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   char digit_separators;
  88 };
  89
  90 static const struct lang_flags lang_defaults[] =
  91 { /*              c99 c++ xnum xid std  //   digr ulit rlit udlit bin_cst dig_sep */
  92   /* GNUC89   */  { 0,  0,  1,   0,  0,   1,   1,   0,   0,   0,    0,      0 },
  93   /* GNUC99   */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,   0,    0,      0 },
  94   /* GNUC11   */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,   0,    0,      0 },
  95   /* STDC89   */  { 0,  0,  0,   0,  1,   0,   0,   0,   0,   0,    0,      0 },
  96   /* STDC94   */  { 0,  0,  0,   0,  1,   0,   1,   0,   0,   0,    0,      0 },
  97   /* STDC99   */  { 1,  0,  1,   0,  1,   1,   1,   0,   0,   0,    0,      0 },
  98   /* STDC11   */  { 1,  0,  1,   0,  1,   1,   1,   1,   0,   0,    0,      0 },
  99   /* UPC      */  { 1,  0,  1,   0,  0,   1,   1,   1,   1,   0,    0,      0 },
 100   /* GNUCXX   */  { 0,  1,  1,   0,  0,   1,   1,   0,   0,   0,    0,      0 },
 101   /* CXX98    */  { 0,  1,  1,   0,  1,   1,   1,   0,   0,   0,    0,      0 },
 102   /* GNUCXX11 */  { 1,  1,  1,   0,  0,   1,   1,   1,   1,   1,    0,      0 },
 103   /* CXX11    */  { 1,  1,  1,   0,  1,   1,   1,   1,   1,   1,    0,      0 },
 104   /* GNUCXX1Y */  { 1,  1,  1,   0,  0,   1,   1,   1,   1,   1,    1,      1 },
 105   /* CXX1Y    */  { 1,  1,  1,   0,  1,   1,   1,   1,   1,   1,    1,      1 },
 106   /* ASM      */  { 0,  0,  1,   0,  0,   1,   0,   0,   0,   0,    0,      0 }
 107   /* xid should be 1 for GNUC99, STDC99, GNUCXX, CXX98, GNUCXX11, CXX11,
 108      GNUCXX1Y, and CXX1Y when no longer experimental (when all uses of
 109      identifiers in the compiler have been audited for correct handling
 110      of extended identifiers).  */
 111 };
 112
 113 /* Sets internal flags correctly for a given language.  */
 114 void
 115 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 116 {
 117   const struct lang_flags *l = &lang_defaults[(int) lang];
 118
 119   CPP_OPTION (pfile, lang) = lang;
 120
 121   CPP_OPTION (pfile, c99)                        = l->c99;
 122   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 123   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 124   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 125   CPP_OPTION (pfile, std)                        = l->std;
 126   CPP_OPTION (pfile, trigraphs)                  = l->std;
 127   CPP_OPTION (pfile, cplusplus_comments)         = l->cplusplus_comments;
 128   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 129   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 130   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 131   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 132   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 133   CPP_OPTION (pfile, digit_separators)           = l->digit_separators;
 134 }
 135
 136 /* Initialize library global state.  */
 137 static void
 138 init_library (void)
 139 {
 140   static int initialized = 0;
 141
 142   if (! initialized)
 143     {
 144       initialized = 1;
 145
 146       _cpp_init_lexer ();
 147
 148       /* Set up the trigraph map.  This doesn't need to do anything if
 149          we were compiled with a compiler that supports C99 designated
 150          initializers.  */
 151       init_trigraph_map ();
 152
 153 #ifdef ENABLE_NLS
 154        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 155 #endif
 156     }
 157 }
 158
 159 /* Initialize a cpp_reader structure.  */
 160 cpp_reader *
 161 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 162                    struct line_maps *line_table)
 163 {
 164   cpp_reader *pfile;
 165
 166   /* Initialize this instance of the library if it hasn't been already.  */
 167   init_library ();
 168
 169   pfile = XCNEW (cpp_reader);
 170   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 171
 172   cpp_set_lang (pfile, lang);
 173   CPP_OPTION (pfile, warn_multichar) = 1;
 174   CPP_OPTION (pfile, discard_comments) = 1;
 175   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 176   CPP_OPTION (pfile, tabstop) = 8;
