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comparison gcc/c-pragma.c @ 0:a06113de4d67

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author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
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children 3bfb6c00c1e0
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-1:000000000000 0:a06113de4d67
1 /* Handle #pragma, system V.4 style. Supports #pragma weak and #pragma pack.
2 Copyright (C) 1992, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008 Free Software Foundation, Inc.
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
9 Software Foundation; either version 3, or (at your option) any later
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
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "function.h"
28 #include "cpplib.h"
29 #include "c-pragma.h"
30 #include "flags.h"
31 #include "toplev.h"
32 #include "ggc.h"
33 #include "c-common.h"
34 #include "output.h"
35 #include "tm_p.h"
36 #include "vec.h"
37 #include "target.h"
38 #include "diagnostic.h"
39 #include "opts.h"
40
41 #define GCC_BAD(gmsgid) \
42 do { warning (OPT_Wpragmas, gmsgid); return; } while (0)
43 #define GCC_BAD2(gmsgid, arg) \
44 do { warning (OPT_Wpragmas, gmsgid, arg); return; } while (0)
45
46 typedef struct align_stack GTY(())
47 {
48 int alignment;
49 tree id;
50 struct align_stack * prev;
51 } align_stack;
52
53 static GTY(()) struct align_stack * alignment_stack;
54
55 #ifdef HANDLE_PRAGMA_PACK
56 static void handle_pragma_pack (cpp_reader *);
57
58 #ifdef HANDLE_PRAGMA_PACK_PUSH_POP
59 /* If we have a "global" #pragma pack(<n>) in effect when the first
60 #pragma pack(push,<n>) is encountered, this stores the value of
61 maximum_field_alignment in effect. When the final pop_alignment()
62 happens, we restore the value to this, not to a value of 0 for
63 maximum_field_alignment. Value is in bits. */
64 static int default_alignment;
65 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = *(alignment_stack == NULL \
66 ? &default_alignment \
67 : &alignment_stack->alignment) = (ALIGN))
68
69 static void push_alignment (int, tree);
70 static void pop_alignment (tree);
71
72 /* Push an alignment value onto the stack. */
73 static void
74 push_alignment (int alignment, tree id)
75 {
76 align_stack * entry;
77
78 entry = GGC_NEW (align_stack);
79
80 entry->alignment = alignment;
81 entry->id = id;
82 entry->prev = alignment_stack;
83
84 /* The current value of maximum_field_alignment is not necessarily
85 0 since there may be a #pragma pack(<n>) in effect; remember it
86 so that we can restore it after the final #pragma pop(). */
87 if (alignment_stack == NULL)
88 default_alignment = maximum_field_alignment;
89
90 alignment_stack = entry;
91
92 maximum_field_alignment = alignment;
93 }
94
95 /* Undo a push of an alignment onto the stack. */
96 static void
97 pop_alignment (tree id)
98 {
99 align_stack * entry;
100
101 if (alignment_stack == NULL)
102 GCC_BAD ("#pragma pack (pop) encountered without matching #pragma pack (push)");
103
104 /* If we got an identifier, strip away everything above the target
105 entry so that the next step will restore the state just below it. */
106 if (id)
107 {
108 for (entry = alignment_stack; entry; entry = entry->prev)
109 if (entry->id == id)
110 {
111 alignment_stack = entry;
112 break;
113 }
114 if (entry == NULL)
115 warning (OPT_Wpragmas, "\
116 #pragma pack(pop, %s) encountered without matching #pragma pack(push, %s)"
117 , IDENTIFIER_POINTER (id), IDENTIFIER_POINTER (id));
118 }
119
120 entry = alignment_stack->prev;
121
122 maximum_field_alignment = entry ? entry->alignment : default_alignment;
123
124 alignment_stack = entry;
125 }
126 #else /* not HANDLE_PRAGMA_PACK_PUSH_POP */
127 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = (ALIGN))
128 #define push_alignment(ID, N) \
129 GCC_BAD ("#pragma pack(push[, id], <n>) is not supported on this target")
130 #define pop_alignment(ID) \
131 GCC_BAD ("#pragma pack(pop[, id], <n>) is not supported on this target")
132 #endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
133
134 /* #pragma pack ()
135 #pragma pack (N)
136
137 #pragma pack (push)
138 #pragma pack (push, N)
139 #pragma pack (push, ID)
140 #pragma pack (push, ID, N)
141 #pragma pack (pop)
142 #pragma pack (pop, ID) */
143 static void
144 handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy))
145 {
146 tree x, id = 0;
147 int align = -1;
148 enum cpp_ttype token;
149 enum { set, push, pop } action;
150
151 if (pragma_lex (&x) != CPP_OPEN_PAREN)
152 GCC_BAD ("missing %<(%> after %<#pragma pack%> - ignored");
153
154 token = pragma_lex (&x);
155 if (token == CPP_CLOSE_PAREN)
156 {
157 action = set;
158 align = initial_max_fld_align;
159 }
160 else if (token == CPP_NUMBER)
161 {
162 if (TREE_CODE (x) != INTEGER_CST)
163 GCC_BAD ("invalid constant in %<#pragma pack%> - ignored");
164 align = TREE_INT_CST_LOW (x);
165 action = set;
166 if (pragma_lex (&x) != CPP_CLOSE_PAREN)
167 GCC_BAD ("malformed %<#pragma pack%> - ignored");
