include/xregex2.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
   5    This file is part of the GNU C Library.  Its master source is NOT part of
   6    the C library, however.  The master source lives in /gd/gnu/lib.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Library General Public License as
  10    published by the Free Software Foundation; either version 2 of the
  11    License, or (at your option) any later version.
  12
  13    The GNU C Library 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 GNU
  16    Library General Public License for more details.
  17
  18    You should have received a copy of the GNU Library General Public
  19    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  20    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #ifndef _REGEX_H
  24 #define _REGEX_H 1
  25
  26 /* Allow the use in C++ code.  */
  27 #ifdef __cplusplus
  28 extern "C" {
  29 #endif
  30
  31 /* POSIX says that <sys/types.h> must be included (by the caller) before
  32    <regex.h>.  */
  33
  34 #if !defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE && defined VMS
  35 /* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
  36    should be there.  */
  37 # include <stddef.h>
  38 #endif
  39
  40 /* The following two types have to be signed and unsigned integer type
  41    wide enough to hold a value of a pointer.  For most ANSI compilers
  42    ptrdiff_t and size_t should be likely OK.  Still size of these two
  43    types is 2 for Microsoft C.  Ugh... */
  44 typedef long int s_reg_t;
  45 typedef unsigned long int active_reg_t;
  46
  47 /* The following bits are used to determine the regexp syntax we
  48    recognize.  The set/not-set meanings are chosen so that Emacs syntax
  49    remains the value 0.  The bits are given in alphabetical order, and
  50    the definitions shifted by one from the previous bit; thus, when we
  51    add or remove a bit, only one other definition need change.  */
  52 typedef unsigned long int reg_syntax_t;
  53
  54 /* If this bit is not set, then \ inside a bracket expression is literal.
  55    If set, then such a \ quotes the following character.  */
  56 #define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
  57
  58 /* If this bit is not set, then + and ? are operators, and \+ and \? are
  59      literals.
  60    If set, then \+ and \? are operators and + and ? are literals.  */
  61 #define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
  62
  63 /* If this bit is set, then character classes are supported.  They are:
  64      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
  65      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
  66    If not set, then character classes are not supported.  */
  67 #define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
  68
  69 /* If this bit is set, then ^ and $ are always anchors (outside bracket
  70      expressions, of course).
  71    If this bit is not set, then it depends:
  72         ^  is an anchor if it is at the beginning of a regular
  73            expression or after an open-group or an alternation operator;
  74         $  is an anchor if it is at the end of a regular expression, or
  75            before a close-group or an alternation operator.
  76
  77    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
  78    POSIX draft 11.2 says that * etc. in leading positions is undefined.
  79    We already implemented a previous draft which made those constructs
  80    invalid, though, so we haven't changed the code back.  */
  81 #define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
  82
  83 /* If this bit is set, then special characters are always special
  84      regardless of where they are in the pattern.
  85    If this bit is not set, then special characters are special only in
  86      some contexts; otherwise they are ordinary.  Specifically,
  87      * + ? and intervals are only special when not after the beginning,
  88      open-group, or alternation operator.  */
  89 #define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
  90
  91 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
  92      immediately after an alternation or begin-group operator.  */
  93 #define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
  94
  95 /* If this bit is set, then . matches newline.
  96    If not set, then it doesn't.  */
  97 #define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
  98
  99 /* If this bit is set, then . doesn't match NUL.
 100    If not set, then it does.  */
 101 #define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
 102
 103 /* If this bit is set, nonmatching lists [^...] do not match newline.
 104    If not set, they do.  */
 105 #define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
 106
 107 /* If this bit is set, either \{...\} or {...} defines an
 108      interval, depending on RE_NO_BK_BRACES.
 109    If not set, \{, \}, {, and } are literals.  */
 110 #define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
 111
 112 /* If this bit is set, +, ? and | aren't recognized as operators.
 113    If not set, they are.  */
 114 #define RE_LIMITED_OPS (RE_INTERVALS << 1)
 115
 116 /* If this bit is set, newline is an alternation operator.
 117    If not set, newline is literal.  */
 118 #define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
 119
 120 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
 121      are literals.
