gcc/c-pragma.c

   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    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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "rtl.h"
  27 #include "tree.h"
  28 #include "function.h"
  29 #include "cpplib.h"
  30 #include "c-pragma.h"
  31 #include "flags.h"
  32 #include "toplev.h"
  33 #include "ggc.h"
  34 #include "c-common.h"
  35 #include "output.h"
  36 #include "tm_p.h"
  37 #include "vec.h"
  38 #include "target.h"
  39
  40 #define GCC_BAD(gmsgid) do { warning (0, gmsgid); return; } while (0)
  41 #define GCC_BAD2(gmsgid, arg) \
  42   do { warning (0, gmsgid, arg); return; } while (0)
  43
  44 typedef struct align_stack GTY(())
  45 {
  46   int                  alignment;
  47   tree                 id;
  48   struct align_stack * prev;
  49 } align_stack;
  50
  51 static GTY(()) struct align_stack * alignment_stack;
  52
  53 #ifdef HANDLE_PRAGMA_PACK
  54 static void handle_pragma_pack (cpp_reader *);
  55
  56 #ifdef HANDLE_PRAGMA_PACK_PUSH_POP
  57 /* If we have a "global" #pragma pack(<n>) in effect when the first
  58    #pragma pack(push,<n>) is encountered, this stores the value of
  59    maximum_field_alignment in effect.  When the final pop_alignment()
  60    happens, we restore the value to this, not to a value of 0 for
  61    maximum_field_alignment.  Value is in bits.  */
  62 static int default_alignment;
  63 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = *(alignment_stack == NULL \
  64         ? &default_alignment \
  65         : &alignment_stack->alignment) = (ALIGN))
  66
  67 static void push_alignment (int, tree);
  68 static void pop_alignment (tree);
  69
  70 /* Push an alignment value onto the stack.  */
  71 static void
  72 push_alignment (int alignment, tree id)
  73 {
  74   align_stack * entry;
  75
  76   entry = ggc_alloc (sizeof (* entry));
  77
  78   entry->alignment  = alignment;
  79   entry->id         = id;
  80   entry->prev       = alignment_stack;
  81
  82   /* The current value of maximum_field_alignment is not necessarily
  83      0 since there may be a #pragma pack(<n>) in effect; remember it
  84      so that we can restore it after the final #pragma pop().  */
  85   if (alignment_stack == NULL)
  86     default_alignment = maximum_field_alignment;
  87
  88   alignment_stack = entry;
  89
  90   maximum_field_alignment = alignment;
  91 }
  92
  93 /* Undo a push of an alignment onto the stack.  */
  94 static void
  95 pop_alignment (tree id)
  96 {
  97   align_stack * entry;
  98
  99   if (alignment_stack == NULL)
 100     GCC_BAD ("#pragma pack (pop) encountered without matching #pragma pack (push)");
 101
 102   /* If we got an identifier, strip away everything above the target
 103      entry so that the next step will restore the state just below it.  */
 104   if (id)
 105     {
 106       for (entry = alignment_stack; entry; entry = entry->prev)
 107         if (entry->id == id)
 108           {
 109             alignment_stack = entry;
 110             break;
 111           }
 112       if (entry == NULL)
 113         warning (0, "\
 114 #pragma pack(pop, %s) encountered without matching #pragma pack(push, %s)"
 115                  , IDENTIFIER_POINTER (id), IDENTIFIER_POINTER (id));
 116     }
 117
 118   entry = alignment_stack->prev;
 119
 120   maximum_field_alignment = entry ? entry->alignment : default_alignment;
 121
 122   alignment_stack = entry;
 123 }
 124 #else  /* not HANDLE_PRAGMA_PACK_PUSH_POP */
 125 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = (ALIGN))
 126 #define push_alignment(ID, N) \
 127     GCC_BAD ("#pragma pack(push[, id], <n>) is not supported on this target")
 128 #define pop_alignment(ID) \
 129     GCC_BAD ("#pragma pack(pop[, id], <n>) is not supported on this target")
 130 #endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
 131
 132 /* #pragma pack ()
 133    #pragma pack (N)
 134
 135    #pragma pack (push)
 136    #pragma pack (push, N)
 137    #pragma pack (push, ID)
 138    #pragma pack (push, ID, N)
 139    #pragma pack (pop)
 140    #pragma pack (pop, ID) */
 141 static void
 142 handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy))
 143 {
 144   tree x, id = 0;
 145   int align = -1;
 146   enum cpp_ttype token;
 147   enum { set, push, pop } action;
