lib/regex.h

   1 /* Definitions for data structures and routines for the regular
   2    expression library.
   3    Copyright (C) 1985, 1989-1993, 1995-1998, 2000-2003, 2005-2012
   4    Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU Lesser General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    This program 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
  15    GNU Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public License along
  18    with this program; if not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _REGEX_H
  21 #define _REGEX_H 1
  22
  23 #include <sys/types.h>
  24
  25 /* Allow the use in C++ code.  */
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 /* Define __USE_GNU to declare GNU extensions that violate the
  31    POSIX name space rules.  */
  32 #ifdef _GNU_SOURCE
  33 # define __USE_GNU 1
  34 #endif
  35
  36 #ifdef _REGEX_LARGE_OFFSETS
  37
  38 /* Use types and values that are wide enough to represent signed and
  39    unsigned byte offsets in memory.  This currently works only when
  40    the regex code is used outside of the GNU C library; it is not yet
  41    supported within glibc itself, and glibc users should not define
  42    _REGEX_LARGE_OFFSETS.  */
  43
  44 /* The type of nonnegative object indexes.  Traditionally, GNU regex
  45    uses 'int' for these.  Code that uses __re_idx_t should work
  46    regardless of whether the type is signed.  */
  47 typedef size_t __re_idx_t;
  48
  49 /* The type of object sizes.  */
  50 typedef size_t __re_size_t;
  51
  52 /* The type of object sizes, in places where the traditional code
  53    uses unsigned long int.  */
  54 typedef size_t __re_long_size_t;
  55
  56 #else
  57
  58 /* The traditional GNU regex implementation mishandles strings longer
  59    than INT_MAX.  */
  60 typedef int __re_idx_t;
  61 typedef unsigned int __re_size_t;
  62 typedef unsigned long int __re_long_size_t;
  63
  64 #endif
  65
  66 /* The following two types have to be signed and unsigned integer type
  67    wide enough to hold a value of a pointer.  For most ANSI compilers
  68    ptrdiff_t and size_t should be likely OK.  Still size of these two
  69    types is 2 for Microsoft C.  Ugh... */
  70 typedef long int s_reg_t;
  71 typedef unsigned long int active_reg_t;
  72
  73 /* The following bits are used to determine the regexp syntax we
  74    recognize.  The set/not-set meanings are chosen so that Emacs syntax
  75    remains the value 0.  The bits are given in alphabetical order, and
  76    the definitions shifted by one from the previous bit; thus, when we
  77    add or remove a bit, only one other definition need change.  */
  78 typedef unsigned long int reg_syntax_t;
  79
  80 #ifdef __USE_GNU
  81 /* If this bit is not set, then \ inside a bracket expression is literal.
  82    If set, then such a \ quotes the following character.  */
  83 # define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
  84
  85 /* If this bit is not set, then + and ? are operators, and \+ and \? are
  86      literals.
  87    If set, then \+ and \? are operators and + and ? are literals.  */
  88 # define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
  89
  90 /* If this bit is set, then character classes are supported.  They are:
  91      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
  92      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
  93    If not set, then character classes are not supported.  */
  94 # define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
  95
  96 /* If this bit is set, then ^ and $ are always anchors (outside bracket
  97      expressions, of course).
  98    If this bit is not set, then it depends:
  99         ^  is an anchor if it is at the beginning of a regular
 100            expression or after an open-group or an alternation operator;
 101         $  is an anchor if it is at the end of a regular expression, or
 102            before a close-group or an alternation operator.
 103
 104    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
 105    POSIX draft 11.2 says that * etc. in leading positions is undefined.
 106    We already implemented a previous draft which made those constructs
 107    invalid, though, so we haven't changed the code back.  */
 108 # define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
 109
 110 /* If this bit is set, then special characters are always special
 111      regardless of where they are in the pattern.
