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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 std;
  76   char cplusplus_comments;
  77   char digraphs;
  78 };
  79
  80 static const struct lang_flags lang_defaults[] =
  81 { /*              c99 c++ xnum std  //   digr  */
  82   /* GNUC89 */  { 0,  0,  1,   0,   1,   1     },
  83   /* GNUC99 */  { 1,  0,  1,   0,   1,   1     },
  84   /* STDC89 */  { 0,  0,  0,   1,   0,   0     },
  85   /* STDC94 */  { 0,  0,  0,   1,   0,   1     },
  86   /* STDC99 */  { 1,  0,  1,   1,   1,   1     },
  87   /* GNUCXX */  { 0,  1,  1,   0,   1,   1     },
  88   /* CXX98  */  { 0,  1,  1,   1,   1,   1     },
  89   /* ASM    */  { 0,  0,  1,   0,   1,   0     }
  90 };
  91
  92 /* Sets internal flags correctly for a given language.  */
  93 void
  94 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
  95 {
  96   const struct lang_flags *l = &lang_defaults[(int) lang];
  97
  98   CPP_OPTION (pfile, lang) = lang;
  99
 100   CPP_OPTION (pfile, c99)                = l->c99;
 101   CPP_OPTION (pfile, cplusplus)          = l->cplusplus;
 102   CPP_OPTION (pfile, extended_numbers)   = l->extended_numbers;
 103   CPP_OPTION (pfile, std)                = l->std;
 104   CPP_OPTION (pfile, trigraphs)          = l->std;
 105   CPP_OPTION (pfile, cplusplus_comments) = l->cplusplus_comments;
 106   CPP_OPTION (pfile, digraphs)           = l->digraphs;
 107 }
 108
 109 /* Initialize library global state.  */
 110 static void
 111 init_library (void)
 112 {
 113   static int initialized = 0;
 114
 115   if (! initialized)
 116     {
 117       initialized = 1;
 118
 119       /* Set up the trigraph map.  This doesn't need to do anything if
 120          we were compiled with a compiler that supports C99 designated
 121          initializers.  */
 122       init_trigraph_map ();
 123
 124 #ifdef ENABLE_NLS
 125        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 126 #endif
 127     }
 128 }
 129
 130 /* Initialize a cpp_reader structure.  */
 131 cpp_reader *
 132 cpp_create_reader (enum c_lang lang, hash_table *table,
 133                    struct line_maps *line_table)
 134 {
 135   cpp_reader *pfile;
 136
 137   /* Initialize this instance of the library if it hasn't been already.  */
 138   init_library ();
 139
 140   pfile = xcalloc (1, sizeof (cpp_reader));
 141
 142   cpp_set_lang (pfile, lang);
 143   CPP_OPTION (pfile, warn_multichar) = 1;
 144   CPP_OPTION (pfile, discard_comments) = 1;
 145   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 146   CPP_OPTION (pfile, show_column) = 1;
 147   CPP_OPTION (pfile, tabstop) = 8;
 148   CPP_OPTION (pfile, operator_names) = 1;
 149   CPP_OPTION (pfile, warn_trigraphs) = 2;
 150   CPP_OPTION (pfile, warn_endif_labels) = 1;
 151   CPP_OPTION (pfile, warn_deprecated) = 1;
 152   CPP_OPTION (pfile, warn_long_long) = !CPP_OPTION (pfile, c99);
 153   CPP_OPTION (pfile, dollars_in_ident) = 1;
 154   CPP_OPTION (pfile, warn_dollars) = 1;
 155   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 156
 157   /* Default CPP arithmetic to something sensible for the host for the
 158      benefit of dumb users like fix-header.  */
 159   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 160   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 161   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 162   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 163   CPP_OPTION (pfile, unsigned_char) = 0;
 164   CPP_OPTION (pfile, unsigned_wchar) = 1;
 165   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 166
 167   /* Default to no charset conversion.  */
 168   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 169   CPP_OPTION (pfile, wide_charset) = 0;
