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