 112    If this bit is not set, then special characters are special only in
 113      some contexts; otherwise they are ordinary.  Specifically,
 114      * + ? and intervals are only special when not after the beginning,
 115      open-group, or alternation operator.  */
 116 # define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
 117
 118 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
 119      immediately after an alternation or begin-group operator.  */
 120 # define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
 121
 122 /* If this bit is set, then . matches newline.
 123    If not set, then it doesn't.  */
 124 # define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
 125
 126 /* If this bit is set, then . doesn't match NUL.
 127    If not set, then it does.  */
 128 # define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
 129
 130 /* If this bit is set, nonmatching lists [^...] do not match newline.
 131    If not set, they do.  */
 132 # define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
 133
 134 /* If this bit is set, either \{...\} or {...} defines an
 135      interval, depending on RE_NO_BK_BRACES.
 136    If not set, \{, \}, {, and } are literals.  */
 137 # define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
 138
 139 /* If this bit is set, +, ? and | aren't recognized as operators.
 140    If not set, they are.  */
 141 # define RE_LIMITED_OPS (RE_INTERVALS << 1)
 142
 143 /* If this bit is set, newline is an alternation operator.
 144    If not set, newline is literal.  */
 145 # define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
 146
 147 /* If this bit is set, then '{...}' defines an interval, and \{ and \}
 148      are literals.
 149   If not set, then '\{...\}' defines an interval.  */
 150 # define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
 151
 152 /* If this bit is set, (...) defines a group, and \( and \) are literals.
 153    If not set, \(...\) defines a group, and ( and ) are literals.  */
 154 # define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
 155
 156 /* If this bit is set, then \<digit> matches <digit>.
 157    If not set, then \<digit> is a back-reference.  */
 158 # define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
 159
 160 /* If this bit is set, then | is an alternation operator, and \| is literal.
 161    If not set, then \| is an alternation operator, and | is literal.  */
 162 # define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
 163
 164 /* If this bit is set, then an ending range point collating higher
 165      than the starting range point, as in [z-a], is invalid.
 166    If not set, then when ending range point collates higher than the
 167      starting range point, the range is ignored.  */
 168 # define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
 169
 170 /* If this bit is set, then an unmatched ) is ordinary.
 171    If not set, then an unmatched ) is invalid.  */
 172 # define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
 173
 174 /* If this bit is set, succeed as soon as we match the whole pattern,
 175    without further backtracking.  */
 176 # define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
 177
 178 /* If this bit is set, do not process the GNU regex operators.
 179    If not set, then the GNU regex operators are recognized. */
 180 # define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
 181
 182 /* If this bit is set, turn on internal regex debugging.
 183    If not set, and debugging was on, turn it off.
 184    This only works if regex.c is compiled -DDEBUG.
 185    We define this bit always, so that all that's needed to turn on
 186    debugging is to recompile regex.c; the calling code can always have
 187    this bit set, and it won't affect anything in the normal case. */
 188 # define RE_DEBUG (RE_NO_GNU_OPS << 1)
 189
 190 /* If this bit is set, a syntactically invalid interval is treated as
 191    a string of ordinary characters.  For example, the ERE 'a{1' is
 192    treated as 'a\{1'.  */
 193 # define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
 194
 195 /* If this bit is set, then ignore case when matching.
 196    If not set, then case is significant.  */
 197 # define RE_ICASE (RE_INVALID_INTERVAL_ORD << 1)
 198
 199 /* This bit is used internally like RE_CONTEXT_INDEP_ANCHORS but only
 200    for ^, because it is difficult to scan the regex backwards to find
 201    whether ^ should be special.  */
 202 # define RE_CARET_ANCHORS_HERE (RE_ICASE << 1)
 203
 204 /* If this bit is set, then \{ cannot be first in a regex or
 205    immediately after an alternation, open-group or \} operator.  */
 206 # define RE_CONTEXT_INVALID_DUP (RE_CARET_ANCHORS_HERE << 1)
 207
 208 /* If this bit is set, then no_sub will be set to 1 during
 209    re_compile_pattern.  */
 210 # define RE_NO_SUB (RE_CONTEXT_INVALID_DUP << 1)
 211 #endif
 212
 213 /* This global variable defines the particular regexp syntax to use (for
 214    some interfaces).  When a regexp is compiled, the syntax used is
 215    stored in the pattern buffer, so changing this does not affect
 216    already-compiled regexps.  */
 217 extern reg_syntax_t re_syntax_options;
 218 \f
 219 #ifdef __USE_GNU
 220 /* Define combinations of the above bits for the standard possibilities.
