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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, |
cfaf579d | 3 | 2002, 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc. |
e3f6ce11 | 4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
e3f6ce11 | 10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
e3f6ce11 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
805e22b2 | 23 | #include "coretypes.h" |
24 | #include "tm.h" | |
e3f6ce11 | 25 | #include "tree.h" |
26 | #include "flags.h" | |
27 | #include "toplev.h" | |
28 | #include "output.h" | |
29 | #include "rtl.h" | |
30 | #include "ggc.h" | |
e3f6ce11 | 31 | #include "tm_p.h" |
e3f6ce11 | 32 | #include "cpplib.h" |
33 | #include "target.h" | |
26ca6c20 | 34 | #include "langhooks.h" |
5b634bfa | 35 | #include "hashtab.h" |
e3fced1a | 36 | #include "plugin.h" |
e3f6ce11 | 37 | |
aecda0d6 | 38 | static void init_attributes (void); |
e3f6ce11 | 39 | |
f8e93a2e | 40 | /* Table of the tables of attributes (common, language, format, machine) |
e3f6ce11 | 41 | searched. */ |
42 | static const struct attribute_spec *attribute_tables[4]; | |
43 | ||
5b634bfa | 44 | /* Hashtable mapping names (represented as substrings) to attribute specs. */ |
45 | static htab_t attribute_hash; | |
46 | ||
47 | /* Substring representation. */ | |
48 | ||
49 | struct substring | |
50 | { | |
51 | const char *str; | |
52 | int length; | |
53 | }; | |
54 | ||
e3f6ce11 | 55 | static bool attributes_initialized = false; |
56 | ||
e3f6ce11 | 57 | /* Default empty table of attributes. */ |
5b634bfa | 58 | |
e3f6ce11 | 59 | static const struct attribute_spec empty_attribute_table[] = |
60 | { | |
61 | { NULL, 0, 0, false, false, false, NULL } | |
62 | }; | |
63 | ||
5b634bfa | 64 | /* Return base name of the attribute. Ie '__attr__' is turned into 'attr'. |
65 | To avoid need for copying, we simply return length of the string. */ | |
66 | ||
67 | static void | |
68 | extract_attribute_substring (struct substring *str) | |
69 | { | |
70 | if (str->length > 4 && str->str[0] == '_' && str->str[1] == '_' | |
71 | && str->str[str->length - 1] == '_' && str->str[str->length - 2] == '_') | |
72 | { | |
73 | str->length -= 4; | |
74 | str->str += 2; | |
75 | } | |
76 | } | |
77 | ||
78 | /* Simple hash function to avoid need to scan whole string. */ | |
79 | ||
80 | static inline hashval_t | |
81 | substring_hash (const char *str, int l) | |
82 | { | |
83 | return str[0] + str[l - 1] * 256 + l * 65536; | |
84 | } | |
85 | ||
86 | /* Used for attribute_hash. */ | |
87 | ||
88 | static hashval_t | |
89 | hash_attr (const void *p) | |
90 | { | |
b7bf20db | 91 | const struct attribute_spec *const spec = (const struct attribute_spec *) p; |
92 | const int l = strlen (spec->name); | |
5b634bfa | 93 | |
94 | return substring_hash (spec->name, l); | |
95 | } | |
96 | ||
97 | /* Used for attribute_hash. */ | |
98 | ||
99 | static int | |
100 | eq_attr (const void *p, const void *q) | |
101 | { | |
b7bf20db | 102 | const struct attribute_spec *const spec = (const struct attribute_spec *) p; |
103 | const struct substring *const str = (const struct substring *) q; | |
5b634bfa | 104 | |
105 | return (!strncmp (spec->name, str->str, str->length) && !spec->name[str->length]); | |
106 | } | |
107 | ||
e3f6ce11 | 108 | /* Initialize attribute tables, and make some sanity checks |
109 | if --enable-checking. */ | |
110 | ||
111 | static void | |
aecda0d6 | 112 | init_attributes (void) |
e3f6ce11 | 113 | { |
3585dac7 | 114 | size_t i; |
5b634bfa | 115 | int k; |
e3f6ce11 | 116 | |
f8e93a2e | 117 | attribute_tables[0] = lang_hooks.common_attribute_table; |
118 | attribute_tables[1] = lang_hooks.attribute_table; | |
