libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2017 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 };
  95
  96 static const struct lang_flags lang_defaults[] =
  97 { /*              c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit */
  98   /* GNUC89   */  { 0,  0,  1,  0,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0 },
  99   /* GNUC99   */  { 1,  0,  1,  1,  0,  0,  1,   1,   1,   0,    0,     0,     0,   0 },
 100   /* GNUC11   */  { 1,  0,  1,  1,  1,  0,  1,   1,   1,   0,    0,     0,     0,   0 },
 101   /* STDC89   */  { 0,  0,  0,  0,  0,  1,  0,   0,   0,   0,    0,     0,     1,   0 },
 102   /* STDC94   */  { 0,  0,  0,  0,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0 },
 103   /* STDC99   */  { 1,  0,  1,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0 },
 104   /* STDC11   */  { 1,  0,  1,  1,  1,  1,  1,   1,   0,   0,    0,     0,     1,   0 },
 105   /* GNUCXX   */  { 0,  1,  1,  1,  0,  0,  1,   0,   0,   0,    0,     0,     0,   0 },
 106   /* CXX98    */  { 0,  1,  0,  1,  0,  1,  1,   0,   0,   0,    0,     0,     1,   0 },
 107   /* GNUCXX11 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    0,     0,     0,   0 },
 108   /* CXX11    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    0,     0,     1,   0 },
 109   /* GNUCXX14 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   0 },
 110   /* CXX14    */  { 1,  1,  0,  1,  1,  1,  1,   1,   1,   1,    1,     1,     1,   0 },
 111   /* GNUCXX17 */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1 },
 112   /* CXX17    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1 },
 113   /* GNUCXX2A */  { 1,  1,  1,  1,  1,  0,  1,   1,   1,   1,    1,     1,     0,   1 },
 114   /* CXX2A    */  { 1,  1,  1,  1,  1,  1,  1,   1,   1,   1,    1,     1,     0,   1 },
 115   /* ASM      */  { 0,  0,  1,  0,  0,  0,  0,   0,   0,   0,    0,     0,     0,   0 }
 116 };
 117
 118 /* Sets internal flags correctly for a given language.  */
 119 void
 120 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 121 {
 122   const struct lang_flags *l = &lang_defaults[(int) lang];
 123
 124   CPP_OPTION (pfile, lang) = lang;
 125
 126   CPP_OPTION (pfile, c99)                        = l->c99;
 127   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 128   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 129   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 130   CPP_OPTION (pfile, c11_identifiers)            = l->c11_identifiers;
 131   CPP_OPTION (pfile, std)                        = l->std;
 132   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 133   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 134   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 135   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 136   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 137   CPP_OPTION (pfile, digit_separators)           = l->digit_separators;
 138   CPP_OPTION (pfile, trigraphs)                  = l->trigraphs;
 139   CPP_OPTION (pfile, utf8_char_literals)         = l->utf8_char_literals;
 140 }
 141
 142 /* Initialize library global state.  */
 143 static void
 144 init_library (void)
 145 {
 146   static int initialized = 0;
 147
 148   if (! initialized)
 149     {
 150       initialized = 1;
 151
 152       _cpp_init_lexer ();
 153
 154       /* Set up the trigraph map.  This doesn't need to do anything if
 155          we were compiled with a compiler that supports C99 designated
 156          initializers.  */
 157       init_trigraph_map ();
 158
 159 #ifdef ENABLE_NLS
 160        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 161 #endif
 162     }
 163 }
 164
 165 /* Initialize a cpp_reader structure.  */
 166 cpp_reader *
 167 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 168                    struct line_maps *line_table)
 169 {
 170   cpp_reader *pfile;
 171
