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, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, 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) \
  41   do { warning (OPT_Wpragmas, gmsgid); return; } while (0)
  42 #define GCC_BAD2(gmsgid, arg) \
  43   do { warning (OPT_Wpragmas, gmsgid, arg); return; } while (0)
  44
  45 typedef struct align_stack GTY(())
  46 {
  47   int                  alignment;
  48   tree                 id;
  49   struct align_stack * prev;
  50 } align_stack;
  51
  52 static GTY(()) struct align_stack * alignment_stack;
  53
  54 #ifdef HANDLE_PRAGMA_PACK
  55 static void handle_pragma_pack (cpp_reader *);
  56
  57 #ifdef HANDLE_PRAGMA_PACK_PUSH_POP
  58 /* If we have a "global" #pragma pack(<n>) in effect when the first
  59    #pragma pack(push,<n>) is encountered, this stores the value of
  60    maximum_field_alignment in effect.  When the final pop_alignment()
  61    happens, we restore the value to this, not to a value of 0 for
  62    maximum_field_alignment.  Value is in bits.  */
  63 static int default_alignment;
  64 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = *(alignment_stack == NULL \
  65         ? &default_alignment \
  66         : &alignment_stack->alignment) = (ALIGN))
  67
  68 static void push_alignment (int, tree);
  69 static void pop_alignment (tree);
  70
  71 /* Push an alignment value onto the stack.  */
  72 static void
  73 push_alignment (int alignment, tree id)
  74 {
  75   align_stack * entry;
  76
  77   entry = ggc_alloc (sizeof (* entry));
  78
  79   entry->alignment  = alignment;
  80   entry->id         = id;
  81   entry->prev       = alignment_stack;
  82
  83   /* The current value of maximum_field_alignment is not necessarily
  84      0 since there may be a #pragma pack(<n>) in effect; remember it
  85      so that we can restore it after the final #pragma pop().  */
  86   if (alignment_stack == NULL)
  87     default_alignment = maximum_field_alignment;
  88
  89   alignment_stack = entry;
  90
  91   maximum_field_alignment = alignment;
  92 }
  93
  94 /* Undo a push of an alignment onto the stack.  */
  95 static void
  96 pop_alignment (tree id)
  97 {
  98   align_stack * entry;
  99
 100   if (alignment_stack == NULL)
 101     GCC_BAD ("#pragma pack (pop) encountered without matching #pragma pack (push)");
 102
 103   /* If we got an identifier, strip away everything above the target
 104      entry so that the next step will restore the state just below it.  */
 105   if (id)
 106     {
 107       for (entry = alignment_stack; entry; entry = entry->prev)
 108         if (entry->id == id)
 109           {
 110             alignment_stack = entry;
 111             break;
 112           }
 113       if (entry == NULL)
 114         warning (OPT_Wpragmas, "\
 115 #pragma pack(pop, %s) encountered without matching #pragma pack(push, %s)"
 116                  , IDENTIFIER_POINTER (id), IDENTIFIER_POINTER (id));
 117     }
 118
 119   entry = alignment_stack->prev;
 120
 121   maximum_field_alignment = entry ? entry->alignment : default_alignment;
 122
 123   alignment_stack = entry;
 124 }
 125 #else  /* not HANDLE_PRAGMA_PACK_PUSH_POP */
 126 #define SET_GLOBAL_ALIGNMENT(ALIGN) (maximum_field_alignment = (ALIGN))
 127 #define push_alignment(ID, N) \
 128     GCC_BAD ("#pragma pack(push[, id], <n>) is not supported on this target")
 129 #define pop_alignment(ID) \
 130     GCC_BAD ("#pragma pack(pop[, id], <n>) is not supported on this target")
 131 #endif /* HANDLE_PRAGMA_PACK_PUSH_POP */
 132
 133 /* #pragma pack ()
 134    #pragma pack (N)
 135
 136    #pragma pack (push)
 137    #pragma pack (push, N)
 138    #pragma pack (push, ID)
 139    #pragma pack (push, ID, N)
 140    #pragma pack (pop)
 141    #pragma pack (pop, ID) */
 142 static void
 143 handle_pragma_pack (cpp_reader * ARG_UNUSED (dummy))
 144 {
 145   tree x, id = 0;
 146   int align = -1;
 147   enum cpp_ttype token;
 148   enum { set, push, pop } action;
 149
 150   if (c_lex (&x) != CPP_OPEN_PAREN)
 151     GCC_BAD ("missing %<(%> after %<#pragma pack%> - ignored");
 152
 153   token = c_lex (&x);
 154   if (token == CPP_CLOSE_PAREN)
