src/eregex.h

   1 /* Definitions for data structures and routines for the regular
   2    expression library, version 0.12.
   3    Copyright (C) 1985,1989-1993,1995-1998, 2000 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.  Its master source is NOT part of
   5    the C library, however.  The master source lives in /gd/gnu/lib.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #ifndef USE_INCLUDED_REGEX
  23 #include <regex.h>
  24 #else
  25 #ifndef _REGEX_H
  26 #define _REGEX_H 1
  27
  28 /* Allow the use in C++ code.  */
  29 #ifdef __cplusplus
  30 extern "C" {
  31 #endif
  32
  33 /* POSIX says that <sys/types.h> must be included (by the caller) before
  34    <regex.h>.  */
  35
  36 #if !defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE && defined VMS
  37 /* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
  38    should be there.  */
  39 # include <stddef.h>
  40 #endif
  41
  42 /* The following two types have to be signed and unsigned integer type
  43    wide enough to hold a value of a pointer.  For most ANSI compilers
  44    ptrdiff_t and size_t should be likely OK.  Still size of these two
  45    types is 2 for Microsoft C.  Ugh... */
  46 typedef long int s_reg_t;
  47 typedef unsigned long int active_reg_t;
  48
  49 /* The following bits are used to determine the regexp syntax we
  50    recognize.  The set/not-set meanings are chosen so that Emacs syntax
  51    remains the value 0.  The bits are given in alphabetical order, and
  52    the definitions shifted by one from the previous bit; thus, when we
  53    add or remove a bit, only one other definition need change.  */
  54 typedef unsigned long int reg_syntax_t;
  55
  56 /* If this bit is not set, then \ inside a bracket expression is literal.
  57    If set, then such a \ quotes the following character.  */
  58 #define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
  59
  60 /* If this bit is not set, then + and ? are operators, and \+ and \? are
  61      literals.
  62    If set, then \+ and \? are operators and + and ? are literals.  */
  63 #define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
  64
  65 /* If this bit is set, then character classes are supported.  They are:
  66      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
  67      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
  68    If not set, then character classes are not supported.  */
  69 #define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
  70
  71 /* If this bit is set, then ^ and $ are always anchors (outside bracket
  72      expressions, of course).
  73    If this bit is not set, then it depends:
  74         ^  is an anchor if it is at the beginning of a regular
  75            expression or after an open-group or an alternation operator;
  76         $  is an anchor if it is at the end of a regular expression, or
  77            before a close-group or an alternation operator.
  78
  79    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
  80    POSIX draft 11.2 says that * etc. in leading positions is undefined.
  81    We already implemented a previous draft which made those constructs
  82    invalid, though, so we haven't changed the code back.  */
  83 #define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
  84
  85 /* If this bit is set, then special characters are always special
  86      regardless of where they are in the pattern.
  87    If this bit is not set, then special characters are special only in
  88      some contexts; otherwise they are ordinary.  Specifically,
  89      * + ? and intervals are only special when not after the beginning,
  90      open-group, or alternation operator.  */
  91 #define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
  92
  93 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
  94      immediately after an alternation or begin-group operator.  */
  95 #define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
  96
  97 /* If this bit is set, then . matches newline.
  98    If not set, then it doesn't.  */
  99 #define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
 100
 101 /* If this bit is set, then . doesn't match NUL.
 102    If not set, then it does.  */
 103 #define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
 104
 105 /* If this bit is set, nonmatching lists [^...] do not match newline.
 106    If not set, they do.  */
 107 #define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
 108
 109 /* If this bit is set, either \{...\} or {...} defines an
 110      interval, depending on RE_NO_BK_BRACES.
 111    If not set, \{, \}, {, and } are literals.  */
 112 #define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
 113
 114 /* If this bit is set, +, ? and | aren't recognized as operators.
 115    If not set, they are.  */
 116 #define RE_LIMITED_OPS (RE_INTERVALS << 1)
 117
 118 /* If this bit is set, newline is an alternation operator.
 119    If not set, newline is literal.  */
 120 #define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
 121
 122 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
 123      are literals.
 124   If not set, then `\{...\}' defines an interval.  */
 125 #define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
 126
 127 /* If this bit is set, (...) defines a group, and \( and \) are literals.
