xref: /openbsd-src/gnu/usr.bin/perl/regexp.h (revision ac9b4aacc1da35008afea06a5d23c2f2dea9b93e)
1 /*    regexp.h
2  *
3  *    Copyright (C) 1993, 1994, 1996, 1997, 1999, 2000, 2001, 2003,
4  *    2005, 2006, 2007, 2008 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  */
10 
11 /*
12  * Definitions etc. for regexp(3) routines.
13  *
14  * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
15  * not the System V one.
16  */
17 #ifndef PLUGGABLE_RE_EXTENSION
18 /* we don't want to include this stuff if we are inside of
19    an external regex engine based on the core one - like re 'debug'*/
20 
21 struct regnode {
22     U8	flags;
23     U8  type;
24     U16 next_off;
25 };
26 
27 typedef struct regnode regnode;
28 
29 struct reg_substr_data;
30 
31 struct reg_data;
32 
33 struct regexp_engine;
34 struct regexp;
35 
36 struct reg_substr_datum {
37     I32 min_offset;
38     I32 max_offset;
39     SV *substr;		/* non-utf8 variant */
40     SV *utf8_substr;	/* utf8 variant */
41     I32 end_shift;
42 };
43 struct reg_substr_data {
44     struct reg_substr_datum data[3];	/* Actual array */
45 };
46 
47 #ifdef PERL_OLD_COPY_ON_WRITE
48 #define SV_SAVED_COPY   SV *saved_copy; /* If non-NULL, SV which is COW from original */
49 #else
50 #define SV_SAVED_COPY
51 #endif
52 
53 typedef struct regexp_paren_pair {
54     I32 start;
55     I32 end;
56 } regexp_paren_pair;
57 
58 /*
59   The regexp/REGEXP struct, see L<perlreapi> for further documentation
60   on the individual fields. The struct is ordered so that the most
61   commonly used fields are placed at the start.
62 
63   Any patch that adds items to this struct will need to include
64   changes to F<sv.c> (C<Perl_re_dup()>) and F<regcomp.c>
65   (C<pregfree()>). This involves freeing or cloning items in the
66   regexp's data array based on the data item's type.
67 */
68 
69 #define _REGEXP_COMMON							\
70         /* what engine created this regexp? */				\
71 	const struct regexp_engine* engine; 				\
72 	REGEXP *mother_re; /* what re is this a lightweight copy of? */	\
73 	/* Information about the match that the perl core uses to */	\
74 	/* manage things */						\
75 	U32 extflags;	/* Flags used both externally and internally */	\
76 	I32 minlen;	/* mininum possible length of string to match */\
77 	I32 minlenret;	/* mininum possible length of $& */		\
78 	U32 gofs;	/* chars left of pos that we search from */	\
79 	/* substring data about strings that must appear in the */	\
80 	/* final match, used for optimisations */			\
81 	struct reg_substr_data *substrs;				\
82 	U32 nparens;	/* number of capture buffers */			\
83 	/* private engine specific data */				\
84 	U32 intflags;	/* Engine Specific Internal flags */		\
85 	void *pprivate;	/* Data private to the regex engine which */	\
86 			/* created this object. */			\
87 	/* Data about the last/current match. These are modified */	\
88 	/* during matching */						\
89 	U32 lastparen;			/* last open paren matched */	\
90 	U32 lastcloseparen;		/* last close paren matched */	\
91 	regexp_paren_pair *swap;	/* Unused: 5.10.1 and later */	\
92 	/* Array of offsets for (@-) and (@+) */			\
93 	regexp_paren_pair *offs;					\
94 	/* saved or original string so \digit works forever. */		\
95 	char *subbeg;							\
96 	SV_SAVED_COPY	/* If non-NULL, SV which is COW from original */\
97 	I32 sublen;	/* Length of string pointed by subbeg */	\
98 	/* Information about the match that isn't often used */		\
99 	/* offset from wrapped to the start of precomp */		\
100 	PERL_BITFIELD32 pre_prefix:4;					\
101 	/* number of eval groups in the pattern - for security checks */\
102 	PERL_BITFIELD32 seen_evals:28
103 
104 typedef struct regexp {
105 	_XPV_HEAD;
106 	_XPVMG_HEAD;
107 	_REGEXP_COMMON;
108 } regexp;
109 
110 /*        HV *paren_names;	 Optional hash of paren names
111 	  now stored in the IV union */
112 
113 #define RXp_PAREN_NAMES(rx)	((rx)->xiv_u.xivu_hv)
114 
115 /* used for high speed searches */
116 typedef struct re_scream_pos_data_s
117 {
118     char **scream_olds;		/* match pos */
119     I32 *scream_pos;		/* Internal iterator of scream. */
120 } re_scream_pos_data;
121 
122 /* regexp_engine structure. This is the dispatch table for regexes.