168 }
169 else if (token == CPP_NAME)
170 {
171 #define GCC_BAD_ACTION do { if (action != pop) \
172 GCC_BAD ("malformed %<#pragma pack(push[, id][, <n>])%> - ignored"); \
173 else \
174 GCC_BAD ("malformed %<#pragma pack(pop[, id])%> - ignored"); \
175 } while (0)
176
177 const char *op = IDENTIFIER_POINTER (x);
178 if (!strcmp (op, "push"))
179 action = push;
180 else if (!strcmp (op, "pop"))
181 action = pop;
182 else
183 GCC_BAD2 ("unknown action %qs for %<#pragma pack%> - ignored", op);
184
185 while ((token = pragma_lex (&x)) == CPP_COMMA)
186 {
187 token = pragma_lex (&x);
188 if (token == CPP_NAME && id == 0)
189 {
190 id = x;
191 }
192 else if (token == CPP_NUMBER && action == push && align == -1)
193 {
194 if (TREE_CODE (x) != INTEGER_CST)
195 GCC_BAD ("invalid constant in %<#pragma pack%> - ignored");
196 align = TREE_INT_CST_LOW (x);
197 if (align == -1)
198 action = set;
199 }
200 else
201 GCC_BAD_ACTION;
202 }
203
204 if (token != CPP_CLOSE_PAREN)
205 GCC_BAD_ACTION;
206 #undef GCC_BAD_ACTION
207 }
208 else
209 GCC_BAD ("malformed %<#pragma pack%> - ignored");
210
211 if (pragma_lex (&x) != CPP_EOF)
212 warning (OPT_Wpragmas, "junk at end of %<#pragma pack%>");
213
214 if (flag_pack_struct)
215 GCC_BAD ("#pragma pack has no effect with -fpack-struct - ignored");
216
217 if (action != pop)
218 switch (align)
219 {
220 case 0:
221 case 1:
222 case 2:
223 case 4:
224 case 8:
225 case 16:
226 align *= BITS_PER_UNIT;
227 break;
228 case -1:
229 if (action == push)
230 {
231 align = maximum_field_alignment;
232 break;
233 }
234 default:
235 GCC_BAD2 ("alignment must be a small power of two, not %d", align);
236 }
237
238 switch (action)
239 {
240 case set: SET_GLOBAL_ALIGNMENT (align); break;
241 case push: push_alignment (align, id); break;
242 case pop: pop_alignment (id); break;
243 }
244 }
245 #endif /* HANDLE_PRAGMA_PACK */
246
247 struct def_pragma_macro_value GTY(())
248 {
249 struct def_pragma_macro_value *prev;
250 cpp_macro *value;
251 };
252
253 struct def_pragma_macro GTY(())
254 {
255 hashval_t hash;
256 const char *name;
257 struct def_pragma_macro_value value;
258 };
259
260 static GTY((param_is (struct def_pragma_macro))) htab_t pushed_macro_table;
261
262 #ifdef HANDLE_PRAGMA_PUSH_POP_MACRO
263 /* Hash table control functions for pushed_macro_table. */
264 static hashval_t
265 dpm_hash (const void *p)
266 {
267 return ((const struct def_pragma_macro *)p)->hash;
268 }
269
270 static int
271 dpm_eq (const void *pa, const void *pb)
272 {
273 const struct def_pragma_macro *const a = (const struct def_pragma_macro *) pa,
274 *const b = (const struct def_pragma_macro *) pb;
275 return a->hash == b->hash && strcmp (a->name, b->name) == 0;
276 }
277
278 /* #pragma push_macro("MACRO_NAME")
279 #pragma pop_macro("MACRO_NAME") */
280
281 static void
282 handle_pragma_push_macro (cpp_reader *reader)
283 {
284 tree x, id = 0;
285 enum cpp_ttype token;
286 struct def_pragma_macro dummy, *c;
287 const char *macroname;
288 void **slot;
289
290 if (pragma_lex (&x) != CPP_OPEN_PAREN)
291 GCC_BAD ("missing %<(%> after %<#pragma push_macro%> - ignored");
292
293 token = pragma_lex (&id);
294
295 /* Silently ignore */
296 if (token == CPP_CLOSE_PAREN)
297 return;
298 if (token != CPP_STRING)
299 GCC_BAD ("invalid constant in %<#pragma push_macro%> - ignored");
300
301 if (pragma_lex (&x) != CPP_CLOSE_PAREN)
302 GCC_BAD ("missing %<)%> after %<#pragma push_macro%> - ignored");
303
304 if (pragma_lex (&x) != CPP_EOF)
305 warning (OPT_Wpragmas, "junk at end of %<#pragma push_macro%>");
306
307 /* Check for empty string, and silently ignore. */
308 if (TREE_STRING_LENGTH (id) < 1)
309 return;
310 macroname = TREE_STRING_POINTER (id);
311
312 if (pushed_macro_table == NULL)
313 pushed_macro_table = htab_create_ggc (15, dpm_hash, dpm_eq, 0);
314
315 dummy.hash = htab_hash_string (macroname);
316 dummy.name = macroname;
317 slot = htab_find_slot_with_hash (pushed_macro_table, &dummy,
318 dummy.hash, INSERT);
319 c = (struct def_pragma_macro *) *slot;
320 if (c == NULL)
321 {
322 *slot = c = GGC_NEW (struct def_pragma_macro);
323 c->hash = dummy.hash;
324 c->name = ggc_alloc_string (macroname, TREE_STRING_LENGTH (id) - 1);
325 c->value.prev = NULL;
326 }
327 else
328 {
329 struct def_pragma_macro_value *v;
330 v = GGC_NEW (struct def_pragma_macro_value);
331 *v = c->value;
332 c->value.prev = v;
333 }
334
335 c->value.value = cpp_push_definition (reader, macroname);
336 }
337
338 static void
339 handle_pragma_pop_macro (cpp_reader *reader)
340 {
341 tree x, id = 0;
342 enum cpp_ttype token;
343 struct def_pragma_macro dummy, *c;
344 const char *macroname;
345 void **slot = NULL;
346
347 if (pragma_lex (&x) != CPP_OPEN_PAREN)
348 GCC_BAD ("missing %<(%> after %<#pragma pop_macro%> - ignored");
349
350 token = pragma_lex (&id);
351
352 /* Silently ignore */
353 if (token == CPP_CLOSE_PAREN)
354 return;
355 if (token != CPP_STRING)
356 GCC_BAD ("invalid constant in %<#pragma pop_macro%> - ignored");
357
358 if (pragma_lex (&x) != CPP_CLOSE_PAREN)
