libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2019 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   char va_opt;
  95 };
  96
  97 static const struct lang_flags lang_defaults[] =
  98 { /*              c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt */
  99   /* GNUC89   */  { 0,  0,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0,      1 },
 100   /* GNUC99   */  { 1,  0,  1,  1,  0,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1 },
 101   /* GNUC11   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1 },
 102   /* GNUC17   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1 },
 103   /* GNUC2X   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0,      1 },
 104   /* STDC89   */  { 0,  0,  0,  0,  0,  1,  0,   0,   0,   0,    0,     0,     1,   0,      0 },
 105   /* STDC94   */  { 0,  0,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0 },
 106   /* STDC99   */  { 1,  0,  1,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0 },
 107   /* STDC11   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0 },
 108   /* STDC17   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0 },
 109   /* STDC2X   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0,      0 },
 110   /* GNUCXX   */  { 0,  1,  1,  1,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0,      1 },
 111   /* CXX98    */  { 0,  1,  0,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0,      0 },
 112   /* GNUCXX11 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    0,     0,     0,   0,      1 },
 113   /* CXX11    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    0,     0,     1,   0,      0 },
 114   /* GNUCXX14 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   0,      1 },
 115   /* CXX14    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    1,     1,     1,   0,      0 },
 116   /* GNUCXX17 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1 },
 117   /* CXX17    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      0 },
 118   /* GNUCXX2A */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1,      1 },
 119   /* CXX2A    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1,      1 },
 120   /* ASM      */  { 0,  0,  1,  0,  0,  0,  0,   0,   0,   0,    0,     0,     0,   0,      0 }
 121 };
 122
 123 /* Sets internal flags correctly for a given language.  */
 124 void
 125 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 126 {
 127   const struct lang_flags *l = &lang_defaults[(int) lang];
 128
 129   CPP_OPTION (pfile, lang) = lang;
 130
 131   CPP_OPTION (pfile, c99)                        = l->c99;
 132   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 133   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 134   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 135   CPP_OPTION (pfile, c11_identifiers)            = l->c11_identifiers;
 136   CPP_OPTION (pfile, std)                        = l->std;
 137   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 138   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 139   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 140   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 141   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 142   CPP_OPTION (pfile, digit_separators)           = l->digit_separators;
 143   CPP_OPTION (pfile, trigraphs)                  = l->trigraphs;
 144   CPP_OPTION (pfile, utf8_char_literals)         = l->utf8_char_literals;
 145   CPP_OPTION (pfile, va_opt)                     = l->va_opt;
 146 }
 147
 148 /* Initialize library global state.  */
 149 static void
 150 init_library (void)
 151 {
 152   static int initialized = 0;
 153
 154   if (! initialized)
 155     {
 156       initialized = 1;
 157
 158       _cpp_init_lexer ();
 159
 160       /* Set up the trigraph map.  This doesn't need to do anything if
 161          we were compiled with a compiler that supports C99 designated
 162          initializers.  */
 163       init_trigraph_map ();
 164
 165 #ifdef ENABLE_NLS
 166        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 167 #endif
 168     }
 169 }
 170
 171 /* Initialize a cpp_reader structure.  */
 172 cpp_reader *
 173 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 174                    class line_maps *line_table)
 175 {
 176   cpp_reader *pfile;
 177
 178   /* Initialize this instance of the library if it hasn't been already.  */
 179   init_library ();
 180
 181   pfile = XCNEW (cpp_reader);
 182   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 183