 155     {
 156       action = set;
 157       align = initial_max_fld_align;
 158     }
 159   else if (token == CPP_NUMBER)
 160     {
 161       align = TREE_INT_CST_LOW (x);
 162       action = set;
 163       if (c_lex (&x) != CPP_CLOSE_PAREN)
 164         GCC_BAD ("malformed %<#pragma pack%> - ignored");
 165     }
 166   else if (token == CPP_NAME)
 167     {
 168 #define GCC_BAD_ACTION do { if (action != pop) \
 169           GCC_BAD ("malformed %<#pragma pack(push[, id][, <n>])%> - ignored"); \
 170         else \
 171           GCC_BAD ("malformed %<#pragma pack(pop[, id])%> - ignored"); \
 172         } while (0)
 173
 174       const char *op = IDENTIFIER_POINTER (x);
 175       if (!strcmp (op, "push"))
 176         action = push;
 177       else if (!strcmp (op, "pop"))
 178         action = pop;
 179       else
 180         GCC_BAD2 ("unknown action %qs for %<#pragma pack%> - ignored", op);
 181
 182       while ((token = c_lex (&x)) == CPP_COMMA)
 183         {
 184           token = c_lex (&x);
 185           if (token == CPP_NAME && id == 0)
 186             {
 187               id = x;
 188             }
 189           else if (token == CPP_NUMBER && action == push && align == -1)
 190             {
 191               align = TREE_INT_CST_LOW (x);
 192               if (align == -1)
 193                 action = set;
 194             }
 195           else
 196             GCC_BAD_ACTION;
 197         }
 198
 199       if (token != CPP_CLOSE_PAREN)
 200         GCC_BAD_ACTION;
 201 #undef GCC_BAD_ACTION
 202     }
 203   else
 204     GCC_BAD ("malformed %<#pragma pack%> - ignored");
 205
 206   if (c_lex (&x) != CPP_EOF)
 207     warning (OPT_Wpragmas, "junk at end of %<#pragma pack%>");
 208
 209   if (flag_pack_struct)
 210     GCC_BAD ("#pragma pack has no effect with -fpack-struct - ignored");
 211
 212   if (action != pop)
 213     switch (align)
 214       {
 215       case 0:
 216       case 1:
 217       case 2:
 218       case 4:
 219       case 8:
 220       case 16:
 221         align *= BITS_PER_UNIT;
 222         break;
 223       case -1:
 224         if (action == push)
 225           {
 226             align = maximum_field_alignment;
 227             break;
 228           }
 229       default:
 230         GCC_BAD2 ("alignment must be a small power of two, not %d", align);
 231       }
 232
 233   switch (action)
 234     {
 235     case set:   SET_GLOBAL_ALIGNMENT (align);  break;
 236     case push:  push_alignment (align, id);    break;
 237     case pop:   pop_alignment (id);            break;
 238     }
 239 }
 240 #endif  /* HANDLE_PRAGMA_PACK */
 241
 242 static GTY(()) tree pending_weaks;
 243
 244 #ifdef HANDLE_PRAGMA_WEAK
 245 static void apply_pragma_weak (tree, tree);
 246 static void handle_pragma_weak (cpp_reader *);
 247
 248 static void
 249 apply_pragma_weak (tree decl, tree value)
 250 {
 251   if (value)
 252     {
 253       value = build_string (IDENTIFIER_LENGTH (value),
 254                             IDENTIFIER_POINTER (value));
 255       decl_attributes (&decl, build_tree_list (get_identifier ("alias"),
 256                                                build_tree_list (NULL, value)),
 257                        0);
 258     }
 259
 260   if (SUPPORTS_WEAK && DECL_EXTERNAL (decl) && TREE_USED (decl)
 261       && !DECL_WEAK (decl) /* Don't complain about a redundant #pragma.  */
 262       && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
 263     warning (OPT_Wpragmas, "applying #pragma weak %q+D after first use "
 264              "results in unspecified behavior", decl);
 265
 266   declare_weak (decl);
 267 }
 268
 269 void
 270 maybe_apply_pragma_weak (tree decl)
 271 {
 272   tree *p, t, id;
 273
 274   /* Avoid asking for DECL_ASSEMBLER_NAME when it's not needed.  */
 275
 276   /* No weak symbols pending, take the short-cut.  */
 277   if (!pending_weaks)
 278     return;
 279   /* If it's not visible outside this file, it doesn't matter whether
 280      it's weak.  */
 281   if (!DECL_EXTERNAL (decl) && !TREE_PUBLIC (decl))
 282     return;
 283   /* If it's not a function or a variable, it can't be weak.