119 | attribute_tables[2] = lang_hooks.format_attribute_table; | |
e3f6ce11 | 120 | attribute_tables[3] = targetm.attribute_table; |
121 | ||
f8e93a2e | 122 | /* Translate NULL pointers to pointers to the empty table. */ |
123 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) | |
124 | if (attribute_tables[i] == NULL) | |
125 | attribute_tables[i] = empty_attribute_table; | |
126 | ||
e3f6ce11 | 127 | #ifdef ENABLE_CHECKING |
128 | /* Make some sanity checks on the attribute tables. */ | |
3585dac7 | 129 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) |
e3f6ce11 | 130 | { |
131 | int j; | |
132 | ||
133 | for (j = 0; attribute_tables[i][j].name != NULL; j++) | |
134 | { | |
135 | /* The name must not begin and end with __. */ | |
136 | const char *name = attribute_tables[i][j].name; | |
137 | int len = strlen (name); | |
a0c938f0 | 138 | |
64db345d | 139 | gcc_assert (!(name[0] == '_' && name[1] == '_' |
140 | && name[len - 1] == '_' && name[len - 2] == '_')); | |
a0c938f0 | 141 | |
e3f6ce11 | 142 | /* The minimum and maximum lengths must be consistent. */ |
64db345d | 143 | gcc_assert (attribute_tables[i][j].min_length >= 0); |
a0c938f0 | 144 | |
64db345d | 145 | gcc_assert (attribute_tables[i][j].max_length == -1 |
146 | || (attribute_tables[i][j].max_length | |
147 | >= attribute_tables[i][j].min_length)); | |
a0c938f0 | 148 | |
e3f6ce11 | 149 | /* An attribute cannot require both a DECL and a TYPE. */ |
64db345d | 150 | gcc_assert (!attribute_tables[i][j].decl_required |
151 | || !attribute_tables[i][j].type_required); | |
a0c938f0 | 152 | |
e3f6ce11 | 153 | /* If an attribute requires a function type, in particular |
154 | it requires a type. */ | |
64db345d | 155 | gcc_assert (!attribute_tables[i][j].function_type_required |
156 | || attribute_tables[i][j].type_required); | |
e3f6ce11 | 157 | } |
158 | } | |
159 | ||
160 | /* Check that each name occurs just once in each table. */ | |
3585dac7 | 161 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) |
e3f6ce11 | 162 | { |
163 | int j, k; | |
164 | for (j = 0; attribute_tables[i][j].name != NULL; j++) | |
165 | for (k = j + 1; attribute_tables[i][k].name != NULL; k++) | |
64db345d | 166 | gcc_assert (strcmp (attribute_tables[i][j].name, |
167 | attribute_tables[i][k].name)); | |
e3f6ce11 | 168 | } |
169 | /* Check that no name occurs in more than one table. */ | |
3585dac7 | 170 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) |
e3f6ce11 | 171 | { |
3585dac7 | 172 | size_t j, k, l; |
e3f6ce11 | 173 | |
3585dac7 | 174 | for (j = i + 1; j < ARRAY_SIZE (attribute_tables); j++) |
e3f6ce11 | 175 | for (k = 0; attribute_tables[i][k].name != NULL; k++) |
176 | for (l = 0; attribute_tables[j][l].name != NULL; l++) | |
64db345d | 177 | gcc_assert (strcmp (attribute_tables[i][k].name, |
178 | attribute_tables[j][l].name)); | |
e3f6ce11 | 179 | } |
180 | #endif | |
181 | ||
5b634bfa | 182 | attribute_hash = htab_create (200, hash_attr, eq_attr, NULL); |
183 | for (i = 0; i < ARRAY_SIZE (attribute_tables); i++) | |
184 | for (k = 0; attribute_tables[i][k].name != NULL; k++) | |
185 | { | |
e3fced1a | 186 | register_attribute (&attribute_tables[i][k]); |
187 | } | |
188 | invoke_plugin_callbacks (PLUGIN_ATTRIBUTES, NULL); | |
189 | attributes_initialized = true; | |
190 | } | |
191 | ||
192 | /* Insert a single ATTR into the attribute table. */ | |
193 | ||
194 | void | |
195 | register_attribute (const struct attribute_spec *attr) | |
196 | { | |
4fb84273 | 197 | struct substring str; |
198 | const void **slot; | |
199 | ||
200 | str.str = attr->name; | |
201 | str.length = strlen (str.str); | |
202 | slot = (const void **)htab_find_slot_with_hash (attribute_hash, &str, | |
203 | substring_hash (str.str, str.length), | |