 221    (The [[[ comments delimit what gets put into the Texinfo file, so
 222    don't delete them!)  */
 223 /* [[[begin syntaxes]]] */
 224 # define RE_SYNTAX_EMACS 0
 225
 226 # define RE_SYNTAX_AWK                                                  \
 227   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                     \
 228    | RE_NO_BK_PARENS              | RE_NO_BK_REFS                       \
 229    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                  \
 230    | RE_DOT_NEWLINE               | RE_CONTEXT_INDEP_ANCHORS            \
 231    | RE_CHAR_CLASSES                                                    \
 232    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
 233
 234 # define RE_SYNTAX_GNU_AWK                                              \
 235   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS             \
 236     | RE_INVALID_INTERVAL_ORD)                                          \
 237    & ~(RE_DOT_NOT_NULL | RE_CONTEXT_INDEP_OPS                           \
 238       | RE_CONTEXT_INVALID_OPS ))
 239
 240 # define RE_SYNTAX_POSIX_AWK                                            \
 241   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS              \
 242    | RE_INTERVALS           | RE_NO_GNU_OPS                             \
 243    | RE_INVALID_INTERVAL_ORD)
 244
 245 # define RE_SYNTAX_GREP                                                 \
 246   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
 247    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
 248    | RE_NEWLINE_ALT)
 249
 250 # define RE_SYNTAX_EGREP                                                \
 251   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
 252    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
 253    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
 254    | RE_NO_BK_VBAR)
 255
 256 # define RE_SYNTAX_POSIX_EGREP                                          \
 257   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES                     \
 258    | RE_INVALID_INTERVAL_ORD)
 259
 260 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
 261 # define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
 262
 263 # define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
 264
 265 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
 266 # define _RE_SYNTAX_POSIX_COMMON                                        \
 267   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
 268    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
 269
 270 # define RE_SYNTAX_POSIX_BASIC                                          \
 271   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM | RE_CONTEXT_INVALID_DUP)
 272
 273 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
 274    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
 275    isn't minimal, since other operators, such as \`, aren't disabled.  */
 276 # define RE_SYNTAX_POSIX_MINIMAL_BASIC                                  \
 277   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
 278
 279 # define RE_SYNTAX_POSIX_EXTENDED                                       \
 280   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 281    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                           \
 282    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                             \
 283    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
 284
 285 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
 286    removed and RE_NO_BK_REFS is added.  */
 287 # define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                               \
 288   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 289    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
 290    | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
 291    | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)
 292 /* [[[end syntaxes]]] */
 293
 294 /* Maximum number of duplicates an interval can allow.  POSIX-conforming
 295    systems might define this in <limits.h>, but we want our
 296    value, so remove any previous define.  */
 297 # ifdef _REGEX_INCLUDE_LIMITS_H
 298 #  include <limits.h>
 299 # endif
 300 # ifdef RE_DUP_MAX
 301 #  undef RE_DUP_MAX
 302 # endif
 303
 304 /* RE_DUP_MAX is 2**15 - 1 because an earlier implementation stored
 305    the counter as a 2-byte signed integer.  This is no longer true, so
 306    RE_DUP_MAX could be increased to (INT_MAX / 10 - 1), or to
 307    ((SIZE_MAX - 9) / 10) if _REGEX_LARGE_OFFSETS is defined.
