7b7 | 238 | if (TREE_TYPE (*node) == error_mark_node) |
239 | return NULL_TREE; | |
240 | ||
e3f6ce11 | 241 | if (!attributes_initialized) |
242 | init_attributes (); | |
243 | ||
46f8e3b0 | 244 | /* If this is a function and the user used #pragma GCC optimize, add the |
245 | options to the attribute((optimize(...))) list. */ | |
246 | if (TREE_CODE (*node) == FUNCTION_DECL && current_optimize_pragma) | |
247 | { | |
248 | tree cur_attr = lookup_attribute ("optimize", attributes); | |
249 | tree opts = copy_list (current_optimize_pragma); | |
250 | ||
251 | if (! cur_attr) | |
252 | attributes | |
253 | = tree_cons (get_identifier ("optimize"), opts, attributes); | |
254 | else | |
255 | TREE_VALUE (cur_attr) = chainon (opts, TREE_VALUE (cur_attr)); | |
256 | } | |
257 | ||
258 | if (TREE_CODE (*node) == FUNCTION_DECL | |
259 | && optimization_current_node != optimization_default_node | |
260 | && !DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)) | |
261 | DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node) = optimization_current_node; | |
262 | ||
24470055 | 263 | /* If this is a function and the user used #pragma GCC target, add the |
264 | options to the attribute((target(...))) list. */ | |
46f8e3b0 | 265 | if (TREE_CODE (*node) == FUNCTION_DECL |
24470055 | 266 | && current_target_pragma |
46f8e3b0 | 267 | && targetm.target_option.valid_attribute_p (*node, NULL_TREE, |
24470055 | 268 | current_target_pragma, 0)) |
46f8e3b0 | 269 | { |
24470055 | 270 | tree cur_attr = lookup_attribute ("target", attributes); |
271 | tree opts = copy_list (current_target_pragma); | |
46f8e3b0 | 272 | |
273 | if (! cur_attr) | |
24470055 | 274 | attributes = tree_cons (get_identifier ("target"), opts, attributes); |
46f8e3b0 | 275 | else |
276 | TREE_VALUE (cur_attr) = chainon (opts, TREE_VALUE (cur_attr)); | |
277 | } | |
278 | ||
883b2e73 | 279 | targetm.insert_attributes (*node, &attributes); |
e3f6ce11 | 280 | |
281 | for (a = attributes; a; a = TREE_CHAIN (a)) | |
282 | { | |
283 | tree name = TREE_PURPOSE (a); | |
284 | tree args = TREE_VALUE (a); | |
285 | tree *anode = node; | |
2fdd6488 | 286 | const struct attribute_spec *spec = lookup_attribute_spec (name); |
e3f6ce11 | 287 | bool no_add_attrs = 0; |
ce6dcb60 | 288 | int fn_ptr_quals = 0; |
79bdd5ff | 289 | tree fn_ptr_tmp = NULL_TREE; |
e3f6ce11 | 290 | |
291 | if (spec == NULL) | |
292 | { | |
abd3e6b5 | 293 | warning (OPT_Wattributes, "%qE attribute directive ignored", |
294 | name); | |
e3f6ce11 | 295 | continue; |
296 | } | |
297 | else if (list_length (args) < spec->min_length | |
298 | || (spec->max_length >= 0 | |
299 | && list_length (args) > spec->max_length)) | |
300 | { | |
abd3e6b5 | 301 | error ("wrong number of arguments specified for %qE attribute", |
302 | name); | |
e3f6ce11 | 303 | continue; |
304 | } | |
5b634bfa | 305 | gcc_assert (is_attribute_p (spec->name, name)); |
e3f6ce11 | 306 | |
307 | if (spec->decl_required && !DECL_P (*anode)) | |
