libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2018 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                    struct 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, tabstop) = 8;
 189   CPP_OPTION (pfile, operator_names) = 1;
 190   CPP_OPTION (pfile, warn_trigraphs) = 2;
 191   CPP_OPTION (pfile, warn_endif_labels) = 1;
 192   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
 193   CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0;
 194   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 195   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 196   CPP_OPTION (pfile, dollars_in_ident) = 1;
 197   CPP_OPTION (pfile, warn_dollars) = 1;
 198   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 199   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 200   CPP_OPTION (pfile, cpp_warn_implicit_fallthrough) = 0;
 201   /* By default, track locations of tokens resulting from macro
 202      expansion.  The '2' means, track the locations with the highest
 203      accuracy.  Read the comments for struct
 204      cpp_options::track_macro_expansion to learn about the other
 205      values.  */
 206   CPP_OPTION (pfile, track_macro_expansion) = 2;
 207   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 208   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 209   CPP_OPTION (pfile, canonical_system_headers)
 210       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 211   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 212   CPP_OPTION (pfile, warn_date_time) = 0;
 213
 214   /* Default CPP arithmetic to something sensible for the host for the
 215      benefit of dumb users like fix-header.  */
 216   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 217   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 218   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 219   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 220   CPP_OPTION (pfile, unsigned_char) = 0;
 221   CPP_OPTION (pfile, unsigned_wchar) = 1;
 222   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 223
 224   /* Default to no charset conversion.  */
 225   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 226   CPP_OPTION (pfile, wide_charset) = 0;
 227
 228   /* Default the input character set to UTF-8.  */
 229   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 230
 231   /* A fake empty "directory" used as the starting point for files
 232      looked up without a search path.  Name cannot be '/' because we
 233      don't want to prepend anything at all to filenames using it.  All
 234      other entries are correct zero-initialized.  */
 235   pfile->no_search_path.name = (char *) "";
 236
 237   /* Initialize the line map.  */
 238   pfile->line_table = line_table;
 239
 240   /* Initialize lexer state.  */
 241   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 242
 243   /* Set up static tokens.  */
 244   pfile->avoid_paste.type = CPP_PADDING;
 245   pfile->avoid_paste.val.source = NULL;
 246   pfile->eof.type = CPP_EOF;
 247   pfile->eof.flags = 0;
 248
 249   /* Create a token buffer for the lexer.  */
 250   _cpp_init_tokenrun (&pfile->base_run, 250);
 251   pfile->cur_run = &pfile->base_run;
 252   pfile->cur_token = pfile->base_run.base;
 253
 254   /* Initialize the base context.  */
 255   pfile->context = &pfile->base_context;
 256   pfile->base_context.c.macro = 0;
 257   pfile->base_context.prev = pfile->base_context.next = 0;
 258
 259   /* Aligned and unaligned storage.  */
 260   pfile->a_buff = _cpp_get_buff (pfile, 0);
 261   pfile->u_buff = _cpp_get_buff (pfile, 0);
 262
 263   /* Initialize table for push_macro/pop_macro.  */
 264   pfile->pushed_macros = 0;
 265
 266   /* Do not force token locations by default.  */
 267   pfile->forced_token_location = 0;
 268
 269   /* Initialize source_date_epoch to -2 (not yet set).  */
 270   pfile->source_date_epoch = (time_t) -2;
 271
 272   /* The expression parser stack.  */
 273   _cpp_expand_op_stack (pfile);
 274
 275   /* Initialize the buffer obstack.  */
 276   obstack_specify_allocation (&pfile->buffer_ob, 0, 0, xmalloc, free);
 277
 278   _cpp_init_files (pfile);
 279
 280   _cpp_init_hashtable (pfile, table);
 281
 282   return pfile;
 283 }
 284
 285 /* Set the line_table entry in PFILE.  This is called after reading a
 286    PCH file, as the old line_table will be incorrect.  */
 287 void
 288 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 289 {