 184   cpp_set_lang (pfile, lang);
 185   CPP_OPTION (pfile, warn_multichar) = 1;
 186   CPP_OPTION (pfile, discard_comments) = 1;
 187   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 188   CPP_OPTION (pfile, max_include_depth) = 200;
 189   CPP_OPTION (pfile, tabstop) = 8;
 190   CPP_OPTION (pfile, operator_names) = 1;
 191   CPP_OPTION (pfile, warn_trigraphs) = 2;
 192   CPP_OPTION (pfile, warn_endif_labels) = 1;
 193   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
 194   CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0;
 195   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 196   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 197   CPP_OPTION (pfile, dollars_in_ident) = 1;
 198   CPP_OPTION (pfile, warn_dollars) = 1;
 199   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 200   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 201   CPP_OPTION (pfile, cpp_warn_implicit_fallthrough) = 0;
 202   /* By default, track locations of tokens resulting from macro
 203      expansion.  The '2' means, track the locations with the highest
 204      accuracy.  Read the comments for struct
 205      cpp_options::track_macro_expansion to learn about the other
 206      values.  */
 207   CPP_OPTION (pfile, track_macro_expansion) = 2;
 208   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 209   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 210   CPP_OPTION (pfile, canonical_system_headers)
 211       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 212   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 213   CPP_OPTION (pfile, warn_date_time) = 0;
 214
 215   /* Default CPP arithmetic to something sensible for the host for the
 216      benefit of dumb users like fix-header.  */
 217   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 218   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 219   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 220   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 221   CPP_OPTION (pfile, unsigned_char) = 0;
 222   CPP_OPTION (pfile, unsigned_wchar) = 1;
 223   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 224
 225   /* Default to no charset conversion.  */
 226   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 227   CPP_OPTION (pfile, wide_charset) = 0;
 228
 229   /* Default the input character set to UTF-8.  */
 230   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 231
 232   /* A fake empty "directory" used as the starting point for files
 233      looked up without a search path.  Name cannot be '/' because we
 234      don't want to prepend anything at all to filenames using it.  All
 235      other entries are correct zero-initialized.  */
 236   pfile->no_search_path.name = (char *) "";
 237
 238   /* Initialize the line map.  */
 239   pfile->line_table = line_table;
 240
 241   /* Initialize lexer state.  */
 242   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 243
 244   /* Set up static tokens.  */
 245   pfile->avoid_paste.type = CPP_PADDING;
 246   pfile->avoid_paste.val.source = NULL;
 247   pfile->eof.type = CPP_EOF;
 248   pfile->eof.flags = 0;
 249
 250   /* Create a token buffer for the lexer.  */
 251   _cpp_init_tokenrun (&pfile->base_run, 250);
 252   pfile->cur_run = &pfile->base_run;
 253   pfile->cur_token = pfile->base_run.base;
 254
 255   /* Initialize the base context.  */
 256   pfile->context = &pfile->base_context;
 257   pfile->base_context.c.macro = 0;
 258   pfile->base_context.prev = pfile->base_context.next = 0;
 259
 260   /* Aligned and unaligned storage.  */
 261   pfile->a_buff = _cpp_get_buff (pfile, 0);
 262   pfile->u_buff = _cpp_get_buff (pfile, 0);
 263
 264   /* Initialize table for push_macro/pop_macro.  */
 265   pfile->pushed_macros = 0;
 266
 267   /* Do not force token locations by default.  */
 268   pfile->forced_token_location = 0;
 269
 270   /* Initialize source_date_epoch to -2 (not yet set).  */
 271   pfile->source_date_epoch = (time_t) -2;
 272
 273   /* The expression parser stack.  */
 274   _cpp_expand_op_stack (pfile);
 275
 276   /* Initialize the buffer obstack.  */
 277   obstack_specify_allocation (&pfile->buffer_ob, 0, 0, xmalloc, free);
 278
 279   _cpp_init_files (pfile);
 280
 281   _cpp_init_hashtable (pfile, table);
 282
 283   return pfile;
 284 }
 285
 286 /* Set the line_table entry in PFILE.  This is called after reading a
 287    PCH file, as the old line_table will be incorrect.  */
 288 void
 289 cpp_set_line_map (cpp_reader *pfile, class line_maps *line_table)
