libcpp/directives.c

   1 /* CPP Library. (Directive handling.)
   2    Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    1999, 2000, 2001, 2002, 2003, 2004, 2005,
   4    2007, 2008, 2009 Free Software Foundation, Inc.
   5    Contributed by Per Bothner, 1994-95.
   6    Based on CCCP program by Paul Rubin, June 1986
   7    Adapted to ANSI C, Richard Stallman, Jan 1987
   8
   9 This program is free software; you can redistribute it and/or modify it
  10 under the terms of the GNU General Public License as published by the
  11 Free Software Foundation; either version 3, or (at your option) any
  12 later version.
  13
  14 This program is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with this program; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "cpplib.h"
  26 #include "internal.h"
  27 #include "mkdeps.h"
  28 #include "obstack.h"
  29
  30 /* Stack of conditionals currently in progress
  31    (including both successful and failing conditionals).  */
  32 struct if_stack
  33 {
  34   struct if_stack *next;
  35   linenum_type line;            /* Line where condition started.  */
  36   const cpp_hashnode *mi_cmacro;/* macro name for #ifndef around entire file */
  37   bool skip_elses;              /* Can future #else / #elif be skipped?  */
  38   bool was_skipping;            /* If were skipping on entry.  */
  39   int type;                     /* Most recent conditional for diagnostics.  */
  40 };
  41
  42 /* Contains a registered pragma or pragma namespace.  */
  43 typedef void (*pragma_cb) (cpp_reader *);
  44 struct pragma_entry
  45 {
  46   struct pragma_entry *next;
  47   const cpp_hashnode *pragma;   /* Name and length.  */
  48   bool is_nspace;
  49   bool is_internal;
  50   bool is_deferred;
  51   bool allow_expansion;
  52   union {
  53     pragma_cb handler;
  54     struct pragma_entry *space;
  55     unsigned int ident;
  56   } u;
  57 };
  58
  59 /* Values for the origin field of struct directive.  KANDR directives
  60    come from traditional (K&R) C.  STDC89 directives come from the
  61    1989 C standard.  EXTENSION directives are extensions.  */
  62 #define KANDR           0
  63 #define STDC89          1
  64 #define EXTENSION       2
  65
  66 /* Values for the flags field of struct directive.  COND indicates a
  67    conditional; IF_COND an opening conditional.  INCL means to treat
  68    "..." and <...> as q-char and h-char sequences respectively.  IN_I
  69    means this directive should be handled even if -fpreprocessed is in
  70    effect (these are the directives with callback hooks).
  71
  72    EXPAND is set on directives that are always macro-expanded.  */
  73 #define COND            (1 << 0)
  74 #define IF_COND         (1 << 1)
  75 #define INCL            (1 << 2)
  76 #define IN_I            (1 << 3)
  77 #define EXPAND          (1 << 4)
  78 #define DEPRECATED      (1 << 5)
  79
  80 /* Defines one #-directive, including how to handle it.  */
  81 typedef void (*directive_handler) (cpp_reader *);
  82 typedef struct directive directive;
  83 struct directive
  84 {
  85   directive_handler handler;    /* Function to handle directive.  */
  86   const uchar *name;            /* Name of directive.  */
  87   unsigned short length;        /* Length of name.  */
  88   unsigned char origin;         /* Origin of directive.  */
  89   unsigned char flags;          /* Flags describing this directive.  */
  90 };
  91
  92 /* Forward declarations.  */
  93
  94 static void skip_rest_of_line (cpp_reader *);
  95 static void check_eol (cpp_reader *, bool);
  96 static void start_directive (cpp_reader *);
  97 static void prepare_directive_trad (cpp_reader *);
  98 static void end_directive (cpp_reader *, int);
  99 static void directive_diagnostics (cpp_reader *, const directive *, int);
 100 static void run_directive (cpp_reader *, int, const char *, size_t);
 101 static char *glue_header_name (cpp_reader *);
 102 static const char *parse_include (cpp_reader *, int *, const cpp_token ***,
 103                                   source_location *);
 104 static void push_conditional (cpp_reader *, int, int, const cpp_hashnode *);
 105 static unsigned int read_flag (cpp_reader *, unsigned int);
 106 static bool strtolinenum (const uchar *, size_t, linenum_type *, bool *);
 107 static void do_diagnostic (cpp_reader *, int, int);
 108 static cpp_hashnode *lex_macro_node (cpp_reader *, bool);
 109 static int undefine_macros (cpp_reader *, cpp_hashnode *, void *);
 110 static void do_include_common (cpp_reader *, enum include_type);
 111 static struct pragma_entry *lookup_pragma_entry (struct pragma_entry *,
 112                                                  const cpp_hashnode *);
 113 static int count_registered_pragmas (struct pragma_entry *);
 114 static char ** save_registered_pragmas (struct pragma_entry *, char **);
 115 static char ** restore_registered_pragmas (cpp_reader *, struct pragma_entry *,
 116                                            char **);
 117 static void do_pragma_once (cpp_reader *);
 118 static void do_pragma_poison (cpp_reader *);
 119 static void do_pragma_system_header (cpp_reader *);
 120 static void do_pragma_dependency (cpp_reader *);
 121 static void do_linemarker (cpp_reader *);
 122 static const cpp_token *get_token_no_padding (cpp_reader *);
 123 static const cpp_token *get__Pragma_string (cpp_reader *);
 124 static void destringize_and_run (cpp_reader *, const cpp_string *);
 125 static int parse_answer (cpp_reader *, struct answer **, int, source_location);
 126 static cpp_hashnode *parse_assertion (cpp_reader *, struct answer **, int);
 127 static struct answer ** find_answer (cpp_hashnode *, const struct answer *);
 128 static void handle_assertion (cpp_reader *, const char *, int);
 129
 130 /* This is the table of directive handlers.  It is ordered by
 131    frequency of occurrence; the numbers at the end are directive
 132    counts from all the source code I have lying around (egcs and libc
 133    CVS as of 1999-05-18, plus grub-0.5.91, linux-2.2.9, and
 134    pcmcia-cs-3.0.9).  This is no longer important as directive lookup
 135    is now O(1).  All extensions other than #warning, #include_next,
 136    and #import are deprecated.  The name is where the extension
 137    appears to have come from.  */
 138
 139 #define DIRECTIVE_TABLE                                                 \
 140 D(define,       T_DEFINE = 0,   KANDR,     IN_I)           /* 270554 */ \
 141 D(include,      T_INCLUDE,      KANDR,     INCL | EXPAND)  /*  52262 */ \
 142 D(endif,        T_ENDIF,        KANDR,     COND)           /*  45855 */ \
 143 D(ifdef,        T_IFDEF,        KANDR,     COND | IF_COND) /*  22000 */ \
 144 D(if,           T_IF,           KANDR, COND | IF_COND | EXPAND) /*  18162 */ \
 145 D(else,         T_ELSE,         KANDR,     COND)           /*   9863 */ \
 146 D(ifndef,       T_IFNDEF,       KANDR,     COND | IF_COND) /*   9675 */ \
 147 D(undef,        T_UNDEF,        KANDR,     IN_I)           /*   4837 */ \
 148 D(line,         T_LINE,         KANDR,     EXPAND)         /*   2465 */ \
 149 D(elif,         T_ELIF,         STDC89,    COND | EXPAND)  /*    610 */ \
 150 D(error,        T_ERROR,        STDC89,    0)              /*    475 */ \
 151 D(pragma,       T_PRAGMA,       STDC89,    IN_I)           /*    195 */ \
 152 D(warning,      T_WARNING,      EXTENSION, 0)              /*     22 */ \
 153 D(include_next, T_INCLUDE_NEXT, EXTENSION, INCL | EXPAND)  /*     19 */ \
 154 D(ident,        T_IDENT,        EXTENSION, IN_I | DEPRECATED) /*     11 */ \
 155 D(import,       T_IMPORT,       EXTENSION, INCL | EXPAND)  /* 0 ObjC */ \
 156 D(assert,       T_ASSERT,       EXTENSION, DEPRECATED)     /* 0 SVR4 */ \
 157 D(unassert,     T_UNASSERT,     EXTENSION, DEPRECATED)     /* 0 SVR4 */ \
 158 D(sccs,         T_SCCS,         EXTENSION, IN_I | DEPRECATED) /* 0 SVR4? */
 159
 160 /* #sccs is synonymous with #ident.  */
 161 #define do_sccs do_ident
 162
 163 /* Use the table to generate a series of prototypes, an enum for the
 164    directive names, and an array of directive handlers.  */
 165
 166 #define D(name, t, o, f) static void do_##name (cpp_reader *);
 167 DIRECTIVE_TABLE
 168 #undef D
 169
 170 #define D(n, tag, o, f) tag,
 171 enum
 172 {
 173   DIRECTIVE_TABLE
 174   N_DIRECTIVES
 175 };
 176 #undef D
 177
 178 #define D(name, t, origin, flags) \
 179 { do_##name, (const uchar *) #name, \
 180   sizeof #name - 1, origin, flags },
 181 static const directive dtable[] =
 182 {
 183 DIRECTIVE_TABLE
 184 };
 185 #undef D
 186 #undef DIRECTIVE_TABLE
 187
 188 /* Wrapper struct directive for linemarkers.