 284      FIXME: what kinds of things are visible outside this file but
 285      aren't functions or variables?   Should this be an assert instead?  */
 286   if (TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
 287     return;
 288
 289   id = DECL_ASSEMBLER_NAME (decl);
 290
 291   for (p = &pending_weaks; (t = *p) ; p = &TREE_CHAIN (t))
 292     if (id == TREE_PURPOSE (t))
 293       {
 294         apply_pragma_weak (decl, TREE_VALUE (t));
 295         *p = TREE_CHAIN (t);
 296         break;
 297       }
 298 }
 299
 300 /* Process all "#pragma weak A = B" directives where we have not seen
 301    a decl for A.  */
 302 void
 303 maybe_apply_pending_pragma_weaks (void)
 304 {
 305   tree *p, t, alias_id, id, decl, *next;
 306
 307   for (p = &pending_weaks; (t = *p) ; p = next)
 308     {
 309       next = &TREE_CHAIN (t);
 310       alias_id = TREE_PURPOSE (t);
 311       id = TREE_VALUE (t);
 312
 313       if (TREE_VALUE (t) == NULL)
 314         continue;
 315
 316       decl = build_decl (FUNCTION_DECL, alias_id, default_function_type);
 317
 318       DECL_ARTIFICIAL (decl) = 1;
 319       TREE_PUBLIC (decl) = 1;
 320       DECL_EXTERNAL (decl) = 1;
 321       DECL_WEAK (decl) = 1;
 322
 323       assemble_alias (decl, id);
 324     }
 325 }
 326
 327 /* #pragma weak name [= value] */
 328 static void
 329 handle_pragma_weak (cpp_reader * ARG_UNUSED (dummy))
 330 {
 331   tree name, value, x, decl;
 332   enum cpp_ttype t;
 333
 334   value = 0;
 335
 336   if (c_lex (&name) != CPP_NAME)
 337     GCC_BAD ("malformed #pragma weak, ignored");
 338   t = c_lex (&x);
 339   if (t == CPP_EQ)
 340     {
 341       if (c_lex (&value) != CPP_NAME)
 342         GCC_BAD ("malformed #pragma weak, ignored");
 343       t = c_lex (&x);
 344     }
 345   if (t != CPP_EOF)
 346     warning (OPT_Wpragmas, "junk at end of #pragma weak");
 347
 348   decl = identifier_global_value (name);
 349   if (decl && DECL_P (decl))
 350     {
 351       apply_pragma_weak (decl, value);
 352       if (value)
 353         assemble_alias (decl, value);
 354     }
 355   else
 356     pending_weaks = tree_cons (name, value, pending_weaks);
 357 }
 358 #else
 359 void
 360 maybe_apply_pragma_weak (tree ARG_UNUSED (decl))
 361 {
 362 }
 363
 364 void
 365 maybe_apply_pending_pragma_weaks (void)
 366 {
 367 }
 368 #endif /* HANDLE_PRAGMA_WEAK */
 369
 370 /* GCC supports two #pragma directives for renaming the external
 371    symbol associated with a declaration (DECL_ASSEMBLER_NAME), for
 372    compatibility with the Solaris and Tru64 system headers.  GCC also
 373    has its own notation for this, __asm__("name") annotations.
 374
 375    Corner cases of these features and their interaction:
 376
 377    1) Both pragmas silently apply only to declarations with external
 378       linkage (that is, TREE_PUBLIC || DECL_EXTERNAL).  Asm labels
 379       do not have this restriction.
 380
 381    2) In C++, both #pragmas silently apply only to extern "C" declarations.
 382       Asm labels do not have this restriction.
 383
 384    3) If any of the three ways of changing DECL_ASSEMBLER_NAME is
 385       applied to a decl whose DECL_ASSEMBLER_NAME is already set, and the
 386       new name is different, a warning issues and the name does not change.
 387
 388    4) The "source name" for #pragma redefine_extname is the DECL_NAME,
 389       *not* the DECL_ASSEMBLER_NAME.