 290   pfile->line_table = line_table;
 291 }
 292
 293 /* Free resources used by PFILE.  Accessing PFILE after this function
 294    returns leads to undefined behavior.  Returns the error count.  */
 295 void
 296 cpp_destroy (cpp_reader *pfile)
 297 {
 298   cpp_context *context, *contextn;
 299   struct def_pragma_macro *pmacro;
 300   tokenrun *run, *runn;
 301   int i;
 302
 303   free (pfile->op_stack);
 304
 305   while (CPP_BUFFER (pfile) != NULL)
 306     _cpp_pop_buffer (pfile);
 307
 308   free (pfile->out.base);
 309
 310   if (pfile->macro_buffer)
 311     {
 312       free (pfile->macro_buffer);
 313       pfile->macro_buffer = NULL;
 314       pfile->macro_buffer_len = 0;
 315     }
 316
 317   if (pfile->deps)
 318     deps_free (pfile->deps);
 319   obstack_free (&pfile->buffer_ob, 0);
 320
 321   _cpp_destroy_hashtable (pfile);
 322   _cpp_cleanup_files (pfile);
 323   _cpp_destroy_iconv (pfile);
 324
 325   _cpp_free_buff (pfile->a_buff);
 326   _cpp_free_buff (pfile->u_buff);
 327   _cpp_free_buff (pfile->free_buffs);
 328
 329   for (run = &pfile->base_run; run; run = runn)
 330     {
 331       runn = run->next;
 332       free (run->base);
 333       if (run != &pfile->base_run)
 334         free (run);
 335     }
 336
 337   for (context = pfile->base_context.next; context; context = contextn)
 338     {
 339       contextn = context->next;
 340       free (context);
 341     }
 342
 343   if (pfile->comments.entries)
 344     {
 345       for (i = 0; i < pfile->comments.count; i++)
 346         free (pfile->comments.entries[i].comment);
 347
 348       free (pfile->comments.entries);
 349     }
 350   if (pfile->pushed_macros)
 351     {
 352       do
 353         {
 354           pmacro = pfile->pushed_macros;
 355           pfile->pushed_macros = pmacro->next;
 356           free (pmacro->name);
 357           free (pmacro);
 358         }
 359       while (pfile->pushed_macros);
 360     }
 361
 362   free (pfile);
 363 }
 364
 365 /* This structure defines one built-in identifier.  A node will be
 366    entered in the hash table under the name NAME, with value VALUE.
 367
 368    There are two tables of these.  builtin_array holds all the
 369    "builtin" macros: these are handled by builtin_macro() in
 370    macro.c.  Builtin is somewhat of a misnomer -- the property of
 371    interest is that these macros require special code to compute their
 372    expansions.  The value is a "cpp_builtin_type" enumerator.
 373
 374    operator_array holds the C++ named operators.  These are keywords
 375    which act as aliases for punctuators.  In C++, they cannot be
 376    altered through #define, and #if recognizes them as operators.  In
 377    C, these are not entered into the hash table at all (but see
 378    <iso646.h>).  The value is a token-type enumerator.  */
 379 struct builtin_macro
 380 {
 381   const uchar *const name;
 382   const unsigned short len;
 383   const unsigned short value;
 384   const bool always_warn_if_redefined;
 385 };
 386
 387 #define B(n, t, f)    { DSC(n), t, f }
 388 static const struct builtin_macro builtin_array[] =
 389 {
 390   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 391   B("__TIME__",          BT_TIME,          false),
 392   B("__DATE__",          BT_DATE,          false),
 393   B("__FILE__",          BT_FILE,          false),
 394   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 395   B("__LINE__",          BT_SPECLINE,      true),
 396   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 397   B("__COUNTER__",       BT_COUNTER,       true),
 398   B("__has_attribute",   BT_HAS_ATTRIBUTE, true),
 399   B("__has_cpp_attribute", BT_HAS_ATTRIBUTE, true),
 400   /* Keep builtins not used for -traditional-cpp at the end, and
 401      update init_builtins() if any more are added.  */
 402   B("_Pragma",           BT_PRAGMA,        true),
 403   B("__STDC__",          BT_STDC,          true),
 404 };
 405 #undef B
 406
 407 struct builtin_operator
 408 {
 409   const uchar *const name;
 410   const unsigned short len;
 411   const unsigned short value;
 412 };
 413
 414 #define B(n, t)    { DSC(n), t }
 415 static const struct builtin_operator operator_array[] =
 416 {
 417   B("and",      CPP_AND_AND),
 418   B("and_eq",   CPP_AND_EQ),
 419   B("bitand",   CPP_AND),
 420   B("bitor",    CPP_OR),
 421   B("compl",    CPP_COMPL),
 422   B("not",      CPP_NOT),
 423   B("not_eq",   CPP_NOT_EQ),
 424   B("or",       CPP_OR_OR),
