libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2016 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 #ifdef HAVE_DOS_BASED_FILE_SYSTEM
  31 #define ENABLE_CANONICAL_SYSTEM_HEADERS 1
  32 #else
  33 #define ENABLE_CANONICAL_SYSTEM_HEADERS 0
  34 #endif
  35 #endif
  36
  37 static void init_library (void);
  38 static void mark_named_operators (cpp_reader *, int);
  39 static void read_original_filename (cpp_reader *);
  40 static void read_original_directory (cpp_reader *);
  41 static void post_options (cpp_reader *);
  42
  43 /* If we have designated initializers (GCC >2.7) these tables can be
  44    initialized, constant data.  Otherwise, they have to be filled in at
  45    runtime.  */
  46 #if HAVE_DESIGNATED_INITIALIZERS
  47
  48 #define init_trigraph_map()  /* Nothing.  */
  49 #define TRIGRAPH_MAP \
  50 __extension__ const uchar _cpp_trigraph_map[UCHAR_MAX + 1] = {
  51
  52 #define END };
  53 #define s(p, v) [p] = v,
  54
  55 #else
  56
  57 #define TRIGRAPH_MAP uchar _cpp_trigraph_map[UCHAR_MAX + 1] = { 0 }; \
  58  static void init_trigraph_map (void) { \
  59  unsigned char *x = _cpp_trigraph_map;
  60
  61 #define END }
  62 #define s(p, v) x[p] = v;
  63
  64 #endif
  65
  66 TRIGRAPH_MAP
  67   s('=', '#')   s(')', ']')     s('!', '|')
  68   s('(', '[')   s('\'', '^')    s('>', '}')
  69   s('/', '\\')  s('<', '{')     s('-', '~')
  70 END
  71
  72 #undef s
  73 #undef END
  74 #undef TRIGRAPH_MAP
  75
  76 /* A set of booleans indicating what CPP features each source language
  77    requires.  */
  78 struct lang_flags
  79 {
  80   char c99;
  81   char cplusplus;
  82   char extended_numbers;
  83   char extended_identifiers;
  84   char c11_identifiers;
  85   char std;
  86   char digraphs;
  87   char uliterals;
  88   char rliterals;
  89   char user_literals;
  90   char binary_constants;
  91   char digit_separators;
  92   char trigraphs;
  93   char utf8_char_literals;
  94 };
  95
  96 static const struct lang_flags lang_defaults[] =
  97 { /*              c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit */
  98   /* GNUC89   */  { 0,  0,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0 },
  99   /* GNUC99   */  { 1,  0,  1,  1,  0,  0,  1,   1,   1,   0,    0,     0,     0,   0 },
 100   /* GNUC11   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0 },
 101   /* STDC89   */  { 0,  0,  0,  0,  0,  1,  0,   0,   0,   0,    0,     0,     1,   0 },
 102   /* STDC94   */  { 0,  0,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0 },
 103   /* STDC99   */  { 1,  0,  1,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0 },
 104   /* STDC11   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0 },
 105   /* GNUCXX   */  { 0,  1,  1,  1,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0 },
 106   /* CXX98    */  { 0,  1,  0,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0 },
 107   /* GNUCXX11 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    0,     0,     0,   0 },
 108   /* CXX11    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    0,     0,     1,   0 },
 109   /* GNUCXX14 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   0 },
 110   /* CXX14    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    1,     1,     1,   0 },
 111   /* GNUCXX1Z */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1 },
 112   /* CXX1Z    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1 },
 113   /* ASM      */  { 0,  0,  1,  0,  0,  0,  0,   0,   0,   0,    0,     0,     0,   0 }
 114 };
 115
 116 /* Sets internal flags correctly for a given language.  */
 117 void
 118 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 119 {
 120   const struct lang_flags *l = &lang_defaults[(int) lang];
 121
 122   CPP_OPTION (pfile, lang) = lang;
 123
 124   CPP_OPTION (pfile, c99)                        = l->c99;
 125   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 126   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 127   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 128   CPP_OPTION (pfile, c11_identifiers)            = l->c11_identifiers;
 129   CPP_OPTION (pfile, std)                        = l->std;
