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, 2008,
   4    2009, 2010 Free Software Foundation, Inc.
   5    Contributed by Per Bothner, 1994-95.
   6    Based on CCCP program by Paul Rubin, June 1986
   7    Adapted to ANSI C, Richard Stallman, Jan 1987
   8
   9 This program is free software; you can redistribute it and/or modify it
  10 under the terms of the GNU General Public License as published by the
  11 Free Software Foundation; either version 3, or (at your option) any
  12 later version.
  13
  14 This program is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with this program; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "cpplib.h"
  26 #include "internal.h"
  27 #include "mkdeps.h"
  28 #include "localedir.h"
  29
  30 static void init_library (void);
  31 static void mark_named_operators (cpp_reader *, int);
  32 static void read_original_filename (cpp_reader *);
  33 static void read_original_directory (cpp_reader *);
  34 static void post_options (cpp_reader *);
  35
  36 /* If we have designated initializers (GCC >2.7) these tables can be
  37    initialized, constant data.  Otherwise, they have to be filled in at
  38    runtime.  */
  39 #if HAVE_DESIGNATED_INITIALIZERS
  40
  41 #define init_trigraph_map()  /* Nothing.  */
  42 #define TRIGRAPH_MAP \
  43 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
  44
  45 #define END };
  46 #define s(p, v) [p] = v,
  47
  48 #else
  49
  50 #define TRIGRAPH_MAP uchar _cpp_trigraph_map[UCHAR_MAX + 1] = { 0 }; \
  51  static void init_trigraph_map (void) { \
  52  unsigned char *x = _cpp_trigraph_map;
  53
  54 #define END }
  55 #define s(p, v) x[p] = v;
  56
  57 #endif
  58
  59 TRIGRAPH_MAP
  60   s('=', '#')   s(')', ']')     s('!', '|')
  61   s('(', '[')   s('\'', '^')    s('>', '}')
  62   s('/', '\\')  s('<', '{')     s('-', '~')
  63 END
  64
  65 #undef s
  66 #undef END
  67 #undef TRIGRAPH_MAP
  68
  69 /* A set of booleans indicating what CPP features each source language
  70    requires.  */
  71 struct lang_flags
  72 {
  73   char c99;
  74   char cplusplus;
  75   char extended_numbers;
  76   char extended_identifiers;
  77   char std;
  78   char cplusplus_comments;
  79   char digraphs;
  80   char uliterals;
  81 };
  82
  83 static const struct lang_flags lang_defaults[] =
  84 { /*              c99 c++ xnum xid std  //   digr ulit */
  85   /* GNUC89   */  { 0,  0,  1,   0,  0,   1,   1,   0 },
  86   /* GNUC99   */  { 1,  0,  1,   0,  0,   1,   1,   1 },
  87   /* GNUC1X   */  { 1,  0,  1,   0,  0,   1,   1,   1 },
  88   /* STDC89   */  { 0,  0,  0,   0,  1,   0,   0,   0 },
  89   /* STDC94   */  { 0,  0,  0,   0,  1,   0,   1,   0 },
  90   /* STDC99   */  { 1,  0,  1,   0,  1,   1,   1,   0 },
  91   /* STDC1X   */  { 1,  0,  1,   0,  1,   1,   1,   0 },
  92   /* GNUCXX   */  { 0,  1,  1,   0,  0,   1,   1,   0 },
  93   /* CXX98    */  { 0,  1,  1,   0,  1,   1,   1,   0 },
  94   /* GNUCXX0X */  { 1,  1,  1,   0,  0,   1,   1,   1 },
  95   /* CXX0X    */  { 1,  1,  1,   0,  1,   1,   1,   1 },
  96   /* ASM      */  { 0,  0,  1,   0,  0,   1,   0,   0 }
  97   /* xid should be 1 for GNUC99, STDC99, GNUCXX, CXX98, GNUCXX0X, and
  98      CXX0X when no longer experimental (when all uses of identifiers
  99      in the compiler have been audited for correct handling of
 100      extended identifiers).  */
 101 };
 102
 103 /* Sets internal flags correctly for a given language.  */
 104 void
 105 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 106 {
 107   const struct lang_flags *l = &lang_defaults[(int) lang];
 108
 109   CPP_OPTION (pfile, lang) = lang;
 110
 111   CPP_OPTION (pfile, c99)                        = l->c99;
 112   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 113   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 114   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 115   CPP_OPTION (pfile, std)                        = l->std;
