gcc/config/darwin-c.c

   1 /* Darwin support needed only by C/C++ frontends.
   2    Copyright (C) 2001-2018 Free Software Foundation, Inc.
   3    Contributed by Apple Computer Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License 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 "target.h"
  25 #include "c-family/c-target.h"
  26 #include "c-family/c-target-def.h"
  27 #include "memmodel.h"
  28 #include "tm_p.h"
  29 #include "cgraph.h"
  30 #include "incpath.h"
  31 #include "c-family/c-pragma.h"
  32 #include "c-family/c-format.h"
  33 #include "cppdefault.h"
  34 #include "prefix.h"
  35 #include "../../libcpp/internal.h"
  36
  37 /* Pragmas.  */
  38
  39 #define BAD(gmsgid) do { warning (OPT_Wpragmas, gmsgid); return; } while (0)
  40 #define BAD2(msgid, arg) do { warning (OPT_Wpragmas, msgid, arg); return; } while (0)
  41
  42 static bool using_frameworks = false;
  43
  44 static const char *find_subframework_header (cpp_reader *pfile, const char *header,
  45                                              cpp_dir **dirp);
  46
  47 typedef struct align_stack
  48 {
  49   int alignment;
  50   struct align_stack * prev;
  51 } align_stack;
  52
  53 static struct align_stack * field_align_stack = NULL;
  54
  55 /* Maintain a small stack of alignments.  This is similar to pragma
  56    pack's stack, but simpler.  */
  57
  58 static void
  59 push_field_alignment (int bit_alignment)
  60 {
  61   align_stack *entry = XNEW (align_stack);
  62
  63   entry->alignment = maximum_field_alignment;
  64   entry->prev = field_align_stack;
  65   field_align_stack = entry;
  66
  67   maximum_field_alignment = bit_alignment;
  68 }
  69
  70 static void
  71 pop_field_alignment (void)
  72 {
  73   if (field_align_stack)
  74     {
  75       align_stack *entry = field_align_stack;
  76
  77       maximum_field_alignment = entry->alignment;
  78       field_align_stack = entry->prev;
  79       free (entry);
  80     }
  81   else
  82     error ("too many #pragma options align=reset");
  83 }
  84
  85 /* Handlers for Darwin-specific pragmas.  */
  86
  87 void
  88 darwin_pragma_ignore (cpp_reader *pfile ATTRIBUTE_UNUSED)
  89 {
  90   /* Do nothing.  */
  91 }
  92
  93 /* #pragma options align={mac68k|power|reset} */
  94
  95 void
  96 darwin_pragma_options (cpp_reader *pfile ATTRIBUTE_UNUSED)
  97 {
  98   const char *arg;
  99   tree t, x;
 100
 101   if (pragma_lex (&t) != CPP_NAME)
 102     BAD ("malformed '#pragma options', ignoring");
 103   arg = IDENTIFIER_POINTER (t);
 104   if (strcmp (arg, "align"))
 105     BAD ("malformed '#pragma options', ignoring");
 106   if (pragma_lex (&t) != CPP_EQ)
 107     BAD ("malformed '#pragma options', ignoring");
 108   if (pragma_lex (&t) != CPP_NAME)
 109     BAD ("malformed '#pragma options', ignoring");
 110
 111   if (pragma_lex (&x) != CPP_EOF)
 112     warning (OPT_Wpragmas, "junk at end of '#pragma options'");
 113
 114   arg = IDENTIFIER_POINTER (t);
 115   if (!strcmp (arg, "mac68k"))
 116     push_field_alignment (16);
 117   else if (!strcmp (arg, "power"))
 118     push_field_alignment (0);
 119   else if (!strcmp (arg, "reset"))
 120     pop_field_alignment ();
 121   else
 122     BAD ("malformed '#pragma options align={mac68k|power|reset}', ignoring");
 123 }
 124
 125 /* #pragma unused ([var {, var}*]) */
 126
 127 void
 128 darwin_pragma_unused (cpp_reader *pfile ATTRIBUTE_UNUSED)
 129 {
 130   tree decl, x;
 131   int tok;
 132
 133   if (pragma_lex (&x) != CPP_OPEN_PAREN)
 134     BAD ("missing '(' after '#pragma unused', ignoring");
 135
 136   while (1)
 137     {
 138       tok = pragma_lex (&decl);
 139       if (tok == CPP_NAME && decl)
 140         {
 141           tree local = lookup_name (decl);
