libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2014 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 };
  94
  95 static const struct lang_flags lang_defaults[] =
  96 { /*              c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig */
  97   /* GNUC89   */  { 0,  0,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0 },
  98   /* GNUC99   */  { 1,  0,  1,  0,  0,  0,  1,   1,   1,   0,    0,     0,     0 },
  99   /* GNUC11   */  { 1,  0,  1,  0,  1,  0,  1,   1,   1,   0,    0,     0,     0 },
 100   /* STDC89   */  { 0,  0,  0,  0,  0,  1,  0,   0,   0,   0,    0,     0,     1 },
 101   /* STDC94   */  { 0,  0,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1 },
 102   /* STDC99   */  { 1,  0,  1,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1 },
 103   /* STDC11   */  { 1,  0,  1,  0,  1,  1,  1,   1,   0,   0,    0,     0,     1 },
 104   /* GNUCXX   */  { 0,  1,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0 },
 105   /* CXX98    */  { 0,  1,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1 },
 106   /* GNUCXX11 */  { 1,  1,  1,  0,  1,  0,  1,   1,   1,   1,    0,     0,     0 },
 107   /* CXX11    */  { 1,  1,  1,  0,  1,  1,  1,   1,   1,   1,    0,     0,     1 },
 108   /* GNUCXX14 */  { 1,  1,  1,  0,  1,  0,  1,   1,   1,   1,    1,     1,     0 },
 109   /* CXX14    */  { 1,  1,  1,  0,  1,  1,  1,   1,   1,   1,    1,     1,     1 },
 110   /* GNUCXX1Z */  { 1,  1,  1,  0,  1,  0,  1,   1,   1,   1,    1,     1,     0 },
 111   /* CXX1Z    */  { 1,  1,  1,  0,  1,  1,  1,   1,   1,   1,    1,     1,     0 },
 112   /* ASM      */  { 0,  0,  1,  0,  0,  0,  0,   0,   0,   0,    0,     0,     0 }
 113   /* xid should be 1 for GNUC99, STDC99, GNUCXX, CXX98, GNUCXX11, CXX11,
 114      GNUCXX14, and CXX14 when no longer experimental (when all uses of
 115      identifiers in the compiler have been audited for correct handling
 116      of extended identifiers).  */
 117 };
 118
 119 /* Sets internal flags correctly for a given language.  */
 120 void
 121 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 122 {
 123   const struct lang_flags *l = &lang_defaults[(int) lang];
 124
 125   CPP_OPTION (pfile, lang) = lang;
 126
 127   CPP_OPTION (pfile, c99)                        = l->c99;
 128   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 129   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 130   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 131   CPP_OPTION (pfile, c11_identifiers)            = l->c11_identifiers;
 132   CPP_OPTION (pfile, std)                        = l->std;
 133   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 134   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 135   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 136   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 137   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 138   CPP_OPTION (pfile, digit_separators)           = l->digit_separators;
 139   CPP_OPTION (pfile, trigraphs)                  = l->trigraphs;
 140 }
 141
 142 /* Initialize library global state.  */
 143 static void
 144 init_library (void)
 145 {
 146   static int initialized = 0;
 147
 148   if (! initialized)
 149     {
 150       initialized = 1;
 151
 152       _cpp_init_lexer ();
 153
 154       /* Set up the trigraph map.  This doesn't need to do anything if
 155          we were compiled with a compiler that supports C99 designated
 156          initializers.  */
 157       init_trigraph_map ();
 158
 159 #ifdef ENABLE_NLS
 160        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 161 #endif
 162     }
 163 }
 164
 165 /* Initialize a cpp_reader structure.  */
 166 cpp_reader *
 167 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 168                    struct line_maps *line_table)
 169 {
 170   cpp_reader *pfile;
 171
 172   /* Initialize this instance of the library if it hasn't been already.  */
 173   init_library ();
 174
 175   pfile = XCNEW (cpp_reader);
 176   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 177
 178   cpp_set_lang (pfile, lang);
 179   CPP_OPTION (pfile, warn_multichar) = 1;
 180   CPP_OPTION (pfile, discard_comments) = 1;
 181   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 182   CPP_OPTION (pfile, tabstop) = 8;
