gcc/cpplib.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 Free Software Foundation, Inc.
   4    Contributed by Per Bothner, 1994-95.
   5    Based on CCCP program by Paul Rubin, June 1986
   6    Adapted to ANSI C, Richard Stallman, Jan 1987
   7
   8 This program is free software; you can redistribute it and/or modify it
   9 under the terms of the GNU General Public License as published by the
  10 Free Software Foundation; either version 2, or (at your option) any
  11 later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26
  27 #include "cpplib.h"
  28 #include "cpphash.h"
  29 #include "obstack.h"
  30
  31 /* Chained list of answers to an assertion.  */
  32 struct answer
  33 {
  34   struct answer *next;
  35   unsigned int count;
  36   cpp_token first[1];
  37 };
  38
  39 /* Stack of conditionals currently in progress
  40    (including both successful and failing conditionals).  */
  41 struct if_stack
  42 {
  43   struct if_stack *next;
  44   unsigned int line;            /* Line where condition started.  */
  45   const cpp_hashnode *mi_cmacro;/* macro name for #ifndef around entire file */
  46   bool skip_elses;              /* Can future #else / #elif be skipped?  */
  47   bool was_skipping;            /* If were skipping on entry.  */
  48   int type;                     /* Most recent conditional, for diagnostics.  */
  49 };
  50
  51 /* Contains a registered pragma or pragma namespace.  */
  52 typedef void (*pragma_cb) PARAMS ((cpp_reader *));
  53 struct pragma_entry
  54 {
  55   struct pragma_entry *next;
  56   const cpp_hashnode *pragma;   /* Name and length.  */
  57   int is_nspace;
  58   union {
  59     pragma_cb handler;
  60     struct pragma_entry *space;
  61   } u;
  62 };
  63
  64 /* Values for the origin field of struct directive.  KANDR directives
  65    come from traditional (K&R) C.  STDC89 directives come from the
  66    1989 C standard.  EXTENSION directives are extensions.  */
  67 #define KANDR           0
  68 #define STDC89          1
  69 #define EXTENSION       2
  70
  71 /* Values for the flags field of struct directive.  COND indicates a
  72    conditional; IF_COND an opening conditional.  INCL means to treat
  73    "..." and <...> as q-char and h-char sequences respectively.  IN_I
  74    means this directive should be handled even if -fpreprocessed is in
  75    effect (these are the directives with callback hooks).
  76
  77    EXPAND is set on directives that are always macro-expanded.  */
  78 #define COND            (1 << 0)
  79 #define IF_COND         (1 << 1)
  80 #define INCL            (1 << 2)
  81 #define IN_I            (1 << 3)
  82 #define EXPAND          (1 << 4)
  83
  84 /* Defines one #-directive, including how to handle it.  */
  85 typedef void (*directive_handler) PARAMS ((cpp_reader *));
  86 typedef struct directive directive;
  87 struct directive
  88 {
  89   directive_handler handler;    /* Function to handle directive.  */
  90   const uchar *name;            /* Name of directive.  */
  91   unsigned short length;        /* Length of name.  */
  92   unsigned char origin;         /* Origin of directive.  */
  93   unsigned char flags;          /* Flags describing this directive.  */
  94 };
  95
  96 /* Forward declarations.  */
  97
  98 static void skip_rest_of_line   PARAMS ((cpp_reader *));
  99 static void check_eol           PARAMS ((cpp_reader *));
 100 static void start_directive     PARAMS ((cpp_reader *));
 101 static void prepare_directive_trad PARAMS ((cpp_reader *));
 102 static void end_directive       PARAMS ((cpp_reader *, int));
 103 static void directive_diagnostics
 104         PARAMS ((cpp_reader *, const directive *, int));
 105 static void run_directive       PARAMS ((cpp_reader *, int,
 106                                          const char *, size_t));
 107 static const cpp_token *glue_header_name PARAMS ((cpp_reader *));
 108 static const cpp_token *parse_include PARAMS ((cpp_reader *));
 109 static void push_conditional    PARAMS ((cpp_reader *, int, int,
 110                                          const cpp_hashnode *));
 111 static unsigned int read_flag   PARAMS ((cpp_reader *, unsigned int));
 112 static uchar *dequote_string    PARAMS ((cpp_reader *, const uchar *,
 113                                          unsigned int));
 114 static int  strtoul_for_line    PARAMS ((const uchar *, unsigned int,
 115                                          unsigned long *));
 116 static void do_diagnostic       PARAMS ((cpp_reader *, int, int));
 117 static cpp_hashnode *lex_macro_node     PARAMS ((cpp_reader *));
 118 static void do_include_common   PARAMS ((cpp_reader *, enum include_type));
 119 static struct pragma_entry *lookup_pragma_entry
 120   PARAMS ((struct pragma_entry *, const cpp_hashnode *pragma));
 121 static struct pragma_entry *insert_pragma_entry
 122   PARAMS ((cpp_reader *, struct pragma_entry **, const cpp_hashnode *,
 123            pragma_cb));
 124 static int count_registered_pragmas     PARAMS ((struct pragma_entry *));
 125 static char ** save_registered_pragmas
 126   PARAMS ((struct pragma_entry *, char **));
 127 static char ** restore_registered_pragmas
 128   PARAMS ((cpp_reader *, struct pragma_entry *, char **));
 129 static void do_pragma_once      PARAMS ((cpp_reader *));
 130 static void do_pragma_poison    PARAMS ((cpp_reader *));
 131 static void do_pragma_system_header     PARAMS ((cpp_reader *));
 132 static void do_pragma_dependency        PARAMS ((cpp_reader *));
 133 static void do_linemarker               PARAMS ((cpp_reader *));
 134 static const cpp_token *get_token_no_padding PARAMS ((cpp_reader *));
 135 static const cpp_token *get__Pragma_string PARAMS ((cpp_reader *));
 136 static void destringize_and_run PARAMS ((cpp_reader *, const cpp_string *));
 137 static int parse_answer PARAMS ((cpp_reader *, struct answer **, int));
 138 static cpp_hashnode *parse_assertion PARAMS ((cpp_reader *, struct answer **,
 139                                               int));
 140 static struct answer ** find_answer PARAMS ((cpp_hashnode *,
 141                                              const struct answer *));
 142 static void handle_assertion    PARAMS ((cpp_reader *, const char *, int));
 143
 144 /* This is the table of directive handlers.  It is ordered by
 145    frequency of occurrence; the numbers at the end are directive
 146    counts from all the source code I have lying around (egcs and libc
 147    CVS as of 1999-05-18, plus grub-0.5.91, linux-2.2.9, and
 148    pcmcia-cs-3.0.9).  This is no longer important as directive lookup
 149    is now O(1).  All extensions other than #warning and #include_next
 150    are deprecated.  The name is where the extension appears to have
 151    come from.  */
 152
 153 #define DIRECTIVE_TABLE                                                 \
 154 D(define,       T_DEFINE = 0,   KANDR,     IN_I)           /* 270554 */ \
 155 D(include,      T_INCLUDE,      KANDR,     INCL | EXPAND)  /*  52262 */ \
 156 D(endif,        T_ENDIF,        KANDR,     COND)           /*  45855 */ \
 157 D(ifdef,        T_IFDEF,        KANDR,     COND | IF_COND) /*  22000 */ \
 158 D(if,           T_IF,           KANDR, COND | IF_COND | EXPAND) /*  18162 */ \
 159 D(else,         T_ELSE,         KANDR,     COND)           /*   9863 */ \
 160 D(ifndef,       T_IFNDEF,       KANDR,     COND | IF_COND) /*   9675 */ \
 161 D(undef,        T_UNDEF,        KANDR,     IN_I)           /*   4837 */ \
 162 D(line,         T_LINE,         KANDR,     EXPAND)         /*   2465 */ \
 163 D(elif,         T_ELIF,         STDC89,    COND | EXPAND)  /*    610 */ \
 164 D(error,        T_ERROR,        STDC89,    0)              /*    475 */ \
 165 D(pragma,       T_PRAGMA,       STDC89,    IN_I)           /*    195 */ \
 166 D(warning,      T_WARNING,      EXTENSION, 0)              /*     22 */ \
 167 D(include_next, T_INCLUDE_NEXT, EXTENSION, INCL | EXPAND)  /*     19 */ \
 168 D(ident,        T_IDENT,        EXTENSION, IN_I)           /*     11 */ \
 169 D(import,       T_IMPORT,       EXTENSION, INCL | EXPAND)  /* 0 ObjC */ \
 170 D(assert,       T_ASSERT,       EXTENSION, 0)              /* 0 SVR4 */ \
 171 D(unassert,     T_UNASSERT,     EXTENSION, 0)              /* 0 SVR4 */ \
 172 D(sccs,         T_SCCS,         EXTENSION, 0)              /* 0 SVR4? */
 173
 174 /* Use the table to generate a series of prototypes, an enum for the
 175    directive names, and an array of directive handlers.  */
 176
 177 /* Don't invoke CONCAT2 with any whitespace or K&R cc will fail.  */
 178 #define D(name, t, o, f) static void CONCAT2(do_,name) PARAMS ((cpp_reader *));
 179 DIRECTIVE_TABLE
 180 #undef D
 181
 182 #define D(n, tag, o, f) tag,
 183 enum
 184 {
 185   DIRECTIVE_TABLE
 186   N_DIRECTIVES
 187 };
 188 #undef D
 189
 190 /* Don't invoke CONCAT2 with any whitespace or K&R cc will fail.  */
 191 #define D(name, t, origin, flags) \
 192 { CONCAT2(do_,name), (const uchar *) STRINGX(name), \
 193   sizeof STRINGX(name) - 1, origin, flags },
 194 static const directive dtable[] =
 195 {
 196 DIRECTIVE_TABLE
 197 };
 198 #undef D
 199 #undef DIRECTIVE_TABLE
 200
 201 /* Wrapper struct directive for linemarkers.
