comparison src/regex.h @ 0:376386a54a3c r19-14

Import from CVS: tag r19-14
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date Mon, 13 Aug 2007 08:45:50 +0200
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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, 89, 90, 91, 92, 93, 95 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; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
20
21 /* Synched up with: FSF 19.29. */
22
23 #ifndef __REGEXP_LIBRARY_H__
24 #define __REGEXP_LIBRARY_H__
25
26 /* POSIX says that <sys/types.h> must be included (by the caller) before
27 <regex.h>. */
28
29 #if !defined (_POSIX_C_SOURCE) && !defined (_POSIX_SOURCE) && defined (VMS)
30 /* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
31 should be there. */
32 #include <stddef.h>
33 #endif
34
35
36 /* The following bits are used to determine the regexp syntax we
37 recognize. The set/not-set meanings are chosen so that Emacs syntax
38 remains the value 0. The bits are given in alphabetical order, and
39 the definitions shifted by one from the previous bit; thus, when we
40 add or remove a bit, only one other definition need change. */
41 typedef unsigned reg_syntax_t;
42
43 /* If this bit is not set, then \ inside a bracket expression is literal.
44 If set, then such a \ quotes the following character. */
45 #define RE_BACKSLASH_ESCAPE_IN_LISTS (1)
46
47 /* If this bit is not set, then + and ? are operators, and \+ and \? are
48 literals.
49 If set, then \+ and \? are operators and + and ? are literals. */
50 #define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
51
52 /* If this bit is set, then character classes are supported. They are:
53 [:alpha:], [:upper:], [:lower:], [:digit:], [:alnum:], [:xdigit:],
54 [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
55 If not set, then character classes are not supported. */
56 #define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
57
58 /* If this bit is set, then ^ and $ are always anchors (outside bracket
59 expressions, of course).
60 If this bit is not set, then it depends:
61 ^ is an anchor if it is at the beginning of a regular
62 expression or after an open-group or an alternation operator;
63 $ is an anchor if it is at the end of a regular expression, or
64 before a close-group or an alternation operator.
65
66 This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
67 POSIX draft 11.2 says that * etc. in leading positions is undefined.
68 We already implemented a previous draft which made those constructs
69 invalid, though, so we haven't changed the code back. */
70 #define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
71
72 /* If this bit is set, then special characters are always special
73 regardless of where they are in the pattern.
74 If this bit is not set, then special characters are special only in
75 some contexts; otherwise they are ordinary. Specifically,
76 * + ? and intervals are only special when not after the beginning,
77 open-group, or alternation operator. */
78 #define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
79
80 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
81 immediately after an alternation or begin-group operator. */
82 #define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
83
84 /* If this bit is set, then . matches newline.
85 If not set, then it doesn't. */
86 #define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
87
88 /* If this bit is set, then . doesn't match NUL.
89 If not set, then it does. */
90 #define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
91
92 /* If this bit is set, nonmatching lists [^...] do not match newline.
93 If not set, they do. */
94 #define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
95
96 /* If this bit is set, either \{...\} or {...} defines an
97 interval, depending on RE_NO_BK_BRACES.
98 If not set, \{, \}, {, and } are literals. */
99 #define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
100
101 /* If this bit is set, +, ? and | aren't recognized as operators.
102 If not set, they are. */
103 #define RE_LIMITED_OPS (RE_INTERVALS << 1)
104
105 /* If this bit is set, newline is an alternation operator.
106 If not set, newline is literal. */
107 #define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
108
109 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
110 are literals.
111 If not set, then `\{...\}' defines an interval. */
112 #define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
113
114 /* If this bit is set, (...) defines a group, and \( and \) are literals.
115 If not set, \(...\) defines a group, and ( and ) are literals. */
116 #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
117
118 /* If this bit is set, then \<digit> matches <digit>.
119 If not set, then \<digit> is a back-reference. */
120 #define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
121
122 /* If this bit is set, then | is an alternation operator, and \| is literal.
123 If not set, then \| is an alternation operator, and | is literal. */
124 #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
125
126 /* If this bit is set, then an ending range point collating higher
127 than the starting range point, as in [z-a], is invalid.
128 If not set, then when ending range point collates higher than the
129 starting range point, the range is ignored. */
130 #define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
131
132 /* If this bit is set, then an unmatched ) is ordinary.
133 If not set, then an unmatched ) is invalid. */
134 #define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
135
136 /* If this bit is set, succeed as soon as we match the whole pattern,
137 without further backtracking. */
138 #define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
139
140 /* This global variable defines the particular regexp syntax to use (for
141 some interfaces). When a regexp is compiled, the syntax used is
142 stored in the pattern buffer, so changing this does not affect
143 already-compiled regexps. */
144 extern reg_syntax_t re_syntax_options;
145
146 /* Define combinations of the above bits for the standard possibilities.