 183   CPP_OPTION (pfile, operator_names) = 1;
 184   CPP_OPTION (pfile, warn_trigraphs) = 2;
 185   CPP_OPTION (pfile, warn_endif_labels) = 1;
 186   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
 187   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 188   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 189   CPP_OPTION (pfile, dollars_in_ident) = 1;
 190   CPP_OPTION (pfile, warn_dollars) = 1;
 191   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 192   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 193   /* By default, track locations of tokens resulting from macro
 194      expansion.  The '2' means, track the locations with the highest
 195      accuracy.  Read the comments for struct
 196      cpp_options::track_macro_expansion to learn about the other
 197      values.  */
 198   CPP_OPTION (pfile, track_macro_expansion) = 2;
 199   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 200   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 201   CPP_OPTION (pfile, canonical_system_headers)
 202       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 203   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 204   CPP_OPTION (pfile, warn_date_time) = 0;
 205
 206   /* Default CPP arithmetic to something sensible for the host for the
 207      benefit of dumb users like fix-header.  */
 208   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 209   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 210   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 211   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 212   CPP_OPTION (pfile, unsigned_char) = 0;
 213   CPP_OPTION (pfile, unsigned_wchar) = 1;
 214   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 215
 216   /* Default to no charset conversion.  */
 217   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 218   CPP_OPTION (pfile, wide_charset) = 0;
 219
 220   /* Default the input character set to UTF-8.  */
 221   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 222
 223   /* A fake empty "directory" used as the starting point for files
 224      looked up without a search path.  Name cannot be '/' because we
 225      don't want to prepend anything at all to filenames using it.  All
 226      other entries are correct zero-initialized.  */
 227   pfile->no_search_path.name = (char *) "";
 228
 229   /* Initialize the line map.  */
 230   pfile->line_table = line_table;
 231
 232   /* Initialize lexer state.  */
 233   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 234
 235   /* Set up static tokens.  */
 236   pfile->avoid_paste.type = CPP_PADDING;
 237   pfile->avoid_paste.val.source = NULL;
 238   pfile->eof.type = CPP_EOF;
 239   pfile->eof.flags = 0;
 240
 241   /* Create a token buffer for the lexer.  */
 242   _cpp_init_tokenrun (&pfile->base_run, 250);
 243   pfile->cur_run = &pfile->base_run;
 244   pfile->cur_token = pfile->base_run.base;
 245
 246   /* Initialize the base context.  */
 247   pfile->context = &pfile->base_context;
 248   pfile->base_context.c.macro = 0;
 249   pfile->base_context.prev = pfile->base_context.next = 0;
 250
 251   /* Aligned and unaligned storage.  */
 252   pfile->a_buff = _cpp_get_buff (pfile, 0);
 253   pfile->u_buff = _cpp_get_buff (pfile, 0);
 254
 255   /* Initialize table for push_macro/pop_macro.  */
 256   pfile->pushed_macros = 0;
 257
 258   /* Do not force token locations by default.  */
 259   pfile->forced_token_location_p = NULL;
 260
 261   /* The expression parser stack.  */
 262   _cpp_expand_op_stack (pfile);
 263
 264   /* Initialize the buffer obstack.  */
 265   _obstack_begin (&pfile->buffer_ob, 0, 0,
 266                   (void *(*) (long)) xmalloc,
 267                   (void (*) (void *)) 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   /* Keep builtins not used for -traditional-cpp at the end, and
 390      update init_builtins() if any more are added.  */
 391   B("_Pragma",           BT_PRAGMA,        true),
 392   B("__STDC__",          BT_STDC,          true),
 393 };
 394 #undef B
 395
 396 struct builtin_operator
 397 {
 398   const uchar *const name;
 399   const unsigned short len;
 400   const unsigned short value;
 401 };
 402
 403 #define B(n, t)    { DSC(n), t }
 404 static const struct builtin_operator operator_array[] =