 177   CPP_OPTION (pfile, operator_names) = 1;
 178   CPP_OPTION (pfile, warn_trigraphs) = 2;
 179   CPP_OPTION (pfile, warn_endif_labels) = 1;
 180   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 181   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 182   CPP_OPTION (pfile, dollars_in_ident) = 1;
 183   CPP_OPTION (pfile, warn_dollars) = 1;
 184   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 185   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 186   /* By default, track locations of tokens resulting from macro
 187      expansion.  The '2' means, track the locations with the highest
 188      accuracy.  Read the comments for struct
 189      cpp_options::track_macro_expansion to learn about the other
 190      values.  */
 191   CPP_OPTION (pfile, track_macro_expansion) = 2;
 192   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 193   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 194   CPP_OPTION (pfile, canonical_system_headers)
 195       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 196   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 197   CPP_OPTION (pfile, warn_date_time) = 0;
 198
 199   /* Default CPP arithmetic to something sensible for the host for the
 200      benefit of dumb users like fix-header.  */
 201   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 202   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 203   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 204   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 205   CPP_OPTION (pfile, unsigned_char) = 0;
 206   CPP_OPTION (pfile, unsigned_wchar) = 1;
 207   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 208
 209   /* Default to no charset conversion.  */
 210   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 211   CPP_OPTION (pfile, wide_charset) = 0;
 212
 213   /* Default the input character set to UTF-8.  */
 214   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 215
 216   /* A fake empty "directory" used as the starting point for files
 217      looked up without a search path.  Name cannot be '/' because we
 218      don't want to prepend anything at all to filenames using it.  All
 219      other entries are correct zero-initialized.  */
 220   pfile->no_search_path.name = (char *) "";
 221
 222   /* Initialize the line map.  */
 223   pfile->line_table = line_table;
 224
 225   /* Initialize lexer state.  */
 226   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 227
 228   /* Set up static tokens.  */
 229   pfile->avoid_paste.type = CPP_PADDING;
 230   pfile->avoid_paste.val.source = NULL;
 231   pfile->eof.type = CPP_EOF;
 232   pfile->eof.flags = 0;
 233
 234   /* Create a token buffer for the lexer.  */
 235   _cpp_init_tokenrun (&pfile->base_run, 250);
 236   pfile->cur_run = &pfile->base_run;
 237   pfile->cur_token = pfile->base_run.base;
 238
 239   /* Initialize the base context.  */
 240   pfile->context = &pfile->base_context;
 241   pfile->base_context.c.macro = 0;
 242   pfile->base_context.prev = pfile->base_context.next = 0;
 243
 244   /* Aligned and unaligned storage.  */
 245   pfile->a_buff = _cpp_get_buff (pfile, 0);
 246   pfile->u_buff = _cpp_get_buff (pfile, 0);
 247
 248   /* Initialize table for push_macro/pop_macro.  */
 249   pfile->pushed_macros = 0;
 250
 251   /* Do not force token locations by default.  */
 252   pfile->forced_token_location_p = NULL;
 253
 254   /* The expression parser stack.  */
 255   _cpp_expand_op_stack (pfile);
 256
 257   /* Initialize the buffer obstack.  */
 258   _obstack_begin (&pfile->buffer_ob, 0, 0,
 259                   (void *(*) (long)) xmalloc,
 260                   (void (*) (void *)) free);
 261
 262   _cpp_init_files (pfile);
 263
 264   _cpp_init_hashtable (pfile, table);
 265
 266   return pfile;
 267 }
 268
 269 /* Set the line_table entry in PFILE.  This is called after reading a
 270    PCH file, as the old line_table will be incorrect.  */
 271 void
 272 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 273 {
 274   pfile->line_table = line_table;
 275 }
 276