 308    However, there would be a huge performance problem if someone
 309    actually used a pattern like a\{214748363\}, so RE_DUP_MAX retains
 310    its historical value.  */
 311 # define RE_DUP_MAX (0x7fff)
 312 #endif
 313
 314
 315 /* POSIX 'cflags' bits (i.e., information for 'regcomp').  */
 316
 317 /* If this bit is set, then use extended regular expression syntax.
 318    If not set, then use basic regular expression syntax.  */
 319 #define REG_EXTENDED 1
 320
 321 /* If this bit is set, then ignore case when matching.
 322    If not set, then case is significant.  */
 323 #define REG_ICASE (1 << 1)
 324
 325 /* If this bit is set, then anchors do not match at newline
 326      characters in the string.
 327    If not set, then anchors do match at newlines.  */
 328 #define REG_NEWLINE (1 << 2)
 329
 330 /* If this bit is set, then report only success or fail in regexec.
 331    If not set, then returns differ between not matching and errors.  */
 332 #define REG_NOSUB (1 << 3)
 333
 334
 335 /* POSIX 'eflags' bits (i.e., information for regexec).  */
 336
 337 /* If this bit is set, then the beginning-of-line operator doesn't match
 338      the beginning of the string (presumably because it's not the
 339      beginning of a line).
 340    If not set, then the beginning-of-line operator does match the
 341      beginning of the string.  */
 342 #define REG_NOTBOL 1
 343
 344 /* Like REG_NOTBOL, except for the end-of-line.  */
 345 #define REG_NOTEOL (1 << 1)
 346
 347 /* Use PMATCH[0] to delimit the start and end of the search in the
 348    buffer.  */
 349 #define REG_STARTEND (1 << 2)
 350
 351
 352 /* If any error codes are removed, changed, or added, update the
 353    '__re_error_msgid' table in regcomp.c.  */
 354
 355 typedef enum
 356 {
 357   _REG_ENOSYS = -1,     /* This will never happen for this implementation.  */
 358   _REG_NOERROR = 0,     /* Success.  */
 359   _REG_NOMATCH,         /* Didn't find a match (for regexec).  */
 360
 361   /* POSIX regcomp return error codes.  (In the order listed in the
 362      standard.)  */
 363   _REG_BADPAT,          /* Invalid pattern.  */
 364   _REG_ECOLLATE,        /* Invalid collating element.  */
 365   _REG_ECTYPE,          /* Invalid character class name.  */
 366   _REG_EESCAPE,         /* Trailing backslash.  */
 367   _REG_ESUBREG,         /* Invalid back reference.  */
 368   _REG_EBRACK,          /* Unmatched left bracket.  */
 369   _REG_EPAREN,          /* Parenthesis imbalance.  */
 370   _REG_EBRACE,          /* Unmatched \{.  */
 371   _REG_BADBR,           /* Invalid contents of \{\}.  */
 372   _REG_ERANGE,          /* Invalid range end.  */
 373   _REG_ESPACE,          /* Ran out of memory.  */
 374   _REG_BADRPT,          /* No preceding re for repetition op.  */
 375
 376   /* Error codes we've added.  */
 377   _REG_EEND,            /* Premature end.  */
 378   _REG_ESIZE,           /* Too large (e.g., repeat count too large).  */
 379   _REG_ERPAREN          /* Unmatched ) or \); not returned from regcomp.  */
 380 } reg_errcode_t;
 381