 142           if (local && (TREE_CODE (local) == PARM_DECL
 143                         || TREE_CODE (local) == VAR_DECL))
 144             {
 145               TREE_USED (local) = 1;
 146               DECL_READ_P (local) = 1;
 147             }
 148           tok = pragma_lex (&x);
 149           if (tok != CPP_COMMA)
 150             break;
 151         }
 152     }
 153
 154   if (tok != CPP_CLOSE_PAREN)
 155     BAD ("missing ')' after '#pragma unused', ignoring");
 156
 157   if (pragma_lex (&x) != CPP_EOF)
 158     BAD ("junk at end of '#pragma unused'");
 159 }
 160
 161 /* Parse the ms_struct pragma.  */
 162 void
 163 darwin_pragma_ms_struct (cpp_reader *pfile ATTRIBUTE_UNUSED)
 164 {
 165   const char *arg;
 166   tree t;
 167
 168   if (pragma_lex (&t) != CPP_NAME)
 169     BAD ("malformed '#pragma ms_struct', ignoring");
 170   arg = IDENTIFIER_POINTER (t);
 171
 172   if (!strcmp (arg, "on"))
 173     darwin_ms_struct = true;
 174   else if (!strcmp (arg, "off") || !strcmp (arg, "reset"))
 175     darwin_ms_struct = false;
 176   else
 177     BAD ("malformed '#pragma ms_struct {on|off|reset}', ignoring");
 178
 179   if (pragma_lex (&t) != CPP_EOF)
 180     BAD ("junk at end of '#pragma ms_struct'");
 181 }
 182
 183 static struct frameworks_in_use {
 184   size_t len;
 185   const char *name;
 186   cpp_dir* dir;
 187 } *frameworks_in_use;
 188 static int num_frameworks = 0;
 189 static int max_frameworks = 0;
 190
 191
 192 /* Remember which frameworks have been seen, so that we can ensure
 193    that all uses of that framework come from the same framework.  DIR
 194    is the place where the named framework NAME, which is of length
 195    LEN, was found.  We copy the directory name from NAME, as it will be
 196    freed by others.  */
 197
 198 static void
 199 add_framework (const char *name, size_t len, cpp_dir *dir)
 200 {
 201   char *dir_name;
 202   int i;
 203   for (i = 0; i < num_frameworks; ++i)
 204     {
 205       if (len == frameworks_in_use[i].len
 206           && strncmp (name, frameworks_in_use[i].name, len) == 0)
 207         {
 208           return;
 209         }
 210     }
 211   if (i >= max_frameworks)
 212     {
 213       max_frameworks = i*2;
 214       max_frameworks += i == 0;
 215       frameworks_in_use = XRESIZEVEC (struct frameworks_in_use,
 216                                       frameworks_in_use, max_frameworks);
 217     }
 218   dir_name = XNEWVEC (char, len + 1);
 219   memcpy (dir_name, name, len);
 220   dir_name[len] = '\0';
 221   frameworks_in_use[num_frameworks].name = dir_name;
 222   frameworks_in_use[num_frameworks].len = len;
 223   frameworks_in_use[num_frameworks].dir = dir;
 224   ++num_frameworks;
 225 }
 226
 227 /* Recall if we have seen the named framework NAME, before, and where
 228    we saw it.  NAME is LEN bytes long.  The return value is the place
 229    where it was seen before.  */
 230
 231 static struct cpp_dir*
 232 find_framework (const char *name, size_t len)
 233 {
 234   int i;
 235   for (i = 0; i < num_frameworks; ++i)
 236     {
 237       if (len == frameworks_in_use[i].len
 238           && strncmp (name, frameworks_in_use[i].name, len) == 0)
 239         {
 240           return frameworks_in_use[i].dir;
 241         }
 242     }
 243   return 0;
 244 }
 245
 246 /* There are two directories in a framework that contain header files,
 247    Headers and PrivateHeaders.  We search Headers first as it is more
 248    common to upgrade a header from PrivateHeaders to Headers and when
 249    that is done, the old one might hang around and be out of data,
 250    causing grief.  */
 251
 252 struct framework_header {const char * dirName; int dirNameLen; };