 277 /* Free resources used by PFILE.  Accessing PFILE after this function
 278    returns leads to undefined behavior.  Returns the error count.  */
 279 void
 280 cpp_destroy (cpp_reader *pfile)
 281 {
 282   cpp_context *context, *contextn;
 283   struct def_pragma_macro *pmacro;
 284   tokenrun *run, *runn;
 285   int i;
 286
 287   free (pfile->op_stack);
 288
 289   while (CPP_BUFFER (pfile) != NULL)
 290     _cpp_pop_buffer (pfile);
 291
 292   free (pfile->out.base);
 293
 294   if (pfile->macro_buffer)
 295     {
 296       free (pfile->macro_buffer);
 297       pfile->macro_buffer = NULL;
 298       pfile->macro_buffer_len = 0;
 299     }
 300
 301   if (pfile->deps)
 302     deps_free (pfile->deps);
 303   obstack_free (&pfile->buffer_ob, 0);
 304
 305   _cpp_destroy_hashtable (pfile);
 306   _cpp_cleanup_files (pfile);
 307   _cpp_destroy_iconv (pfile);
 308
 309   _cpp_free_buff (pfile->a_buff);
 310   _cpp_free_buff (pfile->u_buff);
 311   _cpp_free_buff (pfile->free_buffs);
 312
 313   for (run = &pfile->base_run; run; run = runn)
 314     {
 315       runn = run->next;
 316       free (run->base);
 317       if (run != &pfile->base_run)
 318         free (run);
 319     }
 320
 321   for (context = pfile->base_context.next; context; context = contextn)
 322     {
 323       contextn = context->next;
 324       free (context);
 325     }
 326
 327   if (pfile->comments.entries)
 328     {
 329       for (i = 0; i < pfile->comments.count; i++)
 330         free (pfile->comments.entries[i].comment);
 331
 332       free (pfile->comments.entries);
 333     }
 334   if (pfile->pushed_macros)
 335     {
 336       do
 337         {
 338           pmacro = pfile->pushed_macros;
 339           pfile->pushed_macros = pmacro->next;
 340           free (pmacro->name);
 341           free (pmacro);
 342         }
 343       while (pfile->pushed_macros);
 344     }
 345
 346   free (pfile);
 347 }
 348
 349 /* This structure defines one built-in identifier.  A node will be
 350    entered in the hash table under the name NAME, with value VALUE.
 351
 352    There are two tables of these.  builtin_array holds all the
 353    "builtin" macros: these are handled by builtin_macro() in
 354    macro.c.  Builtin is somewhat of a misnomer -- the property of
 355    interest is that these macros require special code to compute their
 356    expansions.  The value is a "cpp_builtin_type" enumerator.
 357
 358    operator_array holds the C++ named operators.  These are keywords
 359    which act as aliases for punctuators.  In C++, they cannot be
 360    altered through #define, and #if recognizes them as operators.  In
 361    C, these are not entered into the hash table at all (but see
 362    <iso646.h>).  The value is a token-type enumerator.  */
 363 struct builtin_macro
 364 {
 365   const uchar *const name;
 366   const unsigned short len;
 367   const unsigned short value;
 368   const bool always_warn_if_redefined;
 369 };
 370
 371 #define B(n, t, f)    { DSC(n), t, f }
 372 static const struct builtin_macro builtin_array[] =
 373 {
 374   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 375   B("__TIME__",          BT_TIME,          false),
 376   B("__DATE__",          BT_DATE,          false),
 377   B("__FILE__",          BT_FILE,          false),
 378   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 379   B("__LINE__",          BT_SPECLINE,      true),
 380   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 381   B("__COUNTER__",       BT_COUNTER,       true),
 382   /* Keep builtins not used for -traditional-cpp at the end, and
 383      update init_builtins() if any more are added.  */
 384   B("_Pragma",           BT_PRAGMA,        true),
 385   B("__STDC__",          BT_STDC,          true),
 386 };
 387 #undef B
 388
 389 struct builtin_operator
 390 {
 391   const uchar *const name;
 392   const unsigned short len;
 393   const unsigned short value;
 394 };
 395
 396 #define B(n, t)    { DSC(n), t }
 397 static const struct builtin_operator operator_array[] =
 398 {
 399   B("and",      CPP_AND_AND),
 400   B("and_eq",   CPP_AND_EQ),
 401   B("bitand",   CPP_AND),
