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      1 /* Definitions for data structures and routines for the regular
      2    expression library, version 0.12.
      3 
      4    Copyright (C) 1985, 1989, 1990, 1991, 1992, 1993, 1995, 1996, 1997,
      5    1998, 2000, 2005 Free Software Foundation, Inc.
      6 
      7    This file is part of the GNU C Library.  Its master source is NOT part of
      8    the C library, however.  The master source lives in /gd/gnu/lib.
      9 
     10    The GNU C Library is free software; you can redistribute it and/or
     11    modify it under the terms of the GNU Lesser General Public
     12    License as published by the Free Software Foundation; either
     13    version 2.1 of the License, or (at your option) any later version.
     14 
     15    The GNU C Library is distributed in the hope that it will be useful,
     16    but WITHOUT ANY WARRANTY; without even the implied warranty of
     17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     18    Lesser General Public License for more details.
     19 
     20    You should have received a copy of the GNU Lesser General Public
     21    License along with the GNU C Library; if not, write to the Free
     22    Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
     23    02110-1301 USA.  */
     24 
     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 
    176 /* 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 0
    182 
    183 #define RE_SYNTAX_AWK							\
    184   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL			\
    185    | RE_NO_BK_PARENS              | RE_NO_BK_REFS			\
    186    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES			\
    187    | RE_DOT_NEWLINE		  | RE_CONTEXT_INDEP_ANCHORS		\
    188    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
    189 
    190 #define RE_SYNTAX_GNU_AWK						\
    191   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG)	\
    192    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS))
    193 
    194 #define RE_SYNTAX_POSIX_AWK 						\
    195   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS		\
    196    | RE_INTERVALS	    | RE_NO_GNU_OPS)
    197 
    198 #define RE_SYNTAX_GREP							\
    199   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES				\
    200    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS				\
    201    | RE_NEWLINE_ALT)
    202 
    203 #define RE_SYNTAX_EGREP							\
    204   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS			\
    205    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE			\
    206    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS				\
    207    | RE_NO_BK_VBAR)
    208 
    209 #define RE_SYNTAX_POSIX_EGREP						\
    210   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES			\
    211    | RE_INVALID_INTERVAL_ORD)
    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 
    247 /* Maximum number of duplicates an interval can allow.  Some systems
    249    (erroneously) define this in other header files, but we want our
    250    value, so remove any previous define.  */
    251 #ifdef RE_DUP_MAX
    252 # undef RE_DUP_MAX
    253 #endif
    254 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
    255 #define RE_DUP_MAX (0x7fff)
    256 
    257 
    258 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
    259 
    260 /* If this bit is set, then use extended regular expression syntax.
    261    If not set, then use basic regular expression syntax.  */
    262 #define REG_EXTENDED 1
    263 
    264 /* If this bit is set, then ignore case when matching.
    265    If not set, then case is significant.  */
    266 #define REG_ICASE (REG_EXTENDED << 1)
    267 
    268 /* If this bit is set, then anchors do not match at newline
    269      characters in the string.
    270    If not set, then anchors do match at newlines.  */
    271 #define REG_NEWLINE (REG_ICASE << 1)
    272 
    273 /* If this bit is set, then report only success or fail in regexec.
    274    If not set, then returns differ between not matching and errors.  */
    275 #define REG_NOSUB (REG_NEWLINE << 1)
    276 
    277 
    278 /* POSIX `eflags' bits (i.e., information for regexec).  */
    279 
    280 /* If this bit is set, then the beginning-of-line operator doesn't match
    281      the beginning of the string (presumably because it's not the
    282      beginning of a line).
