libcpp/init.c

   1 /* CPP Library.
   2    Copyright (C) 1986-2021 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 bool 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 cxx23_identifiers;
  86   char std;
  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   char utf8_char_literals;
  95   char va_opt;
  96   char scope;
  97   char dfp_constants;
  98   char size_t_literals;
  99   char elifdef;
 100 };
 101
 102 static const struct lang_flags lang_defaults[] =
 103 { /*              c99 c++ xnum xid c11 c++23 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit elifdef */
 104   /* GNUC89   */  { 0,  0,  1,  0,  0,  0,    0,  1,   0,   0,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
 105   /* GNUC99   */  { 1,  0,  1,  1,  0,  0,    0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
 106   /* GNUC11   */  { 1,  0,  1,  1,  1,  0,    0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
 107   /* GNUC17   */  { 1,  0,  1,  1,  1,  0,    0,  1,   1,   1,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
 108   /* GNUC2X   */  { 1,  0,  1,  1,  1,  0,    0,  1,   1,   1,   0,    1,     1,     0,   1,      1,   1,     1,   0,   1 },
 109   /* STDC89   */  { 0,  0,  0,  0,  0,  0,    1,  0,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
 110   /* STDC94   */  { 0,  0,  0,  0,  0,  0,    1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
 111   /* STDC99   */  { 1,  0,  1,  1,  0,  0,    1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
 112   /* STDC11   */  { 1,  0,  1,  1,  1,  0,    1,  1,   1,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
 113   /* STDC17   */  { 1,  0,  1,  1,  1,  0,    1,  1,   1,   0,   0,    0,     0,     1,   0,      0,   0,     0,   0,   0 },
 114   /* STDC2X   */  { 1,  0,  1,  1,  1,  0,    1,  1,   1,   0,   0,    1,     1,     1,   1,      0,   1,     1,   0,   1 },
 115   /* GNUCXX   */  { 0,  1,  1,  1,  0,  0,    0,  1,   0,   0,   0,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
 116   /* CXX98    */  { 0,  1,  0,  1,  0,  0,    1,  1,   0,   0,   0,    0,     0,     1,   0,      0,   1,     0,   0,   0 },
 117   /* GNUCXX11 */  { 1,  1,  1,  1,  1,  0,    0,  1,   1,   1,   1,    0,     0,     0,   0,      1,   1,     0,   0,   0 },
 118   /* CXX11    */  { 1,  1,  0,  1,  1,  0,    1,  1,   1,   1,   1,    0,     0,     1,   0,      0,   1,     0,   0,   0 },
 119   /* GNUCXX14 */  { 1,  1,  1,  1,  1,  0,    0,  1,   1,   1,   1,    1,     1,     0,   0,      1,   1,     0,   0,   0 },
 120   /* CXX14    */  { 1,  1,  0,  1,  1,  0,    1,  1,   1,   1,   1,    1,     1,     1,   0,      0,   1,     0,   0,   0 },
 121   /* GNUCXX17 */  { 1,  1,  1,  1,  1,  0,    0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0 },
 122   /* CXX17    */  { 1,  1,  1,  1,  1,  0,    1,  1,   1,   1,   1,    1,     1,     0,   1,      0,   1,     0,   0,   0 },
 123   /* GNUCXX20 */  { 1,  1,  1,  1,  1,  0,    0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0 },
 124   /* CXX20    */  { 1,  1,  1,  1,  1,  0,    1,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   0,   0 },
 125   /* GNUCXX23 */  { 1,  1,  1,  1,  1,  1,    0,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   1,   1 },
 126   /* CXX23    */  { 1,  1,  1,  1,  1,  1,    1,  1,   1,   1,   1,    1,     1,     0,   1,      1,   1,     0,   1,   1 },
 127   /* ASM      */  { 0,  0,  1,  0,  0,  0,    0,  0,   0,   0,   0,    0,     0,     0,   0,      0,   0,     0,   0,   0 }
 128 };
 129
 130 /* Sets internal flags correctly for a given language.  */
 131 void
 132 cpp_set_lang (cpp_reader *pfile, enum c_lang lang)
 133 {
 134   const struct lang_flags *l = &lang_defaults[(int) lang];
 135
 136   CPP_OPTION (pfile, lang) = lang;
 137
 138   CPP_OPTION (pfile, c99)                        = l->c99;
 139   CPP_OPTION (pfile, cplusplus)                  = l->cplusplus;
 140   CPP_OPTION (pfile, extended_numbers)           = l->extended_numbers;
 141   CPP_OPTION (pfile, extended_identifiers)       = l->extended_identifiers;
 142   CPP_OPTION (pfile, c11_identifiers)            = l->c11_identifiers;
 143   CPP_OPTION (pfile, cxx23_identifiers)          = l->cxx23_identifiers;
 144   CPP_OPTION (pfile, std)                        = l->std;
 145   CPP_OPTION (pfile, digraphs)                   = l->digraphs;
