libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2013 Free Software Foundation, Inc.
   3    Contributed by Per Bothner, 1994-95.
   4    Based on CCCP program by Paul Rubin, June 1986
   5    Adapted to ANSI C, Richard Stallman, Jan 1987
   6
   7 This program is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by the
   9 Free Software Foundation; either version 3, or (at your option) any
  10 later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "cpplib.h"
  24 #include "internal.h"
  25 #include "mkdeps.h"
  26 #include "localedir.h"
  27 #include "filenames.h"
  28
  29 #ifndef ENABLE_CANONICAL_SYSTEM_HEADERS
  30 #define ENABLE_CANONICAL_SYSTEM_HEADERS 0
  31 #endif
  32
  33 static void init_library (void);
  34 static void mark_named_operators (cpp_reader *, int);
  35 static void read_original_filename (cpp_reader *);
  36 static void read_original_directory (cpp_reader *);
  37 static void post_options (cpp_reader *);
  38
  39 /* If we have designated initializers (GCC >2.7) these tables can be
  40    initialized, constant data.  Otherwise, they have to be filled in at
  41    runtime.  */
  42 #if HAVE_DESIGNATED_INITIALIZERS
  43
  44 #define init_trigraph_map()  /* Nothing.  */
  45 #define TRIGRAPH_MAP \
  46 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
  47
  48 #define END };
  49 #define s(p, v) [p] = v,
  50
  51 #else
  52
  53 #define TRIGRAPH_MAP uchar _cpp_trigraph_map[UCHAR_MAX + 1] = { 0 }; \
  54  static void init_trigraph_map (void) { \
  55  unsigned char *x = _cpp_trigraph_map;
  56
  57 #define END }
  58 #define s(p, v) x[p] = v;
  59
  60 #endif
  61
  62 TRIGRAPH_MAP
  63   s('=', '#')   s(')', ']')     s('!', '|')
  64   s('(', '[')   s('\'', '^')    s('>', '}')
  65   s('/', '\\')  s('<', '{')     s('-', '~')
  66 END
  67
  68 #undef s
  69 #undef END
  70 #undef TRIGRAPH_MAP
  71
  72 /* A set of booleans indicating what CPP features each source language
  73    requires.  */
  74 struct lang_flags
  75 {
  76   char c99;
  77   char cplusplus;
  78   char extended_numbers;
  79   char extended_identifiers;
  80   char std;
  81   char cplusplus_comments;
  82   char digraphs;
  83   char uliterals;
  84   char rliterals;
  85   char user_literals;
  86 };
  87
  88 static const struct lang_flags lang_defaults[] =
  89 { /*              c99 c++ xnum xid std  //   digr ulit rlit user_literals */
  90   /* GNUC89   */  { 0,  0,  1,   0,  0,   1,   1,   0,   0,    0 },
  91   /* GNUC99   */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,    0 },
  92   /* GNUC11   */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,    0 },
  93   /* STDC89   */  { 0,  0,  0,   0,  1,   0,   0,   0,   0,    0 },
  94   /* STDC94   */  { 0,  0,  0,   0,  1,   0,   1,   0,   0,    0 },
  95   /* STDC99   */  { 1,  0,  1,   0,  1,   1,   1,   0,   0,    0 },
  96   /* STDC11   */  { 1,  0,  1,   0,  1,   1,   1,   1,   0,    0 },
  97   /* GNUCXX   */  { 0,  1,  1,   0,  0,   1,   1,   0,   0,    0 },
  98   /* CXX98    */  { 0,  1,  1,   0,  1,   1,   1,   0,   0,    0 },
  99   /* GNUCXX11 */  { 1,  1,  1,   0,  0,   1,   1,   1,   1,    1 },
 100   /* CXX11    */  { 1,  1,  1,   0,  1,   1,   1,   1,   1,    1 },
 101   /* ASM      */  { 0,  0,  1,   0,  0,   1,   0,   0,   0,    0 }
 102   /* xid should be 1 for GNUC99, STDC99, GNUCXX, CXX98, GNUCXX11, and
 103      CXX11 when no longer experimental (when all uses of identifiers
 104      in the compiler have been audited for correct handling of
 105      extended identifiers).  */
 106 };
 107
 108 /* Sets internal flags correctly for a given language.  */
 109 void
 110 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 111 {
 112   const struct lang_flags *l = &lang_defaults[(int) lang];
 113
 114   CPP_OPTION (pfile, lang) = lang;
 115
 116   CPP_OPTION (pfile, c99)                        = l->c99;
 117   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 118   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 119   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 120   CPP_OPTION (pfile, std)                        = l->std;