 128    If not set, \(...\) defines a group, and ( and ) are literals.  */
 129 #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
 130
 131 /* If this bit is set, then \<digit> matches <digit>.
 132    If not set, then \<digit> is a back-reference.  */
 133 #define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
 134
 135 /* If this bit is set, then | is an alternation operator, and \| is literal.
 136    If not set, then \| is an alternation operator, and | is literal.  */
 137 #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
 138
 139 /* If this bit is set, then an ending range point collating higher
 140      than the starting range point, as in [z-a], is invalid.
 141    If not set, then when ending range point collates higher than the
 142      starting range point, the range is ignored.  */
 143 #define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
 144
 145 /* If this bit is set, then an unmatched ) is ordinary.
 146    If not set, then an unmatched ) is invalid.  */
 147 #define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
 148
 149 /* If this bit is set, succeed as soon as we match the whole pattern,
 150    without further backtracking.  */
 151 #define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
 152
 153 /* If this bit is set, do not process the GNU regex operators.
 154    If not set, then the GNU regex operators are recognized. */
 155 #define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
 156
 157 /* If this bit is set, turn on internal regex debugging.
 158    If not set, and debugging was on, turn it off.
 159    This only works if regex.c is compiled -DDEBUG.
 160    We define this bit always, so that all that's needed to turn on
 161    debugging is to recompile regex.c; the calling code can always have
 162    this bit set, and it won't affect anything in the normal case. */
 163 #define RE_DEBUG (RE_NO_GNU_OPS << 1)
 164
 165 /* If this bit is set, a syntactically invalid interval is treated as
 166    a string of ordinary characters.  For example, the ERE 'a{1' is
 167    treated as 'a\{1'.  */
 168 #define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
 169
 170 /* This global variable defines the particular regexp syntax to use (for
 171    some interfaces).  When a regexp is compiled, the syntax used is
 172    stored in the pattern buffer, so changing this does not affect
 173    already-compiled regexps.  */
 174 extern reg_syntax_t re_syntax_options;
 175 \f
 176 /* Define combinations of the above bits for the standard possibilities.
 177    (The [[[ comments delimit what gets put into the Texinfo file, so
 178    don't delete them!)  */
 179 /* [[[begin syntaxes]]] */
 180 #define RE_SYNTAX_EMACS 0
 181
 182 #define RE_SYNTAX_AWK                                                   \
 183   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                     \
 184    | RE_NO_BK_PARENS              | RE_NO_BK_REFS                       \
 185    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                  \
 186    | RE_DOT_NEWLINE               | RE_CONTEXT_INDEP_ANCHORS            \
 187    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
 188
 189 #define RE_SYNTAX_GNU_AWK                                               \
 190   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG) \
 191    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS))
 192
 193 #define RE_SYNTAX_POSIX_AWK                                             \
 194   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS              \
 195    | RE_INTERVALS           | RE_NO_GNU_OPS)
 196
 197 #define RE_SYNTAX_GREP                                                  \
 198   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
 199    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
 200    | RE_NEWLINE_ALT)
 201
 202 #define RE_SYNTAX_EGREP                                                 \
 203   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
 204    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
 205    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
 206    | RE_NO_BK_VBAR)
 207
 208 #define RE_SYNTAX_POSIX_EGREP                                           \
 209   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES                     \
 210    | RE_INVALID_INTERVAL_ORD)
 211
 212 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
 213 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
 214
 215 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
 216
 217 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
 218 #define _RE_SYNTAX_POSIX_COMMON                                         \
 219   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
 220    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
 221
 222 #define RE_SYNTAX_POSIX_BASIC                                           \
 223   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
 224
 225 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
 226    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
 227    isn't minimal, since other operators, such as \`, aren't disabled.  */
 228 #define RE_SYNTAX_POSIX_MINIMAL_BASIC                                   \
 229   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
 230
 231 #define RE_SYNTAX_POSIX_EXTENDED                                        \
 232   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 233    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                           \
 234    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                             \
 235    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
 236
 237 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
 238    removed and RE_NO_BK_REFS is added.  */
 239 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                                \
 240   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 241    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
 242    | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
 243    | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)
 244 /* [[[end syntaxes]]] */
 245 \f
 246 /* Maximum number of duplicates an interval can allow.  Some systems
 247    (erroneously) define this in other header files, but we want our
 248    value, so remove any previous define.  */
 249 #ifdef RE_DUP_MAX
 250 # undef RE_DUP_MAX
 251 #endif
 252 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
 253 #define RE_DUP_MAX (0x7fff)
 254
 255
 256 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
 257
 258 /* If this bit is set, then use extended regular expression syntax.