 189    The origin is more or less true - the original K+R cpp
 190    did use this notation in its preprocessed output.  */
 191 static const directive linemarker_dir =
 192 {
 193   do_linemarker, UC"#", 1, KANDR, IN_I
 194 };
 195
 196 #define SEEN_EOL() (pfile->cur_token[-1].type == CPP_EOF)
 197
 198 /* Skip any remaining tokens in a directive.  */
 199 static void
 200 skip_rest_of_line (cpp_reader *pfile)
 201 {
 202   /* Discard all stacked contexts.  */
 203   while (pfile->context->prev)
 204     _cpp_pop_context (pfile);
 205
 206   /* Sweep up all tokens remaining on the line.  */
 207   if (! SEEN_EOL ())
 208     while (_cpp_lex_token (pfile)->type != CPP_EOF)
 209       ;
 210 }
 211
 212 /* Ensure there are no stray tokens at the end of a directive.  If
 213    EXPAND is true, tokens macro-expanding to nothing are allowed.  */
 214 static void
 215 check_eol (cpp_reader *pfile, bool expand)
 216 {
 217   if (! SEEN_EOL () && (expand
 218                         ? cpp_get_token (pfile)
 219                         : _cpp_lex_token (pfile))->type != CPP_EOF)
 220     cpp_error (pfile, CPP_DL_PEDWARN, "extra tokens at end of #%s directive",
 221                pfile->directive->name);
 222 }
 223
 224 /* Ensure there are no stray tokens other than comments at the end of
 225    a directive, and gather the comments.  */
 226 static const cpp_token **
 227 check_eol_return_comments (cpp_reader *pfile)
 228 {
 229   size_t c;
 230   size_t capacity = 8;
 231   const cpp_token **buf;
 232
 233   buf = XNEWVEC (const cpp_token *, capacity);
 234   c = 0;
 235   if (! SEEN_EOL ())
 236     {
 237       while (1)
 238         {
 239           const cpp_token *tok;
 240
 241           tok = _cpp_lex_token (pfile);
 242           if (tok->type == CPP_EOF)
 243             break;
 244           if (tok->type != CPP_COMMENT)
 245             cpp_error (pfile, CPP_DL_PEDWARN,
 246                        "extra tokens at end of #%s directive",
 247                        pfile->directive->name);
 248           else
 249             {
 250               if (c + 1 >= capacity)
 251                 {
 252                   capacity *= 2;
 253                   buf = XRESIZEVEC (const cpp_token *, buf, capacity);
 254                 }
 255               buf[c] = tok;
 256               ++c;
 257             }
 258         }
 259     }
 260   buf[c] = NULL;
 261   return buf;
 262 }
 263
 264 /* Called when entering a directive, _Pragma or command-line directive.  */
 265 static void
 266 start_directive (cpp_reader *pfile)
 267 {
 268   /* Setup in-directive state.  */
 269   pfile->state.in_directive = 1;
 270   pfile->state.save_comments = 0;
 271   pfile->directive_result.type = CPP_PADDING;
 272
 273   /* Some handlers need the position of the # for diagnostics.  */
 274   pfile->directive_line = pfile->line_table->highest_line;
 275 }
 276
 277 /* Called when leaving a directive, _Pragma or command-line directive.  */
 278 static void
 279 end_directive (cpp_reader *pfile, int skip_line)
 280 {
 281   if (pfile->state.in_deferred_pragma)
 282     ;
 283   else if (CPP_OPTION (pfile, traditional))
 284     {
 285       /* Revert change of prepare_directive_trad.  */
 286       pfile->state.prevent_expansion--;
 287
 288       if (pfile->directive != &dtable[T_DEFINE])
 289         _cpp_remove_overlay (pfile);
 290     }
 291   /* We don't skip for an assembler #.  */
 292   else if (skip_line)
 293     {
 294       skip_rest_of_line (pfile);
 295       if (!pfile->keep_tokens)
 296         {
 297           pfile->cur_run = &pfile->base_run;
 298           pfile->cur_token = pfile->base_run.base;
 299         }
 300     }
 301
 302   /* Restore state.  */
 303   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 304   pfile->state.in_directive = 0;
 305   pfile->state.in_expression = 0;
 306   pfile->state.angled_headers = 0;
 307   pfile->directive = 0;
 308 }
 309
 310 /* Prepare to handle the directive in pfile->directive.  */
 311 static void
 312 prepare_directive_trad (cpp_reader *pfile)
 313 {
 314   if (pfile->directive != &dtable[T_DEFINE])
 315     {
 316       bool no_expand = (pfile->directive
 317                         && ! (pfile->directive->flags & EXPAND));
 318       bool was_skipping = pfile->state.skipping;
 319
 320       pfile->state.in_expression = (pfile->directive == &dtable[T_IF]
 321                                     || pfile->directive == &dtable[T_ELIF]);
 322       if (pfile->state.in_expression)
 323         pfile->state.skipping = false;
 324
 325       if (no_expand)
 326         pfile->state.prevent_expansion++;
 327       _cpp_scan_out_logical_line (pfile, NULL);
 328       if (no_expand)
 329         pfile->state.prevent_expansion--;
 330
 331       pfile->state.skipping = was_skipping;
 332       _cpp_overlay_buffer (pfile, pfile->out.base,
 333                            pfile->out.cur - pfile->out.base);
 334     }
 335
 336   /* Stop ISO C from expanding anything.  */
 337   pfile->state.prevent_expansion++;
 338 }
 339
 340 /* Output diagnostics for a directive DIR.  INDENTED is nonzero if
 341    the '#' was indented.  */
 342 static void
 343 directive_diagnostics (cpp_reader *pfile, const directive *dir, int indented)
 344 {
 345   /* Issue -pedantic or deprecated warnings for extensions.  We let
 346      -pedantic take precedence if both are applicable.  */
 347   if (! pfile->state.skipping)
 348     {
 349       if (dir->origin == EXTENSION
 350           && !(dir == &dtable[T_IMPORT] && CPP_OPTION (pfile, objc))
 351           && CPP_PEDANTIC (pfile))
 352         cpp_error (pfile, CPP_DL_PEDWARN, "#%s is a GCC extension", dir->name);
 353       else if (((dir->flags & DEPRECATED) != 0
 354                 || (dir == &dtable[T_IMPORT] && !CPP_OPTION (pfile, objc)))
 355                && CPP_OPTION (pfile, warn_deprecated))
 356         cpp_error (pfile, CPP_DL_WARNING, "#%s is a deprecated GCC extension",
 357                    dir->name);
 358     }
 359
 360   /* Traditionally, a directive is ignored unless its # is in
 361      column 1.  Therefore in code intended to work with K+R
 362      compilers, directives added by C89 must have their #
 363      indented, and directives present in traditional C must not.
 364      This is true even of directives in skipped conditional
 365      blocks.  #elif cannot be used at all.  */
 366   if (CPP_WTRADITIONAL (pfile))
 367     {
 368       if (dir == &dtable[T_ELIF])
 369         cpp_error (pfile, CPP_DL_WARNING,
 370                    "suggest not using #elif in traditional C");
 371       else if (indented && dir->origin == KANDR)
 372         cpp_error (pfile, CPP_DL_WARNING,
 373                    "traditional C ignores #%s with the # indented",
 374                    dir->name);
 375       else if (!indented && dir->origin != KANDR)
 376         cpp_error (pfile, CPP_DL_WARNING,
 377                    "suggest hiding #%s from traditional C with an indented #",
 378                    dir->name);
 379     }
 380 }
 381
 382 /* Check if we have a known directive.  INDENTED is nonzero if the
 383    '#' of the directive was indented.  This function is in this file
 384    to save unnecessarily exporting dtable etc. to lex.c.  Returns
 385    nonzero if the line of tokens has been handled, zero if we should
 386    continue processing the line.  */
 387 int
 388 _cpp_handle_directive (cpp_reader *pfile, int indented)
 389 {
 390   const directive *dir = 0;
 391   const cpp_token *dname;
 392   bool was_parsing_args = pfile->state.parsing_args;
 393   bool was_discarding_output = pfile->state.discarding_output;
 394   int skip = 1;
 395
 396   if (was_discarding_output)
 397     pfile->state.prevent_expansion = 0;
 398
 399   if (was_parsing_args)
 400     {
 401       if (CPP_OPTION (pfile, pedantic))
 402         cpp_error (pfile, CPP_DL_PEDWARN,
 403              "embedding a directive within macro arguments is not portable");
 404       pfile->state.parsing_args = 0;
 405       pfile->state.prevent_expansion = 0;
 406     }
 407   start_directive (pfile);
 408   dname = _cpp_lex_token (pfile);
 409
 410   if (dname->type == CPP_NAME)
 411     {
 412       if (dname->val.node.node->is_directive)
 413         dir = &dtable[dname->val.node.node->directive_index];
 414     }
 415   /* We do not recognize the # followed by a number extension in
 416      assembler code.  */
 417   else if (dname->type == CPP_NUMBER && CPP_OPTION (pfile, lang) != CLK_ASM)
 418     {
 419       dir = &linemarker_dir;
 420       if (CPP_PEDANTIC (pfile) && ! CPP_OPTION (pfile, preprocessed)
 421           && ! pfile->state.skipping)
 422         cpp_error (pfile, CPP_DL_PEDWARN,
 423                    "style of line directive is a GCC extension");
 424     }
 425
 426   if (dir)
 427     {
 428       /* If we have a directive that is not an opening conditional,
 429          invalidate any control macro.  */
 430       if (! (dir->flags & IF_COND))
 431         pfile->mi_valid = false;
 432
 433       /* Kluge alert.  In order to be sure that code like this
 434
 435          #define HASH #
 436          HASH define foo bar
 437
 438          does not cause '#define foo bar' to get executed when
 439          compiled with -save-temps, we recognize directives in
 440          -fpreprocessed mode only if the # is in column 1.  macro.c
 441          puts a space in front of any '#' at the start of a macro.
 442
 443          We exclude the -fdirectives-only case because macro expansion
 444          has not been performed yet, and block comments can cause spaces
 445          to preceed the directive.  */
 446       if (CPP_OPTION (pfile, preprocessed)
 447           && !CPP_OPTION (pfile, directives_only)
 448           && (indented || !(dir->flags & IN_I)))
 449         {
 450           skip = 0;
 451           dir = 0;
 452         }
 453       else
 454         {
 455           /* In failed conditional groups, all non-conditional
 456              directives are ignored.  Before doing that, whether
 457              skipping or not, we should lex angle-bracketed headers
 458              correctly, and maybe output some diagnostics.  */
 459           pfile->state.angled_headers = dir->flags & INCL;
 460           pfile->state.directive_wants_padding = dir->flags & INCL;
 461           if (! CPP_OPTION (pfile, preprocessed))
 462             directive_diagnostics (pfile, dir, indented);
 463           if (pfile->state.skipping && !(dir->flags & COND))
 464             dir = 0;
 465         }
 466     }
 467   else if (dname->type == CPP_EOF)
 468     ;   /* CPP_EOF is the "null directive".  */
 469   else
 470     {
 471       /* An unknown directive.  Don't complain about it in assembly
 472          source: we don't know where the comments are, and # may
 473          introduce assembler pseudo-ops.  Don't complain about invalid
 474          directives in skipped conditional groups (6.10 p4).  */
 475       if (CPP_OPTION (pfile, lang) == CLK_ASM)
 476         skip = 0;
 477       else if (!pfile->state.skipping)
 478         cpp_error (pfile, CPP_DL_ERROR, "invalid preprocessing directive #%s",
 479                    cpp_token_as_text (pfile, dname));
 480     }
 481
 482   pfile->directive = dir;
 483   if (CPP_OPTION (pfile, traditional))
 484     prepare_directive_trad (pfile);
 485
 486   if (dir)
 487     pfile->directive->handler (pfile);
 488   else if (skip == 0)
 489     _cpp_backup_tokens (pfile, 1);
 490
 491   end_directive (pfile, skip);
 492   if (was_parsing_args && !pfile->state.in_deferred_pragma)
 493     {
 494       /* Restore state when within macro args.  */
 495       pfile->state.parsing_args = 2;
 496       pfile->state.prevent_expansion = 1;
 497     }
 498   if (was_discarding_output)
 499     pfile->state.prevent_expansion = 1;
 500   return skip;
 501 }
 502
 503 /* Directive handler wrapper used by the command line option
 504    processor.  BUF is \n terminated.  */
 505 static void
 506 run_directive (cpp_reader *pfile, int dir_no, const char *buf, size_t count)
 507 {
 508   cpp_push_buffer (pfile, (const uchar *) buf, count,
 509                    /* from_stage3 */ true);
 510   start_directive (pfile);
 511
 512   /* This is a short-term fix to prevent a leading '#' being
 513      interpreted as a directive.  */
 514   _cpp_clean_line (pfile);
 515
 516   pfile->directive = &dtable[dir_no];
 517   if (CPP_OPTION (pfile, traditional))
 518     prepare_directive_trad (pfile);
 519   pfile->directive->handler (pfile);
 520   end_directive (pfile, 1);
 521   _cpp_pop_buffer (pfile);
 522 }
 523
 524 /* Checks for validity the macro name in #define, #undef, #ifdef and
 525    #ifndef directives.  IS_DEF_OR_UNDEF is true if this call is
 526    processing a #define or #undefine directive, and false
 527    otherwise.  */
 528 static cpp_hashnode *
 529 lex_macro_node (cpp_reader *pfile, bool is_def_or_undef)
 530 {
 531   const cpp_token *token = _cpp_lex_token (pfile);
 532
 533   /* The token immediately after #define must be an identifier.  That
 534      identifier may not be "defined", per C99 6.10.8p4.