 146   CPP_OPTION (pfile, uliterals)                  = l->uliterals;
 147   CPP_OPTION (pfile, rliterals)                  = l->rliterals;
 148   CPP_OPTION (pfile, user_literals)              = l->user_literals;
 149   CPP_OPTION (pfile, binary_constants)           = l->binary_constants;
 150   CPP_OPTION (pfile, digit_separators)           = l->digit_separators;
 151   CPP_OPTION (pfile, trigraphs)                  = l->trigraphs;
 152   CPP_OPTION (pfile, utf8_char_literals)         = l->utf8_char_literals;
 153   CPP_OPTION (pfile, va_opt)                     = l->va_opt;
 154   CPP_OPTION (pfile, scope)                      = l->scope;
 155   CPP_OPTION (pfile, dfp_constants)              = l->dfp_constants;
 156   CPP_OPTION (pfile, size_t_literals)            = l->size_t_literals;
 157   CPP_OPTION (pfile, elifdef)                    = l->elifdef;
 158 }
 159
 160 /* Initialize library global state.  */
 161 static void
 162 init_library (void)
 163 {
 164   static int initialized = 0;
 165
 166   if (! initialized)
 167     {
 168       initialized = 1;
 169
 170       _cpp_init_lexer ();
 171
 172       /* Set up the trigraph map.  This doesn't need to do anything if
 173          we were compiled with a compiler that supports C99 designated
 174          initializers.  */
 175       init_trigraph_map ();
 176
 177 #ifdef ENABLE_NLS
 178        (void) bindtextdomain (PACKAGE, LOCALEDIR);
 179 #endif
 180     }
 181 }
 182
 183 /* Initialize a cpp_reader structure.  */
 184 cpp_reader *
 185 cpp_create_reader (enum c_lang lang, cpp_hash_table *table,
 186                    class line_maps *line_table)
 187 {
 188   cpp_reader *pfile;
 189
 190   /* Initialize this instance of the library if it hasn't been already.  */
 191   init_library ();
 192
 193   pfile = XCNEW (cpp_reader);
 194   memset (&pfile->base_context, 0, sizeof (pfile->base_context));
 195
 196   cpp_set_lang (pfile, lang);
 197   CPP_OPTION (pfile, warn_multichar) = 1;
 198   CPP_OPTION (pfile, discard_comments) = 1;
 199   CPP_OPTION (pfile, discard_comments_in_macro_exp) = 1;
 200   CPP_OPTION (pfile, max_include_depth) = 200;
 201   CPP_OPTION (pfile, operator_names) = 1;
 202   CPP_OPTION (pfile, warn_trigraphs) = 2;
 203   CPP_OPTION (pfile, warn_endif_labels) = 1;
 204   CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1;
 205   CPP_OPTION (pfile, cpp_warn_c11_c2x_compat) = -1;
 206   CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0;
 207   CPP_OPTION (pfile, cpp_warn_deprecated) = 1;
 208   CPP_OPTION (pfile, cpp_warn_long_long) = 0;
 209   CPP_OPTION (pfile, dollars_in_ident) = 1;
 210   CPP_OPTION (pfile, warn_dollars) = 1;
 211   CPP_OPTION (pfile, warn_variadic_macros) = 1;
 212   CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
 213   CPP_OPTION (pfile, cpp_warn_implicit_fallthrough) = 0;
 214   /* By default, track locations of tokens resulting from macro
 215      expansion.  The '2' means, track the locations with the highest
 216      accuracy.  Read the comments for struct
 217      cpp_options::track_macro_expansion to learn about the other
 218      values.  */
 219   CPP_OPTION (pfile, track_macro_expansion) = 2;
 220   CPP_OPTION (pfile, warn_normalize) = normalized_C;
 221   CPP_OPTION (pfile, warn_literal_suffix) = 1;
 222   CPP_OPTION (pfile, canonical_system_headers)
 223       = ENABLE_CANONICAL_SYSTEM_HEADERS;
 224   CPP_OPTION (pfile, ext_numeric_literals) = 1;
 225   CPP_OPTION (pfile, warn_date_time) = 0;
 226   CPP_OPTION (pfile, cpp_warn_bidirectional) = bidirectional_unpaired;
 227
 228   /* Default CPP arithmetic to something sensible for the host for the
 229      benefit of dumb users like fix-header.  */
 230   CPP_OPTION (pfile, precision) = CHAR_BIT * sizeof (long);
 231   CPP_OPTION (pfile, char_precision) = CHAR_BIT;
 232   CPP_OPTION (pfile, wchar_precision) = CHAR_BIT * sizeof (int);
 233   CPP_OPTION (pfile, int_precision) = CHAR_BIT * sizeof (int);
 234   CPP_OPTION (pfile, unsigned_char) = 0;
 235   CPP_OPTION (pfile, unsigned_wchar) = 1;
 236   CPP_OPTION (pfile, bytes_big_endian) = 1;  /* does not matter */
 237
 238   /* Default to no charset conversion.  */
 239   CPP_OPTION (pfile, narrow_charset) = _cpp_default_encoding ();
 240   CPP_OPTION (pfile, wide_charset) = 0;
 241
 242   /* Default the input character set to UTF-8.  */
 243   CPP_OPTION (pfile, input_charset) = _cpp_default_encoding ();