 121   CPP_OPTION (pfile, trigraphs)                  = l->std;
 122   CPP_OPTION (pfile, cplusplus_comments)         = l->cplusplus_comments;
 123   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 124   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 125   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 126   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 127 }
 128
 129 /* Initialize library global state.  */
 130 static void
 131 init_library (void)
 132 {
 133   static int initialized = 0;
 134
 135   if (! initialized)
 136     {
 137       initialized = 1;
 138
 139       _cpp_init_lexer ();
 140
 141       /* Set up the trigraph map.  This doesn't need to do anything if
 142          we were compiled with a compiler that supports C99 designated
 143          initializers.  */
 144       init_trigraph_map ();
 145
 146 #ifdef ENABLE_NLS
 147        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 148 #endif
 149     }
 150 }
 151
 152 /* Initialize a cpp_reader structure.  */
 153 cpp_reader *
 154 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 155                    struct line_maps *line_table)
 156 {
 157   cpp_reader *pfile;
 158
 159   /* Initialize this instance of the library if it hasn't been already.  */
 160   init_library ();
 161
 162   pfile = XCNEW (cpp_reader);
 163   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 164
 165   cpp_set_lang (pfile, lang);
 166   CPP_OPTION (pfile, warn_multichar) = 1;
 167   CPP_OPTION (pfile, discard_comments) = 1;
 168   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 169   CPP_OPTION (pfile, tabstop) = 8;
 170   CPP_OPTION (pfile, operator_names) = 1;
 171   CPP_OPTION (pfile, warn_trigraphs) = 2;
 172   CPP_OPTION (pfile, warn_endif_labels) = 1;
 173   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 174   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 175   CPP_OPTION (pfile, dollars_in_ident) = 1;
 176   CPP_OPTION (pfile, warn_dollars) = 1;
 177   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 178   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 179   /* By default, track locations of tokens resulting from macro
 180      expansion.  The '2' means, track the locations with the highest
 181      accuracy.  Read the comments for struct
 182      cpp_options::track_macro_expansion to learn about the other
 183      values.  */
 184   CPP_OPTION (pfile, track_macro_expansion) = 2;
 185   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 186   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 187   CPP_OPTION (pfile, canonical_system_headers)
 188       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 189   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 190
 191   /* Default CPP arithmetic to something sensible for the host for the
 192      benefit of dumb users like fix-header.  */
 193   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 194   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 195   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 196   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 197   CPP_OPTION (pfile, unsigned_char) = 0;
 198   CPP_OPTION (pfile, unsigned_wchar) = 1;
 199   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 200
 201   /* Default to no charset conversion.  */
 202   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 203   CPP_OPTION (pfile, wide_charset) = 0;
 204
 205   /* Default the input character set to UTF-8.  */
 206   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 207
 208   /* A fake empty "directory" used as the starting point for files
 209      looked up without a search path.  Name cannot be '/' because we
 210      don't want to prepend anything at all to filenames using it.  All
 211      other entries are correct zero-initialized.  */
 212   pfile->no_search_path.name = (char *) "";
 213
 214   /* Initialize the line map.  */
 215   pfile->line_table = line_table;
 216
 217   /* Initialize lexer state.  */
