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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, |
8c4c00c1 | 3 | 2002, 2003, 2004, 2005, 2007 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" |
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 | { | |
185 | struct substring str; | |
b7bf20db | 186 | const void **slot; |
5b634bfa | 187 | |
188 | str.str = attribute_tables[i][k].name; | |
189 | str.length = strlen (attribute_tables[i][k].name); | |
b7bf20db | 190 | slot = (const void **)htab_find_slot_with_hash (attribute_hash, &str, |
5b634bfa | 191 | substring_hash (str.str, str.length), |
192 | INSERT); | |
193 | gcc_assert (!*slot); | |
b7bf20db | 194 | *slot = &attribute_tables[i][k]; |
5b634bfa | 195 | } |
e3f6ce11 | 196 | attributes_initialized = true; |
197 | } | |
2fdd6488 | 198 | |
199 | /* Return the spec for the attribute named NAME. */ | |
200 | ||
201 | const struct attribute_spec * | |
202 | lookup_attribute_spec (tree name) | |
203 | { | |
204 | struct substring attr; | |
205 | ||
206 | attr.str = IDENTIFIER_POINTER (name); | |
207 | attr.length = IDENTIFIER_LENGTH (name); | |
208 | extract_attribute_substring (&attr); | |
209 | return htab_find_with_hash (attribute_hash, &attr, | |
210 | substring_hash (attr.str, attr.length)); | |
211 | } | |
e3f6ce11 | 212 | \f |
213 | /* Process the attributes listed in ATTRIBUTES and install them in *NODE, | |
214 | which is either a DECL (including a TYPE_DECL) or a TYPE. If a DECL, | |
215 | it should be modified in place; if a TYPE, a copy should be created | |
216 | unless ATTR_FLAG_TYPE_IN_PLACE is set in FLAGS. FLAGS gives further | |
217 | information, in the form of a bitwise OR of flags in enum attribute_flags | |
218 | from tree.h. Depending on these flags, some attributes may be | |
219 | returned to be applied at a later stage (for example, to apply | |
101cc430 | 220 | a decl attribute to the declaration rather than to its type). */ |
e3f6ce11 | 221 | |
222 | tree | |
aecda0d6 | 223 | decl_attributes (tree *node, tree attributes, int flags) |
e3f6ce11 | 224 | { |
225 | tree a; | |
226 | tree returned_attrs = NULL_TREE; | |
227 | ||
1ccba7b7 | 228 | if (TREE_TYPE (*node) == error_mark_node) |
229 | return NULL_TREE; | |
230 | ||
e3f6ce11 | 231 | if (!attributes_initialized) |
232 | init_attributes (); | |
233 | ||
883b2e73 | 234 | targetm.insert_attributes (*node, &attributes); |
e3f6ce11 | 235 | |
236 | for (a = attributes; a; a = TREE_CHAIN (a)) | |
237 | { | |
238 | tree name = TREE_PURPOSE (a); | |
239 | tree args = TREE_VALUE (a); | |
240 | tree *anode = node; | |
2fdd6488 | 241 | const struct attribute_spec *spec = lookup_attribute_spec (name); |
e3f6ce11 | 242 | bool no_add_attrs = 0; |
79bdd5ff | 243 | tree fn_ptr_tmp = NULL_TREE; |
e3f6ce11 | 244 | |
245 | if (spec == NULL) | |
246 | { | |
9b2d6d13 | 247 | warning (OPT_Wattributes, "%qs attribute directive ignored", |
e3f6ce11 | 248 | IDENTIFIER_POINTER (name)); |
249 | continue; | |
250 | } | |
251 | else if (list_length (args) < spec->min_length | |
252 | || (spec->max_length >= 0 | |