 170
 171   /* Default the input character set to UTF-8.  */
 172   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 173
 174   /* A fake empty "directory" used as the starting point for files
 175      looked up without a search path.  Name cannot be '/' because we
 176      don't want to prepend anything at all to filenames using it.  All
 177      other entries are correct zero-initialized.  */
 178   pfile->no_search_path.name = (char *) "";
 179
 180   /* Initialize the line map.  */
 181   pfile->line_table = line_table;
 182
 183   /* Initialize lexer state.  */
 184   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 185
 186   /* Set up static tokens.  */
 187   pfile->avoid_paste.type = CPP_PADDING;
 188   pfile->avoid_paste.val.source = NULL;
 189   pfile->eof.type = CPP_EOF;
 190   pfile->eof.flags = 0;
 191
 192   /* Create a token buffer for the lexer.  */
 193   _cpp_init_tokenrun (&pfile->base_run, 250);
 194   pfile->cur_run = &pfile->base_run;
 195   pfile->cur_token = pfile->base_run.base;
 196
 197   /* Initialize the base context.  */
 198   pfile->context = &pfile->base_context;
 199   pfile->base_context.macro = 0;
 200   pfile->base_context.prev = pfile->base_context.next = 0;
 201
 202   /* Aligned and unaligned storage.  */
 203   pfile->a_buff = _cpp_get_buff (pfile, 0);
 204   pfile->u_buff = _cpp_get_buff (pfile, 0);
 205
 206   /* The expression parser stack.  */
 207   _cpp_expand_op_stack (pfile);
 208
 209   /* Initialize the buffer obstack.  */
 210   _obstack_begin (&pfile->buffer_ob, 0, 0,
 211                   (void *(*) (long)) xmalloc,
 212                   (void (*) (void *)) free);
 213
 214   _cpp_init_files (pfile);
 215
 216   _cpp_init_hashtable (pfile, table);
 217
 218   return pfile;
 219 }
 220
 221 /* Free resources used by PFILE.  Accessing PFILE after this function
 222    returns leads to undefined behavior.  Returns the error count.  */
 223 void
 224 cpp_destroy (cpp_reader *pfile)
 225 {
 226   cpp_context *context, *contextn;
 227   tokenrun *run, *runn;
 228
 229   free (pfile->op_stack);
 230
 231   while (CPP_BUFFER (pfile) != NULL)
 232     _cpp_pop_buffer (pfile);
 233
 234   if (pfile->out.base)
 235     free (pfile->out.base);
 236
 237   if (pfile->macro_buffer)
 238     {
 239       free (pfile->macro_buffer);
 240       pfile->macro_buffer = NULL;
 241       pfile->macro_buffer_len = 0;
 242     }
 243
 244   if (pfile->deps)
 245     deps_free (pfile->deps);
 246   obstack_free (&pfile->buffer_ob, 0);
 247
 248   _cpp_destroy_hashtable (pfile);
 249   _cpp_cleanup_files (pfile);
 250   _cpp_destroy_iconv (pfile);
 251
 252   _cpp_free_buff (pfile->a_buff);
 253   _cpp_free_buff (pfile->u_buff);
 254   _cpp_free_buff (pfile->free_buffs);
 255
 256   for (run = &pfile->base_run; run; run = runn)
 257     {
 258       runn = run->next;
 259       free (run->base);
 260       if (run != &pfile->base_run)
 261         free (run);
 262     }
 263
 264   for (context = pfile->base_context.next; context; context = contextn)
 265     {
 266       contextn = context->next;
 267       free (context);
 268     }
 269
 270   free (pfile);
 271 }
 272
 273 /* This structure defines one built-in identifier.  A node will be
 274    entered in the hash table under the name NAME, with value VALUE.
 275
 276    There are two tables of these.  builtin_array holds all the
 277    "builtin" macros: these are handled by builtin_macro() in
 278    macro.c.  Builtin is somewhat of a misnomer -- the property of
 279    interest is that these macros require special code to compute their
 280    expansions.  The value is a "builtin_type" enumerator.