 535      In C++, it may not be any of the "named operators" either,
 536      per C++98 [lex.digraph], [lex.key].
 537      Finally, the identifier may not have been poisoned.  (In that case
 538      the lexer has issued the error message for us.)  */
 539
 540   if (token->type == CPP_NAME)
 541     {
 542       cpp_hashnode *node = token->val.node.node;
 543
 544       if (is_def_or_undef && node == pfile->spec_nodes.n_defined)
 545         cpp_error (pfile, CPP_DL_ERROR,
 546                    "\"defined\" cannot be used as a macro name");
 547       else if (! (node->flags & NODE_POISONED))
 548         return node;
 549     }
 550   else if (token->flags & NAMED_OP)
 551     cpp_error (pfile, CPP_DL_ERROR,
 552        "\"%s\" cannot be used as a macro name as it is an operator in C++",
 553                NODE_NAME (token->val.node.node));
 554   else if (token->type == CPP_EOF)
 555     cpp_error (pfile, CPP_DL_ERROR, "no macro name given in #%s directive",
 556                pfile->directive->name);
 557   else
 558     cpp_error (pfile, CPP_DL_ERROR, "macro names must be identifiers");
 559
 560   return NULL;
 561 }
 562
 563 /* Process a #define directive.  Most work is done in macro.c.  */
 564 static void
 565 do_define (cpp_reader *pfile)
 566 {
 567   cpp_hashnode *node = lex_macro_node (pfile, true);
 568
 569   if (node)
 570     {
 571       /* If we have been requested to expand comments into macros,
 572          then re-enable saving of comments.  */
 573       pfile->state.save_comments =
 574         ! CPP_OPTION (pfile, discard_comments_in_macro_exp);
 575
 576       if (pfile->cb.before_define)
 577         pfile->cb.before_define (pfile);
 578
 579       if (_cpp_create_definition (pfile, node))
 580         if (pfile->cb.define)
 581           pfile->cb.define (pfile, pfile->directive_line, node);
 582
 583       node->flags &= ~NODE_USED;
 584     }
 585 }
 586
 587 /* Handle #undef.  Mark the identifier NT_VOID in the hash table.  */
 588 static void
 589 do_undef (cpp_reader *pfile)
 590 {
 591   cpp_hashnode *node = lex_macro_node (pfile, true);
 592
 593   if (node)
 594     {
 595       if (pfile->cb.before_define)
 596         pfile->cb.before_define (pfile);
 597
 598       if (pfile->cb.undef)
 599         pfile->cb.undef (pfile, pfile->directive_line, node);
 600
 601       /* 6.10.3.5 paragraph 2: [#undef] is ignored if the specified
 602          identifier is not currently defined as a macro name.  */
 603       if (node->type == NT_MACRO)
 604         {
 605           if (node->flags & NODE_WARN)
 606             cpp_error (pfile, CPP_DL_WARNING,
 607                        "undefining \"%s\"", NODE_NAME (node));
 608
 609           if (CPP_OPTION (pfile, warn_unused_macros))
 610             _cpp_warn_if_unused_macro (pfile, node, NULL);
 611
 612           _cpp_free_definition (node);
 613         }
 614     }
 615
 616   check_eol (pfile, false);
 617 }
 618
 619 /* Undefine a single macro/assertion/whatever.  */
 620
 621 static int
 622 undefine_macros (cpp_reader *pfile ATTRIBUTE_UNUSED, cpp_hashnode *h,
 623                  void *data_p ATTRIBUTE_UNUSED)
 624 {
 625   /* Body of _cpp_free_definition inlined here for speed.
 626      Macros and assertions no longer have anything to free.  */
 627   h->type = NT_VOID;
 628   h->flags &= ~(NODE_POISONED|NODE_BUILTIN|NODE_DISABLED|NODE_USED);
 629   return 1;
 630 }
 631
 632 /* Undefine all macros and assertions.  */
 633
 634 void
 635 cpp_undef_all (cpp_reader *pfile)
 636 {
 637   cpp_forall_identifiers (pfile, undefine_macros, NULL);
 638 }
 639
 640
 641 /* Helper routine used by parse_include.  Reinterpret the current line
 642    as an h-char-sequence (< ... >); we are looking at the first token
 643    after the <.  Returns a malloced filename.  */
 644 static char *
 645 glue_header_name (cpp_reader *pfile)
 646 {
 647   const cpp_token *token;
 648   char *buffer;
 649   size_t len, total_len = 0, capacity = 1024;
 650
 651   /* To avoid lexed tokens overwriting our glued name, we can only
 652      allocate from the string pool once we've lexed everything.  */
 653   buffer = XNEWVEC (char, capacity);
 654   for (;;)
 655     {
 656       token = get_token_no_padding (pfile);
 657
 658       if (token->type == CPP_GREATER)
 659         break;
 660       if (token->type == CPP_EOF)
 661         {
 662           cpp_error (pfile, CPP_DL_ERROR, "missing terminating > character");
 663           break;
 664         }
 665
 666       len = cpp_token_len (token) + 2; /* Leading space, terminating \0.  */
 667       if (total_len + len > capacity)
 668         {
 669           capacity = (capacity + len) * 2;
 670           buffer = XRESIZEVEC (char, buffer, capacity);
 671         }
 672
 673       if (token->flags & PREV_WHITE)
 674         buffer[total_len++] = ' ';
 675
 676       total_len = (cpp_spell_token (pfile, token, (uchar *) &buffer[total_len],
 677                                     true)
 678                    - (uchar *) buffer);
 679     }
 680
 681   buffer[total_len] = '\0';
 682   return buffer;
 683 }
 684
 685 /* Returns the file name of #include, #include_next, #import and
 686    #pragma dependency.  The string is malloced and the caller should
 687    free it.  Returns NULL on error.  LOCATION is the source location
 688    of the file name.  */
 689
 690 static const char *
 691 parse_include (cpp_reader *pfile, int *pangle_brackets,
 692                const cpp_token ***buf, source_location *location)
 693 {
 694   char *fname;
 695   const cpp_token *header;
 696
 697   /* Allow macro expansion.  */
 698   header = get_token_no_padding (pfile);
 699   *location = header->src_loc;
 700   if (header->type == CPP_STRING || header->type == CPP_HEADER_NAME)
 701     {
 702       fname = XNEWVEC (char, header->val.str.len - 1);
 703       memcpy (fname, header->val.str.text + 1, header->val.str.len - 2);
 704       fname[header->val.str.len - 2] = '\0';
 705       *pangle_brackets = header->type == CPP_HEADER_NAME;
 706     }
 707   else if (header->type == CPP_LESS)
 708     {
 709       fname = glue_header_name (pfile);
 710       *pangle_brackets = 1;
 711     }
 712   else
 713     {
 714       const unsigned char *dir;
 715
 716       if (pfile->directive == &dtable[T_PRAGMA])
 717         dir = UC"pragma dependency";
 718       else
 719         dir = pfile->directive->name;
 720       cpp_error (pfile, CPP_DL_ERROR, "#%s expects \"FILENAME\" or <FILENAME>",
 721                  dir);
 722
 723       return NULL;
 724     }
 725
 726   if (pfile->directive == &dtable[T_PRAGMA])
 727     {
 728       /* This pragma allows extra tokens after the file name.  */
 729     }
 730   else if (buf == NULL || CPP_OPTION (pfile, discard_comments))
 731     check_eol (pfile, true);
 732   else
 733     {
 734       /* If we are not discarding comments, then gather them while
 735          doing the eol check.  */
 736       *buf = check_eol_return_comments (pfile);
 737     }
 738
 739   return fname;
 740 }
 741
 742 /* Handle #include, #include_next and #import.  */
 743 static void
 744 do_include_common (cpp_reader *pfile, enum include_type type)
 745 {
 746   const char *fname;
 747   int angle_brackets;
 748   const cpp_token **buf = NULL;
 749   source_location location;
 750
 751   /* Re-enable saving of comments if requested, so that the include
 752      callback can dump comments which follow #include.  */
 753   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 754
 755   fname = parse_include (pfile, &angle_brackets, &buf, &location);
 756   if (!fname)
 757     {
 758       if (buf)
 759         XDELETEVEC (buf);
 760       return;
 761     }
 762
 763   if (!*fname)
 764   {
 765     cpp_error_with_line (pfile, CPP_DL_ERROR, location, 0,
 766                          "empty filename in #%s",
 767                          pfile->directive->name);
 768     XDELETEVEC (fname);
 769     if (buf)
 770       XDELETEVEC (buf);
 771     return;
 772   }
 773
 774   /* Prevent #include recursion.  */
 775   if (pfile->line_table->depth >= CPP_STACK_MAX)
 776     cpp_error (pfile, CPP_DL_ERROR, "#include nested too deeply");
 777   else
 778     {
 779       /* Get out of macro context, if we are.  */
 780       skip_rest_of_line (pfile);
 781
 782       if (pfile->cb.include)
 783         pfile->cb.include (pfile, pfile->directive_line,
 784                            pfile->directive->name, fname, angle_brackets,
 785                            buf);
 786
 787       _cpp_stack_include (pfile, fname, angle_brackets, type);
 788     }
 789
 790   XDELETEVEC (fname);
 791   if (buf)
 792     XDELETEVEC (buf);
 793 }
 794
 795 static void
 796 do_include (cpp_reader *pfile)
 797 {
 798   do_include_common (pfile, IT_INCLUDE);
 799 }
 800
 801 static void
 802 do_import (cpp_reader *pfile)
 803 {
 804   do_include_common (pfile, IT_IMPORT);
 805 }
 806
 807 static void
 808 do_include_next (cpp_reader *pfile)
 809 {
 810   enum include_type type = IT_INCLUDE_NEXT;
 811
 812   /* If this is the primary source file, warn and use the normal
 813      search logic.  */
 814   if (cpp_in_primary_file (pfile))
 815     {
 816       cpp_error (pfile, CPP_DL_WARNING,
 817                  "#include_next in primary source file");
 818       type = IT_INCLUDE;
 819     }
 820   do_include_common (pfile, type);
 821 }
 822
 823 /* Subroutine of do_linemarker.  Read possible flags after file name.
 824    LAST is the last flag seen; 0 if this is the first flag. Return the
 825    flag if it is valid, 0 at the end of the directive. Otherwise
 826    complain.  */
 827 static unsigned int
 828 read_flag (cpp_reader *pfile, unsigned int last)
 829 {
 830   const cpp_token *token = _cpp_lex_token (pfile);
 831
 832   if (token->type == CPP_NUMBER && token->val.str.len == 1)
 833     {
 834       unsigned int flag = token->val.str.text[0] - '0';
 835
 836       if (flag > last && flag <= 4
 837           && (flag != 4 || last == 3)
 838           && (flag != 2 || last == 0))
 839         return flag;
 840     }
 841
 842   if (token->type != CPP_EOF)
 843     cpp_error (pfile, CPP_DL_ERROR, "invalid flag \"%s\" in line directive",
 844                cpp_token_as_text (pfile, token));
 845   return 0;
 846 }
 847
 848 /* Subroutine of do_line and do_linemarker.  Convert a number in STR,
 849    of length LEN, to binary; store it in NUMP, and return false if the
 850    number was well-formed, true if not. WRAPPED is set to true if the
 851    number did not fit into 'unsigned long'.  */
 852 static bool
 853 strtolinenum (const uchar *str, size_t len, linenum_type *nump, bool *wrapped)
 854 {
 855   linenum_type reg = 0;
 856   linenum_type reg_prev = 0;
 857
 858   uchar c;
 859   *wrapped = false;
 860   while (len--)
 861     {
 862       c = *str++;
 863       if (!ISDIGIT (c))
 864         return true;
 865       reg *= 10;
 866       reg += c - '0';
 867       if (reg < reg_prev)
 868         *wrapped = true;
 869       reg_prev = reg;
 870     }
 871   *nump = reg;
 872   return false;
 873 }
 874
 875 /* Interpret #line command.