 148
 149   if (c_lex (&x) != CPP_OPEN_PAREN)
 150     GCC_BAD ("missing %<(%> after %<#pragma pack%> - ignored");
 151
 152   token = c_lex (&x);
 153   if (token == CPP_CLOSE_PAREN)
 154     {
 155       action = set;
 156       align = initial_max_fld_align;
 157     }
 158   else if (token == CPP_NUMBER)
 159     {
 160       align = TREE_INT_CST_LOW (x);
 161       action = set;
 162       if (c_lex (&x) != CPP_CLOSE_PAREN)
 163         GCC_BAD ("malformed %<#pragma pack%> - ignored");
 164     }
 165   else if (token == CPP_NAME)
 166     {
 167 #define GCC_BAD_ACTION do { if (action != pop) \
 168           GCC_BAD ("malformed %<#pragma pack(push[, id][, <n>])%> - ignored"); \
 169         else \
 170           GCC_BAD ("malformed %<#pragma pack(pop[, id])%> - ignored"); \
 171         } while (0)
 172
 173       const char *op = IDENTIFIER_POINTER (x);
 174       if (!strcmp (op, "push"))
 175         action = push;
 176       else if (!strcmp (op, "pop"))
 177         action = pop;
 178       else
 179         GCC_BAD2 ("unknown action %qs for %<#pragma pack%> - ignored", op);
 180
 181       while ((token = c_lex (&x)) == CPP_COMMA)
 182         {
 183           token = c_lex (&x);
 184           if (token == CPP_NAME && id == 0)
 185             {
 186               id = x;
 187             }
 188           else if (token == CPP_NUMBER && action == push && align == -1)
 189             {
 190               align = TREE_INT_CST_LOW (x);
 191               if (align == -1)
 192                 action = set;
 193             }
 194           else
 195             GCC_BAD_ACTION;
 196         }
 197
 198       if (token != CPP_CLOSE_PAREN)
 199         GCC_BAD_ACTION;
 200 #undef GCC_BAD_ACTION
 201     }
 202   else
 203     GCC_BAD ("malformed %<#pragma pack%> - ignored");
 204
 205   if (c_lex (&x) != CPP_EOF)
 206     warning (0, "junk at end of %<#pragma pack%>");
 207
 208   if (flag_pack_struct)
 209     GCC_BAD ("#pragma pack has no effect with -fpack-struct - ignored");
 210
 211   if (action != pop)
 212     switch (align)
 213       {
 214       case 0:
 215       case 1:
 216       case 2:
 217       case 4:
 218       case 8:
 219       case 16:
 220         align *= BITS_PER_UNIT;
 221         break;
 222       case -1:
 223         if (action == push)
 224           {
 225             align = maximum_field_alignment;
 226             break;
 227           }
 228       default:
 229         GCC_BAD2 ("alignment must be a small power of two, not %d", align);
 230       }
 231
 232   switch (action)
 233     {
 234     case set:   SET_GLOBAL_ALIGNMENT (align);  break;
 235     case push:  push_alignment (align, id);    break;
 236     case pop:   pop_alignment (id);            break;
 237     }
 238 }
 239 #endif  /* HANDLE_PRAGMA_PACK */
 240
 241 static GTY(()) tree pending_weaks;
 242
 243 #ifdef HANDLE_PRAGMA_WEAK
 244 static void apply_pragma_weak (tree, tree);
 245 static void handle_pragma_weak (cpp_reader *);
 246
 247 static void
 248 apply_pragma_weak (tree decl, tree value)
 249 {
 250   if (value)
 251     {
 252       value = build_string (IDENTIFIER_LENGTH (value),
 253                             IDENTIFIER_POINTER (value));
 254       decl_attributes (&decl, build_tree_list (get_identifier ("alias"),
 255                                                build_tree_list (NULL, value)),
 256                        0);
 257     }
 258
 259   if (SUPPORTS_WEAK && DECL_EXTERNAL (decl) && TREE_USED (decl)
 260       && !DECL_WEAK (decl) /* Don't complain about a redundant #pragma.  */
 261       && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
 262     warning (0, "%Japplying #pragma weak %qD after first use results "
 263              "in unspecified behavior", decl, decl);
 264
 265   declare_weak (decl);
 266 }
 267
 268 void
 269 maybe_apply_pragma_weak (tree decl)
 270 {
 271   tree *p, t, id;
 272
 273   /* Avoid asking for DECL_ASSEMBLER_NAME when it's not needed.  */
 274
 275   /* No weak symbols pending, take the short-cut.  */
 276   if (!pending_weaks)
 277     return;
 278   /* If it's not visible outside this file, it doesn't matter whether
 279      it's weak.  */
 280   if (!DECL_EXTERNAL (decl) && !TREE_PUBLIC (decl))
 281     return;
 282   /* If it's not a function or a variable, it can't be weak.