 405 {
 406   B("and",      CPP_AND_AND),
 407   B("and_eq",   CPP_AND_EQ),
 408   B("bitand",   CPP_AND),
 409   B("bitor",    CPP_OR),
 410   B("compl",    CPP_COMPL),
 411   B("not",      CPP_NOT),
 412   B("not_eq",   CPP_NOT_EQ),
 413   B("or",       CPP_OR_OR),
 414   B("or_eq",    CPP_OR_EQ),
 415   B("xor",      CPP_XOR),
 416   B("xor_eq",   CPP_XOR_EQ)
 417 };
 418 #undef B
 419
 420 /* Mark the C++ named operators in the hash table.  */
 421 static void
 422 mark_named_operators (cpp_reader *pfile, int flags)
 423 {
 424   const struct builtin_operator *b;
 425
 426   for (b = operator_array;
 427        b < (operator_array + ARRAY_SIZE (operator_array));
 428        b++)
 429     {
 430       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 431       hp->flags |= flags;
 432       hp->is_directive = 0;
 433       hp->directive_index = b->value;
 434     }
 435 }
 436
 437 /* Helper function of cpp_type2name. Return the string associated with
 438    named operator TYPE.  */
 439 const char *
 440 cpp_named_operator2name (enum cpp_ttype type)
 441 {
 442   const struct builtin_operator *b;
 443
 444   for (b = operator_array;
 445        b < (operator_array + ARRAY_SIZE (operator_array));
 446        b++)
 447     {
 448       if (type == b->value)
 449         return (const char *) b->name;
 450     }
 451
 452   return NULL;
 453 }
 454
 455 void
 456 cpp_init_special_builtins (cpp_reader *pfile)
 457 {
 458   const struct builtin_macro *b;
 459   size_t n = ARRAY_SIZE (builtin_array);
 460
 461   if (CPP_OPTION (pfile, traditional))
 462     n -= 2;
 463   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 464            || CPP_OPTION (pfile, std))
 465     n--;
 466
 467   for (b = builtin_array; b < builtin_array + n; b++)
 468     {
 469       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 470       hp->type = NT_MACRO;
 471       hp->flags |= NODE_BUILTIN;
 472       if (b->always_warn_if_redefined)
 473         hp->flags |= NODE_WARN;
 474       hp->value.builtin = (enum cpp_builtin_type) b->value;
 475     }
 476 }
 477
 478 /* Read the builtins table above and enter them, and language-specific
 479    macros, into the hash table.  HOSTED is true if this is a hosted
 480    environment.  */
 481 void
 482 cpp_init_builtins (cpp_reader *pfile, int hosted)
 483 {
 484   cpp_init_special_builtins (pfile);
 485
 486   if (!CPP_OPTION (pfile, traditional)
 487       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 488           || CPP_OPTION (pfile, std)))
 489     _cpp_define_builtin (pfile, "__STDC__ 1");
 490
 491   if (CPP_OPTION (pfile, cplusplus))
 492     {
 493       if (CPP_OPTION (pfile, lang) == CLK_CXX1Z
 494           || CPP_OPTION (pfile, lang) == CLK_GNUCXX1Z)
 495         _cpp_define_builtin (pfile, "__cplusplus 201500L");
 496       else if (CPP_OPTION (pfile, lang) == CLK_CXX14
 497           || CPP_OPTION (pfile, lang) == CLK_GNUCXX14)
 498         _cpp_define_builtin (pfile, "__cplusplus 201402L");
 499       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 500                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 501         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 502       else
 503         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 504     }
 505   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 506     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 507   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 508     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 509   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 510            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 511     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 512   else if (CPP_OPTION (pfile, c99))
 513     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 514
 515   if (CPP_OPTION (pfile, uliterals)
 516       && !(CPP_OPTION (pfile, cplusplus)
 517            && (CPP_OPTION (pfile, lang) == CLK_GNUCXX
 518             || CPP_OPTION (pfile, lang) == CLK_CXX98)))
 519     {
 520       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 521       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 522     }
 523
 524   if (hosted)
 525     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 526   else