 290 {
 291   pfile->line_table = line_table;
 292 }
 293
 294 /* Free resources used by PFILE.  Accessing PFILE after this function
 295    returns leads to undefined behavior.  Returns the error count.  */
 296 void
 297 cpp_destroy (cpp_reader *pfile)
 298 {
 299   cpp_context *context, *contextn;
 300   struct def_pragma_macro *pmacro;
 301   tokenrun *run, *runn;
 302   int i;
 303
 304   free (pfile->op_stack);
 305
 306   while (CPP_BUFFER (pfile) != NULL)
 307     _cpp_pop_buffer (pfile);
 308
 309   free (pfile->out.base);
 310
 311   if (pfile->macro_buffer)
 312     {
 313       free (pfile->macro_buffer);
 314       pfile->macro_buffer = NULL;
 315       pfile->macro_buffer_len = 0;
 316     }
 317
 318   if (pfile->deps)
 319     deps_free (pfile->deps);
 320   obstack_free (&pfile->buffer_ob, 0);
 321
 322   _cpp_destroy_hashtable (pfile);
 323   _cpp_cleanup_files (pfile);
 324   _cpp_destroy_iconv (pfile);
 325
 326   _cpp_free_buff (pfile->a_buff);
 327   _cpp_free_buff (pfile->u_buff);
 328   _cpp_free_buff (pfile->free_buffs);
 329
 330   for (run = &pfile->base_run; run; run = runn)
 331     {
 332       runn = run->next;
 333       free (run->base);
 334       if (run != &pfile->base_run)
 335         free (run);
 336     }
 337
 338   for (context = pfile->base_context.next; context; context = contextn)
 339     {
 340       contextn = context->next;
 341       free (context);
 342     }
 343
 344   if (pfile->comments.entries)
 345     {
 346       for (i = 0; i < pfile->comments.count; i++)
 347         free (pfile->comments.entries[i].comment);
 348
 349       free (pfile->comments.entries);
 350     }
 351   if (pfile->pushed_macros)
 352     {
 353       do
 354         {
 355           pmacro = pfile->pushed_macros;
 356           pfile->pushed_macros = pmacro->next;
 357           free (pmacro->name);
 358           free (pmacro);
 359         }
 360       while (pfile->pushed_macros);
 361     }
 362
 363   free (pfile);
 364 }
 365
 366 /* This structure defines one built-in identifier.  A node will be
 367    entered in the hash table under the name NAME, with value VALUE.
 368
 369    There are two tables of these.  builtin_array holds all the
 370    "builtin" macros: these are handled by builtin_macro() in
 371    macro.c.  Builtin is somewhat of a misnomer -- the property of
 372    interest is that these macros require special code to compute their
 373    expansions.  The value is a "cpp_builtin_type" enumerator.
 374
 375    operator_array holds the C++ named operators.  These are keywords
 376    which act as aliases for punctuators.  In C++, they cannot be
 377    altered through #define, and #if recognizes them as operators.  In
 378    C, these are not entered into the hash table at all (but see
 379    <iso646.h>).  The value is a token-type enumerator.  */
 380 struct builtin_macro
 381 {
 382   const uchar *const name;
 383   const unsigned short len;
 384   const unsigned short value;
 385   const bool always_warn_if_redefined;
 386 };
 387
 388 #define B(n, t, f)    { DSC(n), t, f }
 389 static const struct builtin_macro builtin_array[] =
 390 {
 391   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 392   B("__TIME__",          BT_TIME,          false),
 393   B("__DATE__",          BT_DATE,          false),
 394   B("__FILE__",          BT_FILE,          false),
 395   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 396   B("__LINE__",          BT_SPECLINE,      true),
 397   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 398   B("__COUNTER__",       BT_COUNTER,       true),
 399   B("__has_attribute",   BT_HAS_ATTRIBUTE, true),
 400   B("__has_cpp_attribute", BT_HAS_ATTRIBUTE, true),
 401   /* Keep builtins not used for -traditional-cpp at the end, and
 402      update init_builtins() if any more are added.  */
 403   B("_Pragma",           BT_PRAGMA,        true),
 404   B("__STDC__",          BT_STDC,          true),
 405 };
 406 #undef B
 407
 408 struct builtin_operator
 409 {
 410   const uchar *const name;
 411   const unsigned short len;
 412   const unsigned short value;
 413 };
 414
 415 #define B(n, t)    { DSC(n), t }
 416 static const struct builtin_operator operator_array[] =
 417 {
 418   B("and",      CPP_AND_AND),
 419   B("and_eq",   CPP_AND_EQ),
 420   B("bitand",   CPP_AND),
 421   B("bitor",    CPP_OR),
 422   B("compl",    CPP_COMPL),
 423   B("not",      CPP_NOT),
 424   B("not_eq",   CPP_NOT_EQ),
 425   B("or",       CPP_OR_OR),
 426   B("or_eq",    CPP_OR_EQ),