 172   /* Initialize this instance of the library if it hasn't been already.  */
 173   init_library ();
 174
 175   pfile = XCNEW (cpp_reader);
 176   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 177
 178   cpp_set_lang (pfile, lang);
 179   CPP_OPTION (pfile, warn_multichar) = 1;
 180   CPP_OPTION (pfile, discard_comments) = 1;
 181   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 182   CPP_OPTION (pfile, tabstop) = 8;
 183   CPP_OPTION (pfile, operator_names) = 1;
 184   CPP_OPTION (pfile, warn_trigraphs) = 2;
 185   CPP_OPTION (pfile, warn_endif_labels) = 1;
 186   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
 187   CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0;
 188   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 189   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 190   CPP_OPTION (pfile, dollars_in_ident) = 1;
 191   CPP_OPTION (pfile, warn_dollars) = 1;
 192   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 193   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 194   CPP_OPTION (pfile, cpp_warn_implicit_fallthrough) = 0;
 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   /* Initialize source_date_epoch to -2 (not yet set).  */
 264   pfile->source_date_epoch = (time_t) -2;
 265
 266   /* The expression parser stack.  */
 267   _cpp_expand_op_stack (pfile);
 268
 269   /* Initialize the buffer obstack.  */
 270   obstack_specify_allocation (&pfile->buffer_ob, 0, 0, xmalloc, free);
 271
 272   _cpp_init_files (pfile);
 273
 274   _cpp_init_hashtable (pfile, table);
 275
 276   return pfile;
 277 }
 278
 279 /* Set the line_table entry in PFILE.  This is called after reading a
 280    PCH file, as the old line_table will be incorrect.  */
 281 void
 282 cpp_set_line_map (cpp_reader *pfile, struct line_maps *line_table)
 283 {
 284   pfile->line_table = line_table;
 285 }
 286
 287 /* Free resources used by PFILE.  Accessing PFILE after this function
 288    returns leads to undefined behavior.  Returns the error count.  */
 289 void
 290 cpp_destroy (cpp_reader *pfile)
 291 {
 292   cpp_context *context, *contextn;
 293   struct def_pragma_macro *pmacro;
 294   tokenrun *run, *runn;
 295   int i;
 296
 297   free (pfile->op_stack);
 298
 299   while (CPP_BUFFER (pfile) != NULL)
 300     _cpp_pop_buffer (pfile);
 301
 302   free (pfile->out.base);
 303
 304   if (pfile->macro_buffer)
 305     {
 306       free (pfile->macro_buffer);
 307       pfile->macro_buffer = NULL;
 308       pfile->macro_buffer_len = 0;
 309     }
 310
 311   if (pfile->deps)
 312     deps_free (pfile->deps);
 313   obstack_free (&pfile->buffer_ob, 0);
 314
 315   _cpp_destroy_hashtable (pfile);
 316   _cpp_cleanup_files (pfile);
 317   _cpp_destroy_iconv (pfile);
 318
 319   _cpp_free_buff (pfile->a_buff);
 320   _cpp_free_buff (pfile->u_buff);
 321   _cpp_free_buff (pfile->free_buffs);
 322
 323   for (run = &pfile->base_run; run; run = runn)
 324     {
 325       runn = run->next;
 326       free (run->base);
 327       if (run != &pfile->base_run)
 328         free (run);
 329     }
 330
 331   for (context = pfile->base_context.next; context; context = contextn)
 332     {
 333       contextn = context->next;
 334       free (context);
 335     }
 336
 337   if (pfile->comments.entries)
 338     {
 339       for (i = 0; i < pfile->comments.count; i++)
 340         free (pfile->comments.entries[i].comment);
 341
 342       free (pfile->comments.entries);
 343     }
 344   if (pfile->pushed_macros)
 345     {
 346       do
 347         {
 348           pmacro = pfile->pushed_macros;
 349           pfile->pushed_macros = pmacro->next;
 350           free (pmacro->name);
 351           free (pmacro);
 352         }
 353       while (pfile->pushed_macros);
 354     }
 355
 356   free (pfile);
 357 }
 358
 359 /* This structure defines one built-in identifier.  A node will be
 360    entered in the hash table under the name NAME, with value VALUE.