 122   If not set, then `\{...\}' defines an interval.  */
 123 #define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
 124
 125 /* If this bit is set, (...) defines a group, and \( and \) are literals.
 126    If not set, \(...\) defines a group, and ( and ) are literals.  */
 127 #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
 128
 129 /* If this bit is set, then \<digit> matches <digit>.
 130    If not set, then \<digit> is a back-reference.  */
 131 #define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
 132
 133 /* If this bit is set, then | is an alternation operator, and \| is literal.
 134    If not set, then \| is an alternation operator, and | is literal.  */
 135 #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
 136
 137 /* If this bit is set, then an ending range point collating higher
 138      than the starting range point, as in [z-a], is invalid.
 139    If not set, then when ending range point collates higher than the
 140      starting range point, the range is ignored.  */
 141 #define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
 142
 143 /* If this bit is set, then an unmatched ) is ordinary.
 144    If not set, then an unmatched ) is invalid.  */
 145 #define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
 146
 147 /* If this bit is set, succeed as soon as we match the whole pattern,
 148    without further backtracking.  */
 149 #define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
 150
 151 /* If this bit is set, do not process the GNU regex operators.
 152    If not set, then the GNU regex operators are recognized. */
 153 #define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
 154
 155 /* If this bit is set, turn on internal regex debugging.
 156    If not set, and debugging was on, turn it off.
 157    This only works if regex.c is compiled -DDEBUG.
 158    We define this bit always, so that all that's needed to turn on
 159    debugging is to recompile regex.c; the calling code can always have
 160    this bit set, and it won't affect anything in the normal case. */
 161 #define RE_DEBUG (RE_NO_GNU_OPS << 1)
 162
 163 /* If this bit is set, a syntactically invalid interval is treated as
 164    a string of ordinary characters.  For example, the ERE 'a{1' is
 165    treated as 'a\{1'.  */
 166 #define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
 167
 168 /* This global variable defines the particular regexp syntax to use (for
 169    some interfaces).  When a regexp is compiled, the syntax used is
 170    stored in the pattern buffer, so changing this does not affect
 171    already-compiled regexps.  */
 172 extern reg_syntax_t re_syntax_options;
 173 \f
 174 /* Define combinations of the above bits for the standard possibilities.
 175    (The [[[ comments delimit what gets put into the Texinfo file, so
 176    don't delete them!)  */
 177 /* [[[begin syntaxes]]] */
 178 #define RE_SYNTAX_EMACS 0
 179
 180 #define RE_SYNTAX_AWK                                                   \
 181   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                     \
 182    | RE_NO_BK_PARENS              | RE_NO_BK_REFS                       \
 183    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                  \
 184    | RE_DOT_NEWLINE               | RE_CONTEXT_INDEP_ANCHORS            \
 185    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
 186
 187 #define RE_SYNTAX_GNU_AWK                                               \
 188   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG) \
 189    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS))
 190
 191 #define RE_SYNTAX_POSIX_AWK                                             \
 192   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS              \
 193    | RE_INTERVALS           | RE_NO_GNU_OPS)
 194
 195 #define RE_SYNTAX_GREP                                                  \
 196   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
 197    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
 198    | RE_NEWLINE_ALT)
 199
 200 #define RE_SYNTAX_EGREP                                                 \
 201   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
 202    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
 203    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
 204    | RE_NO_BK_VBAR)
 205
 206 #define RE_SYNTAX_POSIX_EGREP                                           \
 207   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES                     \
 208    | RE_INVALID_INTERVAL_ORD)
 209
 210 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
 211 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
 212
 213 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
 214
 215 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
 216 #define _RE_SYNTAX_POSIX_COMMON                                         \
 217   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
 218    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
 219
 220 #define RE_SYNTAX_POSIX_BASIC                                           \
 221   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
 222
 223 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
 224    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
 225    isn't minimal, since other operators, such as \`, aren't disabled.  */
 226 #define RE_SYNTAX_POSIX_MINIMAL_BASIC                                   \
 227   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
 228
 229 #define RE_SYNTAX_POSIX_EXTENDED                                        \
 230   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 231    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                           \
 232    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                             \
 233    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
 234
 235 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
 236    removed and RE_NO_BK_REFS is added.  */
 237 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                                \
 238   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 239    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
 240    | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
 241    | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)
 242 /* [[[end syntaxes]]] */
 243 \f
 244 /* Maximum number of duplicates an interval can allow.  Some systems
 245    (erroneously) define this in other header files, but we want our
 246    value, so remove any previous define.  */
 247 #ifdef RE_DUP_MAX
 248 # undef RE_DUP_MAX
 249 #endif
 250 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
 251 #define RE_DUP_MAX (0x7fff)
 252
 253
 254 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
 255
 256 /* If this bit is set, then use extended regular expression syntax.