 281
 282    operator_array holds the C++ named operators.  These are keywords
 283    which act as aliases for punctuators.  In C++, they cannot be
 284    altered through #define, and #if recognizes them as operators.  In
 285    C, these are not entered into the hash table at all (but see
 286    <iso646.h>).  The value is a token-type enumerator.  */
 287 struct builtin
 288 {
 289   const uchar *name;
 290   unsigned short len;
 291   unsigned short value;
 292 };
 293
 294 #define B(n, t)    { DSC(n), t }
 295 static const struct builtin builtin_array[] =
 296 {
 297   B("__TIME__",          BT_TIME),
 298   B("__DATE__",          BT_DATE),
 299   B("__FILE__",          BT_FILE),
 300   B("__BASE_FILE__",     BT_BASE_FILE),
 301   B("__LINE__",          BT_SPECLINE),
 302   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
 303   /* Keep builtins not used for -traditional-cpp at the end, and
 304      update init_builtins() if any more are added.  */
 305   B("_Pragma",           BT_PRAGMA),
 306   B("__STDC__",          BT_STDC),
 307 };
 308
 309 static const struct builtin operator_array[] =
 310 {
 311   B("and",      CPP_AND_AND),
 312   B("and_eq",   CPP_AND_EQ),
 313   B("bitand",   CPP_AND),
 314   B("bitor",    CPP_OR),
 315   B("compl",    CPP_COMPL),
 316   B("not",      CPP_NOT),
 317   B("not_eq",   CPP_NOT_EQ),
 318   B("or",       CPP_OR_OR),
 319   B("or_eq",    CPP_OR_EQ),
 320   B("xor",      CPP_XOR),
 321   B("xor_eq",   CPP_XOR_EQ)
 322 };
 323 #undef B
 324
 325 /* Mark the C++ named operators in the hash table.  */
 326 static void
 327 mark_named_operators (cpp_reader *pfile)
 328 {
 329   const struct builtin *b;
 330
 331   for (b = operator_array;
 332        b < (operator_array + ARRAY_SIZE (operator_array));
 333        b++)
 334     {
 335       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 336       hp->flags |= NODE_OPERATOR;
 337       hp->is_directive = 0;
 338       hp->directive_index = b->value;
 339     }
 340 }
 341
 342 /* Read the builtins table above and enter them, and language-specific
 343    macros, into the hash table.  HOSTED is true if this is a hosted
 344    environment.  */
 345 void
 346 cpp_init_builtins (cpp_reader *pfile, int hosted)
 347 {
 348   const struct builtin *b;
 349   size_t n = ARRAY_SIZE (builtin_array);
 350
 351   if (CPP_OPTION (pfile, traditional))
 352     n -= 2;
 353
 354   for(b = builtin_array; b < builtin_array + n; b++)
 355     {
 356       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 357       hp->type = NT_MACRO;
 358       hp->flags |= NODE_BUILTIN | NODE_WARN;
 359       hp->value.builtin = b->value;
 360     }
 361
 362   if (CPP_OPTION (pfile, cplusplus))
 363     _cpp_define_builtin (pfile, "__cplusplus 1");
 364   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 365     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 366   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 367     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 368   else if (CPP_OPTION (pfile, c99))
 369     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 370
 371   if (hosted)
 372     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 373   else
 374     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 375
 376   if (CPP_OPTION (pfile, objc))
 377     _cpp_define_builtin (pfile, "__OBJC__ 1");
 378 }
 379
 380 /* Sanity-checks are dependent on command-line options, so it is
 381    called as a subroutine of cpp_read_main_file ().  */
 382 #if ENABLE_CHECKING
 383 static void sanity_checks (cpp_reader *);
 384 static void sanity_checks (cpp_reader *pfile)
 385 {
 386   cppchar_t test = 0;
 387   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 388
 389   /* Sanity checks for assumptions about CPP arithmetic and target
 390      type precisions made by cpplib.  */
 391   test--;
 392   if (test < 1)
 393     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 394
 395   if (CPP_OPTION (pfile, precision) > max_precision)
 396     cpp_error (pfile, CPP_DL_ICE,
 397                "preprocessor arithmetic has maximum precision of %lu bits;"