 130   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 131   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 132   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 133   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 134   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 135   CPP_OPTION (pfile, digit_separators)           = l->digit_separators;
 136   CPP_OPTION (pfile, trigraphs)                  = l->trigraphs;
 137   CPP_OPTION (pfile, utf8_char_literals)         = l->utf8_char_literals;
 138 }
 139
 140 /* Initialize library global state.  */
 141 static void
 142 init_library (void)
 143 {
 144   static int initialized = 0;
 145
 146   if (! initialized)
 147     {
 148       initialized = 1;
 149
 150       _cpp_init_lexer ();
 151
 152       /* Set up the trigraph map.  This doesn't need to do anything if
 153          we were compiled with a compiler that supports C99 designated
 154          initializers.  */
 155       init_trigraph_map ();
 156
 157 #ifdef ENABLE_NLS
 158        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 159 #endif
 160     }
 161 }
 162
 163 /* Initialize a cpp_reader structure.  */
 164 cpp_reader *
 165 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 166                    struct line_maps *line_table)
 167 {
 168   cpp_reader *pfile;
 169
 170   /* Initialize this instance of the library if it hasn't been already.  */
 171   init_library ();
 172
 173   pfile = XCNEW (cpp_reader);
 174   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 175
 176   cpp_set_lang (pfile, lang);
 177   CPP_OPTION (pfile, warn_multichar) = 1;
 178   CPP_OPTION (pfile, discard_comments) = 1;
 179   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 180   CPP_OPTION (pfile, tabstop) = 8;
 181   CPP_OPTION (pfile, operator_names) = 1;
 182   CPP_OPTION (pfile, warn_trigraphs) = 2;
 183   CPP_OPTION (pfile, warn_endif_labels) = 1;
 184   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
 185   CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0;
 186   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 187   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 188   CPP_OPTION (pfile, dollars_in_ident) = 1;
 189   CPP_OPTION (pfile, warn_dollars) = 1;
 190   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 191   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 192   /* By default, track locations of tokens resulting from macro
 193      expansion.  The '2' means, track the locations with the highest
 194      accuracy.  Read the comments for struct
 195      cpp_options::track_macro_expansion to learn about the other
 196      values.  */
 197   CPP_OPTION (pfile, track_macro_expansion) = 2;
 198   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 199   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 200   CPP_OPTION (pfile, canonical_system_headers)
 201       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 202   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 203   CPP_OPTION (pfile, warn_date_time) = 0;
 204
 205   /* Default CPP arithmetic to something sensible for the host for the
 206      benefit of dumb users like fix-header.  */
 207   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 208   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 209   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 210   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 211   CPP_OPTION (pfile, unsigned_char) = 0;
 212   CPP_OPTION (pfile, unsigned_wchar) = 1;
 213   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 214
 215   /* Default to no charset conversion.  */
 216   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 217   CPP_OPTION (pfile, wide_charset) = 0;
 218
 219   /* Default the input character set to UTF-8.  */
 220   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 221
 222   /* A fake empty "directory" used as the starting point for files
 223      looked up without a search path.  Name cannot be '/' because we
 224      don't want to prepend anything at all to filenames using it.  All
 225      other entries are correct zero-initialized.  */
 226   pfile->no_search_path.name = (char *) "";
 227
 228   /* Initialize the line map.  */