 425   B("or_eq",    CPP_OR_EQ),
 426   B("xor",      CPP_XOR),
 427   B("xor_eq",   CPP_XOR_EQ)
 428 };
 429 #undef B
 430
 431 /* Mark the C++ named operators in the hash table.  */
 432 static void
 433 mark_named_operators (cpp_reader *pfile, int flags)
 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       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 442       hp->flags |= flags;
 443       hp->is_directive = 0;
 444       hp->directive_index = b->value;
 445     }
 446 }
 447
 448 /* Helper function of cpp_type2name. Return the string associated with
 449    named operator TYPE.  */
 450 const char *
 451 cpp_named_operator2name (enum cpp_ttype type)
 452 {
 453   const struct builtin_operator *b;
 454
 455   for (b = operator_array;
 456        b < (operator_array + ARRAY_SIZE (operator_array));
 457        b++)
 458     {
 459       if (type == b->value)
 460         return (const char *) b->name;
 461     }
 462
 463   return NULL;
 464 }
 465
 466 void
 467 cpp_init_special_builtins (cpp_reader *pfile)
 468 {
 469   const struct builtin_macro *b;
 470   size_t n = ARRAY_SIZE (builtin_array);
 471
 472   if (CPP_OPTION (pfile, traditional))
 473     n -= 2;
 474   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 475            || CPP_OPTION (pfile, std))
 476     n--;
 477
 478   for (b = builtin_array; b < builtin_array + n; b++)
 479     {
 480       if (b->value == BT_HAS_ATTRIBUTE
 481           && (CPP_OPTION (pfile, lang) == CLK_ASM
 482               || pfile->cb.has_attribute == NULL))
 483         continue;
 484       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 485       hp->type = NT_BUILTIN_MACRO;
 486       if (b->always_warn_if_redefined)
 487         hp->flags |= NODE_WARN;
 488       hp->value.builtin = (enum cpp_builtin_type) b->value;
 489     }
 490 }
 491
 492 /* Read the builtins table above and enter them, and language-specific
 493    macros, into the hash table.  HOSTED is true if this is a hosted
 494    environment.  */
 495 void
 496 cpp_init_builtins (cpp_reader *pfile, int hosted)
 497 {
 498   cpp_init_special_builtins (pfile);
 499
 500   if (!CPP_OPTION (pfile, traditional)
 501       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 502           || CPP_OPTION (pfile, std)))
 503     _cpp_define_builtin (pfile, "__STDC__ 1");
 504
 505   if (CPP_OPTION (pfile, cplusplus))
 506     {
 507       if (CPP_OPTION (pfile, lang) == CLK_CXX2A
 508           || CPP_OPTION (pfile, lang) == CLK_GNUCXX2A)
 509         _cpp_define_builtin (pfile, "__cplusplus 201709L");
 510       else if (CPP_OPTION (pfile, lang) == CLK_CXX17
 511           || CPP_OPTION (pfile, lang) == CLK_GNUCXX17)
 512         _cpp_define_builtin (pfile, "__cplusplus 201703L");
 513       else if (CPP_OPTION (pfile, lang) == CLK_CXX14
 514           || CPP_OPTION (pfile, lang) == CLK_GNUCXX14)
 515         _cpp_define_builtin (pfile, "__cplusplus 201402L");
 516       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 517                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 518         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 519       else
 520         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 521     }
 522   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 523     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 524   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 525     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 526   else if (CPP_OPTION (pfile, lang) == CLK_STDC2X
 527            || CPP_OPTION (pfile, lang) == CLK_GNUC2X)
 528     _cpp_define_builtin (pfile, "__STDC_VERSION__ 202000L");
 529   else if (CPP_OPTION (pfile, lang) == CLK_STDC17
 530            || CPP_OPTION (pfile, lang) == CLK_GNUC17)
 531     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201710L");
 532   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 533            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 534     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 535   else if (CPP_OPTION (pfile, c99))
 536     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 537
 538   if (CPP_OPTION (pfile, uliterals)
 539       && !(CPP_OPTION (pfile, cplusplus)
 540            && (CPP_OPTION (pfile, lang) == CLK_GNUCXX
 541             || CPP_OPTION (pfile, lang) == CLK_CXX98)))
 542     {
 543       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 544       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 545     }