147 (The [[[ comments delimit what gets put into the Texinfo file, so
148 don't delete them!) */
149 /* [[[begin syntaxes]]] */
150 #define RE_SYNTAX_EMACS 0
151
152 #define RE_SYNTAX_AWK \
153 (RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DOT_NOT_NULL \
154 | RE_NO_BK_PARENS | RE_NO_BK_REFS \
155 | RE_NO_BK_VBAR | RE_NO_EMPTY_RANGES \
156 | RE_UNMATCHED_RIGHT_PAREN_ORD)
157
158 #define RE_SYNTAX_POSIX_AWK \
159 (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS)
160
161 #define RE_SYNTAX_GREP \
162 (RE_BK_PLUS_QM | RE_CHAR_CLASSES \
163 | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS \
164 | RE_NEWLINE_ALT)
165
166 #define RE_SYNTAX_EGREP \
167 (RE_CHAR_CLASSES | RE_CONTEXT_INDEP_ANCHORS \
168 | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE \
169 | RE_NEWLINE_ALT | RE_NO_BK_PARENS \
170 | RE_NO_BK_VBAR)
171
172 #define RE_SYNTAX_POSIX_EGREP \
173 (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES)
174
175 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff. */
176 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
177
178 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
179
180 /* Syntax bits common to both basic and extended POSIX regex syntax. */
181 #define _RE_SYNTAX_POSIX_COMMON \
182 (RE_CHAR_CLASSES | RE_DOT_NEWLINE | RE_DOT_NOT_NULL \
183 | RE_INTERVALS | RE_NO_EMPTY_RANGES)
184
185 #define RE_SYNTAX_POSIX_BASIC \
186 (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
187
188 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
189 RE_LIMITED_OPS, i.e., \? \+ \| are not recognized. Actually, this
190 isn't minimal, since other operators, such as \`, aren't disabled. */
191 #define RE_SYNTAX_POSIX_MINIMAL_BASIC \
192 (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
193
194 #define RE_SYNTAX_POSIX_EXTENDED \
195 (_RE_SYNTAX_POSIX_COMMON | RE_CONTEXT_INDEP_ANCHORS \
196 | RE_CONTEXT_INDEP_OPS | RE_NO_BK_BRACES \
197 | RE_NO_BK_PARENS | RE_NO_BK_VBAR \
198 | RE_UNMATCHED_RIGHT_PAREN_ORD)
199
200 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INVALID_OPS
201 replaces RE_CONTEXT_INDEP_OPS and RE_NO_BK_REFS is added. */
202 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED \
203 (_RE_SYNTAX_POSIX_COMMON | RE_CONTEXT_INDEP_ANCHORS \
204 | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES \
205 | RE_NO_BK_PARENS | RE_NO_BK_REFS \
206 | RE_NO_BK_VBAR | RE_UNMATCHED_RIGHT_PAREN_ORD)
207 /* [[[end syntaxes]]] */
208
209 /* Maximum number of duplicates an interval can allow. Some systems
210 (erroneously) define this in other header files, but we want our
211 value, so remove any previous define. */
212 #ifdef RE_DUP_MAX
213 #undef RE_DUP_MAX
214 #endif
215 #define RE_DUP_MAX ((1 << 15) - 1)
216
217
218 /* POSIX `cflags' bits (i.e., information for `regcomp'). */
219
220 /* If this bit is set, then use extended regular expression syntax.
221 If not set, then use basic regular expression syntax. */
222 #define REG_EXTENDED 1
223
224 /* If this bit is set, then ignore case when matching.
225 If not set, then case is significant. */
226 #define REG_ICASE (REG_EXTENDED << 1)
227
228 /* If this bit is set, then anchors do not match at newline
229 characters in the string.
230 If not set, then anchors do match at newlines. */
231 #define REG_NEWLINE (REG_ICASE << 1)
232
233 /* If this bit is set, then report only success or fail in regexec.
234 If not set, then returns differ between not matching and errors. */
235 #define REG_NOSUB (REG_NEWLINE << 1)
236
237
238 /* POSIX `eflags' bits (i.e., information for regexec). */
239
240 /* If this bit is set, then the beginning-of-line operator doesn't match
241 the beginning of the string (presumably because it's not the
242 beginning of a line).
