libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   4    Contributed by Per Bothner, 1994-95.
   5    Based on CCCP program by Paul Rubin, June 1986
   6    Adapted to ANSI C, Richard Stallman, Jan 1987
   7
   8 This program is free software; you can redistribute it and/or modify it
   9 under the terms of the GNU General Public License as published by the
  10 Free Software Foundation; either version 2, or (at your option) any
  11 later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "cpplib.h"
  25 #include "internal.h"
  26 #include "mkdeps.h"
  27 #include "localedir.h"
  28
  29 static void init_library (void);
  30 static void mark_named_operators (cpp_reader *);
  31 static void read_original_filename (cpp_reader *);
  32 static void read_original_directory (cpp_reader *);
  33 static void post_options (cpp_reader *);
  34
  35 /* If we have designated initializers (GCC >2.7) these tables can be
  36    initialized, constant data.  Otherwise, they have to be filled in at
  37    runtime.  */
  38 #if HAVE_DESIGNATED_INITIALIZERS
  39
  40 #define init_trigraph_map()  /* Nothing.  */
  41 #define TRIGRAPH_MAP \
  42 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
  43
  44 #define END };
  45 #define s(p, v) [p] = v,
  46
  47 #else
  48
  49 #define TRIGRAPH_MAP uchar _cpp_trigraph_map[UCHAR_MAX + 1] = { 0 }; \
  50  static void init_trigraph_map (void) { \
  51  unsigned char *x = _cpp_trigraph_map;
  52
  53 #define END }
  54 #define s(p, v) x[p] = v;
  55
  56 #endif
  57
  58 TRIGRAPH_MAP
  59   s('=', '#')   s(')', ']')     s('!', '|')
  60   s('(', '[')   s('\'', '^')    s('>', '}')
  61   s('/', '\\')  s('<', '{')     s('-', '~')
  62 END
  63
  64 #undef s
  65 #undef END
  66 #undef TRIGRAPH_MAP
  67
  68 /* A set of booleans indicating what CPP features each source language
  69    requires.  */
  70 struct lang_flags
  71 {
  72   char c99;
  73   char cplusplus;
  74   char extended_numbers;
  75   char extended_identifiers;
  76   char std;
  77   char cplusplus_comments;
  78   char digraphs;
  79 };
  80
  81 static const struct lang_flags lang_defaults[] =
  82 { /*              c99 c++ xnum xid std  //   digr  */
  83   /* GNUC89   */  { 0,  0,  1,   0,  0,   1,   1     },
  84   /* GNUC99   */  { 1,  0,  1,   0,  0,   1,   1     },
  85   /* STDC89   */  { 0,  0,  0,   0,  1,   0,   0     },
  86   /* STDC94   */  { 0,  0,  0,   0,  1,   0,   1     },
  87   /* STDC99   */  { 1,  0,  1,   0,  1,   1,   1     },
  88   /* GNUCXX   */  { 0,  1,  1,   0,  0,   1,   1     },
  89   /* CXX98    */  { 0,  1,  1,   0,  1,   1,   1     },
  90   /* GNUCXX0X */  { 1,  1,  1,   0,  0,   1,   1     },
  91   /* CXX0X    */  { 1,  1,  1,   0,  1,   1,   1     },
  92   /* ASM      */  { 0,  0,  1,   0,  0,   1,   0     }
  93   /* xid should be 1 for GNUC99, STDC99, GNUCXX, CXX98, GNUCXX0X, and
  94      CXX0X when no longer experimental (when all uses of identifiers
  95      in the compiler have been audited for correct handling of
  96      extended identifiers).  */
  97 };
  98
  99 /* Sets internal flags correctly for a given language.  */
 100 void
 101 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 102 {
 103   const struct lang_flags *l = &lang_defaults[(int) lang];
 104
 105   CPP_OPTION (pfile, lang) = lang;
 106
 107   CPP_OPTION (pfile, c99)                        = l->c99;
 108   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 109   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 110   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 111   CPP_OPTION (pfile, std)                        = l->std;
 112   CPP_OPTION (pfile, trigraphs)                  = l->std;
 113   CPP_OPTION (pfile, cplusplus_comments)         = l->cplusplus_comments;
 114   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 115 }
 116
 117 /* Initialize library global state.  */
 118 static void
 119 init_library (void)
 120 {
 121   static int initialized = 0;
 122
 123   if (! initialized)
 124     {
 125       initialized = 1;
 126
 127       /* Set up the trigraph map.  This doesn't need to do anything if
 128          we were compiled with a compiler that supports C99 designated
 129          initializers.  */
 130       init_trigraph_map ();
 131
 132 #ifdef ENABLE_NLS
 133        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 134 #endif
 135     }
 136 }
 137
 138 /* Initialize a cpp_reader structure.  */
 139 cpp_reader *
 140 cpp_create_reader (enum c_lang lang, hash_table *table,
 141                    struct line_maps *line_table)
 142 {
 143   cpp_reader *pfile;
 144
 145   /* Initialize this instance of the library if it hasn't been already.  */
 146   init_library ();
 147
 148   pfile = XCNEW (cpp_reader);