 116   CPP_OPTION (pfile, trigraphs)                  = l->std;
 117   CPP_OPTION (pfile, cplusplus_comments)         = l->cplusplus_comments;
 118   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 119   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 120 }
 121
 122 /* Initialize library global state.  */
 123 static void
 124 init_library (void)
 125 {
 126   static int initialized = 0;
 127
 128   if (! initialized)
 129     {
 130       initialized = 1;
 131
 132       /* Set up the trigraph map.  This doesn't need to do anything if
 133          we were compiled with a compiler that supports C99 designated
 134          initializers.  */
 135       init_trigraph_map ();
 136
 137 #ifdef ENABLE_NLS
 138        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 139 #endif
 140     }
 141 }
 142
 143 /* Initialize a cpp_reader structure.  */
 144 cpp_reader *
 145 cpp_create_reader (enum c_lang lang, hash_table *table,
 146                    struct line_maps *line_table)
 147 {
 148   cpp_reader *pfile;
 149
 150   /* Initialize this instance of the library if it hasn't been already.  */
 151   init_library ();
 152
 153   pfile = XCNEW (cpp_reader);
 154
 155   cpp_set_lang (pfile, lang);
 156   CPP_OPTION (pfile, warn_multichar) = 1;
 157   CPP_OPTION (pfile, discard_comments) = 1;
 158   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 159   CPP_OPTION (pfile, tabstop) = 8;
 160   CPP_OPTION (pfile, operator_names) = 1;
 161   CPP_OPTION (pfile, warn_trigraphs) = 2;
 162   CPP_OPTION (pfile, warn_endif_labels) = 1;
 163   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 164   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 165   CPP_OPTION (pfile, dollars_in_ident) = 1;
 166   CPP_OPTION (pfile, warn_dollars) = 1;
 167   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 168   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 169   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 170
 171   /* Default CPP arithmetic to something sensible for the host for the
 172      benefit of dumb users like fix-header.  */
 173   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 174   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 175   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 176   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 177   CPP_OPTION (pfile, unsigned_char) = 0;
 178   CPP_OPTION (pfile, unsigned_wchar) = 1;
 179   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 180
 181   /* Default to no charset conversion.  */
 182   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 183   CPP_OPTION (pfile, wide_charset) = 0;
 184
 185   /* Default the input character set to UTF-8.  */
 186   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 187
 188   /* A fake empty "directory" used as the starting point for files
 189      looked up without a search path.  Name cannot be '/' because we
 190      don't want to prepend anything at all to filenames using it.  All
 191      other entries are correct zero-initialized.  */
 192   pfile->no_search_path.name = (char *) "";
 193
 194   /* Initialize the line map.  */
 195   pfile->line_table = line_table;
 196
 197   /* Initialize lexer state.  */
 198   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 199
 200   /* Set up static tokens.  */
 201   pfile->avoid_paste.type = CPP_PADDING;
 202   pfile->avoid_paste.val.source = NULL;
 203   pfile->eof.type = CPP_EOF;
 204   pfile->eof.flags = 0;
 205
 206   /* Create a token buffer for the lexer.  */
 207   _cpp_init_tokenrun (&pfile->base_run, 250);
 208   pfile->cur_run = &pfile->base_run;
 209   pfile->cur_token = pfile->base_run.base;
 210
 211   /* Initialize the base context.  */
