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, 2007 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 /* Set the line_table entry in PFILE.  This is called after reading a
 231    PCH file, as the old line_table will be incorrect.  */
 232 void
 233 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 234 {
 235   pfile->line_table = line_table;
 236 }
 237
 238 /* Free resources used by PFILE.  Accessing PFILE after this function
 239    returns leads to undefined behavior.  Returns the error count.  */
 240 void
 241 cpp_destroy (cpp_reader *pfile)
 242 {
 243   cpp_context *context, *contextn;
 244   tokenrun *run, *runn;
 245
 246   free (pfile->op_stack);
 247
 248   while (CPP_BUFFER (pfile) != NULL)
 249     _cpp_pop_buffer (pfile);
 250
 251   if (pfile->out.base)
 252     free (pfile->out.base);
 253
 254   if (pfile->macro_buffer)
 255     {
 256       free (pfile->macro_buffer);
 257       pfile->macro_buffer = NULL;
 258       pfile->macro_buffer_len = 0;
 259     }
 260
 261   if (pfile->deps)
 262     deps_free (pfile->deps);
 263   obstack_free (&pfile->buffer_ob, 0);
 264
 265   _cpp_destroy_hashtable (pfile);
 266   _cpp_cleanup_files (pfile);
 267   _cpp_destroy_iconv (pfile);
 268
 269   _cpp_free_buff (pfile->a_buff);
 270   _cpp_free_buff (pfile->u_buff);
 271   _cpp_free_buff (pfile->free_buffs);
 272
 273   for (run = &pfile->base_run; run; run = runn)
 274     {
 275       runn = run->next;
 276       free (run->base);
 277       if (run != &pfile->base_run)
 278         free (run);
 279     }
 280
 281   for (context = pfile->base_context.next; context; context = contextn)
 282     {
 283       contextn = context->next;
 284       free (context);
 285     }
 286
 287   free (pfile);
 288 }
 289
 290 /* This structure defines one built-in identifier.  A node will be
 291    entered in the hash table under the name NAME, with value VALUE.
 292
 293    There are two tables of these.  builtin_array holds all the
 294    "builtin" macros: these are handled by builtin_macro() in
 295    macro.c.  Builtin is somewhat of a misnomer -- the property of
 296    interest is that these macros require special code to compute their
 297    expansions.  The value is a "builtin_type" enumerator.
 298
 299    operator_array holds the C++ named operators.  These are keywords
 300    which act as aliases for punctuators.  In C++, they cannot be
 301    altered through #define, and #if recognizes them as operators.  In
 302    C, these are not entered into the hash table at all (but see
 303    <iso646.h>).  The value is a token-type enumerator.  */
 304 struct builtin
 305 {
 306   const uchar *name;
 307   unsigned short len;
 308   unsigned short value;
 309 };
 310
 311 #define B(n, t)    { DSC(n), t }
 312 static const struct builtin builtin_array[] =
 313 {
 314   B("__TIMESTAMP__",     BT_TIMESTAMP),
 315   B("__TIME__",          BT_TIME),
 316   B("__DATE__",          BT_DATE),
 317   B("__FILE__",          BT_FILE),
 318   B("__BASE_FILE__",     BT_BASE_FILE),
 319   B("__LINE__",          BT_SPECLINE),
 320   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
 321   B("__COUNTER__",       BT_COUNTER),
 322   /* Keep builtins not used for -traditional-cpp at the end, and
 323      update init_builtins() if any more are added.  */
 324   B("_Pragma",           BT_PRAGMA),
 325   B("__STDC__",          BT_STDC),
 326 };
 327
 328 static const struct builtin operator_array[] =
 329 {
 330   B("and",      CPP_AND_AND),
 331   B("and_eq",   CPP_AND_EQ),
 332   B("bitand",   CPP_AND),
 333   B("bitor",    CPP_OR),
 334   B("compl",    CPP_COMPL),
 335   B("not",      CPP_NOT),
 336   B("not_eq",   CPP_NOT_EQ),
 337   B("or",       CPP_OR_OR),
 338   B("or_eq",    CPP_OR_EQ),
 339   B("xor",      CPP_XOR),
 340   B("xor_eq",   CPP_XOR_EQ)
 341 };
 342 #undef B
 343
 344 /* Mark the C++ named operators in the hash table.  */
 345 static void
 346 mark_named_operators (cpp_reader *pfile)
 347 {
 348   const struct builtin *b;
 349
 350   for (b = operator_array;
 351        b < (operator_array + ARRAY_SIZE (operator_array));
 352        b++)
 353     {
 354       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 355       hp->flags |= NODE_OPERATOR;
 356       hp->is_directive = 0;
 357       hp->directive_index = b->value;
 358     }
 359 }
 360
 361 void
 362 cpp_init_special_builtins (cpp_reader *pfile)
 363 {
 364   const struct builtin *b;
 365   size_t n = ARRAY_SIZE (builtin_array);
 366
 367   if (CPP_OPTION (pfile, traditional))
 368     n -= 2;
 369   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 370            || CPP_OPTION (pfile, std))
 371     n--;
 372
 373   for (b = builtin_array; b < builtin_array + n; b++)
 374     {
 375       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 376       hp->type = NT_MACRO;
 377       hp->flags |= NODE_BUILTIN | NODE_WARN;
 378       hp->value.builtin = (enum builtin_type) b->value;
 379     }
 380 }
 381
 382 /* Read the builtins table above and enter them, and language-specific