123  * Any regex engine implementation must be able to build one of these.
124  */
125 typedef struct regexp_engine {
126     REGEXP* (*comp) (pTHX_ SV * const pattern, U32 flags);
127     I32     (*exec) (pTHX_ REGEXP * const rx, char* stringarg, char* strend,
128                      char* strbeg, I32 minend, SV* screamer,
129                      void* data, U32 flags);
130     char*   (*intuit) (pTHX_ REGEXP * const rx, SV *sv, char *strpos,
131                        char *strend, const U32 flags,
132                        re_scream_pos_data *data);
133     SV*     (*checkstr) (pTHX_ REGEXP * const rx);
134     void    (*free) (pTHX_ REGEXP * const rx);
135     void    (*numbered_buff_FETCH) (pTHX_ REGEXP * const rx, const I32 paren,
136                                     SV * const sv);
137     void    (*numbered_buff_STORE) (pTHX_ REGEXP * const rx, const I32 paren,
138                                    SV const * const value);
139     I32     (*numbered_buff_LENGTH) (pTHX_ REGEXP * const rx, const SV * const sv,
140                                     const I32 paren);
141     SV*     (*named_buff) (pTHX_ REGEXP * const rx, SV * const key,
142                            SV * const value, const U32 flags);
143     SV*     (*named_buff_iter) (pTHX_ REGEXP * const rx, const SV * const lastkey,
144                                 const U32 flags);
145     SV*     (*qr_package)(pTHX_ REGEXP * const rx);
146 #ifdef USE_ITHREADS
147     void*   (*dupe) (pTHX_ REGEXP * const rx, CLONE_PARAMS *param);
148 #endif
149 } regexp_engine;
150 
151 /*
152   These are passed to the numbered capture variable callbacks as the
153   paren name. >= 1 is reserved for actual numbered captures, i.e. $1,
154   $2 etc.
155 */
156 #define RX_BUFF_IDX_PREMATCH  -2 /* $` / ${^PREMATCH}  */
157 #define RX_BUFF_IDX_POSTMATCH -1 /* $' / ${^POSTMATCH} */
158 #define RX_BUFF_IDX_FULLMATCH      0 /* $& / ${^MATCH}     */
159 
160 /*
161   Flags that are passed to the named_buff and named_buff_iter
162   callbacks above. Those routines are called from universal.c via the
163   Tie::Hash::NamedCapture interface for %+ and %- and the re::
164   functions in the same file.
165 */
166 
167 /* The Tie::Hash::NamedCapture operation this is part of, if any */
168 #define RXapif_FETCH     0x0001
169 #define RXapif_STORE     0x0002
170 #define RXapif_DELETE    0x0004
171 #define RXapif_CLEAR     0x0008
172 #define RXapif_EXISTS    0x0010
173 #define RXapif_SCALAR    0x0020
174 #define RXapif_FIRSTKEY  0x0040
175 #define RXapif_NEXTKEY   0x0080
176 
177 /* Whether %+ or %- is being operated on */
178 #define RXapif_ONE       0x0100 /* %+ */
179 #define RXapif_ALL       0x0200 /* %- */
180 
181 /* Whether this is being called from a re:: function */
182 #define RXapif_REGNAME         0x0400
183 #define RXapif_REGNAMES        0x0800
184 #define RXapif_REGNAMES_COUNT  0x1000
185 
186 /*
187 =head1 REGEXP Functions
188 
189 =for apidoc Am|REGEXP *|SvRX|SV *sv
190 
191 Convenience macro to get the REGEXP from a SV. This is approximately
192 equivalent to the following snippet:
193 
194     if (SvMAGICAL(sv))
195         mg_get(sv);
196     if (SvROK(sv) &&
197         (tmpsv = (SV*)SvRV(sv)) &&
198         SvTYPE(tmpsv) == SVt_PVMG &&
199         (tmpmg = mg_find(tmpsv, PERL_MAGIC_qr)))
200     {
201         return (REGEXP *)tmpmg->mg_obj;