 212   pfile->context = &pfile->base_context;
 213   pfile->base_context.macro = 0;
 214   pfile->base_context.prev = pfile->base_context.next = 0;
 215
 216   /* Aligned and unaligned storage.  */
 217   pfile->a_buff = _cpp_get_buff (pfile, 0);
 218   pfile->u_buff = _cpp_get_buff (pfile, 0);
 219
 220   /* Initialize table for push_macro/pop_macro.  */
 221   pfile->pushed_macros = 0;
 222
 223   /* The expression parser stack.  */
 224   _cpp_expand_op_stack (pfile);
 225
 226   /* Initialize the buffer obstack.  */
 227   _obstack_begin (&pfile->buffer_ob, 0, 0,
 228                   (void *(*) (long)) xmalloc,
 229                   (void (*) (void *)) free);
 230
 231   _cpp_init_files (pfile);
 232
 233   _cpp_init_hashtable (pfile, table);
 234   pfile->lookaside_table = NULL;
 235
 236   return pfile;
 237 }
 238
 239
 240 /* Set the line_table entry in PFILE.  This is called after reading a
 241    PCH file, as the old line_table will be incorrect.  */
 242 void
 243 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 244 {
 245   pfile->line_table = line_table;
 246 }
 247
 248 /* Free resources used by PFILE.  Accessing PFILE after this function
 249    returns leads to undefined behavior.  Returns the error count.  */
 250 void
 251 cpp_destroy (cpp_reader *pfile)
 252 {
 253   cpp_context *context, *contextn;
 254   struct def_pragma_macro *pmacro;
 255   tokenrun *run, *runn;
 256   int i;
 257
 258   free (pfile->op_stack);
 259
 260   while (CPP_BUFFER (pfile) != NULL)
 261     _cpp_pop_buffer (pfile);
 262
 263   if (pfile->out.base)
 264     free (pfile->out.base);
 265
 266   if (pfile->macro_buffer)
 267     {
 268       free (pfile->macro_buffer);
 269       pfile->macro_buffer = NULL;
 270       pfile->macro_buffer_len = 0;
 271     }
 272
 273   if (pfile->param_buffer)
 274     {
 275       free (pfile->param_buffer);
 276       pfile->param_buffer = NULL;
 277       pfile->param_buffer_len = 0;
 278     }
 279
 280   if (pfile->deps)
 281     deps_free (pfile->deps);
 282   obstack_free (&pfile->buffer_ob, 0);
 283
 284   _cpp_destroy_hashtable (pfile);
 285   _cpp_cleanup_files (pfile);
 286   _cpp_destroy_iconv (pfile);
 287
 288   _cpp_free_buff (pfile->a_buff);
 289   _cpp_free_buff (pfile->u_buff);
 290   _cpp_free_buff (pfile->free_buffs);
 291
 292   for (run = &pfile->base_run; run; run = runn)
 293     {
 294       runn = run->next;
 295       free (run->base);
 296       if (run != &pfile->base_run)
 297         free (run);
 298     }
 299
 300   for (context = pfile->base_context.next; context; context = contextn)
 301     {
 302       contextn = context->next;
 303       free (context);
 304     }
 305
 306   if (pfile->comments.entries)
 307     {
 308       for (i = 0; i < pfile->comments.count; i++)
 309         free (pfile->comments.entries[i].comment);
 310
 311       free (pfile->comments.entries);
 312     }
 313   if (pfile->pushed_macros)
 314     {
 315       do
 316         {
 317           pmacro = pfile->pushed_macros;
 318           pfile->pushed_macros = pmacro->next;
 319           free (pmacro->name);
 320           free (pmacro);
 321         }
 322       while (pfile->pushed_macros);
 323     }
 324
 325   if (pfile->lookaside_table)
 326     cpp_lt_destroy (pfile->lookaside_table);
 327
 328   free (pfile);
 329 }
 330
 331 /* This structure defines one built-in identifier.  A node will be
 332    entered in the hash table under the name NAME, with value VALUE.
 333
 334    There are two tables of these.  builtin_array holds all the
 335    "builtin" macros: these are handled by builtin_macro() in
 336    macro.c.  Builtin is somewhat of a misnomer -- the property of
 337    interest is that these macros require special code to compute their
 338    expansions.  The value is a "cpp_builtin_type" enumerator.