 546
 547   if (hosted)
 548     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 549   else
 550     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 551
 552   if (CPP_OPTION (pfile, objc))
 553     _cpp_define_builtin (pfile, "__OBJC__ 1");
 554 }
 555
 556 /* Sanity-checks are dependent on command-line options, so it is
 557    called as a subroutine of cpp_read_main_file.  */
 558 #if CHECKING_P
 559 static void sanity_checks (cpp_reader *);
 560 static void sanity_checks (cpp_reader *pfile)
 561 {
 562   cppchar_t test = 0;
 563   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 564
 565   /* Sanity checks for assumptions about CPP arithmetic and target
 566      type precisions made by cpplib.  */
 567   test--;
 568   if (test < 1)
 569     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 570
 571   if (CPP_OPTION (pfile, precision) > max_precision)
 572     cpp_error (pfile, CPP_DL_ICE,
 573                "preprocessor arithmetic has maximum precision of %lu bits;"
 574                " target requires %lu bits",
 575                (unsigned long) max_precision,
 576                (unsigned long) CPP_OPTION (pfile, precision));
 577
 578   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 579     cpp_error (pfile, CPP_DL_ICE,
 580                "CPP arithmetic must be at least as precise as a target int");
 581
 582   if (CPP_OPTION (pfile, char_precision) < 8)
 583     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 584
 585   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 586     cpp_error (pfile, CPP_DL_ICE,
 587                "target wchar_t is narrower than target char");
 588
 589   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 590     cpp_error (pfile, CPP_DL_ICE,
 591                "target int is narrower than target char");
 592
 593   /* This is assumed in eval_token() and could be fixed if necessary.  */
 594   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 595     cpp_error (pfile, CPP_DL_ICE,
 596                "CPP half-integer narrower than CPP character");
 597
 598   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 599     cpp_error (pfile, CPP_DL_ICE,
 600                "CPP on this host cannot handle wide character constants over"
 601                " %lu bits, but the target requires %lu bits",
 602                (unsigned long) BITS_PER_CPPCHAR_T,
 603                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 604 }
 605 #else
 606 # define sanity_checks(PFILE)
 607 #endif
 608
 609 /* This is called after options have been parsed, and partially
 610    processed.  */
 611 void
 612 cpp_post_options (cpp_reader *pfile)
 613 {
 614   int flags;
 615
 616   sanity_checks (pfile);
 617
 618   post_options (pfile);
 619
 620   /* Mark named operators before handling command line macros.  */
 621   flags = 0;
 622   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 623     flags |= NODE_OPERATOR;
 624   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 625     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 626   if (flags != 0)
 627     mark_named_operators (pfile, flags);
 628 }
 629
 630 /* Setup for processing input from the file named FNAME, or stdin if
 631    it is the empty string.  Return the original filename
 632    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 633 const char *
 634 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 635 {
 636   const location_t loc = 0;
 637
 638   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 639     {
 640       if (!pfile->deps)
 641         pfile->deps = deps_init ();
 642
 643       /* Set the default target (if there is none already).  */
 644       deps_add_default_target (pfile->deps, fname);
 645     }
 646
 647   pfile->main_file
 648     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false,
 649                       loc);
 650   if (_cpp_find_failed (pfile->main_file))
 651     return NULL;
 652
 653   _cpp_stack_file (pfile, pfile->main_file, false, loc);
 654
 655   /* For foo.i, read the original filename foo.c now, for the benefit
 656      of the front ends.  */
 657   if (CPP_OPTION (pfile, preprocessed))
 658     {
 659       read_original_filename (pfile);
 660       fname =
 661         ORDINARY_MAP_FILE_NAME
 662         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 663     }
 664   return fname;
 665 }
 666
 667 /* For preprocessed files, if the first tokens are of the form # NUM.