 527     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 528
 529   if (CPP_OPTION (pfile, objc))
 530     _cpp_define_builtin (pfile, "__OBJC__ 1");
 531 }
 532
 533 /* Sanity-checks are dependent on command-line options, so it is
 534    called as a subroutine of cpp_read_main_file ().  */
 535 #if ENABLE_CHECKING
 536 static void sanity_checks (cpp_reader *);
 537 static void sanity_checks (cpp_reader *pfile)
 538 {
 539   cppchar_t test = 0;
 540   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 541
 542   /* Sanity checks for assumptions about CPP arithmetic and target
 543      type precisions made by cpplib.  */
 544   test--;
 545   if (test < 1)
 546     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 547
 548   if (CPP_OPTION (pfile, precision) > max_precision)
 549     cpp_error (pfile, CPP_DL_ICE,
 550                "preprocessor arithmetic has maximum precision of %lu bits;"
 551                " target requires %lu bits",
 552                (unsigned long) max_precision,
 553                (unsigned long) CPP_OPTION (pfile, precision));
 554
 555   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 556     cpp_error (pfile, CPP_DL_ICE,
 557                "CPP arithmetic must be at least as precise as a target int");
 558
 559   if (CPP_OPTION (pfile, char_precision) < 8)
 560     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 561
 562   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 563     cpp_error (pfile, CPP_DL_ICE,
 564                "target wchar_t is narrower than target char");
 565
 566   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 567     cpp_error (pfile, CPP_DL_ICE,
 568                "target int is narrower than target char");
 569
 570   /* This is assumed in eval_token() and could be fixed if necessary.  */
 571   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 572     cpp_error (pfile, CPP_DL_ICE,
 573                "CPP half-integer narrower than CPP character");
 574
 575   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 576     cpp_error (pfile, CPP_DL_ICE,
 577                "CPP on this host cannot handle wide character constants over"
 578                " %lu bits, but the target requires %lu bits",
 579                (unsigned long) BITS_PER_CPPCHAR_T,
 580                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 581 }
 582 #else
 583 # define sanity_checks(PFILE)
 584 #endif
 585
 586 /* This is called after options have been parsed, and partially
 587    processed.  */
 588 void
 589 cpp_post_options (cpp_reader *pfile)
 590 {
 591   int flags;
 592
 593   sanity_checks (pfile);
 594
 595   post_options (pfile);
 596
 597   /* Mark named operators before handling command line macros.  */
 598   flags = 0;
 599   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 600     flags |= NODE_OPERATOR;
 601   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 602     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 603   if (flags != 0)
 604     mark_named_operators (pfile, flags);
 605 }
 606
 607 /* Setup for processing input from the file named FNAME, or stdin if
 608    it is the empty string.  Return the original filename
 609    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 610 const char *
 611 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 612 {
 613   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 614     {
 615       if (!pfile->deps)
 616         pfile->deps = deps_init ();
 617
 618       /* Set the default target (if there is none already).  */
 619       deps_add_default_target (pfile->deps, fname);
 620     }
 621
 622   pfile->main_file
 623     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false);
 624   if (_cpp_find_failed (pfile->main_file))
 625     return NULL;
 626
 627   _cpp_stack_file (pfile, pfile->main_file, false);
 628
 629   /* For foo.i, read the original filename foo.c now, for the benefit
 630      of the front ends.  */
 631   if (CPP_OPTION (pfile, preprocessed))
 632     {
 633       read_original_filename (pfile);
 634       fname =
 635         ORDINARY_MAP_FILE_NAME
 636         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 637     }
 638   return fname;
 639 }
 640
 641 /* For preprocessed files, if the first tokens are of the form # NUM.