 202    The origin is more or less true - the original K+R cpp
 203    did use this notation in its preprocessed output.  */
 204 static const directive linemarker_dir =
 205 {
 206   do_linemarker, U"#", 1, KANDR, IN_I
 207 };
 208
 209 #define SEEN_EOL() (pfile->cur_token[-1].type == CPP_EOF)
 210
 211 /* Skip any remaining tokens in a directive.  */
 212 static void
 213 skip_rest_of_line (pfile)
 214      cpp_reader *pfile;
 215 {
 216   /* Discard all stacked contexts.  */
 217   while (pfile->context->prev)
 218     _cpp_pop_context (pfile);
 219
 220   /* Sweep up all tokens remaining on the line.  */
 221   if (! SEEN_EOL ())
 222     while (_cpp_lex_token (pfile)->type != CPP_EOF)
 223       ;
 224 }
 225
 226 /* Ensure there are no stray tokens at the end of a directive.  */
 227 static void
 228 check_eol (pfile)
 229      cpp_reader *pfile;
 230 {
 231   if (! SEEN_EOL () && _cpp_lex_token (pfile)->type != CPP_EOF)
 232     cpp_error (pfile, DL_PEDWARN, "extra tokens at end of #%s directive",
 233                pfile->directive->name);
 234 }
 235
 236 /* Called when entering a directive, _Pragma or command-line directive.  */
 237 static void
 238 start_directive (pfile)
 239      cpp_reader *pfile;
 240 {
 241   /* Setup in-directive state.  */
 242   pfile->state.in_directive = 1;
 243   pfile->state.save_comments = 0;
 244
 245   /* Some handlers need the position of the # for diagnostics.  */
 246   pfile->directive_line = pfile->line;
 247 }
 248
 249 /* Called when leaving a directive, _Pragma or command-line directive.  */
 250 static void
 251 end_directive (pfile, skip_line)
 252      cpp_reader *pfile;
 253      int skip_line;
 254 {
 255   if (CPP_OPTION (pfile, traditional))
 256     {
 257       /* Revert change of prepare_directive_trad.  */
 258       pfile->state.prevent_expansion--;
 259
 260       if (pfile->directive != &dtable[T_DEFINE])
 261         _cpp_remove_overlay (pfile);
 262     }
 263   /* We don't skip for an assembler #.  */
 264   else if (skip_line)
 265     {
 266       skip_rest_of_line (pfile);
 267       if (!pfile->keep_tokens)
 268         {
 269           pfile->cur_run = &pfile->base_run;
 270           pfile->cur_token = pfile->base_run.base;
 271         }
 272     }
 273
 274   /* Restore state.  */
 275   pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments);
 276   pfile->state.in_directive = 0;
 277   pfile->state.in_expression = 0;
 278   pfile->state.angled_headers = 0;
 279   pfile->directive = 0;
 280 }
 281
 282 /* Prepare to handle the directive in pfile->directive.  */
 283 static void
 284 prepare_directive_trad (pfile)
 285      cpp_reader *pfile;
 286 {
 287   if (pfile->directive != &dtable[T_DEFINE])
 288     {
 289       bool no_expand = (pfile->directive
 290                         && ! (pfile->directive->flags & EXPAND));
 291       bool was_skipping = pfile->state.skipping;
 292
 293       pfile->state.skipping = false;
 294       pfile->state.in_expression = (pfile->directive == &dtable[T_IF]
 295                                     || pfile->directive == &dtable[T_ELIF]);
 296       if (no_expand)
 297         pfile->state.prevent_expansion++;
 298       _cpp_read_logical_line_trad (pfile);
 299       if (no_expand)
 300         pfile->state.prevent_expansion--;
 301       pfile->state.skipping = was_skipping;
 302       _cpp_overlay_buffer (pfile, pfile->out.base,
 303                            pfile->out.cur - pfile->out.base);
 304     }
 305
 306   /* Stop ISO C from expanding anything.  */
 307   pfile->state.prevent_expansion++;
 308 }
 309
 310 /* Output diagnostics for a directive DIR.  INDENTED is nonzero if
 311    the '#' was indented.  */
 312 static void
 313 directive_diagnostics (pfile, dir, indented)
 314      cpp_reader *pfile;
 315      const directive *dir;
 316      int indented;
 317 {
 318   /* Issue -pedantic warnings for extensions.  */
 319   if (CPP_PEDANTIC (pfile)
 320       && ! pfile->state.skipping
 321       && dir->origin == EXTENSION)
 322     cpp_error (pfile, DL_PEDWARN, "#%s is a GCC extension", dir->name);
 323
 324   /* Traditionally, a directive is ignored unless its # is in
 325      column 1.  Therefore in code intended to work with K+R
 326      compilers, directives added by C89 must have their #
 327      indented, and directives present in traditional C must not.
 328      This is true even of directives in skipped conditional
 329      blocks.  #elif cannot be used at all.  */
 330   if (CPP_WTRADITIONAL (pfile))
 331     {
 332       if (dir == &dtable[T_ELIF])
 333         cpp_error (pfile, DL_WARNING,
 334                    "suggest not using #elif in traditional C");
 335       else if (indented && dir->origin == KANDR)
 336         cpp_error (pfile, DL_WARNING,
 337                    "traditional C ignores #%s with the # indented",
 338                    dir->name);
 339       else if (!indented && dir->origin != KANDR)
 340         cpp_error (pfile, DL_WARNING,
 341                    "suggest hiding #%s from traditional C with an indented #",
 342                    dir->name);
 343     }
 344 }
 345
 346 /* Check if we have a known directive.  INDENTED is nonzero if the
 347    '#' of the directive was indented.  This function is in this file
 348    to save unnecessarily exporting dtable etc. to cpplex.c.  Returns
 349    nonzero if the line of tokens has been handled, zero if we should
 350    continue processing the line.  */
 351 int
 352 _cpp_handle_directive (pfile, indented)
 353      cpp_reader *pfile;
 354      int indented;
 355 {
 356   const directive *dir = 0;
 357   const cpp_token *dname;
 358   bool was_parsing_args = pfile->state.parsing_args;
 359   int skip = 1;
 360
 361   if (was_parsing_args)
 362     {
 363       if (CPP_OPTION (pfile, pedantic))
 364         cpp_error (pfile, DL_PEDWARN,
 365              "embedding a directive within macro arguments is not portable");
 366       pfile->state.parsing_args = 0;
 367       pfile->state.prevent_expansion = 0;
 368     }
 369   start_directive (pfile);
 370   dname = _cpp_lex_token (pfile);
 371
 372   if (dname->type == CPP_NAME)
 373     {
 374       if (dname->val.node->is_directive)
 375         dir = &dtable[dname->val.node->directive_index];
 376     }
 377   /* We do not recognize the # followed by a number extension in
 378      assembler code.  */
 379   else if (dname->type == CPP_NUMBER && CPP_OPTION (pfile, lang) != CLK_ASM)
 380     {
 381       dir = &linemarker_dir;
 382       if (CPP_PEDANTIC (pfile) && ! CPP_OPTION (pfile, preprocessed)
 383           && ! pfile->state.skipping)
 384         cpp_error (pfile, DL_PEDWARN,
 385                    "style of line directive is a GCC extension");
 386     }
 387
 388   if (dir)
 389     {
 390       /* If we have a directive that is not an opening conditional,
 391          invalidate any control macro.  */
 392       if (! (dir->flags & IF_COND))
 393         pfile->mi_valid = false;
 394
 395       /* Kluge alert.  In order to be sure that code like this
 396
 397          #define HASH #
 398          HASH define foo bar
 399
 400          does not cause '#define foo bar' to get executed when
 401          compiled with -save-temps, we recognize directives in
 402          -fpreprocessed mode only if the # is in column 1.  cppmacro.c
 403          puts a space in front of any '#' at the start of a macro.  */
 404       if (CPP_OPTION (pfile, preprocessed)
 405           && (indented || !(dir->flags & IN_I)))
 406         {
 407           skip = 0;
 408           dir = 0;
 409         }
 410       else
 411         {
 412           /* In failed conditional groups, all non-conditional
 413              directives are ignored.  Before doing that, whether
 414              skipping or not, we should lex angle-bracketed headers
 415              correctly, and maybe output some diagnostics.  */
 416           pfile->state.angled_headers = dir->flags & INCL;
 417           pfile->state.directive_wants_padding = dir->flags & INCL;
 418           if (! CPP_OPTION (pfile, preprocessed))
 419             directive_diagnostics (pfile, dir, indented);
 420           if (pfile->state.skipping && !(dir->flags & COND))
 421             dir = 0;
 422         }
 423     }
 424   else if (dname->type == CPP_EOF)
 425     ;   /* CPP_EOF is the "null directive".  */
 426   else
 427     {
 428       /* An unknown directive.  Don't complain about it in assembly
 429          source: we don't know where the comments are, and # may
 430          introduce assembler pseudo-ops.  Don't complain about invalid
 431          directives in skipped conditional groups (6.10 p4).  */
 432       if (CPP_OPTION (pfile, lang) == CLK_ASM)
 433         skip = 0;
 434       else if (!pfile->state.skipping)
 435         cpp_error (pfile, DL_ERROR, "invalid preprocessing directive #%s",
 436                    cpp_token_as_text (pfile, dname));
 437     }
 438
 439   pfile->directive = dir;
 440   if (CPP_OPTION (pfile, traditional))
 441     prepare_directive_trad (pfile);
 442
 443   if (dir)
 444     (*pfile->directive->handler) (pfile);
 445   else if (skip == 0)
 446     _cpp_backup_tokens (pfile, 1);
 447
 448   end_directive (pfile, skip);
 449   if (was_parsing_args)
 450     {
 451       /* Restore state when within macro args.  */
 452       pfile->state.parsing_args = 2;
 453       pfile->state.prevent_expansion = 1;
 454       pfile->buffer->saved_flags |= PREV_WHITE;
 455     }
 456   return skip;
 457 }
 458
 459 /* Directive handler wrapper used by the command line option
 460    processor.  */
 461 static void
 462 run_directive (pfile, dir_no, buf, count)
 463      cpp_reader *pfile;
 464      int dir_no;
 465      const char *buf;
 466      size_t count;
 467 {
 468   cpp_push_buffer (pfile, (const uchar *) buf, count,
 469                    /* from_stage3 */ true, 1);
 470   /* Disgusting hack.  */
 471   if (dir_no == T_PRAGMA)
 472     pfile->buffer->inc = pfile->buffer->prev->inc;
 473   start_directive (pfile);
 474   /* We don't want a leading # to be interpreted as a directive.  */
 475   pfile->buffer->saved_flags = 0;
 476   pfile->directive = &dtable[dir_no];
 477   if (CPP_OPTION (pfile, traditional))
 478     prepare_directive_trad (pfile);
 479   (void) (*pfile->directive->handler) (pfile);
 480   end_directive (pfile, 1);
 481   if (dir_no == T_PRAGMA)
 482     pfile->buffer->inc = NULL;
 483   _cpp_pop_buffer (pfile);
 484 }
 485
 486 /* Checks for validity the macro name in #define, #undef, #ifdef and
 487    #ifndef directives.  */
 488 static cpp_hashnode *
 489 lex_macro_node (pfile)
 490      cpp_reader *pfile;
 491 {
 492   const cpp_token *token = _cpp_lex_token (pfile);
 493
 494   /* The token immediately after #define must be an identifier.  That
 495      identifier may not be "defined", per C99 6.10.8p4.