 253 static struct framework_header framework_header_dirs[] = {
 254   { "Headers", 7 },
 255   { "PrivateHeaders", 14 },
 256   { NULL, 0 }
 257 };
 258
 259 /* Returns a pointer to a malloced string that contains the real pathname
 260    to the file, given the base name and the name.  */
 261
 262 static char *
 263 framework_construct_pathname (const char *fname, cpp_dir *dir)
 264 {
 265   const char *buf;
 266   size_t fname_len, frname_len;
 267   cpp_dir *fast_dir;
 268   char *frname;
 269   struct stat st;
 270   int i;
 271
 272   /* Framework names must have a / in them.  */
 273   buf = strchr (fname, '/');
 274   if (buf)
 275     fname_len = buf - fname;
 276   else
 277     return 0;
 278
 279   fast_dir = find_framework (fname, fname_len);
 280
 281   /* Framework includes must all come from one framework.  */
 282   if (fast_dir && dir != fast_dir)
 283     return 0;
 284
 285   frname = XNEWVEC (char, strlen (fname) + dir->len + 2
 286                     + strlen(".framework/") + strlen("PrivateHeaders"));
 287   memcpy (&frname[0], dir->name, dir->len);
 288   frname_len = dir->len;
 289   if (frname_len && frname[frname_len-1] != '/')
 290     frname[frname_len++] = '/';
 291   memcpy (&frname[frname_len], fname, fname_len);
 292   frname_len += fname_len;
 293   memcpy (&frname[frname_len], ".framework/", strlen (".framework/"));
 294   frname_len += strlen (".framework/");
 295
 296   if (fast_dir == 0)
 297     {
 298       frname[frname_len-1] = 0;
 299       if (stat (frname, &st) == 0)
 300         {
 301           /* As soon as we find the first instance of the framework,
 302              we stop and never use any later instance of that
 303              framework.  */
 304           add_framework (fname, fname_len, dir);
 305         }
 306       else
 307         {
 308           /* If we can't find the parent directory, no point looking
 309              further.  */
 310           free (frname);
 311           return 0;
 312         }
 313       frname[frname_len-1] = '/';
 314     }
 315
 316   /* Append framework_header_dirs and header file name */
 317   for (i = 0; framework_header_dirs[i].dirName; i++)
 318     {
 319       memcpy (&frname[frname_len],
 320                framework_header_dirs[i].dirName,
 321                framework_header_dirs[i].dirNameLen);
 322       strcpy (&frname[frname_len + framework_header_dirs[i].dirNameLen],
 323               &fname[fname_len]);
 324
 325       if (stat (frname, &st) == 0)
 326         return frname;
 327     }
 328
 329   free (frname);
 330   return 0;
 331 }
 332
 333 /* Search for FNAME in sub-frameworks.  pname is the context that we
 334    wish to search in.  Return the path the file was found at,
 335    otherwise return 0.  */
 336
 337 static const char*
 338 find_subframework_file (const char *fname, const char *pname)
 339 {
 340   char *sfrname;
 341   const char *dot_framework = ".framework/";
 342   const char *bufptr;
 343   int sfrname_len, i, fname_len;
 344   struct cpp_dir *fast_dir;
 345   static struct cpp_dir subframe_dir;
 346   struct stat st;
 347
 348   bufptr = strchr (fname, '/');
 349
 350   /* Subframework files must have / in the name.  */
 351   if (bufptr == 0)
 352     return 0;
 353
 354   fname_len = bufptr - fname;
 355   fast_dir = find_framework (fname, fname_len);
 356
 357   /* Sub framework header filename includes parent framework name and
 358      header name in the "CarbonCore/OSUtils.h" form. If it does not
 359      include slash it is not a sub framework include.  */
 360   bufptr = strstr (pname, dot_framework);
 361
 362   /* If the parent header is not of any framework, then this header
 363      cannot be part of any subframework.  */
 364   if (!bufptr)
 365     return 0;
