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   char binary_constants;
  87 };
  88
  89 static const struct lang_flags lang_defaults[] =
  90 { /*              c99 c++ xnum xid std  //   digr ulit rlit udlit bin_cst */
  91   /* GNUC89   */  { 0,  0,  1,   0,  0,   1,   1,   0,   0,   0,    0 },
  92   /* GNUC99   */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,   0,    0 },
  93   /* GNUC11   */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,   0,    0 },
  94   /* STDC89   */  { 0,  0,  0,   0,  1,   0,   0,   0,   0,   0,    0 },
  95   /* STDC94   */  { 0,  0,  0,   0,  1,   0,   1,   0,   0,   0,    0 },
  96   /* STDC99   */  { 1,  0,  1,   0,  1,   1,   1,   0,   0,   0,    0 },
  97   /* STDC11   */  { 1,  0,  1,   0,  1,   1,   1,   1,   0,   0,    0 },
  98   /* GNUCXX   */  { 0,  1,  1,   0,  0,   1,   1,   0,   0,   0,    0 },
  99   /* CXX98    */  { 0,  1,  1,   0,  1,   1,   1,   0,   0,   0,    0 },
 100   /* GNUCXX11 */  { 1,  1,  1,   0,  0,   1,   1,   1,   1,   1,    0 },
 101   /* CXX11    */  { 1,  1,  1,   0,  1,   1,   1,   1,   1,   1,    0 },
 102   /* GNUCXX1Y */  { 1,  1,  1,   0,  0,   1,   1,   1,   1,   1,    1 },
 103   /* CXX1Y    */  { 1,  1,  1,   0,  1,   1,   1,   1,   1,   1,    1 },
 104   /* ASM      */  { 0,  0,  1,   0,  0,   1,   0,   0,   0,   0,    0 }
 105   /* xid should be 1 for GNUC99, STDC99, GNUCXX, CXX98, GNUCXX11, CXX11,
 106      GNUCXX1Y, and CXX1Y when no longer experimental (when all uses of
 107      identifiers in the compiler have been audited for correct handling
 108      of extended identifiers).  */
 109 };
 110
 111 /* Sets internal flags correctly for a given language.  */
 112 void
 113 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 114 {
 115   const struct lang_flags *l = &lang_defaults[(int) lang];
 116
 117   CPP_OPTION (pfile, lang) = lang;
 118
 119   CPP_OPTION (pfile, c99)                        = l->c99;
 120   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 121   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 122   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 123   CPP_OPTION (pfile, std)                        = l->std;
 124   CPP_OPTION (pfile, trigraphs)                  = l->std;
 125   CPP_OPTION (pfile, cplusplus_comments)         = l->cplusplus_comments;
 126   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 127   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 128   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 129   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 130   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 131 }
 132
 133 /* Initialize library global state.  */
 134 static void
 135 init_library (void)
 136 {
 137   static int initialized = 0;
 138
 139   if (! initialized)
 140     {
 141       initialized = 1;
 142
 143       _cpp_init_lexer ();
 144
 145       /* Set up the trigraph map.  This doesn't need to do anything if
 146          we were compiled with a compiler that supports C99 designated
 147          initializers.  */
 148       init_trigraph_map ();
 149
 150 #ifdef ENABLE_NLS
 151        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 152 #endif
 153     }
 154 }
 155
 156 /* Initialize a cpp_reader structure.  */
 157 cpp_reader *
 158 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 159                    struct line_maps *line_table)
 160 {
 161   cpp_reader *pfile;
 162
 163   /* Initialize this instance of the library if it hasn't been already.  */
 164   init_library ();
 165
 166   pfile = XCNEW (cpp_reader);
 167   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 168
 169   cpp_set_lang (pfile, lang);
 170   CPP_OPTION (pfile, warn_multichar) = 1;
 171   CPP_OPTION (pfile, discard_comments) = 1;
 172   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 173   CPP_OPTION (pfile, tabstop) = 8;
 174   CPP_OPTION (pfile, operator_names) = 1;
 175   CPP_OPTION (pfile, warn_trigraphs) = 2;
 176   CPP_OPTION (pfile, warn_endif_labels) = 1;