253 | && list_length (args) > spec->max_length)) | |
254 | { | |
eb586f2c | 255 | error ("wrong number of arguments specified for %qs attribute", |
e3f6ce11 | 256 | IDENTIFIER_POINTER (name)); |
257 | continue; | |
258 | } | |
5b634bfa | 259 | gcc_assert (is_attribute_p (spec->name, name)); |
e3f6ce11 | 260 | |
261 | if (spec->decl_required && !DECL_P (*anode)) | |
262 | { | |
263 | if (flags & ((int) ATTR_FLAG_DECL_NEXT | |
264 | | (int) ATTR_FLAG_FUNCTION_NEXT | |
265 | | (int) ATTR_FLAG_ARRAY_NEXT)) | |
266 | { | |
267 | /* Pass on this attribute to be tried again. */ | |
268 | returned_attrs = tree_cons (name, args, returned_attrs); | |
269 | continue; | |
270 | } | |
271 | else | |
272 | { | |
9b2d6d13 | 273 | warning (OPT_Wattributes, "%qs attribute does not apply to types", |
e3f6ce11 | 274 | IDENTIFIER_POINTER (name)); |
275 | continue; | |
276 | } | |
277 | } | |
278 | ||
aa9c60c1 | 279 | /* If we require a type, but were passed a decl, set up to make a |
280 | new type and update the one in the decl. ATTR_FLAG_TYPE_IN_PLACE | |
281 | would have applied if we'd been passed a type, but we cannot modify | |
282 | the decl's type in place here. */ | |
e3f6ce11 | 283 | if (spec->type_required && DECL_P (*anode)) |
aa9c60c1 | 284 | { |
285 | anode = &TREE_TYPE (*anode); | |
3ef0a05e | 286 | /* Allow ATTR_FLAG_TYPE_IN_PLACE for the type's naming decl. */ |
287 | if (!(TREE_CODE (*anode) == TYPE_DECL | |
288 | && *anode == TYPE_NAME (TYPE_MAIN_VARIANT | |
289 | (TREE_TYPE (*anode))))) | |
290 | flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE; | |
aa9c60c1 | 291 | } |
e3f6ce11 | 292 | |
293 | if (spec->function_type_required && TREE_CODE (*anode) != FUNCTION_TYPE | |
294 | && TREE_CODE (*anode) != METHOD_TYPE) | |
295 | { | |
296 | if (TREE_CODE (*anode) == POINTER_TYPE | |
297 | && (TREE_CODE (TREE_TYPE (*anode)) == FUNCTION_TYPE | |
298 | || TREE_CODE (TREE_TYPE (*anode)) == METHOD_TYPE)) | |
299 | { | |
79bdd5ff | 300 | /* OK, this is a bit convoluted. We can't just make a copy |
301 | of the pointer type and modify its TREE_TYPE, because if | |
302 | we change the attributes of the target type the pointer | |
303 | type needs to have a different TYPE_MAIN_VARIANT. So we | |
304 | pull out the target type now, frob it as appropriate, and | |
305 | rebuild the pointer type later. | |
306 | ||
a0c938f0 | 307 | This would all be simpler if attributes were part of the |
308 | declarator, grumble grumble. */ | |
79bdd5ff | 309 | fn_ptr_tmp = TREE_TYPE (*anode); |
310 | anode = &fn_ptr_tmp; | |
311 | flags &= ~(int) ATTR_FLAG_TYPE_IN_PLACE; | |
e3f6ce11 | 312 | } |
313 | else if (flags & (int) ATTR_FLAG_FUNCTION_NEXT) | |
314 | { | |
315 | /* Pass on this attribute to be tried again. */ | |
316 | returned_attrs = tree_cons (name, args, returned_attrs); | |
317 | continue; | |
318 | } | |
319 | ||
320 | if (TREE_CODE (*anode) != FUNCTION_TYPE | |
321 | && TREE_CODE (*anode) != METHOD_TYPE) | |
322 | { | |
9b2d6d13 | 323 | warning (OPT_Wattributes, |
324 | "%qs attribute only applies to function types", | |
