lib/regex.h

   1 /* Definitions for data structures and routines for the regular
   2    expression library, version 0.12.
   3    Copyright (C) 1985,1989-93,1995-98,2000,2001 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 _REGEX_H
  23 #define _REGEX_H 1
  24
  25 /* Allow the use in C++ code.  */
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 /* POSIX says that <sys/types.h> must be included (by the caller) before
  31    <regex.h>.  */
  32
  33 #if !defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE && defined VMS
  34 /* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
  35    should be there.  */
  36 # include <stddef.h>
  37 #endif
  38
  39 /* The following two types have to be signed and unsigned integer type
  40    wide enough to hold a value of a pointer.  For most ANSI compilers
  41    ptrdiff_t and size_t should be likely OK.  Still size of these two
  42    types is 2 for Microsoft C.  Ugh... */
  43 typedef long int s_reg_t;
  44 typedef unsigned long int active_reg_t;
  45
  46 /* The following bits are used to determine the regexp syntax we
  47    recognize.  The set/not-set meanings are chosen so that Emacs syntax
  48    remains the value 0.  The bits are given in alphabetical order, and
  49    the definitions shifted by one from the previous bit; thus, when we
  50    add or remove a bit, only one other definition need change.  */
  51 typedef unsigned long int reg_syntax_t;
  52
  53 /* If this bit is not set, then \ inside a bracket expression is literal.
  54    If set, then such a \ quotes the following character.  */
  55 #define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
  56
  57 /* If this bit is not set, then + and ? are operators, and \+ and \? are
  58      literals.
  59    If set, then \+ and \? are operators and + and ? are literals.  */
  60 #define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
  61
  62 /* If this bit is set, then character classes are supported.  They are:
  63      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
  64      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
  65    If not set, then character classes are not supported.  */
  66 #define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
  67
  68 /* If this bit is set, then ^ and $ are always anchors (outside bracket
  69      expressions, of course).
  70    If this bit is not set, then it depends:
  71         ^  is an anchor if it is at the beginning of a regular
  72            expression or after an open-group or an alternation operator;
  73         $  is an anchor if it is at the end of a regular expression, or
  74            before a close-group or an alternation operator.
  75
  76    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
  77    POSIX draft 11.2 says that * etc. in leading positions is undefined.
  78    We already implemented a previous draft which made those constructs
  79    invalid, though, so we haven't changed the code back.  */
  80 #define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
  81
  82 /* If this bit is set, then special characters are always special
  83      regardless of where they are in the pattern.
  84    If this bit is not set, then special characters are special only in
  85      some contexts; otherwise they are ordinary.  Specifically,
  86      * + ? and intervals are only special when not after the beginning,
  87      open-group, or alternation operator.  */
  88 #define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
  89
  90 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
  91      immediately after an alternation or begin-group operator.  */
  92 #define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
  93
  94 /* If this bit is set, then . matches newline.
  95    If not set, then it doesn't.  */
  96 #define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
  97
  98 /* If this bit is set, then . doesn't match NUL.
  99    If not set, then it does.  */
 100 #define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
 101
 102 /* If this bit is set, nonmatching lists [^...] do not match newline.
 103    If not set, they do.  */
 104 #define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
 105
 106 /* If this bit is set, either \{...\} or {...} defines an
 107      interval, depending on RE_NO_BK_BRACES.
 108    If not set, \{, \}, {, and } are literals.  */
 109 #define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
 110
 111 /* If this bit is set, +, ? and | aren't recognized as operators.
 112    If not set, they are.  */
 113 #define RE_LIMITED_OPS (RE_INTERVALS << 1)
 114
 115 /* If this bit is set, newline is an alternation operator.
 116    If not set, newline is literal.  */
 117 #define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
 118
 119 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
 120      are literals.
 121   If not set, then `\{...\}' defines an interval.  */
 122 #define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
 123
 124 /* If this bit is set, (...) defines a group, and \( and \) are literals.
 125    If not set, \(...\) defines a group, and ( and ) are literals.  */
 126 #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
 127
 128 /* If this bit is set, then \<digit> matches <digit>.