 177   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 178   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 179   CPP_OPTION (pfile, dollars_in_ident) = 1;
 180   CPP_OPTION (pfile, warn_dollars) = 1;
 181   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 182   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 183   /* By default, track locations of tokens resulting from macro
 184      expansion.  The '2' means, track the locations with the highest
 185      accuracy.  Read the comments for struct
 186      cpp_options::track_macro_expansion to learn about the other
 187      values.  */
 188   CPP_OPTION (pfile, track_macro_expansion) = 2;
 189   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 190   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 191   CPP_OPTION (pfile, canonical_system_headers)
 192       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 193   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 194
 195   /* Default CPP arithmetic to something sensible for the host for the
 196      benefit of dumb users like fix-header.  */
 197   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 198   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 199   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 200   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 201   CPP_OPTION (pfile, unsigned_char) = 0;
 202   CPP_OPTION (pfile, unsigned_wchar) = 1;
 203   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 204
 205   /* Default to no charset conversion.  */
 206   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 207   CPP_OPTION (pfile, wide_charset) = 0;
 208
 209   /* Default the input character set to UTF-8.  */
 210   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 211
 212   /* A fake empty "directory" used as the starting point for files
 213      looked up without a search path.  Name cannot be '/' because we
 214      don't want to prepend anything at all to filenames using it.  All
 215      other entries are correct zero-initialized.  */
 216   pfile->no_search_path.name = (char *) "";
 217
 218   /* Initialize the line map.  */
 219   pfile->line_table = line_table;
 220
 221   /* Initialize lexer state.  */
 222   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 223
 224   /* Set up static tokens.  */
 225   pfile->avoid_paste.type = CPP_PADDING;
 226   pfile->avoid_paste.val.source = NULL;
 227   pfile->eof.type = CPP_EOF;
 228   pfile->eof.flags = 0;
 229
 230   /* Create a token buffer for the lexer.  */
 231   _cpp_init_tokenrun (&pfile->base_run, 250);
 232   pfile->cur_run = &pfile->base_run;
 233   pfile->cur_token = pfile->base_run.base;
 234
 235   /* Initialize the base context.  */
 236   pfile->context = &pfile->base_context;
 237   pfile->base_context.c.macro = 0;
 238   pfile->base_context.prev = pfile->base_context.next = 0;
 239
 240   /* Aligned and unaligned storage.  */
 241   pfile->a_buff = _cpp_get_buff (pfile, 0);
 242   pfile->u_buff = _cpp_get_buff (pfile, 0);
 243
 244   /* Initialize table for push_macro/pop_macro.  */
 245   pfile->pushed_macros = 0;
 246
 247   /* Do not force token locations by default.  */
 248   pfile->forced_token_location_p = NULL;
 249
 250   /* The expression parser stack.  */
 251   _cpp_expand_op_stack (pfile);
 252
 253   /* Initialize the buffer obstack.  */
 254   _obstack_begin (&pfile->buffer_ob, 0, 0,
 255                   (void *(*) (long)) xmalloc,
 256                   (void (*) (void *)) free);
 257
 258   _cpp_init_files (pfile);
 259
 260   _cpp_init_hashtable (pfile, table);
 261
 262   return pfile;
 263 }
 264
 265 /* Set the line_table entry in PFILE.  This is called after reading a
 266    PCH file, as the old line_table will be incorrect.  */
 267 void
 268 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 269 {
 270   pfile->line_table = line_table;
 271 }
 272
 273 /* Free resources used by PFILE.  Accessing PFILE after this function
 274    returns leads to undefined behavior.  Returns the error count.  */
 275 void
 276 cpp_destroy (cpp_reader *pfile)
 277 {