 283      FIXME: what kinds of things are visible outside this file but
 284      aren't functions or variables?   Should this be an assert instead?  */
 285   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
 286     return;
 287
 288   id = DECL_ASSEMBLER_NAME (decl);
 289
 290   for (p = &pending_weaks; (t = *p) ; p = &TREE_CHAIN (t))
 291     if (id == TREE_PURPOSE (t))
 292       {
 293         apply_pragma_weak (decl, TREE_VALUE (t));
 294         *p = TREE_CHAIN (t);
 295         break;
 296       }
 297 }
 298
 299 /* Process all "#pragma weak A = B" directives where we have not seen
 300    a decl for A.  */
 301 void
 302 maybe_apply_pending_pragma_weaks (void)
 303 {
 304   tree *p, t, alias_id, id, decl, *next;
 305
 306   for (p = &pending_weaks; (t = *p) ; p = next)
 307     {
 308       next = &TREE_CHAIN (t);
 309       alias_id = TREE_PURPOSE (t);
 310       id = TREE_VALUE (t);
 311
 312       if (TREE_VALUE (t) == NULL)
 313         continue;
 314
 315       decl = build_decl (FUNCTION_DECL, alias_id, default_function_type);
 316
 317       DECL_ARTIFICIAL (decl) = 1;
 318       TREE_PUBLIC (decl) = 1;
 319       DECL_EXTERNAL (decl) = 1;
 320       DECL_WEAK (decl) = 1;
 321
 322       assemble_alias (decl, id);
 323     }
 324 }
 325
 326 /* #pragma weak name [= value] */
 327 static void
 328 handle_pragma_weak (cpp_reader * ARG_UNUSED (dummy))
 329 {
 330   tree name, value, x, decl;
 331   enum cpp_ttype t;
 332
 333   value = 0;
 334
 335   if (c_lex (&name) != CPP_NAME)
 336     GCC_BAD ("malformed #pragma weak, ignored");
 337   t = c_lex (&x);
 338   if (t == CPP_EQ)
 339     {
 340       if (c_lex (&value) != CPP_NAME)
 341         GCC_BAD ("malformed #pragma weak, ignored");
 342       t = c_lex (&x);
 343     }
 344   if (t != CPP_EOF)
 345     warning (0, "junk at end of #pragma weak");
 346
 347   decl = identifier_global_value (name);
 348   if (decl && DECL_P (decl))
 349     {
 350       apply_pragma_weak (decl, value);
 351       if (value)
 352         assemble_alias (decl, value);
 353     }
 354   else
 355     pending_weaks = tree_cons (name, value, pending_weaks);
 356 }
 357 #else
 358 void
 359 maybe_apply_pragma_weak (tree ARG_UNUSED (decl))
 360 {
 361 }
 362
 363 void
 364 maybe_apply_pending_pragma_weaks (void)
 365 {
 366 }
 367 #endif /* HANDLE_PRAGMA_WEAK */
 368
 369 /* GCC supports two #pragma directives for renaming the external
 370    symbol associated with a declaration (DECL_ASSEMBLER_NAME), for
 371    compatibility with the Solaris and Tru64 system headers.  GCC also
 372    has its own notation for this, __asm__("name") annotations.
 373
 374    Corner cases of these features and their interaction:
 375
 376    1) Both pragmas silently apply only to declarations with external
 377       linkage (that is, TREE_PUBLIC || DECL_EXTERNAL).  Asm labels
 378       do not have this restriction.
 379
 380    2) In C++, both #pragmas silently apply only to extern "C" declarations.
 381       Asm labels do not have this restriction.
 382
 383    3) If any of the three ways of changing DECL_ASSEMBLER_NAME is
 384       applied to a decl whose DECL_ASSEMBLER_NAME is already set, and the
 385       new name is different, a warning issues and the name does not change.
 386
 387    4) The "source name" for #pragma redefine_extname is the DECL_NAME,
 388       *not* the DECL_ASSEMBLER_NAME.