359 GCC_BAD ("missing %<)%> after %<#pragma pop_macro%> - ignored");
360
361 if (pragma_lex (&x) != CPP_EOF)
362 warning (OPT_Wpragmas, "junk at end of %<#pragma pop_macro%>");
363
364 /* Check for empty string, and silently ignore. */
365 if (TREE_STRING_LENGTH (id) < 1)
366 return;
367 macroname = TREE_STRING_POINTER (id);
368
369 dummy.hash = htab_hash_string (macroname);
370 dummy.name = macroname;
371 if (pushed_macro_table)
372 slot = htab_find_slot_with_hash (pushed_macro_table, &dummy,
373 dummy.hash, NO_INSERT);
374 if (slot == NULL)
375 return;
376 c = (struct def_pragma_macro *) *slot;
377
378 cpp_pop_definition (reader, c->name, c->value.value);
379
380 if (c->value.prev)
381 c->value = *c->value.prev;
382 else
383 htab_clear_slot (pushed_macro_table, slot);
384 }
385 #endif /* HANDLE_PRAGMA_PUSH_POP_MACRO */
386
387 static GTY(()) tree pending_weaks;
388
389 #ifdef HANDLE_PRAGMA_WEAK
390 static void apply_pragma_weak (tree, tree);
391 static void handle_pragma_weak (cpp_reader *);
392
393 static void
394 apply_pragma_weak (tree decl, tree value)
395 {
396 if (value)
397 {
398 value = build_string (IDENTIFIER_LENGTH (value),
399 IDENTIFIER_POINTER (value));
400 decl_attributes (&decl, build_tree_list (get_identifier ("alias"),
401 build_tree_list (NULL, value)),
402 0);
403 }
404
405 if (SUPPORTS_WEAK && DECL_EXTERNAL (decl) && TREE_USED (decl)
406 && !DECL_WEAK (decl) /* Don't complain about a redundant #pragma. */
407 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
408 warning (OPT_Wpragmas, "applying #pragma weak %q+D after first use "
409 "results in unspecified behavior", decl);
410
411 declare_weak (decl);
412 }
413
414 void
415 maybe_apply_pragma_weak (tree decl)
416 {
417 tree *p, t, id;
418
419 /* Avoid asking for DECL_ASSEMBLER_NAME when it's not needed. */
420
421 /* No weak symbols pending, take the short-cut. */
422 if (!pending_weaks)
423 return;
424 /* If it's not visible outside this file, it doesn't matter whether
425 it's weak. */
426 if (!DECL_EXTERNAL (decl) && !TREE_PUBLIC (decl))
427 return;
428 /* If it's not a function or a variable, it can't be weak.
429 FIXME: what kinds of things are visible outside this file but
430 aren't functions or variables? Should this be an assert instead? */
431 if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
432 return;
433
434 id = DECL_ASSEMBLER_NAME (decl);
435
436 for (p = &pending_weaks; (t = *p) ; p = &TREE_CHAIN (t))
437 if (id == TREE_PURPOSE (t))
438 {
439 apply_pragma_weak (decl, TREE_VALUE (t));
440 *p = TREE_CHAIN (t);
441 break;
442 }
443 }
444
445 /* Process all "#pragma weak A = B" directives where we have not seen
446 a decl for A. */
447 void
448 maybe_apply_pending_pragma_weaks (void)
449 {
450 tree *p, t, alias_id, id, decl, *next;
451
452 for (p = &pending_weaks; (t = *p) ; p = next)
453 {
454 next = &TREE_CHAIN (t);
455 alias_id = TREE_PURPOSE (t);
456 id = TREE_VALUE (t);
457
458 if (TREE_VALUE (t) == NULL)
459 continue;
460
461 decl = build_decl (FUNCTION_DECL, alias_id, default_function_type);
462
463 DECL_ARTIFICIAL (decl) = 1;
464 TREE_PUBLIC (decl) = 1;
465 DECL_EXTERNAL (decl) = 1;
466 DECL_WEAK (decl) = 1;
467
468 assemble_alias (decl, id);
469 }
470 }
471
472 /* #pragma weak name [= value] */
473 static void
474 handle_pragma_weak (cpp_reader * ARG_UNUSED (dummy))
475 {
476 tree name, value, x, decl;
477 enum cpp_ttype t;
478
479 value = 0;
480
481 if (pragma_lex (&name) != CPP_NAME)
482 GCC_BAD ("malformed #pragma weak, ignored");
483 t = pragma_lex (&x);
484 if (t == CPP_EQ)
485 {
486 if (pragma_lex (&value) != CPP_NAME)
487 GCC_BAD ("malformed #pragma weak, ignored");
488 t = pragma_lex (&x);
489 }
490 if (t != CPP_EOF)
491 warning (OPT_Wpragmas, "junk at end of %<#pragma weak%>");
492
493 decl = identifier_global_value (name);
494 if (decl && DECL_P (decl))
495 {
496 apply_pragma_weak (decl, value);
497 if (value)
498 assemble_alias (decl, value);
499 }
500 else
501 pending_weaks = tree_cons (name, value, pending_weaks);
502 }
503 #else
504 void
505 maybe_apply_pragma_weak (tree ARG_UNUSED (decl))
506 {
507 }
508
509 void
510 maybe_apply_pending_pragma_weaks (void)
511 {
512 }
513 #endif /* HANDLE_PRAGMA_WEAK */
514
515 /* GCC supports two #pragma directives for renaming the external
516 symbol associated with a declaration (DECL_ASSEMBLER_NAME), for
517 compatibility with the Solaris and Tru64 system headers. GCC also
518 has its own notation for this, __asm__("name") annotations.
519
520 Corner cases of these features and their interaction:
521
522 1) Both pragmas silently apply only to declarations with external
523 linkage (that is, TREE_PUBLIC || DECL_EXTERNAL). Asm labels
524 do not have this restriction.
525
526 2) In C++, both #pragmas silently apply only to extern "C" declarations.
527 Asm labels do not have this restriction.
528
529 3) If any of the three ways of changing DECL_ASSEMBLER_NAME is
530 applied to a decl whose DECL_ASSEMBLER_NAME is already set, and the
531 new name is different, a warning issues and the name does not change.