 398                " target requires %lu bits",
 399                (unsigned long) max_precision,
 400                (unsigned long) CPP_OPTION (pfile, precision));
 401
 402   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 403     cpp_error (pfile, CPP_DL_ICE,
 404                "CPP arithmetic must be at least as precise as a target int");
 405
 406   if (CPP_OPTION (pfile, char_precision) < 8)
 407     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 408
 409   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 410     cpp_error (pfile, CPP_DL_ICE,
 411                "target wchar_t is narrower than target char");
 412
 413   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 414     cpp_error (pfile, CPP_DL_ICE,
 415                "target int is narrower than target char");
 416
 417   /* This is assumed in eval_token() and could be fixed if necessary.  */
 418   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 419     cpp_error (pfile, CPP_DL_ICE,
 420                "CPP half-integer narrower than CPP character");
 421
 422   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 423     cpp_error (pfile, CPP_DL_ICE,
 424                "CPP on this host cannot handle wide character constants over"
 425                " %lu bits, but the target requires %lu bits",
 426                (unsigned long) BITS_PER_CPPCHAR_T,
 427                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 428 }
 429 #else
 430 # define sanity_checks(PFILE)
 431 #endif
 432
 433 /* This is called after options have been parsed, and partially
 434    processed.  */
 435 void
 436 cpp_post_options (cpp_reader *pfile)
 437 {
 438   sanity_checks (pfile);
 439
 440   post_options (pfile);
 441
 442   /* Mark named operators before handling command line macros.  */
 443   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 444     mark_named_operators (pfile);
 445 }
 446
 447 /* Setup for processing input from the file named FNAME, or stdin if
 448    it is the empty string.  Return the original filename
 449    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 450 const char *
 451 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 452 {
 453   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 454     {
 455       if (!pfile->deps)
 456         pfile->deps = deps_init ();
 457
 458       /* Set the default target (if there is none already).  */
 459       deps_add_default_target (pfile->deps, fname);
 460     }
 461
 462   pfile->main_file
 463     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0);
 464   if (_cpp_find_failed (pfile->main_file))
 465     return NULL;
 466
 467   _cpp_stack_file (pfile, pfile->main_file, false);
 468
 469   /* For foo.i, read the original filename foo.c now, for the benefit
 470      of the front ends.  */
 471   if (CPP_OPTION (pfile, preprocessed))
 472     {
 473       read_original_filename (pfile);
 474       fname = pfile->line_table->maps[pfile->line_table->used-1].to_file;
 475     }
 476   return fname;
 477 }
 478
 479 /* For preprocessed files, if the first tokens are of the form # NUM.
 480    handle the directive so we know the original file name.  This will
 481    generate file_change callbacks, which the front ends must handle
 482    appropriately given their state of initialization.  */
 483 static void
 484 read_original_filename (cpp_reader *pfile)
 485 {
 486   const cpp_token *token, *token1;
 487
 488   /* Lex ahead; if the first tokens are of the form # NUM, then
 489      process the directive, otherwise back up.  */
 490   token = _cpp_lex_direct (pfile);
 491   if (token->type == CPP_HASH)
 492     {
 493       pfile->state.in_directive = 1;
 494       token1 = _cpp_lex_direct (pfile);
 495       _cpp_backup_tokens (pfile, 1);
 496       pfile->state.in_directive = 0;
 497
 498       /* If it's a #line directive, handle it.  */
 499       if (token1->type == CPP_NUMBER)
 500         {
 501           _cpp_handle_directive (pfile, token->flags & PREV_WHITE);
 502           read_original_directory (pfile);
 503           return;
 504         }
 505     }