 389
 390    5) If #pragma extern_prefix is in effect and a declaration occurs
 391       with an __asm__ name, the #pragma extern_prefix is silently
 392       ignored for that declaration.
 393
 394    6) If #pragma extern_prefix and #pragma redefine_extname apply to
 395       the same declaration, whichever triggered first wins, and a warning
 396       is issued.  (We would like to have #pragma redefine_extname always
 397       win, but it can appear either before or after the declaration, and
 398       if it appears afterward, we have no way of knowing whether a modified
 399       DECL_ASSEMBLER_NAME is due to #pragma extern_prefix.)  */
 400
 401 static GTY(()) tree pending_redefine_extname;
 402
 403 static void handle_pragma_redefine_extname (cpp_reader *);
 404
 405 /* #pragma redefine_extname oldname newname */
 406 static void
 407 handle_pragma_redefine_extname (cpp_reader * ARG_UNUSED (dummy))
 408 {
 409   tree oldname, newname, decl, x;
 410   enum cpp_ttype t;
 411
 412   if (c_lex (&oldname) != CPP_NAME)
 413     GCC_BAD ("malformed #pragma redefine_extname, ignored");
 414   if (c_lex (&newname) != CPP_NAME)
 415     GCC_BAD ("malformed #pragma redefine_extname, ignored");
 416   t = c_lex (&x);
 417   if (t != CPP_EOF)
 418     warning (0, "junk at end of #pragma redefine_extname");
 419
 420   if (!flag_mudflap && !targetm.handle_pragma_redefine_extname)
 421     {
 422       if (warn_unknown_pragmas > in_system_header)
 423         warning (OPT_Wunknown_pragmas,
 424                  "#pragma redefine_extname not supported on this target");
 425       return;
 426     }
 427
 428   decl = identifier_global_value (oldname);
 429   if (decl
 430       && (TREE_PUBLIC (decl) || DECL_EXTERNAL (decl))
 431       && (TREE_CODE (decl) == FUNCTION_DECL
 432           || TREE_CODE (decl) == VAR_DECL)
 433       && has_c_linkage (decl))
 434     {
 435       if (DECL_ASSEMBLER_NAME_SET_P (decl))
 436         {
 437           const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 438           name = targetm.strip_name_encoding (name);
 439
 440           if (strcmp (name, IDENTIFIER_POINTER (newname)))
 441             warning (0, "#pragma redefine_extname ignored due to conflict with "
 442                      "previous rename");
 443         }
 444       else
 445         change_decl_assembler_name (decl, newname);
 446     }
 447   else
 448     /* We have to add this to the rename list even if there's already
 449        a global value that doesn't meet the above criteria, because in
 450        C++ "struct foo {...};" puts "foo" in the current namespace but
 451        does *not* conflict with a subsequent declaration of a function
 452        or variable foo.  See g++.dg/other/pragma-re-2.C.  */
 453     add_to_renaming_pragma_list (oldname, newname);
 454 }
 455
 456 /* This is called from here and from ia64.c.  */
 457 void
 458 add_to_renaming_pragma_list (tree oldname, tree newname)
 459 {
 460   tree previous = purpose_member (oldname, pending_redefine_extname);
 461   if (previous)
 462     {
 463       if (TREE_VALUE (previous) != newname)
 464         warning (0, "#pragma redefine_extname ignored due to conflict with "
 465                  "previous #pragma redefine_extname");
 466       return;
 467     }
 468
 469   pending_redefine_extname
 470     = tree_cons (oldname, newname, pending_redefine_extname);
 471 }
 472
 473 static GTY(()) tree pragma_extern_prefix;
 474
 475 /* #pragma extern_prefix "prefix" */
 476 static void
 477 handle_pragma_extern_prefix (cpp_reader * ARG_UNUSED (dummy))
 478 {
 479   tree prefix, x;
 480   enum cpp_ttype t;
 481
 482   if (c_lex (&prefix) != CPP_STRING)
 483     GCC_BAD ("malformed #pragma extern_prefix, ignored");
 484   t = c_lex (&x);
 485   if (t != CPP_EOF)
 486     warning (0, "junk at end of #pragma extern_prefix");
 487
 488   if (targetm.handle_pragma_extern_prefix)
 489     /* Note that the length includes the null terminator.  */
 490     pragma_extern_prefix = (TREE_STRING_LENGTH (prefix) > 1 ? prefix : NULL);
 491   else if (warn_unknown_pragmas > in_system_header)