 366
 367   /* Now translate. For example,                  +- bufptr
 368      fname = CarbonCore/OSUtils.h                 |
 369      pname = /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h
 370      into
 371      sfrname = /System/Library/Frameworks/Foundation.framework/Frameworks/CarbonCore.framework/Headers/OSUtils.h */
 372
 373   sfrname = XNEWVEC (char, strlen (pname) + strlen (fname) + 2 +
 374                               strlen ("Frameworks/") + strlen (".framework/")
 375                               + strlen ("PrivateHeaders"));
 376
 377   bufptr += strlen (dot_framework);
 378
 379   sfrname_len = bufptr - pname;
 380
 381   memcpy (&sfrname[0], pname, sfrname_len);
 382
 383   memcpy (&sfrname[sfrname_len], "Frameworks/", strlen ("Frameworks/"));
 384   sfrname_len += strlen("Frameworks/");
 385
 386   memcpy (&sfrname[sfrname_len], fname, fname_len);
 387   sfrname_len += fname_len;
 388
 389   memcpy (&sfrname[sfrname_len], ".framework/", strlen (".framework/"));
 390   sfrname_len += strlen (".framework/");
 391
 392   /* Append framework_header_dirs and header file name */
 393   for (i = 0; framework_header_dirs[i].dirName; i++)
 394     {
 395       memcpy (&sfrname[sfrname_len],
 396               framework_header_dirs[i].dirName,
 397               framework_header_dirs[i].dirNameLen);
 398       strcpy (&sfrname[sfrname_len + framework_header_dirs[i].dirNameLen],
 399               &fname[fname_len]);
 400
 401       if (stat (sfrname, &st) == 0)
 402         {
 403           if (fast_dir != &subframe_dir)
 404             {
 405               if (fast_dir)
 406                 warning (0, "subframework include %s conflicts with framework include",
 407                          fname);
 408               else
 409                 add_framework (fname, fname_len, &subframe_dir);
 410             }
 411
 412           return sfrname;
 413         }
 414     }
 415   free (sfrname);
 416
 417   return 0;
 418 }
 419
 420 /* Add PATH to the system includes. PATH must be malloc-ed and
 421    NUL-terminated.  System framework paths are C++ aware.  */
 422
 423 static void
 424 add_system_framework_path (char *path)
 425 {
 426   int cxx_aware = 1;
 427   cpp_dir *p;
 428
 429   p = XNEW (cpp_dir);
 430   p->next = NULL;
 431   p->name = path;
 432   p->sysp = 1 + !cxx_aware;
 433   p->construct = framework_construct_pathname;
 434   using_frameworks = 1;
 435
 436   add_cpp_dir_path (p, INC_SYSTEM);
 437 }
 438
 439 /* Add PATH to the bracket includes. PATH must be malloc-ed and
 440    NUL-terminated.  */
 441
 442 void
 443 add_framework_path (char *path)
 444 {
 445   cpp_dir *p;
 446
 447   p = XNEW (cpp_dir);
 448   p->next = NULL;
 449   p->name = path;
 450   p->sysp = 0;
 451   p->construct = framework_construct_pathname;
 452   using_frameworks = 1;
 453
 454   add_cpp_dir_path (p, INC_BRACKET);
 455 }
 456
 457 static const char *framework_defaults [] =
 458   {
 459     "/System/Library/Frameworks",
 460     "/Library/Frameworks",
 461   };
 462
 463 /* Register the GNU objective-C runtime include path if STDINC.  */
 464
 465 void
 466 darwin_register_objc_includes (const char *sysroot, const char *iprefix,
 467                                int stdinc)
 468 {
 469   const char *fname;
 470   size_t len;
 471   /* We do not do anything if we do not want the standard includes. */
 472   if (!stdinc)
 473     return;
 474
 475   fname = GCC_INCLUDE_DIR "-gnu-runtime";
 476
 477   /* Register the GNU OBJC runtime include path if we are compiling  OBJC
 478     with GNU-runtime.  */
 479
 480   if (c_dialect_objc () && !flag_next_runtime)
 481     {
 482       char *str;
 483       /* See if our directory starts with the standard prefix.