 229   pfile->line_table = line_table;
 230
 231   /* Initialize lexer state.  */
 232   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 233
 234   /* Set up static tokens.  */
 235   pfile->avoid_paste.type = CPP_PADDING;
 236   pfile->avoid_paste.val.source = NULL;
 237   pfile->eof.type = CPP_EOF;
 238   pfile->eof.flags = 0;
 239
 240   /* Create a token buffer for the lexer.  */
 241   _cpp_init_tokenrun (&pfile->base_run, 250);
 242   pfile->cur_run = &pfile->base_run;
 243   pfile->cur_token = pfile->base_run.base;
 244
 245   /* Initialize the base context.  */
 246   pfile->context = &pfile->base_context;
 247   pfile->base_context.c.macro = 0;
 248   pfile->base_context.prev = pfile->base_context.next = 0;
 249
 250   /* Aligned and unaligned storage.  */
 251   pfile->a_buff = _cpp_get_buff (pfile, 0);
 252   pfile->u_buff = _cpp_get_buff (pfile, 0);
 253
 254   /* Initialize table for push_macro/pop_macro.  */
 255   pfile->pushed_macros = 0;
 256
 257   /* Do not force token locations by default.  */
 258   pfile->forced_token_location_p = NULL;
 259
 260   /* Initialize source_date_epoch to -2 (not yet set).  */
 261   pfile->source_date_epoch = (time_t) -2;
 262
 263   /* The expression parser stack.  */
 264   _cpp_expand_op_stack (pfile);
 265
 266   /* Initialize the buffer obstack.  */
 267   obstack_specify_allocation (&pfile->buffer_ob, 0, 0, xmalloc, free);
 268
 269   _cpp_init_files (pfile);
 270
 271   _cpp_init_hashtable (pfile, table);
 272
 273   return pfile;
 274 }
 275
 276 /* Set the line_table entry in PFILE.  This is called after reading a
 277    PCH file, as the old line_table will be incorrect.  */
 278 void
 279 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 280 {
 281   pfile->line_table = line_table;
 282 }
 283
 284 /* Free resources used by PFILE.  Accessing PFILE after this function
 285    returns leads to undefined behavior.  Returns the error count.  */
 286 void
 287 cpp_destroy (cpp_reader *pfile)
 288 {
 289   cpp_context *context, *contextn;
 290   struct def_pragma_macro *pmacro;
 291   tokenrun *run, *runn;
 292   int i;
 293
 294   free (pfile->op_stack);
 295
 296   while (CPP_BUFFER (pfile) != NULL)
 297     _cpp_pop_buffer (pfile);
 298
 299   free (pfile->out.base);
 300
 301   if (pfile->macro_buffer)
 302     {
 303       free (pfile->macro_buffer);
 304       pfile->macro_buffer = NULL;
 305       pfile->macro_buffer_len = 0;
 306     }
 307
 308   if (pfile->deps)
 309     deps_free (pfile->deps);
 310   obstack_free (&pfile->buffer_ob, 0);
 311
 312   _cpp_destroy_hashtable (pfile);
 313   _cpp_cleanup_files (pfile);
 314   _cpp_destroy_iconv (pfile);
 315
 316   _cpp_free_buff (pfile->a_buff);
 317   _cpp_free_buff (pfile->u_buff);
 318   _cpp_free_buff (pfile->free_buffs);
 319
 320   for (run = &pfile->base_run; run; run = runn)
 321     {
 322       runn = run->next;
 323       free (run->base);
 324       if (run != &pfile->base_run)
 325         free (run);
 326     }
 327
 328   for (context = pfile->base_context.next; context; context = contextn)
 329     {
 330       contextn = context->next;
 331       free (context);
 332     }
 333
 334   if (pfile->comments.entries)
 335     {
 336       for (i = 0; i < pfile->comments.count; i++)
 337         free (pfile->comments.entries[i].comment);
 338
 339       free (pfile->comments.entries);
 340     }
 341   if (pfile->pushed_macros)
 342     {
 343       do
 344         {
 345           pmacro = pfile->pushed_macros;
 346           pfile->pushed_macros = pmacro->next;
 347           free (pmacro->name);
 348           free (pmacro);
 349         }
 350       while (pfile->pushed_macros);
 351     }
 352
 353   free (pfile);
 354 }
 355
 356 /* This structure defines one built-in identifier.  A node will be
 357    entered in the hash table under the name NAME, with value VALUE.
 358
 359    There are two tables of these.  builtin_array holds all the
 360    "builtin" macros: these are handled by builtin_macro() in
 361    macro.c.  Builtin is somewhat of a misnomer -- the property of
 362    interest is that these macros require special code to compute their
 363    expansions.  The value is a "cpp_builtin_type" enumerator.