532
533 4) The "source name" for #pragma redefine_extname is the DECL_NAME,
534 *not* the DECL_ASSEMBLER_NAME.
535
536 5) If #pragma extern_prefix is in effect and a declaration occurs
537 with an __asm__ name, the #pragma extern_prefix is silently
538 ignored for that declaration.
539
540 6) If #pragma extern_prefix and #pragma redefine_extname apply to
541 the same declaration, whichever triggered first wins, and a warning
542 is issued. (We would like to have #pragma redefine_extname always
543 win, but it can appear either before or after the declaration, and
544 if it appears afterward, we have no way of knowing whether a modified
545 DECL_ASSEMBLER_NAME is due to #pragma extern_prefix.) */
546
547 static GTY(()) tree pending_redefine_extname;
548
549 static void handle_pragma_redefine_extname (cpp_reader *);
550
551 /* #pragma redefine_extname oldname newname */
552 static void
553 handle_pragma_redefine_extname (cpp_reader * ARG_UNUSED (dummy))
554 {
555 tree oldname, newname, decl, x;
556 enum cpp_ttype t;
557
558 if (pragma_lex (&oldname) != CPP_NAME)
559 GCC_BAD ("malformed #pragma redefine_extname, ignored");
560 if (pragma_lex (&newname) != CPP_NAME)
561 GCC_BAD ("malformed #pragma redefine_extname, ignored");
562 t = pragma_lex (&x);
563 if (t != CPP_EOF)
564 warning (OPT_Wpragmas, "junk at end of %<#pragma redefine_extname%>");
565
566 if (!flag_mudflap && !targetm.handle_pragma_redefine_extname)
567 {
568 if (warn_unknown_pragmas > in_system_header)
569 warning (OPT_Wunknown_pragmas,
570 "#pragma redefine_extname not supported on this target");
571 return;
572 }
573
574 decl = identifier_global_value (oldname);
575 if (decl
576 && (TREE_PUBLIC (decl) || DECL_EXTERNAL (decl))
577 && (TREE_CODE (decl) == FUNCTION_DECL
578 || TREE_CODE (decl) == VAR_DECL)
579 && has_c_linkage (decl))
580 {
581 if (DECL_ASSEMBLER_NAME_SET_P (decl))
582 {
583 const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
584 name = targetm.strip_name_encoding (name);
585
586 if (strcmp (name, IDENTIFIER_POINTER (newname)))
587 warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
588 "conflict with previous rename");
589 }
590 else
591 change_decl_assembler_name (decl, newname);
592 }
593 else
594 /* We have to add this to the rename list even if there's already
595 a global value that doesn't meet the above criteria, because in
596 C++ "struct foo {...};" puts "foo" in the current namespace but
597 does *not* conflict with a subsequent declaration of a function
598 or variable foo. See g++.dg/other/pragma-re-2.C. */
599 add_to_renaming_pragma_list (oldname, newname);
600 }
601
602 /* This is called from here and from ia64.c. */
603 void
604 add_to_renaming_pragma_list (tree oldname, tree newname)
605 {
606 tree previous = purpose_member (oldname, pending_redefine_extname);
607 if (previous)
608 {
609 if (TREE_VALUE (previous) != newname)
610 warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
611 "conflict with previous #pragma redefine_extname");
612 return;
613 }
614
615 pending_redefine_extname
616 = tree_cons (oldname, newname, pending_redefine_extname);
617 }
618
619 static GTY(()) tree pragma_extern_prefix;
620
621 /* #pragma extern_prefix "prefix" */
622 static void
623 handle_pragma_extern_prefix (cpp_reader * ARG_UNUSED (dummy))
624 {
625 tree prefix, x;
626 enum cpp_ttype t;
627
628 if (pragma_lex (&prefix) != CPP_STRING)
629 GCC_BAD ("malformed #pragma extern_prefix, ignored");
630 t = pragma_lex (&x);
631 if (t != CPP_EOF)
632 warning (OPT_Wpragmas, "junk at end of %<#pragma extern_prefix%>");
633
634 if (targetm.handle_pragma_extern_prefix)
635 /* Note that the length includes the null terminator. */
636 pragma_extern_prefix = (TREE_STRING_LENGTH (prefix) > 1 ? prefix : NULL);
637 else if (warn_unknown_pragmas > in_system_header)
638 warning (OPT_Wunknown_pragmas,
639 "#pragma extern_prefix not supported on this target");
640 }
641
642 /* Hook from the front ends to apply the results of one of the preceding
643 pragmas that rename variables. */
644
645 tree
646 maybe_apply_renaming_pragma (tree decl, tree asmname)
647 {
648 tree *p, t;
649
650 /* The renaming pragmas are only applied to declarations with
651 external linkage. */
652 if ((TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
653 || (!TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
654 || !has_c_linkage (decl))
655 return asmname;
656
657 /* If the DECL_ASSEMBLER_NAME is already set, it does not change,
658 but we may warn about a rename that conflicts. */
659 if (DECL_ASSEMBLER_NAME_SET_P (decl))
660 {
661 const char *oldname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
662 oldname = targetm.strip_name_encoding (oldname);
663
664 if (asmname && strcmp (TREE_STRING_POINTER (asmname), oldname))
665 warning (OPT_Wpragmas, "asm declaration ignored due to "
666 "conflict with previous rename");
667
668 /* Take any pending redefine_extname off the list. */
669 for (p = &pending_redefine_extname; (t = *p); p = &TREE_CHAIN (t))