    283    If not set, then the beginning-of-line operator does match the
    284      beginning of the string.  */
    285 #define REG_NOTBOL 1
    286 
    287 /* Like REG_NOTBOL, except for the end-of-line.  */
    288 #define REG_NOTEOL (1 << 1)
    289 
    290 
    291 /* If any error codes are removed, changed, or added, update the
    292    `re_error_msg' table in regex.c.  */
    293 typedef enum
    294 {
    295 #ifdef _XOPEN_SOURCE
    296   REG_ENOSYS = -1,	/* This will never happen for this implementation.  */
    297 #endif
    298 
    299   REG_NOERROR = 0,	/* Success.  */
    300   REG_NOMATCH,		/* Didn't find a match (for regexec).  */
    301 
    302   /* POSIX regcomp return error codes.  (In the order listed in the
    303      standard.)  */
    304   REG_BADPAT,		/* Invalid pattern.  */
    305   REG_ECOLLATE,		/* Not implemented.  */
    306   REG_ECTYPE,		/* Invalid character class name.  */
    307   REG_EESCAPE,		/* Trailing backslash.  */
    308   REG_ESUBREG,		/* Invalid back reference.  */
    309   REG_EBRACK,		/* Unmatched left bracket.  */
    310   REG_EPAREN,		/* Parenthesis imbalance.  */
    311   REG_EBRACE,		/* Unmatched \{.  */
    312   REG_BADBR,		/* Invalid contents of \{\}.  */
    313   REG_ERANGE,		/* Invalid range end.  */
    314   REG_ESPACE,		/* Ran out of memory.  */
    315   REG_BADRPT,		/* No preceding re for repetition op.  */
    316 
    317   /* Error codes we've added.  */
    318   REG_EEND,		/* Premature end.  */
    319   REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
    320   REG_ERPAREN		/* Unmatched ) or \); not returned from regcomp.  */
    321 } reg_errcode_t;
    322 
    323 /* This data structure represents a compiled pattern.  Before calling
    325    the pattern compiler, the fields `buffer', `allocated', `fastmap',
    326    `translate', and `no_sub' can be set.  After the pattern has been
    327    compiled, the `re_nsub' field is available.  All other fields are
    328    private to the regex routines.  */
    329 
    330 #ifndef RE_TRANSLATE_TYPE
    331 # define RE_TRANSLATE_TYPE char *
    332 #endif
    333 
    334 struct re_pattern_buffer
    335 {
    336 /* [[[begin pattern_buffer]]] */
    337 	/* Space that holds the compiled pattern.  It is declared as
    338           `unsigned char *' because its elements are
    339            sometimes used as array indexes.  */
    340   unsigned char *buffer;
    341 
    342 	/* Number of bytes to which `buffer' points.  */
    343   unsigned long int allocated;
    344 
    345 	/* Number of bytes actually used in `buffer'.  */
    346   unsigned long int used;
    347 
    348         /* Syntax setting with which the pattern was compiled.  */
    349   reg_syntax_t syntax;
    350 
    351         /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
    352            the fastmap, if there is one, to skip over impossible
    353            starting points for matches.  */
    354   char *fastmap;
    355 
    356         /* Either a translate table to apply to all characters before
    357            comparing them, or zero for no translation.  The translation
    358            is applied to a pattern when it is compiled and to a string
    359            when it is matched.  */
    360   RE_TRANSLATE_TYPE translate;
    361 
    362 	/* Number of subexpressions found by the compiler.  */
    363   size_t re_nsub;
    364 
    365         /* Zero if this pattern cannot match the empty string, one else.
    366            Well, in truth it's used only in `re_search_2', to see
    367            whether or not we should use the fastmap, so we don't set
    368            this absolutely perfectly; see `re_compile_fastmap' (the
    369            `duplicate' case).  */
    370   unsigned can_be_null : 1;
    371 
    372         /* If REGS_UNALLOCATED, allocate space in the `regs' structure
    373              for `max (RE_NREGS, re_nsub + 1)' groups.
    374            If REGS_REALLOCATE, reallocate space if necessary.
    375            If REGS_FIXED, use what's there.  */
    376 #define REGS_UNALLOCATED 0
    377 #define REGS_REALLOCATE 1
    378 #define REGS_FIXED 2
    379   unsigned regs_allocated : 2;
    380 
    381         /* Set to zero when `regex_compile' compiles a pattern; set to one
    382            by `re_compile_fastmap' if it updates the fastmap.  */
    383   unsigned fastmap_accurate : 1;
    384 
    385         /* If set, `re_match_2' does not return information about
    386            subexpressions.  */
    387   unsigned no_sub : 1;
    388 
    389         /* If set, a beginning-of-line anchor doesn't match at the
    390            beginning of the string.  */
    391   unsigned not_bol : 1;
    392 
    393         /* Similarly for an end-of-line anchor.  */
    394   unsigned not_eol : 1;
    395 
    396         /* If true, an anchor at a newline matches.  */
    397   unsigned newline_anchor : 1;
    398 
    399 /* [[[end pattern_buffer]]] */
    400 };
    401 
    402 typedef struct re_pattern_buffer regex_t;
    403 
    404 /* Type for byte offsets within the string.  POSIX mandates this.  */
    406 typedef int regoff_t;
    407 
    408 
    409 /* This is the structure we store register match data in.  See
    410    regex.texinfo for a full description of what registers match.  */
    411 struct re_registers
    412 {
    413   unsigned num_regs;
    414   regoff_t *start;
    415   regoff_t *end;
    416 };
    417 
    418 
    419 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
    420    `re_match_2' returns information about at least this many registers
    421    the first time a `regs' structure is passed.  */
    422 #ifndef RE_NREGS
    423 # define RE_NREGS 30
    424 #endif
    425 
    426 
    427 /* POSIX specification for registers.  Aside from the different names than
    428    `re_registers', POSIX uses an array of structures, instead of a
    429    structure of arrays.  */
    430 typedef struct
    431 {
    432   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
    433   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
    434 } regmatch_t;
    435 
    436 /* Declarations for routines.  */
    438 
    439 /* To avoid duplicating every routine declaration -- once with a
    440    prototype (if we are ANSI), and once without (if we aren't) -- we
    441    use the following macro to declare argument types.  This
    442    unfortunately clutters up the declarations a bit, but I think it's
    443    worth it.  */
    444 
    445 /* Sets the current default syntax to SYNTAX, and return the old syntax.