 244
 245   /* A fake empty "directory" used as the starting point for files
 246      looked up without a search path.  Name cannot be '/' because we
 247      don't want to prepend anything at all to filenames using it.  All
 248      other entries are correct zero-initialized.  */
 249   pfile->no_search_path.name = (char *) "";
 250
 251   /* Initialize the line map.  */
 252   pfile->line_table = line_table;
 253
 254   /* Initialize lexer state.  */
 255   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 256
 257   /* Set up static tokens.  */
 258   pfile->avoid_paste.type = CPP_PADDING;
 259   pfile->avoid_paste.val.source = NULL;
 260   pfile->avoid_paste.src_loc = 0;
 261   pfile->endarg.type = CPP_EOF;
 262   pfile->endarg.flags = 0;
 263   pfile->endarg.src_loc = 0;
 264
 265   /* Create a token buffer for the lexer.  */
 266   _cpp_init_tokenrun (&pfile->base_run, 250);
 267   pfile->cur_run = &pfile->base_run;
 268   pfile->cur_token = pfile->base_run.base;
 269
 270   /* Initialize the base context.  */
 271   pfile->context = &pfile->base_context;
 272   pfile->base_context.c.macro = 0;
 273   pfile->base_context.prev = pfile->base_context.next = 0;
 274
 275   /* Aligned and unaligned storage.  */
 276   pfile->a_buff = _cpp_get_buff (pfile, 0);
 277   pfile->u_buff = _cpp_get_buff (pfile, 0);
 278
 279   /* Initialize table for push_macro/pop_macro.  */
 280   pfile->pushed_macros = 0;
 281
 282   /* Do not force token locations by default.  */
 283   pfile->forced_token_location = 0;
 284
 285   /* Note the timestamp is unset.  */
 286   pfile->time_stamp = time_t (-1);
 287   pfile->time_stamp_kind = 0;
 288
 289   /* The expression parser stack.  */
 290   _cpp_expand_op_stack (pfile);
 291
 292   /* Initialize the buffer obstack.  */
 293   obstack_specify_allocation (&pfile->buffer_ob, 0, 0, xmalloc, free);
 294
 295   _cpp_init_files (pfile);
 296
 297   _cpp_init_hashtable (pfile, table);
 298
 299   return pfile;
 300 }
 301
 302 /* Set the line_table entry in PFILE.  This is called after reading a
 303    PCH file, as the old line_table will be incorrect.  */
 304 void
 305 cpp_set_line_map (cpp_reader *pfile, class line_maps *line_table)
 306 {
 307   pfile->line_table = line_table;
 308 }
 309
 310 /* Free resources used by PFILE.  Accessing PFILE after this function
 311    returns leads to undefined behavior.  Returns the error count.  */
 312 void
 313 cpp_destroy (cpp_reader *pfile)
 314 {
 315   cpp_context *context, *contextn;
 316   struct def_pragma_macro *pmacro;
 317   tokenrun *run, *runn;
 318   int i;
 319
 320   free (pfile->op_stack);
 321
 322   while (CPP_BUFFER (pfile) != NULL)
 323     _cpp_pop_buffer (pfile);
 324
 325   free (pfile->out.base);
 326
 327   if (pfile->macro_buffer)
 328     {
 329       free (pfile->macro_buffer);
 330       pfile->macro_buffer = NULL;
 331       pfile->macro_buffer_len = 0;
 332     }
 333
 334   if (pfile->deps)
 335     deps_free (pfile->deps);
 336   obstack_free (&pfile->buffer_ob, 0);
 337
 338   _cpp_destroy_hashtable (pfile);
 339   _cpp_cleanup_files (pfile);
 340   _cpp_destroy_iconv (pfile);
 341
 342   _cpp_free_buff (pfile->a_buff);
 343   _cpp_free_buff (pfile->u_buff);
 344   _cpp_free_buff (pfile->free_buffs);
 345
 346   for (run = &pfile->base_run; run; run = runn)
 347     {
 348       runn = run->next;
 349       free (run->base);
 350       if (run != &pfile->base_run)
 351         free (run);
 352     }
 353
 354   for (context = pfile->base_context.next; context; context = contextn)
 355     {
 356       contextn = context->next;
 357       free (context);
 358     }
 359
 360   if (pfile->comments.entries)
 361     {
 362       for (i = 0; i < pfile->comments.count; i++)
 363         free (pfile->comments.entries[i].comment);
 364
 365       free (pfile->comments.entries);
 366     }
 367   if (pfile->pushed_macros)
 368     {
 369       do
 370         {
 371           pmacro = pfile->pushed_macros;
 372           pfile->pushed_macros = pmacro->next;
 373           free (pmacro->name);
 374           free (pmacro);
 375         }
 376       while (pfile->pushed_macros);
 377     }
 378
 379   free (pfile);
 380 }
 381
 382 /* This structure defines one built-in identifier.  A node will be
 383    entered in the hash table under the name NAME, with value VALUE.