 496      In C++, it may not be any of the "named operators" either,
 497      per C++98 [lex.digraph], [lex.key].
 498      Finally, the identifier may not have been poisoned.  (In that case
 499      the lexer has issued the error message for us.)  */
 500
 501   if (token->type == CPP_NAME)
 502     {
 503       cpp_hashnode *node = token->val.node;
 504
 505       if (node == pfile->spec_nodes.n_defined)
 506         cpp_error (pfile, DL_ERROR,
 507                    "\"defined\" cannot be used as a macro name");
 508       else if (! (node->flags & NODE_POISONED))
 509         return node;
 510     }
 511   else if (token->flags & NAMED_OP)
 512     cpp_error (pfile, DL_ERROR,
 513        "\"%s\" cannot be used as a macro name as it is an operator in C++",
 514                NODE_NAME (token->val.node));
 515   else if (token->type == CPP_EOF)
 516     cpp_error (pfile, DL_ERROR, "no macro name given in #%s directive",
 517                pfile->directive->name);
 518   else
 519     cpp_error (pfile, DL_ERROR, "macro names must be identifiers");
 520
 521   return NULL;
 522 }
 523
 524 /* Process a #define directive.  Most work is done in cppmacro.c.  */
 525 static void
 526 do_define (pfile)
 527      cpp_reader *pfile;
 528 {
 529   cpp_hashnode *node = lex_macro_node (pfile);
 530
 531   if (node)
 532     {
 533       /* If we have been requested to expand comments into macros,
 534          then re-enable saving of comments.  */
 535       pfile->state.save_comments =
 536         ! CPP_OPTION (pfile, discard_comments_in_macro_exp);
 537
 538       if (_cpp_create_definition (pfile, node))
 539         if (pfile->cb.define)
 540           (*pfile->cb.define) (pfile, pfile->directive_line, node);
 541     }
 542 }
 543
 544 /* Handle #undef.  Mark the identifier NT_VOID in the hash table.  */
 545 static void
 546 do_undef (pfile)
 547      cpp_reader *pfile;
 548 {
 549   cpp_hashnode *node = lex_macro_node (pfile);
 550
 551   /* 6.10.3.5 paragraph 2: [#undef] is ignored if the specified identifier
 552      is not currently defined as a macro name.  */
 553   if (node && node->type == NT_MACRO)
 554     {
 555       if (pfile->cb.undef)
 556         (*pfile->cb.undef) (pfile, pfile->directive_line, node);
 557
 558       if (node->flags & NODE_WARN)
 559         cpp_error (pfile, DL_WARNING, "undefining \"%s\"", NODE_NAME (node));
 560
 561       if (CPP_OPTION (pfile, warn_unused_macros))
 562         _cpp_warn_if_unused_macro (pfile, node, NULL);
 563
 564       _cpp_free_definition (node);
 565     }
 566   check_eol (pfile);
 567 }
 568
 569 /* Helper routine used by parse_include.  Reinterpret the current line
 570    as an h-char-sequence (< ... >); we are looking at the first token
 571    after the <.  Returns the header as a token, or NULL on failure.  */
 572 static const cpp_token *
 573 glue_header_name (pfile)
 574      cpp_reader *pfile;
 575 {
 576   cpp_token *header = NULL;
 577   const cpp_token *token;
 578   unsigned char *buffer;
 579   size_t len, total_len = 0, capacity = 1024;
 580
 581   /* To avoid lexed tokens overwriting our glued name, we can only
 582      allocate from the string pool once we've lexed everything.  */
 583   buffer = (unsigned char *) xmalloc (capacity);
 584   for (;;)
 585     {
 586       token = get_token_no_padding (pfile);
 587
 588       if (token->type == CPP_GREATER || token->type == CPP_EOF)
 589         break;
 590
 591       len = cpp_token_len (token);
 592       if (total_len + len > capacity)
 593         {
 594           capacity = (capacity + len) * 2;
 595           buffer = (unsigned char *) xrealloc (buffer, capacity);
 596         }
 597
 598       if (token->flags & PREV_WHITE)
 599         buffer[total_len++] = ' ';
 600
 601       total_len = cpp_spell_token (pfile, token, &buffer[total_len]) - buffer;
 602     }
 603
 604   if (token->type == CPP_EOF)
 605     cpp_error (pfile, DL_ERROR, "missing terminating > character");
 606   else
 607     {
 608       unsigned char *token_mem = _cpp_unaligned_alloc (pfile, total_len + 1);
 609       memcpy (token_mem, buffer, total_len);
 610       token_mem[total_len] = '\0';
 611
 612       header = _cpp_temp_token (pfile);
 613       header->type = CPP_HEADER_NAME;
 614       header->flags = 0;
 615       header->val.str.len = total_len;
 616       header->val.str.text = token_mem;
 617     }
 618
 619   free ((PTR) buffer);
 620   return header;
 621 }
 622
 623 /* Returns the header string of #include, #include_next, #import and
 624    #pragma dependency.  Returns NULL on error.  */
 625 static const cpp_token *
 626 parse_include (pfile)
 627      cpp_reader *pfile;
 628 {
 629   const unsigned char *dir;
 630   const cpp_token *header;
 631
 632   if (pfile->directive == &dtable[T_PRAGMA])
 633     dir = U"pragma dependency";
 634   else
 635     dir = pfile->directive->name;
 636
 637   /* Allow macro expansion.  */
 638   header = get_token_no_padding (pfile);
 639   if (header->type != CPP_STRING && header->type != CPP_HEADER_NAME)
 640     {
 641       if (header->type != CPP_LESS)
 642         {
 643           cpp_error (pfile, DL_ERROR,
 644                      "#%s expects \"FILENAME\" or <FILENAME>", dir);
 645           return NULL;
 646         }
 647
 648       header = glue_header_name (pfile);
 649       if (header == NULL)
 650         return header;
 651     }
 652
 653   if (header->val.str.len == 0)
 654     {
 655       cpp_error (pfile, DL_ERROR, "empty file name in #%s", dir);
 656       return NULL;
 657     }
 658
 659   check_eol (pfile);
 660   return header;
 661 }
 662
 663 /* Handle #include, #include_next and #import.  */
 664 static void
 665 do_include_common (pfile, type)
 666      cpp_reader *pfile;
 667      enum include_type type;
 668 {
 669   const cpp_token *header = parse_include (pfile);
 670   if (!header)
 671     return;
 672
 673   /* Prevent #include recursion.  */
 674   if (pfile->line_maps.depth >= CPP_STACK_MAX)
 675     {
 676       cpp_error (pfile, DL_ERROR, "#include nested too deeply");
 677       return;
 678     }
 679
 680   /* Get out of macro context, if we are.  */
 681   skip_rest_of_line (pfile);
 682
 683   if (pfile->cb.include)
 684     (*pfile->cb.include) (pfile, pfile->directive_line,
 685                           pfile->directive->name, header);
 686
 687   _cpp_execute_include (pfile, header, type);
 688 }
 689
 690 static void
 691 do_include (pfile)
 692      cpp_reader *pfile;
 693 {
 694   do_include_common (pfile, IT_INCLUDE);
 695 }
 696
 697 static void
 698 do_import (pfile)
 699      cpp_reader *pfile;
 700 {
 701   if (CPP_OPTION (pfile, warn_import))
 702     {
 703       CPP_OPTION (pfile, warn_import) = 0;
 704       cpp_error (pfile, DL_WARNING,
 705    "#import is obsolete, use an #ifndef wrapper in the header file");
 706     }
 707
 708   do_include_common (pfile, IT_IMPORT);
 709 }
 710
 711 static void
 712 do_include_next (pfile)
 713      cpp_reader *pfile;
 714 {
 715   enum include_type type = IT_INCLUDE_NEXT;
 716
 717   /* If this is the primary source file, warn and use the normal
 718      search logic.  */
 719   if (! pfile->buffer->prev)
 720     {
 721       cpp_error (pfile, DL_WARNING,
 722                  "#include_next in primary source file");
 723       type = IT_INCLUDE;
 724     }
 725   do_include_common (pfile, type);
 726 }
 727
 728 /* Subroutine of do_linemarker.  Read possible flags after file name.