202     }
203 
204 NULL will be returned if a REGEXP* is not found.
205 
206 =for apidoc Am|bool|SvRXOK|SV* sv
207 
208 Returns a boolean indicating whether the SV contains qr magic
209 (PERL_MAGIC_qr).
210 
211 If you want to do something with the REGEXP* later use SvRX instead
212 and check for NULL.
213 
214 =cut
215 */
216 
217 #define SvRX(sv)   (Perl_get_re_arg(aTHX_ sv))
218 #define SvRXOK(sv) (Perl_get_re_arg(aTHX_ sv) ? TRUE : FALSE)
219 
220 
221 /* Flags stored in regexp->extflags
222  * These are used by code external to the regexp engine
223  *
224  * Note that flags starting with RXf_PMf_ have exact equivalents
225  * stored in op_pmflags and which are defined in op.h, they are defined
226  * numerically here only for clarity.
227  *
228  * NOTE: if you modify any RXf flags you should run regen.pl or regcomp.pl
229  * so that regnodes.h is updated with the changes.
230  *
231  */
232 
233 /* 0x3F of extflags is used by (RXf_)PMf_COMPILETIME
234  * If you change these you need to change the equivalent flags in op.h, and
235  * vice versa.  */
236 #define RXf_PMf_MULTILINE	0x00000001 /* /m         */
237 #define RXf_PMf_SINGLELINE	0x00000002 /* /s         */
238 #define RXf_PMf_FOLD    	0x00000004 /* /i         */
239 #define RXf_PMf_EXTENDED	0x00000008 /* /x         */
240 #define RXf_PMf_KEEPCOPY	0x00000010 /* /p         */
241 #define RXf_PMf_LOCALE  	0x00000020 /* use locale */
242 /* these flags are transfered from the PMOP->op_pmflags member during compilation */
243 #define RXf_PMf_STD_PMMOD_SHIFT	0
244 #define RXf_PMf_STD_PMMOD	(RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_FOLD|RXf_PMf_EXTENDED)
245 #define RXf_PMf_COMPILETIME	(RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_LOCALE|RXf_PMf_FOLD|RXf_PMf_EXTENDED|RXf_PMf_KEEPCOPY)
246 
247 #define CASE_STD_PMMOD_FLAGS_PARSE_SET(pmfl)                        \
248     case IGNORE_PAT_MOD:    *(pmfl) |= RXf_PMf_FOLD;       break;   \
249     case MULTILINE_PAT_MOD: *(pmfl) |= RXf_PMf_MULTILINE;  break;   \
250     case SINGLE_PAT_MOD:    *(pmfl) |= RXf_PMf_SINGLELINE; break;   \
251     case XTENDED_PAT_MOD:   *(pmfl) |= RXf_PMf_EXTENDED;   break
252 
253 /* chars and strings used as regex pattern modifiers
254  * Singlular is a 'c'har, plural is a "string"
255  *
256  * NOTE, KEEPCOPY was originally 'k', but was changed to 'p' for preserve
257  * for compatibility reasons with Regexp::Common which highjacked (?k:...)
258  * for its own uses. So 'k' is out as well.