 492     warning (OPT_Wunknown_pragmas,
 493              "#pragma extern_prefix not supported on this target");
 494 }
 495
 496 /* Hook from the front ends to apply the results of one of the preceding
 497    pragmas that rename variables.  */
 498
 499 tree
 500 maybe_apply_renaming_pragma (tree decl, tree asmname)
 501 {
 502   tree *p, t;
 503
 504   /* The renaming pragmas are only applied to declarations with
 505      external linkage.  */
 506   if ((TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
 507       || (!TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
 508       || !has_c_linkage (decl))
 509     return asmname;
 510
 511   /* If the DECL_ASSEMBLER_NAME is already set, it does not change,
 512      but we may warn about a rename that conflicts.  */
 513   if (DECL_ASSEMBLER_NAME_SET_P (decl))
 514     {
 515       const char *oldname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 516       oldname = targetm.strip_name_encoding (oldname);
 517
 518       if (asmname && strcmp (TREE_STRING_POINTER (asmname), oldname))
 519           warning (0, "asm declaration ignored due to "
 520                    "conflict with previous rename");
 521
 522       /* Take any pending redefine_extname off the list.  */
 523       for (p = &pending_redefine_extname; (t = *p); p = &TREE_CHAIN (t))
 524         if (DECL_NAME (decl) == TREE_PURPOSE (t))
 525           {
 526             /* Only warn if there is a conflict.  */
 527             if (strcmp (IDENTIFIER_POINTER (TREE_VALUE (t)), oldname))
 528               warning (0, "#pragma redefine_extname ignored due to "
 529                        "conflict with previous rename");
 530
 531             *p = TREE_CHAIN (t);
 532             break;
 533           }
 534       return 0;
 535     }
 536
 537   /* Find out if we have a pending #pragma redefine_extname.  */
 538   for (p = &pending_redefine_extname; (t = *p); p = &TREE_CHAIN (t))
 539     if (DECL_NAME (decl) == TREE_PURPOSE (t))
 540       {
 541         tree newname = TREE_VALUE (t);
 542         *p = TREE_CHAIN (t);
 543
 544         /* If we already have an asmname, #pragma redefine_extname is
 545            ignored (with a warning if it conflicts).  */
 546         if (asmname)
 547           {
 548             if (strcmp (TREE_STRING_POINTER (asmname),
 549                         IDENTIFIER_POINTER (newname)) != 0)
 550               warning (0, "#pragma redefine_extname ignored due to "
 551                        "conflict with __asm__ declaration");
 552             return asmname;
 553           }
 554
 555         /* Otherwise we use what we've got; #pragma extern_prefix is
 556            silently ignored.  */
 557         return build_string (IDENTIFIER_LENGTH (newname),
 558                              IDENTIFIER_POINTER (newname));
 559       }
 560
 561   /* If we've got an asmname, #pragma extern_prefix is silently ignored.  */
 562   if (asmname)
 563     return asmname;
 564
 565   /* If #pragma extern_prefix is in effect, apply it.  */
 566   if (pragma_extern_prefix)
 567     {
 568       const char *prefix = TREE_STRING_POINTER (pragma_extern_prefix);
 569       size_t plen = TREE_STRING_LENGTH (pragma_extern_prefix) - 1;
 570
 571       const char *id = IDENTIFIER_POINTER (DECL_NAME (decl));
 572       size_t ilen = IDENTIFIER_LENGTH (DECL_NAME (decl));
 573
 574       char *newname = (char *) alloca (plen + ilen + 1);
 575
 576       memcpy (newname,        prefix, plen);
 577       memcpy (newname + plen, id, ilen + 1);
 578
 579       return build_string (plen + ilen, newname);
 580     }
 581
 582   /* Nada.  */
 583   return 0;
 584 }
 585
 586
 587 #ifdef HANDLE_PRAGMA_VISIBILITY
 588 static void handle_pragma_visibility (cpp_reader *);
 589
 590 typedef enum symbol_visibility visibility;
 591 DEF_VEC_I (visibility);
 592 DEF_VEC_ALLOC_I (visibility, heap);
 593
 594 /* Sets the default visibility for symbols to something other than that
 595    specified on the command line.  */
 596 static void
 597 handle_pragma_visibility (cpp_reader *dummy ATTRIBUTE_UNUSED)
 598 {