 361
 362    There are two tables of these.  builtin_array holds all the
 363    "builtin" macros: these are handled by builtin_macro() in
 364    macro.c.  Builtin is somewhat of a misnomer -- the property of
 365    interest is that these macros require special code to compute their
 366    expansions.  The value is a "cpp_builtin_type" enumerator.
 367
 368    operator_array holds the C++ named operators.  These are keywords
 369    which act as aliases for punctuators.  In C++, they cannot be
 370    altered through #define, and #if recognizes them as operators.  In
 371    C, these are not entered into the hash table at all (but see
 372    <iso646.h>).  The value is a token-type enumerator.  */
 373 struct builtin_macro
 374 {
 375   const uchar *const name;
 376   const unsigned short len;
 377   const unsigned short value;
 378   const bool always_warn_if_redefined;
 379 };
 380
 381 #define B(n, t, f)    { DSC(n), t, f }
 382 static const struct builtin_macro builtin_array[] =
 383 {
 384   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 385   B("__TIME__",          BT_TIME,          false),
 386   B("__DATE__",          BT_DATE,          false),
 387   B("__FILE__",          BT_FILE,          false),
 388   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 389   B("__LINE__",          BT_SPECLINE,      true),
 390   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 391   B("__COUNTER__",       BT_COUNTER,       true),
 392   B("__has_attribute",   BT_HAS_ATTRIBUTE, true),
 393   B("__has_cpp_attribute", BT_HAS_ATTRIBUTE, true),
 394   /* Keep builtins not used for -traditional-cpp at the end, and
 395      update init_builtins() if any more are added.  */
 396   B("_Pragma",           BT_PRAGMA,        true),
 397   B("__STDC__",          BT_STDC,          true),
 398 };
 399 #undef B
 400
 401 struct builtin_operator
 402 {
 403   const uchar *const name;
 404   const unsigned short len;
 405   const unsigned short value;
 406 };
 407
 408 #define B(n, t)    { DSC(n), t }
 409 static const struct builtin_operator operator_array[] =
 410 {
 411   B("and",      CPP_AND_AND),
 412   B("and_eq",   CPP_AND_EQ),
 413   B("bitand",   CPP_AND),
 414   B("bitor",    CPP_OR),
 415   B("compl",    CPP_COMPL),
 416   B("not",      CPP_NOT),
 417   B("not_eq",   CPP_NOT_EQ),
 418   B("or",       CPP_OR_OR),
 419   B("or_eq",    CPP_OR_EQ),
 420   B("xor",      CPP_XOR),
 421   B("xor_eq",   CPP_XOR_EQ)
 422 };
 423 #undef B
 424
 425 /* Mark the C++ named operators in the hash table.  */
 426 static void
 427 mark_named_operators (cpp_reader *pfile, int flags)
 428 {
 429   const struct builtin_operator *b;
 430
 431   for (b = operator_array;
 432        b < (operator_array + ARRAY_SIZE (operator_array));
 433        b++)
 434     {
 435       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 436       hp->flags |= flags;
 437       hp->is_directive = 0;
 438       hp->directive_index = b->value;
 439     }
 440 }
 441
 442 /* Helper function of cpp_type2name. Return the string associated with
 443    named operator TYPE.  */
 444 const char *
 445 cpp_named_operator2name (enum cpp_ttype type)
 446 {
 447   const struct builtin_operator *b;
 448
 449   for (b = operator_array;
 450        b < (operator_array + ARRAY_SIZE (operator_array));
 451        b++)
 452     {
 453       if (type == b->value)
 454         return (const char *) b->name;
 455     }
 456
 457   return NULL;
 458 }
 459
 460 void
 461 cpp_init_special_builtins (cpp_reader *pfile)
 462 {
 463   const struct builtin_macro *b;
 464   size_t n = ARRAY_SIZE (builtin_array);
 465
 466   if (CPP_OPTION (pfile, traditional))
 467     n -= 2;