 729    LAST is the last flag seen; 0 if this is the first flag. Return the
 730    flag if it is valid, 0 at the end of the directive. Otherwise
 731    complain.  */
 732 static unsigned int
 733 read_flag (pfile, last)
 734      cpp_reader *pfile;
 735      unsigned int last;
 736 {
 737   const cpp_token *token = _cpp_lex_token (pfile);
 738
 739   if (token->type == CPP_NUMBER && token->val.str.len == 1)
 740     {
 741       unsigned int flag = token->val.str.text[0] - '0';
 742
 743       if (flag > last && flag <= 4
 744           && (flag != 4 || last == 3)
 745           && (flag != 2 || last == 0))
 746         return flag;
 747     }
 748
 749   if (token->type != CPP_EOF)
 750     cpp_error (pfile, DL_ERROR, "invalid flag \"%s\" in line directive",
 751                cpp_token_as_text (pfile, token));
 752   return 0;
 753 }
 754
 755 /* Subroutine of do_line and do_linemarker.  Returns a version of STR
 756    which has a NUL terminator and all escape sequences converted to
 757    their equivalents.  Temporary, hopefully.  */
 758 static uchar *
 759 dequote_string (pfile, str, len)
 760      cpp_reader *pfile;
 761      const uchar *str;
 762      unsigned int len;
 763 {
 764   uchar *result = _cpp_unaligned_alloc (pfile, len + 1);
 765   uchar *dst = result;
 766   const uchar *limit = str + len;
 767   cppchar_t c;
 768
 769   while (str < limit)
 770     {
 771       c = *str++;
 772       if (c != '\\')
 773         *dst++ = c;
 774       else
 775         *dst++ = cpp_parse_escape (pfile, &str, limit, 0);
 776     }
 777   *dst++ = '\0';
 778   return result;
 779 }
 780
 781 /* Subroutine of do_line and do_linemarker.  Convert a number in STR,
 782    of length LEN, to binary; store it in NUMP, and return 0 if the
 783    number was well-formed, 1 if not.  Temporary, hopefully.  */
 784 static int
 785 strtoul_for_line (str, len, nump)
 786      const uchar *str;
 787      unsigned int len;
 788      unsigned long *nump;
 789 {
 790   unsigned long reg = 0;
 791   uchar c;
 792   while (len--)
 793     {
 794       c = *str++;
 795       if (!ISDIGIT (c))
 796         return 1;
 797       reg *= 10;
 798       reg += c - '0';
 799     }
 800   *nump = reg;
 801   return 0;
 802 }
 803
 804 /* Interpret #line command.
 805    Note that the filename string (if any) is a true string constant
 806    (escapes are interpreted), unlike in #line.  */
 807 static void
 808 do_line (pfile)
 809      cpp_reader *pfile;
 810 {
 811   const cpp_token *token;
 812   const char *new_file = pfile->map->to_file;
 813   unsigned long new_lineno;
 814
 815   /* C99 raised the minimum limit on #line numbers.  */
 816   unsigned int cap = CPP_OPTION (pfile, c99) ? 2147483647 : 32767;
 817
 818   /* #line commands expand macros.  */
 819   token = cpp_get_token (pfile);
 820   if (token->type != CPP_NUMBER
 821       || strtoul_for_line (token->val.str.text, token->val.str.len,
 822                            &new_lineno))
 823     {
 824       cpp_error (pfile, DL_ERROR,
 825                  "\"%s\" after #line is not a positive integer",
 826                  cpp_token_as_text (pfile, token));
 827       return;
 828     }
 829
 830   if (CPP_PEDANTIC (pfile) && (new_lineno == 0 || new_lineno > cap))
 831     cpp_error (pfile, DL_PEDWARN, "line number out of range");
 832
 833   token = cpp_get_token (pfile);
 834   if (token->type == CPP_STRING)
 835     {
 836       new_file = (const char *) dequote_string (pfile, token->val.str.text,
 837                                                 token->val.str.len);
 838       check_eol (pfile);
 839     }
 840   else if (token->type != CPP_EOF)
 841     {
 842       cpp_error (pfile, DL_ERROR, "\"%s\" is not a valid filename",
 843                  cpp_token_as_text (pfile, token));
 844       return;
 845     }
 846
 847   skip_rest_of_line (pfile);
 848   _cpp_do_file_change (pfile, LC_RENAME, new_file, new_lineno,
 849                        pfile->map->sysp);
 850 }
 851
 852 /* Interpret the # 44 "file" [flags] notation, which has slightly
 853    different syntax and semantics from #line:  Flags are allowed,
 854    and we never complain about the line number being too big.  */
 855 static void
 856 do_linemarker (pfile)
 857      cpp_reader *pfile;
 858 {
 859   const cpp_token *token;
 860   const char *new_file = pfile->map->to_file;
 861   unsigned long new_lineno;
 862   unsigned int new_sysp = pfile->map->sysp;
 863   enum lc_reason reason = LC_RENAME;
 864   int flag;
 865
 866   /* Back up so we can get the number again.  Putting this in
 867      _cpp_handle_directive risks two calls to _cpp_backup_tokens in
 868      some circumstances, which can segfault.  */
 869   _cpp_backup_tokens (pfile, 1);
 870
 871   /* #line commands expand macros.  */
 872   token = cpp_get_token (pfile);
 873   if (token->type != CPP_NUMBER
 874       || strtoul_for_line (token->val.str.text, token->val.str.len,
 875                            &new_lineno))
 876     {
 877       cpp_error (pfile, DL_ERROR, "\"%s\" after # is not a positive integer",
 878                  cpp_token_as_text (pfile, token));
 879       return;
 880     }
 881
 882   token = cpp_get_token (pfile);
 883   if (token->type == CPP_STRING)
 884     {
 885       new_file = (const char *) dequote_string (pfile, token->val.str.text,
 886                                                 token->val.str.len);
 887       new_sysp = 0;
 888       flag = read_flag (pfile, 0);
 889       if (flag == 1)
 890         {
 891           reason = LC_ENTER;
 892           /* Fake an include for cpp_included ().  */
 893           _cpp_fake_include (pfile, new_file);
 894           flag = read_flag (pfile, flag);
 895         }
 896       else if (flag == 2)
 897         {
 898           reason = LC_LEAVE;
 899           flag = read_flag (pfile, flag);
 900         }
 901       if (flag == 3)
 902         {
 903           new_sysp = 1;
 904           flag = read_flag (pfile, flag);
 905           if (flag == 4)
 906             new_sysp = 2;
 907         }
 908
 909       check_eol (pfile);
 910     }
 911   else if (token->type != CPP_EOF)
 912     {
 913       cpp_error (pfile, DL_ERROR, "\"%s\" is not a valid filename",
 914                  cpp_token_as_text (pfile, token));
 915       return;
 916     }
 917
 918   skip_rest_of_line (pfile);
 919   _cpp_do_file_change (pfile, reason, new_file, new_lineno, new_sysp);
 920 }
 921
 922 /* Arrange the file_change callback.  pfile->line has changed to
 923    FILE_LINE of TO_FILE, for reason REASON.  SYSP is 1 for a system
 924    header, 2 for a system header that needs to be extern "C" protected,
 925    and zero otherwise.  */
 926 void
 927 _cpp_do_file_change (pfile, reason, to_file, file_line, sysp)
 928      cpp_reader *pfile;
 929      enum lc_reason reason;
 930      const char *to_file;
 931      unsigned int file_line;
 932      unsigned int sysp;
 933 {
 934   pfile->map = add_line_map (&pfile->line_maps, reason, sysp,
 935                              pfile->line, to_file, file_line);
 936
 937   if (pfile->cb.file_change)
 938     (*pfile->cb.file_change) (pfile, pfile->map);
 939 }
 940
 941 /* Report a warning or error detected by the program we are
 942    processing.  Use the directive's tokens in the error message.  */
 943 static void
 944 do_diagnostic (pfile, code, print_dir)
 945      cpp_reader *pfile;