 876    Note that the filename string (if any) is a true string constant
 877    (escapes are interpreted), unlike in #line.  */
 878 static void
 879 do_line (cpp_reader *pfile)
 880 {
 881   const struct line_maps *line_table = pfile->line_table;
 882   const struct line_map *map = &line_table->maps[line_table->used - 1];
 883
 884   /* skip_rest_of_line() may cause line table to be realloc()ed so note down
 885      sysp right now.  */
 886
 887   unsigned char map_sysp = map->sysp;
 888   const cpp_token *token;
 889   const char *new_file = map->to_file;
 890   linenum_type new_lineno;
 891
 892   /* C99 raised the minimum limit on #line numbers.  */
 893   linenum_type cap = CPP_OPTION (pfile, c99) ? 2147483647 : 32767;
 894   bool wrapped;
 895
 896   /* #line commands expand macros.  */
 897   token = cpp_get_token (pfile);
 898   if (token->type != CPP_NUMBER
 899       || strtolinenum (token->val.str.text, token->val.str.len,
 900                        &new_lineno, &wrapped))
 901     {
 902       if (token->type == CPP_EOF)
 903         cpp_error (pfile, CPP_DL_ERROR, "unexpected end of file after #line");
 904       else
 905         cpp_error (pfile, CPP_DL_ERROR,
 906                    "\"%s\" after #line is not a positive integer",
 907                    cpp_token_as_text (pfile, token));
 908       return;
 909     }
 910
 911   if (CPP_PEDANTIC (pfile) && (new_lineno == 0 || new_lineno > cap || wrapped))
 912     cpp_error (pfile, CPP_DL_PEDWARN, "line number out of range");
 913   else if (wrapped)
 914     cpp_error (pfile, CPP_DL_WARNING, "line number out of range");
 915
 916   token = cpp_get_token (pfile);
 917   if (token->type == CPP_STRING)
 918     {
 919       cpp_string s = { 0, 0 };
 920       if (cpp_interpret_string_notranslate (pfile, &token->val.str, 1,
 921                                             &s, false))
 922         new_file = (const char *)s.text;
 923       check_eol (pfile, true);
 924     }
 925   else if (token->type != CPP_EOF)
 926     {
 927       cpp_error (pfile, CPP_DL_ERROR, "\"%s\" is not a valid filename",
 928                  cpp_token_as_text (pfile, token));
 929       return;
 930     }
 931
 932   skip_rest_of_line (pfile);
 933   _cpp_do_file_change (pfile, LC_RENAME_VERBATIM, new_file, new_lineno,
 934                        map_sysp);
 935 }
 936
 937 /* Interpret the # 44 "file" [flags] notation, which has slightly
 938    different syntax and semantics from #line:  Flags are allowed,
 939    and we never complain about the line number being too big.  */
 940 static void
 941 do_linemarker (cpp_reader *pfile)
 942 {
 943   const struct line_maps *line_table = pfile->line_table;
 944   const struct line_map *map = &line_table->maps[line_table->used - 1];
 945   const cpp_token *token;
 946   const char *new_file = map->to_file;
 947   linenum_type new_lineno;
 948   unsigned int new_sysp = map->sysp;
 949   enum lc_reason reason = LC_RENAME_VERBATIM;
 950   int flag;
 951   bool wrapped;
 952
 953   /* Back up so we can get the number again.  Putting this in
 954      _cpp_handle_directive risks two calls to _cpp_backup_tokens in
 955      some circumstances, which can segfault.  */
 956   _cpp_backup_tokens (pfile, 1);
 957
 958   /* #line commands expand macros.  */
 959   token = cpp_get_token (pfile);
 960   if (token->type != CPP_NUMBER
 961       || strtolinenum (token->val.str.text, token->val.str.len,
 962                        &new_lineno, &wrapped))
 963     {
 964       /* Unlike #line, there does not seem to be a way to get an EOF
 965          here.  So, it should be safe to always spell the token.  */
 966       cpp_error (pfile, CPP_DL_ERROR,
 967                  "\"%s\" after # is not a positive integer",
 968                  cpp_token_as_text (pfile, token));
 969       return;
 970     }
 971
 972   token = cpp_get_token (pfile);
 973   if (token->type == CPP_STRING)
 974     {
 975       cpp_string s = { 0, 0 };
 976       if (cpp_interpret_string_notranslate (pfile, &token->val.str,
 977                                             1, &s, false))
 978         new_file = (const char *)s.text;
 979
 980       new_sysp = 0;
 981       flag = read_flag (pfile, 0);
 982       if (flag == 1)
 983         {
 984           reason = LC_ENTER;
 985           /* Fake an include for cpp_included ().  */
 986           _cpp_fake_include (pfile, new_file);
 987           flag = read_flag (pfile, flag);
 988         }
 989       else if (flag == 2)
 990         {
 991           reason = LC_LEAVE;
 992           flag = read_flag (pfile, flag);
 993         }
 994       if (flag == 3)
 995         {
 996           new_sysp = 1;
 997           flag = read_flag (pfile, flag);
 998           if (flag == 4)
 999             new_sysp = 2;
1000         }
1001       pfile->buffer->sysp = new_sysp;
1002
1003       check_eol (pfile, false);
1004     }
1005   else if (token->type != CPP_EOF)
1006     {
1007       cpp_error (pfile, CPP_DL_ERROR, "\"%s\" is not a valid filename",
1008                  cpp_token_as_text (pfile, token));
1009       return;
1010     }
1011
1012   skip_rest_of_line (pfile);
1013
1014   /* Compensate for the increment in linemap_add that occurs in
1015      _cpp_do_file_change.  We're currently at the start of the line
1016      *following* the #line directive.  A separate source_location for this
1017      location makes no sense (until we do the LC_LEAVE), and
1018      complicates LAST_SOURCE_LINE_LOCATION.  */
1019   pfile->line_table->highest_location--;
1020
1021   _cpp_do_file_change (pfile, reason, new_file, new_lineno, new_sysp);
1022 }
1023
1024 /* Arrange the file_change callback.  pfile->line has changed to
1025    FILE_LINE of TO_FILE, for reason REASON.  SYSP is 1 for a system
1026    header, 2 for a system header that needs to be extern "C" protected,
1027    and zero otherwise.  */
1028 void
1029 _cpp_do_file_change (cpp_reader *pfile, enum lc_reason reason,
1030                      const char *to_file, linenum_type file_line,
1031                      unsigned int sysp)
1032 {
1033   const struct line_map *map = linemap_add (pfile->line_table, reason, sysp,
1034                                             to_file, file_line);
1035   if (map != NULL)
1036     linemap_line_start (pfile->line_table, map->to_line, 127);
1037
1038   if (pfile->cb.file_change)
1039     pfile->cb.file_change (pfile, map);
1040 }
1041
1042 /* Report a warning or error detected by the program we are
1043    processing.  Use the directive's tokens in the error message.  */
1044 static void
1045 do_diagnostic (cpp_reader *pfile, int code, int print_dir)
1046 {
1047   const unsigned char *dir_name;
1048   unsigned char *line;
1049   source_location src_loc = pfile->cur_token[-1].src_loc;
1050
1051   if (print_dir)
1052     dir_name = pfile->directive->name;
1053   else
1054     dir_name = NULL;
1055   pfile->state.prevent_expansion++;
1056   line = cpp_output_line_to_string (pfile, dir_name);
1057   pfile->state.prevent_expansion--;
1058
1059   cpp_error_with_line (pfile, code, src_loc, 0, "%s", line);
1060   free (line);
1061 }
1062
1063 static void
1064 do_error (cpp_reader *pfile)
1065 {
1066   do_diagnostic (pfile, CPP_DL_ERROR, 1);
1067 }
1068
1069 static void
1070 do_warning (cpp_reader *pfile)
1071 {
1072   /* We want #warning diagnostics to be emitted in system headers too.  */
1073   do_diagnostic (pfile, CPP_DL_WARNING_SYSHDR, 1);
1074 }
1075
1076 /* Report program identification.  */
1077 static void
1078 do_ident (cpp_reader *pfile)
1079 {
1080   const cpp_token *str = cpp_get_token (pfile);
1081
1082   if (str->type != CPP_STRING)
1083     cpp_error (pfile, CPP_DL_ERROR, "invalid #%s directive",
1084                pfile->directive->name);
1085   else if (pfile->cb.ident)
1086     pfile->cb.ident (pfile, pfile->directive_line, &str->val.str);
1087
1088   check_eol (pfile, false);
1089 }
1090
1091 /* Lookup a PRAGMA name in a singly-linked CHAIN.  Returns the
1092    matching entry, or NULL if none is found.  The returned entry could
1093    be the start of a namespace chain, or a pragma.  */
1094 static struct pragma_entry *
1095 lookup_pragma_entry (struct pragma_entry *chain, const cpp_hashnode *pragma)
1096 {
1097   while (chain && chain->pragma != pragma)
1098     chain = chain->next;
1099
1100   return chain;
1101 }
1102
1103 /* Create and insert a blank pragma entry at the beginning of a
1104    singly-linked CHAIN.  */
1105 static struct pragma_entry *
1106 new_pragma_entry (cpp_reader *pfile, struct pragma_entry **chain)
1107 {
1108   struct pragma_entry *new_entry;
1109
1110   new_entry = (struct pragma_entry *)
1111     _cpp_aligned_alloc (pfile, sizeof (struct pragma_entry));
1112
1113   memset (new_entry, 0, sizeof (struct pragma_entry));
1114   new_entry->next = *chain;
1115
1116   *chain = new_entry;
1117   return new_entry;
1118 }
1119
1120 /* Register a pragma NAME in namespace SPACE.  If SPACE is null, it
1121    goes in the global namespace.  */
1122 static struct pragma_entry *
1123 register_pragma_1 (cpp_reader *pfile, const char *space, const char *name,
1124                    bool allow_name_expansion)
1125 {
1126   struct pragma_entry **chain = &pfile->pragmas;
1127   struct pragma_entry *entry;
1128   const cpp_hashnode *node;
1129
1130   if (space)
1131     {
1132       node = cpp_lookup (pfile, UC space, strlen (space));
1133       entry = lookup_pragma_entry (*chain, node);
1134       if (!entry)
1135         {
1136           entry = new_pragma_entry (pfile, chain);
1137           entry->pragma = node;
1138           entry->is_nspace = true;
1139           entry->allow_expansion = allow_name_expansion;
1140         }
1141       else if (!entry->is_nspace)
1142         goto clash;
1143       else if (entry->allow_expansion != allow_name_expansion)
1144         {
1145           cpp_error (pfile, CPP_DL_ICE,
1146                      "registering pragmas in namespace \"%s\" with mismatched "
1147                      "name expansion", space);
1148           return NULL;
1149         }
1150       chain = &entry->u.space;
1151     }
1152   else if (allow_name_expansion)
1153     {
1154       cpp_error (pfile, CPP_DL_ICE,
1155                  "registering pragma \"%s\" with name expansion "
1156                  "and no namespace", name);
1157       return NULL;
1158     }
1159
1160   /* Check for duplicates.  */
1161   node = cpp_lookup (pfile, UC name, strlen (name));
1162   entry = lookup_pragma_entry (*chain, node);
1163   if (entry == NULL)
1164     {
1165       entry = new_pragma_entry (pfile, chain);
1166       entry->pragma = node;
1167       return entry;
1168     }
1169
1170   if (entry->is_nspace)
1171     clash:
1172     cpp_error (pfile, CPP_DL_ICE,
1173                "registering \"%s\" as both a pragma and a pragma namespace",
1174                NODE_NAME (node));
1175   else if (space)
1176     cpp_error (pfile, CPP_DL_ICE, "#pragma %s %s is already registered",
1177                space, name);
1178   else
1179     cpp_error (pfile, CPP_DL_ICE, "#pragma %s is already registered", name);
1180
1181   return NULL;
1182 }
1183
1184 /* Register a cpplib internal pragma SPACE NAME with HANDLER.  */
1185 static void
1186 register_pragma_internal (cpp_reader *pfile, const char *space,
1187                           const char *name, pragma_cb handler)
1188 {
1189   struct pragma_entry *entry;
1190
1191   entry = register_pragma_1 (pfile, space, name, false);
1192   entry->is_internal = true;
1193   entry->u.handler = handler;
1194 }
1195
1196 /* Register a pragma NAME in namespace SPACE.  If SPACE is null, it
1197    goes in the global namespace.  HANDLER is the handler it will call,
1198    which must be non-NULL.  If ALLOW_EXPANSION is set, allow macro
1199    expansion while parsing pragma NAME.  This function is exported
1200    from libcpp. */
1201 void
1202 cpp_register_pragma (cpp_reader *pfile, const char *space, const char *name,
1203                      pragma_cb handler, bool allow_expansion)
1204 {
1205   struct pragma_entry *entry;
1206
1207   if (!handler)
1208     {
1209       cpp_error (pfile, CPP_DL_ICE, "registering pragma with NULL handler");
1210       return;
1211     }
1212
1213   entry = register_pragma_1 (pfile, space, name, false);
1214   if (entry)
1215     {
1216       entry->allow_expansion = allow_expansion;
1217       entry->u.handler = handler;
1218     }
1219 }
1220
1221 /* Similarly, but create mark the pragma for deferred processing.