 384
 385    There are two tables of these.  builtin_array holds all the
 386    "builtin" macros: these are handled by builtin_macro() in
 387    macro.c.  Builtin is somewhat of a misnomer -- the property of
 388    interest is that these macros require special code to compute their
 389    expansions.  The value is a "cpp_builtin_type" enumerator.
 390
 391    operator_array holds the C++ named operators.  These are keywords
 392    which act as aliases for punctuators.  In C++, they cannot be
 393    altered through #define, and #if recognizes them as operators.  In
 394    C, these are not entered into the hash table at all (but see
 395    <iso646.h>).  The value is a token-type enumerator.  */
 396 struct builtin_macro
 397 {
 398   const uchar *const name;
 399   const unsigned short len;
 400   const unsigned short value;
 401   const bool always_warn_if_redefined;
 402 };
 403
 404 #define B(n, t, f)    { DSC(n), t, f }
 405 static const struct builtin_macro builtin_array[] =
 406 {
 407   B("__TIMESTAMP__",     BT_TIMESTAMP,     false),
 408   B("__TIME__",          BT_TIME,          false),
 409   B("__DATE__",          BT_DATE,          false),
 410   B("__FILE__",          BT_FILE,          false),
 411   B("__FILE_NAME__",     BT_FILE_NAME,     false),
 412   B("__BASE_FILE__",     BT_BASE_FILE,     false),
 413   B("__LINE__",          BT_SPECLINE,      true),
 414   B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
 415   B("__COUNTER__",       BT_COUNTER,       true),
 416   /* Make sure to update the list of built-in
 417      function-like macros in traditional.c:
 418      fun_like_macro() when adding more following */
 419   B("__has_attribute",   BT_HAS_ATTRIBUTE, true),
 420   B("__has_c_attribute", BT_HAS_STD_ATTRIBUTE, true),
 421   B("__has_cpp_attribute", BT_HAS_ATTRIBUTE, true),
 422   B("__has_builtin",     BT_HAS_BUILTIN,   true),
 423   B("__has_include",     BT_HAS_INCLUDE,   true),
 424   B("__has_include_next",BT_HAS_INCLUDE_NEXT,   true),
 425   /* Keep builtins not used for -traditional-cpp at the end, and
 426      update init_builtins() if any more are added.  */
 427   B("_Pragma",           BT_PRAGMA,        true),
 428   B("__STDC__",          BT_STDC,          true),
 429 };
 430 #undef B
 431
 432 struct builtin_operator
 433 {
 434   const uchar *const name;
 435   const unsigned short len;
 436   const unsigned short value;
 437 };
 438
 439 #define B(n, t)    { DSC(n), t }
 440 static const struct builtin_operator operator_array[] =
 441 {
 442   B("and",      CPP_AND_AND),
 443   B("and_eq",   CPP_AND_EQ),
 444   B("bitand",   CPP_AND),
 445   B("bitor",    CPP_OR),
 446   B("compl",    CPP_COMPL),
 447   B("not",      CPP_NOT),
 448   B("not_eq",   CPP_NOT_EQ),
 449   B("or",       CPP_OR_OR),
 450   B("or_eq",    CPP_OR_EQ),
 451   B("xor",      CPP_XOR),
 452   B("xor_eq",   CPP_XOR_EQ)
 453 };
 454 #undef B
 455
 456 /* Mark the C++ named operators in the hash table.  */
 457 static void
 458 mark_named_operators (cpp_reader *pfile, int flags)
 459 {
 460   const struct builtin_operator *b;
 461
 462   for (b = operator_array;
 463        b < (operator_array + ARRAY_SIZE (operator_array));
 464        b++)
 465     {
 466       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 467       hp->flags |= flags;
 468       hp->is_directive = 0;
 469       hp->directive_index = b->value;
 470     }
 471 }
 472
 473 /* Helper function of cpp_type2name. Return the string associated with
 474    named operator TYPE.  */
 475 const char *
 476 cpp_named_operator2name (enum cpp_ttype type)
 477 {
 478   const struct builtin_operator *b;
 479
 480   for (b = operator_array;
 481        b < (operator_array + ARRAY_SIZE (operator_array));
 482        b++)
 483     {
 484       if (type == b->value)
 485         return (const char *) b->name;
 486     }
 487
 488   return NULL;
 489 }
 490
 491 void
 492 cpp_init_special_builtins (cpp_reader *pfile)
 493 {
 494   const struct builtin_macro *b;
 495   size_t n = ARRAY_SIZE (builtin_array);
 496
 497   if (CPP_OPTION (pfile, traditional))