 259    If not set, then use basic regular expression syntax.  */
 260 #define REG_EXTENDED 1
 261
 262 /* If this bit is set, then ignore case when matching.
 263    If not set, then case is significant.  */
 264 #define REG_ICASE (REG_EXTENDED << 1)
 265
 266 /* If this bit is set, then anchors do not match at newline
 267      characters in the string.
 268    If not set, then anchors do match at newlines.  */
 269 #define REG_NEWLINE (REG_ICASE << 1)
 270
 271 /* If this bit is set, then report only success or fail in regexec.
 272    If not set, then returns differ between not matching and errors.  */
 273 #define REG_NOSUB (REG_NEWLINE << 1)
 274
 275
 276 /* POSIX `eflags' bits (i.e., information for regexec).  */
 277
 278 /* If this bit is set, then the beginning-of-line operator doesn't match
 279      the beginning of the string (presumably because it's not the
 280      beginning of a line).
 281    If not set, then the beginning-of-line operator does match the
 282      beginning of the string.  */
 283 #define REG_NOTBOL 1
 284
 285 /* Like REG_NOTBOL, except for the end-of-line.  */
 286 #define REG_NOTEOL (1 << 1)
 287
 288
 289 /* If any error codes are removed, changed, or added, update the
 290    `re_error_msg' table in regex.c.  */
 291 typedef enum
 292 {
 293 #ifdef _XOPEN_SOURCE
 294   REG_ENOSYS = -1,      /* This will never happen for this implementation.  */
 295 #endif
 296
 297   REG_NOERROR = 0,      /* Success.  */
 298   REG_NOMATCH,          /* Didn't find a match (for regexec).  */
 299
 300   /* POSIX regcomp return error codes.  (In the order listed in the
 301      standard.)  */
 302   REG_BADPAT,           /* Invalid pattern.  */
 303   REG_ECOLLATE,         /* Not implemented.  */
 304   REG_ECTYPE,           /* Invalid character class name.  */
 305   REG_EESCAPE,          /* Trailing backslash.  */
 306   REG_ESUBREG,          /* Invalid back reference.  */
 307   REG_EBRACK,           /* Unmatched left bracket.  */
 308   REG_EPAREN,           /* Parenthesis imbalance.  */
 309   REG_EBRACE,           /* Unmatched \{.  */
 310   REG_BADBR,            /* Invalid contents of \{\}.  */
 311   REG_ERANGE,           /* Invalid range end.  */
 312   REG_ESPACE,           /* Ran out of memory.  */
 313   REG_BADRPT,           /* No preceding re for repetition op.  */
 314
 315   /* Error codes we've added.  */
 316   REG_EEND,             /* Premature end.  */
 317   REG_ESIZE,            /* Compiled pattern bigger than 2^16 bytes.  */
 318   REG_ERPAREN           /* Unmatched ) or \); not returned from regcomp.  */
 319 } reg_errcode_t;
 320 \f
 321 /* This data structure represents a compiled pattern.  Before calling
 322    the pattern compiler, the fields `buffer', `allocated', `fastmap',
 323    `translate', and `no_sub' can be set.  After the pattern has been
 324    compiled, the `re_nsub' field is available.  All other fields are
 325    private to the regex routines.  */
 326
 327 #ifndef RE_TRANSLATE_TYPE
 328 # define RE_TRANSLATE_TYPE char *
 329 #endif
 330
 331 struct re_pattern_buffer
 332 {
 333 /* [[[begin pattern_buffer]]] */
 334         /* Space that holds the compiled pattern.  It is declared as
 335           `unsigned char *' because its elements are
 336            sometimes used as array indexes.  */
 337   unsigned char *buffer;
 338
 339         /* Number of bytes to which `buffer' points.  */
 340   unsigned long int allocated;
 341
 342         /* Number of bytes actually used in `buffer'.  */
 343   unsigned long int used;
 344
 345         /* Syntax setting with which the pattern was compiled.  */
 346   reg_syntax_t syntax;
 347
 348         /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
 349            the fastmap, if there is one, to skip over impossible
 350            starting points for matches.  */
 351   char *fastmap;
 352
 353         /* Either a translate table to apply to all characters before
 354            comparing them, or zero for no translation.  The translation
 355            is applied to a pattern when it is compiled and to a string
 356            when it is matched.  */
 357   RE_TRANSLATE_TYPE translate;
 358
 359         /* Number of subexpressions found by the compiler.  */
 360   size_t re_nsub;
 361
 362         /* Zero if this pattern cannot match the empty string, one else.