1222    When found, a CPP_PRAGMA token will be insertted into the stream
1223    with IDENT in the token->u.pragma slot.  */
1224 void
1225 cpp_register_deferred_pragma (cpp_reader *pfile, const char *space,
1226                               const char *name, unsigned int ident,
1227                               bool allow_expansion, bool allow_name_expansion)
1228 {
1229   struct pragma_entry *entry;
1230
1231   entry = register_pragma_1 (pfile, space, name, allow_name_expansion);
1232   if (entry)
1233     {
1234       entry->is_deferred = true;
1235       entry->allow_expansion = allow_expansion;
1236       entry->u.ident = ident;
1237     }
1238 }
1239
1240 /* Register the pragmas the preprocessor itself handles.  */
1241 void
1242 _cpp_init_internal_pragmas (cpp_reader *pfile)
1243 {
1244   /* Pragmas in the global namespace.  */
1245   register_pragma_internal (pfile, 0, "once", do_pragma_once);
1246
1247   /* New GCC-specific pragmas should be put in the GCC namespace.  */
1248   register_pragma_internal (pfile, "GCC", "poison", do_pragma_poison);
1249   register_pragma_internal (pfile, "GCC", "system_header",
1250                             do_pragma_system_header);
1251   register_pragma_internal (pfile, "GCC", "dependency", do_pragma_dependency);
1252 }
1253
1254 /* Return the number of registered pragmas in PE.  */
1255
1256 static int
1257 count_registered_pragmas (struct pragma_entry *pe)
1258 {
1259   int ct = 0;
1260   for (; pe != NULL; pe = pe->next)
1261     {
1262       if (pe->is_nspace)
1263         ct += count_registered_pragmas (pe->u.space);
1264       ct++;
1265     }
1266   return ct;
1267 }
1268
1269 /* Save into SD the names of the registered pragmas referenced by PE,
1270    and return a pointer to the next free space in SD.  */
1271
1272 static char **
1273 save_registered_pragmas (struct pragma_entry *pe, char **sd)
1274 {
1275   for (; pe != NULL; pe = pe->next)
1276     {
1277       if (pe->is_nspace)
1278         sd = save_registered_pragmas (pe->u.space, sd);
1279       *sd++ = (char *) xmemdup (HT_STR (&pe->pragma->ident),
1280                                 HT_LEN (&pe->pragma->ident),
1281                                 HT_LEN (&pe->pragma->ident) + 1);
1282     }
1283   return sd;
1284 }
1285
1286 /* Return a newly-allocated array which saves the names of the
1287    registered pragmas.  */
1288
1289 char **
1290 _cpp_save_pragma_names (cpp_reader *pfile)
1291 {
1292   int ct = count_registered_pragmas (pfile->pragmas);
1293   char **result = XNEWVEC (char *, ct);
1294   (void) save_registered_pragmas (pfile->pragmas, result);
1295   return result;
1296 }
1297
1298 /* Restore from SD the names of the registered pragmas referenced by PE,
1299    and return a pointer to the next unused name in SD.  */
1300
1301 static char **
1302 restore_registered_pragmas (cpp_reader *pfile, struct pragma_entry *pe,
1303                             char **sd)
1304 {
1305   for (; pe != NULL; pe = pe->next)
1306     {
1307       if (pe->is_nspace)
1308         sd = restore_registered_pragmas (pfile, pe->u.space, sd);
1309       pe->pragma = cpp_lookup (pfile, UC *sd, strlen (*sd));
1310       free (*sd);
1311       sd++;
1312     }
1313   return sd;
1314 }
1315
1316 /* Restore the names of the registered pragmas from SAVED.  */
1317
1318 void
1319 _cpp_restore_pragma_names (cpp_reader *pfile, char **saved)
1320 {
1321   (void) restore_registered_pragmas (pfile, pfile->pragmas, saved);
1322   free (saved);
1323 }
1324
1325 /* Pragmata handling.  We handle some, and pass the rest on to the
1326    front end.  C99 defines three pragmas and says that no macro
1327    expansion is to be performed on them; whether or not macro
1328    expansion happens for other pragmas is implementation defined.
1329    This implementation allows for a mix of both, since GCC did not
1330    traditionally macro expand its (few) pragmas, whereas OpenMP
1331    specifies that macro expansion should happen.  */
1332 static void
1333 do_pragma (cpp_reader *pfile)
1334 {
1335   const struct pragma_entry *p = NULL;
1336   const cpp_token *token, *pragma_token = pfile->cur_token;
1337   cpp_token ns_token;
1338   unsigned int count = 1;
1339
1340   pfile->state.prevent_expansion++;
1341
1342   token = cpp_get_token (pfile);
1343   ns_token = *token;
1344   if (token->type == CPP_NAME)
1345     {
1346       p = lookup_pragma_entry (pfile->pragmas, token->val.node.node);
1347       if (p && p->is_nspace)
1348         {
1349           bool allow_name_expansion = p->allow_expansion;
1350           if (allow_name_expansion)
1351             pfile->state.prevent_expansion--;
1352           token = cpp_get_token (pfile);
1353           if (token->type == CPP_NAME)
1354             p = lookup_pragma_entry (p->u.space, token->val.node.node);
1355           else
1356             p = NULL;
1357           if (allow_name_expansion)
1358             pfile->state.prevent_expansion++;
1359           count = 2;
1360         }
1361     }
1362
1363   if (p)
1364     {
1365       if (p->is_deferred)
1366         {
1367           pfile->directive_result.src_loc = pragma_token->src_loc;
1368           pfile->directive_result.type = CPP_PRAGMA;
1369           pfile->directive_result.flags = pragma_token->flags;
1370           pfile->directive_result.val.pragma = p->u.ident;
1371           pfile->state.in_deferred_pragma = true;
1372           pfile->state.pragma_allow_expansion = p->allow_expansion;
1373           if (!p->allow_expansion)
1374             pfile->state.prevent_expansion++;
1375         }
1376       else
1377         {
1378           /* Since the handler below doesn't get the line number, that
1379              it might need for diagnostics, make sure it has the right
1380              numbers in place.  */
1381           if (pfile->cb.line_change)
1382             (*pfile->cb.line_change) (pfile, pragma_token, false);
1383           if (p->allow_expansion)
1384             pfile->state.prevent_expansion--;
1385           (*p->u.handler) (pfile);
1386           if (p->allow_expansion)
1387             pfile->state.prevent_expansion++;
1388         }
1389     }
1390   else if (pfile->cb.def_pragma)
1391     {
1392       if (count == 1 || pfile->context->prev == NULL)
1393         _cpp_backup_tokens (pfile, count);
1394       else
1395         {
1396           /* Invalid name comes from macro expansion, _cpp_backup_tokens
1397              won't allow backing 2 tokens.  */
1398           /* ??? The token buffer is leaked.  Perhaps if def_pragma hook
1399              reads both tokens, we could perhaps free it, but if it doesn't,
1400              we don't know the exact lifespan.  */
1401           cpp_token *toks = XNEWVEC (cpp_token, 2);
1402           toks[0] = ns_token;
1403           toks[0].flags |= NO_EXPAND;
1404           toks[1] = *token;
1405           toks[1].flags |= NO_EXPAND;
1406           _cpp_push_token_context (pfile, NULL, toks, 2);
1407         }
1408       pfile->cb.def_pragma (pfile, pfile->directive_line);
1409     }
1410
1411   pfile->state.prevent_expansion--;
1412 }
1413
1414 /* Handle #pragma once.  */
1415 static void
1416 do_pragma_once (cpp_reader *pfile)
1417 {
1418   if (cpp_in_primary_file (pfile))
1419     cpp_error (pfile, CPP_DL_WARNING, "#pragma once in main file");
1420
1421   check_eol (pfile, false);
1422   _cpp_mark_file_once_only (pfile, pfile->buffer->file);
1423 }
1424
1425 /* Handle #pragma GCC poison, to poison one or more identifiers so
1426    that the lexer produces a hard error for each subsequent usage.  */
1427 static void
1428 do_pragma_poison (cpp_reader *pfile)
1429 {
1430   const cpp_token *tok;
1431   cpp_hashnode *hp;
1432
1433   pfile->state.poisoned_ok = 1;
1434   for (;;)
1435     {
1436       tok = _cpp_lex_token (pfile);
1437       if (tok->type == CPP_EOF)
1438         break;
1439       if (tok->type != CPP_NAME)
1440         {
1441           cpp_error (pfile, CPP_DL_ERROR,
1442                      "invalid #pragma GCC poison directive");
1443           break;
1444         }
1445
1446       hp = tok->val.node.node;
1447       if (hp->flags & NODE_POISONED)
1448         continue;
1449
1450       if (hp->type == NT_MACRO)
1451         cpp_error (pfile, CPP_DL_WARNING, "poisoning existing macro \"%s\"",
1452                    NODE_NAME (hp));
1453       _cpp_free_definition (hp);
1454       hp->flags |= NODE_POISONED | NODE_DIAGNOSTIC;
1455     }
1456   pfile->state.poisoned_ok = 0;
1457 }
1458
1459 /* Mark the current header as a system header.  This will suppress
1460    some categories of warnings (notably those from -pedantic).  It is
1461    intended for use in system libraries that cannot be implemented in
1462    conforming C, but cannot be certain that their headers appear in a
1463    system include directory.  To prevent abuse, it is rejected in the
1464    primary source file.  */
1465 static void
1466 do_pragma_system_header (cpp_reader *pfile)
1467 {
1468   if (cpp_in_primary_file (pfile))
1469     cpp_error (pfile, CPP_DL_WARNING,
1470                "#pragma system_header ignored outside include file");
1471   else
1472     {
1473       check_eol (pfile, false);
1474       skip_rest_of_line (pfile);
1475       cpp_make_system_header (pfile, 1, 0);
1476     }
1477 }
1478
1479 /* Check the modified date of the current include file against a specified
1480    file. Issue a diagnostic, if the specified file is newer. We use this to
1481    determine if a fixed header should be refixed.  */
1482 static void
1483 do_pragma_dependency (cpp_reader *pfile)
1484 {
1485   const char *fname;
1486   int angle_brackets, ordering;
1487   source_location location;
1488
1489   fname = parse_include (pfile, &angle_brackets, NULL, &location);
1490   if (!fname)
1491     return;
1492
1493   ordering = _cpp_compare_file_date (pfile, fname, angle_brackets);
1494   if (ordering < 0)
1495     cpp_error (pfile, CPP_DL_WARNING, "cannot find source file %s", fname);
1496   else if (ordering > 0)
1497     {
1498       cpp_error (pfile, CPP_DL_WARNING,
1499                  "current file is older than %s", fname);
1500       if (cpp_get_token (pfile)->type != CPP_EOF)
1501         {
1502           _cpp_backup_tokens (pfile, 1);
1503           do_diagnostic (pfile, CPP_DL_WARNING, 0);
1504         }
1505     }
1506
1507   free ((void *) fname);
1508 }
1509
1510 /* Get a token but skip padding.  */
1511 static const cpp_token *
1512 get_token_no_padding (cpp_reader *pfile)
1513 {
1514   for (;;)
1515     {
1516       const cpp_token *result = cpp_get_token (pfile);
1517       if (result->type != CPP_PADDING)
1518         return result;
1519     }
1520 }
1521
1522 /* Check syntax is "(string-literal)".  Returns the string on success,
1523    or NULL on failure.  */
1524 static const cpp_token *
1525 get__Pragma_string (cpp_reader *pfile)
1526 {
1527   const cpp_token *string;