 484          "Translate" them, i.e. replace /usr/local/lib/gcc... with
 485          IPREFIX and search them first.  */
 486       if (iprefix && (len = cpp_GCC_INCLUDE_DIR_len) != 0 && !sysroot
 487           && !strncmp (fname, cpp_GCC_INCLUDE_DIR, len))
 488         {
 489           str = concat (iprefix, fname + len, NULL);
 490           /* FIXME: wrap the headers for C++awareness.  */
 491           add_path (str, INC_SYSTEM, /*c++aware=*/false, false);
 492         }
 493
 494       /* Should this directory start with the sysroot?  */
 495       if (sysroot)
 496         str = concat (sysroot, fname, NULL);
 497       else
 498         str = update_path (fname, "");
 499
 500       add_path (str, INC_SYSTEM, /*c++aware=*/false, false);
 501     }
 502 }
 503
 504
 505 /* Register all the system framework paths if STDINC is true and setup
 506    the missing_header callback for subframework searching if any
 507    frameworks had been registered.  */
 508
 509 void
 510 darwin_register_frameworks (const char *sysroot,
 511                             const char *iprefix ATTRIBUTE_UNUSED, int stdinc)
 512 {
 513   if (stdinc)
 514     {
 515       size_t i;
 516
 517       /* Setup default search path for frameworks.  */
 518       for (i=0; i<sizeof (framework_defaults)/sizeof(const char *); ++i)
 519         {
 520           char *str;
 521           if (sysroot)
 522             str = concat (sysroot, xstrdup (framework_defaults [i]), NULL);
 523           else
 524             str = xstrdup (framework_defaults[i]);
 525           /* System Framework headers are cxx aware.  */
 526           add_system_framework_path (str);
 527         }
 528     }
 529
 530   if (using_frameworks)
 531     cpp_get_callbacks (parse_in)->missing_header = find_subframework_header;
 532 }
 533
 534 /* Search for HEADER in context dependent way.  The return value is
 535    the malloced name of a header to try and open, if any, or NULL
 536    otherwise.  This is called after normal header lookup processing
 537    fails to find a header.  We search each file in the include stack,
 538    using FUNC, starting from the most deeply nested include and
 539    finishing with the main input file.  We stop searching when FUNC
 540    returns nonzero.  */
 541
 542 static const char*
 543 find_subframework_header (cpp_reader *pfile, const char *header, cpp_dir **dirp)
 544 {
 545   const char *fname = header;
 546   struct cpp_buffer *b;
 547   const char *n;
 548
 549   for (b = cpp_get_buffer (pfile);
 550        b && cpp_get_file (b) && cpp_get_path (cpp_get_file (b));
 551        b = cpp_get_prev (b))
 552     {
 553       n = find_subframework_file (fname, cpp_get_path (cpp_get_file (b)));
 554       if (n)
 555         {
 556           /* Logically, the place where we found the subframework is
 557              the place where we found the Framework that contains the
 558              subframework.  This is useful for tracking wether or not
 559              we are in a system header.  */
 560           *dirp = cpp_get_dir (cpp_get_file (b));
 561           return n;
 562         }
 563     }
 564
 565   return 0;
 566 }
 567
 568 /* Given an OS X version VERSION_STR, return it as a statically-allocated array
 569    of three integers. If VERSION_STR is invalid, return NULL.
