src/regex.h

   1 /* Definitions for data structures and routines for the regular
   2    expression library, version 0.12.
   3
   4    Copyright (C) 1985,89,90,91,92,93,95,2000 Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19    USA.  */
  20
  21 #ifndef _REGEX_H
  22 #define _REGEX_H 1
  23
  24 /* Allow the use in C++ code.  */
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif
  28
  29 /* POSIX says that <sys/types.h> must be included (by the caller) before
  30    <regex.h>.  */
  31
  32 #if !defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE && defined VMS
  33 /* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
  34    should be there.  */
  35 # include <stddef.h>
  36 #endif
  37
  38 /* The following bits are used to determine the regexp syntax we
  39    recognize.  The set/not-set meanings where historically chosen so
  40    that Emacs syntax had the value 0.
  41    The bits are given in alphabetical order, and
  42    the definitions shifted by one from the previous bit; thus, when we
  43    add or remove a bit, only one other definition need change.  */
  44 typedef unsigned long int reg_syntax_t;
  45
  46 /* If this bit is not set, then \ inside a bracket expression is literal.
  47    If set, then such a \ quotes the following character.  */
  48 #define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
  49
  50 /* If this bit is not set, then + and ? are operators, and \+ and \? are
  51      literals.
  52    If set, then \+ and \? are operators and + and ? are literals.  */
  53 #define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
  54
  55 /* If this bit is set, then character classes are supported.  They are:
  56      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
  57      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
  58    If not set, then character classes are not supported.  */
  59 #define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
  60
  61 /* If this bit is set, then ^ and $ are always anchors (outside bracket
  62      expressions, of course).
  63    If this bit is not set, then it depends:
  64         ^  is an anchor if it is at the beginning of a regular
  65            expression or after an open-group or an alternation operator;
  66         $  is an anchor if it is at the end of a regular expression, or
  67            before a close-group or an alternation operator.
  68
  69    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
  70    POSIX draft 11.2 says that * etc. in leading positions is undefined.
  71    We already implemented a previous draft which made those constructs
  72    invalid, though, so we haven't changed the code back.  */
  73 #define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
  74
  75 /* If this bit is set, then special characters are always special
  76      regardless of where they are in the pattern.
  77    If this bit is not set, then special characters are special only in
  78      some contexts; otherwise they are ordinary.  Specifically,
  79      * + ? and intervals are only special when not after the beginning,
  80      open-group, or alternation operator.  */
  81 #define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
  82
  83 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
  84      immediately after an alternation or begin-group operator.  */
  85 #define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
  86
  87 /* If this bit is set, then . matches newline.
  88    If not set, then it doesn't.  */
  89 #define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
  90
  91 /* If this bit is set, then . doesn't match NUL.
  92    If not set, then it does.  */
  93 #define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
  94
  95 /* If this bit is set, nonmatching lists [^...] do not match newline.
  96    If not set, they do.  */
  97 #define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
  98
  99 /* If this bit is set, either \{...\} or {...} defines an
 100      interval, depending on RE_NO_BK_BRACES.
 101    If not set, \{, \}, {, and } are literals.  */
 102 #define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
 103
 104 /* If this bit is set, +, ? and | aren't recognized as operators.
 105    If not set, they are.  */
 106 #define RE_LIMITED_OPS (RE_INTERVALS << 1)
 107
 108 /* If this bit is set, newline is an alternation operator.
 109    If not set, newline is literal.  */
 110 #define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
 111
 112 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
 113      are literals.
 114   If not set, then `\{...\}' defines an interval.  */
 115 #define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
 116
 117 /* If this bit is set, (...) defines a group, and \( and \) are literals.
 118    If not set, \(...\) defines a group, and ( and ) are literals.  */
 119 #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
 120
 121 /* If this bit is set, then \<digit> matches <digit>.
 122    If not set, then \<digit> is a back-reference.  */
 123 #define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
 124
 125 /* If this bit is set, then | is an alternation operator, and \| is literal.