308 | { | |
309 | if (flags & ((int) ATTR_FLAG_DECL_NEXT | |
310 | | (int) ATTR_FLAG_FUNCTION_NEXT | |
311 | | (int) ATTR_FLAG_ARRAY_NEXT)) | |
312 | { | |
313 | /* Pass on this attribute to be tried again. */ | |
314 | returned_attrs = tree_cons (name, args, returned_attrs); | |
315 | continue; | |
316 | } | |
317 | else | |
318 | { | |
abd3e6b5 | 319 | warning (OPT_Wattributes, "%qE attribute does not apply to types", |
320 | name); | |
e3f6ce11 | 321 | continue; |
322 | } | |
323 | } | |
324 | ||
aa9c60c1 | 325 | /* If we require a type, but were passed a decl, set up to make a |
326 | new type and update the one in the decl. ATTR_FLAG_TYPE_IN_PLACE | |
327 | would have applied if we'd been passed a type, but we cannot modify | |
328 | the decl's type in place here. */ | |
e3f6ce11 | 329 | if (spec->type_required && DECL_P (*anode)) |
aa9c60c1 | 330 | { |
331 | anode = &TREE_TYPE (*anode); | |
3ef0a05e | 332 | /* Allow ATTR_FLAG_TYPE_IN_PLACE for the type's naming decl. */ |
333 | if (!(TREE_CODE (*anode) == TYPE_DECL | |
334 | && *anode == TYPE_NAME (TYPE_MAIN_VARIANT | |
335 | (TREE_TYPE (*anode))))) | |
336 | flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE; | |
aa9c60c1 | 337 | } |
e3f6ce11 | 338 | |
339 | if (spec->function_type_required && TREE_CODE (*anode) != FUNCTION_TYPE | |
340 | && TREE_CODE (*anode) != METHOD_TYPE) | |
341 | { | |
342 | if (TREE_CODE (*anode) == POINTER_TYPE | |
343 | && (TREE_CODE (TREE_TYPE (*anode)) == FUNCTION_TYPE | |
344 | || TREE_CODE (TREE_TYPE (*anode)) == METHOD_TYPE)) | |
345 | { | |
79bdd5ff | 346 | /* OK, this is a bit convoluted. We can't just make a copy |
347 | of the pointer type and modify its TREE_TYPE, because if | |
348 | we change the attributes of the target type the pointer | |
349 | type needs to have a different TYPE_MAIN_VARIANT. So we | |
350 | pull out the target type now, frob it as appropriate, and | |
351 | rebuild the pointer type later. | |
352 | ||
a0c938f0 | 353 | This would all be simpler if attributes were part of the |
354 | declarator, grumble grumble. */ | |
79bdd5ff | 355 | fn_ptr_tmp = TREE_TYPE (*anode); |
ce6dcb60 | 356 | fn_ptr_quals = TYPE_QUALS (*anode); |
79bdd5ff | 357 | anode = &fn_ptr_tmp; |
358 | flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE; | |
e3f6ce11 | 359 | } |
360 | else if (flags & (int) ATTR_FLAG_FUNCTION_NEXT) | |
361 | { | |
362 | /* Pass on this attribute to be tried again. */ | |
363 | returned_attrs = tree_cons (name, args, returned_attrs); | |
364 | continue; | |
365 | } | |
366 | ||
367 | if (TREE_CODE (*anode) != FUNCTION_TYPE | |
368 | && TREE_CODE (*anode) != METHOD_TYPE) | |
369 | { | |
9b2d6d13 | 370 | warning (OPT_Wattributes, |
abd3e6b5 | 371 | "%qE attribute only applies to function types", |
372 | name); | |
e3f6ce11 | 373 | continue; |
374 | } | |
375 | } | |
376 | ||
4a2849cb | 377 | if (TYPE_P (*anode) |
378 | && (flags & (int) ATTR_FLAG_TYPE_IN_PLACE) | |
379 | && TYPE_SIZE (*anode) != NULL_TREE) | |