 278   cpp_context *context, *contextn;
 279   struct def_pragma_macro *pmacro;
 280   tokenrun *run, *runn;
 281   int i;
 282
 283   free (pfile->op_stack);
 284
 285   while (CPP_BUFFER (pfile) != NULL)
 286     _cpp_pop_buffer (pfile);
 287
 288   free (pfile->out.base);
 289
 290   if (pfile->macro_buffer)
 291     {
 292       free (pfile->macro_buffer);
 293       pfile->macro_buffer = NULL;
 294       pfile->macro_buffer_len = 0;
 295     }
 296
 297   if (pfile->deps)
 298     deps_free (pfile->deps);
 299   obstack_free (&pfile->buffer_ob, 0);
 300
 301   _cpp_destroy_hashtable (pfile);
 302   _cpp_cleanup_files (pfile);
 303   _cpp_destroy_iconv (pfile);
 304
 305   _cpp_free_buff (pfile->a_buff);
 306   _cpp_free_buff (pfile->u_buff);
 307   _cpp_free_buff (pfile->free_buffs);
 308
 309   for (run = &pfile->base_run; run; run = runn)
 310     {
 311       runn = run->next;
 312       free (run->base);
 313       if (run != &pfile->base_run)
 314         free (run);
 315     }
 316
 317   for (context = pfile->base_context.next; context; context = contextn)
 318     {
 319       contextn = context->next;
 320       free (context);
 321     }
 322
 323   if (pfile->comments.entries)
 324     {
 325       for (i = 0; i < pfile->comments.count; i++)
 326         free (pfile->comments.entries[i].comment);
 327
 328       free (pfile->comments.entries);
 329     }
 330   if (pfile->pushed_macros)
 331     {
 332       do
 333         {
 334           pmacro = pfile->pushed_macros;
 335           pfile->pushed_macros = pmacro->next;
 336           free (pmacro->name);
 337           free (pmacro);
 338         }
 339       while (pfile->pushed_macros);
 340     }
 341
 342   free (pfile);
 343 }
 344
 345 /* This structure defines one built-in identifier.  A node will be
 346    entered in the hash table under the name NAME, with value VALUE.
 347
 348    There are two tables of these.  builtin_array holds all the
 349    "builtin" macros: these are handled by builtin_macro() in
 350    macro.c.  Builtin is somewhat of a misnomer -- the property of
 351    interest is that these macros require special code to compute their
 352    expansions.  The value is a "cpp_builtin_type" enumerator.
 353
 354    operator_array holds the C++ named operators.  These are keywords
 355    which act as aliases for punctuators.  In C++, they cannot be
 356    altered through #define, and #if recognizes them as operators.  In
 357    C, these are not entered into the hash table at all (but see
 358    <iso646.h>).  The value is a token-type enumerator.  */
 359 struct builtin_macro
 360 {
 361   const uchar *const name;
 362   const unsigned short len;
 363   const unsigned short value;
 364   const bool always_warn_if_redefined;
 365 };
 366
 367 #define B(n, t, f)    { DSC(n), t, f }
 368 static const struct builtin_macro builtin_array[] =
 369 {
 370   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 371   B("__TIME__",          BT_TIME,          false),
 372   B("__DATE__",          BT_DATE,          false),
 373   B("__FILE__",          BT_FILE,          false),
 374   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 375   B("__LINE__",          BT_SPECLINE,      true),
 376   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 377   B("__COUNTER__",       BT_COUNTER,       true),
 378   /* Keep builtins not used for -traditional-cpp at the end, and
 379      update init_builtins() if any more are added.  */
 380   B("_Pragma",           BT_PRAGMA,        true),
 381   B("__STDC__",          BT_STDC,          true),
 382 };
 383 #undef B
 384
 385 struct builtin_operator
 386 {
 387   const uchar *const name;
 388   const unsigned short len;
 389   const unsigned short value;
 390 };
 391
 392 #define B(n, t)    { DSC(n), t }
 393 static const struct builtin_operator operator_array[] =
 394 {
 395   B("and",      CPP_AND_AND),
 396   B("and_eq",   CPP_AND_EQ),
 397   B("bitand",   CPP_AND),
 398   B("bitor",    CPP_OR),
 399   B("compl",    CPP_COMPL),
 400   B("not",      CPP_NOT),
 401   B("not_eq",   CPP_NOT_EQ),