 126    If not set, then \| is an alternation operator, and | is literal.  */
 127 #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
 128
 129 /* If this bit is set, then an ending range point collating higher
 130      than the starting range point, as in [z-a], is invalid.
 131    If not set, then when ending range point collates higher than the
 132      starting range point, the range is ignored.  */
 133 #define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
 134
 135 /* If this bit is set, then an unmatched ) is ordinary.
 136    If not set, then an unmatched ) is invalid.  */
 137 #define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
 138
 139 /* If this bit is set, succeed as soon as we match the whole pattern,
 140    without further backtracking.  */
 141 #define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
 142
 143 /* If this bit is set, do not process the GNU regex operators.
 144    If not set, then the GNU regex operators are recognized. */
 145 #define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
 146
 147 /* If this bit is set, then *?, +? and ?? match non greedily. */
 148 #define RE_FRUGAL (RE_NO_GNU_OPS << 1)
 149
 150 /* If this bit is set, then (?:...) is treated as a shy group.  */
 151 #define RE_SHY_GROUPS (RE_FRUGAL << 1)
 152
 153 /* If this bit is set, ^ and $ only match at beg/end of buffer.  */
 154 #define RE_NO_NEWLINE_ANCHOR (RE_SHY_GROUPS << 1)
 155
 156 /* If this bit is set, turn on internal regex debugging.
 157    If not set, and debugging was on, turn it off.
 158    This only works if regex.c is compiled -DDEBUG.
 159    We define this bit always, so that all that's needed to turn on
 160    debugging is to recompile regex.c; the calling code can always have
 161    this bit set, and it won't affect anything in the normal case. */
 162 #define RE_DEBUG (RE_NO_NEWLINE_ANCHOR << 1)
 163
 164 /* This global variable defines the particular regexp syntax to use (for
 165    some interfaces).  When a regexp is compiled, the syntax used is
 166    stored in the pattern buffer, so changing this does not affect
 167    already-compiled regexps.  */
 168 extern reg_syntax_t re_syntax_options;
 169
 170 #ifdef emacs
 171 /* In Emacs, this is the string or buffer in which we
 172    are matching.  It is used for looking up syntax properties.  */
 173 extern Lisp_Object re_match_object;
 174 #endif
 175
 176 \f
 177 /* Define combinations of the above bits for the standard possibilities.
 178    (The [[[ comments delimit what gets put into the Texinfo file, so
 179    don't delete them!)  */
 180 /* [[[begin syntaxes]]] */
 181 #define RE_SYNTAX_EMACS                                                 \
 182   (RE_CHAR_CLASSES | RE_INTERVALS | RE_SHY_GROUPS | RE_FRUGAL)
 183
 184 #define RE_SYNTAX_AWK                                                   \
 185   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                     \
 186    | RE_NO_BK_PARENS              | RE_NO_BK_REFS                       \
 187    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                  \
 188    | RE_DOT_NEWLINE               | RE_CONTEXT_INDEP_ANCHORS            \
 189    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
 190
 191 #define RE_SYNTAX_GNU_AWK                                               \
 192   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG) \
 193    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS))
 194
 195 #define RE_SYNTAX_POSIX_AWK                                             \
 196   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS              \
 197    | RE_INTERVALS           | RE_NO_GNU_OPS)
 198
 199 #define RE_SYNTAX_GREP                                                  \
 200   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
 201    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
 202    | RE_NEWLINE_ALT)
 203
 204 #define RE_SYNTAX_EGREP                                                 \
 205   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
 206    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
 207    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
 208    | RE_NO_BK_VBAR)
 209
 210 #define RE_SYNTAX_POSIX_EGREP                                           \
 211   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES)
 212
 213 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
 214 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
 215
 216 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
 217
 218 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
 219 #define _RE_SYNTAX_POSIX_COMMON                                         \
 220   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
 221    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
 222
 223 #define RE_SYNTAX_POSIX_BASIC                                           \
 224   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
 225
 226 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
 227    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
 228    isn't minimal, since other operators, such as \`, aren't disabled.  */
 229 #define RE_SYNTAX_POSIX_MINIMAL_BASIC                                   \
 230   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
 231
 232 #define RE_SYNTAX_POSIX_EXTENDED                                        \
 233   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 234    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                           \
 235    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                             \
 236    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
 237
 238 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
 239    removed and RE_NO_BK_REFS is added.  */
 240 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                                \
 241   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 242    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
 243    | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
 244    | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)
 245 /* [[[end syntaxes]]] */
 246 \f
 247 /* Maximum number of duplicates an interval can allow.  Some systems
 248    (erroneously) define this in other header files, but we want our
 249    value, so remove any previous define.  */
 250 #ifdef RE_DUP_MAX
 251 # undef RE_DUP_MAX
 252 #endif
 253 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
 254 #define RE_DUP_MAX (0x7fff)
 255
 256
 257 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
 258
 259 /* If this bit is set, then use extended regular expression syntax.