 364
 365    operator_array holds the C++ named operators.  These are keywords
 366    which act as aliases for punctuators.  In C++, they cannot be
 367    altered through #define, and #if recognizes them as operators.  In
 368    C, these are not entered into the hash table at all (but see
 369    <iso646.h>).  The value is a token-type enumerator.  */
 370 struct builtin_macro
 371 {
 372   const uchar *const name;
 373   const unsigned short len;
 374   const unsigned short value;
 375   const bool always_warn_if_redefined;
 376 };
 377
 378 #define B(n, t, f)    { DSC(n), t, f }
 379 static const struct builtin_macro builtin_array[] =
 380 {
 381   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 382   B("__TIME__",          BT_TIME,          false),
 383   B("__DATE__",          BT_DATE,          false),
 384   B("__FILE__",          BT_FILE,          false),
 385   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 386   B("__LINE__",          BT_SPECLINE,      true),
 387   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 388   B("__COUNTER__",       BT_COUNTER,       true),
 389   B("__has_attribute",   BT_HAS_ATTRIBUTE, true),
 390   B("__has_cpp_attribute", BT_HAS_ATTRIBUTE, true),
 391   /* Keep builtins not used for -traditional-cpp at the end, and
 392      update init_builtins() if any more are added.  */
 393   B("_Pragma",           BT_PRAGMA,        true),
 394   B("__STDC__",          BT_STDC,          true),
 395 };
 396 #undef B
 397
 398 struct builtin_operator
 399 {
 400   const uchar *const name;
 401   const unsigned short len;
 402   const unsigned short value;
 403 };
 404
 405 #define B(n, t)    { DSC(n), t }
 406 static const struct builtin_operator operator_array[] =
 407 {
 408   B("and",      CPP_AND_AND),
 409   B("and_eq",   CPP_AND_EQ),
 410   B("bitand",   CPP_AND),
 411   B("bitor",    CPP_OR),
 412   B("compl",    CPP_COMPL),
 413   B("not",      CPP_NOT),
 414   B("not_eq",   CPP_NOT_EQ),
 415   B("or",       CPP_OR_OR),
 416   B("or_eq",    CPP_OR_EQ),
 417   B("xor",      CPP_XOR),
 418   B("xor_eq",   CPP_XOR_EQ)
 419 };
 420 #undef B
 421
 422 /* Mark the C++ named operators in the hash table.  */
 423 static void
 424 mark_named_operators (cpp_reader *pfile, int flags)
 425 {
 426   const struct builtin_operator *b;
 427
 428   for (b = operator_array;
 429        b < (operator_array + ARRAY_SIZE (operator_array));
 430        b++)
 431     {
 432       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 433       hp->flags |= flags;
 434       hp->is_directive = 0;
 435       hp->directive_index = b->value;
 436     }
 437 }
 438
 439 /* Helper function of cpp_type2name. Return the string associated with
 440    named operator TYPE.  */
 441 const char *
 442 cpp_named_operator2name (enum cpp_ttype type)
 443 {
 444   const struct builtin_operator *b;
 445
 446   for (b = operator_array;
 447        b < (operator_array + ARRAY_SIZE (operator_array));
 448        b++)
 449     {
 450       if (type == b->value)
 451         return (const char *) b->name;
 452     }
 453
 454   return NULL;
 455 }
 456
 457 void
 458 cpp_init_special_builtins (cpp_reader *pfile)
 459 {
 460   const struct builtin_macro *b;
 461   size_t n = ARRAY_SIZE (builtin_array);
 462
 463   if (CPP_OPTION (pfile, traditional))
 464     n -= 2;
 465   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 466            || CPP_OPTION (pfile, std))
 467     n--;
 468
 469   for (b = builtin_array; b < builtin_array + n; b++)
 470     {
 471       if (b->value == BT_HAS_ATTRIBUTE
 472           && (CPP_OPTION (pfile, lang) == CLK_ASM
 473               || pfile->cb.has_attribute == NULL))
 474         continue;
 475       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 476       hp->type = NT_MACRO;
 477       hp->flags |= NODE_BUILTIN;
 478       if (b->always_warn_if_redefined)
 479         hp->flags |= NODE_WARN;
 480       hp->value.builtin = (enum cpp_builtin_type) b->value;
 481     }
 482 }
 483
 484 /* Read the builtins table above and enter them, and language-specific
 485    macros, into the hash table.  HOSTED is true if this is a hosted
 486    environment.  */
 487 void
 488 cpp_init_builtins (cpp_reader *pfile, int hosted)
 489 {
 490   cpp_init_special_builtins (pfile);
 491
 492   if (!CPP_OPTION (pfile, traditional)
 493       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 494           || CPP_OPTION (pfile, std)))
 495     _cpp_define_builtin (pfile, "__STDC__ 1");
 496
 497   if (CPP_OPTION (pfile, cplusplus))
 498     {
 499       if (CPP_OPTION (pfile, lang) == CLK_CXX1Z
 500           || CPP_OPTION (pfile, lang) == CLK_GNUCXX1Z)
 501         _cpp_define_builtin (pfile, "__cplusplus 201500L");
 502       else if (CPP_OPTION (pfile, lang) == CLK_CXX14
 503           || CPP_OPTION (pfile, lang) == CLK_GNUCXX14)
 504         _cpp_define_builtin (pfile, "__cplusplus 201402L");
 505       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 506                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 507         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 508       else
 509         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 510     }