 129    If not set, then \<digit> is a back-reference.  */
 130 #define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
 131
 132 /* If this bit is set, then | is an alternation operator, and \| is literal.
 133    If not set, then \| is an alternation operator, and | is literal.  */
 134 #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
 135
 136 /* If this bit is set, then an ending range point collating higher
 137      than the starting range point, as in [z-a], is invalid.
 138    If not set, then when ending range point collates higher than the
 139      starting range point, the range is ignored.  */
 140 #define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
 141
 142 /* If this bit is set, then an unmatched ) is ordinary.
 143    If not set, then an unmatched ) is invalid.  */
 144 #define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
 145
 146 /* If this bit is set, succeed as soon as we match the whole pattern,
 147    without further backtracking.  */
 148 #define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
 149
 150 /* If this bit is set, do not process the GNU regex operators.
 151    If not set, then the GNU regex operators are recognized. */
 152 #define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
 153
 154 /* If this bit is set, turn on internal regex debugging.
 155    If not set, and debugging was on, turn it off.
 156    This only works if regex.c is compiled -DDEBUG.
 157    We define this bit always, so that all that's needed to turn on
 158    debugging is to recompile regex.c; the calling code can always have
 159    this bit set, and it won't affect anything in the normal case. */
 160 #define RE_DEBUG (RE_NO_GNU_OPS << 1)
 161
 162 /* If this bit is set, a syntactically invalid interval is treated as
 163    a string of ordinary characters.  For example, the ERE 'a{1' is
 164    treated as 'a\{1'.  */
 165 #define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
 166
 167 /* This global variable defines the particular regexp syntax to use (for
 168    some interfaces).  When a regexp is compiled, the syntax used is
 169    stored in the pattern buffer, so changing this does not affect
 170    already-compiled regexps.  */
 171 extern reg_syntax_t re_syntax_options;
 172 \f
 173 /* Define combinations of the above bits for the standard possibilities.
 174    (The [[[ comments delimit what gets put into the Texinfo file, so
 175    don't delete them!)  */
 176 /* [[[begin syntaxes]]] */
 177 #define RE_SYNTAX_EMACS 0
 178
 179 #define RE_SYNTAX_AWK                                                   \
 180   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                     \
 181    | RE_NO_BK_PARENS              | RE_NO_BK_REFS                       \
 182    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                  \
 183    | RE_DOT_NEWLINE               | RE_CONTEXT_INDEP_ANCHORS            \
 184    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
 185
 186 #define RE_SYNTAX_GNU_AWK                                               \
 187   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG) \
 188    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS))
 189
 190 #define RE_SYNTAX_POSIX_AWK                                             \
 191   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS              \
 192    | RE_INTERVALS           | RE_NO_GNU_OPS)
 193
 194 #define RE_SYNTAX_GREP                                                  \
 195   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
 196    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
 197    | RE_NEWLINE_ALT)
 198
 199 #define RE_SYNTAX_EGREP                                                 \
 200   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
 201    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
 202    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
 203    | RE_NO_BK_VBAR)
 204
 205 #define RE_SYNTAX_POSIX_EGREP                                           \
 206   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES                     \
 207    | RE_INVALID_INTERVAL_ORD)
 208
 209 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
 210 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
 211
 212 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
 213
 214 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
 215 #define _RE_SYNTAX_POSIX_COMMON                                         \
 216   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
 217    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
 218
 219 #define RE_SYNTAX_POSIX_BASIC                                           \
 220   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
 221
 222 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
 223    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
 224    isn't minimal, since other operators, such as \`, aren't disabled.  */
 225 #define RE_SYNTAX_POSIX_MINIMAL_BASIC                                   \
 226   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
 227
 228 #define RE_SYNTAX_POSIX_EXTENDED                                        \
 229   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 230    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                           \
 231    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                             \
 232    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
 233
 234 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
 235    removed and RE_NO_BK_REFS is added.  */
 236 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                                \
 237   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 238    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
 239    | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
 240    | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)
 241 /* [[[end syntaxes]]] */
 242 \f
 243 /* Maximum number of duplicates an interval can allow.  Some systems
 244    (erroneously) define this in other header files, but we want our
 245    value, so remove any previous define.  */
 246 #ifdef RE_DUP_MAX
 247 # undef RE_DUP_MAX
 248 #endif
 249 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
 250 #define RE_DUP_MAX (0x7fff)
 251
 252
 253 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
 254
 255 /* If this bit is set, then use extended regular expression syntax.