 382 #if defined _XOPEN_SOURCE || defined __USE_XOPEN2K
 383 # define REG_ENOSYS     _REG_ENOSYS
 384 #endif
 385 #define REG_NOERROR     _REG_NOERROR
 386 #define REG_NOMATCH     _REG_NOMATCH
 387 #define REG_BADPAT      _REG_BADPAT
 388 #define REG_ECOLLATE    _REG_ECOLLATE
 389 #define REG_ECTYPE      _REG_ECTYPE
 390 #define REG_EESCAPE     _REG_EESCAPE
 391 #define REG_ESUBREG     _REG_ESUBREG
 392 #define REG_EBRACK      _REG_EBRACK
 393 #define REG_EPAREN      _REG_EPAREN
 394 #define REG_EBRACE      _REG_EBRACE
 395 #define REG_BADBR       _REG_BADBR
 396 #define REG_ERANGE      _REG_ERANGE
 397 #define REG_ESPACE      _REG_ESPACE
 398 #define REG_BADRPT      _REG_BADRPT
 399 #define REG_EEND        _REG_EEND
 400 #define REG_ESIZE       _REG_ESIZE
 401 #define REG_ERPAREN     _REG_ERPAREN
 402 \f
 403 /* This data structure represents a compiled pattern.  Before calling
 404    the pattern compiler, the fields 'buffer', 'allocated', 'fastmap',
 405    and 'translate' can be set.  After the pattern has been compiled,
 406    the fields 're_nsub', 'not_bol' and 'not_eol' are available.  All
 407    other fields are private to the regex routines.  */
 408
 409 #ifndef RE_TRANSLATE_TYPE
 410 # define __RE_TRANSLATE_TYPE unsigned char *
 411 # ifdef __USE_GNU
 412 #  define RE_TRANSLATE_TYPE __RE_TRANSLATE_TYPE
 413 # endif
 414 #endif
 415
 416 #ifdef __USE_GNU
 417 # define __REPB_PREFIX(name) name
 418 #else
 419 # define __REPB_PREFIX(name) __##name
 420 #endif
 421
 422 struct re_pattern_buffer
 423 {
 424   /* Space that holds the compiled pattern.  The type
 425      'struct re_dfa_t' is private and is not declared here.  */
 426   struct re_dfa_t *__REPB_PREFIX(buffer);
 427
 428   /* Number of bytes to which 'buffer' points.  */
 429   __re_long_size_t __REPB_PREFIX(allocated);
 430
 431   /* Number of bytes actually used in 'buffer'.  */
 432   __re_long_size_t __REPB_PREFIX(used);
 433
 434   /* Syntax setting with which the pattern was compiled.  */
 435   reg_syntax_t __REPB_PREFIX(syntax);
 436
 437   /* Pointer to a fastmap, if any, otherwise zero.  re_search uses the
 438      fastmap, if there is one, to skip over impossible starting points
 439      for matches.  */
 440   char *__REPB_PREFIX(fastmap);
 441
 442   /* Either a translate table to apply to all characters before
 443      comparing them, or zero for no translation.  The translation is
 444      applied to a pattern when it is compiled and to a string when it
 445      is matched.  */
 446   __RE_TRANSLATE_TYPE __REPB_PREFIX(translate);
 447
 448   /* Number of subexpressions found by the compiler.  */
 449   size_t re_nsub;
 450
 451   /* Zero if this pattern cannot match the empty string, one else.
 452      Well, in truth it's used only in 're_search_2', to see whether or
 453      not we should use the fastmap, so we don't set this absolutely
 454      perfectly; see 're_compile_fastmap' (the "duplicate" case).  */
 455   unsigned __REPB_PREFIX(can_be_null) : 1;
 456
 457   /* If REGS_UNALLOCATED, allocate space in the 'regs' structure
 458      for 'max (RE_NREGS, re_nsub + 1)' groups.
