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