 390
 391    5) If #pragma extern_prefix is in effect and a declaration occurs
 392       with an __asm__ name, the #pragma extern_prefix is silently
 393       ignored for that declaration.
 394
 395    6) If #pragma extern_prefix and #pragma redefine_extname apply to
 396       the same declaration, whichever triggered first wins, and a warning
 397       is issued.  (We would like to have #pragma redefine_extname always
 398       win, but it can appear either before or after the declaration, and
 399       if it appears afterward, we have no way of knowing whether a modified
 400       DECL_ASSEMBLER_NAME is due to #pragma extern_prefix.)  */
 401
 402 static GTY(()) tree pending_redefine_extname;
 403
 404 static void handle_pragma_redefine_extname (cpp_reader *);
 405
 406 /* #pragma redefine_extname oldname newname */
 407 static void
 408 handle_pragma_redefine_extname (cpp_reader * ARG_UNUSED (dummy))
 409 {
 410   tree oldname, newname, decl, x;
 411   enum cpp_ttype t;
 412
 413   if (c_lex (&oldname) != CPP_NAME)
 414     GCC_BAD ("malformed #pragma redefine_extname, ignored");
 415   if (c_lex (&newname) != CPP_NAME)
 416     GCC_BAD ("malformed #pragma redefine_extname, ignored");
 417   t = c_lex (&x);
 418   if (t != CPP_EOF)
 419     warning (OPT_Wpragmas, "junk at end of #pragma redefine_extname");
 420
 421   if (!flag_mudflap && !targetm.handle_pragma_redefine_extname)
 422     {
 423       if (warn_unknown_pragmas > in_system_header)
 424         warning (OPT_Wunknown_pragmas,
 425                  "#pragma redefine_extname not supported on this target");
 426       return;
 427     }
 428
 429   decl = identifier_global_value (oldname);
 430   if (decl
 431       && (TREE_PUBLIC (decl) || DECL_EXTERNAL (decl))
 432       && (TREE_CODE (decl) == FUNCTION_DECL
 433           || TREE_CODE (decl) == VAR_DECL)
 434       && has_c_linkage (decl))
 435     {
 436       if (DECL_ASSEMBLER_NAME_SET_P (decl))
 437         {
 438           const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 439           name = targetm.strip_name_encoding (name);
 440
 441           if (strcmp (name, IDENTIFIER_POINTER (newname)))
 442             warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
 443                      "conflict with previous rename");
 444         }
 445       else
 446         change_decl_assembler_name (decl, newname);
 447     }
 448   else
 449     /* We have to add this to the rename list even if there's already
 450        a global value that doesn't meet the above criteria, because in
 451        C++ "struct foo {...};" puts "foo" in the current namespace but
 452        does *not* conflict with a subsequent declaration of a function
 453        or variable foo.  See g++.dg/other/pragma-re-2.C.  */
 454     add_to_renaming_pragma_list (oldname, newname);
 455 }
 456
 457 /* This is called from here and from ia64.c.  */
 458 void
 459 add_to_renaming_pragma_list (tree oldname, tree newname)
 460 {
 461   tree previous = purpose_member (oldname, pending_redefine_extname);
 462   if (previous)
 463     {
 464       if (TREE_VALUE (previous) != newname)
 465         warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
 466                  "conflict with previous #pragma redefine_extname");
 467       return;
 468     }
 469
 470   pending_redefine_extname
 471     = tree_cons (oldname, newname, pending_redefine_extname);
 472 }
 473
 474 static GTY(()) tree pragma_extern_prefix;
 475
 476 /* #pragma extern_prefix "prefix" */
 477 static void
 478 handle_pragma_extern_prefix (cpp_reader * ARG_UNUSED (dummy))
 479 {
 480   tree prefix, x;
 481   enum cpp_ttype t;
 482
 483   if (c_lex (&prefix) != CPP_STRING)
 484     GCC_BAD ("malformed #pragma extern_prefix, ignored");
 485   t = c_lex (&x);
 486   if (t != CPP_EOF)
 487     warning (OPT_Wpragmas, "junk at end of #pragma extern_prefix");
 488
 489   if (targetm.handle_pragma_extern_prefix)
 490     /* Note that the length includes the null terminator.  */
 491     pragma_extern_prefix = (TREE_STRING_LENGTH (prefix) > 1 ? prefix : NULL);
 492   else if (warn_unknown_pragmas > in_system_header)