 459      If REGS_REALLOCATE, reallocate space if necessary.
 460      If REGS_FIXED, use what's there.  */
 461 #ifdef __USE_GNU
 462 # define REGS_UNALLOCATED 0
 463 # define REGS_REALLOCATE 1
 464 # define REGS_FIXED 2
 465 #endif
 466   unsigned __REPB_PREFIX(regs_allocated) : 2;
 467
 468   /* Set to zero when 're_compile_pattern' compiles a pattern; set to
 469      one by 're_compile_fastmap' if it updates the fastmap.  */
 470   unsigned __REPB_PREFIX(fastmap_accurate) : 1;
 471
 472   /* If set, 're_match_2' does not return information about
 473      subexpressions.  */
 474   unsigned __REPB_PREFIX(no_sub) : 1;
 475
 476   /* If set, a beginning-of-line anchor doesn't match at the beginning
 477      of the string.  */
 478   unsigned __REPB_PREFIX(not_bol) : 1;
 479
 480   /* Similarly for an end-of-line anchor.  */
 481   unsigned __REPB_PREFIX(not_eol) : 1;
 482
 483   /* If true, an anchor at a newline matches.  */
 484   unsigned __REPB_PREFIX(newline_anchor) : 1;
 485 };
 486
 487 typedef struct re_pattern_buffer regex_t;
 488 \f
 489 /* Type for byte offsets within the string.  POSIX mandates this.  */
 490 #ifdef _REGEX_LARGE_OFFSETS
 491 /* POSIX 1003.1-2008 requires that regoff_t be at least as wide as
 492    ptrdiff_t and ssize_t.  We don't know of any hosts where ptrdiff_t
 493    is wider than ssize_t, so ssize_t is safe.  */
 494 typedef ssize_t regoff_t;
 495 #else
 496 /* The traditional GNU regex implementation mishandles strings longer
 497    than INT_MAX.  */
 498 typedef int regoff_t;
 499 #endif
 500
 501
 502 #ifdef __USE_GNU
 503 /* This is the structure we store register match data in.  See
 504    regex.texinfo for a full description of what registers match.  */
 505 struct re_registers
 506 {
 507   __re_size_t num_regs;
 508   regoff_t *start;
 509   regoff_t *end;
 510 };
 511
 512
 513 /* If 'regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
 514    're_match_2' returns information about at least this many registers
 515    the first time a 'regs' structure is passed.  */
 516 # ifndef RE_NREGS
 517 #  define RE_NREGS 30
 518 # endif
 519 #endif
 520
 521
 522 /* POSIX specification for registers.  Aside from the different names than
 523    're_registers', POSIX uses an array of structures, instead of a
 524    structure of arrays.  */
 525 typedef struct
 526 {
 527   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
 528   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
 529 } regmatch_t;
 530 \f
 531 /* Declarations for routines.  */
 532
 533 #ifdef __USE_GNU
 534 /* Sets the current default syntax to SYNTAX, and return the old syntax.
 535    You can also simply assign to the 're_syntax_options' variable.  */
 536 extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax);
 537
 538 /* Compile the regular expression PATTERN, with length LENGTH
 539    and syntax given by the global 're_syntax_options', into the buffer
 540    BUFFER.  Return NULL if successful, and an error string if not.
 541
 542    To free the allocated storage, you must call 'regfree' on BUFFER.
 543    Note that the translate table must either have been initialised by
 544    'regcomp', with a malloc'ed value, or set to NULL before calling
 545    'regfree'.  */
 546 extern const char *re_compile_pattern (const char *__pattern, size_t __length,
 547                                        struct re_pattern_buffer *__buffer);
 548
 549
 550 /* Compile a fastmap for the compiled pattern in BUFFER; used to
 551    accelerate searches.  Return 0 if successful and -2 if was an
 552    internal error.  */
 553 extern int re_compile_fastmap (struct re_pattern_buffer *__buffer);
 554
 555
 556 /* Search in the string STRING (with length LENGTH) for the pattern
 557    compiled into BUFFER.  Start searching at position START, for RANGE
 558    characters.  Return the starting position of the match, -1 for no
 559    match, or -2 for an internal error.  Also return register
 560    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
 561 extern regoff_t re_search (struct re_pattern_buffer *__buffer,
 562                            const char *__string, __re_idx_t __length,
 563                            __re_idx_t __start, regoff_t __range,
 564                            struct re_registers *__regs);
 565
 566
 567 /* Like 're_search', but search in the concatenation of STRING1 and
 568    STRING2.  Also, stop searching at index START + STOP.  */
 569 extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer,
 570                              const char *__string1, __re_idx_t __length1,
 571                              const char *__string2, __re_idx_t __length2,
 572                              __re_idx_t __start, regoff_t __range,
 573                              struct re_registers *__regs,
 574                              __re_idx_t __stop);
 575
 576
 577 /* Like 're_search', but return how many characters in STRING the regexp
 578    in BUFFER matched, starting at position START.  */
 579 extern regoff_t re_match (struct re_pattern_buffer *__buffer,
 580                           const char *__string, __re_idx_t __length,
 581                           __re_idx_t __start, struct re_registers *__regs);
 582
 583
 584 /* Relates to 're_match' as 're_search_2' relates to 're_search'.  */
 585 extern regoff_t re_match_2 (struct re_pattern_buffer *__buffer,
 586                             const char *__string1, __re_idx_t __length1,
 587                             const char *__string2, __re_idx_t __length2,
 588                             __re_idx_t __start, struct re_registers *__regs,
 589                             __re_idx_t __stop);
 590
 591
 592 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
 593    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
 594    for recording register information.  STARTS and ENDS must be
 595    allocated with malloc, and must each be at least 'NUM_REGS * sizeof
 596    (regoff_t)' bytes long.