 498     n -= 2;
 499   else if (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 500            || CPP_OPTION (pfile, std))
 501     n--;
 502
 503   for (b = builtin_array; b < builtin_array + n; b++)
 504     {
 505       if ((b->value == BT_HAS_ATTRIBUTE
 506            || b->value == BT_HAS_STD_ATTRIBUTE
 507            || b->value == BT_HAS_BUILTIN)
 508           && (CPP_OPTION (pfile, lang) == CLK_ASM
 509               || pfile->cb.has_attribute == NULL))
 510         continue;
 511       cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 512       hp->type = NT_BUILTIN_MACRO;
 513       if (b->always_warn_if_redefined)
 514         hp->flags |= NODE_WARN;
 515       hp->value.builtin = (enum cpp_builtin_type) b->value;
 516     }
 517 }
 518
 519 /* Restore macro C to builtin macro definition.  */
 520
 521 void
 522 _cpp_restore_special_builtin (cpp_reader *pfile, struct def_pragma_macro *c)
 523 {
 524   size_t len = strlen (c->name);
 525
 526   for (const struct builtin_macro *b = builtin_array;
 527        b < builtin_array + ARRAY_SIZE (builtin_array); b++)
 528     if (b->len == len && memcmp (c->name, b->name, len + 1) == 0)
 529       {
 530         cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
 531         hp->type = NT_BUILTIN_MACRO;
 532         if (b->always_warn_if_redefined)
 533           hp->flags |= NODE_WARN;
 534         hp->value.builtin = (enum cpp_builtin_type) b->value;
 535       }
 536 }
 537
 538 /* Read the builtins table above and enter them, and language-specific
 539    macros, into the hash table.  HOSTED is true if this is a hosted
 540    environment.  */
 541 void
 542 cpp_init_builtins (cpp_reader *pfile, int hosted)
 543 {
 544   cpp_init_special_builtins (pfile);
 545
 546   if (!CPP_OPTION (pfile, traditional)
 547       && (! CPP_OPTION (pfile, stdc_0_in_system_headers)
 548           || CPP_OPTION (pfile, std)))
 549     _cpp_define_builtin (pfile, "__STDC__ 1");
 550
 551   if (CPP_OPTION (pfile, cplusplus))
 552     {
 553       /* C++23 is not yet a standard.  For now, use an invalid
 554        * year/month, 202100L, which is larger than 202002L.  */
 555       if (CPP_OPTION (pfile, lang) == CLK_CXX23
 556           || CPP_OPTION (pfile, lang) == CLK_GNUCXX23)
 557         _cpp_define_builtin (pfile, "__cplusplus 202100L");
 558       else if (CPP_OPTION (pfile, lang) == CLK_CXX20
 559           || CPP_OPTION (pfile, lang) == CLK_GNUCXX20)
 560         _cpp_define_builtin (pfile, "__cplusplus 202002L");
 561       else if (CPP_OPTION (pfile, lang) == CLK_CXX17
 562           || CPP_OPTION (pfile, lang) == CLK_GNUCXX17)
 563         _cpp_define_builtin (pfile, "__cplusplus 201703L");
 564       else if (CPP_OPTION (pfile, lang) == CLK_CXX14
 565           || CPP_OPTION (pfile, lang) == CLK_GNUCXX14)
 566         _cpp_define_builtin (pfile, "__cplusplus 201402L");
 567       else if (CPP_OPTION (pfile, lang) == CLK_CXX11
 568                || CPP_OPTION (pfile, lang) == CLK_GNUCXX11)
 569         _cpp_define_builtin (pfile, "__cplusplus 201103L");
 570       else
 571         _cpp_define_builtin (pfile, "__cplusplus 199711L");
 572     }
 573   else if (CPP_OPTION (pfile, lang) == CLK_ASM)
 574     _cpp_define_builtin (pfile, "__ASSEMBLER__ 1");
 575   else if (CPP_OPTION (pfile, lang) == CLK_STDC94)
 576     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199409L");
 577   else if (CPP_OPTION (pfile, lang) == CLK_STDC2X
 578            || CPP_OPTION (pfile, lang) == CLK_GNUC2X)
 579     _cpp_define_builtin (pfile, "__STDC_VERSION__ 202000L");
 580   else if (CPP_OPTION (pfile, lang) == CLK_STDC17
 581            || CPP_OPTION (pfile, lang) == CLK_GNUC17)
 582     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201710L");
 583   else if (CPP_OPTION (pfile, lang) == CLK_STDC11
 584            || CPP_OPTION (pfile, lang) == CLK_GNUC11)
 585     _cpp_define_builtin (pfile, "__STDC_VERSION__ 201112L");
 586   else if (CPP_OPTION (pfile, c99))
 587     _cpp_define_builtin (pfile, "__STDC_VERSION__ 199901L");
 588