204 | INSERT); | |
205 | gcc_assert (!*slot); | |
206 | *slot = attr; | |
e3f6ce11 | 207 | } |
2fdd6488 | 208 | |
209 | /* Return the spec for the attribute named NAME. */ | |
210 | ||
211 | const struct attribute_spec * | |
212 | lookup_attribute_spec (tree name) | |
213 | { | |
214 | struct substring attr; | |
215 | ||
216 | attr.str = IDENTIFIER_POINTER (name); | |
217 | attr.length = IDENTIFIER_LENGTH (name); | |
218 | extract_attribute_substring (&attr); | |
364c0c59 | 219 | return (const struct attribute_spec *) |
220 | htab_find_with_hash (attribute_hash, &attr, | |
221 | substring_hash (attr.str, attr.length)); | |
2fdd6488 | 222 | } |
e3f6ce11 | 223 | \f |
224 | /* Process the attributes listed in ATTRIBUTES and install them in *NODE, | |
225 | which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL, | |
226 | it should be modified in place; if a TYPE, a copy should be created | |
227 | unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS. FLAGS gives further | |
228 | information, in the form of a bitwise OR of flags in enum attribute_flags | |
229 | from tree.h. Depending on these flags, some attributes may be | |
230 | returned to be applied at a later stage (for example, to apply | |
101cc430 | 231 | a decl attribute to the declaration rather than to its type). */ |
e3f6ce11 | 232 | |
233 | tree | |
aecda0d6 | 234 | decl_attributes (tree *node, tree attributes, int flags) |
e3f6ce11 | 235 | { |
236 | tree a; | |
237 | tree returned_attrs = NULL_TREE; | |
238 | ||
1ccba7b7 | 239 | if (TREE_TYPE (*node) == error_mark_node) |
240 | return NULL_TREE; | |
241 | ||
e3f6ce11 | 242 | if (!attributes_initialized) |
243 | init_attributes (); | |
244 | ||
46f8e3b0 | 245 | /* If this is a function and the user used #pragma GCC optimize, add the |
246 | options to the attribute((optimize(...))) list. */ | |
247 | if (TREE_CODE (*node) == FUNCTION_DECL && current_optimize_pragma) | |
248 | { | |
249 | tree cur_attr = lookup_attribute ("optimize", attributes); | |
250 | tree opts = copy_list (current_optimize_pragma); | |
251 | ||
252 | if (! cur_attr) | |
253 | attributes | |
254 | = tree_cons (get_identifier ("optimize"), opts, attributes); | |
255 | else | |
256 | TREE_VALUE (cur_attr) = chainon (opts, TREE_VALUE (cur_attr)); | |
257 | } | |
258 | ||
259 | if (TREE_CODE (*node) == FUNCTION_DECL | |
260 | && optimization_current_node != optimization_default_node | |
261 | && !DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)) | |
262 | DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node) = optimization_current_node; | |
263 | ||
24470055 | 264 | /* If this is a function and the user used #pragma GCC target, add the |
265 | options to the attribute((target(...))) list. */ | |
46f8e3b0 | 266 | if (TREE_CODE (*node) == FUNCTION_DECL |
24470055 | 267 | && current_target_pragma |
46f8e3b0 | 268 | && targetm.target_option.valid_attribute_p (*node, NULL_TREE, |
24470055 | 269 | current_target_pragma, 0)) |
46f8e3b0 | 270 | { |
24470055 | 271 | tree cur_attr = lookup_attribute ("target", attributes); |
272 | tree opts = copy_list (current_target_pragma); | |
46f8e3b0 | 273 | |
274 | if (! cur_attr) | |
24470055 | 275 | attributes = tree_cons (get_identifier ("target"), opts, attributes); |
46f8e3b0 | 276 | else |
277 | TREE_VALUE (cur_attr) = chainon (opts, TREE_VALUE (cur_attr)); | |
278 | } | |
279 | ||
883b2e73 | 280 | targetm.insert_attributes (*node, &attributes); |
e3f6ce11 | 281 | |
282 | for (a = attributes; a; a = TREE_CHAIN (a)) | |
283 | { | |
284 | tree name = TREE_PURPOSE (a); | |
285 | tree args = TREE_VALUE (a); | |
286 | tree *anode = node; | |
2fdd6488 | 287 | const struct attribute_spec *spec = lookup_attribute_spec (name); |