1528   const cpp_token *paren;
1529
1530   paren = get_token_no_padding (pfile);
1531   if (paren->type == CPP_EOF)
1532     _cpp_backup_tokens (pfile, 1);
1533   if (paren->type != CPP_OPEN_PAREN)
1534     return NULL;
1535
1536   string = get_token_no_padding (pfile);
1537   if (string->type == CPP_EOF)
1538     _cpp_backup_tokens (pfile, 1);
1539   if (string->type != CPP_STRING && string->type != CPP_WSTRING
1540       && string->type != CPP_STRING32 && string->type != CPP_STRING16)
1541     return NULL;
1542
1543   paren = get_token_no_padding (pfile);
1544   if (paren->type == CPP_EOF)
1545     _cpp_backup_tokens (pfile, 1);
1546   if (paren->type != CPP_CLOSE_PAREN)
1547     return NULL;
1548
1549   return string;
1550 }
1551
1552 /* Destringize IN into a temporary buffer, by removing the first \ of
1553    \" and \\ sequences, and process the result as a #pragma directive.  */
1554 static void
1555 destringize_and_run (cpp_reader *pfile, const cpp_string *in)
1556 {
1557   const unsigned char *src, *limit;
1558   char *dest, *result;
1559   cpp_context *saved_context;
1560   cpp_token *saved_cur_token;
1561   tokenrun *saved_cur_run;
1562   cpp_token *toks;
1563   int count;
1564   const struct directive *save_directive;
1565
1566   dest = result = (char *) alloca (in->len - 1);
1567   src = in->text + 1 + (in->text[0] == 'L');
1568   limit = in->text + in->len - 1;
1569   while (src < limit)
1570     {
1571       /* We know there is a character following the backslash.  */
1572       if (*src == '\\' && (src[1] == '\\' || src[1] == '"'))
1573         src++;
1574       *dest++ = *src++;
1575     }
1576   *dest = '\n';
1577
1578   /* Ugh; an awful kludge.  We are really not set up to be lexing
1579      tokens when in the middle of a macro expansion.  Use a new
1580      context to force cpp_get_token to lex, and so skip_rest_of_line
1581      doesn't go beyond the end of the text.  Also, remember the
1582      current lexing position so we can return to it later.
1583
1584      Something like line-at-a-time lexing should remove the need for
1585      this.  */
1586   saved_context = pfile->context;
1587   saved_cur_token = pfile->cur_token;
1588   saved_cur_run = pfile->cur_run;
1589
1590   pfile->context = XNEW (cpp_context);
1591   pfile->context->macro = 0;
1592   pfile->context->prev = 0;
1593   pfile->context->next = 0;
1594
1595   /* Inline run_directive, since we need to delay the _cpp_pop_buffer
1596      until we've read all of the tokens that we want.  */
1597   cpp_push_buffer (pfile, (const uchar *) result, dest - result,
1598                    /* from_stage3 */ true);
1599   /* ??? Antique Disgusting Hack.  What does this do?  */
1600   if (pfile->buffer->prev)
1601     pfile->buffer->file = pfile->buffer->prev->file;
1602
1603   start_directive (pfile);
1604   _cpp_clean_line (pfile);
1605   save_directive = pfile->directive;
1606   pfile->directive = &dtable[T_PRAGMA];
1607   do_pragma (pfile);
1608   end_directive (pfile, 1);
1609   pfile->directive = save_directive;
1610
1611   /* We always insert at least one token, the directive result.  It'll
1612      either be a CPP_PADDING or a CPP_PRAGMA.  In the later case, we
1613      need to insert *all* of the tokens, including the CPP_PRAGMA_EOL.  */
1614
1615   /* If we're not handling the pragma internally, read all of the tokens from
1616      the string buffer now, while the string buffer is still installed.  */
1617   /* ??? Note that the token buffer allocated here is leaked.  It's not clear
1618      to me what the true lifespan of the tokens are.  It would appear that
1619      the lifespan is the entire parse of the main input stream, in which case
1620      this may not be wrong.  */
1621   if (pfile->directive_result.type == CPP_PRAGMA)
1622     {
1623       int maxcount;
1624
1625       count = 1;
1626       maxcount = 50;
1627       toks = XNEWVEC (cpp_token, maxcount);
1628       toks[0] = pfile->directive_result;
1629
1630       do
1631         {
1632           if (count == maxcount)
1633             {
1634               maxcount = maxcount * 3 / 2;
1635               toks = XRESIZEVEC (cpp_token, toks, maxcount);
1636             }
1637           toks[count] = *cpp_get_token (pfile);
1638           /* Macros have been already expanded by cpp_get_token
1639              if the pragma allowed expansion.  */
1640           toks[count++].flags |= NO_EXPAND;
1641         }
1642       while (toks[count-1].type != CPP_PRAGMA_EOL);
1643     }
1644   else
1645     {
1646       count = 1;
1647       toks = XNEW (cpp_token);
1648       toks[0] = pfile->directive_result;
1649
1650       /* If we handled the entire pragma internally, make sure we get the
1651          line number correct for the next token.  */
1652       if (pfile->cb.line_change)
1653         pfile->cb.line_change (pfile, pfile->cur_token, false);
1654     }
1655
1656   /* Finish inlining run_directive.  */
1657   pfile->buffer->file = NULL;
1658   _cpp_pop_buffer (pfile);
1659
1660   /* Reset the old macro state before ...  */
1661   XDELETE (pfile->context);
1662   pfile->context = saved_context;
1663   pfile->cur_token = saved_cur_token;
1664   pfile->cur_run = saved_cur_run;
1665
1666   /* ... inserting the new tokens we collected.  */
1667   _cpp_push_token_context (pfile, NULL, toks, count);
1668 }
1669
1670 /* Handle the _Pragma operator.  Return 0 on error, 1 if ok.  */
1671 int
1672 _cpp_do__Pragma (cpp_reader *pfile)
1673 {
1674   const cpp_token *string = get__Pragma_string (pfile);
1675   pfile->directive_result.type = CPP_PADDING;
1676
1677   if (string)
1678     {
1679       destringize_and_run (pfile, &string->val.str);
1680       return 1;
1681     }
1682   cpp_error (pfile, CPP_DL_ERROR,
1683              "_Pragma takes a parenthesized string literal");
1684   return 0;
1685 }
1686
1687 /* Handle #ifdef.  */
1688 static void
1689 do_ifdef (cpp_reader *pfile)
1690 {
1691   int skip = 1;
1692
1693   if (! pfile->state.skipping)
1694     {
1695       cpp_hashnode *node = lex_macro_node (pfile, false);
1696
1697       if (node)
1698         {
1699           skip = node->type != NT_MACRO;
1700           _cpp_mark_macro_used (node);
1701           if (!(node->flags & NODE_USED))
1702             {
1703               node->flags |= NODE_USED;
1704               if (node->type == NT_MACRO)
1705                 {
1706                   if (pfile->cb.used_define)
1707                     pfile->cb.used_define (pfile, pfile->directive_line, node);
1708                 }
1709               else
1710                 {
1711                   if (pfile->cb.used_undef)
1712                     pfile->cb.used_undef (pfile, pfile->directive_line, node);
1713                 }
1714             }
1715           check_eol (pfile, false);
1716         }
1717     }
1718
1719   push_conditional (pfile, skip, T_IFDEF, 0);
1720 }
1721
1722 /* Handle #ifndef.  */
1723 static void
1724 do_ifndef (cpp_reader *pfile)
1725 {
1726   int skip = 1;
1727   cpp_hashnode *node = 0;
1728
1729   if (! pfile->state.skipping)
1730     {
1731       node = lex_macro_node (pfile, false);
1732
1733       if (node)
1734         {
1735           skip = node->type == NT_MACRO;
1736           _cpp_mark_macro_used (node);
1737           if (!(node->flags & NODE_USED))
1738             {
1739               node->flags |= NODE_USED;
1740               if (node->type == NT_MACRO)
1741                 {
1742                   if (pfile->cb.used_define)
1743                     pfile->cb.used_define (pfile, pfile->directive_line, node);
1744                 }
1745               else
1746                 {
1747                   if (pfile->cb.used_undef)
1748                     pfile->cb.used_undef (pfile, pfile->directive_line, node);
1749                 }
1750             }
1751           check_eol (pfile, false);
1752         }
1753     }
1754
1755   push_conditional (pfile, skip, T_IFNDEF, node);
1756 }
1757
1758 /* _cpp_parse_expr puts a macro in a "#if !defined ()" expression in
1759    pfile->mi_ind_cmacro so we can handle multiple-include
1760    optimizations.  If macro expansion occurs in the expression, we
1761    cannot treat it as a controlling conditional, since the expansion
1762    could change in the future.  That is handled by cpp_get_token.  */
1763 static void
1764 do_if (cpp_reader *pfile)
1765 {
1766   int skip = 1;
1767
1768   if (! pfile->state.skipping)
1769     skip = _cpp_parse_expr (pfile, true) == false;
1770
1771   push_conditional (pfile, skip, T_IF, pfile->mi_ind_cmacro);
1772 }
1773
1774 /* Flip skipping state if appropriate and continue without changing
1775    if_stack; this is so that the error message for missing #endif's
1776    etc. will point to the original #if.  */
1777 static void
1778 do_else (cpp_reader *pfile)
1779 {
1780   cpp_buffer *buffer = pfile->buffer;
1781   struct if_stack *ifs = buffer->if_stack;
1782
1783   if (ifs == NULL)
1784     cpp_error (pfile, CPP_DL_ERROR, "#else without #if");
1785   else
1786     {
1787       if (ifs->type == T_ELSE)
1788         {
1789           cpp_error (pfile, CPP_DL_ERROR, "#else after #else");
1790           cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
1791                                "the conditional began here");
1792         }
1793       ifs->type = T_ELSE;
1794
1795       /* Skip any future (erroneous) #elses or #elifs.  */
1796       pfile->state.skipping = ifs->skip_elses;
1797       ifs->skip_elses = true;
1798
1799       /* Invalidate any controlling macro.  */
1800       ifs->mi_cmacro = 0;
1801
1802       /* Only check EOL if was not originally skipping.  */
1803       if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
1804         check_eol (pfile, false);
1805     }
1806 }
1807
1808 /* Handle a #elif directive by not changing if_stack either.  See the
1809    comment above do_else.  */
1810 static void
1811 do_elif (cpp_reader *pfile)
1812 {
1813   cpp_buffer *buffer = pfile->buffer;
1814   struct if_stack *ifs = buffer->if_stack;
1815
1816   if (ifs == NULL)
1817     cpp_error (pfile, CPP_DL_ERROR, "#elif without #if");
1818   else
1819     {
1820       if (ifs->type == T_ELSE)
1821         {
1822           cpp_error (pfile, CPP_DL_ERROR, "#elif after #else");
1823           cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
1824                                "the conditional began here");
1825         }
1826       ifs->type = T_ELIF;
1827
1828       if (! ifs->was_skipping)
1829         {
1830           bool value;
1831           /* The standard mandates that the expression be parsed even
1832              if we are skipping elses at this point -- the lexical
1833              restrictions on #elif only apply to skipped groups, but
1834              this group is not being skipped.  Temporarily set
1835              skipping to false to get lexer warnings.  */