 511   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 512     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 513   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 514     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 515   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 516            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 517     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 518   else if (CPP_OPTION (pfile, c99))
 519     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 520
 521   if (CPP_OPTION (pfile, uliterals)
 522       && !(CPP_OPTION (pfile, cplusplus)
 523            && (CPP_OPTION (pfile, lang) == CLK_GNUCXX
 524             || CPP_OPTION (pfile, lang) == CLK_CXX98)))
 525     {
 526       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 527       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 528     }
 529
 530   if (hosted)
 531     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 532   else
 533     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 534
 535   if (CPP_OPTION (pfile, objc))
 536     _cpp_define_builtin (pfile, "__OBJC__ 1");
 537 }
 538
 539 /* Sanity-checks are dependent on command-line options, so it is
 540    called as a subroutine of cpp_read_main_file.  */
 541 #if CHECKING_P
 542 static void sanity_checks (cpp_reader *);
 543 static void sanity_checks (cpp_reader *pfile)
 544 {
 545   cppchar_t test = 0;
 546   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 547
 548   /* Sanity checks for assumptions about CPP arithmetic and target
 549      type precisions made by cpplib.  */
 550   test--;
 551   if (test < 1)
 552     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 553
 554   if (CPP_OPTION (pfile, precision) > max_precision)
 555     cpp_error (pfile, CPP_DL_ICE,
 556                "preprocessor arithmetic has maximum precision of %lu bits;"
 557                " target requires %lu bits",
 558                (unsigned long) max_precision,
 559                (unsigned long) CPP_OPTION (pfile, precision));
 560
 561   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 562     cpp_error (pfile, CPP_DL_ICE,
 563                "CPP arithmetic must be at least as precise as a target int");
 564
 565   if (CPP_OPTION (pfile, char_precision) < 8)
 566     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 567
 568   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 569     cpp_error (pfile, CPP_DL_ICE,
 570                "target wchar_t is narrower than target char");
 571
 572   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 573     cpp_error (pfile, CPP_DL_ICE,
 574                "target int is narrower than target char");
 575
 576   /* This is assumed in eval_token() and could be fixed if necessary.  */
 577   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 578     cpp_error (pfile, CPP_DL_ICE,
 579                "CPP half-integer narrower than CPP character");
 580
 581   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 582     cpp_error (pfile, CPP_DL_ICE,
 583                "CPP on this host cannot handle wide character constants over"
 584                " %lu bits, but the target requires %lu bits",
 585                (unsigned long) BITS_PER_CPPCHAR_T,
 586                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 587 }
 588 #else
 589 # define sanity_checks(PFILE)
 590 #endif
 591
 592 /* This is called after options have been parsed, and partially
 593    processed.  */
 594 void
 595 cpp_post_options (cpp_reader *pfile)
 596 {
 597   int flags;
 598
 599   sanity_checks (pfile);
 600
 601   post_options (pfile);
 602
 603   /* Mark named operators before handling command line macros.  */
 604   flags = 0;
 605   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 606     flags |= NODE_OPERATOR;
 607   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 608     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 609   if (flags != 0)
 610     mark_named_operators (pfile, flags);
 611 }
 612
 613 /* Setup for processing input from the file named FNAME, or stdin if
 614    it is the empty string.  Return the original filename
 615    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 616 const char *
 617 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 618 {
 619   const source_location loc = 0;
 620
 621   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 622     {
 623       if (!pfile->deps)
 624         pfile->deps = deps_init ();
 625
 626       /* Set the default target (if there is none already).  */
 627       deps_add_default_target (pfile->deps, fname);
 628     }
 629
 630   pfile->main_file
 631     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false,
 632                       loc);
 633   if (_cpp_find_failed (pfile->main_file))
 634     return NULL;
 635
 636   _cpp_stack_file (pfile, pfile->main_file, false, loc);
 637
 638   /* For foo.i, read the original filename foo.c now, for the benefit
 639      of the front ends.  */
 640   if (CPP_OPTION (pfile, preprocessed))
 641     {
 642       read_original_filename (pfile);
 643       fname =
 644         ORDINARY_MAP_FILE_NAME
 645         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 646     }
 647   return fname;
 648 }
 649
 650 /* For preprocessed files, if the first tokens are of the form # NUM.