 402   B("bitor",    CPP_OR),
 403   B("compl",    CPP_COMPL),
 404   B("not",      CPP_NOT),
 405   B("not_eq",   CPP_NOT_EQ),
 406   B("or",       CPP_OR_OR),
 407   B("or_eq",    CPP_OR_EQ),
 408   B("xor",      CPP_XOR),
 409   B("xor_eq",   CPP_XOR_EQ)
 410 };
 411 #undef B
 412
 413 /* Mark the C++ named operators in the hash table.  */
 414 static void
 415 mark_named_operators (cpp_reader *pfile, int flags)
 416 {
 417   const struct builtin_operator *b;
 418
 419   for (b = operator_array;
 420        b < (operator_array + ARRAY_SIZE (operator_array));
 421        b++)
 422     {
 423       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 424       hp->flags |= flags;
 425       hp->is_directive = 0;
 426       hp->directive_index = b->value;
 427     }
 428 }
 429
 430 /* Helper function of cpp_type2name. Return the string associated with
 431    named operator TYPE.  */
 432 const char *
 433 cpp_named_operator2name (enum cpp_ttype type)
 434 {
 435   const struct builtin_operator *b;
 436
 437   for (b = operator_array;
 438        b < (operator_array + ARRAY_SIZE (operator_array));
 439        b++)
 440     {
 441       if (type == b->value)
 442         return (const char *) b->name;
 443     }
 444
 445   return NULL;
 446 }
 447
 448 void
 449 cpp_init_special_builtins (cpp_reader *pfile)
 450 {
 451   const struct builtin_macro *b;
 452   size_t n = ARRAY_SIZE (builtin_array);
 453
 454   if (CPP_OPTION (pfile, traditional))
 455     n -= 2;
 456   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 457            || CPP_OPTION (pfile, std))
 458     n--;
 459
 460   for (b = builtin_array; b < builtin_array + n; b++)
 461     {
 462       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 463       hp->type = NT_MACRO;
 464       hp->flags |= NODE_BUILTIN;
 465       if (b->always_warn_if_redefined
 466           || CPP_OPTION (pfile, warn_builtin_macro_redefined))
 467         hp->flags |= NODE_WARN;
 468       hp->value.builtin = (enum cpp_builtin_type) b->value;
 469     }
 470 }
 471
 472 /* Read the builtins table above and enter them, and language-specific
 473    macros, into the hash table.  HOSTED is true if this is a hosted
 474    environment.  */
 475 void
 476 cpp_init_builtins (cpp_reader *pfile, int hosted)
 477 {
 478   cpp_init_special_builtins (pfile);
 479
 480   if (!CPP_OPTION (pfile, traditional)
 481       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 482           || CPP_OPTION (pfile, std)))
 483     _cpp_define_builtin (pfile, "__STDC__ 1");
 484
 485   if (CPP_OPTION (pfile, cplusplus))
 486     {
 487       if (CPP_OPTION (pfile, lang) == CLK_CXX1Y
 488           || CPP_OPTION (pfile, lang) == CLK_GNUCXX1Y)
 489         _cpp_define_builtin (pfile, "__cplusplus 201300L");
 490       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 491                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 492         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 493       else
 494         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 495     }
 496   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 497     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 498   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 499     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 500   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 501            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 502     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 503   else if (CPP_OPTION (pfile, c99))
 504     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 505
 506   if (CPP_OPTION (pfile, uliterals)
 507       && !CPP_OPTION (pfile, cplusplus))
 508     {
 509       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 510       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 511     }
 512
 513   if (hosted)
 514     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 515   else
 516     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 517
 518   if (CPP_OPTION (pfile, objc))
 519     _cpp_define_builtin (pfile, "__OBJC__ 1");
 520 }
 521