 506
 507   /* Backup as if nothing happened.  */
 508   _cpp_backup_tokens (pfile, 1);
 509 }
 510
 511 /* For preprocessed files, if the tokens following the first filename
 512    line is of the form # <line> "/path/name//", handle the
 513    directive so we know the original current directory.  */
 514 static void
 515 read_original_directory (cpp_reader *pfile)
 516 {
 517   const cpp_token *hash, *token;
 518
 519   /* Lex ahead; if the first tokens are of the form # NUM, then
 520      process the directive, otherwise back up.  */
 521   hash = _cpp_lex_direct (pfile);
 522   if (hash->type != CPP_HASH)
 523     {
 524       _cpp_backup_tokens (pfile, 1);
 525       return;
 526     }
 527
 528   token = _cpp_lex_direct (pfile);
 529
 530   if (token->type != CPP_NUMBER)
 531     {
 532       _cpp_backup_tokens (pfile, 2);
 533       return;
 534     }
 535
 536   token = _cpp_lex_direct (pfile);
 537
 538   if (token->type != CPP_STRING
 539       || ! (token->val.str.len >= 5
 540             && token->val.str.text[token->val.str.len-2] == '/'
 541             && token->val.str.text[token->val.str.len-3] == '/'))
 542     {
 543       _cpp_backup_tokens (pfile, 3);
 544       return;
 545     }
 546
 547   if (pfile->cb.dir_change)
 548     {
 549       char *debugdir = alloca (token->val.str.len - 3);
 550
 551       memcpy (debugdir, (const char *) token->val.str.text + 1,
 552               token->val.str.len - 4);
 553       debugdir[token->val.str.len - 4] = '\0';
 554
 555       pfile->cb.dir_change (pfile, debugdir);
 556     }
 557 }
 558
 559 /* This is called at the end of preprocessing.  It pops the last
 560    buffer and writes dependency output, and returns the number of
 561    errors.
 562
 563    Maybe it should also reset state, such that you could call
 564    cpp_start_read with a new filename to restart processing.  */
 565 int
 566 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 567 {
 568   /* Warn about unused macros before popping the final buffer.  */
 569   if (CPP_OPTION (pfile, warn_unused_macros))
 570     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 571
 572   /* lex.c leaves the final buffer on the stack.  This it so that
 573      it returns an unending stream of CPP_EOFs to the client.  If we
 574      popped the buffer, we'd dereference a NULL buffer pointer and
 575      segfault.  It's nice to allow the client to do worry-free excess
 576      cpp_get_token calls.  */
 577   while (pfile->buffer)
 578     _cpp_pop_buffer (pfile);
 579
 580   /* Don't write the deps file if there are errors.  */
 581   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 582       && deps_stream && pfile->errors == 0)
 583     {
 584       deps_write (pfile->deps, deps_stream, 72);
 585
 586       if (CPP_OPTION (pfile, deps.phony_targets))
 587         deps_phony_targets (pfile->deps, deps_stream);
 588     }
 589
 590   /* Report on headers that could use multiple include guards.  */
 591   if (CPP_OPTION (pfile, print_include_names))
 592     _cpp_report_missing_guards (pfile);
 593
 594   return pfile->errors;
 595 }
 596
 597 static void
 598 post_options (cpp_reader *pfile)
 599 {
 600   /* -Wtraditional is not useful in C++ mode.  */
 601   if (CPP_OPTION (pfile, cplusplus))
 602     CPP_OPTION (pfile, warn_traditional) = 0;
 603
 604   /* Permanently disable macro expansion if we are rescanning
 605      preprocessed text.  Read preprocesed source in ISO mode.  */
 606   if (CPP_OPTION (pfile, preprocessed))
 607     {
 608       pfile->state.prevent_expansion = 1;
 609       CPP_OPTION (pfile, traditional) = 0;
 610     }
 611
 612   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 613     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 614
 615   if (CPP_OPTION (pfile, traditional))
 616     {
 617       CPP_OPTION (pfile, cplusplus_comments) = 0;
 618
 619       /* Traditional CPP does not accurately track column information.  */
 620       CPP_OPTION (pfile, show_column) = 0;
 621       CPP_OPTION (pfile, trigraphs) = 0;
 622       CPP_OPTION (pfile, warn_trigraphs) = 0;
 623     }
 624 }