243 If not set, then the beginning-of-line operator does match the
244 beginning of the string. */
245 #define REG_NOTBOL 1
246
247 /* Like REG_NOTBOL, except for the end-of-line. */
248 #define REG_NOTEOL (1 << 1)
249
250
251 /* If any error codes are removed, changed, or added, update the
252 `re_error_msg' table in regex.c. */
253 typedef enum
254 {
255 REG_NOERROR = 0, /* Success. */
256 REG_NOMATCH, /* Didn't find a match (for regexec). */
257
258 /* POSIX regcomp return error codes. (In the order listed in the
259 standard.) */
260 REG_BADPAT, /* Invalid pattern. */
261 REG_ECOLLATE, /* Not implemented. */
262 REG_ECTYPE, /* Invalid character class name. */
263 REG_EESCAPE, /* Trailing backslash. */
264 REG_ESUBREG, /* Invalid back reference. */
265 REG_EBRACK, /* Unmatched left bracket. */
266 REG_EPAREN, /* Parenthesis imbalance. */
267 REG_EBRACE, /* Unmatched \{. */
268 REG_BADBR, /* Invalid contents of \{\}. */
269 REG_ERANGE, /* Invalid range end. */
270 REG_ESPACE, /* Ran out of memory. */
271 REG_BADRPT, /* No preceding re for repetition op. */
272
273 /* Error codes we've added. */
274 REG_EEND, /* Premature end. */
275 REG_ESIZE, /* Compiled pattern bigger than 2^16 bytes. */
276 REG_ERPAREN /* Unmatched ) or \); not returned from regcomp. */
277 #ifdef emacs
278 ,REG_ESYNTAX /* Invalid syntax designator. */
279 #endif
280 } reg_errcode_t;
281
282 /* This data structure represents a compiled pattern. Before calling
283 the pattern compiler, the fields `buffer', `allocated', `fastmap',
284 `translate', and `no_sub' can be set. After the pattern has been
285 compiled, the `re_nsub' field is available. All other fields are
286 private to the regex routines. */
287
288 struct re_pattern_buffer
289 {
290 /* [[[begin pattern_buffer]]] */
291 /* Space that holds the compiled pattern. It is declared as
292 `unsigned char *' because its elements are
293 sometimes used as array indexes. */
294 unsigned char *buffer;
295
296 /* Number of bytes to which `buffer' points. */
297 unsigned long allocated;
298
299 /* Number of bytes actually used in `buffer'. */
300 unsigned long used;
301
302 /* Syntax setting with which the pattern was compiled. */
303 reg_syntax_t syntax;
304
305 /* Pointer to a fastmap, if any, otherwise zero. re_search uses
306 the fastmap, if there is one, to skip over impossible
307 starting points for matches. */
308 char *fastmap;
309
310 /* Either a translate table to apply to all characters before
311 comparing them, or zero for no translation. The translation
312 is applied to a pattern when it is compiled and to a string
313 when it is matched. */
314 char *translate;
315
316 /* Number of subexpressions found by the compiler. */
317 size_t re_nsub;
318
319 /* Zero if this pattern cannot match the empty string, one else.
320 Well, in truth it's used only in `re_search_2', to see
321 whether or not we should use the fastmap, so we don't set
322 this absolutely perfectly; see `re_compile_fastmap' (the
323 `duplicate' case). */
324 unsigned can_be_null : 1;
325
326 /* If REGS_UNALLOCATED, allocate space in the `regs' structure
327 for `max (RE_NREGS, re_nsub + 1)' groups.
328 If REGS_REALLOCATE, reallocate space if necessary.
329 If REGS_FIXED, use what's there. */
330 #define REGS_UNALLOCATED 0
331 #define REGS_REALLOCATE 1
332 #define REGS_FIXED 2
333 unsigned regs_allocated : 2;
334
335 /* Set to zero when `regex_compile' compiles a pattern; set to one
336 by `re_compile_fastmap' if it updates the fastmap. */
337 unsigned fastmap_accurate : 1;
338
339 /* If set, `re_match_2' does not return information about
340 subexpressions. */
341 unsigned no_sub : 1;
342
343 /* If set, a beginning-of-line anchor doesn't match at the
344 beginning of the string. */
345 unsigned not_bol : 1;
346
347 /* Similarly for an end-of-line anchor. */
348 unsigned not_eol : 1;
349
350 /* If true, an anchor at a newline matches. */
351 unsigned newline_anchor : 1;
352
353 /* [[[end pattern_buffer]]] */
354 };
355
356 typedef struct re_pattern_buffer regex_t;
357
358 /* Type for byte offsets within the string. POSIX mandates this. */
359 typedef int regoff_t;
360
361
362 /* This is the structure we store register match data in. See
363 regex.texinfo for a full description of what registers match. */
364 struct re_registers
365 {
366 unsigned num_regs;
367 regoff_t *start;
368 regoff_t *end;
369 };
370
371
372 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
373 `re_match_2' returns information about at least this many registers
374 the first time a `regs' structure is passed. */
375 #ifndef RE_NREGS
376 #define RE_NREGS 30
377 #endif
378
379
380 /* POSIX specification for registers. Aside from the different names than
381 `re_registers', POSIX uses an array of structures, instead of a
382 structure of arrays. */
383 typedef struct
384 {
385 regoff_t rm_so; /* Byte offset from string's start to substring's start. */
386 regoff_t rm_eo; /* Byte offset from string's start to substring's end. */
387 } regmatch_t;
388
389 /* Declarations for routines. */
390
391 /* To avoid duplicating every routine declaration -- once with a
392 prototype (if we are ANSI), and once without (if we aren't) -- we
393 use the following macro to declare argument types. This
394 unfortunately clutters up the declarations a bit, but I think it's
395 worth it. */
396
397 #ifdef __STDC__
398
399 #define _RE_ARGS(args) args
400
401 #else /* not __STDC__ */
402
403 #define _RE_ARGS(args) ()
404
405 #endif /* not __STDC__ */
406
407 /* Sets the current default syntax to SYNTAX, and return the old syntax.