 149
 150   cpp_set_lang (pfile, lang);
 151   CPP_OPTION (pfile, warn_multichar) = 1;
 152   CPP_OPTION (pfile, discard_comments) = 1;
 153   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 154   CPP_OPTION (pfile, show_column) = 1;
 155   CPP_OPTION (pfile, tabstop) = 8;
 156   CPP_OPTION (pfile, operator_names) = 1;
 157   CPP_OPTION (pfile, warn_trigraphs) = 2;
 158   CPP_OPTION (pfile, warn_endif_labels) = 1;
 159   CPP_OPTION (pfile, warn_deprecated) = 1;
 160   CPP_OPTION (pfile, warn_long_long) = !CPP_OPTION (pfile, c99);
 161   CPP_OPTION (pfile, dollars_in_ident) = 1;
 162   CPP_OPTION (pfile, warn_dollars) = 1;
 163   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 164   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 165
 166   /* Default CPP arithmetic to something sensible for the host for the
 167      benefit of dumb users like fix-header.  */
 168   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 169   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 170   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 171   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 172   CPP_OPTION (pfile, unsigned_char) = 0;
 173   CPP_OPTION (pfile, unsigned_wchar) = 1;
 174   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 175
 176   /* Default to no charset conversion.  */
 177   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 178   CPP_OPTION (pfile, wide_charset) = 0;
 179
 180   /* Default the input character set to UTF-8.  */
 181   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 182
 183   /* A fake empty "directory" used as the starting point for files
 184      looked up without a search path.  Name cannot be '/' because we
 185      don't want to prepend anything at all to filenames using it.  All
 186      other entries are correct zero-initialized.  */
 187   pfile->no_search_path.name = (char *) "";
 188
 189   /* Initialize the line map.  */
 190   pfile->line_table = line_table;
 191
 192   /* Initialize lexer state.  */
 193   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 194
 195   /* Set up static tokens.  */
 196   pfile->avoid_paste.type = CPP_PADDING;
 197   pfile->avoid_paste.val.source = NULL;
 198   pfile->eof.type = CPP_EOF;
 199   pfile->eof.flags = 0;
 200
 201   /* Create a token buffer for the lexer.  */
 202   _cpp_init_tokenrun (&pfile->base_run, 250);
 203   pfile->cur_run = &pfile->base_run;
 204   pfile->cur_token = pfile->base_run.base;
 205
 206   /* Initialize the base context.  */
 207   pfile->context = &pfile->base_context;
 208   pfile->base_context.macro = 0;
 209   pfile->base_context.prev = pfile->base_context.next = 0;
 210
 211   /* Aligned and unaligned storage.  */
 212   pfile->a_buff = _cpp_get_buff (pfile, 0);
 213   pfile->u_buff = _cpp_get_buff (pfile, 0);
 214
 215   /* The expression parser stack.  */
 216   _cpp_expand_op_stack (pfile);
 217
 218   /* Initialize the buffer obstack.  */
 219   _obstack_begin (&pfile->buffer_ob, 0, 0,
 220                   (void *(*) (long)) xmalloc,
 221                   (void (*) (void *)) free);
 222
 223   _cpp_init_files (pfile);
 224
 225   _cpp_init_hashtable (pfile, table);
 226
 227   return pfile;
 228 }
 229
 230 /* Free resources used by PFILE.  Accessing PFILE after this function
 231    returns leads to undefined behavior.  Returns the error count.  */
 232 void
 233 cpp_destroy (cpp_reader *pfile)
 234 {
 235   cpp_context *context, *contextn;
 236   tokenrun *run, *runn;
 237
 238   free (pfile->op_stack);
 239
 240   while (CPP_BUFFER (pfile) != NULL)
 241     _cpp_pop_buffer (pfile);
 242
 243   if (pfile->out.base)
 244     free (pfile->out.base);
 245
 246   if (pfile->macro_buffer)
 247     {
 248       free (pfile->macro_buffer);
 249       pfile->macro_buffer = NULL;
 250       pfile->macro_buffer_len = 0;
 251     }
 252
 253   if (pfile->deps)
 254     deps_free (pfile->deps);
 255   obstack_free (&pfile->buffer_ob, 0);
 256
 257   _cpp_destroy_hashtable (pfile);
 258   _cpp_cleanup_files (pfile);
 259   _cpp_destroy_iconv (pfile);
 260
 261   _cpp_free_buff (pfile->a_buff);
 262   _cpp_free_buff (pfile->u_buff);
 263   _cpp_free_buff (pfile->free_buffs);
 264
 265   for (run = &pfile->base_run; run; run = runn)
 266     {
 267       runn = run->next;
 268       free (run->base);
 269       if (run != &pfile->base_run)
 270         free (run);
 271     }
 272
 273   for (context = pfile->base_context.next; context; context = contextn)
 274     {
 275       contextn = context->next;
 276       free (context);
 277     }
 278
 279   free (pfile);
 280 }
 281
 282 /* This structure defines one built-in identifier.  A node will be
 283    entered in the hash table under the name NAME, with value VALUE.