670 if (DECL_NAME (decl) == TREE_PURPOSE (t))
671 {
672 /* Only warn if there is a conflict. */
673 if (strcmp (IDENTIFIER_POINTER (TREE_VALUE (t)), oldname))
674 warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
675 "conflict with previous rename");
676
677 *p = TREE_CHAIN (t);
678 break;
679 }
680 return 0;
681 }
682
683 /* Find out if we have a pending #pragma redefine_extname. */
684 for (p = &pending_redefine_extname; (t = *p); p = &TREE_CHAIN (t))
685 if (DECL_NAME (decl) == TREE_PURPOSE (t))
686 {
687 tree newname = TREE_VALUE (t);
688 *p = TREE_CHAIN (t);
689
690 /* If we already have an asmname, #pragma redefine_extname is
691 ignored (with a warning if it conflicts). */
692 if (asmname)
693 {
694 if (strcmp (TREE_STRING_POINTER (asmname),
695 IDENTIFIER_POINTER (newname)) != 0)
696 warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
697 "conflict with __asm__ declaration");
698 return asmname;
699 }
700
701 /* Otherwise we use what we've got; #pragma extern_prefix is
702 silently ignored. */
703 return build_string (IDENTIFIER_LENGTH (newname),
704 IDENTIFIER_POINTER (newname));
705 }
706
707 /* If we've got an asmname, #pragma extern_prefix is silently ignored. */
708 if (asmname)
709 return asmname;
710
711 /* If #pragma extern_prefix is in effect, apply it. */
712 if (pragma_extern_prefix)
713 {
714 const char *prefix = TREE_STRING_POINTER (pragma_extern_prefix);
715 size_t plen = TREE_STRING_LENGTH (pragma_extern_prefix) - 1;
716
717 const char *id = IDENTIFIER_POINTER (DECL_NAME (decl));
718 size_t ilen = IDENTIFIER_LENGTH (DECL_NAME (decl));
719
720 char *newname = (char *) alloca (plen + ilen + 1);
721
722 memcpy (newname, prefix, plen);
723 memcpy (newname + plen, id, ilen + 1);
724
725 return build_string (plen + ilen, newname);
726 }
727
728 /* Nada. */
729 return 0;
730 }
731
732
733 #ifdef HANDLE_PRAGMA_VISIBILITY
734 static void handle_pragma_visibility (cpp_reader *);
735
736 typedef enum symbol_visibility visibility;
737 DEF_VEC_I (visibility);
738 DEF_VEC_ALLOC_I (visibility, heap);
739 static VEC (visibility, heap) *visstack;
740
741 /* Push the visibility indicated by STR onto the top of the #pragma
742 visibility stack. */
743
744 void
745 push_visibility (const char *str)
746 {
747 VEC_safe_push (visibility, heap, visstack,
748 default_visibility);
749 if (!strcmp (str, "default"))
750 default_visibility = VISIBILITY_DEFAULT;
751 else if (!strcmp (str, "internal"))
752 default_visibility = VISIBILITY_INTERNAL;
753 else if (!strcmp (str, "hidden"))
754 default_visibility = VISIBILITY_HIDDEN;
755 else if (!strcmp (str, "protected"))
756 default_visibility = VISIBILITY_PROTECTED;
757 else
758 GCC_BAD ("#pragma GCC visibility push() must specify default, internal, hidden or protected");
759 visibility_options.inpragma = 1;
760 }
761
762 /* Pop a level of the #pragma visibility stack. */
763
764 void
765 pop_visibility (void)
766 {
767 default_visibility = VEC_pop (visibility, visstack);
768 visibility_options.inpragma
769 = VEC_length (visibility, visstack) != 0;
770 }
771
772 /* Sets the default visibility for symbols to something other than that
773 specified on the command line. */
774
775 static void
776 handle_pragma_visibility (cpp_reader *dummy ATTRIBUTE_UNUSED)
777 {
778 /* Form is #pragma GCC visibility push(hidden)|pop */
779 tree x;
780 enum cpp_ttype token;
781 enum { bad, push, pop } action = bad;
782
783 token = pragma_lex (&x);
784 if (token == CPP_NAME)
785 {
786 const char *op = IDENTIFIER_POINTER (x);
787 if (!strcmp (op, "push"))
788 action = push;
789 else if (!strcmp (op, "pop"))
790 action = pop;
791 }
792 if (bad == action)
793 GCC_BAD ("#pragma GCC visibility must be followed by push or pop");
794 else
795 {
796 if (pop == action)
797 {
798 if (!VEC_length (visibility, visstack))
799 GCC_BAD ("no matching push for %<#pragma GCC visibility pop%>");
800 else
801 pop_visibility ();
802 }
803 else
804 {
805 if (pragma_lex (&x) != CPP_OPEN_PAREN)
806 GCC_BAD ("missing %<(%> after %<#pragma GCC visibility push%> - ignored");
807 token = pragma_lex (&x);
808 if (token != CPP_NAME)
809 GCC_BAD ("malformed #pragma GCC visibility push");
810 else
811 push_visibility (IDENTIFIER_POINTER (x));
812 if (pragma_lex (&x) != CPP_CLOSE_PAREN)
813 GCC_BAD ("missing %<(%> after %<#pragma GCC visibility push%> - ignored");
814 }
815 }
816 if (pragma_lex (&x) != CPP_EOF)
817 warning (OPT_Wpragmas, "junk at end of %<#pragma GCC visibility%>");
818 }
819
820 #endif
821
822 static void
823 handle_pragma_diagnostic(cpp_reader *ARG_UNUSED(dummy))
824 {
825 const char *kind_string, *option_string;
826 unsigned int option_index;
827 enum cpp_ttype token;
828 diagnostic_t kind;
829 tree x;
830
831 if (cfun)
832 {
833 error ("#pragma GCC diagnostic not allowed inside functions");
834 return;
835 }
836
837 token = pragma_lex (&x);
838 if (token != CPP_NAME)
839 GCC_BAD ("missing [error|warning|ignored] after %<#pragma GCC diagnostic%>");