 651    handle the directive so we know the original file name.  This will
 652    generate file_change callbacks, which the front ends must handle
 653    appropriately given their state of initialization.  */
 654 static void
 655 read_original_filename (cpp_reader *pfile)
 656 {
 657   const cpp_token *token, *token1;
 658
 659   /* Lex ahead; if the first tokens are of the form # NUM, then
 660      process the directive, otherwise back up.  */
 661   token = _cpp_lex_direct (pfile);
 662   if (token->type == CPP_HASH)
 663     {
 664       pfile->state.in_directive = 1;
 665       token1 = _cpp_lex_direct (pfile);
 666       _cpp_backup_tokens (pfile, 1);
 667       pfile->state.in_directive = 0;
 668
 669       /* If it's a #line directive, handle it.  */
 670       if (token1->type == CPP_NUMBER
 671           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 672         {
 673           read_original_directory (pfile);
 674           return;
 675         }
 676     }
 677
 678   /* Backup as if nothing happened.  */
 679   _cpp_backup_tokens (pfile, 1);
 680 }
 681
 682 /* For preprocessed files, if the tokens following the first filename
 683    line is of the form # <line> "/path/name//", handle the
 684    directive so we know the original current directory.  */
 685 static void
 686 read_original_directory (cpp_reader *pfile)
 687 {
 688   const cpp_token *hash, *token;
 689
 690   /* Lex ahead; if the first tokens are of the form # NUM, then
 691      process the directive, otherwise back up.  */
 692   hash = _cpp_lex_direct (pfile);
 693   if (hash->type != CPP_HASH)
 694     {
 695       _cpp_backup_tokens (pfile, 1);
 696       return;
 697     }
 698
 699   token = _cpp_lex_direct (pfile);
 700
 701   if (token->type != CPP_NUMBER)
 702     {
 703       _cpp_backup_tokens (pfile, 2);
 704       return;
 705     }
 706
 707   token = _cpp_lex_direct (pfile);
 708
 709   if (token->type != CPP_STRING
 710       || ! (token->val.str.len >= 5
 711             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 712             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 713     {
 714       _cpp_backup_tokens (pfile, 3);
 715       return;
 716     }
 717
 718   if (pfile->cb.dir_change)
 719     {
 720       char *debugdir = (char *) alloca (token->val.str.len - 3);
 721
 722       memcpy (debugdir, (const char *) token->val.str.text + 1,
 723               token->val.str.len - 4);
 724       debugdir[token->val.str.len - 4] = '\0';
 725
 726       pfile->cb.dir_change (pfile, debugdir);
 727     }
 728 }
 729
 730 /* This is called at the end of preprocessing.  It pops the last
 731    buffer and writes dependency output.
 732
 733    Maybe it should also reset state, such that you could call
 734    cpp_start_read with a new filename to restart processing.  */
 735 void
 736 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 737 {
 738   /* Warn about unused macros before popping the final buffer.  */
 739   if (CPP_OPTION (pfile, warn_unused_macros))
 740     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 741
 742   /* lex.c leaves the final buffer on the stack.  This it so that
 743      it returns an unending stream of CPP_EOFs to the client.  If we
 744      popped the buffer, we'd dereference a NULL buffer pointer and
 745      segfault.  It's nice to allow the client to do worry-free excess
 746      cpp_get_token calls.  */
 747   while (pfile->buffer)
 748     _cpp_pop_buffer (pfile);
 749
 750   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 751       && deps_stream)
 752     {
 753       deps_write (pfile->deps, deps_stream, 72);
 754
 755       if (CPP_OPTION (pfile, deps.phony_targets))
 756         deps_phony_targets (pfile->deps, deps_stream);
 757     }
 758
 759   /* Report on headers that could use multiple include guards.  */
 760   if (CPP_OPTION (pfile, print_include_names))
 761     _cpp_report_missing_guards (pfile);
 762 }
 763
 764 static void
 765 post_options (cpp_reader *pfile)
 766 {
 767   /* -Wtraditional is not useful in C++ mode.  */
 768   if (CPP_OPTION (pfile, cplusplus))
 769     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 770
 771   /* Permanently disable macro expansion if we are rescanning
 772      preprocessed text.  Read preprocesed source in ISO mode.  */
 773   if (CPP_OPTION (pfile, preprocessed))
 774     {
 775       if (!CPP_OPTION (pfile, directives_only))
 776         pfile->state.prevent_expansion = 1;
 777       CPP_OPTION (pfile, traditional) = 0;
 778     }
 779
 780   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 781     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 782
 783   if (CPP_OPTION (pfile, traditional))
 784     {
 785       CPP_OPTION (pfile, trigraphs) = 0;
 786       CPP_OPTION (pfile, warn_trigraphs) = 0;
 787     }
 788 }