 284
 285    There are two tables of these.  builtin_array holds all the
 286    "builtin" macros: these are handled by builtin_macro() in
 287    macro.c.  Builtin is somewhat of a misnomer -- the property of
 288    interest is that these macros require special code to compute their
 289    expansions.  The value is a "builtin_type" enumerator.
 290
 291    operator_array holds the C++ named operators.  These are keywords
 292    which act as aliases for punctuators.  In C++, they cannot be
 293    altered through #define, and #if recognizes them as operators.  In
 294    C, these are not entered into the hash table at all (but see
 295    <iso646.h>).  The value is a token-type enumerator.  */
 296 struct builtin
 297 {
 298   const uchar *name;
 299   unsigned short len;
 300   unsigned short value;
 301 };
 302
 303 #define B(n, t)    { DSC(n), t }
 304 static const struct builtin builtin_array[] =
 305 {
 306   B("__TIMESTAMP__",     BT_TIMESTAMP),
 307   B("__TIME__",          BT_TIME),
 308   B("__DATE__",          BT_DATE),
 309   B("__FILE__",          BT_FILE),
 310   B("__BASE_FILE__",     BT_BASE_FILE),
 311   B("__LINE__",          BT_SPECLINE),
 312   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
 313   B("__COUNTER__",       BT_COUNTER),
 314   /* Keep builtins not used for -traditional-cpp at the end, and
 315      update init_builtins() if any more are added.  */
 316   B("_Pragma",           BT_PRAGMA),
 317   B("__STDC__",          BT_STDC),
 318 };
 319
 320 static const struct builtin operator_array[] =
 321 {
 322   B("and",      CPP_AND_AND),
 323   B("and_eq",   CPP_AND_EQ),
 324   B("bitand",   CPP_AND),
 325   B("bitor",    CPP_OR),
 326   B("compl",    CPP_COMPL),
 327   B("not",      CPP_NOT),
 328   B("not_eq",   CPP_NOT_EQ),
 329   B("or",       CPP_OR_OR),
 330   B("or_eq",    CPP_OR_EQ),
 331   B("xor",      CPP_XOR),
 332   B("xor_eq",   CPP_XOR_EQ)
 333 };
 334 #undef B
 335
 336 /* Mark the C++ named operators in the hash table.  */
 337 static void
 338 mark_named_operators (cpp_reader *pfile)
 339 {
 340   const struct builtin *b;
 341
 342   for (b = operator_array;
 343        b < (operator_array + ARRAY_SIZE (operator_array));
 344        b++)
 345     {
 346       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 347       hp->flags |= NODE_OPERATOR;
 348       hp->is_directive = 0;
 349       hp->directive_index = b->value;
 350     }
 351 }
 352
 353 /* Read the builtins table above and enter them, and language-specific
 354    macros, into the hash table.  HOSTED is true if this is a hosted
 355    environment.  */
 356 void
 357 cpp_init_builtins (cpp_reader *pfile, int hosted)
 358 {
 359   const struct builtin *b;
 360   size_t n = ARRAY_SIZE (builtin_array);
 361
 362   if (CPP_OPTION (pfile, traditional))
 363     n -= 2;
 364   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 365            || CPP_OPTION (pfile, std))
 366     {
 367       n--;
 368       _cpp_define_builtin (pfile, "__STDC__ 1");
 369     }
 370
 371   for (b = builtin_array; b < builtin_array + n; b++)
 372     {
 373       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 374       hp->type = NT_MACRO;
 375       hp->flags |= NODE_BUILTIN | NODE_WARN;
 376       hp->value.builtin = (enum builtin_type) b->value;
 377     }
 378
 379   if (CPP_OPTION (pfile, cplusplus))
 380     _cpp_define_builtin (pfile, "__cplusplus 1");
 381   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 382     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 383   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 384     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 385   else if (CPP_OPTION (pfile, c99))
 386     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 387
 388   if (hosted)
 389     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 390   else
 391     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 392