840 kind_string = IDENTIFIER_POINTER (x);
841 if (strcmp (kind_string, "error") == 0)
842 kind = DK_ERROR;
843 else if (strcmp (kind_string, "warning") == 0)
844 kind = DK_WARNING;
845 else if (strcmp (kind_string, "ignored") == 0)
846 kind = DK_IGNORED;
847 else
848 GCC_BAD ("expected [error|warning|ignored] after %<#pragma GCC diagnostic%>");
849
850 token = pragma_lex (&x);
851 if (token != CPP_STRING)
852 GCC_BAD ("missing option after %<#pragma GCC diagnostic%> kind");
853 option_string = TREE_STRING_POINTER (x);
854 for (option_index = 0; option_index < cl_options_count; option_index++)
855 if (strcmp (cl_options[option_index].opt_text, option_string) == 0)
856 {
857 /* This overrides -Werror, for example. */
858 diagnostic_classify_diagnostic (global_dc, option_index, kind);
859 /* This makes sure the option is enabled, like -Wfoo would do. */
860 if (cl_options[option_index].var_type == CLVC_BOOLEAN
861 && cl_options[option_index].flag_var
862 && kind != DK_IGNORED)
863 *(int *) cl_options[option_index].flag_var = 1;
864 return;
865 }
866 GCC_BAD ("unknown option after %<#pragma GCC diagnostic%> kind");
867 }
868
869 /* Parse #pragma GCC target (xxx) to set target specific options. */
870 static void
871 handle_pragma_target(cpp_reader *ARG_UNUSED(dummy))
872 {
873 enum cpp_ttype token;
874 tree x;
875 bool close_paren_needed_p = false;
876
877 if (cfun)
878 {
879 error ("#pragma GCC option is not allowed inside functions");
880 return;
881 }
882
883 token = pragma_lex (&x);
884 if (token == CPP_OPEN_PAREN)
885 {
886 close_paren_needed_p = true;
887 token = pragma_lex (&x);
888 }
889
890 if (token != CPP_STRING)
891 {
892 GCC_BAD ("%<#pragma GCC option%> is not a string");
893 return;
894 }
895
896 /* Strings are user options. */
897 else
898 {
899 tree args = NULL_TREE;
900
901 do
902 {
903 /* Build up the strings now as a tree linked list. Skip empty
904 strings. */
905 if (TREE_STRING_LENGTH (x) > 0)
906 args = tree_cons (NULL_TREE, x, args);
907
908 token = pragma_lex (&x);
909 while (token == CPP_COMMA)
910 token = pragma_lex (&x);
911 }
912 while (token == CPP_STRING);
913
914 if (close_paren_needed_p)
915 {
916 if (token == CPP_CLOSE_PAREN)
917 token = pragma_lex (&x);
918 else
919 GCC_BAD ("%<#pragma GCC target (string [,string]...)%> does "
920 "not have a final %<)%>.");
921 }
922
923 if (token != CPP_EOF)
924 {
925 error ("#pragma GCC target string... is badly formed");
926 return;
927 }
928
929 /* put arguments in the order the user typed them. */
930 args = nreverse (args);
931
932 if (targetm.target_option.pragma_parse (args, NULL_TREE))
933 current_target_pragma = args;
934 }
935 }
936
937 /* Handle #pragma GCC optimize to set optimization options. */
938 static void
939 handle_pragma_optimize (cpp_reader *ARG_UNUSED(dummy))
940 {
941 enum cpp_ttype token;
942 tree x;
943 bool close_paren_needed_p = false;
944 tree optimization_previous_node = optimization_current_node;
945
946 if (cfun)
947 {
948 error ("#pragma GCC optimize is not allowed inside functions");
949 return;
950 }
951
952 token = pragma_lex (&x);
953 if (token == CPP_OPEN_PAREN)
954 {
955 close_paren_needed_p = true;
956 token = pragma_lex (&x);
957 }
958
959 if (token != CPP_STRING && token != CPP_NUMBER)
960 {
961 GCC_BAD ("%<#pragma GCC optimize%> is not a string or number");
962 return;
963 }
964
965 /* Strings/numbers are user options. */
966 else
967 {
968 tree args = NULL_TREE;
969
970 do
971 {
972 /* Build up the numbers/strings now as a list. */
973 if (token != CPP_STRING || TREE_STRING_LENGTH (x) > 0)
974 args = tree_cons (NULL_TREE, x, args);
975
976 token = pragma_lex (&x);
977 while (token == CPP_COMMA)
978 token = pragma_lex (&x);
979 }
980 while (token == CPP_STRING || token == CPP_NUMBER);
981
982 if (close_paren_needed_p)
983 {
984 if (token == CPP_CLOSE_PAREN)
985 token = pragma_lex (&x);
986 else
987 GCC_BAD ("%<#pragma GCC optimize (string [,string]...)%> does "
988 "not have a final %<)%>.");
989 }
990
991 if (token != CPP_EOF)
992 {
993 error ("#pragma GCC optimize string... is badly formed");
994 return;
995 }
996
997 /* put arguments in the order the user typed them. */
998 args = nreverse (args);
999
1000 parse_optimize_options (args, false);
1001 current_optimize_pragma = chainon (current_optimize_pragma, args);
1002 optimization_current_node = build_optimization_node ();
1003 c_cpp_builtins_optimize_pragma (parse_in,
1004 optimization_previous_node,
1005 optimization_current_node);
1006 }
1007 }
1008
1009 /* Stack of the #pragma GCC options created with #pragma GCC push_option. Save
1010 both the binary representation of the options and the TREE_LIST of
1011 strings that will be added to the function's attribute list. */
1012 typedef struct opt_stack GTY(())
1013 {
1014 struct opt_stack *prev;
1015 tree target_binary;
1016 tree target_strings;
1017 tree optimize_binary;
1018 tree optimize_strings;
1019 } opt_stack;
1020
1021 static GTY(()) struct opt_stack * options_stack;