 363            Well, in truth it's used only in `re_search_2', to see
 364            whether or not we should use the fastmap, so we don't set
 365            this absolutely perfectly; see `re_compile_fastmap' (the
 366            `duplicate' case).  */
 367   unsigned can_be_null : 1;
 368
 369         /* If REGS_UNALLOCATED, allocate space in the `regs' structure
 370              for `max (RE_NREGS, re_nsub + 1)' groups.
 371            If REGS_REALLOCATE, reallocate space if necessary.
 372            If REGS_FIXED, use what's there.  */
 373 #define REGS_UNALLOCATED 0
 374 #define REGS_REALLOCATE 1
 375 #define REGS_FIXED 2
 376   unsigned regs_allocated : 2;
 377
 378         /* Set to zero when `regex_compile' compiles a pattern; set to one
 379            by `re_compile_fastmap' if it updates the fastmap.  */
 380   unsigned fastmap_accurate : 1;
 381
 382         /* If set, `re_match_2' does not return information about
 383            subexpressions.  */
 384   unsigned no_sub : 1;
 385
 386         /* If set, a beginning-of-line anchor doesn't match at the
 387            beginning of the string.  */
 388   unsigned not_bol : 1;
 389
 390         /* Similarly for an end-of-line anchor.  */
 391   unsigned not_eol : 1;
 392
 393         /* If true, an anchor at a newline matches.  */
 394   unsigned newline_anchor : 1;
 395
 396 /* [[[end pattern_buffer]]] */
 397 };
 398
 399 typedef struct re_pattern_buffer regex_t;
 400 \f
 401 /* Type for byte offsets within the string.  POSIX mandates this.  */
 402 typedef int regoff_t;
 403
 404
 405 /* This is the structure we store register match data in.  See
 406    regex.texinfo for a full description of what registers match.  */
 407 struct re_registers
 408 {
 409   unsigned num_regs;
 410   regoff_t *start;
 411   regoff_t *end;
 412 };
 413
 414
 415 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
 416    `re_match_2' returns information about at least this many registers
 417    the first time a `regs' structure is passed.  */
 418 #ifndef RE_NREGS
 419 # define RE_NREGS 30
 420 #endif
 421
 422
 423 /* POSIX specification for registers.  Aside from the different names than
 424    `re_registers', POSIX uses an array of structures, instead of a
 425    structure of arrays.  */
 426 typedef struct
 427 {
 428   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
 429   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
 430 } regmatch_t;
 431 \f
 432 /* Declarations for routines.  */
 433
 434 /* To avoid duplicating every routine declaration -- once with a
 435    prototype (if we are ANSI), and once without (if we aren't) -- we
 436    use the following macro to declare argument types.  This
 437    unfortunately clutters up the declarations a bit, but I think it's
 438    worth it.  */
 439
 440 #if __STDC__
 441
 442 # define _RE_ARGS(args) args
 443
 444 #else /* not __STDC__ */
 445
 446 # define _RE_ARGS(args) ()
 447
 448 #endif /* not __STDC__ */
 449
 450 /* Sets the current default syntax to SYNTAX, and return the old syntax.