 589   if (CPP_OPTION (pfile, uliterals)
 590       && !(CPP_OPTION (pfile, cplusplus)
 591            && (CPP_OPTION (pfile, lang) == CLK_GNUCXX
 592             || CPP_OPTION (pfile, lang) == CLK_CXX98)))
 593     {
 594       _cpp_define_builtin (pfile, "__STDC_UTF_16__ 1");
 595       _cpp_define_builtin (pfile, "__STDC_UTF_32__ 1");
 596     }
 597
 598   if (hosted)
 599     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 1");
 600   else
 601     _cpp_define_builtin (pfile, "__STDC_HOSTED__ 0");
 602
 603   if (CPP_OPTION (pfile, objc))
 604     _cpp_define_builtin (pfile, "__OBJC__ 1");
 605 }
 606
 607 /* Sanity-checks are dependent on command-line options, so it is
 608    called as a subroutine of cpp_read_main_file.  */
 609 #if CHECKING_P
 610 static void sanity_checks (cpp_reader *);
 611 static void sanity_checks (cpp_reader *pfile)
 612 {
 613   cppchar_t test = 0;
 614   size_t max_precision = 2 * CHAR_BIT * sizeof (cpp_num_part);
 615
 616   /* Sanity checks for assumptions about CPP arithmetic and target
 617      type precisions made by cpplib.  */
 618   test--;
 619   if (test < 1)
 620     cpp_error (pfile, CPP_DL_ICE, "cppchar_t must be an unsigned type");
 621
 622   if (CPP_OPTION (pfile, precision) > max_precision)
 623     cpp_error (pfile, CPP_DL_ICE,
 624                "preprocessor arithmetic has maximum precision of %lu bits;"
 625                " target requires %lu bits",
 626                (unsigned long) max_precision,
 627                (unsigned long) CPP_OPTION (pfile, precision));
 628
 629   if (CPP_OPTION (pfile, precision) < CPP_OPTION (pfile, int_precision))
 630     cpp_error (pfile, CPP_DL_ICE,
 631                "CPP arithmetic must be at least as precise as a target int");
 632
 633   if (CPP_OPTION (pfile, char_precision) < 8)
 634     cpp_error (pfile, CPP_DL_ICE, "target char is less than 8 bits wide");
 635
 636   if (CPP_OPTION (pfile, wchar_precision) < CPP_OPTION (pfile, char_precision))
 637     cpp_error (pfile, CPP_DL_ICE,
 638                "target wchar_t is narrower than target char");
 639
 640   if (CPP_OPTION (pfile, int_precision) < CPP_OPTION (pfile, char_precision))
 641     cpp_error (pfile, CPP_DL_ICE,
 642                "target int is narrower than target char");
 643
 644   /* This is assumed in eval_token() and could be fixed if necessary.  */
 645   if (sizeof (cppchar_t) > sizeof (cpp_num_part))
 646     cpp_error (pfile, CPP_DL_ICE,
 647                "CPP half-integer narrower than CPP character");
 648
 649   if (CPP_OPTION (pfile, wchar_precision) > BITS_PER_CPPCHAR_T)
 650     cpp_error (pfile, CPP_DL_ICE,
 651                "CPP on this host cannot handle wide character constants over"
 652                " %lu bits, but the target requires %lu bits",
 653                (unsigned long) BITS_PER_CPPCHAR_T,
 654                (unsigned long) CPP_OPTION (pfile, wchar_precision));
 655 }
 656 #else
 657 # define sanity_checks(PFILE)
 658 #endif
 659
 660 /* This is called after options have been parsed, and partially
 661    processed.  */
 662 void
 663 cpp_post_options (cpp_reader *pfile)
 664 {
 665   int flags;
 666
 667   sanity_checks (pfile);
 668
 669   post_options (pfile);
 670
 671   /* Mark named operators before handling command line macros.  */
 672   flags = 0;
 673   if (CPP_OPTION (pfile, cplusplus) && CPP_OPTION (pfile, operator_names))
 674     flags |= NODE_OPERATOR;
 675   if (CPP_OPTION (pfile, warn_cxx_operator_names))
 676     flags |= NODE_DIAGNOSTIC | NODE_WARN_OPERATOR;
 677   if (flags != 0)
 678     mark_named_operators (pfile, flags);
 679 }
 680
 681 /* Setup for processing input from the file named FNAME, or stdin if
 682    it is the empty string.  Return the original filename on success
 683    (e.g. foo.i->foo.c), or NULL on failure.  INJECTING is true if
 684    there may be injected headers before line 1 of the main file.  */
 685 const char *
 686 cpp_read_main_file (cpp_reader *pfile, const char *fname, bool injecting)
 687 {
 688   if (mkdeps *deps = cpp_get_deps (pfile))