 393   if (CPP_OPTION (pfile, objc))
 394     _cpp_define_builtin (pfile, "__OBJC__ 1");
 395 }
 396
 397 /* Sanity-checks are dependent on command-line options, so it is
 398    called as a subroutine of cpp_read_main_file ().  */
 399 #if ENABLE_CHECKING
 400 static void sanity_checks (cpp_reader *);
 401 static void sanity_checks (cpp_reader *pfile)
 402 {
 403   cppchar_t test = 0;
 404   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 405
 406   /* Sanity checks for assumptions about CPP arithmetic and target
 407      type precisions made by cpplib.  */
 408   test--;
 409   if (test < 1)
 410     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 411
 412   if (CPP_OPTION (pfile, precision) > max_precision)
 413     cpp_error (pfile, CPP_DL_ICE,
 414                "preprocessor arithmetic has maximum precision of %lu bits;"
 415                " target requires %lu bits",
 416                (unsigned long) max_precision,
 417                (unsigned long) CPP_OPTION (pfile, precision));
 418
 419   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 420     cpp_error (pfile, CPP_DL_ICE,
 421                "CPP arithmetic must be at least as precise as a target int");
 422
 423   if (CPP_OPTION (pfile, char_precision) < 8)
 424     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 425
 426   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 427     cpp_error (pfile, CPP_DL_ICE,
 428                "target wchar_t is narrower than target char");
 429
 430   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 431     cpp_error (pfile, CPP_DL_ICE,
 432                "target int is narrower than target char");
 433
 434   /* This is assumed in eval_token() and could be fixed if necessary.  */
 435   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 436     cpp_error (pfile, CPP_DL_ICE,
 437                "CPP half-integer narrower than CPP character");
 438
 439   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 440     cpp_error (pfile, CPP_DL_ICE,
 441                "CPP on this host cannot handle wide character constants over"
 442                " %lu bits, but the target requires %lu bits",
 443                (unsigned long) BITS_PER_CPPCHAR_T,
 444                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 445 }
 446 #else
 447 # define sanity_checks(PFILE)
 448 #endif
 449
 450 /* This is called after options have been parsed, and partially
 451    processed.  */
 452 void
 453 cpp_post_options (cpp_reader *pfile)
 454 {
 455   sanity_checks (pfile);
 456
 457   post_options (pfile);
 458
 459   /* Mark named operators before handling command line macros.  */
 460   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 461     mark_named_operators (pfile);
 462 }
 463
 464 /* Setup for processing input from the file named FNAME, or stdin if
 465    it is the empty string.  Return the original filename
 466    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 467 const char *
 468 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 469 {
 470   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 471     {
 472       if (!pfile->deps)
 473         pfile->deps = deps_init ();
 474
 475       /* Set the default target (if there is none already).  */
 476       deps_add_default_target (pfile->deps, fname);
 477     }
 478
 479   pfile->main_file
 480     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0);
 481   if (_cpp_find_failed (pfile->main_file))
 482     return NULL;
 483
 484   _cpp_stack_file (pfile, pfile->main_file, false);
 485
 486   /* For foo.i, read the original filename foo.c now, for the benefit
 487      of the front ends.  */
 488   if (CPP_OPTION (pfile, preprocessed))
 489     {
 490       read_original_filename (pfile);
 491       fname = pfile->line_table->maps[pfile->line_table->used-1].to_file;
 492     }
 493   return fname;
 494 }
 495
 496 /* For preprocessed files, if the first tokens are of the form # NUM.