    446    You can also simply assign to the `re_syntax_options' variable.  */
    447 extern reg_syntax_t re_set_syntax (reg_syntax_t syntax);
    448 
    449 /* Compile the regular expression PATTERN, with length LENGTH
    450    and syntax given by the global `re_syntax_options', into the buffer
    451    BUFFER.  Return NULL if successful, and an error string if not.  */
    452 extern const char *re_compile_pattern (const char *pattern, size_t length,
    453                                        struct re_pattern_buffer *buffer);
    454 
    455 
    456 /* Compile a fastmap for the compiled pattern in BUFFER; used to
    457    accelerate searches.  Return 0 if successful and -2 if was an
    458    internal error.  */
    459 extern int re_compile_fastmap (struct re_pattern_buffer *buffer);
    460 
    461 
    462 /* Search in the string STRING (with length LENGTH) for the pattern
    463    compiled into BUFFER.  Start searching at position START, for RANGE
    464    characters.  Return the starting position of the match, -1 for no
    465    match, or -2 for an internal error.  Also return register
    466    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
    467 extern int re_search (struct re_pattern_buffer *buffer, const char *string,
    468                       int length, int start, int range,
    469                       struct re_registers *regs);
    470 
    471 
    472 /* Like `re_search', but search in the concatenation of STRING1 and
    473    STRING2.  Also, stop searching at index START + STOP.  */
    474 extern int re_search_2 (struct re_pattern_buffer *buffer, const char *string1,
    475                         int length1, const char *string2, int length2,
    476                         int start, int range, struct re_registers *regs,
    477                         int stop);
    478 
    479 
    480 /* Like `re_search', but return how many characters in STRING the regexp
    481    in BUFFER matched, starting at position START.  */
    482 extern int re_match (struct re_pattern_buffer *buffer, const char *string,
    483                      int length, int start, struct re_registers *regs);
    484 
    485 
    486 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
    487 extern int re_match_2 (struct re_pattern_buffer *buffer, const char *string1,
    488                        int length1, const char *string2, int length2,
    489                        int start, struct re_registers *regs, int stop);
    490 
    491 
    492 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
    493    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
    494    for recording register information.  STARTS and ENDS must be
    495    allocated with malloc, and must each be at least `NUM_REGS * sizeof
    496    (regoff_t)' bytes long.
    497 
    498    If NUM_REGS == 0, then subsequent matches should allocate their own
    499    register data.
    500 
    501    Unless this function is called, the first search or match using
    502    PATTERN_BUFFER will allocate its own register data, without
    503    freeing the old data.  */
    504 extern void re_set_registers (struct re_pattern_buffer *buffer,
    505                               struct re_registers *regs,
    506                               unsigned num_regs, regoff_t *starts,
    507                               regoff_t *ends);
    508 
    509 #if defined _REGEX_RE_COMP || defined _LIBC
    510 # ifndef _CRAY
    511 /* 4.2 bsd compatibility.  */
    512 extern char *re_comp (const char *);
    513 extern int re_exec (const char *);
    514 # endif
    515 #endif
    516 
    517 /* GCC 2.95 and later have "__restrict"; C99 compilers have
    518    "restrict", and "configure" may have defined "restrict".  */
    519 #ifndef __restrict
    520 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
    521 #  if defined restrict || 199901L <= __STDC_VERSION__
    522 #   define __restrict restrict
    523 #  else
    524 #   define __restrict
    525 #  endif
    526 # endif
    527 #endif
    528 
    529 /* GCC 3.1 and later support declaring arrays as non-overlapping
    530    using the syntax array_name[restrict]  */
    531 #ifndef __restrict_arr
    532 # if ! (3 < __GNUC__ || (3 == __GNUC__ && 1 <= __GNUC_MINOR__)) || defined (__GNUG__)
    533 #  define __restrict_arr
    534 # else
    535 #  define __restrict_arr __restrict
    536 # endif
    537 #endif
    538 
    539 /* POSIX compatibility.  */
    540 extern int regcomp (regex_t *__restrict __preg,
    541                     const char *__restrict __pattern,
    542                     int __cflags);
    543 
    544 #if (__GNUC__)
    545 __extension__
    546 #endif
    547 extern int regexec (const regex_t *__restrict __preg,
    548                     const char *__restrict __string, size_t __nmatch,
    549                     regmatch_t __pmatch[__restrict_arr],
    550                     int __eflags);
    551 
    552 extern size_t regerror (int __errcode, const regex_t *__preg,
    553                         char *__errbuf, size_t __errbuf_size);
    554 
    555 extern void regfree (regex_t *__preg);
    556 
    557 
    558 #ifdef __cplusplus
    559 }
    560 #endif	/* C++ */
    561 
    562 #endif /* regex.h */
    563 
    564 /*
    566 Local variables:
    567 make-backup-files: t
    568 version-control: t
    569 trim-versions-without-asking: nil
    570 End:
    571 */
    572