 257    If not set, then use basic regular expression syntax.  */
 258 #define REG_EXTENDED 1
 259
 260 /* If this bit is set, then ignore case when matching.
 261    If not set, then case is significant.  */
 262 #define REG_ICASE (REG_EXTENDED << 1)
 263
 264 /* If this bit is set, then anchors do not match at newline
 265      characters in the string.
 266    If not set, then anchors do match at newlines.  */
 267 #define REG_NEWLINE (REG_ICASE << 1)
 268
 269 /* If this bit is set, then report only success or fail in regexec.
 270    If not set, then returns differ between not matching and errors.  */
 271 #define REG_NOSUB (REG_NEWLINE << 1)
 272
 273
 274 /* POSIX `eflags' bits (i.e., information for regexec).  */
 275
 276 /* If this bit is set, then the beginning-of-line operator doesn't match
 277      the beginning of the string (presumably because it's not the
 278      beginning of a line).
 279    If not set, then the beginning-of-line operator does match the
 280      beginning of the string.  */
 281 #define REG_NOTBOL 1
 282
 283 /* Like REG_NOTBOL, except for the end-of-line.  */
 284 #define REG_NOTEOL (1 << 1)
 285
 286
 287 /* If any error codes are removed, changed, or added, update the
 288    `re_error_msg' table in regex.c.  */
 289 typedef enum
 290 {
 291 #ifdef _XOPEN_SOURCE
 292   REG_ENOSYS = -1,      /* This will never happen for this implementation.  */
 293 #endif
 294
 295   REG_NOERROR = 0,      /* Success.  */
 296   REG_NOMATCH,          /* Didn't find a match (for regexec).  */
 297
 298   /* POSIX regcomp return error codes.  (In the order listed in the
 299      standard.)  */
 300   REG_BADPAT,           /* Invalid pattern.  */
 301   REG_ECOLLATE,         /* Not implemented.  */
 302   REG_ECTYPE,           /* Invalid character class name.  */
 303   REG_EESCAPE,          /* Trailing backslash.  */
 304   REG_ESUBREG,          /* Invalid back reference.  */
 305   REG_EBRACK,           /* Unmatched left bracket.  */
 306   REG_EPAREN,           /* Parenthesis imbalance.  */
 307   REG_EBRACE,           /* Unmatched \{.  */
 308   REG_BADBR,            /* Invalid contents of \{\}.  */
 309   REG_ERANGE,           /* Invalid range end.  */
 310   REG_ESPACE,           /* Ran out of memory.  */
 311   REG_BADRPT,           /* No preceding re for repetition op.  */
 312
 313   /* Error codes we've added.  */
 314   REG_EEND,             /* Premature end.  */
 315   REG_ESIZE,            /* Compiled pattern bigger than 2^16 bytes.  */
 316   REG_ERPAREN           /* Unmatched ) or \); not returned from regcomp.  */
 317 } reg_errcode_t;
 318 \f
 319 /* This data structure represents a compiled pattern.  Before calling
 320    the pattern compiler, the fields `buffer', `allocated', `fastmap',
 321    `translate', and `no_sub' can be set.  After the pattern has been
 322    compiled, the `re_nsub' field is available.  All other fields are
 323    private to the regex routines.  */
 324
 325 #ifndef RE_TRANSLATE_TYPE
 326 # define RE_TRANSLATE_TYPE char *
 327 #endif
 328
 329 struct re_pattern_buffer
 330 {
 331 /* [[[begin pattern_buffer]]] */
 332         /* Space that holds the compiled pattern.  It is declared as
 333           `unsigned char *' because its elements are
 334            sometimes used as array indexes.  */
 335   unsigned char *buffer;
 336
 337         /* Number of bytes to which `buffer' points.  */
 338   unsigned long int allocated;
 339
 340         /* Number of bytes actually used in `buffer'.  */
 341   unsigned long int used;
 342
 343         /* Syntax setting with which the pattern was compiled.  */
 344   reg_syntax_t syntax;
 345
 346         /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
 347            the fastmap, if there is one, to skip over impossible
 348            starting points for matches.  */
 349   char *fastmap;
 350
 351         /* Either a translate table to apply to all characters before
 352            comparing them, or zero for no translation.  The translation
 353            is applied to a pattern when it is compiled and to a string
 354            when it is matched.  */
 355   RE_TRANSLATE_TYPE translate;
 356
 357         /* Number of subexpressions found by the compiler.  */
 358   size_t re_nsub;
 359
 360         /* Zero if this pattern cannot match the empty string, one else.