 260    If not set, then use basic regular expression syntax.  */
 261 #define REG_EXTENDED 1
 262
 263 /* If this bit is set, then ignore case when matching.
 264    If not set, then case is significant.  */
 265 #define REG_ICASE (REG_EXTENDED << 1)
 266
 267 /* If this bit is set, then anchors do not match at newline
 268      characters in the string.
 269    If not set, then anchors do match at newlines.  */
 270 #define REG_NEWLINE (REG_ICASE << 1)
 271
 272 /* If this bit is set, then report only success or fail in regexec.
 273    If not set, then returns differ between not matching and errors.  */
 274 #define REG_NOSUB (REG_NEWLINE << 1)
 275
 276
 277 /* POSIX `eflags' bits (i.e., information for regexec).  */
 278
 279 /* If this bit is set, then the beginning-of-line operator doesn't match
 280      the beginning of the string (presumably because it's not the
 281      beginning of a line).
 282    If not set, then the beginning-of-line operator does match the
 283      beginning of the string.  */
 284 #define REG_NOTBOL 1
 285
 286 /* Like REG_NOTBOL, except for the end-of-line.  */
 287 #define REG_NOTEOL (1 << 1)
 288
 289
 290 /* If any error codes are removed, changed, or added, update the
 291    `re_error_msg' table in regex.c.  */
 292 typedef enum
 293 {
 294 #ifdef _XOPEN_SOURCE
 295   REG_ENOSYS = -1,      /* This will never happen for this implementation.  */
 296 #endif
 297
 298   REG_NOERROR = 0,      /* Success.  */
 299   REG_NOMATCH,          /* Didn't find a match (for regexec).  */
 300
 301   /* POSIX regcomp return error codes.  (In the order listed in the
 302      standard.)  */
 303   REG_BADPAT,           /* Invalid pattern.  */
 304   REG_ECOLLATE,         /* Not implemented.  */
 305   REG_ECTYPE,           /* Invalid character class name.  */
 306   REG_EESCAPE,          /* Trailing backslash.  */
 307   REG_ESUBREG,          /* Invalid back reference.  */
 308   REG_EBRACK,           /* Unmatched left bracket.  */
 309   REG_EPAREN,           /* Parenthesis imbalance.  */
 310   REG_EBRACE,           /* Unmatched \{.  */
 311   REG_BADBR,            /* Invalid contents of \{\}.  */
 312   REG_ERANGE,           /* Invalid range end.  */
 313   REG_ESPACE,           /* Ran out of memory.  */
 314   REG_BADRPT,           /* No preceding re for repetition op.  */
 315
 316   /* Error codes we've added.  */
 317   REG_EEND,             /* Premature end.  */
 318   REG_ESIZE,            /* Compiled pattern bigger than 2^16 bytes.  */
 319   REG_ERPAREN           /* Unmatched ) or \); not returned from regcomp.  */
 320 } reg_errcode_t;
 321 \f
 322 /* This data structure represents a compiled pattern.  Before calling
 323    the pattern compiler, the fields `buffer', `allocated', `fastmap',
 324    `translate', and `no_sub' can be set.  After the pattern has been
 325    compiled, the `re_nsub' field is available.  All other fields are
 326    private to the regex routines.  */
 327
 328 #ifndef RE_TRANSLATE_TYPE
 329 # define RE_TRANSLATE_TYPE char *
 330 #endif
 331
 332 struct re_pattern_buffer
 333 {
 334 /* [[[begin pattern_buffer]]] */
 335         /* Space that holds the compiled pattern.  It is declared as
 336           `unsigned char *' because its elements are