 402   B("or",       CPP_OR_OR),
 403   B("or_eq",    CPP_OR_EQ),
 404   B("xor",      CPP_XOR),
 405   B("xor_eq",   CPP_XOR_EQ)
 406 };
 407 #undef B
 408
 409 /* Mark the C++ named operators in the hash table.  */
 410 static void
 411 mark_named_operators (cpp_reader *pfile, int flags)
 412 {
 413   const struct builtin_operator *b;
 414
 415   for (b = operator_array;
 416        b < (operator_array + ARRAY_SIZE (operator_array));
 417        b++)
 418     {
 419       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 420       hp->flags |= flags;
 421       hp->is_directive = 0;
 422       hp->directive_index = b->value;
 423     }
 424 }
 425
 426 /* Helper function of cpp_type2name. Return the string associated with
 427    named operator TYPE.  */
 428 const char *
 429 cpp_named_operator2name (enum cpp_ttype type)
 430 {
 431   const struct builtin_operator *b;
 432
 433   for (b = operator_array;
 434        b < (operator_array + ARRAY_SIZE (operator_array));
 435        b++)
 436     {
 437       if (type == b->value)
 438         return (const char *) b->name;
 439     }
 440
 441   return NULL;
 442 }
 443
 444 void
 445 cpp_init_special_builtins (cpp_reader *pfile)
 446 {
 447   const struct builtin_macro *b;
 448   size_t n = ARRAY_SIZE (builtin_array);
 449
 450   if (CPP_OPTION (pfile, traditional))
 451     n -= 2;
 452   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 453            || CPP_OPTION (pfile, std))
 454     n--;
 455
 456   for (b = builtin_array; b < builtin_array + n; b++)
 457     {
 458       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 459       hp->type = NT_MACRO;
 460       hp->flags |= NODE_BUILTIN;
 461       if (b->always_warn_if_redefined
 462           || CPP_OPTION (pfile, warn_builtin_macro_redefined))
 463         hp->flags |= NODE_WARN;
 464       hp->value.builtin = (enum cpp_builtin_type) b->value;
 465     }
 466 }
 467
 468 /* Read the builtins table above and enter them, and language-specific
 469    macros, into the hash table.  HOSTED is true if this is a hosted
 470    environment.  */
 471 void
 472 cpp_init_builtins (cpp_reader *pfile, int hosted)
 473 {
 474   cpp_init_special_builtins (pfile);
 475
 476   if (!CPP_OPTION (pfile, traditional)
 477       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 478           || CPP_OPTION (pfile, std)))
 479     _cpp_define_builtin (pfile, "__STDC__ 1");
 480
 481   if (CPP_OPTION (pfile, cplusplus))
 482     {
 483       if (CPP_OPTION (pfile, lang) == CLK_CXX1Y
 484           || CPP_OPTION (pfile, lang) == CLK_GNUCXX1Y)
 485         _cpp_define_builtin (pfile, "__cplusplus 201300L");
 486       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 487                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 488         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 489       else
 490         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 491     }
 492   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 493     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 494   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 495     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 496   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 497            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 498     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 499   else if (CPP_OPTION (pfile, c99))
 500     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 501
 502   if (CPP_OPTION (pfile, uliterals)
 503       && !CPP_OPTION (pfile, cplusplus))
 504     {
 505       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 506       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 507     }
 508
 509   if (hosted)
 510     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 511   else
 512     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 513
 514   if (CPP_OPTION (pfile, objc))
 515     _cpp_define_builtin (pfile, "__OBJC__ 1");
 516 }
 517
 518 /* Sanity-checks are dependent on command-line options, so it is