 256    If not set, then use basic regular expression syntax.  */
 257 #define REG_EXTENDED 1
 258
 259 /* If this bit is set, then ignore case when matching.
 260    If not set, then case is significant.  */
 261 #define REG_ICASE (REG_EXTENDED << 1)
 262
 263 /* If this bit is set, then anchors do not match at newline
 264      characters in the string.
 265    If not set, then anchors do match at newlines.  */
 266 #define REG_NEWLINE (REG_ICASE << 1)
 267
 268 /* If this bit is set, then report only success or fail in regexec.
 269    If not set, then returns differ between not matching and errors.  */
 270 #define REG_NOSUB (REG_NEWLINE << 1)
 271
 272
 273 /* POSIX `eflags' bits (i.e., information for regexec).  */
 274
 275 /* If this bit is set, then the beginning-of-line operator doesn't match
 276      the beginning of the string (presumably because it's not the
 277      beginning of a line).
 278    If not set, then the beginning-of-line operator does match the
 279      beginning of the string.  */
 280 #define REG_NOTBOL 1
 281
 282 /* Like REG_NOTBOL, except for the end-of-line.  */
 283 #define REG_NOTEOL (1 << 1)
 284
 285
 286 /* If any error codes are removed, changed, or added, update the
 287    `re_error_msg' table in regex.c.  */
 288 typedef enum
 289 {
 290 #ifdef _XOPEN_SOURCE
 291   REG_ENOSYS = -1,      /* This will never happen for this implementation.  */
 292 #endif
 293
 294   REG_NOERROR = 0,      /* Success.  */
 295   REG_NOMATCH,          /* Didn't find a match (for regexec).  */
 296
 297   /* POSIX regcomp return error codes.  (In the order listed in the
 298      standard.)  */
 299   REG_BADPAT,           /* Invalid pattern.  */
 300   REG_ECOLLATE,         /* Not implemented.  */
 301   REG_ECTYPE,           /* Invalid character class name.  */
 302   REG_EESCAPE,          /* Trailing backslash.  */
 303   REG_ESUBREG,          /* Invalid back reference.  */
 304   REG_EBRACK,           /* Unmatched left bracket.  */
 305   REG_EPAREN,           /* Parenthesis imbalance.  */
 306   REG_EBRACE,           /* Unmatched \{.  */
 307   REG_BADBR,            /* Invalid contents of \{\}.  */
 308   REG_ERANGE,           /* Invalid range end.  */
 309   REG_ESPACE,           /* Ran out of memory.  */
 310   REG_BADRPT,           /* No preceding re for repetition op.  */
 311
 312   /* Error codes we've added.  */
 313   REG_EEND,             /* Premature end.  */
 314   REG_ESIZE,            /* Compiled pattern bigger than 2^16 bytes.  */
 315   REG_ERPAREN           /* Unmatched ) or \); not returned from regcomp.  */
 316 } reg_errcode_t;
 317 \f
 318 /* This data structure represents a compiled pattern.  Before calling
 319    the pattern compiler, the fields `buffer', `allocated', `fastmap',
 320    `translate', and `no_sub' can be set.  After the pattern has been
 321    compiled, the `re_nsub' field is available.  All other fields are
 322    private to the regex routines.  */
 323
 324 #ifndef RE_TRANSLATE_TYPE
 325 # define RE_TRANSLATE_TYPE char *
 326 #endif
 327
 328 struct re_pattern_buffer
 329 {
 330 /* [[[begin pattern_buffer]]] */
 331         /* Space that holds the compiled pattern.  It is declared as
 332           `unsigned char *' because its elements are
 333            sometimes used as array indexes.  */
 334   unsigned char *buffer;
 335
 336         /* Number of bytes to which `buffer' points.  */
 337   unsigned long int allocated;
 338
 339         /* Number of bytes actually used in `buffer'.  */
 340   unsigned long int used;
 341
 342         /* Syntax setting with which the pattern was compiled.  */
 343   reg_syntax_t syntax;
 344
 345         /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
 346            the fastmap, if there is one, to skip over impossible
 347            starting points for matches.  */
 348   char *fastmap;
 349
 350         /* Either a translate table to apply to all characters before
 351            comparing them, or zero for no translation.  The translation
 352            is applied to a pattern when it is compiled and to a string
 353            when it is matched.  */
 354   RE_TRANSLATE_TYPE translate;
 355
 356         /* Number of subexpressions found by the compiler.  */
 357   size_t re_nsub;
 358
 359         /* Zero if this pattern cannot match the empty string, one else.