 218   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 219
 220   /* Set up static tokens.  */
 221   pfile->avoid_paste.type = CPP_PADDING;
 222   pfile->avoid_paste.val.source = NULL;
 223   pfile->eof.type = CPP_EOF;
 224   pfile->eof.flags = 0;
 225
 226   /* Create a token buffer for the lexer.  */
 227   _cpp_init_tokenrun (&pfile->base_run, 250);
 228   pfile->cur_run = &pfile->base_run;
 229   pfile->cur_token = pfile->base_run.base;
 230
 231   /* Initialize the base context.  */
 232   pfile->context = &pfile->base_context;
 233   pfile->base_context.c.macro = 0;
 234   pfile->base_context.prev = pfile->base_context.next = 0;
 235
 236   /* Aligned and unaligned storage.  */
 237   pfile->a_buff = _cpp_get_buff (pfile, 0);
 238   pfile->u_buff = _cpp_get_buff (pfile, 0);
 239
 240   /* Initialize table for push_macro/pop_macro.  */
 241   pfile->pushed_macros = 0;
 242
 243   /* Do not force token locations by default.  */
 244   pfile->forced_token_location_p = NULL;
 245
 246   /* The expression parser stack.  */
 247   _cpp_expand_op_stack (pfile);
 248
 249   /* Initialize the buffer obstack.  */
 250   _obstack_begin (&pfile->buffer_ob, 0, 0,
 251                   (void *(*) (long)) xmalloc,
 252                   (void (*) (void *)) free);
 253
 254   _cpp_init_files (pfile);
 255
 256   _cpp_init_hashtable (pfile, table);
 257
 258   return pfile;
 259 }
 260
 261 /* Set the line_table entry in PFILE.  This is called after reading a
 262    PCH file, as the old line_table will be incorrect.  */
 263 void
 264 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 265 {
 266   pfile->line_table = line_table;
 267 }
 268
 269 /* Free resources used by PFILE.  Accessing PFILE after this function
 270    returns leads to undefined behavior.  Returns the error count.  */
 271 void
 272 cpp_destroy (cpp_reader *pfile)
 273 {
 274   cpp_context *context, *contextn;
 275   struct def_pragma_macro *pmacro;
 276   tokenrun *run, *runn;
 277   int i;
 278
 279   free (pfile->op_stack);
 280
 281   while (CPP_BUFFER (pfile) != NULL)
 282     _cpp_pop_buffer (pfile);
 283
 284   free (pfile->out.base);
 285
 286   if (pfile->macro_buffer)
 287     {
 288       free (pfile->macro_buffer);
 289       pfile->macro_buffer = NULL;
 290       pfile->macro_buffer_len = 0;
 291     }
 292
 293   if (pfile->deps)
 294     deps_free (pfile->deps);
 295   obstack_free (&pfile->buffer_ob, 0);
 296
 297   _cpp_destroy_hashtable (pfile);
 298   _cpp_cleanup_files (pfile);
 299   _cpp_destroy_iconv (pfile);
 300
 301   _cpp_free_buff (pfile->a_buff);
 302   _cpp_free_buff (pfile->u_buff);
 303   _cpp_free_buff (pfile->free_buffs);
 304
 305   for (run = &pfile->base_run; run; run = runn)
 306     {
 307       runn = run->next;
 308       free (run->base);
 309       if (run != &pfile->base_run)
 310         free (run);
 311     }
 312
 313   for (context = pfile->base_context.next; context; context = contextn)
 314     {
 315       contextn = context->next;
 316       free (context);
 317     }
 318
 319   if (pfile->comments.entries)
 320     {
 321       for (i = 0; i < pfile->comments.count; i++)
 322         free (pfile->comments.entries[i].comment);
 323
 324       free (pfile->comments.entries);
 325     }
 326   if (pfile->pushed_macros)
 327     {
 328       do
 329         {
 330           pmacro = pfile->pushed_macros;
 331           pfile->pushed_macros = pmacro->next;
 332           free (pmacro->name);
 333           free (pmacro);
 334         }
 335       while (pfile->pushed_macros);
 336     }
 337
 338   free (pfile);
 339 }
 340
 341 /* This structure defines one built-in identifier.  A node will be
 342    entered in the hash table under the name NAME, with value VALUE.
 343
 344    There are two tables of these.  builtin_array holds all the
 345    "builtin" macros: these are handled by builtin_macro() in
 346    macro.c.  Builtin is somewhat of a misnomer -- the property of
 347    interest is that these macros require special code to compute their
 348    expansions.  The value is a "cpp_builtin_type" enumerator.