 383    macros, into the hash table.  HOSTED is true if this is a hosted
 384    environment.  */
 385 void
 386 cpp_init_builtins (cpp_reader *pfile, int hosted)
 387 {
 388   cpp_init_special_builtins (pfile);
 389
 390   if (!CPP_OPTION (pfile, traditional)
 391       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 392           || CPP_OPTION (pfile, std)))
 393     _cpp_define_builtin (pfile, "__STDC__ 1");
 394
 395   if (CPP_OPTION (pfile, cplusplus))
 396     _cpp_define_builtin (pfile, "__cplusplus 1");
 397   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 398     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 399   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 400     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 401   else if (CPP_OPTION (pfile, c99))
 402     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 403
 404   if (hosted)
 405     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 406   else
 407     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 408
 409   if (CPP_OPTION (pfile, objc))
 410     _cpp_define_builtin (pfile, "__OBJC__ 1");
 411 }
 412
 413 /* Sanity-checks are dependent on command-line options, so it is
 414    called as a subroutine of cpp_read_main_file ().  */
 415 #if ENABLE_CHECKING
 416 static void sanity_checks (cpp_reader *);
 417 static void sanity_checks (cpp_reader *pfile)
 418 {
 419   cppchar_t test = 0;
 420   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 421
 422   /* Sanity checks for assumptions about CPP arithmetic and target
 423      type precisions made by cpplib.  */
 424   test--;
 425   if (test < 1)
 426     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 427
 428   if (CPP_OPTION (pfile, precision) > max_precision)
 429     cpp_error (pfile, CPP_DL_ICE,
 430                "preprocessor arithmetic has maximum precision of %lu bits;"
 431                " target requires %lu bits",
 432                (unsigned long) max_precision,
 433                (unsigned long) CPP_OPTION (pfile, precision));
 434
 435   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 436     cpp_error (pfile, CPP_DL_ICE,
 437                "CPP arithmetic must be at least as precise as a target int");
 438
 439   if (CPP_OPTION (pfile, char_precision) < 8)
 440     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 441
 442   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 443     cpp_error (pfile, CPP_DL_ICE,
 444                "target wchar_t is narrower than target char");
 445
 446   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 447     cpp_error (pfile, CPP_DL_ICE,
 448                "target int is narrower than target char");
 449
 450   /* This is assumed in eval_token() and could be fixed if necessary.  */
 451   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 452     cpp_error (pfile, CPP_DL_ICE,
 453                "CPP half-integer narrower than CPP character");
 454
 455   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 456     cpp_error (pfile, CPP_DL_ICE,
 457                "CPP on this host cannot handle wide character constants over"
 458                " %lu bits, but the target requires %lu bits",
 459                (unsigned long) BITS_PER_CPPCHAR_T,
 460                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 461 }
 462 #else
 463 # define sanity_checks(PFILE)
 464 #endif
 465
 466 /* This is called after options have been parsed, and partially
 467    processed.  */
 468 void
 469 cpp_post_options (cpp_reader *pfile)
 470 {
 471   sanity_checks (pfile);
 472
 473   post_options (pfile);
 474
 475   /* Mark named operators before handling command line macros.  */
 476   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 477     mark_named_operators (pfile);
 478 }
 479
 480 /* Setup for processing input from the file named FNAME, or stdin if
 481    it is the empty string.  Return the original filename
 482    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 483 const char *
 484 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 485 {
 486   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 487     {
 488       if (!pfile->deps)
 489         pfile->deps = deps_init ();
 490
 491       /* Set the default target (if there is none already).  */
 492       deps_add_default_target (pfile->deps, fname);
 493     }
 494
 495   pfile->main_file
 496     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0);
 497   if (_cpp_find_failed (pfile->main_file))
 498     return NULL;
 499
 500   _cpp_stack_file (pfile, pfile->main_file, false);
 501
 502   /* For foo.i, read the original filename foo.c now, for the benefit
 503      of the front ends.  */
 504   if (CPP_OPTION (pfile, preprocessed))
 505     {
 506       read_original_filename (pfile);
 507       fname = pfile->line_table->maps[pfile->line_table->used-1].to_file;
 508     }
 509   return fname;
 510 }
 511
 512 /* For preprocessed files, if the first tokens are of the form # NUM.