 337            sometimes used as array indexes.  */
 338   unsigned char *buffer;
 339
 340         /* Number of bytes to which `buffer' points.  */
 341   size_t allocated;
 342
 343         /* Number of bytes actually used in `buffer'.  */
 344   size_t used;
 345
 346         /* Syntax setting with which the pattern was compiled.  */
 347   reg_syntax_t syntax;
 348
 349         /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
 350            the fastmap, if there is one, to skip over impossible
 351            starting points for matches.  */
 352   char *fastmap;
 353
 354         /* Either a translate table to apply to all characters before
 355            comparing them, or zero for no translation.  The translation
 356            is applied to a pattern when it is compiled and to a string
 357            when it is matched.  */
 358   RE_TRANSLATE_TYPE translate;
 359
 360         /* Number of subexpressions found by the compiler.  */
 361   size_t re_nsub;
 362
 363         /* Zero if this pattern cannot match the empty string, one else.
 364            Well, in truth it's used only in `re_search_2', to see
 365            whether or not we should use the fastmap, so we don't set
 366            this absolutely perfectly; see `re_compile_fastmap'.  */
 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 #ifdef emacs
 394   /* If true, multi-byte form in the `buffer' should be recognized as a
 395      multibyte character. */
 396   unsigned multibyte : 1;
 397 #endif
 398
 399 /* [[[end pattern_buffer]]] */
 400 };
 401
 402 typedef struct re_pattern_buffer regex_t;
 403 \f
 404 /* Type for byte offsets within the string.  POSIX mandates this.  */
 405 typedef int regoff_t;
 406
 407
 408 /* This is the structure we store register match data in.  See
 409    regex.texinfo for a full description of what registers match.  */
 410 struct re_registers
 411 {
 412   unsigned num_regs;
 413   regoff_t *start;
 414   regoff_t *end;
 415 };
 416
 417
 418 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
 419    `re_match_2' returns information about at least this many registers
 420    the first time a `regs' structure is passed.  */
 421 #ifndef RE_NREGS
 422 # define RE_NREGS 30
 423 #endif
 424
 425
 426 /* POSIX specification for registers.  Aside from the different names than
 427    `re_registers', POSIX uses an array of structures, instead of a
 428    structure of arrays.  */
 429 typedef struct
 430 {
 431   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
 432   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
 433 } regmatch_t;
 434 \f
 435 /* Declarations for routines.  */
 436
 437 /* To avoid duplicating every routine declaration -- once with a
 438    prototype (if we are ANSI), and once without (if we aren't) -- we
 439    use the following macro to declare argument types.  This
 440    unfortunately clutters up the declarations a bit, but I think it's
 441    worth it.  */
 442
 443 #if defined __STDC__ || defined PROTOTYPES
 444
 445 # define _RE_ARGS(args) args
 446
 447 #else /* not __STDC__  || PROTOTYPES */
 448
 449 # define _RE_ARGS(args) ()
 450
 451 #endif /* not __STDC__  || PROTOTYPES */
 452
 453 /* Sets the current default syntax to SYNTAX, and return the old syntax.