 519    called as a subroutine of cpp_read_main_file ().  */
 520 #if ENABLE_CHECKING
 521 static void sanity_checks (cpp_reader *);
 522 static void sanity_checks (cpp_reader *pfile)
 523 {
 524   cppchar_t test = 0;
 525   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 526
 527   /* Sanity checks for assumptions about CPP arithmetic and target
 528      type precisions made by cpplib.  */
 529   test--;
 530   if (test < 1)
 531     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 532
 533   if (CPP_OPTION (pfile, precision) > max_precision)
 534     cpp_error (pfile, CPP_DL_ICE,
 535                "preprocessor arithmetic has maximum precision of %lu bits;"
 536                " target requires %lu bits",
 537                (unsigned long) max_precision,
 538                (unsigned long) CPP_OPTION (pfile, precision));
 539
 540   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 541     cpp_error (pfile, CPP_DL_ICE,
 542                "CPP arithmetic must be at least as precise as a target int");
 543
 544   if (CPP_OPTION (pfile, char_precision) < 8)
 545     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 546
 547   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 548     cpp_error (pfile, CPP_DL_ICE,
 549                "target wchar_t is narrower than target char");
 550
 551   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 552     cpp_error (pfile, CPP_DL_ICE,
 553                "target int is narrower than target char");
 554
 555   /* This is assumed in eval_token() and could be fixed if necessary.  */
 556   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 557     cpp_error (pfile, CPP_DL_ICE,
 558                "CPP half-integer narrower than CPP character");
 559
 560   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 561     cpp_error (pfile, CPP_DL_ICE,
 562                "CPP on this host cannot handle wide character constants over"
 563                " %lu bits, but the target requires %lu bits",
 564                (unsigned long) BITS_PER_CPPCHAR_T,
 565                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 566 }
 567 #else
 568 # define sanity_checks(PFILE)
 569 #endif
 570
 571 /* This is called after options have been parsed, and partially
 572    processed.  */
 573 void
 574 cpp_post_options (cpp_reader *pfile)
 575 {
 576   int flags;
 577
 578   sanity_checks (pfile);
 579
 580   post_options (pfile);
 581
 582   /* Mark named operators before handling command line macros.  */
 583   flags = 0;
 584   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 585     flags |= NODE_OPERATOR;
 586   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 587     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 588   if (flags != 0)
 589     mark_named_operators (pfile, flags);
 590 }
 591
 592 /* Setup for processing input from the file named FNAME, or stdin if
 593    it is the empty string.  Return the original filename
 594    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 595 const char *
 596 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 597 {
 598   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 599     {
 600       if (!pfile->deps)
 601         pfile->deps = deps_init ();
 602
 603       /* Set the default target (if there is none already).  */
 604       deps_add_default_target (pfile->deps, fname);
 605     }
 606
 607   pfile->main_file
 608     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false);
 609   if (_cpp_find_failed (pfile->main_file))
 610     return NULL;
 611
 612   _cpp_stack_file (pfile, pfile->main_file, false);
 613
 614   /* For foo.i, read the original filename foo.c now, for the benefit
 615      of the front ends.  */
 616   if (CPP_OPTION (pfile, preprocessed))
 617     {
 618       read_original_filename (pfile);
 619       fname =
 620         ORDINARY_MAP_FILE_NAME
 621         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 622     }
 623   return fname;
 624 }
 625
 626 /* For preprocessed files, if the first tokens are of the form # NUM.