1836           pfile->state.skipping = 0;
1837           value = _cpp_parse_expr (pfile, false);
1838           if (ifs->skip_elses)
1839             pfile->state.skipping = 1;
1840           else
1841             {
1842               pfile->state.skipping = ! value;
1843               ifs->skip_elses = value;
1844             }
1845         }
1846
1847       /* Invalidate any controlling macro.  */
1848       ifs->mi_cmacro = 0;
1849     }
1850 }
1851
1852 /* #endif pops the if stack and resets pfile->state.skipping.  */
1853 static void
1854 do_endif (cpp_reader *pfile)
1855 {
1856   cpp_buffer *buffer = pfile->buffer;
1857   struct if_stack *ifs = buffer->if_stack;
1858
1859   if (ifs == NULL)
1860     cpp_error (pfile, CPP_DL_ERROR, "#endif without #if");
1861   else
1862     {
1863       /* Only check EOL if was not originally skipping.  */
1864       if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
1865         check_eol (pfile, false);
1866
1867       /* If potential control macro, we go back outside again.  */
1868       if (ifs->next == 0 && ifs->mi_cmacro)
1869         {
1870           pfile->mi_valid = true;
1871           pfile->mi_cmacro = ifs->mi_cmacro;
1872         }
1873
1874       buffer->if_stack = ifs->next;
1875       pfile->state.skipping = ifs->was_skipping;
1876       obstack_free (&pfile->buffer_ob, ifs);
1877     }
1878 }
1879
1880 /* Push an if_stack entry for a preprocessor conditional, and set
1881    pfile->state.skipping to SKIP.  If TYPE indicates the conditional
1882    is #if or #ifndef, CMACRO is a potentially controlling macro, and
1883    we need to check here that we are at the top of the file.  */
1884 static void
1885 push_conditional (cpp_reader *pfile, int skip, int type,
1886                   const cpp_hashnode *cmacro)
1887 {
1888   struct if_stack *ifs;
1889   cpp_buffer *buffer = pfile->buffer;
1890
1891   ifs = XOBNEW (&pfile->buffer_ob, struct if_stack);
1892   ifs->line = pfile->directive_line;
1893   ifs->next = buffer->if_stack;
1894   ifs->skip_elses = pfile->state.skipping || !skip;
1895   ifs->was_skipping = pfile->state.skipping;
1896   ifs->type = type;
1897   /* This condition is effectively a test for top-of-file.  */
1898   if (pfile->mi_valid && pfile->mi_cmacro == 0)
1899     ifs->mi_cmacro = cmacro;
1900   else
1901     ifs->mi_cmacro = 0;
1902
1903   pfile->state.skipping = skip;
1904   buffer->if_stack = ifs;
1905 }
1906
1907 /* Read the tokens of the answer into the macro pool, in a directive
1908    of type TYPE.  Only commit the memory if we intend it as permanent
1909    storage, i.e. the #assert case.  Returns 0 on success, and sets
1910    ANSWERP to point to the answer.  PRED_LOC is the location of the
1911    predicate.  */
1912 static int
1913 parse_answer (cpp_reader *pfile, struct answer **answerp, int type,
1914               source_location pred_loc)
1915 {
1916   const cpp_token *paren;
1917   struct answer *answer;
1918   unsigned int acount;
1919
1920   /* In a conditional, it is legal to not have an open paren.  We
1921      should save the following token in this case.  */
1922   paren = cpp_get_token (pfile);
1923
1924   /* If not a paren, see if we're OK.  */
1925   if (paren->type != CPP_OPEN_PAREN)
1926     {
1927       /* In a conditional no answer is a test for any answer.  It
1928          could be followed by any token.  */
1929       if (type == T_IF)
1930         {
1931           _cpp_backup_tokens (pfile, 1);
1932           return 0;
1933         }
1934
1935       /* #unassert with no answer is valid - it removes all answers.  */
1936       if (type == T_UNASSERT && paren->type == CPP_EOF)
1937         return 0;
1938
1939       cpp_error_with_line (pfile, CPP_DL_ERROR, pred_loc, 0,
1940                            "missing '(' after predicate");
1941       return 1;
1942     }
1943
1944   for (acount = 0;; acount++)
1945     {
1946       size_t room_needed;
1947       const cpp_token *token = cpp_get_token (pfile);
1948       cpp_token *dest;
1949
1950       if (token->type == CPP_CLOSE_PAREN)
1951         break;
1952
1953       if (token->type == CPP_EOF)
1954         {
1955           cpp_error (pfile, CPP_DL_ERROR, "missing ')' to complete answer");
1956           return 1;
1957         }
1958
1959       /* struct answer includes the space for one token.  */
1960       room_needed = (sizeof (struct answer) + acount * sizeof (cpp_token));
1961
1962       if (BUFF_ROOM (pfile->a_buff) < room_needed)
1963         _cpp_extend_buff (pfile, &pfile->a_buff, sizeof (struct answer));
1964
1965       dest = &((struct answer *) BUFF_FRONT (pfile->a_buff))->first[acount];
1966       *dest = *token;
1967
1968       /* Drop whitespace at start, for answer equivalence purposes.  */
1969       if (acount == 0)
1970         dest->flags &= ~PREV_WHITE;
1971     }
1972
1973   if (acount == 0)
1974     {
1975       cpp_error (pfile, CPP_DL_ERROR, "predicate's answer is empty");
1976       return 1;
1977     }
1978
1979   answer = (struct answer *) BUFF_FRONT (pfile->a_buff);
1980   answer->count = acount;
1981   answer->next = NULL;
1982   *answerp = answer;
1983
1984   return 0;
1985 }
1986
1987 /* Parses an assertion directive of type TYPE, returning a pointer to
1988    the hash node of the predicate, or 0 on error.  If an answer was
1989    supplied, it is placed in ANSWERP, otherwise it is set to 0.  */
1990 static cpp_hashnode *
1991 parse_assertion (cpp_reader *pfile, struct answer **answerp, int type)
1992 {
1993   cpp_hashnode *result = 0;
1994   const cpp_token *predicate;
1995
1996   /* We don't expand predicates or answers.  */
1997   pfile->state.prevent_expansion++;
1998
1999   *answerp = 0;
2000   predicate = cpp_get_token (pfile);
2001   if (predicate->type == CPP_EOF)
2002     cpp_error (pfile, CPP_DL_ERROR, "assertion without predicate");
2003   else if (predicate->type != CPP_NAME)
2004     cpp_error_with_line (pfile, CPP_DL_ERROR, predicate->src_loc, 0,
2005                          "predicate must be an identifier");
2006   else if (parse_answer (pfile, answerp, type, predicate->src_loc) == 0)
2007     {
2008       unsigned int len = NODE_LEN (predicate->val.node.node);
2009       unsigned char *sym = (unsigned char *) alloca (len + 1);
2010
2011       /* Prefix '#' to get it out of macro namespace.  */
2012       sym[0] = '#';
2013       memcpy (sym + 1, NODE_NAME (predicate->val.node.node), len);
2014       result = cpp_lookup (pfile, sym, len + 1);
2015     }
2016
2017   pfile->state.prevent_expansion--;
2018   return result;
2019 }
2020
2021 /* Returns a pointer to the pointer to CANDIDATE in the answer chain,
2022    or a pointer to NULL if the answer is not in the chain.  */
2023 static struct answer **
2024 find_answer (cpp_hashnode *node, const struct answer *candidate)
2025 {
2026   unsigned int i;
2027   struct answer **result;
2028
2029   for (result = &node->value.answers; *result; result = &(*result)->next)
2030     {
2031       struct answer *answer = *result;
2032
2033       if (answer->count == candidate->count)
2034         {
2035           for (i = 0; i < answer->count; i++)
2036             if (! _cpp_equiv_tokens (&answer->first[i], &candidate->first[i]))
2037               break;
2038
2039           if (i == answer->count)
2040             break;
2041         }
2042     }
2043
2044   return result;
2045 }
2046
2047 /* Test an assertion within a preprocessor conditional.  Returns
2048    nonzero on failure, zero on success.  On success, the result of
2049    the test is written into VALUE, otherwise the value 0.  */
2050 int
2051 _cpp_test_assertion (cpp_reader *pfile, unsigned int *value)
2052 {
2053   struct answer *answer;
2054   cpp_hashnode *node;
2055
2056   node = parse_assertion (pfile, &answer, T_IF);
2057
2058   /* For recovery, an erroneous assertion expression is handled as a
2059      failing assertion.  */
2060   *value = 0;
2061
2062   if (node)
2063     *value = (node->type == NT_ASSERTION &&
2064               (answer == 0 || *find_answer (node, answer) != 0));
2065   else if (pfile->cur_token[-1].type == CPP_EOF)
2066     _cpp_backup_tokens (pfile, 1);
2067
2068   /* We don't commit the memory for the answer - it's temporary only.  */
2069   return node == 0;
2070 }
2071
2072 /* Handle #assert.  */
2073 static void
2074 do_assert (cpp_reader *pfile)
2075 {
2076   struct answer *new_answer;
2077   cpp_hashnode *node;
2078
2079   node = parse_assertion (pfile, &new_answer, T_ASSERT);
2080   if (node)
2081     {
2082       size_t answer_size;
2083
2084       /* Place the new answer in the answer list.  First check there
2085          is not a duplicate.  */
2086       new_answer->next = 0;
2087       if (node->type == NT_ASSERTION)
2088         {
2089           if (*find_answer (node, new_answer))
2090             {
2091               cpp_error (pfile, CPP_DL_WARNING, "\"%s\" re-asserted",
2092                          NODE_NAME (node) + 1);
2093               return;
2094             }
2095           new_answer->next = node->value.answers;
2096         }
2097
2098       answer_size = sizeof (struct answer) + ((new_answer->count - 1)
2099                                               * sizeof (cpp_token));
2100       /* Commit or allocate storage for the object.  */
2101       if (pfile->hash_table->alloc_subobject)
2102         {
2103           struct answer *temp_answer = new_answer;
2104           new_answer = (struct answer *) pfile->hash_table->alloc_subobject
2105             (answer_size);
2106           memcpy (new_answer, temp_answer, answer_size);
2107         }
2108       else
2109         BUFF_FRONT (pfile->a_buff) += answer_size;
2110
2111       node->type = NT_ASSERTION;
2112       node->value.answers = new_answer;
2113       check_eol (pfile, false);
2114     }
2115 }
2116
2117 /* Handle #unassert.  */
2118 static void
2119 do_unassert (cpp_reader *pfile)
2120 {
2121   cpp_hashnode *node;
2122   struct answer *answer;
2123
2124   node = parse_assertion (pfile, &answer, T_UNASSERT);
2125   /* It isn't an error to #unassert something that isn't asserted.  */
2126   if (node && node->type == NT_ASSERTION)
2127     {
2128       if (answer)
2129         {
2130           struct answer **p = find_answer (node, answer), *temp;
2131
2132           /* Remove the answer from the list.  */
2133           temp = *p;
2134           if (temp)
2135             *p = temp->next;
2136
2137           /* Did we free the last answer?  */
2138           if (node->value.answers == 0)
2139             node->type = NT_VOID;
2140
2141           check_eol (pfile, false);
2142         }
2143       else
2144         _cpp_free_definition (node);
2145     }
2146
2147   /* We don't commit the memory for the answer - it's temporary only.  */
2148 }
2149
2150 /* These are for -D, -U, -A.  */
2151
2152 /* Process the string STR as if it appeared as the body of a #define.