 454    You can also simply assign to the `re_syntax_options' variable.  */
 455 extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
 456
 457 /* Compile the regular expression PATTERN, with length LENGTH
 458    and syntax given by the global `re_syntax_options', into the buffer
 459    BUFFER.  Return NULL if successful, and an error string if not.  */
 460 extern const char *re_compile_pattern
 461   _RE_ARGS ((const char *pattern, size_t length,
 462              struct re_pattern_buffer *buffer));
 463
 464
 465 /* Compile a fastmap for the compiled pattern in BUFFER; used to
 466    accelerate searches.  Return 0 if successful and -2 if was an
 467    internal error.  */
 468 extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
 469
 470
 471 /* Search in the string STRING (with length LENGTH) for the pattern
 472    compiled into BUFFER.  Start searching at position START, for RANGE
 473    characters.  Return the starting position of the match, -1 for no
 474    match, or -2 for an internal error.  Also return register
 475    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
 476 extern int re_search
 477   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 478             int length, int start, int range, struct re_registers *regs));
 479
 480
 481 /* Like `re_search', but search in the concatenation of STRING1 and
 482    STRING2.  Also, stop searching at index START + STOP.  */
 483 extern int re_search_2
 484   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 485              int length1, const char *string2, int length2,
 486              int start, int range, struct re_registers *regs, int stop));
 487
 488
 489 /* Like `re_search', but return how many characters in STRING the regexp
 490    in BUFFER matched, starting at position START.  */
 491 extern int re_match
 492   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 493              int length, int start, struct re_registers *regs));
 494
 495
 496 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
 497 extern int re_match_2
 498   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 499              int length1, const char *string2, int length2,
 500              int start, struct re_registers *regs, int stop));
 501
 502
 503 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
 504    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
 505    for recording register information.  STARTS and ENDS must be
 506    allocated with malloc, and must each be at least `NUM_REGS * sizeof
 507    (regoff_t)' bytes long.
 508
 509    If NUM_REGS == 0, then subsequent matches should allocate their own
 510    register data.
 511
 512    Unless this function is called, the first search or match using
 513    PATTERN_BUFFER will allocate its own register data, without
 514    freeing the old data.  */
 515 extern void re_set_registers
 516   _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
 517              unsigned num_regs, regoff_t *starts, regoff_t *ends));
 518
 519 #if defined _REGEX_RE_COMP || defined _LIBC
 520 # ifndef _CRAY
 521 /* 4.2 bsd compatibility.  */
 522 extern char *re_comp _RE_ARGS ((const char *));
 523 extern int re_exec _RE_ARGS ((const char *));
 524 # endif
 525 #endif
 526
 527 /* GCC 2.95 and later have "__restrict"; C99 compilers have
 528    "restrict", and "configure" may have defined "restrict".  */
 529 #ifndef __restrict
 530 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
 531 #  if defined restrict || 199901L <= __STDC_VERSION__
 532 #   define __restrict restrict
 533 #  else
 534 #   define __restrict
 535 #  endif
 536 # endif
 537 #endif
 538 /* For now unconditionally define __restrict_arr to expand to nothing.
 539    Ideally we would have a test for the compiler which allows defining
 540    it to restrict.  */
 541 #define __restrict_arr
 542
 543 /* POSIX compatibility.  */
 544 extern int regcomp _RE_ARGS ((regex_t *__restrict __preg,
 545                               const char *__restrict __pattern,
 546                               int __cflags));
 547
 548 extern int regexec _RE_ARGS ((const regex_t *__restrict __preg,
 549                               const char *__restrict __string, size_t __nmatch,
 550                               regmatch_t __pmatch[__restrict_arr],
 551                               int __eflags));
 552
 553 extern size_t regerror _RE_ARGS ((int __errcode, const regex_t *__preg,
 554                                   char *__errbuf, size_t __errbuf_size));
 555
 556 extern void regfree _RE_ARGS ((regex_t *__preg));
 557
 558
 559 #ifdef __cplusplus
 560 }
 561 #endif  /* C++ */
 562
 563 #endif /* regex.h */
 564 \f
 565 /*
 566 Local variables:
 567 make-backup-files: t
 568 version-control: t
 569 trim-versions-without-asking: nil
 570 End:
 571 */