1022
1023 /* Handle #pragma GCC push_options to save the current target and optimization
1024 options. */
1025
1026 static void
1027 handle_pragma_push_options (cpp_reader *ARG_UNUSED(dummy))
1028 {
1029 enum cpp_ttype token;
1030 tree x = 0;
1031 opt_stack *p;
1032
1033 token = pragma_lex (&x);
1034 if (token != CPP_EOF)
1035 {
1036 warning (OPT_Wpragmas, "junk at end of %<#pragma push_options%>");
1037 return;
1038 }
1039
1040 p = GGC_NEW (opt_stack);
1041 p->prev = options_stack;
1042 options_stack = p;
1043
1044 /* Save optimization and target flags in binary format. */
1045 p->optimize_binary = build_optimization_node ();
1046 p->target_binary = build_target_option_node ();
1047
1048 /* Save optimization and target flags in string list format. */
1049 p->optimize_strings = copy_list (current_optimize_pragma);
1050 p->target_strings = copy_list (current_target_pragma);
1051 }
1052
1053 /* Handle #pragma GCC pop_options to restore the current target and
1054 optimization options from a previous push_options. */
1055
1056 static void
1057 handle_pragma_pop_options (cpp_reader *ARG_UNUSED(dummy))
1058 {
1059 enum cpp_ttype token;
1060 tree x = 0;
1061 opt_stack *p;
1062
1063 token = pragma_lex (&x);
1064 if (token != CPP_EOF)
1065 {
1066 warning (OPT_Wpragmas, "junk at end of %<#pragma pop_options%>");
1067 return;
1068 }
1069
1070 if (! options_stack)
1071 {
1072 warning (OPT_Wpragmas,
1073 "%<#pragma GCC pop_options%> without a corresponding "
1074 "%<#pragma GCC push_options%>");
1075 return;
1076 }
1077
1078 p = options_stack;
1079 options_stack = p->prev;
1080
1081 if (p->target_binary != target_option_current_node)
1082 {
1083 (void) targetm.target_option.pragma_parse (NULL_TREE, p->target_binary);
1084 target_option_current_node = p->target_binary;
1085 }
1086
1087 if (p->optimize_binary != optimization_current_node)
1088 {
1089 tree old_optimize = optimization_current_node;
1090 cl_optimization_restore (TREE_OPTIMIZATION (p->optimize_binary));
1091 c_cpp_builtins_optimize_pragma (parse_in, old_optimize,
1092 p->optimize_binary);
1093 optimization_current_node = p->optimize_binary;
1094 }
1095
1096 current_target_pragma = p->target_strings;
1097 current_optimize_pragma = p->optimize_strings;
1098 }
1099
1100 /* Handle #pragma GCC reset_options to restore the current target and
1101 optimization options to the original options used on the command line. */
1102
1103 static void
1104 handle_pragma_reset_options (cpp_reader *ARG_UNUSED(dummy))
1105 {
1106 enum cpp_ttype token;
1107 tree x = 0;
1108 tree new_optimize = optimization_default_node;
1109 tree new_target = target_option_default_node;
1110
1111 token = pragma_lex (&x);
1112 if (token != CPP_EOF)
1113 {
1114 warning (OPT_Wpragmas, "junk at end of %<#pragma reset_options%>");
1115 return;
1116 }
1117
1118 if (new_target != target_option_current_node)
1119 {
1120 (void) targetm.target_option.pragma_parse (NULL_TREE, new_target);
1121 target_option_current_node = new_target;
1122 }
1123
1124 if (new_optimize != optimization_current_node)
1125 {
1126 tree old_optimize = optimization_current_node;
1127 cl_optimization_restore (TREE_OPTIMIZATION (new_optimize));
1128 c_cpp_builtins_optimize_pragma (parse_in, old_optimize, new_optimize);
1129 optimization_current_node = new_optimize;
1130 }
1131
1132 current_target_pragma = NULL_TREE;
1133 current_optimize_pragma = NULL_TREE;
1134 }
1135
1136 /* Print a plain user-specified message. */
1137
1138 static void
1139 handle_pragma_message (cpp_reader *ARG_UNUSED(dummy))
1140 {
1141 enum cpp_ttype token;
1142 tree x, message = 0;
1143
1144 token = pragma_lex (&x);
1145 if (token == CPP_OPEN_PAREN)
1146 {
1147 token = pragma_lex (&x);
1148 if (token == CPP_STRING)
1149 message = x;
1150 else
1151 GCC_BAD ("expected a string after %<#pragma message%>");
1152 if (pragma_lex (&x) != CPP_CLOSE_PAREN)
1153 GCC_BAD ("malformed %<#pragma message%>, ignored");
1154 }
1155 else if (token == CPP_STRING)
1156 message = x;
1157 else
1158 GCC_BAD ("expected a string after %<#pragma message%>");
1159
1160 gcc_assert (message);
1161
1162 if (pragma_lex (&x) != CPP_EOF)
1163 warning (OPT_Wpragmas, "junk at end of %<#pragma message%>");
1164
1165 if (TREE_STRING_LENGTH (message) > 1)
1166 inform (input_location, "#pragma message: %s", TREE_STRING_POINTER (message));
1167 }
1168
1169 /* A vector of registered pragma callbacks. */
1170
1171 DEF_VEC_O (pragma_handler);
1172 DEF_VEC_ALLOC_O (pragma_handler, heap);
1173
1174 static VEC(pragma_handler, heap) *registered_pragmas;
1175
1176 typedef struct
1177 {
1178 const char *space;
1179 const char *name;
1180 } pragma_ns_name;
1181
1182 DEF_VEC_O (pragma_ns_name);
1183 DEF_VEC_ALLOC_O (pragma_ns_name, heap);
1184
1185 static VEC(pragma_ns_name, heap) *registered_pp_pragmas;
1186
1187 struct omp_pragma_def { const char *name; unsigned int id; };
1188 static const struct omp_pragma_def omp_pragmas[] = {
1189 { "atomic", PRAGMA_OMP_ATOMIC },