408 You can also simply assign to the `re_syntax_options' variable. */
409 extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
410
411 /* Compile the regular expression PATTERN, with length LENGTH
412 and syntax given by the global `re_syntax_options', into the buffer
413 BUFFER. Return NULL if successful, and an error string if not. */
414 extern CONST char *re_compile_pattern
415 _RE_ARGS ((CONST char *pattern, int length,
416 struct re_pattern_buffer *buffer));
417
418
419 /* Compile a fastmap for the compiled pattern in BUFFER; used to
420 accelerate searches. Return 0 if successful and -2 if was an
421 internal error. */
422 extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
423
424
425 /* Search in the string STRING (with length LENGTH) for the pattern
426 compiled into BUFFER. Start searching at position START, for RANGE
427 characters. Return the starting position of the match, -1 for no
428 match, or -2 for an internal error. Also return register
429 information in REGS (if REGS and BUFFER->no_sub are nonzero). */
430 extern int re_search
431 _RE_ARGS ((struct re_pattern_buffer *buffer, CONST char *string,
432 int length, int start, int range, struct re_registers *regs));
433
434
435 /* Like `re_search', but search in the concatenation of STRING1 and
436 STRING2. Also, stop searching at index START + STOP. */
437 extern int re_search_2
438 _RE_ARGS ((struct re_pattern_buffer *buffer, CONST char *string1,
439 int length1, CONST char *string2, int length2,
440 int start, int range, struct re_registers *regs, int stop));
441
442
443 /* Like `re_search', but return how many characters in STRING the regexp
444 in BUFFER matched, starting at position START. */
445 extern int re_match
446 _RE_ARGS ((struct re_pattern_buffer *buffer, CONST char *string,
447 int length, int start, struct re_registers *regs));
448
449
450 /* Relates to `re_match' as `re_search_2' relates to `re_search'. */
451 extern int re_match_2
452 _RE_ARGS ((struct re_pattern_buffer *buffer, CONST char *string1,
453 int length1, CONST char *string2, int length2,
454 int start, struct re_registers *regs, int stop));
455
456
457 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
458 ENDS. Subsequent matches using BUFFER and REGS will use this memory
459 for recording register information. STARTS and ENDS must be
460 allocated with malloc, and must each be at least `NUM_REGS * sizeof
461 (regoff_t)' bytes long.
462
463 If NUM_REGS == 0, then subsequent matches should allocate their own
464 register data.
465
466 Unless this function is called, the first search or match using
467 PATTERN_BUFFER will allocate its own register data, without
468 freeing the old data. */
469 extern void re_set_registers
470 _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
471 unsigned num_regs, regoff_t *starts, regoff_t *ends));
472
473 #ifdef _REGEX_RE_COMP
474 /* 4.2 bsd compatibility. */
475 extern char *re_comp _RE_ARGS ((CONST char *));
476 extern int re_exec _RE_ARGS ((CONST char *));
477 #endif
478
479 /* POSIX compatibility. */
480 extern int regcomp _RE_ARGS ((regex_t *preg, CONST char *pattern, int cflags));
481 extern int regexec
482 _RE_ARGS ((CONST regex_t *preg, CONST char *string, size_t nmatch,
483 regmatch_t pmatch[], int eflags));
484 extern size_t regerror
485 _RE_ARGS ((int errcode, CONST regex_t *preg, char *errbuf,
486 size_t errbuf_size));
487 extern void regfree _RE_ARGS ((regex_t *preg));
488
489 #endif /* not __REGEXP_LIBRARY_H__ */
490
491 /*
492 Local variables:
493 make-backup-files: t
494 version-control: t
495 trim-versions-without-asking: nil
496 End:
497 */