 339
 340    operator_array holds the C++ named operators.  These are keywords
 341    which act as aliases for punctuators.  In C++, they cannot be
 342    altered through #define, and #if recognizes them as operators.  In
 343    C, these are not entered into the hash table at all (but see
 344    <iso646.h>).  The value is a token-type enumerator.  */
 345 struct builtin_macro
 346 {
 347   const uchar *const name;
 348   const unsigned short len;
 349   const unsigned short value;
 350   const bool always_warn_if_redefined;
 351 };
 352
 353 #define B(n, t, f)    { DSC(n), t, f }
 354 static const struct builtin_macro builtin_array[] =
 355 {
 356   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 357   B("__TIME__",          BT_TIME,          false),
 358   B("__DATE__",          BT_DATE,          false),
 359   B("__FILE__",          BT_FILE,          false),
 360   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 361   B("__LINE__",          BT_SPECLINE,      true),
 362   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 363   B("__COUNTER__",       BT_COUNTER,       true),
 364   /* Keep builtins not used for -traditional-cpp at the end, and
 365      update init_builtins() if any more are added.  */
 366   B("_Pragma",           BT_PRAGMA,        true),
 367   B("__STDC__",          BT_STDC,          true),
 368 };
 369 #undef B
 370
 371 struct builtin_operator
 372 {
 373   const uchar *const name;
 374   const unsigned short len;
 375   const unsigned short value;
 376 };
 377
 378 #define B(n, t)    { DSC(n), t }
 379 static const struct builtin_operator operator_array[] =
 380 {
 381   B("and",      CPP_AND_AND),
 382   B("and_eq",   CPP_AND_EQ),
 383   B("bitand",   CPP_AND),
 384   B("bitor",    CPP_OR),
 385   B("compl",    CPP_COMPL),
 386   B("not",      CPP_NOT),
 387   B("not_eq",   CPP_NOT_EQ),
 388   B("or",       CPP_OR_OR),
 389   B("or_eq",    CPP_OR_EQ),
 390   B("xor",      CPP_XOR),
 391   B("xor_eq",   CPP_XOR_EQ)
 392 };
 393 #undef B
 394
 395 /* Mark the C++ named operators in the hash table.  */
 396 static void
 397 mark_named_operators (cpp_reader *pfile, int flags)
 398 {
 399   const struct builtin_operator *b;
 400
 401   for (b = operator_array;
 402        b < (operator_array + ARRAY_SIZE (operator_array));
 403        b++)
 404     {
 405       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 406       hp->flags |= flags;
 407       hp->is_directive = 0;
 408       hp->directive_index = b->value;
 409     }
 410 }
 411
 412 /* Helper function of cpp_type2name. Return the string associated with
 413    named operator TYPE.  */
 414 const char *
 415 cpp_named_operator2name (enum cpp_ttype type)
 416 {
 417   const struct builtin_operator *b;
 418
 419   for (b = operator_array;
 420        b < (operator_array + ARRAY_SIZE (operator_array));
 421        b++)
 422     {
 423       if (type == b->value)
 424         return (const char *) b->name;
 425     }
 426
 427   return NULL;
 428 }
 429
 430 void
 431 cpp_init_special_builtins (cpp_reader *pfile)
 432 {
 433   const struct builtin_macro *b;
 434   size_t n = ARRAY_SIZE (builtin_array);
 435
 436   if (CPP_OPTION (pfile, traditional))
 437     n -= 2;
 438   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 439            || CPP_OPTION (pfile, std))
 440     n--;
 441
 442   for (b = builtin_array; b < builtin_array + n; b++)
 443     {
 444       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 445       hp->type = NT_MACRO;
 446       hp->flags |= NODE_BUILTIN;
 447       if (b->always_warn_if_redefined
 448           || CPP_OPTION (pfile, warn_builtin_macro_redefined))
 449         hp->flags |= NODE_WARN;
 450       hp->value.builtin = (enum cpp_builtin_type) b->value;
 451     }
 452 }
 453
 454 /* Read the builtins table above and enter them, and language-specific
 455    macros, into the hash table.  HOSTED is true if this is a hosted
 456    environment.  */
 457 void
 458 cpp_init_builtins (cpp_reader *pfile, int hosted)
 459 {
 460   cpp_init_special_builtins (pfile);
 461
 462   if (!CPP_OPTION (pfile, traditional)
 463       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 464           || CPP_OPTION (pfile, std)))
 465     _cpp_define_builtin (pfile, "__STDC__ 1");
 466
 467   if (CPP_OPTION (pfile, cplusplus))
 468     _cpp_define_builtin (pfile, "__cplusplus 1");
 469   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 470     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 471   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 472     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 473   else if (CPP_OPTION (pfile, lang) == CLK_STDC1X