 468   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 469            || CPP_OPTION (pfile, std))
 470     n--;
 471
 472   for (b = builtin_array; b < builtin_array + n; b++)
 473     {
 474       if (b->value == BT_HAS_ATTRIBUTE
 475           && (CPP_OPTION (pfile, lang) == CLK_ASM
 476               || pfile->cb.has_attribute == NULL))
 477         continue;
 478       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 479       hp->type = NT_MACRO;
 480       hp->flags |= NODE_BUILTIN;
 481       if (b->always_warn_if_redefined)
 482         hp->flags |= NODE_WARN;
 483       hp->value.builtin = (enum cpp_builtin_type) b->value;
 484     }
 485 }
 486
 487 /* Read the builtins table above and enter them, and language-specific
 488    macros, into the hash table.  HOSTED is true if this is a hosted
 489    environment.  */
 490 void
 491 cpp_init_builtins (cpp_reader *pfile, int hosted)
 492 {
 493   cpp_init_special_builtins (pfile);
 494
 495   if (!CPP_OPTION (pfile, traditional)
 496       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 497           || CPP_OPTION (pfile, std)))
 498     _cpp_define_builtin (pfile, "__STDC__ 1");
 499
 500   if (CPP_OPTION (pfile, cplusplus))
 501     {
 502       if (CPP_OPTION (pfile, lang) == CLK_CXX2A
 503           || CPP_OPTION (pfile, lang) == CLK_GNUCXX2A)
 504         _cpp_define_builtin (pfile, "__cplusplus 201709L");
 505       else if (CPP_OPTION (pfile, lang) == CLK_CXX17
 506           || CPP_OPTION (pfile, lang) == CLK_GNUCXX17)
 507         _cpp_define_builtin (pfile, "__cplusplus 201703L");
 508       else if (CPP_OPTION (pfile, lang) == CLK_CXX14
 509           || CPP_OPTION (pfile, lang) == CLK_GNUCXX14)
 510         _cpp_define_builtin (pfile, "__cplusplus 201402L");
 511       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 512                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 513         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 514       else
 515         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 516     }
 517   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 518     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 519   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 520     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 521   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 522            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 523     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 524   else if (CPP_OPTION (pfile, c99))
 525     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 526
 527   if (CPP_OPTION (pfile, uliterals)
 528       && !(CPP_OPTION (pfile, cplusplus)
 529            && (CPP_OPTION (pfile, lang) == CLK_GNUCXX
 530             || CPP_OPTION (pfile, lang) == CLK_CXX98)))
 531     {
 532       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 533       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 534     }
 535
 536   if (hosted)
 537     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 538   else
 539     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 540
 541   if (CPP_OPTION (pfile, objc))
 542     _cpp_define_builtin (pfile, "__OBJC__ 1");
 543 }
 544
 545 /* Sanity-checks are dependent on command-line options, so it is
 546    called as a subroutine of cpp_read_main_file.  */
 547 #if CHECKING_P
 548 static void sanity_checks (cpp_reader *);
 549 static void sanity_checks (cpp_reader *pfile)
 550 {
 551   cppchar_t test = 0;
 552   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 553
 554   /* Sanity checks for assumptions about CPP arithmetic and target
 555      type precisions made by cpplib.  */
 556   test--;
 557   if (test < 1)