 642    handle the directive so we know the original file name.  This will
 643    generate file_change callbacks, which the front ends must handle
 644    appropriately given their state of initialization.  */
 645 static void
 646 read_original_filename (cpp_reader *pfile)
 647 {
 648   const cpp_token *token, *token1;
 649
 650   /* Lex ahead; if the first tokens are of the form # NUM, then
 651      process the directive, otherwise back up.  */
 652   token = _cpp_lex_direct (pfile);
 653   if (token->type == CPP_HASH)
 654     {
 655       pfile->state.in_directive = 1;
 656       token1 = _cpp_lex_direct (pfile);
 657       _cpp_backup_tokens (pfile, 1);
 658       pfile->state.in_directive = 0;
 659
 660       /* If it's a #line directive, handle it.  */
 661       if (token1->type == CPP_NUMBER
 662           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 663         {
 664           read_original_directory (pfile);
 665           return;
 666         }
 667     }
 668
 669   /* Backup as if nothing happened.  */
 670   _cpp_backup_tokens (pfile, 1);
 671 }
 672
 673 /* For preprocessed files, if the tokens following the first filename
 674    line is of the form # <line> "/path/name//", handle the
 675    directive so we know the original current directory.  */
 676 static void
 677 read_original_directory (cpp_reader *pfile)
 678 {
 679   const cpp_token *hash, *token;
 680
 681   /* Lex ahead; if the first tokens are of the form # NUM, then
 682      process the directive, otherwise back up.  */
 683   hash = _cpp_lex_direct (pfile);
 684   if (hash->type != CPP_HASH)
 685     {
 686       _cpp_backup_tokens (pfile, 1);
 687       return;
 688     }
 689
 690   token = _cpp_lex_direct (pfile);
 691
 692   if (token->type != CPP_NUMBER)
 693     {
 694       _cpp_backup_tokens (pfile, 2);
 695       return;
 696     }
 697
 698   token = _cpp_lex_direct (pfile);
 699
 700   if (token->type != CPP_STRING
 701       || ! (token->val.str.len >= 5
 702             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 703             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 704     {
 705       _cpp_backup_tokens (pfile, 3);
 706       return;
 707     }
 708
 709   if (pfile->cb.dir_change)
 710     {
 711       char *debugdir = (char *) alloca (token->val.str.len - 3);
 712
 713       memcpy (debugdir, (const char *) token->val.str.text + 1,
 714               token->val.str.len - 4);
 715       debugdir[token->val.str.len - 4] = '\0';
 716
 717       pfile->cb.dir_change (pfile, debugdir);
 718     }
 719 }
 720
 721 /* This is called at the end of preprocessing.  It pops the last
 722    buffer and writes dependency output.
 723
 724    Maybe it should also reset state, such that you could call
 725    cpp_start_read with a new filename to restart processing.  */
 726 void
 727 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 728 {
 729   /* Warn about unused macros before popping the final buffer.  */
 730   if (CPP_OPTION (pfile, warn_unused_macros))
 731     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 732
 733   /* lex.c leaves the final buffer on the stack.  This it so that
 734      it returns an unending stream of CPP_EOFs to the client.  If we
 735      popped the buffer, we'd dereference a NULL buffer pointer and
 736      segfault.  It's nice to allow the client to do worry-free excess
 737      cpp_get_token calls.  */
 738   while (pfile->buffer)
 739     _cpp_pop_buffer (pfile);
 740
 741   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 742       && deps_stream)
 743     {
 744       deps_write (pfile->deps, deps_stream, 72);
 745
 746       if (CPP_OPTION (pfile, deps.phony_targets))
 747         deps_phony_targets (pfile->deps, deps_stream);
 748     }
 749
 750   /* Report on headers that could use multiple include guards.  */
 751   if (CPP_OPTION (pfile, print_include_names))
 752     _cpp_report_missing_guards (pfile);
 753 }
 754
 755 static void
 756 post_options (cpp_reader *pfile)
 757 {
 758   /* -Wtraditional is not useful in C++ mode.  */
 759   if (CPP_OPTION (pfile, cplusplus))
 760     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 761
 762   /* Permanently disable macro expansion if we are rescanning
 763      preprocessed text.  Read preprocesed source in ISO mode.  */
 764   if (CPP_OPTION (pfile, preprocessed))
 765     {
 766       if (!CPP_OPTION (pfile, directives_only))
 767         pfile->state.prevent_expansion = 1;
 768       CPP_OPTION (pfile, traditional) = 0;
 769     }
 770
 771   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 772     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 773
 774   if (CPP_OPTION (pfile, traditional))
 775     {
 776       CPP_OPTION (pfile, trigraphs) = 0;
 777       CPP_OPTION (pfile, warn_trigraphs) = 0;
 778     }
 779 }