 361            Well, in truth it's used only in `re_search_2', to see
 362            whether or not we should use the fastmap, so we don't set
 363            this absolutely perfectly; see `re_compile_fastmap' (the
 364            `duplicate' case).  */
 365   unsigned can_be_null : 1;
 366
 367         /* If REGS_UNALLOCATED, allocate space in the `regs' structure
 368              for `max (RE_NREGS, re_nsub + 1)' groups.
 369            If REGS_REALLOCATE, reallocate space if necessary.
 370            If REGS_FIXED, use what's there.  */
 371 #define REGS_UNALLOCATED 0
 372 #define REGS_REALLOCATE 1
 373 #define REGS_FIXED 2
 374   unsigned regs_allocated : 2;
 375
 376         /* Set to zero when `regex_compile' compiles a pattern; set to one
 377            by `re_compile_fastmap' if it updates the fastmap.  */
 378   unsigned fastmap_accurate : 1;
 379
 380         /* If set, `re_match_2' does not return information about
 381            subexpressions.  */
 382   unsigned no_sub : 1;
 383
 384         /* If set, a beginning-of-line anchor doesn't match at the
 385            beginning of the string.  */
 386   unsigned not_bol : 1;
 387
 388         /* Similarly for an end-of-line anchor.  */
 389   unsigned not_eol : 1;
 390
 391         /* If true, an anchor at a newline matches.  */
 392   unsigned newline_anchor : 1;
 393
 394 /* [[[end pattern_buffer]]] */
 395 };
 396
 397 typedef struct re_pattern_buffer regex_t;
 398 \f
 399 /* Type for byte offsets within the string.  POSIX mandates this.  */
 400 typedef int regoff_t;
 401
 402
 403 /* This is the structure we store register match data in.  See
 404    regex.texinfo for a full description of what registers match.  */
 405 struct re_registers
 406 {
 407   unsigned num_regs;
 408   regoff_t *start;
 409   regoff_t *end;
 410 };
 411
 412
 413 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
 414    `re_match_2' returns information about at least this many registers
 415    the first time a `regs' structure is passed.  */
 416 #ifndef RE_NREGS
 417 # define RE_NREGS 30
 418 #endif
 419
 420
 421 /* POSIX specification for registers.  Aside from the different names than
 422    `re_registers', POSIX uses an array of structures, instead of a
 423    structure of arrays.  */
 424 typedef struct
 425 {
 426   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
 427   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
 428 } regmatch_t;
 429 \f
 430 /* Declarations for routines.  */
 431
 432 /* To avoid duplicating every routine declaration -- once with a
 433    prototype (if we are ANSI), and once without (if we aren't) -- we
 434    use the following macro to declare argument types.  This
 435    unfortunately clutters up the declarations a bit, but I think it's
 436    worth it.  */
 437
 438 #if __STDC__
 439
 440 # define _RE_ARGS(args) args
 441
 442 #else /* not __STDC__ */
 443
 444 # define _RE_ARGS(args) ()
 445
 446 #endif /* not __STDC__ */
 447
 448 /* Sets the current default syntax to SYNTAX, and return the old syntax.