 427   B("xor",      CPP_XOR),
 428   B("xor_eq",   CPP_XOR_EQ)
 429 };
 430 #undef B
 431
 432 /* Mark the C++ named operators in the hash table.  */
 433 static void
 434 mark_named_operators (cpp_reader *pfile, int flags)
 435 {
 436   const struct builtin_operator *b;
 437
 438   for (b = operator_array;
 439        b < (operator_array + ARRAY_SIZE (operator_array));
 440        b++)
 441     {
 442       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 443       hp->flags |= flags;
 444       hp->is_directive = 0;
 445       hp->directive_index = b->value;
 446     }
 447 }
 448
 449 /* Helper function of cpp_type2name. Return the string associated with
 450    named operator TYPE.  */
 451 const char *
 452 cpp_named_operator2name (enum cpp_ttype type)
 453 {
 454   const struct builtin_operator *b;
 455
 456   for (b = operator_array;
 457        b < (operator_array + ARRAY_SIZE (operator_array));
 458        b++)
 459     {
 460       if (type == b->value)
 461         return (const char *) b->name;
 462     }
 463
 464   return NULL;
 465 }
 466
 467 void
 468 cpp_init_special_builtins (cpp_reader *pfile)
 469 {
 470   const struct builtin_macro *b;
 471   size_t n = ARRAY_SIZE (builtin_array);
 472
 473   if (CPP_OPTION (pfile, traditional))
 474     n -= 2;
 475   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 476            || CPP_OPTION (pfile, std))
 477     n--;
 478
 479   for (b = builtin_array; b < builtin_array + n; b++)
 480     {
 481       if (b->value == BT_HAS_ATTRIBUTE
 482           && (CPP_OPTION (pfile, lang) == CLK_ASM
 483               || pfile->cb.has_attribute == NULL))
 484         continue;
 485       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 486       hp->type = NT_BUILTIN_MACRO;
 487       if (b->always_warn_if_redefined)
 488         hp->flags |= NODE_WARN;
 489       hp->value.builtin = (enum cpp_builtin_type) b->value;
 490     }
 491 }
 492
 493 /* Read the builtins table above and enter them, and language-specific
 494    macros, into the hash table.  HOSTED is true if this is a hosted
 495    environment.  */
 496 void
 497 cpp_init_builtins (cpp_reader *pfile, int hosted)
 498 {
 499   cpp_init_special_builtins (pfile);
 500
 501   if (!CPP_OPTION (pfile, traditional)
 502       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 503           || CPP_OPTION (pfile, std)))
 504     _cpp_define_builtin (pfile, "__STDC__ 1");
 505
 506   if (CPP_OPTION (pfile, cplusplus))
 507     {
 508       if (CPP_OPTION (pfile, lang) == CLK_CXX2A
 509           || CPP_OPTION (pfile, lang) == CLK_GNUCXX2A)
 510         _cpp_define_builtin (pfile, "__cplusplus 201709L");
 511       else if (CPP_OPTION (pfile, lang) == CLK_CXX17
 512           || CPP_OPTION (pfile, lang) == CLK_GNUCXX17)
 513         _cpp_define_builtin (pfile, "__cplusplus 201703L");
 514       else if (CPP_OPTION (pfile, lang) == CLK_CXX14
 515           || CPP_OPTION (pfile, lang) == CLK_GNUCXX14)
 516         _cpp_define_builtin (pfile, "__cplusplus 201402L");
 517       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 518                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 519         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 520       else
 521         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 522     }
 523   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 524     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 525   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 526     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 527   else if (CPP_OPTION (pfile, lang) == CLK_STDC2X
 528            || CPP_OPTION (pfile, lang) == CLK_GNUC2X)
 529     _cpp_define_builtin (pfile, "__STDC_VERSION__ 202000L");
 530   else if (CPP_OPTION (pfile, lang) == CLK_STDC17
 531            || CPP_OPTION (pfile, lang) == CLK_GNUC17)
 532     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201710L");
 533   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 534            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 535     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 536   else if (CPP_OPTION (pfile, c99))
 537     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 538
 539   if (CPP_OPTION (pfile, uliterals)
 540       && !(CPP_OPTION (pfile, cplusplus)
 541            && (CPP_OPTION (pfile, lang) == CLK_GNUCXX
 542             || CPP_OPTION (pfile, lang) == CLK_CXX98)))
 543     {
 544       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 545       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 546     }