 349
 350    operator_array holds the C++ named operators.  These are keywords
 351    which act as aliases for punctuators.  In C++, they cannot be
 352    altered through #define, and #if recognizes them as operators.  In
 353    C, these are not entered into the hash table at all (but see
 354    <iso646.h>).  The value is a token-type enumerator.  */
 355 struct builtin_macro
 356 {
 357   const uchar *const name;
 358   const unsigned short len;
 359   const unsigned short value;
 360   const bool always_warn_if_redefined;
 361 };
 362
 363 #define B(n, t, f)    { DSC(n), t, f }
 364 static const struct builtin_macro builtin_array[] =
 365 {
 366   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 367   B("__TIME__",          BT_TIME,          false),
 368   B("__DATE__",          BT_DATE,          false),
 369   B("__FILE__",          BT_FILE,          false),
 370   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 371   B("__LINE__",          BT_SPECLINE,      true),
 372   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 373   B("__COUNTER__",       BT_COUNTER,       true),
 374   /* Keep builtins not used for -traditional-cpp at the end, and
 375      update init_builtins() if any more are added.  */
 376   B("_Pragma",           BT_PRAGMA,        true),
 377   B("__STDC__",          BT_STDC,          true),
 378 };
 379 #undef B
 380
 381 struct builtin_operator
 382 {
 383   const uchar *const name;
 384   const unsigned short len;
 385   const unsigned short value;
 386 };
 387
 388 #define B(n, t)    { DSC(n), t }
 389 static const struct builtin_operator operator_array[] =
 390 {
 391   B("and",      CPP_AND_AND),
 392   B("and_eq",   CPP_AND_EQ),
 393   B("bitand",   CPP_AND),
 394   B("bitor",    CPP_OR),
 395   B("compl",    CPP_COMPL),
 396   B("not",      CPP_NOT),
 397   B("not_eq",   CPP_NOT_EQ),
 398   B("or",       CPP_OR_OR),
 399   B("or_eq",    CPP_OR_EQ),
 400   B("xor",      CPP_XOR),
 401   B("xor_eq",   CPP_XOR_EQ)
 402 };
 403 #undef B
 404
 405 /* Mark the C++ named operators in the hash table.  */
 406 static void
 407 mark_named_operators (cpp_reader *pfile, int flags)
 408 {
 409   const struct builtin_operator *b;
 410
 411   for (b = operator_array;
 412        b < (operator_array + ARRAY_SIZE (operator_array));
 413        b++)
 414     {
 415       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 416       hp->flags |= flags;
 417       hp->is_directive = 0;
 418       hp->directive_index = b->value;
 419     }
 420 }
 421
 422 /* Helper function of cpp_type2name. Return the string associated with
 423    named operator TYPE.  */
 424 const char *
 425 cpp_named_operator2name (enum cpp_ttype type)
 426 {
 427   const struct builtin_operator *b;
 428
 429   for (b = operator_array;
 430        b < (operator_array + ARRAY_SIZE (operator_array));
 431        b++)
 432     {
 433       if (type == b->value)
 434         return (const char *) b->name;
 435     }
 436
 437   return NULL;
 438 }
 439
 440 void
 441 cpp_init_special_builtins (cpp_reader *pfile)
 442 {
 443   const struct builtin_macro *b;
 444   size_t n = ARRAY_SIZE (builtin_array);
 445
 446   if (CPP_OPTION (pfile, traditional))
 447     n -= 2;
 448   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 449            || CPP_OPTION (pfile, std))
 450     n--;
 451
 452   for (b = builtin_array; b < builtin_array + n; b++)
 453     {
 454       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 455       hp->type = NT_MACRO;
 456       hp->flags |= NODE_BUILTIN;
 457       if (b->always_warn_if_redefined
 458           || CPP_OPTION (pfile, warn_builtin_macro_redefined))
 459         hp->flags |= NODE_WARN;
 460       hp->value.builtin = (enum cpp_builtin_type) b->value;
 461     }
 462 }
 463
 464 /* Read the builtins table above and enter them, and language-specific
 465    macros, into the hash table.  HOSTED is true if this is a hosted
 466    environment.  */
 467 void
 468 cpp_init_builtins (cpp_reader *pfile, int hosted)
 469 {
 470   cpp_init_special_builtins (pfile);
 471
 472   if (!CPP_OPTION (pfile, traditional)
 473       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 474           || CPP_OPTION (pfile, std)))
 475     _cpp_define_builtin (pfile, "__STDC__ 1");
 476
 477   if (CPP_OPTION (pfile, cplusplus))
 478     {
 479       if (CPP_OPTION (pfile, lang) == CLK_CXX11
 480            || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 481         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 482       else
 483         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 484     }
 485   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 486     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 487   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 488     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 489   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 490            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 491     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 492   else if (CPP_OPTION (pfile, c99))