 449    You can also simply assign to the `re_syntax_options' variable.  */
 450 extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
 451
 452 /* Compile the regular expression PATTERN, with length LENGTH
 453    and syntax given by the global `re_syntax_options', into the buffer
 454    BUFFER.  Return NULL if successful, and an error string if not.  */
 455 extern const char *re_compile_pattern
 456   _RE_ARGS ((const char *pattern, size_t length,
 457              struct re_pattern_buffer *buffer));
 458
 459
 460 /* Compile a fastmap for the compiled pattern in BUFFER; used to
 461    accelerate searches.  Return 0 if successful and -2 if was an
 462    internal error.  */
 463 extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
 464
 465
 466 /* Search in the string STRING (with length LENGTH) for the pattern
 467    compiled into BUFFER.  Start searching at position START, for RANGE
 468    characters.  Return the starting position of the match, -1 for no
 469    match, or -2 for an internal error.  Also return register
 470    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
 471 extern int re_search
 472   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 473             int length, int start, int range, struct re_registers *regs));
 474
 475
 476 /* Like `re_search', but search in the concatenation of STRING1 and
 477    STRING2.  Also, stop searching at index START + STOP.  */
 478 extern int re_search_2
 479   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 480              int length1, const char *string2, int length2,
 481              int start, int range, struct re_registers *regs, int stop));
 482
 483
 484 /* Like `re_search', but return how many characters in STRING the regexp
 485    in BUFFER matched, starting at position START.  */
 486 extern int re_match
 487   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 488              int length, int start, struct re_registers *regs));
 489
 490
 491 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
 492 extern int re_match_2
 493   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 494              int length1, const char *string2, int length2,
 495              int start, struct re_registers *regs, int stop));
 496
 497
 498 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
 499    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
 500    for recording register information.  STARTS and ENDS must be
 501    allocated with malloc, and must each be at least `NUM_REGS * sizeof
 502    (regoff_t)' bytes long.
 503
 504    If NUM_REGS == 0, then subsequent matches should allocate their own
 505    register data.
 506
 507    Unless this function is called, the first search or match using
 508    PATTERN_BUFFER will allocate its own register data, without
 509    freeing the old data.  */
 510 extern void re_set_registers
 511   _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
 512              unsigned num_regs, regoff_t *starts, regoff_t *ends));
 513
 514 #if defined _REGEX_RE_COMP || defined _LIBC
 515 # ifndef _CRAY
 516 /* 4.2 bsd compatibility.  */
 517 extern char *re_comp _RE_ARGS ((const char *));
 518 extern int re_exec _RE_ARGS ((const char *));
 519 # endif
 520 #endif
 521
 522 /* GCC 2.95 and later have "__restrict"; C99 compilers have
 523    "restrict", and "configure" may have defined "restrict".  */
 524 #ifndef __restrict
 525 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
 526 #  if defined restrict || 199901L <= __STDC_VERSION__
 527 #   define __restrict restrict
 528 #  else
 529 #   define __restrict
 530 #  endif
 531 # endif
 532 #endif
 533 /* For now unconditionally define __restrict_arr to expand to nothing.
 534    Ideally we would have a test for the compiler which allows defining
 535    it to restrict.  */
 536 #define __restrict_arr
 537
 538 /* POSIX compatibility.  */
 539 extern int regcomp _RE_ARGS ((regex_t *__restrict __preg,
 540                               const char *__restrict __pattern,
 541                               int __cflags));
 542
 543 extern int regexec _RE_ARGS ((const regex_t *__restrict __preg,
 544                               const char *__restrict __string, size_t __nmatch,
 545                               regmatch_t __pmatch[__restrict_arr],
 546                               int __eflags));
 547
 548 extern size_t regerror _RE_ARGS ((int __errcode, const regex_t *__preg,
 549                                   char *__errbuf, size_t __errbuf_size));
 550
 551 extern void regfree _RE_ARGS ((regex_t *__preg));
 552
 553
 554 #ifdef __cplusplus
 555 }
 556 #endif  /* C++ */
 557
 558 #endif /* regex.h */
 559 \f
 560 /*
 561 Local variables:
 562 make-backup-files: t
 563 version-control: t
 564 trim-versions-without-asking: nil
 565 End:
 566 */