 360            Well, in truth it's used only in `re_search_2', to see
 361            whether or not we should use the fastmap, so we don't set
 362            this absolutely perfectly; see `re_compile_fastmap' (the
 363            `duplicate' case).  */
 364   unsigned can_be_null : 1;
 365
 366         /* If REGS_UNALLOCATED, allocate space in the `regs' structure
 367              for `max (RE_NREGS, re_nsub + 1)' groups.
 368            If REGS_REALLOCATE, reallocate space if necessary.
 369            If REGS_FIXED, use what's there.  */
 370 #define REGS_UNALLOCATED 0
 371 #define REGS_REALLOCATE 1
 372 #define REGS_FIXED 2
 373   unsigned regs_allocated : 2;
 374
 375         /* Set to zero when `regex_compile' compiles a pattern; set to one
 376            by `re_compile_fastmap' if it updates the fastmap.  */
 377   unsigned fastmap_accurate : 1;
 378
 379         /* If set, `re_match_2' does not return information about
 380            subexpressions.  */
 381   unsigned no_sub : 1;
 382
 383         /* If set, a beginning-of-line anchor doesn't match at the
 384            beginning of the string.  */
 385   unsigned not_bol : 1;
 386
 387         /* Similarly for an end-of-line anchor.  */
 388   unsigned not_eol : 1;
 389
 390         /* If true, an anchor at a newline matches.  */
 391   unsigned newline_anchor : 1;
 392
 393 /* [[[end pattern_buffer]]] */
 394 };
 395
 396 typedef struct re_pattern_buffer regex_t;
 397 \f
 398 /* Type for byte offsets within the string.  POSIX mandates this.  */
 399 typedef int regoff_t;
 400
 401
 402 /* This is the structure we store register match data in.  See
 403    regex.texinfo for a full description of what registers match.  */
 404 struct re_registers
 405 {
 406   unsigned num_regs;
 407   regoff_t *start;
 408   regoff_t *end;
 409 };
 410
 411
 412 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
 413    `re_match_2' returns information about at least this many registers
 414    the first time a `regs' structure is passed.  */
 415 #ifndef RE_NREGS
 416 # define RE_NREGS 30
 417 #endif
 418
 419
 420 /* POSIX specification for registers.  Aside from the different names than
 421    `re_registers', POSIX uses an array of structures, instead of a
 422    structure of arrays.  */
 423 typedef struct
 424 {
 425   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
 426   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
 427 } regmatch_t;
 428 \f
 429 /* Declarations for routines.  */
 430
 431 /* To avoid duplicating every routine declaration -- once with a
 432    prototype (if we are ANSI), and once without (if we aren't) -- we
 433    use the following macro to declare argument types.  This
 434    unfortunately clutters up the declarations a bit, but I think it's
 435    worth it.  */
 436
 437 #if __STDC__
 438
 439 # define _RE_ARGS(args) args
 440
 441 #else /* not __STDC__ */
 442
 443 # define _RE_ARGS(args) ()
 444
 445 #endif /* not __STDC__ */
 446
 447 /* Sets the current default syntax to SYNTAX, and return the old syntax.