 597
 598    If NUM_REGS == 0, then subsequent matches should allocate their own
 599    register data.
 600
 601    Unless this function is called, the first search or match using
 602    BUFFER will allocate its own register data, without
 603    freeing the old data.  */
 604 extern void re_set_registers (struct re_pattern_buffer *__buffer,
 605                               struct re_registers *__regs,
 606                               __re_size_t __num_regs,
 607                               regoff_t *__starts, regoff_t *__ends);
 608 #endif  /* Use GNU */
 609
 610 #if defined _REGEX_RE_COMP || (defined _LIBC && defined __USE_BSD)
 611 # ifndef _CRAY
 612 /* 4.2 bsd compatibility.  */
 613 extern char *re_comp (const char *);
 614 extern int re_exec (const char *);
 615 # endif
 616 #endif
 617
 618 /* GCC 2.95 and later have "__restrict"; C99 compilers have
 619    "restrict", and "configure" may have defined "restrict".
 620    Other compilers use __restrict, __restrict__, and _Restrict, and
 621    'configure' might #define 'restrict' to those words, so pick a
 622    different name.  */
 623 #ifndef _Restrict_
 624 # if 199901L <= __STDC_VERSION__
 625 #  define _Restrict_ restrict
 626 # elif 2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__)
 627 #  define _Restrict_ __restrict
 628 # else
 629 #  define _Restrict_
 630 # endif
 631 #endif
 632 /* gcc 3.1 and up support the [restrict] syntax.  Don't trust
 633    sys/cdefs.h's definition of __restrict_arr, though, as it
 634    mishandles gcc -ansi -pedantic.  */
 635 #ifndef _Restrict_arr_
 636 # if ((199901L <= __STDC_VERSION__                                      \
 637        || ((3 < __GNUC__ || (3 == __GNUC__ && 1 <= __GNUC_MINOR__))     \
 638            && !defined __STRICT_ANSI__))                                        \
 639       && !defined __GNUG__)
 640 #  define _Restrict_arr_ _Restrict_
 641 # else
 642 #  define _Restrict_arr_
 643 # endif
 644 #endif
 645
 646 /* POSIX compatibility.  */
 647 extern int regcomp (regex_t *_Restrict_ __preg,
 648                     const char *_Restrict_ __pattern,
 649                     int __cflags);
 650
 651 extern int regexec (const regex_t *_Restrict_ __preg,
 652                     const char *_Restrict_ __string, size_t __nmatch,
 653                     regmatch_t __pmatch[_Restrict_arr_],
 654                     int __eflags);
 655
 656 extern size_t regerror (int __errcode, const regex_t *_Restrict_ __preg,
 657                         char *_Restrict_ __errbuf, size_t __errbuf_size);
 658
 659 extern void regfree (regex_t *__preg);
 660
 661
 662 #ifdef __cplusplus
 663 }
 664 #endif  /* C++ */
 665
 666 #endif /* regex.h */