 493     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 494
 495   if (CPP_OPTION (pfile, uliterals)
 496       && !CPP_OPTION (pfile, cplusplus))
 497     {
 498       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 499       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 500     }
 501
 502   if (hosted)
 503     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 504   else
 505     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 506
 507   if (CPP_OPTION (pfile, objc))
 508     _cpp_define_builtin (pfile, "__OBJC__ 1");
 509 }
 510
 511 /* Sanity-checks are dependent on command-line options, so it is
 512    called as a subroutine of cpp_read_main_file ().  */
 513 #if ENABLE_CHECKING
 514 static void sanity_checks (cpp_reader *);
 515 static void sanity_checks (cpp_reader *pfile)
 516 {
 517   cppchar_t test = 0;
 518   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 519
 520   /* Sanity checks for assumptions about CPP arithmetic and target
 521      type precisions made by cpplib.  */
 522   test--;
 523   if (test < 1)
 524     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 525
 526   if (CPP_OPTION (pfile, precision) > max_precision)
 527     cpp_error (pfile, CPP_DL_ICE,
 528                "preprocessor arithmetic has maximum precision of %lu bits;"
 529                " target requires %lu bits",
 530                (unsigned long) max_precision,
 531                (unsigned long) CPP_OPTION (pfile, precision));
 532
 533   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 534     cpp_error (pfile, CPP_DL_ICE,
 535                "CPP arithmetic must be at least as precise as a target int");
 536
 537   if (CPP_OPTION (pfile, char_precision) < 8)
 538     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 539
 540   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 541     cpp_error (pfile, CPP_DL_ICE,
 542                "target wchar_t is narrower than target char");
 543
 544   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 545     cpp_error (pfile, CPP_DL_ICE,
 546                "target int is narrower than target char");
 547
 548   /* This is assumed in eval_token() and could be fixed if necessary.  */
 549   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 550     cpp_error (pfile, CPP_DL_ICE,
 551                "CPP half-integer narrower than CPP character");
 552
 553   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 554     cpp_error (pfile, CPP_DL_ICE,
 555                "CPP on this host cannot handle wide character constants over"
 556                " %lu bits, but the target requires %lu bits",
 557                (unsigned long) BITS_PER_CPPCHAR_T,
 558                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 559 }
 560 #else
 561 # define sanity_checks(PFILE)
 562 #endif
 563
 564 /* This is called after options have been parsed, and partially
 565    processed.  */
 566 void
 567 cpp_post_options (cpp_reader *pfile)
 568 {
 569   int flags;
 570
 571   sanity_checks (pfile);
 572
 573   post_options (pfile);
 574
 575   /* Mark named operators before handling command line macros.  */
 576   flags = 0;
 577   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 578     flags |= NODE_OPERATOR;
 579   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 580     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 581   if (flags != 0)
 582     mark_named_operators (pfile, flags);
 583 }
 584
 585 /* Setup for processing input from the file named FNAME, or stdin if
 586    it is the empty string.  Return the original filename
 587    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 588 const char *
 589 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 590 {
 591   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 592     {
 593       if (!pfile->deps)
 594         pfile->deps = deps_init ();
 595
 596       /* Set the default target (if there is none already).  */
 597       deps_add_default_target (pfile->deps, fname);
 598     }
 599
 600   pfile->main_file
 601     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false);
 602   if (_cpp_find_failed (pfile->main_file))
 603     return NULL;
 604
 605   _cpp_stack_file (pfile, pfile->main_file, false);
 606
 607   /* For foo.i, read the original filename foo.c now, for the benefit
 608      of the front ends.  */
 609   if (CPP_OPTION (pfile, preprocessed))
 610     {
 611       read_original_filename (pfile);
 612       fname =
 613         ORDINARY_MAP_FILE_NAME
 614         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 615     }
 616   return fname;
 617 }
 618
 619 /* For preprocessed files, if the first tokens are of the form # NUM.