 493     warning (OPT_Wunknown_pragmas,
 494              "#pragma extern_prefix not supported on this target");
 495 }
 496
 497 /* Hook from the front ends to apply the results of one of the preceding
 498    pragmas that rename variables.  */
 499
 500 tree
 501 maybe_apply_renaming_pragma (tree decl, tree asmname)
 502 {
 503   tree *p, t;
 504
 505   /* The renaming pragmas are only applied to declarations with
 506      external linkage.  */
 507   if ((TREE_CODE (decl) != FUNCTION_DECL && TREE_CODE (decl) != VAR_DECL)
 508       || (!TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl))
 509       || !has_c_linkage (decl))
 510     return asmname;
 511
 512   /* If the DECL_ASSEMBLER_NAME is already set, it does not change,
 513      but we may warn about a rename that conflicts.  */
 514   if (DECL_ASSEMBLER_NAME_SET_P (decl))
 515     {
 516       const char *oldname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 517       oldname = targetm.strip_name_encoding (oldname);
 518
 519       if (asmname && strcmp (TREE_STRING_POINTER (asmname), oldname))
 520           warning (OPT_Wpragmas, "asm declaration ignored due to "
 521                    "conflict with previous rename");
 522
 523       /* Take any pending redefine_extname off the list.  */
 524       for (p = &pending_redefine_extname; (t = *p); p = &TREE_CHAIN (t))
 525         if (DECL_NAME (decl) == TREE_PURPOSE (t))
 526           {
 527             /* Only warn if there is a conflict.  */
 528             if (strcmp (IDENTIFIER_POINTER (TREE_VALUE (t)), oldname))
 529               warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
 530                        "conflict with previous rename");
 531
 532             *p = TREE_CHAIN (t);
 533             break;
 534           }
 535       return 0;
 536     }
 537
 538   /* Find out if we have a pending #pragma redefine_extname.  */
 539   for (p = &pending_redefine_extname; (t = *p); p = &TREE_CHAIN (t))
 540     if (DECL_NAME (decl) == TREE_PURPOSE (t))
 541       {
 542         tree newname = TREE_VALUE (t);
 543         *p = TREE_CHAIN (t);
 544
 545         /* If we already have an asmname, #pragma redefine_extname is
 546            ignored (with a warning if it conflicts).  */
 547         if (asmname)
 548           {
 549             if (strcmp (TREE_STRING_POINTER (asmname),
 550                         IDENTIFIER_POINTER (newname)) != 0)
 551               warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
 552                        "conflict with __asm__ declaration");
 553             return asmname;
 554           }
 555
 556         /* Otherwise we use what we've got; #pragma extern_prefix is
 557            silently ignored.  */
 558         return build_string (IDENTIFIER_LENGTH (newname),
 559                              IDENTIFIER_POINTER (newname));
 560       }
 561
 562   /* If we've got an asmname, #pragma extern_prefix is silently ignored.  */
 563   if (asmname)
 564     return asmname;
 565
 566   /* If #pragma extern_prefix is in effect, apply it.  */
 567   if (pragma_extern_prefix)
 568     {
 569       const char *prefix = TREE_STRING_POINTER (pragma_extern_prefix);
 570       size_t plen = TREE_STRING_LENGTH (pragma_extern_prefix) - 1;
 571
 572       const char *id = IDENTIFIER_POINTER (DECL_NAME (decl));
 573       size_t ilen = IDENTIFIER_LENGTH (DECL_NAME (decl));
 574
 575       char *newname = (char *) alloca (plen + ilen + 1);
 576
 577       memcpy (newname,        prefix, plen);
 578       memcpy (newname + plen, id, ilen + 1);
 579
 580       return build_string (plen + ilen, newname);
 581     }
 582
 583   /* Nada.  */
 584   return 0;
 585 }
 586
 587
 588 #ifdef HANDLE_PRAGMA_VISIBILITY
 589 static void handle_pragma_visibility (cpp_reader *);
 590
 591 typedef enum symbol_visibility visibility;
 592 DEF_VEC_I (visibility);
 593 DEF_VEC_ALLOC_I (visibility, heap);
 594
 595 /* Sets the default visibility for symbols to something other than that
 596    specified on the command line.  */
 597 static void
 598 handle_pragma_visibility (cpp_reader *dummy ATTRIBUTE_UNUSED)
 599 {