 513    handle the directive so we know the original file name.  This will
 514    generate file_change callbacks, which the front ends must handle
 515    appropriately given their state of initialization.  */
 516 static void
 517 read_original_filename (cpp_reader *pfile)
 518 {
 519   const cpp_token *token, *token1;
 520
 521   /* Lex ahead; if the first tokens are of the form # NUM, then
 522      process the directive, otherwise back up.  */
 523   token = _cpp_lex_direct (pfile);
 524   if (token->type == CPP_HASH)
 525     {
 526       pfile->state.in_directive = 1;
 527       token1 = _cpp_lex_direct (pfile);
 528       _cpp_backup_tokens (pfile, 1);
 529       pfile->state.in_directive = 0;
 530
 531       /* If it's a #line directive, handle it.  */
 532       if (token1->type == CPP_NUMBER)
 533         {
 534           _cpp_handle_directive (pfile, token->flags & PREV_WHITE);
 535           read_original_directory (pfile);
 536           return;
 537         }
 538     }
 539
 540   /* Backup as if nothing happened.  */
 541   _cpp_backup_tokens (pfile, 1);
 542 }
 543
 544 /* For preprocessed files, if the tokens following the first filename
 545    line is of the form # <line> "/path/name//", handle the
 546    directive so we know the original current directory.  */
 547 static void
 548 read_original_directory (cpp_reader *pfile)
 549 {
 550   const cpp_token *hash, *token;
 551
 552   /* Lex ahead; if the first tokens are of the form # NUM, then
 553      process the directive, otherwise back up.  */
 554   hash = _cpp_lex_direct (pfile);
 555   if (hash->type != CPP_HASH)
 556     {
 557       _cpp_backup_tokens (pfile, 1);
 558       return;
 559     }
 560
 561   token = _cpp_lex_direct (pfile);
 562
 563   if (token->type != CPP_NUMBER)
 564     {
 565       _cpp_backup_tokens (pfile, 2);
 566       return;
 567     }
 568
 569   token = _cpp_lex_direct (pfile);
 570
 571   if (token->type != CPP_STRING
 572       || ! (token->val.str.len >= 5
 573             && token->val.str.text[token->val.str.len-2] == '/'
 574             && token->val.str.text[token->val.str.len-3] == '/'))
 575     {
 576       _cpp_backup_tokens (pfile, 3);
 577       return;
 578     }
 579
 580   if (pfile->cb.dir_change)
 581     {
 582       char *debugdir = (char *) alloca (token->val.str.len - 3);
 583
 584       memcpy (debugdir, (const char *) token->val.str.text + 1,
 585               token->val.str.len - 4);
 586       debugdir[token->val.str.len - 4] = '\0';
 587
 588       pfile->cb.dir_change (pfile, debugdir);
 589     }
 590 }
 591
 592 /* This is called at the end of preprocessing.  It pops the last
 593    buffer and writes dependency output, and returns the number of
 594    errors.
 595
 596    Maybe it should also reset state, such that you could call
 597    cpp_start_read with a new filename to restart processing.  */
 598 int
 599 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 600 {
 601   /* Warn about unused macros before popping the final buffer.  */
 602   if (CPP_OPTION (pfile, warn_unused_macros))
 603     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 604
 605   /* lex.c leaves the final buffer on the stack.  This it so that
 606      it returns an unending stream of CPP_EOFs to the client.  If we
 607      popped the buffer, we'd dereference a NULL buffer pointer and
 608      segfault.  It's nice to allow the client to do worry-free excess
 609      cpp_get_token calls.  */
 610   while (pfile->buffer)
 611     _cpp_pop_buffer (pfile);
 612
 613   /* Don't write the deps file if there are errors.  */
 614   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 615       && deps_stream && pfile->errors == 0)
 616     {
 617       deps_write (pfile->deps, deps_stream, 72);
 618
 619       if (CPP_OPTION (pfile, deps.phony_targets))
 620         deps_phony_targets (pfile->deps, deps_stream);
 621     }
 622
 623   /* Report on headers that could use multiple include guards.  */
 624   if (CPP_OPTION (pfile, print_include_names))
 625     _cpp_report_missing_guards (pfile);
 626
 627   return pfile->errors;
 628 }
 629
 630 static void
 631 post_options (cpp_reader *pfile)
 632 {
 633   /* -Wtraditional is not useful in C++ mode.  */
 634   if (CPP_OPTION (pfile, cplusplus))
 635     CPP_OPTION (pfile, warn_traditional) = 0;
 636
 637   /* Permanently disable macro expansion if we are rescanning
 638      preprocessed text.  Read preprocesed source in ISO mode.  */
 639   if (CPP_OPTION (pfile, preprocessed))
 640     {
 641       if (!CPP_OPTION (pfile, directives_only))
 642         pfile->state.prevent_expansion = 1;
 643       CPP_OPTION (pfile, traditional) = 0;
 644     }
 645
 646   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 647     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 648
 649   if (CPP_OPTION (pfile, traditional))
 650     {
 651       CPP_OPTION (pfile, cplusplus_comments) = 0;
 652
 653       /* Traditional CPP does not accurately track column information.  */
 654       CPP_OPTION (pfile, show_column) = 0;
 655       CPP_OPTION (pfile, trigraphs) = 0;
 656       CPP_OPTION (pfile, warn_trigraphs) = 0;
 657     }
 658 }