 497    handle the directive so we know the original file name.  This will
 498    generate file_change callbacks, which the front ends must handle
 499    appropriately given their state of initialization.  */
 500 static void
 501 read_original_filename (cpp_reader *pfile)
 502 {
 503   const cpp_token *token, *token1;
 504
 505   /* Lex ahead; if the first tokens are of the form # NUM, then
 506      process the directive, otherwise back up.  */
 507   token = _cpp_lex_direct (pfile);
 508   if (token->type == CPP_HASH)
 509     {
 510       pfile->state.in_directive = 1;
 511       token1 = _cpp_lex_direct (pfile);
 512       _cpp_backup_tokens (pfile, 1);
 513       pfile->state.in_directive = 0;
 514
 515       /* If it's a #line directive, handle it.  */
 516       if (token1->type == CPP_NUMBER)
 517         {
 518           _cpp_handle_directive (pfile, token->flags & PREV_WHITE);
 519           read_original_directory (pfile);
 520           return;
 521         }
 522     }
 523
 524   /* Backup as if nothing happened.  */
 525   _cpp_backup_tokens (pfile, 1);
 526 }
 527
 528 /* For preprocessed files, if the tokens following the first filename
 529    line is of the form # <line> "/path/name//", handle the
 530    directive so we know the original current directory.  */
 531 static void
 532 read_original_directory (cpp_reader *pfile)
 533 {
 534   const cpp_token *hash, *token;
 535
 536   /* Lex ahead; if the first tokens are of the form # NUM, then
 537      process the directive, otherwise back up.  */
 538   hash = _cpp_lex_direct (pfile);
 539   if (hash->type != CPP_HASH)
 540     {
 541       _cpp_backup_tokens (pfile, 1);
 542       return;
 543     }
 544
 545   token = _cpp_lex_direct (pfile);
 546
 547   if (token->type != CPP_NUMBER)
 548     {
 549       _cpp_backup_tokens (pfile, 2);
 550       return;
 551     }
 552
 553   token = _cpp_lex_direct (pfile);
 554
 555   if (token->type != CPP_STRING
 556       || ! (token->val.str.len >= 5
 557             && token->val.str.text[token->val.str.len-2] == '/'
 558             && token->val.str.text[token->val.str.len-3] == '/'))
 559     {
 560       _cpp_backup_tokens (pfile, 3);
 561       return;
 562     }
 563
 564   if (pfile->cb.dir_change)
 565     {
 566       char *debugdir = (char *) alloca (token->val.str.len - 3);
 567
 568       memcpy (debugdir, (const char *) token->val.str.text + 1,
 569               token->val.str.len - 4);
 570       debugdir[token->val.str.len - 4] = '\0';
 571
 572       pfile->cb.dir_change (pfile, debugdir);
 573     }
 574 }
 575
 576 /* This is called at the end of preprocessing.  It pops the last
 577    buffer and writes dependency output, and returns the number of
 578    errors.
 579
 580    Maybe it should also reset state, such that you could call
 581    cpp_start_read with a new filename to restart processing.  */
 582 int
 583 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 584 {
 585   /* Warn about unused macros before popping the final buffer.  */
 586   if (CPP_OPTION (pfile, warn_unused_macros))
 587     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 588
 589   /* lex.c leaves the final buffer on the stack.  This it so that
 590      it returns an unending stream of CPP_EOFs to the client.  If we
 591      popped the buffer, we'd dereference a NULL buffer pointer and
 592      segfault.  It's nice to allow the client to do worry-free excess
 593      cpp_get_token calls.  */
 594   while (pfile->buffer)
 595     _cpp_pop_buffer (pfile);
 596
 597   /* Don't write the deps file if there are errors.  */
 598   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 599       && deps_stream && pfile->errors == 0)
 600     {
 601       deps_write (pfile->deps, deps_stream, 72);
 602
 603       if (CPP_OPTION (pfile, deps.phony_targets))
 604         deps_phony_targets (pfile->deps, deps_stream);
 605     }
 606
 607   /* Report on headers that could use multiple include guards.  */
 608   if (CPP_OPTION (pfile, print_include_names))
 609     _cpp_report_missing_guards (pfile);
 610
 611   return pfile->errors;
 612 }
 613
 614 static void
 615 post_options (cpp_reader *pfile)
 616 {
 617   /* -Wtraditional is not useful in C++ mode.  */
 618   if (CPP_OPTION (pfile, cplusplus))
 619     CPP_OPTION (pfile, warn_traditional) = 0;
 620
 621   /* Permanently disable macro expansion if we are rescanning
 622      preprocessed text.  Read preprocesed source in ISO mode.  */
 623   if (CPP_OPTION (pfile, preprocessed))
 624     {
 625       pfile->state.prevent_expansion = 1;
 626       CPP_OPTION (pfile, traditional) = 0;
 627     }
 628
 629   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 630     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 631
 632   if (CPP_OPTION (pfile, traditional))
 633     {
 634       CPP_OPTION (pfile, cplusplus_comments) = 0;
 635
 636       /* Traditional CPP does not accurately track column information.  */
 637       CPP_OPTION (pfile, show_column) = 0;
 638       CPP_OPTION (pfile, trigraphs) = 0;
 639       CPP_OPTION (pfile, warn_trigraphs) = 0;
 640     }
 641 }