 547
 548   if (hosted)
 549     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 550   else
 551     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 552
 553   if (CPP_OPTION (pfile, objc))
 554     _cpp_define_builtin (pfile, "__OBJC__ 1");
 555 }
 556
 557 /* Sanity-checks are dependent on command-line options, so it is
 558    called as a subroutine of cpp_read_main_file.  */
 559 #if CHECKING_P
 560 static void sanity_checks (cpp_reader *);
 561 static void sanity_checks (cpp_reader *pfile)
 562 {
 563   cppchar_t test = 0;
 564   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 565
 566   /* Sanity checks for assumptions about CPP arithmetic and target
 567      type precisions made by cpplib.  */
 568   test--;
 569   if (test < 1)
 570     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 571
 572   if (CPP_OPTION (pfile, precision) > max_precision)
 573     cpp_error (pfile, CPP_DL_ICE,
 574                "preprocessor arithmetic has maximum precision of %lu bits;"
 575                " target requires %lu bits",
 576                (unsigned long) max_precision,
 577                (unsigned long) CPP_OPTION (pfile, precision));
 578
 579   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 580     cpp_error (pfile, CPP_DL_ICE,
 581                "CPP arithmetic must be at least as precise as a target int");
 582
 583   if (CPP_OPTION (pfile, char_precision) < 8)
 584     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 585
 586   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 587     cpp_error (pfile, CPP_DL_ICE,
 588                "target wchar_t is narrower than target char");
 589
 590   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 591     cpp_error (pfile, CPP_DL_ICE,
 592                "target int is narrower than target char");
 593
 594   /* This is assumed in eval_token() and could be fixed if necessary.  */
 595   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 596     cpp_error (pfile, CPP_DL_ICE,
 597                "CPP half-integer narrower than CPP character");
 598
 599   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 600     cpp_error (pfile, CPP_DL_ICE,
 601                "CPP on this host cannot handle wide character constants over"
 602                " %lu bits, but the target requires %lu bits",
 603                (unsigned long) BITS_PER_CPPCHAR_T,
 604                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 605 }
 606 #else
 607 # define sanity_checks(PFILE)
 608 #endif
 609
 610 /* This is called after options have been parsed, and partially
 611    processed.  */
 612 void
 613 cpp_post_options (cpp_reader *pfile)
 614 {
 615   int flags;
 616
 617   sanity_checks (pfile);
 618
 619   post_options (pfile);
 620
 621   /* Mark named operators before handling command line macros.  */
 622   flags = 0;
 623   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 624     flags |= NODE_OPERATOR;
 625   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 626     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 627   if (flags != 0)
 628     mark_named_operators (pfile, flags);
 629 }
 630
 631 /* Setup for processing input from the file named FNAME, or stdin if
 632    it is the empty string.  Return the original filename
 633    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 634 const char *
 635 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 636 {
 637   const location_t loc = 0;
 638
 639   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 640     {
 641       if (!pfile->deps)
 642         pfile->deps = deps_init ();
 643
 644       /* Set the default target (if there is none already).  */
 645       deps_add_default_target (pfile->deps, fname);
 646     }
 647
 648   pfile->main_file
 649     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false,
 650                       loc);
 651   if (_cpp_find_failed (pfile->main_file))
 652     return NULL;
 653
 654   _cpp_stack_file (pfile, pfile->main_file, IT_MAIN, 0);
 655
 656   /* For foo.i, read the original filename foo.c now, for the benefit
 657      of the front ends.  */
 658   if (CPP_OPTION (pfile, preprocessed))
 659     {
 660       read_original_filename (pfile);
 661       fname =
 662         ORDINARY_MAP_FILE_NAME
 663         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 664     }
 665   return fname;
 666 }
 667
 668 /* For preprocessed files, if the first tokens are of the form # NUM.