e3f6ce11 | 325 | IDENTIFIER_POINTER (name)); |
326 | continue; | |
327 | } | |
328 | } | |
329 | ||
4a2849cb | 330 | if (TYPE_P (*anode) |
331 | && (flags & (int) ATTR_FLAG_TYPE_IN_PLACE) | |
332 | && TYPE_SIZE (*anode) != NULL_TREE) | |
333 | { | |
334 | warning (OPT_Wattributes, "type attributes ignored after type is already defined"); | |
335 | continue; | |
336 | } | |
337 | ||
e3f6ce11 | 338 | if (spec->handler != NULL) |
339 | returned_attrs = chainon ((*spec->handler) (anode, name, args, | |
340 | flags, &no_add_attrs), | |
341 | returned_attrs); | |
ae4718db | 342 | |
343 | /* Layout the decl in case anything changed. */ | |
344 | if (spec->type_required && DECL_P (*node) | |
e56de52f | 345 | && (TREE_CODE (*node) == VAR_DECL |
346 | || TREE_CODE (*node) == PARM_DECL | |
347 | || TREE_CODE (*node) == RESULT_DECL)) | |
1c0a6d1e | 348 | relayout_decl (*node); |
ae4718db | 349 | |
e3f6ce11 | 350 | if (!no_add_attrs) |
351 | { | |
352 | tree old_attrs; | |
353 | tree a; | |
354 | ||
355 | if (DECL_P (*anode)) | |
356 | old_attrs = DECL_ATTRIBUTES (*anode); | |
357 | else | |
358 | old_attrs = TYPE_ATTRIBUTES (*anode); | |
359 | ||
360 | for (a = lookup_attribute (spec->name, old_attrs); | |
361 | a != NULL_TREE; | |
362 | a = lookup_attribute (spec->name, TREE_CHAIN (a))) | |
363 | { | |
364 | if (simple_cst_equal (TREE_VALUE (a), args) == 1) | |
365 | break; | |
366 | } | |
367 | ||
368 | if (a == NULL_TREE) | |
369 | { | |
370 | /* This attribute isn't already in the list. */ | |
371 | if (DECL_P (*anode)) | |
372 | DECL_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs); | |
373 | else if (flags & (int) ATTR_FLAG_TYPE_IN_PLACE) | |
316e17ae | 374 | { |
375 | TYPE_ATTRIBUTES (*anode) = tree_cons (name, args, old_attrs); | |
376 | /* If this is the main variant, also push the attributes | |
377 | out to the other variants. */ | |
378 | if (*anode == TYPE_MAIN_VARIANT (*anode)) | |
379 | { | |
380 | tree variant; | |
381 | for (variant = *anode; variant; | |
382 | variant = TYPE_NEXT_VARIANT (variant)) | |
383 | { | |
384 | if (TYPE_ATTRIBUTES (variant) == old_attrs) | |
385 | TYPE_ATTRIBUTES (variant) | |
386 | = TYPE_ATTRIBUTES (*anode); | |
387 | else if (!lookup_attribute | |
388 | (spec->name, TYPE_ATTRIBUTES (variant))) | |
389 | TYPE_ATTRIBUTES (variant) = tree_cons | |
390 | (name, args, TYPE_ATTRIBUTES (variant)); | |
391 | } | |
392 | } | |
393 | } | |
e3f6ce11 | 394 | else |
395 | *anode = build_type_attribute_variant (*anode, | |
396 | tree_cons (name, args, | |
397 | old_attrs)); | |
398 | } | |
399 | } | |
79bdd5ff | 400 | |
401 | if (fn_ptr_tmp) | |
402 | { | |
403 | /* Rebuild the function pointer type and put it in the | |
404 | appropriate place. */ | |
405 | fn_ptr_tmp = build_pointer_type (fn_ptr_tmp); | |
406 | if (DECL_P (*node)) | |
407 | TREE_TYPE (*node) = fn_ptr_tmp; | |
79bdd5ff | 408 | else |
64db345d | 409 | { |
410 | gcc_assert (TREE_CODE (*node) == POINTER_TYPE); | |
411 | *node = fn_ptr_tmp; | |
412 | } | |
79bdd5ff | 413 | } |
e3f6ce11 | 414 | } |
415 | ||
416 | return returned_attrs; | |
417 | } |