2153    If STR is just an identifier, define it with value 1.
2154    If STR has anything after the identifier, then it should
2155    be identifier=definition.  */
2156 void
2157 cpp_define (cpp_reader *pfile, const char *str)
2158 {
2159   char *buf, *p;
2160   size_t count;
2161
2162   /* Copy the entire option so we can modify it.
2163      Change the first "=" in the string to a space.  If there is none,
2164      tack " 1" on the end.  */
2165
2166   count = strlen (str);
2167   buf = (char *) alloca (count + 3);
2168   memcpy (buf, str, count);
2169
2170   p = strchr (str, '=');
2171   if (p)
2172     buf[p - str] = ' ';
2173   else
2174     {
2175       buf[count++] = ' ';
2176       buf[count++] = '1';
2177     }
2178   buf[count] = '\n';
2179
2180   run_directive (pfile, T_DEFINE, buf, count);
2181 }
2182
2183
2184 /* Use to build macros to be run through cpp_define() as
2185    described above.
2186    Example: cpp_define_formatted (pfile, "MACRO=%d", value);  */
2187
2188 void
2189 cpp_define_formatted (cpp_reader *pfile, const char *fmt, ...)
2190 {
2191   char *ptr = NULL;
2192
2193   va_list ap;
2194   va_start (ap, fmt);
2195   vasprintf (&ptr, fmt, ap);
2196   va_end (ap);
2197
2198   cpp_define (pfile, ptr);
2199   free (ptr);
2200 }
2201
2202
2203 /* Slight variant of the above for use by initialize_builtins.  */
2204 void
2205 _cpp_define_builtin (cpp_reader *pfile, const char *str)
2206 {
2207   size_t len = strlen (str);
2208   char *buf = (char *) alloca (len + 1);
2209   memcpy (buf, str, len);
2210   buf[len] = '\n';
2211   run_directive (pfile, T_DEFINE, buf, len);
2212 }
2213
2214 /* Process MACRO as if it appeared as the body of an #undef.  */
2215 void
2216 cpp_undef (cpp_reader *pfile, const char *macro)
2217 {
2218   size_t len = strlen (macro);
2219   char *buf = (char *) alloca (len + 1);
2220   memcpy (buf, macro, len);
2221   buf[len] = '\n';
2222   run_directive (pfile, T_UNDEF, buf, len);
2223 }
2224
2225 /* Like lex_macro_node, but read the input from STR.  */
2226 static cpp_hashnode *
2227 lex_macro_node_from_str (cpp_reader *pfile, const char *str)
2228 {
2229   size_t len = strlen (str);
2230   uchar *buf = (uchar *) alloca (len + 1);
2231   cpp_hashnode *node;
2232
2233   memcpy (buf, str, len);
2234   buf[len] = '\n';
2235   cpp_push_buffer (pfile, buf, len, true);
2236   node = lex_macro_node (pfile, true);
2237   _cpp_pop_buffer (pfile);
2238
2239   return node;
2240 }
2241
2242 /* If STR is a defined macro, return its definition node, else return NULL.  */
2243 cpp_macro *
2244 cpp_push_definition (cpp_reader *pfile, const char *str)
2245 {
2246   cpp_hashnode *node = lex_macro_node_from_str (pfile, str);
2247   if (node && node->type == NT_MACRO)
2248     return node->value.macro;
2249   else
2250     return NULL;
2251 }
2252
2253 /* Replace a previous definition DFN of the macro STR.  If DFN is NULL,
2254    then the macro should be undefined.  */
2255 void
2256 cpp_pop_definition (cpp_reader *pfile, const char *str, cpp_macro *dfn)
2257 {
2258   cpp_hashnode *node = lex_macro_node_from_str (pfile, str);
2259   if (node == NULL)
2260     return;
2261
2262   if (pfile->cb.before_define)
2263     pfile->cb.before_define (pfile);
2264
2265   if (node->type == NT_MACRO)
2266     {
2267       if (pfile->cb.undef)
2268         pfile->cb.undef (pfile, pfile->directive_line, node);
2269       if (CPP_OPTION (pfile, warn_unused_macros))
2270         _cpp_warn_if_unused_macro (pfile, node, NULL);
2271     }
2272   if (node->type != NT_VOID)
2273     _cpp_free_definition (node);
2274
2275   if (dfn)
2276     {
2277       node->type = NT_MACRO;
2278       node->value.macro = dfn;
2279       if (! ustrncmp (NODE_NAME (node), DSC ("__STDC_")))
2280         node->flags |= NODE_WARN;
2281
2282       if (pfile->cb.define)
2283         pfile->cb.define (pfile, pfile->directive_line, node);
2284     }
2285 }
2286
2287 /* Process the string STR as if it appeared as the body of a #assert.  */
2288 void
2289 cpp_assert (cpp_reader *pfile, const char *str)
2290 {
2291   handle_assertion (pfile, str, T_ASSERT);
2292 }
2293
2294 /* Process STR as if it appeared as the body of an #unassert.  */
2295 void
2296 cpp_unassert (cpp_reader *pfile, const char *str)
2297 {
2298   handle_assertion (pfile, str, T_UNASSERT);
2299 }
2300
2301 /* Common code for cpp_assert (-A) and cpp_unassert (-A-).  */
2302 static void
2303 handle_assertion (cpp_reader *pfile, const char *str, int type)
2304 {
2305   size_t count = strlen (str);
2306   const char *p = strchr (str, '=');
2307
2308   /* Copy the entire option so we can modify it.  Change the first
2309      "=" in the string to a '(', and tack a ')' on the end.  */
2310   char *buf = (char *) alloca (count + 2);
2311
2312   memcpy (buf, str, count);
2313   if (p)
2314     {
2315       buf[p - str] = '(';
2316       buf[count++] = ')';
2317     }
2318   buf[count] = '\n';
2319   str = buf;
2320
2321   run_directive (pfile, type, str, count);
2322 }
2323
2324 /* The options structure.  */
2325 cpp_options *
2326 cpp_get_options (cpp_reader *pfile)
2327 {
2328   return &pfile->opts;
2329 }
2330
2331 /* The callbacks structure.  */
2332 cpp_callbacks *
2333 cpp_get_callbacks (cpp_reader *pfile)
2334 {
2335   return &pfile->cb;
2336 }
2337
2338 /* Copy the given callbacks structure to our own.  */
2339 void
2340 cpp_set_callbacks (cpp_reader *pfile, cpp_callbacks *cb)
2341 {
2342   pfile->cb = *cb;
2343 }
2344
2345 /* The dependencies structure.  (Creates one if it hasn't already been.)  */
2346 struct deps *
2347 cpp_get_deps (cpp_reader *pfile)
2348 {
2349   if (!pfile->deps)
2350     pfile->deps = deps_init ();
2351   return pfile->deps;
2352 }
2353
2354 /* Push a new buffer on the buffer stack.  Returns the new buffer; it
2355    doesn't fail.  It does not generate a file change call back; that
2356    is the responsibility of the caller.  */
2357 cpp_buffer *
2358 cpp_push_buffer (cpp_reader *pfile, const uchar *buffer, size_t len,
2359                  int from_stage3)
2360 {
2361   cpp_buffer *new_buffer = XOBNEW (&pfile->buffer_ob, cpp_buffer);
2362
2363   /* Clears, amongst other things, if_stack and mi_cmacro.  */
2364   memset (new_buffer, 0, sizeof (cpp_buffer));
2365
2366   new_buffer->next_line = new_buffer->buf = buffer;
2367   new_buffer->rlimit = buffer + len;
2368   new_buffer->from_stage3 = from_stage3;
2369   new_buffer->prev = pfile->buffer;
2370   new_buffer->need_line = true;
2371
2372   pfile->buffer = new_buffer;
2373
2374   return new_buffer;
2375 }
2376
2377 /* Pops a single buffer, with a file change call-back if appropriate.
2378    Then pushes the next -include file, if any remain.  */
2379 void
2380 _cpp_pop_buffer (cpp_reader *pfile)
2381 {
2382   cpp_buffer *buffer = pfile->buffer;
2383   struct _cpp_file *inc = buffer->file;
2384   struct if_stack *ifs;
2385
2386   /* Walk back up the conditional stack till we reach its level at
2387      entry to this file, issuing error messages.  */
2388   for (ifs = buffer->if_stack; ifs; ifs = ifs->next)
2389     cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0,
2390                          "unterminated #%s", dtable[ifs->type].name);
2391
2392   /* In case of a missing #endif.  */
2393   pfile->state.skipping = 0;
2394
2395   /* _cpp_do_file_change expects pfile->buffer to be the new one.  */
2396   pfile->buffer = buffer->prev;
2397
2398   free (buffer->notes);
2399
2400   /* Free the buffer object now; we may want to push a new buffer
2401      in _cpp_push_next_include_file.  */
2402   obstack_free (&pfile->buffer_ob, buffer);
2403
2404   if (inc)
2405     {
2406       _cpp_pop_file_buffer (pfile, inc);
2407
2408       _cpp_do_file_change (pfile, LC_LEAVE, 0, 0, 0);
2409     }
2410 }
2411
2412 /* Enter all recognized directives in the hash table.  */
2413 void
2414 _cpp_init_directives (cpp_reader *pfile)
2415 {
2416   unsigned int i;
2417   cpp_hashnode *node;
2418
2419   for (i = 0; i < (unsigned int) N_DIRECTIVES; i++)
2420     {
2421       node = cpp_lookup (pfile, dtable[i].name, dtable[i].length);
2422       node->is_directive = 1;
2423       node->directive_index = i;
2424     }
2425 }