 558     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 559
 560   if (CPP_OPTION (pfile, precision) > max_precision)
 561     cpp_error (pfile, CPP_DL_ICE,
 562                "preprocessor arithmetic has maximum precision of %lu bits;"
 563                " target requires %lu bits",
 564                (unsigned long) max_precision,
 565                (unsigned long) CPP_OPTION (pfile, precision));
 566
 567   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 568     cpp_error (pfile, CPP_DL_ICE,
 569                "CPP arithmetic must be at least as precise as a target int");
 570
 571   if (CPP_OPTION (pfile, char_precision) < 8)
 572     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 573
 574   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 575     cpp_error (pfile, CPP_DL_ICE,
 576                "target wchar_t is narrower than target char");
 577
 578   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 579     cpp_error (pfile, CPP_DL_ICE,
 580                "target int is narrower than target char");
 581
 582   /* This is assumed in eval_token() and could be fixed if necessary.  */
 583   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 584     cpp_error (pfile, CPP_DL_ICE,
 585                "CPP half-integer narrower than CPP character");
 586
 587   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 588     cpp_error (pfile, CPP_DL_ICE,
 589                "CPP on this host cannot handle wide character constants over"
 590                " %lu bits, but the target requires %lu bits",
 591                (unsigned long) BITS_PER_CPPCHAR_T,
 592                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 593 }
 594 #else
 595 # define sanity_checks(PFILE)
 596 #endif
 597
 598 /* This is called after options have been parsed, and partially
 599    processed.  */
 600 void
 601 cpp_post_options (cpp_reader *pfile)
 602 {
 603   int flags;
 604
 605   sanity_checks (pfile);
 606
 607   post_options (pfile);
 608
 609   /* Mark named operators before handling command line macros.  */
 610   flags = 0;
 611   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 612     flags |= NODE_OPERATOR;
 613   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 614     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 615   if (flags != 0)
 616     mark_named_operators (pfile, flags);
 617 }
 618
 619 /* Setup for processing input from the file named FNAME, or stdin if
 620    it is the empty string.  Return the original filename
 621    on success (e.g. foo.i->foo.c), or NULL on failure.  */
 622 const char *
 623 cpp_read_main_file (cpp_reader *pfile, const char *fname)
 624 {
 625   const source_location loc = 0;
 626
 627   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE)
 628     {
 629       if (!pfile->deps)
 630         pfile->deps = deps_init ();
 631
 632       /* Set the default target (if there is none already).  */
 633       deps_add_default_target (pfile->deps, fname);
 634     }
 635
 636   pfile->main_file
 637     = _cpp_find_file (pfile, fname, &pfile->no_search_path, false, 0, false,
 638                       loc);
 639   if (_cpp_find_failed (pfile->main_file))
 640     return NULL;
 641
 642   _cpp_stack_file (pfile, pfile->main_file, false, loc);
 643
 644   /* For foo.i, read the original filename foo.c now, for the benefit
 645      of the front ends.  */
 646   if (CPP_OPTION (pfile, preprocessed))
 647     {
 648       read_original_filename (pfile);
 649       fname =
 650         ORDINARY_MAP_FILE_NAME
 651         ((LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table)));
 652     }
 653   return fname;
 654 }
 655
 656 /* For preprocessed files, if the first tokens are of the form # NUM.