 448    You can also simply assign to the `re_syntax_options' variable.  */
 449 extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
 450
 451 /* Compile the regular expression PATTERN, with length LENGTH
 452    and syntax given by the global `re_syntax_options', into the buffer
 453    BUFFER.  Return NULL if successful, and an error string if not.  */
 454 extern const char *re_compile_pattern
 455   _RE_ARGS ((const char *pattern, size_t length,
 456              struct re_pattern_buffer *buffer));
 457
 458
 459 /* Compile a fastmap for the compiled pattern in BUFFER; used to
 460    accelerate searches.  Return 0 if successful and -2 if was an
 461    internal error.  */
 462 extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
 463
 464
 465 /* Search in the string STRING (with length LENGTH) for the pattern
 466    compiled into BUFFER.  Start searching at position START, for RANGE
 467    characters.  Return the starting position of the match, -1 for no
 468    match, or -2 for an internal error.  Also return register
 469    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
 470 extern int re_search
 471   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 472             int length, int start, int range, struct re_registers *regs));
 473
 474
 475 /* Like `re_search', but search in the concatenation of STRING1 and
 476    STRING2.  Also, stop searching at index START + STOP.  */
 477 extern int re_search_2
 478   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 479              int length1, const char *string2, int length2,
 480              int start, int range, struct re_registers *regs, int stop));
 481
 482
 483 /* Like `re_search', but return how many characters in STRING the regexp
 484    in BUFFER matched, starting at position START.  */
 485 extern int re_match
 486   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 487              int length, int start, struct re_registers *regs));
 488
 489
 490 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
 491 extern int re_match_2
 492   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 493              int length1, const char *string2, int length2,
 494              int start, struct re_registers *regs, int stop));
 495
 496
 497 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
 498    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
 499    for recording register information.  STARTS and ENDS must be
 500    allocated with malloc, and must each be at least `NUM_REGS * sizeof
 501    (regoff_t)' bytes long.
 502
 503    If NUM_REGS == 0, then subsequent matches should allocate their own
 504    register data.
 505
 506    Unless this function is called, the first search or match using
 507    PATTERN_BUFFER will allocate its own register data, without
 508    freeing the old data.  */
 509 extern void re_set_registers
 510   _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
 511              unsigned num_regs, regoff_t *starts, regoff_t *ends));
 512
 513 #if defined _REGEX_RE_COMP || defined _LIBC
 514 # ifndef _CRAY
 515 /* 4.2 bsd compatibility.  */
 516 extern char *re_comp _RE_ARGS ((const char *));
 517 extern int re_exec _RE_ARGS ((const char *));
 518 # endif
 519 #endif
 520
 521 /* GCC 2.95 and later have "__restrict"; C99 compilers have
 522    "restrict", and "configure" may have defined "restrict".  */
 523 #ifndef __restrict
 524 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
 525 #  if defined restrict || 199901L <= __STDC_VERSION__
 526 #   define __restrict restrict
 527 #  else
 528 #   define __restrict
 529 #  endif
 530 # endif
 531 #endif
 532 /* gcc 3.1 and up support the [restrict] syntax.  */
 533 #ifndef __restrict_arr
 534 # if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
 535 #  define __restrict_arr __restrict
 536 # else
 537 #  define __restrict_arr
 538 # endif
 539 #endif
 540
 541 /* POSIX compatibility.  */
 542 extern int regcomp _RE_ARGS ((regex_t *__restrict __preg,
 543                               const char *__restrict __pattern,
 544                               int __cflags));
 545
 546 extern int regexec _RE_ARGS ((const regex_t *__restrict __preg,
 547                               const char *__restrict __string, size_t __nmatch,
 548                               regmatch_t __pmatch[__restrict_arr],
 549                               int __eflags));
 550
 551 extern size_t regerror _RE_ARGS ((int __errcode, const regex_t *__preg,
 552                                   char *__errbuf, size_t __errbuf_size));
 553
 554 extern void regfree _RE_ARGS ((regex_t *__preg));
 555
 556
 557 #ifdef __cplusplus
 558 }
 559 #endif  /* C++ */
 560
 561 #endif /* regex.h */
 562 \f
 563 /*
 564 Local variables:
 565 make-backup-files: t
 566 version-control: t
 567 trim-versions-without-asking: nil
 568 End:
 569 */