380 | { | |
381 | warning (OPT_Wattributes, "type attributes ignored after type is already defined"); | |
382 | continue; | |
383 | } | |
384 | ||
e3f6ce11 | 385 | if (spec->handler != NULL) |
386 | returned_attrs = chainon ((*spec->handler) (anode, name, args, | |
387 | flags, &no_add_attrs), | |
388 | returned_attrs); | |
ae4718db | 389 | |
390 | /* Layout the decl in case anything changed. */ | |
391 | if (spec->type_required && DECL_P (*node) | |
e56de52f | 392 | && (TREE_CODE (*node) == VAR_DECL |
393 | || TREE_CODE (*node) == PARM_DECL | |
394 | || TREE_CODE (*node) == RESULT_DECL)) | |
1c0a6d1e | 395 | relayout_decl (*node); |
ae4718db | 396 | |
e3f6ce11 | 397 | if (!no_add_attrs) |
398 | { | |
399 | tree old_attrs; | |
400 | tree a; | |
401 | ||
402 | if (DECL_P (*anode)) | |
403 | old_attrs = DECL_ATTRIBUTES (*anode); | |
404 | else | |
405 | old_attrs = TYPE_ATTRIBUTES (*anode); | |
406 | ||
407 | for (a = lookup_attribute (spec->name, old_attrs); | |
408 | a != NULL_TREE; | |
409 | a = lookup_attribute (spec->name, TREE_CHAIN (a))) | |
410 | { | |
411 | if (simple_cst_equal (TREE_VALUE (a), args) == 1) | |
412 | break; | |
413 | } | |
414 | ||
415 | if (a == NULL_TREE) | |
416 | { | |
417 | /* This attribute isn't already in the list. */ | |
418 | if (DECL_P (*anode)) | |
419 | DECL_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs); | |
420 | else if (flags & (int) ATTR_FLAG_TYPE_IN_PLACE) | |
316e17ae | 421 | { |
422 | TYPE_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs); | |
423 | /* If this is the main variant, also push the attributes | |
424 | out to the other variants. */ | |
425 | if (*anode == TYPE_MAIN_VARIANT (*anode)) | |
426 | { | |
427 | tree variant; | |
428 | for (variant = *anode; variant; | |
429 | variant = TYPE_NEXT_VARIANT (variant)) | |
430 | { | |
431 | if (TYPE_ATTRIBUTES (variant) == old_attrs) | |
432 | TYPE_ATTRIBUTES (variant) | |
433 | = TYPE_ATTRIBUTES (*anode); | |
434 | else if (!lookup_attribute | |
435 | (spec->name, TYPE_ATTRIBUTES (variant))) | |
436 | TYPE_ATTRIBUTES (variant) = tree_cons | |
437 | (name, args, TYPE_ATTRIBUTES (variant)); | |
438 | } | |
439 | } | |
440 | } | |
e3f6ce11 | 441 | else |
442 | *anode = build_type_attribute_variant (*anode, | |
443 | tree_cons (name, args, | |
444 | old_attrs)); | |
445 | } | |
446 | } | |
79bdd5ff | 447 | |
448 | if (fn_ptr_tmp) | |
449 | { | |
450 | /* Rebuild the function pointer type and put it in the | |
451 | appropriate place. */ | |
452 | fn_ptr_tmp = build_pointer_type (fn_ptr_tmp); | |
ce6dcb60 | 453 | if (fn_ptr_quals) |
454 | fn_ptr_tmp = build_qualified_type (fn_ptr_tmp, fn_ptr_quals); | |
79bdd5ff | 455 | if (DECL_P (*node)) |
456 | TREE_TYPE (*node) = fn_ptr_tmp; | |
79bdd5ff | 457 | else |
64db345d | 458 | { |
459 | gcc_assert (TREE_CODE (*node) == POINTER_TYPE); | |
460 | *node = fn_ptr_tmp; | |
461 | } | |
79bdd5ff | 462 | } |
e3f6ce11 | 463 | } |
464 | ||
465 | return returned_attrs; | |
466 | } |