 668    handle the directive so we know the original file name.  This will
 669    generate file_change callbacks, which the front ends must handle
 670    appropriately given their state of initialization.  */
 671 static void
 672 read_original_filename (cpp_reader *pfile)
 673 {
 674   const cpp_token *token, *token1;
 675
 676   /* Lex ahead; if the first tokens are of the form # NUM, then
 677      process the directive, otherwise back up.  */
 678   token = _cpp_lex_direct (pfile);
 679   if (token->type == CPP_HASH)
 680     {
 681       pfile->state.in_directive = 1;
 682       token1 = _cpp_lex_direct (pfile);
 683       _cpp_backup_tokens (pfile, 1);
 684       pfile->state.in_directive = 0;
 685
 686       /* If it's a #line directive, handle it.  */
 687       if (token1->type == CPP_NUMBER
 688           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 689         {
 690           read_original_directory (pfile);
 691           return;
 692         }
 693     }
 694
 695   /* Backup as if nothing happened.  */
 696   _cpp_backup_tokens (pfile, 1);
 697 }
 698
 699 /* For preprocessed files, if the tokens following the first filename
 700    line is of the form # <line> "/path/name//", handle the
 701    directive so we know the original current directory.  */
 702 static void
 703 read_original_directory (cpp_reader *pfile)
 704 {
 705   const cpp_token *hash, *token;
 706
 707   /* Lex ahead; if the first tokens are of the form # NUM, then
 708      process the directive, otherwise back up.  */
 709   hash = _cpp_lex_direct (pfile);
 710   if (hash->type != CPP_HASH)
 711     {
 712       _cpp_backup_tokens (pfile, 1);
 713       return;
 714     }
 715
 716   token = _cpp_lex_direct (pfile);
 717
 718   if (token->type != CPP_NUMBER)
 719     {
 720       _cpp_backup_tokens (pfile, 2);
 721       return;
 722     }
 723
 724   token = _cpp_lex_direct (pfile);
 725
 726   if (token->type != CPP_STRING
 727       || ! (token->val.str.len >= 5
 728             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 729             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 730     {
 731       _cpp_backup_tokens (pfile, 3);
 732       return;
 733     }
 734
 735   if (pfile->cb.dir_change)
 736     {
 737       char *debugdir = (char *) alloca (token->val.str.len - 3);
 738
 739       memcpy (debugdir, (const char *) token->val.str.text + 1,
 740               token->val.str.len - 4);
 741       debugdir[token->val.str.len - 4] = '\0';
 742
 743       pfile->cb.dir_change (pfile, debugdir);
 744     }
 745 }
 746
 747 /* This is called at the end of preprocessing.  It pops the last
 748    buffer and writes dependency output.
 749
 750    Maybe it should also reset state, such that you could call
 751    cpp_start_read with a new filename to restart processing.  */
 752 void
 753 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 754 {
 755   /* Warn about unused macros before popping the final buffer.  */
 756   if (CPP_OPTION (pfile, warn_unused_macros))
 757     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 758
 759   /* lex.c leaves the final buffer on the stack.  This it so that
 760      it returns an unending stream of CPP_EOFs to the client.  If we
 761      popped the buffer, we'd dereference a NULL buffer pointer and
 762      segfault.  It's nice to allow the client to do worry-free excess
 763      cpp_get_token calls.  */
 764   while (pfile->buffer)
 765     _cpp_pop_buffer (pfile);
 766
 767   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 768       && deps_stream)
 769     {
 770       deps_write (pfile->deps, deps_stream, 72);
 771
 772       if (CPP_OPTION (pfile, deps.phony_targets))
 773         deps_phony_targets (pfile->deps, deps_stream);
 774     }
 775
 776   /* Report on headers that could use multiple include guards.  */
 777   if (CPP_OPTION (pfile, print_include_names))
 778     _cpp_report_missing_guards (pfile);
 779 }
 780
 781 static void
 782 post_options (cpp_reader *pfile)
 783 {
 784   /* -Wtraditional is not useful in C++ mode.  */
 785   if (CPP_OPTION (pfile, cplusplus))
 786     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 787
 788   /* Permanently disable macro expansion if we are rescanning
 789      preprocessed text.  Read preprocesed source in ISO mode.  */
 790   if (CPP_OPTION (pfile, preprocessed))
 791     {
 792       if (!CPP_OPTION (pfile, directives_only))
 793         pfile->state.prevent_expansion = 1;
 794       CPP_OPTION (pfile, traditional) = 0;
 795     }
 796
 797   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 798     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 799
 800   if (CPP_OPTION (pfile, traditional))
 801     {
 802       CPP_OPTION (pfile, trigraphs) = 0;
 803       CPP_OPTION (pfile, warn_trigraphs) = 0;
 804     }
 805 }