 946      int code;
 947      int print_dir;
 948 {
 949   if (_cpp_begin_message (pfile, code,
 950                           pfile->cur_token[-1].line,
 951                           pfile->cur_token[-1].col))
 952     {
 953       if (print_dir)
 954         fprintf (stderr, "#%s ", pfile->directive->name);
 955       pfile->state.prevent_expansion++;
 956       cpp_output_line (pfile, stderr);
 957       pfile->state.prevent_expansion--;
 958     }
 959 }
 960
 961 static void
 962 do_error (pfile)
 963      cpp_reader *pfile;
 964 {
 965   do_diagnostic (pfile, DL_ERROR, 1);
 966 }
 967
 968 static void
 969 do_warning (pfile)
 970      cpp_reader *pfile;
 971 {
 972   /* We want #warning diagnostics to be emitted in system headers too.  */
 973   do_diagnostic (pfile, DL_WARNING_SYSHDR, 1);
 974 }
 975
 976 /* Report program identification.  */
 977 static void
 978 do_ident (pfile)
 979      cpp_reader *pfile;
 980 {
 981   const cpp_token *str = cpp_get_token (pfile);
 982
 983   if (str->type != CPP_STRING)
 984     cpp_error (pfile, DL_ERROR, "invalid #ident directive");
 985   else if (pfile->cb.ident)
 986     (*pfile->cb.ident) (pfile, pfile->directive_line, &str->val.str);
 987
 988   check_eol (pfile);
 989 }
 990
 991 /* Lookup a PRAGMA name in a singly-linked CHAIN.  Returns the
 992    matching entry, or NULL if none is found.  The returned entry could
 993    be the start of a namespace chain, or a pragma.  */
 994 static struct pragma_entry *
 995 lookup_pragma_entry (chain, pragma)
 996      struct pragma_entry *chain;
 997      const cpp_hashnode *pragma;
 998 {
 999   while (chain && chain->pragma != pragma)
1000     chain = chain->next;
1001
1002   return chain;
1003 }
1004
1005 /* Create and insert a pragma entry for NAME at the beginning of a
1006    singly-linked CHAIN.  If handler is NULL, it is a namespace,
1007    otherwise it is a pragma and its handler.  */
1008 static struct pragma_entry *
1009 insert_pragma_entry (pfile, chain, pragma, handler)
1010      cpp_reader *pfile;
1011      struct pragma_entry **chain;
1012      const cpp_hashnode *pragma;
1013      pragma_cb handler;
1014 {
1015   struct pragma_entry *new;
1016
1017   new = (struct pragma_entry *)
1018     _cpp_aligned_alloc (pfile, sizeof (struct pragma_entry));
1019   new->pragma = pragma;
1020   if (handler)
1021     {
1022       new->is_nspace = 0;
1023       new->u.handler = handler;
1024     }
1025   else
1026     {
1027       new->is_nspace = 1;
1028       new->u.space = NULL;
1029     }
1030
1031   new->next = *chain;
1032   *chain = new;
1033   return new;
1034 }
1035
1036 /* Register a pragma NAME in namespace SPACE.  If SPACE is null, it
1037    goes in the global namespace.  HANDLER is the handler it will call,
1038    which must be non-NULL.  */
1039 void
1040 cpp_register_pragma (pfile, space, name, handler)
1041      cpp_reader *pfile;
1042      const char *space;
1043      const char *name;
1044      pragma_cb handler;
1045 {
1046   struct pragma_entry **chain = &pfile->pragmas;
1047   struct pragma_entry *entry;
1048   const cpp_hashnode *node;
1049
1050   if (!handler)
1051     abort ();
1052
1053   if (space)
1054     {
1055       node = cpp_lookup (pfile, U space, strlen (space));
1056       entry = lookup_pragma_entry (*chain, node);
1057       if (!entry)
1058         entry = insert_pragma_entry (pfile, chain, node, NULL);
1059       else if (!entry->is_nspace)
1060         goto clash;
1061       chain = &entry->u.space;
1062     }
1063
1064   /* Check for duplicates.  */
1065   node = cpp_lookup (pfile, U name, strlen (name));
1066   entry = lookup_pragma_entry (*chain, node);
1067   if (entry)
1068     {
1069       if (entry->is_nspace)
1070         clash:
1071         cpp_error (pfile, DL_ICE,
1072                  "registering \"%s\" as both a pragma and a pragma namespace",
1073                  NODE_NAME (node));
1074       else if (space)
1075         cpp_error (pfile, DL_ICE, "#pragma %s %s is already registered",
1076                    space, name);
1077       else
1078         cpp_error (pfile, DL_ICE, "#pragma %s is already registered", name);
1079     }
1080   else
1081     insert_pragma_entry (pfile, chain, node, handler);
1082 }
1083
1084 /* Register the pragmas the preprocessor itself handles.  */
1085 void
1086 _cpp_init_internal_pragmas (pfile)
1087      cpp_reader *pfile;
1088 {
1089   /* Pragmas in the global namespace.  */
1090   cpp_register_pragma (pfile, 0, "once", do_pragma_once);
1091
1092   /* New GCC-specific pragmas should be put in the GCC namespace.  */
1093   cpp_register_pragma (pfile, "GCC", "poison", do_pragma_poison);
1094   cpp_register_pragma (pfile, "GCC", "system_header", do_pragma_system_header);
1095   cpp_register_pragma (pfile, "GCC", "dependency", do_pragma_dependency);
1096 }
1097
1098 /* Return the number of registered pragmas in PE.  */
1099
1100 static int
1101 count_registered_pragmas (pe)
1102      struct pragma_entry *pe;
1103 {
1104   int ct = 0;
1105   for (; pe != NULL; pe = pe->next)
1106     {
1107       if (pe->is_nspace)
1108         ct += count_registered_pragmas (pe->u.space);
1109       ct++;
1110     }
1111   return ct;
1112 }
1113
1114 /* Save into SD the names of the registered pragmas referenced by PE,
1115    and return a pointer to the next free space in SD.  */
1116
1117 static char **
1118 save_registered_pragmas (pe, sd)
1119      struct pragma_entry *pe;
1120      char **sd;
1121 {
1122   for (; pe != NULL; pe = pe->next)
1123     {
1124       if (pe->is_nspace)
1125         sd = save_registered_pragmas (pe->u.space, sd);
1126       *sd++ = xmemdup (HT_STR (&pe->pragma->ident),
1127                        HT_LEN (&pe->pragma->ident),
1128                        HT_LEN (&pe->pragma->ident) + 1);
1129     }
1130   return sd;
1131 }
1132
1133 /* Return a newly-allocated array which saves the names of the
1134    registered pragmas.  */
1135
1136 char **
1137 _cpp_save_pragma_names (pfile)
1138      cpp_reader *pfile;
1139 {
1140   int ct = count_registered_pragmas (pfile->pragmas);
1141   char **result = xnewvec (char *, ct);
1142   (void) save_registered_pragmas (pfile->pragmas, result);
1143   return result;
1144 }
1145
1146 /* Restore from SD the names of the registered pragmas referenced by PE,
1147    and return a pointer to the next unused name in SD.  */
1148
1149 static char **
1150 restore_registered_pragmas (pfile, pe, sd)
1151      cpp_reader *pfile;
1152      struct pragma_entry *pe;
1153      char **sd;
1154 {
1155   for (; pe != NULL; pe = pe->next)
1156     {
1157       if (pe->is_nspace)
1158         sd = restore_registered_pragmas (pfile, pe->u.space, sd);
1159       pe->pragma = cpp_lookup (pfile, U *sd, strlen (*sd));
1160       free (*sd);
1161       sd++;
1162     }
1163   return sd;
1164 }
1165
1166 /* Restore the names of the registered pragmas from SAVED.  */
1167
1168 void
1169 _cpp_restore_pragma_names (pfile, saved)
1170      cpp_reader *pfile;
1171      char **saved;
1172 {
1173   (void) restore_registered_pragmas (pfile, pfile->pragmas, saved);
1174   free (saved);
1175 }
1176
1177 /* Pragmata handling.  We handle some, and pass the rest on to the
1178    front end.  C99 defines three pragmas and says that no macro
1179    expansion is to be performed on them; whether or not macro
1180    expansion happens for other pragmas is implementation defined.