 600   /* Form is #pragma GCC visibility push(hidden)|pop */
 601   tree x;
 602   enum cpp_ttype token;
 603   enum { bad, push, pop } action = bad;
 604   static VEC (visibility, heap) *visstack;
 605
 606   token = c_lex (&x);
 607   if (token == CPP_NAME)
 608     {
 609       const char *op = IDENTIFIER_POINTER (x);
 610       if (!strcmp (op, "push"))
 611         action = push;
 612       else if (!strcmp (op, "pop"))
 613         action = pop;
 614     }
 615   if (bad == action)
 616     GCC_BAD ("#pragma GCC visibility must be followed by push or pop");
 617   else
 618     {
 619       if (pop == action)
 620         {
 621           if (!VEC_length (visibility, visstack))
 622             {
 623               GCC_BAD ("no matching push for %<#pragma GCC visibility pop%>");
 624             }
 625           else
 626             {
 627               default_visibility = VEC_pop (visibility, visstack);
 628               visibility_options.inpragma
 629                 = VEC_length (visibility, visstack) != 0;
 630             }
 631         }
 632       else
 633         {
 634           if (c_lex (&x) != CPP_OPEN_PAREN)
 635             GCC_BAD ("missing %<(%> after %<#pragma GCC visibility push%> - ignored");
 636           token = c_lex (&x);
 637           if (token != CPP_NAME)
 638             {
 639               GCC_BAD ("malformed #pragma GCC visibility push");
 640             }
 641           else
 642             {
 643               const char *str = IDENTIFIER_POINTER (x);
 644               VEC_safe_push (visibility, heap, visstack,
 645                              default_visibility);
 646               if (!strcmp (str, "default"))
 647                 default_visibility = VISIBILITY_DEFAULT;
 648               else if (!strcmp (str, "internal"))
 649                 default_visibility = VISIBILITY_INTERNAL;
 650               else if (!strcmp (str, "hidden"))
 651                 default_visibility = VISIBILITY_HIDDEN;
 652               else if (!strcmp (str, "protected"))
 653                 default_visibility = VISIBILITY_PROTECTED;
 654               else
 655                 {
 656                   GCC_BAD ("#pragma GCC visibility push() must specify default, internal, hidden or protected");
 657                 }
 658               visibility_options.inpragma = 1;
 659             }
 660           if (c_lex (&x) != CPP_CLOSE_PAREN)
 661             GCC_BAD ("missing %<(%> after %<#pragma GCC visibility push%> - ignored");
 662         }
 663     }
 664   if (c_lex (&x) != CPP_EOF)
 665     warning (OPT_Wpragmas, "junk at end of %<#pragma GCC visibility%>");
 666 }
 667
 668 #endif
 669
 670 /* Front-end wrappers for pragma registration to avoid dragging
 671    cpplib.h in almost everywhere.  */
 672 void
 673 c_register_pragma (const char *space, const char *name,
 674                    void (*handler) (struct cpp_reader *))
 675 {
 676   cpp_register_pragma (parse_in, space, name, handler, 0);
 677 }
 678
 679 void
 680 c_register_pragma_with_expansion (const char *space, const char *name,
 681                                   void (*handler) (struct cpp_reader *))
 682 {
 683   cpp_register_pragma (parse_in, space, name, handler, 1);
 684 }
 685
 686 /* Set up front-end pragmas.  */
 687 void
 688 init_pragma (void)
 689 {
 690 #ifdef HANDLE_PRAGMA_PACK
 691 #ifdef HANDLE_PRAGMA_PACK_WITH_EXPANSION
 692   c_register_pragma_with_expansion (0, "pack", handle_pragma_pack);
 693 #else
 694   c_register_pragma (0, "pack", handle_pragma_pack);
 695 #endif
 696 #endif
 697 #ifdef HANDLE_PRAGMA_WEAK
 698   c_register_pragma (0, "weak", handle_pragma_weak);
 699 #endif
 700 #ifdef HANDLE_PRAGMA_VISIBILITY
 701   c_register_pragma ("GCC", "visibility", handle_pragma_visibility);
 702 #endif
 703
 704   c_register_pragma (0, "redefine_extname", handle_pragma_redefine_extname);
 705   c_register_pragma (0, "extern_prefix", handle_pragma_extern_prefix);
 706
 707   c_register_pragma ("GCC", "pch_preprocess", c_common_pch_pragma);
 708
 709 #ifdef REGISTER_TARGET_PRAGMAS
 710   REGISTER_TARGET_PRAGMAS ();
 711 #endif
 712 }
 713
 714 #include "gt-c-pragma.h"