259  */
260 #define EXEC_PAT_MOD         'e'
261 #define KEEPCOPY_PAT_MOD     'p'
262 #define ONCE_PAT_MOD         'o'
263 #define GLOBAL_PAT_MOD       'g'
264 #define CONTINUE_PAT_MOD     'c'
265 #define MULTILINE_PAT_MOD    'm'
266 #define SINGLE_PAT_MOD       's'
267 #define IGNORE_PAT_MOD       'i'
268 #define XTENDED_PAT_MOD      'x'
269 
270 #define ONCE_PAT_MODS        "o"
271 #define KEEPCOPY_PAT_MODS    "p"
272 #define EXEC_PAT_MODS        "e"
273 #define LOOP_PAT_MODS        "gc"
274 
275 #define STD_PAT_MODS        "msix"
276 
277 #define INT_PAT_MODS    STD_PAT_MODS    KEEPCOPY_PAT_MODS
278 
279 #define EXT_PAT_MODS    ONCE_PAT_MODS   KEEPCOPY_PAT_MODS
280 #define QR_PAT_MODS     STD_PAT_MODS    EXT_PAT_MODS
281 #define M_PAT_MODS      QR_PAT_MODS     LOOP_PAT_MODS
282 #define S_PAT_MODS      M_PAT_MODS      EXEC_PAT_MODS
283 
284 /*
285  * NOTE: if you modify any RXf flags you should run regen.pl or regcomp.pl
286  * so that regnodes.h is updated with the changes.
287  *
288  */
289 
290 /* Anchor and GPOS related stuff */
291 #define RXf_ANCH_BOL    	0x00000100
292 #define RXf_ANCH_MBOL   	0x00000200
293 #define RXf_ANCH_SBOL   	0x00000400
294 #define RXf_ANCH_GPOS   	0x00000800
295 #define RXf_GPOS_SEEN   	0x00001000
296 #define RXf_GPOS_FLOAT  	0x00002000
297 /* two bits here */
298 #define RXf_ANCH        	(RXf_ANCH_BOL|RXf_ANCH_MBOL|RXf_ANCH_GPOS|RXf_ANCH_SBOL)
299 #define RXf_GPOS_CHECK          (RXf_GPOS_SEEN|RXf_ANCH_GPOS)
300 #define RXf_ANCH_SINGLE         (RXf_ANCH_SBOL|RXf_ANCH_GPOS)
301 
302 /* What we have seen */
303 #define RXf_LOOKBEHIND_SEEN	0x00004000
304 #define RXf_EVAL_SEEN   	0x00008000
305 #define RXf_CANY_SEEN   	0x00010000
306 
307 /* Special */
308 #define RXf_NOSCAN      	0x00020000
309 #define RXf_CHECK_ALL   	0x00040000
310 
311 /* UTF8 related */
312 #define RXf_MATCH_UTF8  	0x00100000
313 
314 /* Intuit related */
315 #define RXf_USE_INTUIT_NOML	0x00200000
316 #define RXf_USE_INTUIT_ML	0x00400000
317 #define RXf_INTUIT_TAIL 	0x00800000
318 
319 /*
320   Set in Perl_pmruntime if op_flags & OPf_SPECIAL, i.e. split. Will
321   be used by regex engines to check whether they should set
322   RXf_SKIPWHITE
323 */
324 #define RXf_SPLIT		0x01000000
325 
326 #define RXf_USE_INTUIT		(RXf_USE_INTUIT_NOML|RXf_USE_INTUIT_ML)
327 
328 /* Copy and tainted info */
329 #define RXf_COPY_DONE   	0x02000000
330 #define RXf_TAINTED_SEEN	0x04000000
331 #define RXf_TAINTED		0x08000000 /* this pattern is tainted */
332 
333 /* Flags indicating special patterns */
334 #define RXf_START_ONLY		0x10000000 /* Pattern is /^/ */
335 #define RXf_SKIPWHITE		0x20000000 /* Pattern is for a split / / */
336 #define RXf_WHITE		0x40000000 /* Pattern is /\s+/ */
337 #define RXf_NULL		0x80000000 /* Pattern is // */
338 
339 /*
340  * NOTE: if you modify any RXf flags you should run regen.pl or regcomp.pl
341  * so that regnodes.h is updated with the changes.