 522 /* Sanity-checks are dependent on command-line options, so it is
 523    called as a subroutine of cpp_read_main_file ().  */
 524 #if ENABLE_CHECKING
 525 static void sanity_checks (cpp_reader *);
 526 static void sanity_checks (cpp_reader *pfile)
 527 {
 528   cppchar_t test = 0;
 529   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 530
 531   /* Sanity checks for assumptions about CPP arithmetic and target
 532      type precisions made by cpplib.  */
 533   test--;
 534   if (test < 1)
 535     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 536
 537   if (CPP_OPTION (pfile, precision) > max_precision)
 538     cpp_error (pfile, CPP_DL_ICE,
 539                "preprocessor arithmetic has maximum precision of %lu bits;"
 540                " target requires %lu bits",
 541                (unsigned long) max_precision,
 542                (unsigned long) CPP_OPTION (pfile, precision));
 543
 544   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 545     cpp_error (pfile, CPP_DL_ICE,
 546                "CPP arithmetic must be at least as precise as a target int");
 547
 548   if (CPP_OPTION (pfile, char_precision) < 8)
 549     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 550
 551   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 552     cpp_error (pfile, CPP_DL_ICE,
 553                "target wchar_t is narrower than target char");
 554
 555   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 556     cpp_error (pfile, CPP_DL_ICE,
 557                "target int is narrower than target char");
 558
 559   /* This is assumed in eval_token() and could be fixed if necessary.  */
 560   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 561     cpp_error (pfile, CPP_DL_ICE,
 562                "CPP half-integer narrower than CPP character");
 563
 564   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 565     cpp_error (pfile, CPP_DL_ICE,
 566                "CPP on this host cannot handle wide character constants over"
 567                " %lu bits, but the target requires %lu bits",
 568                (unsigned long) BITS_PER_CPPCHAR_T,
 569                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 570 }
 571 #else
 572 # define sanity_checks(PFILE)
 573 #endif
 574
 575 /* This is called after options have been parsed, and partially
 576    processed.  */
 577 void
 578 cpp_post_options (cpp_reader *pfile)
 579 {
 580   int flags;
 581
 582   sanity_checks (pfile);
 583
 584   post_options (pfile);
 585
 586   /* Mark named operators before handling command line macros.  */
 587   flags = 0;
 588   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 589     flags |= NODE_OPERATOR;
 590   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 591     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 592   if (flags != 0)
 593     mark_named_operators (pfile, flags);
 594 }
 595
 596 /* Setup for processing input from the file named FNAME, or stdin if
 597    it is the empty string.  Return the original filename
 598    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 599 const char *
 600 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 601 {
 602   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 603     {
 604       if (!pfile->deps)
 605         pfile->deps = deps_init ();
 606
 607       /* Set the default target (if there is none already).  */
 608       deps_add_default_target (pfile->deps, fname);
 609     }
 610
 611   pfile->main_file
 612     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false);
 613   if (_cpp_find_failed (pfile->main_file))
 614     return NULL;
 615
 616   _cpp_stack_file (pfile, pfile->main_file, false);
 617
 618   /* For foo.i, read the original filename foo.c now, for the benefit
 619      of the front ends.  */
 620   if (CPP_OPTION (pfile, preprocessed))
 621     {
 622       read_original_filename (pfile);
 623       fname =
 624         ORDINARY_MAP_FILE_NAME
 625         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 626     }
 627   return fname;
 628 }
 629
 630 /* For preprocessed files, if the first tokens are of the form # NUM.