 570
 571    VERSION_STR must consist of one, two, or three tokens, each separated by
 572    a single period.  Each token must contain only the characters '0' through
 573    '9' and is converted to an equivalent non-negative decimal integer. Omitted
 574    tokens become zeros.  For example:
 575
 576         "10"              becomes       {10,0,0}
 577         "10.10"           becomes       {10,10,0}
 578         "10.10.1"         becomes       {10,10,1}
 579         "10.000010.1"     becomes       {10,10,1}
 580         "10.010.001"      becomes       {10,10,1}
 581         "000010.10.00001" becomes       {10,10,1}
 582         ".9.1"            is invalid
 583         "10..9"           is invalid
 584         "10.10."          is invalid  */
 585
 586 enum version_components { MAJOR, MINOR, TINY };
 587
 588 static const unsigned long *
 589 parse_version (const char *version_str)
 590 {
 591   size_t version_len;
 592   char *end;
 593   static unsigned long version_array[3];
 594
 595   version_len = strlen (version_str);
 596   if (version_len < 1)
 597     return NULL;
 598
 599   /* Version string must consist of digits and periods only.  */
 600   if (strspn (version_str, "0123456789.") != version_len)
 601     return NULL;
 602
 603   if (!ISDIGIT (version_str[0]) || !ISDIGIT (version_str[version_len - 1]))
 604     return NULL;
 605
 606   version_array[MAJOR] = strtoul (version_str, &end, 10);
 607   version_str = end + ((*end == '.') ? 1 : 0);
 608
 609   /* Version string must not contain adjacent periods.  */
 610   if (*version_str == '.')
 611     return NULL;
 612
 613   version_array[MINOR] = strtoul (version_str, &end, 10);
 614   version_str = end + ((*end == '.') ? 1 : 0);
 615
 616   version_array[TINY] = strtoul (version_str, &end, 10);
 617
 618   /* Version string must contain no more than three tokens.  */
 619   if (*end != '\0')
 620     return NULL;
 621
 622   return version_array;
 623 }
 624
 625 /* Given VERSION -- a three-component OS X version represented as an array of
 626    non-negative integers -- return a statically-allocated string suitable for
 627    the legacy __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ macro.  If VERSION
 628    is invalid and cannot be coerced into a valid form, return NULL.
 629
 630    The legacy format is a four-character string -- two chars for the major
 631    number and one each for the minor and tiny numbers.  Minor and tiny numbers
 632    from 10 through 99 are permitted but are clamped to 9 (for example, {10,9,10}
 633    produces "1099").  If VERSION contains numbers greater than 99, it is
 634    rejected.  */
 635
 636 static const char *
 637 version_as_legacy_macro (const unsigned long *version)
 638 {
 639   unsigned long major, minor, tiny;
 640   static char result[5];
 641
 642   major = version[MAJOR];
 643   minor = version[MINOR];
 644   tiny = version[TINY];
 645
 646   if (major > 99 || minor > 99 || tiny > 99)
 647     return NULL;
 648
 649   minor = ((minor > 9) ? 9 : minor);
 650   tiny = ((tiny > 9) ? 9 : tiny);
 651
 652   if (sprintf (result, "%lu%lu%lu", major, minor, tiny) != 4)
 653     return NULL;
 654
 655   return result;
 656 }
 657
 658 /* Given VERSION -- a three-component OS X version represented as an array of
 659    non-negative integers -- return a statically-allocated string suitable for
 660    the modern __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ macro.  If VERSION
 661    is invalid, return NULL.