1181    This implementation never macro-expands the text after #pragma.  */
1182 static void
1183 do_pragma (pfile)
1184      cpp_reader *pfile;
1185 {
1186   const struct pragma_entry *p = NULL;
1187   const cpp_token *token;
1188   unsigned int count = 1;
1189
1190   pfile->state.prevent_expansion++;
1191
1192   token = cpp_get_token (pfile);
1193   if (token->type == CPP_NAME)
1194     {
1195       p = lookup_pragma_entry (pfile->pragmas, token->val.node);
1196       if (p && p->is_nspace)
1197         {
1198           count = 2;
1199           token = cpp_get_token (pfile);
1200           if (token->type == CPP_NAME)
1201             p = lookup_pragma_entry (p->u.space, token->val.node);
1202           else
1203             p = NULL;
1204         }
1205     }
1206
1207   /* FIXME.  This is an awful kludge to get the front ends to update
1208      their notion of line number for diagnostic purposes.  The line
1209      number should be passed to the handler and they should do it
1210      themselves.  Stand-alone CPP must ignore us, otherwise it will
1211      prefix the directive with spaces, hence the 1.  Ugh.  */
1212   if (pfile->cb.line_change)
1213     (*pfile->cb.line_change)(pfile, token, 1);
1214
1215   if (p)
1216     (*p->u.handler) (pfile);
1217   else if (pfile->cb.def_pragma)
1218     {
1219       _cpp_backup_tokens (pfile, count);
1220       (*pfile->cb.def_pragma) (pfile, pfile->directive_line);
1221     }
1222
1223   pfile->state.prevent_expansion--;
1224 }
1225
1226 /* Handle #pragma once.  */
1227 static void
1228 do_pragma_once (pfile)
1229      cpp_reader *pfile;
1230 {
1231   if (CPP_OPTION (pfile, warn_deprecated))
1232     cpp_error (pfile, DL_WARNING, "#pragma once is obsolete");
1233
1234   if (pfile->buffer->prev == NULL)
1235     cpp_error (pfile, DL_WARNING, "#pragma once in main file");
1236   else
1237     _cpp_never_reread (pfile->buffer->inc);
1238
1239   check_eol (pfile);
1240 }
1241
1242 /* Handle #pragma GCC poison, to poison one or more identifiers so
1243    that the lexer produces a hard error for each subsequent usage.  */
1244 static void
1245 do_pragma_poison (pfile)
1246      cpp_reader *pfile;
1247 {
1248   const cpp_token *tok;
1249   cpp_hashnode *hp;
1250
1251   pfile->state.poisoned_ok = 1;
1252   for (;;)
1253     {
1254       tok = _cpp_lex_token (pfile);
1255       if (tok->type == CPP_EOF)
1256         break;
1257       if (tok->type != CPP_NAME)
1258         {
1259           cpp_error (pfile, DL_ERROR, "invalid #pragma GCC poison directive");
1260           break;
1261         }
1262
1263       hp = tok->val.node;
1264       if (hp->flags & NODE_POISONED)
1265         continue;
1266
1267       if (hp->type == NT_MACRO)
1268         cpp_error (pfile, DL_WARNING, "poisoning existing macro \"%s\"",
1269                    NODE_NAME (hp));
1270       _cpp_free_definition (hp);
1271       hp->flags |= NODE_POISONED | NODE_DIAGNOSTIC;
1272     }
1273   pfile->state.poisoned_ok = 0;
1274 }
1275
1276 /* Mark the current header as a system header.  This will suppress
1277    some categories of warnings (notably those from -pedantic).  It is
1278    intended for use in system libraries that cannot be implemented in
1279    conforming C, but cannot be certain that their headers appear in a
1280    system include directory.  To prevent abuse, it is rejected in the
1281    primary source file.  */
1282 static void
1283 do_pragma_system_header (pfile)
1284      cpp_reader *pfile;
1285 {
1286   cpp_buffer *buffer = pfile->buffer;
1287
1288   if (buffer->prev == 0)
1289     cpp_error (pfile, DL_WARNING,
1290                "#pragma system_header ignored outside include file");
1291   else
1292     {
1293       check_eol (pfile);
1294       skip_rest_of_line (pfile);
1295       cpp_make_system_header (pfile, 1, 0);
1296     }
1297 }
1298
1299 /* Check the modified date of the current include file against a specified
1300    file. Issue a diagnostic, if the specified file is newer. We use this to
1301    determine if a fixed header should be refixed.  */
1302 static void
1303 do_pragma_dependency (pfile)
1304      cpp_reader *pfile;
1305 {
1306   const cpp_token *header;
1307   int ordering;
1308
1309   header = parse_include (pfile);
1310   if (!header)
1311     return;
1312
1313   ordering = _cpp_compare_file_date (pfile, header);
1314   if (ordering < 0)
1315     cpp_error (pfile, DL_WARNING, "cannot find source %s",
1316                cpp_token_as_text (pfile, header));
1317   else if (ordering > 0)
1318     {
1319       cpp_error (pfile, DL_WARNING, "current file is older than %s",
1320                  cpp_token_as_text (pfile, header));
1321       if (cpp_get_token (pfile)->type != CPP_EOF)
1322         {
1323           _cpp_backup_tokens (pfile, 1);
1324           do_diagnostic (pfile, DL_WARNING, 0);
1325         }
1326     }
1327 }
1328
1329 /* Get a token but skip padding.  */
1330 static const cpp_token *
1331 get_token_no_padding (pfile)
1332      cpp_reader *pfile;
1333 {
1334   for (;;)
1335     {
1336       const cpp_token *result = cpp_get_token (pfile);
1337       if (result->type != CPP_PADDING)
1338         return result;
1339     }
1340 }
1341
1342 /* Check syntax is "(string-literal)".  Returns the string on success,
1343    or NULL on failure.  */
1344 static const cpp_token *
1345 get__Pragma_string (pfile)
1346      cpp_reader *pfile;
1347 {
1348   const cpp_token *string;
1349
1350   if (get_token_no_padding (pfile)->type != CPP_OPEN_PAREN)
1351     return NULL;
1352
1353   string = get_token_no_padding (pfile);
1354   if (string->type != CPP_STRING && string->type != CPP_WSTRING)
1355     return NULL;
1356
1357   if (get_token_no_padding (pfile)->type != CPP_CLOSE_PAREN)
1358     return NULL;
1359
1360   return string;
1361 }
1362
1363 /* Destringize IN into a temporary buffer, by removing the first \ of
1364    \" and \\ sequences, and process the result as a #pragma directive.  */
1365 static void
1366 destringize_and_run (pfile, in)
1367      cpp_reader *pfile;
1368      const cpp_string *in;
1369 {
1370   const unsigned char *src, *limit;
1371   char *dest, *result;
1372
1373   dest = result = alloca (in->len + 1);
1374   for (src = in->text, limit = src + in->len; src < limit;)
1375     {
1376       /* We know there is a character following the backslash.  */
1377       if (*src == '\\' && (src[1] == '\\' || src[1] == '"'))
1378         src++;
1379       *dest++ = *src++;
1380     }
1381   *dest = '\0';
1382
1383   /* Ugh; an awful kludge.  We are really not set up to be lexing
1384      tokens when in the middle of a macro expansion.  Use a new
1385      context to force cpp_get_token to lex, and so skip_rest_of_line
1386      doesn't go beyond the end of the text.  Also, remember the
1387      current lexing position so we can return to it later.
1388
1389      Something like line-at-a-time lexing should remove the need for
1390      this.  */
1391   {
1392     cpp_context *saved_context = pfile->context;
1393     cpp_token *saved_cur_token = pfile->cur_token;
1394     tokenrun *saved_cur_run = pfile->cur_run;
1395
1396     pfile->context = xnew (cpp_context);
1397     pfile->context->macro = 0;
1398     pfile->context->prev = 0;
1399     run_directive (pfile, T_PRAGMA, result, dest - result);
1400     free (pfile->context);
1401     pfile->context = saved_context;
1402     pfile->cur_token = saved_cur_token;
1403     pfile->cur_run = saved_cur_run;
1404     pfile->line--;
1405   }
1406
1407   /* See above comment.  For the moment, we'd like
1408
1409      token1 _Pragma ("foo") token2
1410
1411      to be output as
1412
1413                 token1
1414                 # 7 "file.c"
1415                 #pragma foo
1416                 # 7 "file.c"
1417                                token2
1418
1419       Getting the line markers is a little tricky.  */
1420   if (pfile->cb.line_change)
1421     (*pfile->cb.line_change) (pfile, pfile->cur_token, false);
1422 }
1423
1424 /* Handle the _Pragma operator.  */
1425 void
1426 _cpp_do__Pragma (pfile)
1427      cpp_reader *pfile;
1428 {
1429   const cpp_token *string = get__Pragma_string (pfile);
1430
1431   if (string)
1432     destringize_and_run (pfile, &string->val.str);
1433   else
1434     cpp_error (pfile, DL_ERROR,
1435                "_Pragma takes a parenthesized string literal");
1436 }
1437
1438 /* Just ignore #sccs on all systems.  */
1439 static void
1440 do_sccs (pfile)
1441      cpp_reader *pfile ATTRIBUTE_UNUSED;
1442 {
1443 }
1444
1445 /* Handle #ifdef.  */
1446 static void
1447 do_ifdef (pfile)
1448      cpp_reader *pfile;
1449 {
1450   int skip = 1;
1451
1452   if (! pfile->state.skipping)
1453     {
1454       const cpp_hashnode *node = lex_macro_node (pfile);
1455
1456       if (node)
1457         {
1458           skip = node->type != NT_MACRO;
1459           _cpp_mark_macro_used (node);
1460           check_eol (pfile);
1461         }
1462     }
1463
1464   push_conditional (pfile, skip, T_IFDEF, 0);
1465 }
1466
1467 /* Handle #ifndef.  */
1468 static void
1469 do_ifndef (pfile)
1470      cpp_reader *pfile;
1471 {
1472   int skip = 1;
1473   const cpp_hashnode *node = 0;
1474
1475   if (! pfile->state.skipping)
1476     {
1477       node = lex_macro_node (pfile);
1478
1479       if (node)
1480         {
1481           skip = node->type == NT_MACRO;
1482           _cpp_mark_macro_used (node);
1483           check_eol (pfile);
1484         }
1485     }
1486
1487   push_conditional (pfile, skip, T_IFNDEF, node);
1488 }
1489
1490 /* _cpp_parse_expr puts a macro in a "#if !defined ()" expression in
1491    pfile->mi_ind_cmacro so we can handle multiple-include
1492    optimisations.  If macro expansion occurs in the expression, we
1493    cannot treat it as a controlling conditional, since the expansion
1494    could change in the future.  That is handled by cpp_get_token.  */
1495 static void
1496 do_if (pfile)
1497      cpp_reader *pfile;
1498 {
1499   int skip = 1;
1500
1501   if (! pfile->state.skipping)
1502     skip = _cpp_parse_expr (pfile) == false;
1503
1504   push_conditional (pfile, skip, T_IF, pfile->mi_ind_cmacro);
1505 }
1506
1507 /* Flip skipping state if appropriate and continue without changing
1508    if_stack; this is so that the error message for missing #endif's
1509    etc. will point to the original #if.  */
1510 static void
1511 do_else (pfile)
1512      cpp_reader *pfile;
1513 {
1514   cpp_buffer *buffer = pfile->buffer;
1515   struct if_stack *ifs = buffer->if_stack;
1516
1517   if (ifs == NULL)
1518     cpp_error (pfile, DL_ERROR, "#else without #if");
1519   else
1520     {
1521       if (ifs->type == T_ELSE)
1522         {
1523           cpp_error (pfile, DL_ERROR, "#else after #else");
1524           cpp_error_with_line (pfile, DL_ERROR, ifs->line, 0,
1525                                "the conditional began here");
1526         }
1527       ifs->type = T_ELSE;
1528
1529       /* Skip any future (erroneous) #elses or #elifs.  */
1530       pfile->state.skipping = ifs->skip_elses;
1531       ifs->skip_elses = true;
1532
1533       /* Invalidate any controlling macro.  */
1534       ifs->mi_cmacro = 0;
1535
1536       /* Only check EOL if was not originally skipping.  */
1537       if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