e3f6ce11 | 288 | bool no_add_attrs = 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); |
356 | anode = &fn_ptr_tmp; | |
357 | flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE; | |
e3f6ce11 | 358 | } |
359 | else if (flags & (int) ATTR_FLAG_FUNCTION_NEXT) | |
360 | { | |
361 | /* Pass on this attribute to be tried again. */ | |
362 | returned_attrs = tree_cons (name, args, returned_attrs); | |
363 | continue; | |
364 | } | |
365 | ||
366 | if (TREE_CODE (*anode) != FUNCTION_TYPE | |
367 | && TREE_CODE (*anode) != METHOD_TYPE) | |
368 | { | |
9b2d6d13 | 369 | warning (OPT_Wattributes, |
abd3e6b5 | 370 | "%qE attribute only applies to function types", |
371 | name); | |
e3f6ce11 | 372 | continue; |
373 | } | |
374 | } | |
375 | ||
4a2849cb | 376 | if (TYPE_P (*anode) |
377 | && (flags & (int) ATTR_FLAG_TYPE_IN_PLACE) | |
378 | && TYPE_SIZE (*anode) != NULL_TREE) | |
379 | { | |
380 | warning (OPT_Wattributes, "type attributes ignored after type is already defined"); | |
381 | continue; | |
382 | } | |
383 | ||
e3f6ce11 | 384 | if (spec->handler != NULL) |
385 | returned_attrs = chainon ((*spec->handler) (anode, name, args, | |
386 | flags, &no_add_attrs), | |
387 | returned_attrs); | |
ae4718db | 388 | |
389 | /* Layout the decl in case anything changed. */ | |
390 | if (spec->type_required && DECL_P (*node) | |
e56de52f | 391 | && (TREE_CODE (*node) == VAR_DECL |
392 | || TREE_CODE (*node) == PARM_DECL | |
393 | || TREE_CODE (*node) == RESULT_DECL)) | |
1c0a6d1e | 394 | relayout_decl (*node); |
ae4718db | 395 | |
e3f6ce11 | 396 | if (!no_add_attrs) |
397 | { | |
398 | tree old_attrs; | |
399 | tree a; | |
400 | ||
401 | if (DECL_P (*anode)) | |
402 | old_attrs = DECL_ATTRIBUTES (*anode); | |
403 | else | |
404 | old_attrs = TYPE_ATTRIBUTES (*anode); | |
405 | ||
406 | for (a = lookup_attribute (spec->name, old_attrs); | |
407 | a != NULL_TREE; | |
408 | a = lookup_attribute (spec->name, TREE_CHAIN (a))) | |
409 | { | |
410 | if (simple_cst_equal (TREE_VALUE (a), args) == 1) | |
411 | break; | |
412 | } | |
413 | ||
414 | if (a == NULL_TREE) | |
415 | { | |
416 | /* This attribute isn't already in the list. */ | |
417 | if (DECL_P (*anode)) | |
418 | DECL_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs); | |
419 | else if (flags & (int) ATTR_FLAG_TYPE_IN_PLACE) | |
316e17ae | 420 | { |
421 | TYPE_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs); | |
422 | /* If this is the main variant, also push the attributes | |
423 | out to the other variants. */ | |
424 | if (*anode == TYPE_MAIN_VARIANT (*anode)) | |
425 | { | |
426 | tree variant; | |
427 | for (variant = *anode; variant; | |
428 | variant = TYPE_NEXT_VARIANT (variant)) | |
429 | { | |
430 | if (TYPE_ATTRIBUTES (variant) == old_attrs) | |
431 | TYPE_ATTRIBUTES (variant) | |
432 | = TYPE_ATTRIBUTES (*anode); | |
433 | else if (!lookup_attribute | |
434 | (spec->name, TYPE_ATTRIBUTES (variant))) | |
435 | TYPE_ATTRIBUTES (variant) = tree_cons | |
436 | (name, args, TYPE_ATTRIBUTES (variant)); | |
437 | } | |
438 | } | |
439 | } | |
e3f6ce11 | 440 | else |
441 | *anode = build_type_attribute_variant (*anode, | |
442 | tree_cons (name, args, | |
443 | old_attrs)); | |
444 | } | |
445 | } | |
79bdd5ff | 446 | |
447 | if (fn_ptr_tmp) | |
448 | { | |
449 | /* Rebuild the function pointer type and put it in the | |
450 | appropriate place. */ | |
451 | fn_ptr_tmp = build_pointer_type (fn_ptr_tmp); | |
452 | if (DECL_P (*node)) | |
453 | TREE_TYPE (*node) = fn_ptr_tmp; | |
79bdd5ff | 454 | else |
64db345d | 455 | { |
456 | gcc_assert (TREE_CODE (*node) == POINTER_TYPE); | |
457 | *node = fn_ptr_tmp; | |
458 | } | |
79bdd5ff | 459 | } |
e3f6ce11 | 460 | } |
461 | ||
462 | return returned_attrs; | |
463 | } |