 662
 663    The modern format is a six-character string -- two chars for each component,
 664    with zero-padding if necessary (for example, {10,10,1} produces "101001"). If
 665    VERSION contains numbers greater than 99, it is rejected.  */
 666
 667 static const char *
 668 version_as_modern_macro (const unsigned long *version)
 669 {
 670   unsigned long major, minor, tiny;
 671   static char result[7];
 672
 673   major = version[MAJOR];
 674   minor = version[MINOR];
 675   tiny = version[TINY];
 676
 677   if (major > 99 || minor > 99 || tiny > 99)
 678     return NULL;
 679
 680   if (sprintf (result, "%02lu%02lu%02lu", major, minor, tiny) != 6)
 681     return NULL;
 682
 683   return result;
 684 }
 685
 686 /* Return the value of darwin_macosx_version_min, suitably formatted for the
 687    __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ macro.  Values representing
 688    OS X 10.9 and earlier are encoded using the legacy four-character format,
 689    while 10.10 and later use a modern six-character format.  (For example,
 690    "10.9" produces "1090", and "10.10.1" produces "101001".)  If
 691    darwin_macosx_version_min is invalid and cannot be coerced into a valid
 692    form, print a warning and return "1000".  */
 693
 694 static const char *
 695 macosx_version_as_macro (void)
 696 {
 697   const unsigned long *version_array;
 698   const char *version_macro;
 699
 700   version_array = parse_version (darwin_macosx_version_min);
 701   if (!version_array)
 702     goto fail;
 703
 704   if (version_array[MAJOR] != 10)
 705     goto fail;
 706
 707   if (version_array[MINOR] < 10)
 708     version_macro = version_as_legacy_macro (version_array);
 709   else
 710     version_macro = version_as_modern_macro (version_array);
 711
 712   if (!version_macro)
 713     goto fail;
 714
 715   return version_macro;
 716
 717  fail:
 718   error ("unknown value %qs of -mmacosx-version-min",
 719          darwin_macosx_version_min);
 720   return "1000";
 721 }
 722
 723 /* Define additional CPP flags for Darwin.   */
 724
 725 #define builtin_define(TXT) cpp_define (pfile, TXT)
 726
 727 void
 728 darwin_cpp_builtins (cpp_reader *pfile)
 729 {
 730   builtin_define ("__MACH__");
 731   builtin_define ("__APPLE__");
 732
 733   /* __APPLE_CC__ is defined as some old Apple include files expect it
 734      to be defined and won't work if it isn't.  */
 735   builtin_define_with_value ("__APPLE_CC__", "1", false);
 736
 737   if (darwin_constant_cfstrings)
 738     builtin_define ("__CONSTANT_CFSTRINGS__");
 739
 740   builtin_define_with_value ("__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__",
 741                              macosx_version_as_macro(), false);
 742
 743   /* Since we do not (at 4.6) support ObjC gc for the NeXT runtime, the
 744      following will cause a syntax error if one tries to compile gc attributed
 745      items.  However, without this, NeXT system headers cannot be parsed
 746      properly (on systems >= darwin 9).  */
 747   if (flag_objc_gc)
 748     {
 749       builtin_define ("__strong=__attribute__((objc_gc(strong)))");
 750       builtin_define ("__weak=__attribute__((objc_gc(weak)))");
 751       builtin_define ("__OBJC_GC__");
 752     }
 753   else
 754     {
 755       builtin_define ("__strong=");
 756       builtin_define ("__weak=");
 757     }
 758
 759   if (CPP_OPTION (pfile, objc) && flag_objc_abi == 2)
 760     builtin_define ("__OBJC2__");
 761 }
 762
 763 /* Handle C family front-end options.  */
 764
 765 static bool
 766 handle_c_option (size_t code,
 767                  const char *arg,
 768                  int value ATTRIBUTE_UNUSED)
 769 {
 770   switch (code)
 771     {
 772     default:
 773       /* Unrecognized options that we said we'd handle turn into
 774          errors if not listed here.  */
 775       return false;
 776
 777     case OPT_iframework:
 778       add_system_framework_path (xstrdup (arg));
 779       break;
 780
 781     case OPT_fapple_kext:
 782       ;
 783     }
 784
 785   /* We recognized the option.  */
 786   return true;
 787 }
 788
 789 /* Allow ObjC* access to CFStrings.  */
 790 static tree
 791 darwin_objc_construct_string (tree str)
 792 {
 793   if (!darwin_constant_cfstrings)
 794     {
 795     /* Even though we are not using CFStrings, place our literal
 796        into the cfstring_htab hash table, so that the
 797        darwin_constant_cfstring_p() function will see it.  */
 798       darwin_enter_string_into_cfstring_table (str);
 799       /* Fall back to NSConstantString.  */
 800       return NULL_TREE;
 801     }
 802
 803   return darwin_build_constant_cfstring (str);
 804 }
 805
 806 /* The string ref type is created as CFStringRef by <CFBase.h> therefore, we
 807    must match for it explicitly, since it's outside the gcc code.  */
 808
 809 static bool
 810 darwin_cfstring_ref_p (const_tree strp)
 811 {
 812   tree tn;
 813   if (!strp || TREE_CODE (strp) != POINTER_TYPE)
 814     return false;
 815
 816   tn = TYPE_NAME (strp);
 817   if (tn)
 818     tn = DECL_NAME (tn);
 819   return (tn
 820           && IDENTIFIER_POINTER (tn)
 821           && !strncmp (IDENTIFIER_POINTER (tn), "CFStringRef", 8));
 822 }
 823
 824 /* At present the behavior of this is undefined and it does nothing.  */
 825 static void
 826 darwin_check_cfstring_format_arg (tree ARG_UNUSED (format_arg),
 827                                   tree ARG_UNUSED (args_list))
 828 {
 829 }
 830
 831 /* The extra format types we recognize.  */
 832 EXPORTED_CONST format_kind_info darwin_additional_format_types[] = {
 833   { "CFString",   NULL,  NULL, NULL, NULL,
 834     NULL, NULL,
 835     FMT_FLAG_ARG_CONVERT|FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL, 0, 0, 0, 0, 0, 0,
 836     NULL, NULL
 837   }
 838 };
 839
 840
 841 /* Support routines to dump the class references for NeXT ABI v1, aka
 842    32-bits ObjC-2.0, as top-level asms.