 627    handle the directive so we know the original file name.  This will
 628    generate file_change callbacks, which the front ends must handle
 629    appropriately given their state of initialization.  */
 630 static void
 631 read_original_filename (cpp_reader *pfile)
 632 {
 633   const cpp_token *token, *token1;
 634
 635   /* Lex ahead; if the first tokens are of the form # NUM, then
 636      process the directive, otherwise back up.  */
 637   token = _cpp_lex_direct (pfile);
 638   if (token->type == CPP_HASH)
 639     {
 640       pfile->state.in_directive = 1;
 641       token1 = _cpp_lex_direct (pfile);
 642       _cpp_backup_tokens (pfile, 1);
 643       pfile->state.in_directive = 0;
 644
 645       /* If it's a #line directive, handle it.  */
 646       if (token1->type == CPP_NUMBER
 647           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 648         {
 649           read_original_directory (pfile);
 650           return;
 651         }
 652     }
 653
 654   /* Backup as if nothing happened.  */
 655   _cpp_backup_tokens (pfile, 1);
 656 }
 657
 658 /* For preprocessed files, if the tokens following the first filename
 659    line is of the form # <line> "/path/name//", handle the
 660    directive so we know the original current directory.  */
 661 static void
 662 read_original_directory (cpp_reader *pfile)
 663 {
 664   const cpp_token *hash, *token;
 665
 666   /* Lex ahead; if the first tokens are of the form # NUM, then
 667      process the directive, otherwise back up.  */
 668   hash = _cpp_lex_direct (pfile);
 669   if (hash->type != CPP_HASH)
 670     {
 671       _cpp_backup_tokens (pfile, 1);
 672       return;
 673     }
 674
 675   token = _cpp_lex_direct (pfile);
 676
 677   if (token->type != CPP_NUMBER)
 678     {
 679       _cpp_backup_tokens (pfile, 2);
 680       return;
 681     }
 682
 683   token = _cpp_lex_direct (pfile);
 684
 685   if (token->type != CPP_STRING
 686       || ! (token->val.str.len >= 5
 687             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 688             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 689     {
 690       _cpp_backup_tokens (pfile, 3);
 691       return;
 692     }
 693
 694   if (pfile->cb.dir_change)
 695     {
 696       char *debugdir = (char *) alloca (token->val.str.len - 3);
 697
 698       memcpy (debugdir, (const char *) token->val.str.text + 1,
 699               token->val.str.len - 4);
 700       debugdir[token->val.str.len - 4] = '\0';
 701
 702       pfile->cb.dir_change (pfile, debugdir);
 703     }
 704 }
 705
 706 /* This is called at the end of preprocessing.  It pops the last
 707    buffer and writes dependency output.
 708
 709    Maybe it should also reset state, such that you could call
 710    cpp_start_read with a new filename to restart processing.  */
 711 void
 712 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 713 {
 714   /* Warn about unused macros before popping the final buffer.  */
 715   if (CPP_OPTION (pfile, warn_unused_macros))
 716     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 717
 718   /* lex.c leaves the final buffer on the stack.  This it so that
 719      it returns an unending stream of CPP_EOFs to the client.  If we
 720      popped the buffer, we'd dereference a NULL buffer pointer and
 721      segfault.  It's nice to allow the client to do worry-free excess
 722      cpp_get_token calls.  */
 723   while (pfile->buffer)
 724     _cpp_pop_buffer (pfile);
 725
 726   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 727       && deps_stream)
 728     {
 729       deps_write (pfile->deps, deps_stream, 72);
 730
 731       if (CPP_OPTION (pfile, deps.phony_targets))
 732         deps_phony_targets (pfile->deps, deps_stream);
 733     }
 734
 735   /* Report on headers that could use multiple include guards.  */
 736   if (CPP_OPTION (pfile, print_include_names))
 737     _cpp_report_missing_guards (pfile);
 738 }
 739
 740 static void
 741 post_options (cpp_reader *pfile)
 742 {
 743   /* -Wtraditional is not useful in C++ mode.  */
 744   if (CPP_OPTION (pfile, cplusplus))
 745     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 746
 747   /* Permanently disable macro expansion if we are rescanning
 748      preprocessed text.  Read preprocesed source in ISO mode.  */
 749   if (CPP_OPTION (pfile, preprocessed))
 750     {
 751       if (!CPP_OPTION (pfile, directives_only))
 752         pfile->state.prevent_expansion = 1;
 753       CPP_OPTION (pfile, traditional) = 0;
 754     }
 755
 756   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 757     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 758
 759   if (CPP_OPTION (pfile, traditional))
 760     {
 761       CPP_OPTION (pfile, cplusplus_comments) = 0;
 762
 763       CPP_OPTION (pfile, trigraphs) = 0;
 764       CPP_OPTION (pfile, warn_trigraphs) = 0;
 765     }
 766 }