 620    handle the directive so we know the original file name.  This will
 621    generate file_change callbacks, which the front ends must handle
 622    appropriately given their state of initialization.  */
 623 static void
 624 read_original_filename (cpp_reader *pfile)
 625 {
 626   const cpp_token *token, *token1;
 627
 628   /* Lex ahead; if the first tokens are of the form # NUM, then
 629      process the directive, otherwise back up.  */
 630   token = _cpp_lex_direct (pfile);
 631   if (token->type == CPP_HASH)
 632     {
 633       pfile->state.in_directive = 1;
 634       token1 = _cpp_lex_direct (pfile);
 635       _cpp_backup_tokens (pfile, 1);
 636       pfile->state.in_directive = 0;
 637
 638       /* If it's a #line directive, handle it.  */
 639       if (token1->type == CPP_NUMBER
 640           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 641         {
 642           read_original_directory (pfile);
 643           return;
 644         }
 645     }
 646
 647   /* Backup as if nothing happened.  */
 648   _cpp_backup_tokens (pfile, 1);
 649 }
 650
 651 /* For preprocessed files, if the tokens following the first filename
 652    line is of the form # <line> "/path/name//", handle the
 653    directive so we know the original current directory.  */
 654 static void
 655 read_original_directory (cpp_reader *pfile)
 656 {
 657   const cpp_token *hash, *token;
 658
 659   /* Lex ahead; if the first tokens are of the form # NUM, then
 660      process the directive, otherwise back up.  */
 661   hash = _cpp_lex_direct (pfile);
 662   if (hash->type != CPP_HASH)
 663     {
 664       _cpp_backup_tokens (pfile, 1);
 665       return;
 666     }
 667
 668   token = _cpp_lex_direct (pfile);
 669
 670   if (token->type != CPP_NUMBER)
 671     {
 672       _cpp_backup_tokens (pfile, 2);
 673       return;
 674     }
 675
 676   token = _cpp_lex_direct (pfile);
 677
 678   if (token->type != CPP_STRING
 679       || ! (token->val.str.len >= 5
 680             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 681             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 682     {
 683       _cpp_backup_tokens (pfile, 3);
 684       return;
 685     }
 686
 687   if (pfile->cb.dir_change)
 688     {
 689       char *debugdir = (char *) alloca (token->val.str.len - 3);
 690
 691       memcpy (debugdir, (const char *) token->val.str.text + 1,
 692               token->val.str.len - 4);
 693       debugdir[token->val.str.len - 4] = '\0';
 694
 695       pfile->cb.dir_change (pfile, debugdir);
 696     }
 697 }
 698
 699 /* This is called at the end of preprocessing.  It pops the last
 700    buffer and writes dependency output.
 701
 702    Maybe it should also reset state, such that you could call
 703    cpp_start_read with a new filename to restart processing.  */
 704 void
 705 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 706 {
 707   /* Warn about unused macros before popping the final buffer.  */
 708   if (CPP_OPTION (pfile, warn_unused_macros))
 709     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 710
 711   /* lex.c leaves the final buffer on the stack.  This it so that
 712      it returns an unending stream of CPP_EOFs to the client.  If we
 713      popped the buffer, we'd dereference a NULL buffer pointer and
 714      segfault.  It's nice to allow the client to do worry-free excess
 715      cpp_get_token calls.  */
 716   while (pfile->buffer)
 717     _cpp_pop_buffer (pfile);
 718
 719   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 720       && deps_stream)
 721     {
 722       deps_write (pfile->deps, deps_stream, 72);
 723
 724       if (CPP_OPTION (pfile, deps.phony_targets))
 725         deps_phony_targets (pfile->deps, deps_stream);
 726     }
 727
 728   /* Report on headers that could use multiple include guards.  */
 729   if (CPP_OPTION (pfile, print_include_names))
 730     _cpp_report_missing_guards (pfile);
 731 }
 732
 733 static void
 734 post_options (cpp_reader *pfile)
 735 {
 736   /* -Wtraditional is not useful in C++ mode.  */
 737   if (CPP_OPTION (pfile, cplusplus))
 738     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 739
 740   /* Permanently disable macro expansion if we are rescanning
 741      preprocessed text.  Read preprocesed source in ISO mode.  */
 742   if (CPP_OPTION (pfile, preprocessed))
 743     {
 744       if (!CPP_OPTION (pfile, directives_only))
 745         pfile->state.prevent_expansion = 1;
 746       CPP_OPTION (pfile, traditional) = 0;
 747     }
 748
 749   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 750     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 751
 752   if (CPP_OPTION (pfile, traditional))
 753     {
 754       CPP_OPTION (pfile, cplusplus_comments) = 0;
 755
 756       CPP_OPTION (pfile, trigraphs) = 0;
 757       CPP_OPTION (pfile, warn_trigraphs) = 0;
 758     }
 759 }