 843    The following two functions should only be called from
 844    objc/objc-next-runtime-abi-01.c.  */
 845
 846 static void
 847 darwin_objc_declare_unresolved_class_reference (const char *name)
 848 {
 849   const char *lazy_reference = ".lazy_reference\t";
 850   const char *hard_reference = ".reference\t";
 851   const char *reference = MACHOPIC_INDIRECT ? lazy_reference : hard_reference;
 852   size_t len = strlen (reference) + strlen(name) + 2;
 853   char *buf = (char *) alloca (len);
 854
 855   gcc_checking_assert (!strncmp (name, ".objc_class_name_", 17));
 856
 857   snprintf (buf, len, "%s%s", reference, name);
 858   symtab->finalize_toplevel_asm (build_string (strlen (buf), buf));
 859 }
 860
 861 static void
 862 darwin_objc_declare_class_definition (const char *name)
 863 {
 864   const char *xname = targetm.strip_name_encoding (name);
 865   size_t len = strlen (xname) + 7 + 5;
 866   char *buf = (char *) alloca (len);
 867
 868   gcc_checking_assert (!strncmp (name, ".objc_class_name_", 17)
 869                        || !strncmp (name, "*.objc_category_name_", 21));
 870
 871   /* Mimic default_globalize_label.  */
 872   snprintf (buf, len, ".globl\t%s", xname);
 873   symtab->finalize_toplevel_asm (build_string (strlen (buf), buf));
 874
 875   snprintf (buf, len, "%s = 0", xname);
 876   symtab->finalize_toplevel_asm (build_string (strlen (buf), buf));
 877 }
 878
 879 #undef  TARGET_HANDLE_C_OPTION
 880 #define TARGET_HANDLE_C_OPTION handle_c_option
 881
 882 #undef  TARGET_OBJC_CONSTRUCT_STRING_OBJECT
 883 #define TARGET_OBJC_CONSTRUCT_STRING_OBJECT darwin_objc_construct_string
 884
 885 #undef  TARGET_OBJC_DECLARE_UNRESOLVED_CLASS_REFERENCE
 886 #define TARGET_OBJC_DECLARE_UNRESOLVED_CLASS_REFERENCE \
 887         darwin_objc_declare_unresolved_class_reference
 888
 889 #undef  TARGET_OBJC_DECLARE_CLASS_DEFINITION
 890 #define TARGET_OBJC_DECLARE_CLASS_DEFINITION \
 891         darwin_objc_declare_class_definition
 892
 893 #undef  TARGET_STRING_OBJECT_REF_TYPE_P
 894 #define TARGET_STRING_OBJECT_REF_TYPE_P darwin_cfstring_ref_p
 895
 896 #undef TARGET_CHECK_STRING_OBJECT_FORMAT_ARG
 897 #define TARGET_CHECK_STRING_OBJECT_FORMAT_ARG darwin_check_cfstring_format_arg
 898
 899 struct gcc_targetcm targetcm = TARGETCM_INITIALIZER;