 657    handle the directive so we know the original file name.  This will
 658    generate file_change callbacks, which the front ends must handle
 659    appropriately given their state of initialization.  */
 660 static void
 661 read_original_filename (cpp_reader *pfile)
 662 {
 663   const cpp_token *token, *token1;
 664
 665   /* Lex ahead; if the first tokens are of the form # NUM, then
 666      process the directive, otherwise back up.  */
 667   token = _cpp_lex_direct (pfile);
 668   if (token->type == CPP_HASH)
 669     {
 670       pfile->state.in_directive = 1;
 671       token1 = _cpp_lex_direct (pfile);
 672       _cpp_backup_tokens (pfile, 1);
 673       pfile->state.in_directive = 0;
 674
 675       /* If it's a #line directive, handle it.  */
 676       if (token1->type == CPP_NUMBER
 677           && _cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 678         {
 679           read_original_directory (pfile);
 680           return;
 681         }
 682     }
 683
 684   /* Backup as if nothing happened.  */
 685   _cpp_backup_tokens (pfile, 1);
 686 }
 687
 688 /* For preprocessed files, if the tokens following the first filename
 689    line is of the form # <line> "/path/name//", handle the
 690    directive so we know the original current directory.  */
 691 static void
 692 read_original_directory (cpp_reader *pfile)
 693 {
 694   const cpp_token *hash, *token;
 695
 696   /* Lex ahead; if the first tokens are of the form # NUM, then
 697      process the directive, otherwise back up.  */
 698   hash = _cpp_lex_direct (pfile);
 699   if (hash->type != CPP_HASH)
 700     {
 701       _cpp_backup_tokens (pfile, 1);
 702       return;
 703     }
 704
 705   token = _cpp_lex_direct (pfile);
 706
 707   if (token->type != CPP_NUMBER)
 708     {
 709       _cpp_backup_tokens (pfile, 2);
 710       return;
 711     }
 712
 713   token = _cpp_lex_direct (pfile);
 714
 715   if (token->type != CPP_STRING
 716       || ! (token->val.str.len >= 5
 717             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-2])
 718             && IS_DIR_SEPARATOR (token->val.str.text[token->val.str.len-3])))
 719     {
 720       _cpp_backup_tokens (pfile, 3);
 721       return;
 722     }
 723
 724   if (pfile->cb.dir_change)
 725     {
 726       char *debugdir = (char *) alloca (token->val.str.len - 3);
 727
 728       memcpy (debugdir, (const char *) token->val.str.text + 1,
 729               token->val.str.len - 4);
 730       debugdir[token->val.str.len - 4] = '\0';
 731
 732       pfile->cb.dir_change (pfile, debugdir);
 733     }
 734 }
 735
 736 /* This is called at the end of preprocessing.  It pops the last
 737    buffer and writes dependency output.
 738
 739    Maybe it should also reset state, such that you could call
 740    cpp_start_read with a new filename to restart processing.  */
 741 void
 742 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 743 {
 744   /* Warn about unused macros before popping the final buffer.  */
 745   if (CPP_OPTION (pfile, warn_unused_macros))
 746     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 747
 748   /* lex.c leaves the final buffer on the stack.  This it so that
 749      it returns an unending stream of CPP_EOFs to the client.  If we
 750      popped the buffer, we'd dereference a NULL buffer pointer and
 751      segfault.  It's nice to allow the client to do worry-free excess
 752      cpp_get_token calls.  */
 753   while (pfile->buffer)
 754     _cpp_pop_buffer (pfile);
 755
 756   if (CPP_OPTION (pfile, deps.style) != DEPS_NONE
 757       && deps_stream)
 758     {
 759       deps_write (pfile->deps, deps_stream, 72);
 760
 761       if (CPP_OPTION (pfile, deps.phony_targets))
 762         deps_phony_targets (pfile->deps, deps_stream);
 763     }
 764
 765   /* Report on headers that could use multiple include guards.  */
 766   if (CPP_OPTION (pfile, print_include_names))
 767     _cpp_report_missing_guards (pfile);
 768 }
 769
 770 static void
 771 post_options (cpp_reader *pfile)
 772 {
 773   /* -Wtraditional is not useful in C++ mode.  */
 774   if (CPP_OPTION (pfile, cplusplus))
 775     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 776
 777   /* Permanently disable macro expansion if we are rescanning
 778      preprocessed text.  Read preprocesed source in ISO mode.  */
 779   if (CPP_OPTION (pfile, preprocessed))
 780     {
 781       if (!CPP_OPTION (pfile, directives_only))
 782         pfile->state.prevent_expansion = 1;
 783       CPP_OPTION (pfile, traditional) = 0;
 784     }
 785
 786   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 787     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 788
 789   if (CPP_OPTION (pfile, traditional))
 790     {
 791       CPP_OPTION (pfile, trigraphs) = 0;
 792       CPP_OPTION (pfile, warn_trigraphs) = 0;
 793     }
 794 }