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