1538         check_eol (pfile);
1539     }
1540 }
1541
1542 /* Handle a #elif directive by not changing if_stack either.  See the
1543    comment above do_else.  */
1544 static void
1545 do_elif (pfile)
1546      cpp_reader *pfile;
1547 {
1548   cpp_buffer *buffer = pfile->buffer;
1549   struct if_stack *ifs = buffer->if_stack;
1550
1551   if (ifs == NULL)
1552     cpp_error (pfile, DL_ERROR, "#elif without #if");
1553   else
1554     {
1555       if (ifs->type == T_ELSE)
1556         {
1557           cpp_error (pfile, DL_ERROR, "#elif after #else");
1558           cpp_error_with_line (pfile, DL_ERROR, ifs->line, 0,
1559                                "the conditional began here");
1560         }
1561       ifs->type = T_ELIF;
1562
1563       /* Only evaluate this if we aren't skipping elses.  During
1564          evaluation, set skipping to false to get lexer warnings.  */
1565       if (ifs->skip_elses)
1566         pfile->state.skipping = 1;
1567       else
1568         {
1569           pfile->state.skipping = 0;
1570           pfile->state.skipping = ! _cpp_parse_expr (pfile);
1571           ifs->skip_elses = ! pfile->state.skipping;
1572         }
1573
1574       /* Invalidate any controlling macro.  */
1575       ifs->mi_cmacro = 0;
1576     }
1577 }
1578
1579 /* #endif pops the if stack and resets pfile->state.skipping.  */
1580 static void
1581 do_endif (pfile)
1582      cpp_reader *pfile;
1583 {
1584   cpp_buffer *buffer = pfile->buffer;
1585   struct if_stack *ifs = buffer->if_stack;
1586
1587   if (ifs == NULL)
1588     cpp_error (pfile, DL_ERROR, "#endif without #if");
1589   else
1590     {
1591       /* Only check EOL if was not originally skipping.  */
1592       if (!ifs->was_skipping && CPP_OPTION (pfile, warn_endif_labels))
1593         check_eol (pfile);
1594
1595       /* If potential control macro, we go back outside again.  */
1596       if (ifs->next == 0 && ifs->mi_cmacro)
1597         {
1598           pfile->mi_valid = true;
1599           pfile->mi_cmacro = ifs->mi_cmacro;
1600         }
1601
1602       buffer->if_stack = ifs->next;
1603       pfile->state.skipping = ifs->was_skipping;
1604       obstack_free (&pfile->buffer_ob, ifs);
1605     }
1606 }
1607
1608 /* Push an if_stack entry for a preprocessor conditional, and set
1609    pfile->state.skipping to SKIP.  If TYPE indicates the conditional
1610    is #if or #ifndef, CMACRO is a potentially controlling macro, and
1611    we need to check here that we are at the top of the file.  */
1612 static void
1613 push_conditional (pfile, skip, type, cmacro)
1614      cpp_reader *pfile;
1615      int skip;
1616      int type;
1617      const cpp_hashnode *cmacro;
1618 {
1619   struct if_stack *ifs;
1620   cpp_buffer *buffer = pfile->buffer;
1621
1622   ifs = xobnew (&pfile->buffer_ob, struct if_stack);
1623   ifs->line = pfile->directive_line;
1624   ifs->next = buffer->if_stack;
1625   ifs->skip_elses = pfile->state.skipping || !skip;
1626   ifs->was_skipping = pfile->state.skipping;
1627   ifs->type = type;
1628   /* This condition is effectively a test for top-of-file.  */
1629   if (pfile->mi_valid && pfile->mi_cmacro == 0)
1630     ifs->mi_cmacro = cmacro;
1631   else
1632     ifs->mi_cmacro = 0;
1633
1634   pfile->state.skipping = skip;
1635   buffer->if_stack = ifs;
1636 }
1637
1638 /* Read the tokens of the answer into the macro pool, in a directive
1639    of type TYPE.  Only commit the memory if we intend it as permanent
1640    storage, i.e. the #assert case.  Returns 0 on success, and sets
1641    ANSWERP to point to the answer.  */
1642 static int
1643 parse_answer (pfile, answerp, type)
1644      cpp_reader *pfile;
1645      struct answer **answerp;
1646      int type;
1647 {
1648   const cpp_token *paren;
1649   struct answer *answer;
1650   unsigned int acount;
1651
1652   /* In a conditional, it is legal to not have an open paren.  We
1653      should save the following token in this case.  */
1654   paren = cpp_get_token (pfile);
1655
1656   /* If not a paren, see if we're OK.  */
1657   if (paren->type != CPP_OPEN_PAREN)
1658     {
1659       /* In a conditional no answer is a test for any answer.  It
1660          could be followed by any token.  */
1661       if (type == T_IF)
1662         {
1663           _cpp_backup_tokens (pfile, 1);
1664           return 0;
1665         }
1666
1667       /* #unassert with no answer is valid - it removes all answers.  */
1668       if (type == T_UNASSERT && paren->type == CPP_EOF)
1669         return 0;
1670
1671       cpp_error (pfile, DL_ERROR, "missing '(' after predicate");
1672       return 1;
1673     }
1674
1675   for (acount = 0;; acount++)
1676     {
1677       size_t room_needed;
1678       const cpp_token *token = cpp_get_token (pfile);
1679       cpp_token *dest;
1680
1681       if (token->type == CPP_CLOSE_PAREN)
1682         break;
1683
1684       if (token->type == CPP_EOF)
1685         {
1686           cpp_error (pfile, DL_ERROR, "missing ')' to complete answer");
1687           return 1;
1688         }
1689
1690       /* struct answer includes the space for one token.  */
1691       room_needed = (sizeof (struct answer) + acount * sizeof (cpp_token));
1692
1693       if (BUFF_ROOM (pfile->a_buff) < room_needed)
1694         _cpp_extend_buff (pfile, &pfile->a_buff, sizeof (struct answer));
1695
1696       dest = &((struct answer *) BUFF_FRONT (pfile->a_buff))->first[acount];
1697       *dest = *token;
1698
1699       /* Drop whitespace at start, for answer equivalence purposes.  */
1700       if (acount == 0)
1701         dest->flags &= ~PREV_WHITE;
1702     }
1703
1704   if (acount == 0)
1705     {
1706       cpp_error (pfile, DL_ERROR, "predicate's answer is empty");
1707       return 1;
1708     }
1709
1710   answer = (struct answer *) BUFF_FRONT (pfile->a_buff);
1711   answer->count = acount;
1712   answer->next = NULL;
1713   *answerp = answer;
1714
1715   return 0;
1716 }
1717
1718 /* Parses an assertion directive of type TYPE, returning a pointer to
1719    the hash node of the predicate, or 0 on error.  If an answer was
1720    supplied, it is placed in ANSWERP, otherwise it is set to 0.  */
1721 static cpp_hashnode *
1722 parse_assertion (pfile, answerp, type)
1723      cpp_reader *pfile;
1724      struct answer **answerp;
1725      int type;
1726 {
1727   cpp_hashnode *result = 0;
1728   const cpp_token *predicate;
1729
1730   /* We don't expand predicates or answers.  */
1731   pfile->state.prevent_expansion++;
1732
1733   *answerp = 0;
1734   predicate = cpp_get_token (pfile);
1735   if (predicate->type == CPP_EOF)
1736     cpp_error (pfile, DL_ERROR, "assertion without predicate");
1737   else if (predicate->type != CPP_NAME)
1738     cpp_error (pfile, DL_ERROR, "predicate must be an identifier");
1739   else if (parse_answer (pfile, answerp, type) == 0)
1740     {
1741       unsigned int len = NODE_LEN (predicate->val.node);
1742       unsigned char *sym = alloca (len + 1);
1743
1744       /* Prefix '#' to get it out of macro namespace.  */
1745       sym[0] = '#';
1746       memcpy (sym + 1, NODE_NAME (predicate->val.node), len);
1747       result = cpp_lookup (pfile, sym, len + 1);
1748     }
1749
1750   pfile->state.prevent_expansion--;
1751   return result;
1752 }
1753
1754 /* Returns a pointer to the pointer to CANDIDATE in the answer chain,
1755    or a pointer to NULL if the answer is not in the chain.  */
1756 static struct answer **
1757 find_answer (node, candidate)
1758      cpp_hashnode *node;
1759      const struct answer *candidate;
1760 {
1761   unsigned int i;
1762   struct answer **result;
1763
1764   for (result = &node->value.answers; *result; result = &(*result)->next)
1765     {
1766       struct answer *answer = *result;
1767
1768       if (answer->count == candidate->count)
1769         {
1770           for (i = 0; i < answer->count; i++)
1771             if (! _cpp_equiv_tokens (&answer->first[i], &candidate->first[i]))
1772               break;
1773
1774           if (i == answer->count)
1775             break;
1776         }
1777     }
1778
1779   return result;
1780 }
1781
1782 /* Test an assertion within a preprocessor conditional.  Returns
1783    nonzero on failure, zero on success.  On success, the result of
1784    the test is written into VALUE, otherwise the value 0.  */
1785 int
1786 _cpp_test_assertion (pfile, value)
1787      cpp_reader *pfile;
1788      unsigned int *value;
1789 {
1790   struct answer *answer;
1791   cpp_hashnode *node;
1792
1793   node = parse_assertion (pfile, &answer, T_IF);
1794
1795   /* For recovery, an erroneous assertion expression is handled as a
1796      failing assertion.  */
1797   *value = 0;
1798
1799   if (node)
1800     *value = (node->type == NT_ASSERTION &&
1801               (answer == 0 || *find_answer (node, answer) != 0));
1802   else if (pfile->cur_token[-1].type == CPP_EOF)
1803     _cpp_backup_tokens (pfile, 1);
1804
1805   /* We don't commit the memory for the answer - it's temporary only.  */
1806   return node == 0;
1807 }
1808
1809 /* Handle #assert.  */
1810 static void
1811 do_assert (pfile)
1812      cpp_reader *pfile;
1813 {
1814   struct answer *new_answer;
1815   cpp_hashnode *node;
1816
1817   node = parse_assertion (pfile, &new_answer, T_ASSERT);
1818   if (node)
1819     {
1820       /* Place the new answer in the answer list.  First check there
1821          is not a duplicate.  */
1822       new_answer->next = 0;
1823       if (node->type == NT_ASSERTION)
1824         {
1825           if (*find_answer (node, new_answer))
1826             {
1827               cpp_error (pfile, DL_WARNING, "\"%s\" re-asserted",
1828                          NODE_NAME (node) + 1);
1829               return;
1830             }
1831           new_answer->next = node->value.answers;
1832         }
1833
1834       node->type = NT_ASSERTION;
1835       node->value.answers = new_answer;
1836       BUFF_FRONT (pfile->a_buff) += (sizeof (struct answer)
1837                                      + (new_answer->count - 1)
1838                                      * sizeof (cpp_token));
1839       check_eol (pfile);
1840     }
1841 }
1842
1843 /* Handle #unassert.  */
1844 static void
1845 do_unassert (pfile)
1846      cpp_reader *pfile;
1847 {
1848   cpp_hashnode *node;
1849   struct answer *answer;
1850
1851   node = parse_assertion (pfile, &answer, T_UNASSERT);
1852   /* It isn't an error to #unassert something that isn't asserted.  */
1853   if (node && node->type == NT_ASSERTION)
1854     {
1855       if (answer)
1856         {
1857           struct answer **p = find_answer (node, answer), *temp;
1858
1859           /* Remove the answer from the list.  */
1860           temp = *p;
1861           if (temp)
1862             *p = temp->next;
1863
1864           /* Did we free the last answer?  */
1865           if (node->value.answers == 0)
1866             node->type = NT_VOID;
1867
1868           check_eol (pfile);
1869         }
1870       else
1871         _cpp_free_definition (node);
1872     }
1873
1874   /* We don't commit the memory for the answer - it's temporary only.  */
1875 }
1876
1877 /* These are for -D, -U, -A.  */
1878
1879 /* Process the string STR as if it appeared as the body of a #define.