 599   /* Form is #pragma GCC visibility push(hidden)|pop */
 600   tree x;
 601   enum cpp_ttype token;
 602   enum { bad, push, pop } action = bad;
 603   static VEC (visibility, heap) *visstack;
 604
 605   token = c_lex (&x);
 606   if (token == CPP_NAME)
 607     {
 608       const char *op = IDENTIFIER_POINTER (x);
 609       if (!strcmp (op, "push"))
 610         action = push;
 611       else if (!strcmp (op, "pop"))
 612         action = pop;
 613     }
 614   if (bad == action)
 615     GCC_BAD ("#pragma GCC visibility must be followed by push or pop");
 616   else
 617     {
 618       if (pop == action)
 619         {
 620           if (!VEC_length (visibility, visstack))
 621             {
 622               GCC_BAD ("No matching push for %<#pragma GCC visibility pop%>");
 623             }
 624           else
 625             {
 626               default_visibility = VEC_pop (visibility, visstack);
 627               visibility_options.inpragma
 628                 = VEC_length (visibility, visstack) != 0;
 629             }
 630         }
 631       else
 632         {
 633           if (c_lex (&x) != CPP_OPEN_PAREN)
 634             GCC_BAD ("missing %<(%> after %<#pragma GCC visibility push%> - ignored");
 635           token = c_lex (&x);
 636           if (token != CPP_NAME)
 637             {
 638               GCC_BAD ("malformed #pragma GCC visibility push");
 639             }
 640           else
 641             {
 642               const char *str = IDENTIFIER_POINTER (x);
 643               VEC_safe_push (visibility, heap, visstack,
 644                              default_visibility);
 645               if (!strcmp (str, "default"))
 646                 default_visibility = VISIBILITY_DEFAULT;
 647               else if (!strcmp (str, "internal"))
 648                 default_visibility = VISIBILITY_INTERNAL;
 649               else if (!strcmp (str, "hidden"))
 650                 default_visibility = VISIBILITY_HIDDEN;
 651               else if (!strcmp (str, "protected"))
 652                 default_visibility = VISIBILITY_PROTECTED;
 653               else
 654                 {
 655                   GCC_BAD ("#pragma GCC visibility push() must specify default, internal, hidden or protected");
 656                 }
 657               visibility_options.inpragma = 1;
 658             }
 659           if (c_lex (&x) != CPP_CLOSE_PAREN)
 660             GCC_BAD ("missing %<(%> after %<#pragma GCC visibility push%> - ignored");
 661         }
 662     }
 663   if (c_lex (&x) != CPP_EOF)
 664     warning (0, "junk at end of %<#pragma GCC visibility%>");
 665 }
 666
 667 #endif
 668
 669 /* Front-end wrappers for pragma registration to avoid dragging
 670    cpplib.h in almost everywhere.  */
 671 void
 672 c_register_pragma (const char *space, const char *name,
 673                    void (*handler) (struct cpp_reader *))
 674 {
 675   cpp_register_pragma (parse_in, space, name, handler, 0);
 676 }
 677
 678 void
 679 c_register_pragma_with_expansion (const char *space, const char *name,
 680                                   void (*handler) (struct cpp_reader *))
 681 {
 682   cpp_register_pragma (parse_in, space, name, handler, 1);
 683 }
 684
 685 /* Set up front-end pragmas.  */
 686 void
 687 init_pragma (void)
 688 {
 689 #ifdef HANDLE_PRAGMA_PACK
 690 #ifdef HANDLE_PRAGMA_PACK_WITH_EXPANSION
 691   c_register_pragma_with_expansion (0, "pack", handle_pragma_pack);
 692 #else
 693   c_register_pragma (0, "pack", handle_pragma_pack);
 694 #endif
 695 #endif
 696 #ifdef HANDLE_PRAGMA_WEAK
 697   c_register_pragma (0, "weak", handle_pragma_weak);
 698 #endif
 699 #ifdef HANDLE_PRAGMA_VISIBILITY
 700   c_register_pragma ("GCC", "visibility", handle_pragma_visibility);
 701 #endif
 702
 703   c_register_pragma (0, "redefine_extname", handle_pragma_redefine_extname);
 704   c_register_pragma (0, "extern_prefix", handle_pragma_extern_prefix);
 705
 706   c_register_pragma ("GCC", "pch_preprocess", c_common_pch_pragma);
 707
 708 #ifdef REGISTER_TARGET_PRAGMAS
 709   REGISTER_TARGET_PRAGMAS ();
 710 #endif
 711 }
 712
 713 #include "gt-c-pragma.h"