 451    You can also simply assign to the `re_syntax_options' variable.  */
 452 extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
 453
 454 /* Compile the regular expression PATTERN, with length LENGTH
 455    and syntax given by the global `re_syntax_options', into the buffer
 456    BUFFER.  Return NULL if successful, and an error string if not.  */
 457 extern const char *re_compile_pattern
 458   _RE_ARGS ((const char *pattern, size_t length,
 459              struct re_pattern_buffer *buffer));
 460
 461
 462 /* Compile a fastmap for the compiled pattern in BUFFER; used to
 463    accelerate searches.  Return 0 if successful and -2 if was an
 464    internal error.  */
 465 extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
 466
 467
 468 /* Search in the string STRING (with length LENGTH) for the pattern
 469    compiled into BUFFER.  Start searching at position START, for RANGE
 470    characters.  Return the starting position of the match, -1 for no
 471    match, or -2 for an internal error.  Also return register
 472    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
 473 extern int re_search
 474   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 475             int length, int start, int range, struct re_registers *regs));
 476
 477
 478 /* Like `re_search', but search in the concatenation of STRING1 and
 479    STRING2.  Also, stop searching at index START + STOP.  */
 480 extern int re_search_2
 481   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 482              int length1, const char *string2, int length2,
 483              int start, int range, struct re_registers *regs, int stop));
 484
 485
 486 /* Like `re_search', but return how many characters in STRING the regexp
 487    in BUFFER matched, starting at position START.  */
 488 extern int re_match
 489   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 490              int length, int start, struct re_registers *regs));
 491
 492
 493 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
 494 extern int re_match_2
 495   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 496              int length1, const char *string2, int length2,
 497              int start, struct re_registers *regs, int stop));
 498
 499
 500 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
 501    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
 502    for recording register information.  STARTS and ENDS must be
 503    allocated with malloc, and must each be at least `NUM_REGS * sizeof
 504    (regoff_t)' bytes long.
 505
 506    If NUM_REGS == 0, then subsequent matches should allocate their own
 507    register data.
 508
 509    Unless this function is called, the first search or match using
 510    PATTERN_BUFFER will allocate its own register data, without
 511    freeing the old data.  */
 512 extern void re_set_registers
 513   _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
 514              unsigned num_regs, regoff_t *starts, regoff_t *ends));
 515
 516 #if defined _REGEX_RE_COMP || defined _LIBC
 517 # ifndef _CRAY
 518 /* 4.2 bsd compatibility.  */
 519 extern char *re_comp _RE_ARGS ((const char *));
 520 extern int re_exec _RE_ARGS ((const char *));
 521 # endif
 522 #endif
 523
 524 /* GCC 2.95 and later have "__restrict"; C99 compilers have
 525    "restrict", and "configure" may have defined "restrict".  */
 526 #ifndef __restrict
 527 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
 528 #  if defined restrict || 199901L <= __STDC_VERSION__
 529 #   define __restrict restrict
 530 #  else
 531 #   define __restrict
 532 #  endif
 533 # endif
 534 #endif
 535 /* For now unconditionally define __restrict_arr to expand to nothing.
 536    Ideally we would have a test for the compiler which allows defining
 537    it to restrict.  */
 538 #define __restrict_arr
 539
 540 /* POSIX compatibility.  */
 541 extern int regcomp _RE_ARGS ((regex_t *__restrict __preg,
 542                               const char *__restrict __pattern,
 543                               int __cflags));
 544
 545 extern int regexec _RE_ARGS ((const regex_t *__restrict __preg,
 546                               const char *__restrict __string, size_t __nmatch,
 547                               regmatch_t __pmatch[__restrict_arr],
 548                               int __eflags));
 549
 550 extern size_t regerror _RE_ARGS ((int __errcode, const regex_t *__preg,
 551                                   char *__errbuf, size_t __errbuf_size));
 552
 553 extern void regfree _RE_ARGS ((regex_t *__preg));
 554
 555
 556 #ifdef __cplusplus
 557 }
 558 #endif  /* C++ */
 559
 560 #endif /* regex.h */
 561 \f
 562 /*
 563 Local variables:
 564 make-backup-files: t
 565 version-control: t
 566 trim-versions-without-asking: nil
 567 End:
 568 */
 569 #endif