1880    If STR is just an identifier, define it with value 1.
1881    If STR has anything after the identifier, then it should
1882    be identifier=definition.  */
1883 void
1884 cpp_define (pfile, str)
1885      cpp_reader *pfile;
1886      const char *str;
1887 {
1888   char *buf, *p;
1889   size_t count;
1890
1891   /* Copy the entire option so we can modify it.
1892      Change the first "=" in the string to a space.  If there is none,
1893      tack " 1" on the end.  */
1894
1895   count = strlen (str);
1896   buf = (char *) alloca (count + 3);
1897   memcpy (buf, str, count);
1898
1899   p = strchr (str, '=');
1900   if (p)
1901     buf[p - str] = ' ';
1902   else
1903     {
1904       buf[count++] = ' ';
1905       buf[count++] = '1';
1906     }
1907   buf[count] = '\0';
1908
1909   run_directive (pfile, T_DEFINE, buf, count);
1910 }
1911
1912 /* Slight variant of the above for use by initialize_builtins.  */
1913 void
1914 _cpp_define_builtin (pfile, str)
1915      cpp_reader *pfile;
1916      const char *str;
1917 {
1918   run_directive (pfile, T_DEFINE, str, strlen (str));
1919 }
1920
1921 /* Process MACRO as if it appeared as the body of an #undef.  */
1922 void
1923 cpp_undef (pfile, macro)
1924      cpp_reader *pfile;
1925      const char *macro;
1926 {
1927   run_directive (pfile, T_UNDEF, macro, strlen (macro));
1928 }
1929
1930 /* Process the string STR as if it appeared as the body of a #assert.  */
1931 void
1932 cpp_assert (pfile, str)
1933      cpp_reader *pfile;
1934      const char *str;
1935 {
1936   handle_assertion (pfile, str, T_ASSERT);
1937 }
1938
1939 /* Process STR as if it appeared as the body of an #unassert.  */
1940 void
1941 cpp_unassert (pfile, str)
1942      cpp_reader *pfile;
1943      const char *str;
1944 {
1945   handle_assertion (pfile, str, T_UNASSERT);
1946 }
1947
1948 /* Common code for cpp_assert (-A) and cpp_unassert (-A-).  */
1949 static void
1950 handle_assertion (pfile, str, type)
1951      cpp_reader *pfile;
1952      const char *str;
1953      int type;
1954 {
1955   size_t count = strlen (str);
1956   const char *p = strchr (str, '=');
1957
1958   if (p)
1959     {
1960       /* Copy the entire option so we can modify it.  Change the first
1961          "=" in the string to a '(', and tack a ')' on the end.  */
1962       char *buf = (char *) alloca (count + 2);
1963
1964       memcpy (buf, str, count);
1965       buf[p - str] = '(';
1966       buf[count++] = ')';
1967       buf[count] = '\0';
1968       str = buf;
1969     }
1970
1971   run_directive (pfile, type, str, count);
1972 }
1973
1974 /* The number of errors for a given reader.  */
1975 unsigned int
1976 cpp_errors (pfile)
1977      cpp_reader *pfile;
1978 {
1979   return pfile->errors;
1980 }
1981
1982 /* The options structure.  */
1983 cpp_options *
1984 cpp_get_options (pfile)
1985      cpp_reader *pfile;
1986 {
1987   return &pfile->opts;
1988 }
1989
1990 /* The callbacks structure.  */
1991 cpp_callbacks *
1992 cpp_get_callbacks (pfile)
1993      cpp_reader *pfile;
1994 {
1995   return &pfile->cb;
1996 }
1997
1998 /* The line map set.  */
1999 const struct line_maps *
2000 cpp_get_line_maps (pfile)
2001      cpp_reader *pfile;
2002 {
2003   return &pfile->line_maps;
2004 }
2005
2006 /* Copy the given callbacks structure to our own.  */
2007 void
2008 cpp_set_callbacks (pfile, cb)
2009      cpp_reader *pfile;
2010      cpp_callbacks *cb;
2011 {
2012   pfile->cb = *cb;
2013 }
2014
2015 /* Push a new buffer on the buffer stack.  Returns the new buffer; it
2016    doesn't fail.  It does not generate a file change call back; that
2017    is the responsibility of the caller.  */
2018 cpp_buffer *
2019 cpp_push_buffer (pfile, buffer, len, from_stage3, return_at_eof)
2020      cpp_reader *pfile;
2021      const uchar *buffer;
2022      size_t len;
2023      int from_stage3;
2024      int return_at_eof;
2025 {
2026   cpp_buffer *new = xobnew (&pfile->buffer_ob, cpp_buffer);
2027
2028   /* Clears, amongst other things, if_stack and mi_cmacro.  */
2029   memset (new, 0, sizeof (cpp_buffer));
2030
2031   new->line_base = new->buf = new->cur = buffer;
2032   new->rlimit = buffer + len;
2033   new->from_stage3 = from_stage3 || CPP_OPTION (pfile, traditional);
2034   new->prev = pfile->buffer;
2035   new->return_at_eof = return_at_eof;
2036   new->saved_flags = BOL;
2037
2038   pfile->buffer = new;
2039
2040   return new;
2041 }
2042
2043 /* Pops a single buffer, with a file change call-back if appropriate.
2044    Then pushes the next -include file, if any remain.  */
2045 void
2046 _cpp_pop_buffer (pfile)
2047      cpp_reader *pfile;
2048 {
2049   cpp_buffer *buffer = pfile->buffer;
2050   struct include_file *inc = buffer->inc;
2051   struct if_stack *ifs;
2052
2053   /* Walk back up the conditional stack till we reach its level at
2054      entry to this file, issuing error messages.  */
2055   for (ifs = buffer->if_stack; ifs; ifs = ifs->next)
2056     cpp_error_with_line (pfile, DL_ERROR, ifs->line, 0,
2057                          "unterminated #%s", dtable[ifs->type].name);
2058
2059   /* In case of a missing #endif.  */
2060   pfile->state.skipping = 0;
2061
2062   /* _cpp_do_file_change expects pfile->buffer to be the new one.  */
2063   pfile->buffer = buffer->prev;
2064
2065   /* Free the buffer object now; we may want to push a new buffer
2066      in _cpp_push_next_include_file.  */
2067   obstack_free (&pfile->buffer_ob, buffer);
2068
2069   if (inc)
2070     {
2071       _cpp_pop_file_buffer (pfile, inc);
2072
2073       /* Don't generate a callback for popping the main file.  */
2074       if (pfile->buffer)
2075         _cpp_do_file_change (pfile, LC_LEAVE, 0, 0, 0);
2076     }
2077 }
2078
2079 /* Enter all recognized directives in the hash table.  */
2080 void
2081 _cpp_init_directives (pfile)
2082      cpp_reader *pfile;
2083 {
2084   unsigned int i;
2085   cpp_hashnode *node;
2086
2087   for (i = 0; i < (unsigned int) N_DIRECTIVES; i++)
2088     {
2089       node = cpp_lookup (pfile, dtable[i].name, dtable[i].length);
2090       node->is_directive = 1;
2091       node->directive_index = i;
2092     }
2093 }