 474            || CPP_OPTION (pfile, lang) == CLK_GNUC1X)
 475     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201000L");
 476   else if (CPP_OPTION (pfile, c99))
 477     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 478
 479   if (hosted)
 480     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 481   else
 482     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 483
 484   if (CPP_OPTION (pfile, objc))
 485     _cpp_define_builtin (pfile, "__OBJC__ 1");
 486 }
 487
 488 /* Sanity-checks are dependent on command-line options, so it is
 489    called as a subroutine of cpp_read_main_file ().  */
 490 #if ENABLE_CHECKING
 491 static void sanity_checks (cpp_reader *);
 492 static void sanity_checks (cpp_reader *pfile)
 493 {
 494   cppchar_t test = 0;
 495   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 496
 497   /* Sanity checks for assumptions about CPP arithmetic and target
 498      type precisions made by cpplib.  */
 499   test--;
 500   if (test < 1)
 501     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 502
 503   if (CPP_OPTION (pfile, precision) > max_precision)
 504     cpp_error (pfile, CPP_DL_ICE,
 505                "preprocessor arithmetic has maximum precision of %lu bits;"
 506                " target requires %lu bits",
 507                (unsigned long) max_precision,
 508                (unsigned long) CPP_OPTION (pfile, precision));
 509
 510   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 511     cpp_error (pfile, CPP_DL_ICE,
 512                "CPP arithmetic must be at least as precise as a target int");
 513
 514   if (CPP_OPTION (pfile, char_precision) < 8)
 515     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 516
 517   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 518     cpp_error (pfile, CPP_DL_ICE,
 519                "target wchar_t is narrower than target char");
 520
 521   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 522     cpp_error (pfile, CPP_DL_ICE,
 523                "target int is narrower than target char");
 524
 525   /* This is assumed in eval_token() and could be fixed if necessary.  */
 526   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 527     cpp_error (pfile, CPP_DL_ICE,
 528                "CPP half-integer narrower than CPP character");
 529
 530   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 531     cpp_error (pfile, CPP_DL_ICE,
 532                "CPP on this host cannot handle wide character constants over"
 533                " %lu bits, but the target requires %lu bits",
 534                (unsigned long) BITS_PER_CPPCHAR_T,
 535                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 536 }
 537 #else
 538 # define sanity_checks(PFILE)
 539 #endif
 540
 541 /* This is called after options have been parsed, and partially
 542    processed.  */
 543 void
 544 cpp_post_options (cpp_reader *pfile)
 545 {
 546   int flags;
 547
 548   sanity_checks (pfile);
 549
 550   post_options (pfile);
 551
 552   /* Mark named operators before handling command line macros.  */
 553   flags = 0;
 554   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 555     flags |= NODE_OPERATOR;
 556   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 557     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 558   if (flags != 0)
 559     mark_named_operators (pfile, flags);
 560 }
 561
 562 /* Setup for processing input from the file named FNAME, or stdin if
 563    it is the empty string.  Return the original filename
 564    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 565 const char *
 566 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 567 {
 568   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 569     {
 570       if (!pfile->deps)
 571         pfile->deps = deps_init ();
 572
 573       /* Set the default target (if there is none already).  */
 574       deps_add_default_target (pfile->deps, fname);
 575     }
 576
 577   pfile->main_file
 578     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0);
 579   if (_cpp_find_failed (pfile->main_file))
 580     return NULL;
 581
 582   _cpp_stack_file (pfile, pfile->main_file, false);
 583
 584   /* For foo.i, read the original filename foo.c now, for the benefit
 585      of the front ends.  */
 586   if (CPP_OPTION (pfile, preprocessed))
 587     {
 588       read_original_filename (pfile);
 589       fname = pfile->line_table->maps[pfile->line_table->used-1].to_file;
 590     }
 591   return fname;
 592 }
 593
 594 /* For preprocessed files, if the first tokens are of the form # NUM.