 689     /* Set the default target (if there is none already).  */
 690     deps_add_default_target (deps, fname);
 691
 692   pfile->main_file
 693     = _cpp_find_file (pfile, fname,
 694                       CPP_OPTION (pfile, preprocessed) ? &pfile->no_search_path
 695                       : CPP_OPTION (pfile, main_search) == CMS_user
 696                       ? pfile->quote_include
 697                       : CPP_OPTION (pfile, main_search) == CMS_system
 698                       ? pfile->bracket_include : &pfile->no_search_path,
 699                       /*angle=*/0, _cpp_FFK_NORMAL, 0);
 700
 701   if (_cpp_find_failed (pfile->main_file))
 702     return NULL;
 703
 704   _cpp_stack_file (pfile, pfile->main_file,
 705                    injecting || CPP_OPTION (pfile, preprocessed)
 706                    ? IT_PRE_MAIN : IT_MAIN, 0);
 707
 708   /* For foo.i, read the original filename foo.c now, for the benefit
 709      of the front ends.  */
 710   if (CPP_OPTION (pfile, preprocessed))
 711     if (!read_original_filename (pfile))
 712       {
 713         /* We're on line 1 after all.  */
 714         auto *last = linemap_check_ordinary
 715           (LINEMAPS_LAST_MAP (pfile->line_table, false));
 716         last->to_line = 1;
 717         /* Inform of as-if a file change.  */
 718         _cpp_do_file_change (pfile, LC_RENAME_VERBATIM, LINEMAP_FILE (last),
 719                              LINEMAP_LINE (last), LINEMAP_SYSP (last));
 720       }
 721
 722   auto *map = LINEMAPS_LAST_ORDINARY_MAP (pfile->line_table);
 723   pfile->main_loc = MAP_START_LOCATION (map);
 724
 725   return ORDINARY_MAP_FILE_NAME (map);
 726 }
 727
 728 location_t
 729 cpp_main_loc (const cpp_reader *pfile)
 730 {
 731   return pfile->main_loc;
 732 }
 733
 734 /* For preprocessed files, if the very first characters are
 735    '#<SPACE>[01]<SPACE>', then handle a line directive so we know the
 736    original file name.  This will generate file_change callbacks,
 737    which the front ends must handle appropriately given their state of
 738    initialization.  We peek directly into the character buffer, so
 739    that we're not confused by otherwise-skipped white space &
 740    comments.  We can be very picky, because this should have been
 741    machine-generated text (by us, no less).  This way we do not
 742    interfere with the module directive state machine.  */
 743
 744 static bool
 745 read_original_filename (cpp_reader *pfile)
 746 {
 747   auto *buf = pfile->buffer->next_line;
 748
 749   if (pfile->buffer->rlimit - buf > 4
 750       && buf[0] == '#'
 751       && buf[1] == ' '
 752       // Also permit '1', as that's what used to be here
 753       && (buf[2] == '0' || buf[2] == '1')
 754       && buf[3] == ' ')
 755     {
 756       const cpp_token *token = _cpp_lex_direct (pfile);
 757       gcc_checking_assert (token->type == CPP_HASH);
 758       if (_cpp_handle_directive (pfile, token->flags & PREV_WHITE))
 759         {
 760           read_original_directory (pfile);
 761
 762           auto *penult = &linemap_check_ordinary
 763             (LINEMAPS_LAST_MAP (pfile->line_table, false))[-1];
 764           if (penult[1].reason == LC_RENAME_VERBATIM)
 765             {
 766               /* Expunge any evidence of the original linemap.  */
 767               pfile->line_table->highest_location
 768                 = pfile->line_table->highest_line
 769                 = penult[0].start_location;
 770
 771               penult[1].start_location = penult[0].start_location;
 772               penult[1].reason = penult[0].reason;
 773               penult[0] = penult[1];
 774               pfile->line_table->info_ordinary.used--;
 775               pfile->line_table->info_ordinary.cache = 0;
 776             }
 777
 778           return true;
 779         }
 780     }
 781
 782   return false;
 783 }
 784
 785 /* For preprocessed files, if the tokens following the first filename
 786    line is of the form # <line> "/path/name//", handle the
 787    directive so we know the original current directory.