 631    handle the directive so we know the original file name.  This will
 632    generate file_change callbacks, which the front ends must handle
 633    appropriately given their state of initialization.  */
 634 static void
 635 read_original_filename (cpp_reader *pfile)
 636 {
 637   const cpp_token *token, *token1;
 638
 639   /* Lex ahead; if the first tokens are of the form # NUM, then
 640      process the directive, otherwise back up.  */
 641   token = _cpp_lex_direct (pfile);
 642   if (token->type == CPP_HASH)
 643     {
 644       pfile->state.in_directive = 1;
 645       token1 = _cpp_lex_direct (pfile);
 646       _cpp_backup_tokens (pfile, 1);
 647       pfile->state.in_directive = 0;
 648
 649       /* If it's a #line directive, handle it.  */
 650       if (token1->type == CPP_NUMBER
 651           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 652         {
 653           read_original_directory (pfile);
 654           return;
 655         }
 656     }
 657
 658   /* Backup as if nothing happened.  */
 659   _cpp_backup_tokens (pfile, 1);
 660 }
 661
 662 /* For preprocessed files, if the tokens following the first filename
 663    line is of the form # <line> "/path/name//", handle the
 664    directive so we know the original current directory.  */
 665 static void
 666 read_original_directory (cpp_reader *pfile)
 667 {
 668   const cpp_token *hash, *token;
 669
 670   /* Lex ahead; if the first tokens are of the form # NUM, then
 671      process the directive, otherwise back up.  */
 672   hash = _cpp_lex_direct (pfile);
 673   if (hash->type != CPP_HASH)
 674     {
 675       _cpp_backup_tokens (pfile, 1);
 676       return;
 677     }
 678
 679   token = _cpp_lex_direct (pfile);
 680
 681   if (token->type != CPP_NUMBER)
 682     {
 683       _cpp_backup_tokens (pfile, 2);
 684       return;
 685     }
 686
 687   token = _cpp_lex_direct (pfile);
 688
 689   if (token->type != CPP_STRING
 690       || ! (token->val.str.len >= 5
 691             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 692             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 693     {
 694       _cpp_backup_tokens (pfile, 3);
 695       return;
 696     }
 697
 698   if (pfile->cb.dir_change)
 699     {
 700       char *debugdir = (char *) alloca (token->val.str.len - 3);
 701
 702       memcpy (debugdir, (const char *) token->val.str.text + 1,
 703               token->val.str.len - 4);
 704       debugdir[token->val.str.len - 4] = '\0';
 705
 706       pfile->cb.dir_change (pfile, debugdir);
 707     }
 708 }
 709
 710 /* This is called at the end of preprocessing.  It pops the last
 711    buffer and writes dependency output.
 712
 713    Maybe it should also reset state, such that you could call
 714    cpp_start_read with a new filename to restart processing.  */
 715 void
 716 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 717 {
 718   /* Warn about unused macros before popping the final buffer.  */
 719   if (CPP_OPTION (pfile, warn_unused_macros))
 720     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 721
 722   /* lex.c leaves the final buffer on the stack.  This it so that
 723      it returns an unending stream of CPP_EOFs to the client.  If we
 724      popped the buffer, we'd dereference a NULL buffer pointer and
 725      segfault.  It's nice to allow the client to do worry-free excess
 726      cpp_get_token calls.  */
 727   while (pfile->buffer)
 728     _cpp_pop_buffer (pfile);
 729
 730   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 731       && deps_stream)
 732     {
 733       deps_write (pfile->deps, deps_stream, 72);
 734
 735       if (CPP_OPTION (pfile, deps.phony_targets))
 736         deps_phony_targets (pfile->deps, deps_stream);
 737     }
 738
 739   /* Report on headers that could use multiple include guards.  */
 740   if (CPP_OPTION (pfile, print_include_names))
 741     _cpp_report_missing_guards (pfile);
 742 }
 743
 744 static void
 745 post_options (cpp_reader *pfile)
 746 {
 747   /* -Wtraditional is not useful in C++ mode.  */
 748   if (CPP_OPTION (pfile, cplusplus))
 749     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 750
 751   /* Permanently disable macro expansion if we are rescanning
 752      preprocessed text.  Read preprocesed source in ISO mode.  */
 753   if (CPP_OPTION (pfile, preprocessed))
 754     {
 755       if (!CPP_OPTION (pfile, directives_only))
 756         pfile->state.prevent_expansion = 1;
 757       CPP_OPTION (pfile, traditional) = 0;
 758     }
 759
 760   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 761     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 762
 763   if (CPP_OPTION (pfile, traditional))
 764     {
 765       CPP_OPTION (pfile, cplusplus_comments) = 0;
 766
 767       CPP_OPTION (pfile, trigraphs) = 0;
 768       CPP_OPTION (pfile, warn_trigraphs) = 0;
 769     }
 770 }