 669    handle the directive so we know the original file name.  This will
 670    generate file_change callbacks, which the front ends must handle
 671    appropriately given their state of initialization.  */
 672 static void
 673 read_original_filename (cpp_reader *pfile)
 674 {
 675   const cpp_token *token, *token1;
 676
 677   /* Lex ahead; if the first tokens are of the form # NUM, then
 678      process the directive, otherwise back up.  */
 679   token = _cpp_lex_direct (pfile);
 680   if (token->type == CPP_HASH)
 681     {
 682       pfile->state.in_directive = 1;
 683       token1 = _cpp_lex_direct (pfile);
 684       _cpp_backup_tokens (pfile, 1);
 685       pfile->state.in_directive = 0;
 686
 687       /* If it's a #line directive, handle it.  */
 688       if (token1->type == CPP_NUMBER
 689           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 690         {
 691           read_original_directory (pfile);
 692           return;
 693         }
 694     }
 695
 696   /* Backup as if nothing happened.  */
 697   _cpp_backup_tokens (pfile, 1);
 698 }
 699
 700 /* For preprocessed files, if the tokens following the first filename
 701    line is of the form # <line> "/path/name//", handle the
 702    directive so we know the original current directory.  */
 703 static void
 704 read_original_directory (cpp_reader *pfile)
 705 {
 706   const cpp_token *hash, *token;
 707
 708   /* Lex ahead; if the first tokens are of the form # NUM, then
 709      process the directive, otherwise back up.  */
 710   hash = _cpp_lex_direct (pfile);
 711   if (hash->type != CPP_HASH)
 712     {
 713       _cpp_backup_tokens (pfile, 1);
 714       return;
 715     }
 716
 717   token = _cpp_lex_direct (pfile);
 718
 719   if (token->type != CPP_NUMBER)
 720     {
 721       _cpp_backup_tokens (pfile, 2);
 722       return;
 723     }
 724
 725   token = _cpp_lex_direct (pfile);
 726
 727   if (token->type != CPP_STRING
 728       || ! (token->val.str.len >= 5
 729             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 730             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 731     {
 732       _cpp_backup_tokens (pfile, 3);
 733       return;
 734     }
 735
 736   if (pfile->cb.dir_change)
 737     {
 738       char *debugdir = (char *) alloca (token->val.str.len - 3);
 739
 740       memcpy (debugdir, (const char *) token->val.str.text + 1,
 741               token->val.str.len - 4);
 742       debugdir[token->val.str.len - 4] = '\0';
 743
 744       pfile->cb.dir_change (pfile, debugdir);
 745     }
 746 }
 747
 748 /* This is called at the end of preprocessing.  It pops the last
 749    buffer and writes dependency output.
 750
 751    Maybe it should also reset state, such that you could call
 752    cpp_start_read with a new filename to restart processing.  */
 753 void
 754 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 755 {
 756   /* Warn about unused macros before popping the final buffer.  */
 757   if (CPP_OPTION (pfile, warn_unused_macros))
 758     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 759
 760   /* lex.c leaves the final buffer on the stack.  This it so that
 761      it returns an unending stream of CPP_EOFs to the client.  If we
 762      popped the buffer, we'd dereference a NULL buffer pointer and
 763      segfault.  It's nice to allow the client to do worry-free excess
 764      cpp_get_token calls.  */
 765   while (pfile->buffer)
 766     _cpp_pop_buffer (pfile);
 767
 768   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE && deps_stream)
 769     deps_write (pfile->deps, deps_stream,
 770                 CPP_OPTION (pfile, deps.phony_targets), 72);
 771
 772   /* Report on headers that could use multiple include guards.  */
 773   if (CPP_OPTION (pfile, print_include_names))
 774     _cpp_report_missing_guards (pfile);
 775 }
 776
 777 static void
 778 post_options (cpp_reader *pfile)
 779 {
 780   /* -Wtraditional is not useful in C++ mode.  */
 781   if (CPP_OPTION (pfile, cplusplus))
 782     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 783
 784   /* Permanently disable macro expansion if we are rescanning
 785      preprocessed text.  Read preprocesed source in ISO mode.  */
 786   if (CPP_OPTION (pfile, preprocessed))
 787     {
 788       if (!CPP_OPTION (pfile, directives_only))
 789         pfile->state.prevent_expansion = 1;
 790       CPP_OPTION (pfile, traditional) = 0;
 791     }
 792
 793   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 794     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 795
 796   if (CPP_OPTION (pfile, traditional))
 797     {
 798       CPP_OPTION (pfile, trigraphs) = 0;
 799       CPP_OPTION (pfile, warn_trigraphs) = 0;
 800     }
 801 }