1190 { "barrier", PRAGMA_OMP_BARRIER },
1191 { "critical", PRAGMA_OMP_CRITICAL },
1192 { "flush", PRAGMA_OMP_FLUSH },
1193 { "for", PRAGMA_OMP_FOR },
1194 { "master", PRAGMA_OMP_MASTER },
1195 { "ordered", PRAGMA_OMP_ORDERED },
1196 { "parallel", PRAGMA_OMP_PARALLEL },
1197 { "section", PRAGMA_OMP_SECTION },
1198 { "sections", PRAGMA_OMP_SECTIONS },
1199 { "single", PRAGMA_OMP_SINGLE },
1200 { "task", PRAGMA_OMP_TASK },
1201 { "taskwait", PRAGMA_OMP_TASKWAIT },
1202 { "threadprivate", PRAGMA_OMP_THREADPRIVATE }
1203 };
1204
1205 void
1206 c_pp_lookup_pragma (unsigned int id, const char **space, const char **name)
1207 {
1208 const int n_omp_pragmas = sizeof (omp_pragmas) / sizeof (*omp_pragmas);
1209 int i;
1210
1211 for (i = 0; i < n_omp_pragmas; ++i)
1212 if (omp_pragmas[i].id == id)
1213 {
1214 *space = "omp";
1215 *name = omp_pragmas[i].name;
1216 return;
1217 }
1218
1219 if (id >= PRAGMA_FIRST_EXTERNAL
1220 && (id < PRAGMA_FIRST_EXTERNAL
1221 + VEC_length (pragma_ns_name, registered_pp_pragmas)))
1222 {
1223 *space = VEC_index (pragma_ns_name, registered_pp_pragmas,
1224 id - PRAGMA_FIRST_EXTERNAL)->space;
1225 *name = VEC_index (pragma_ns_name, registered_pp_pragmas,
1226 id - PRAGMA_FIRST_EXTERNAL)->name;
1227 return;
1228 }
1229
1230 gcc_unreachable ();
1231 }
1232
1233 /* Front-end wrappers for pragma registration to avoid dragging
1234 cpplib.h in almost everywhere. */
1235
1236 static void
1237 c_register_pragma_1 (const char *space, const char *name,
1238 pragma_handler handler, bool allow_expansion)
1239 {
1240 unsigned id;
1241
1242 if (flag_preprocess_only)
1243 {
1244 pragma_ns_name ns_name;
1245
1246 if (!allow_expansion)
1247 return;
1248
1249 ns_name.space = space;
1250 ns_name.name = name;
1251 VEC_safe_push (pragma_ns_name, heap, registered_pp_pragmas, &ns_name);
1252 id = VEC_length (pragma_ns_name, registered_pp_pragmas);
1253 id += PRAGMA_FIRST_EXTERNAL - 1;
1254 }
1255 else
1256 {
1257 VEC_safe_push (pragma_handler, heap, registered_pragmas, &handler);
1258 id = VEC_length (pragma_handler, registered_pragmas);
1259 id += PRAGMA_FIRST_EXTERNAL - 1;
1260
1261 /* The C++ front end allocates 6 bits in cp_token; the C front end
1262 allocates 7 bits in c_token. At present this is sufficient. */
1263 gcc_assert (id < 64);
1264 }
1265
1266 cpp_register_deferred_pragma (parse_in, space, name, id,
1267 allow_expansion, false);
1268 }
1269
1270 void
1271 c_register_pragma (const char *space, const char *name, pragma_handler handler)
1272 {
1273 c_register_pragma_1 (space, name, handler, false);
1274 }
1275
1276 void
1277 c_register_pragma_with_expansion (const char *space, const char *name,
1278 pragma_handler handler)
1279 {
1280 c_register_pragma_1 (space, name, handler, true);
1281 }
1282
1283 void
1284 c_invoke_pragma_handler (unsigned int id)
1285 {
1286 pragma_handler handler;
1287
1288 id -= PRAGMA_FIRST_EXTERNAL;
1289 handler = *VEC_index (pragma_handler, registered_pragmas, id);
1290
1291 handler (parse_in);
1292 }
1293
1294 /* Set up front-end pragmas. */
1295 void
1296 init_pragma (void)
1297 {
1298 if (flag_openmp)
1299 {
1300 const int n_omp_pragmas = sizeof (omp_pragmas) / sizeof (*omp_pragmas);
1301 int i;
1302
1303 for (i = 0; i < n_omp_pragmas; ++i)
1304 cpp_register_deferred_pragma (parse_in, "omp", omp_pragmas[i].name,
1305 omp_pragmas[i].id, true, true);
1306 }
1307
1308 if (!flag_preprocess_only)
1309 cpp_register_deferred_pragma (parse_in, "GCC", "pch_preprocess",
1310 PRAGMA_GCC_PCH_PREPROCESS, false, false);
1311
1312 #ifdef HANDLE_PRAGMA_PACK
1313 #ifdef HANDLE_PRAGMA_PACK_WITH_EXPANSION
1314 c_register_pragma_with_expansion (0, "pack", handle_pragma_pack);
1315 #else
1316 c_register_pragma (0, "pack", handle_pragma_pack);
1317 #endif
1318 #endif
1319 #ifdef HANDLE_PRAGMA_PUSH_POP_MACRO
1320 c_register_pragma (0 ,"push_macro", handle_pragma_push_macro);
1321 c_register_pragma (0 ,"pop_macro", handle_pragma_pop_macro);
1322 #endif
1323 #ifdef HANDLE_PRAGMA_WEAK
1324 c_register_pragma (0, "weak", handle_pragma_weak);
1325 #endif
1326 #ifdef HANDLE_PRAGMA_VISIBILITY
1327 c_register_pragma ("GCC", "visibility", handle_pragma_visibility);
1328 #endif
1329
1330 c_register_pragma ("GCC", "diagnostic", handle_pragma_diagnostic);
1331 c_register_pragma ("GCC", "target", handle_pragma_target);
1332 c_register_pragma ("GCC", "optimize", handle_pragma_optimize);
1333 c_register_pragma ("GCC", "push_options", handle_pragma_push_options);
1334 c_register_pragma ("GCC", "pop_options", handle_pragma_pop_options);
1335 c_register_pragma ("GCC", "reset_options", handle_pragma_reset_options);
1336
1337 c_register_pragma_with_expansion (0, "redefine_extname", handle_pragma_redefine_extname);
1338 c_register_pragma (0, "extern_prefix", handle_pragma_extern_prefix);
1339
1340 c_register_pragma_with_expansion (0, "message", handle_pragma_message);
1341
1342 #ifdef REGISTER_TARGET_PRAGMAS
1343 REGISTER_TARGET_PRAGMAS ();
1344 #endif
1345 }
1346
1347 #include "gt-c-pragma.h"