 595    handle the directive so we know the original file name.  This will
 596    generate file_change callbacks, which the front ends must handle
 597    appropriately given their state of initialization.  */
 598 static void
 599 read_original_filename (cpp_reader *pfile)
 600 {
 601   const cpp_token *token, *token1;
 602
 603   /* Lex ahead; if the first tokens are of the form # NUM, then
 604      process the directive, otherwise back up.  */
 605   token = _cpp_lex_direct (pfile);
 606   if (token->type == CPP_HASH)
 607     {
 608       pfile->state.in_directive = 1;
 609       token1 = _cpp_lex_direct (pfile);
 610       _cpp_backup_tokens (pfile, 1);
 611       pfile->state.in_directive = 0;
 612
 613       /* If it's a #line directive, handle it.  */
 614       if (token1->type == CPP_NUMBER
 615           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 616         {
 617           read_original_directory (pfile);
 618           return;
 619         }
 620     }
 621
 622   /* Backup as if nothing happened.  */
 623   _cpp_backup_tokens (pfile, 1);
 624 }
 625
 626 /* For preprocessed files, if the tokens following the first filename
 627    line is of the form # <line> "/path/name//", handle the
 628    directive so we know the original current directory.  */
 629 static void
 630 read_original_directory (cpp_reader *pfile)
 631 {
 632   const cpp_token *hash, *token;
 633
 634   /* Lex ahead; if the first tokens are of the form # NUM, then
 635      process the directive, otherwise back up.  */
 636   hash = _cpp_lex_direct (pfile);
 637   if (hash->type != CPP_HASH)
 638     {
 639       _cpp_backup_tokens (pfile, 1);
 640       return;
 641     }
 642
 643   token = _cpp_lex_direct (pfile);
 644
 645   if (token->type != CPP_NUMBER)
 646     {
 647       _cpp_backup_tokens (pfile, 2);
 648       return;
 649     }
 650
 651   token = _cpp_lex_direct (pfile);
 652
 653   if (token->type != CPP_STRING
 654       || ! (token->val.str.len >= 5
 655             && token->val.str.text[token->val.str.len-2] == '/'
 656             && token->val.str.text[token->val.str.len-3] == '/'))
 657     {
 658       _cpp_backup_tokens (pfile, 3);
 659       return;
 660     }
 661
 662   if (pfile->cb.dir_change)
 663     {
 664       char *debugdir = (char *) alloca (token->val.str.len - 3);
 665
 666       memcpy (debugdir, (const char *) token->val.str.text + 1,
 667               token->val.str.len - 4);
 668       debugdir[token->val.str.len - 4] = '\0';
 669
 670       pfile->cb.dir_change (pfile, debugdir);
 671     }
 672 }
 673
 674 /* This is called at the end of preprocessing.  It pops the last
 675    buffer and writes dependency output.
 676
 677    Maybe it should also reset state, such that you could call
 678    cpp_start_read with a new filename to restart processing.  */
 679 void
 680 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 681 {
 682   /* Warn about unused macros before popping the final buffer.  */
 683   if (CPP_OPTION (pfile, warn_unused_macros))
 684     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 685
 686   /* lex.c leaves the final buffer on the stack.  This it so that
 687      it returns an unending stream of CPP_EOFs to the client.  If we
 688      popped the buffer, we'd dereference a NULL buffer pointer and
 689      segfault.  It's nice to allow the client to do worry-free excess
 690      cpp_get_token calls.  */
 691   while (pfile->buffer)
 692     _cpp_pop_buffer (pfile);
 693
 694   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 695       && deps_stream)
 696     {
 697       deps_write (pfile->deps, deps_stream, 72);
 698
 699       if (CPP_OPTION (pfile, deps.phony_targets))
 700         deps_phony_targets (pfile->deps, deps_stream);
 701     }
 702
 703   /* Report on headers that could use multiple include guards.  */
 704   if (CPP_OPTION (pfile, print_include_names))
 705     _cpp_report_missing_guards (pfile);
 706 }
 707
 708 static void
 709 post_options (cpp_reader *pfile)
 710 {
 711   /* -Wtraditional is not useful in C++ mode.  */
 712   if (CPP_OPTION (pfile, cplusplus))
 713     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 714
 715   /* Permanently disable macro expansion if we are rescanning
 716      preprocessed text.  Read preprocesed source in ISO mode.  */
 717   if (CPP_OPTION (pfile, preprocessed))
 718     {
 719       if (!CPP_OPTION (pfile, directives_only))
 720         pfile->state.prevent_expansion = 1;
 721       CPP_OPTION (pfile, traditional) = 0;
 722     }
 723
 724   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 725     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 726
 727   if (CPP_OPTION (pfile, traditional))
 728     {
 729       CPP_OPTION (pfile, cplusplus_comments) = 0;
 730
 731       CPP_OPTION (pfile, trigraphs) = 0;
 732       CPP_OPTION (pfile, warn_trigraphs) = 0;
 733     }
 734 }