 788
 789    As with the first line peeking, we can do this without lexing by
 790    being picky.  */
 791 static void
 792 read_original_directory (cpp_reader *pfile)
 793 {
 794   auto *buf = pfile->buffer->next_line;
 795
 796   if (pfile->buffer->rlimit - buf > 4
 797       && buf[0] == '#'
 798       && buf[1] == ' '
 799       // Also permit '1', as that's what used to be here
 800       && (buf[2] == '0' || buf[2] == '1')
 801       && buf[3] == ' ')
 802     {
 803       const cpp_token *hash = _cpp_lex_direct (pfile);
 804       gcc_checking_assert (hash->type == CPP_HASH);
 805       pfile->state.in_directive = 1;
 806       const cpp_token *number = _cpp_lex_direct (pfile);
 807       gcc_checking_assert (number->type == CPP_NUMBER);
 808       const cpp_token *string = _cpp_lex_direct (pfile);
 809       pfile->state.in_directive = 0;
 810
 811       const unsigned char *text = nullptr;
 812       size_t len = 0;
 813       if (string->type == CPP_STRING)
 814         {
 815           /* The string value includes the quotes.  */
 816           text = string->val.str.text;
 817           len = string->val.str.len;
 818         }
 819       if (len < 5
 820           || !IS_DIR_SEPARATOR (text[len - 2])
 821           || !IS_DIR_SEPARATOR (text[len - 3]))
 822         {
 823           /* That didn't work out, back out.   */
 824           _cpp_backup_tokens (pfile, 3);
 825           return;
 826         }
 827
 828       if (pfile->cb.dir_change)
 829         {
 830           /* Smash the string directly, it's dead at this point  */
 831           char *smashy = (char *)text;
 832           smashy[len - 3] = 0;
 833
 834           pfile->cb.dir_change (pfile, smashy + 1);
 835         }
 836
 837       /* We should be at EOL.  */
 838     }
 839 }
 840
 841 /* This is called at the end of preprocessing.  It pops the last
 842    buffer and writes dependency output.
 843
 844    Maybe it should also reset state, such that you could call
 845    cpp_start_read with a new filename to restart processing.  */
 846 void
 847 cpp_finish (cpp_reader *pfile, FILE *deps_stream)
 848 {
 849   /* Warn about unused macros before popping the final buffer.  */
 850   if (CPP_OPTION (pfile, warn_unused_macros))
 851     cpp_forall_identifiers (pfile, _cpp_warn_if_unused_macro, NULL);
 852
 853   /* lex.c leaves the final buffer on the stack.  This it so that
 854      it returns an unending stream of CPP_EOFs to the client.  If we
 855      popped the buffer, we'd dereference a NULL buffer pointer and
 856      segfault.  It's nice to allow the client to do worry-free excess
 857      cpp_get_token calls.  */
 858   while (pfile->buffer)
 859     _cpp_pop_buffer (pfile);
 860
 861   if (deps_stream)
 862     deps_write (pfile, deps_stream, 72);
 863
 864   /* Report on headers that could use multiple include guards.  */
 865   if (CPP_OPTION (pfile, print_include_names))
 866     _cpp_report_missing_guards (pfile);
 867 }
 868
 869 static void
 870 post_options (cpp_reader *pfile)
 871 {
 872   /* -Wtraditional is not useful in C++ mode.  */
 873   if (CPP_OPTION (pfile, cplusplus))
 874     CPP_OPTION (pfile, cpp_warn_traditional) = 0;
 875
 876   /* Permanently disable macro expansion if we are rescanning
 877      preprocessed text.  Read preprocesed source in ISO mode.  */
 878   if (CPP_OPTION (pfile, preprocessed))
 879     {
 880       if (!CPP_OPTION (pfile, directives_only))
 881         pfile->state.prevent_expansion = 1;
 882       CPP_OPTION (pfile, traditional) = 0;
 883     }
 884
 885   if (CPP_OPTION (pfile, warn_trigraphs) == 2)
 886     CPP_OPTION (pfile, warn_trigraphs) = !CPP_OPTION (pfile, trigraphs);
 887
 888   if (CPP_OPTION (pfile, traditional))
 889     {
 890       CPP_OPTION (pfile, trigraphs) = 0;
 891       CPP_OPTION (pfile, warn_trigraphs) = 0;
 892     }
 893
 894   if (CPP_OPTION (pfile, module_directives))
 895     {
 896       /* These unspellable tokens have a leading space.  */
 897       const char *const inits[spec_nodes::M_HWM]
 898         = {"export ", "module ", "import ", "__import"};
 899
 900       for (int ix = 0; ix != spec_nodes::M_HWM; ix++)
 901         {
 902           cpp_hashnode *node = cpp_lookup (pfile, UC (inits[ix]),
 903                                            strlen (inits[ix]));
 904
 905           /* Token we pass to the compiler.  */
 906           pfile->spec_nodes.n_modules[ix][1] = node;
 907
 908           if (ix != spec_nodes::M__IMPORT)
 909             /* Token we recognize when lexing, drop the trailing ' '.  */
 910             node = cpp_lookup (pfile, NODE_NAME (node), NODE_LEN (node) - 1);
 911
 912           node->flags |= NODE_MODULE;
 913           pfile->spec_nodes.n_modules[ix][0] = node;
 914         }
 915     }
 916 }