342  *
343  */
344 
345 #define RX_HAS_CUTGROUP(prog) ((prog)->intflags & PREGf_CUTGROUP_SEEN)
346 #define RXp_MATCH_TAINTED(prog)	(RXp_EXTFLAGS(prog) & RXf_TAINTED_SEEN)
347 #define RX_MATCH_TAINTED(prog)	(RX_EXTFLAGS(prog) & RXf_TAINTED_SEEN)
348 #define RX_MATCH_TAINTED_on(prog) (RX_EXTFLAGS(prog) |= RXf_TAINTED_SEEN)
349 #define RX_MATCH_TAINTED_off(prog) (RX_EXTFLAGS(prog) &= ~RXf_TAINTED_SEEN)
350 #define RX_MATCH_TAINTED_set(prog, t) ((t) \
351 				       ? RX_MATCH_TAINTED_on(prog) \
352 				       : RX_MATCH_TAINTED_off(prog))
353 
354 #define RXp_MATCH_COPIED(prog)		(RXp_EXTFLAGS(prog) & RXf_COPY_DONE)
355 #define RX_MATCH_COPIED(prog)		(RX_EXTFLAGS(prog) & RXf_COPY_DONE)
356 #define RXp_MATCH_COPIED_on(prog)	(RXp_EXTFLAGS(prog) |= RXf_COPY_DONE)
357 #define RX_MATCH_COPIED_on(prog)	(RX_EXTFLAGS(prog) |= RXf_COPY_DONE)
358 #define RXp_MATCH_COPIED_off(prog)	(RXp_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
359 #define RX_MATCH_COPIED_off(prog)	(RX_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
360 #define RX_MATCH_COPIED_set(prog,t)	((t) \
361 					 ? RX_MATCH_COPIED_on(prog) \
362 					 : RX_MATCH_COPIED_off(prog))
363 
364 #define RXp_EXTFLAGS(rx)	((rx)->extflags)
365 
366 /* For source compatibility. We used to store these explicitly.  */
367 #define RX_PRECOMP(prog)	(RX_WRAPPED(prog) + ((struct regexp *)SvANY(prog))->pre_prefix)
368 #define RX_PRECOMP_const(prog)	(RX_WRAPPED_const(prog) + ((struct regexp *)SvANY(prog))->pre_prefix)
369 /* FIXME? Are we hardcoding too much here and constraining plugin extension
370    writers? Specifically, the value 1 assumes that the wrapped version always
371    has exactly one character at the end, a ')'. Will that always be true?  */
372 #define RX_PRELEN(prog)		(RX_WRAPLEN(prog) - ((struct regexp *)SvANY(prog))->pre_prefix - 1)
373 #define RX_WRAPPED(prog)	SvPVX(prog)
374 #define RX_WRAPPED_const(prog)	SvPVX_const(prog)
375 #define RX_WRAPLEN(prog)	SvCUR(prog)
376 #define RX_CHECK_SUBSTR(prog)	(((struct regexp *)SvANY(prog))->check_substr)
377 #define RX_REFCNT(prog)		SvREFCNT(prog)
378 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
379 #  define RX_EXTFLAGS(prog)						\
380     (*({								\
381 	const REGEXP *const _rx_extflags = (prog);			\
382 	assert(SvTYPE(_rx_extflags) == SVt_REGEXP);			\
383 	&RXp_EXTFLAGS(SvANY(_rx_extflags));				\
384     }))
385 #  define RX_ENGINE(prog)						\
386     (*({								\
387 	const REGEXP *const _rx_engine = (prog);			\
388 	assert(SvTYPE(_rx_engine) == SVt_REGEXP);			\
389 	&SvANY(_rx_engine)->engine;					\
390     }))
391 #  define RX_SUBBEG(prog)						\
392     (*({								\
393 	const REGEXP *const _rx_subbeg = (prog);			\
394 	assert(SvTYPE(_rx_subbeg) == SVt_REGEXP);			\
395 	&SvANY(_rx_subbeg)->subbeg;					\
396     }))
397 #  define RX_OFFS(prog)							\
398     (*({								\
399 	const REGEXP *const _rx_offs = (prog);				\
400 	assert(SvTYPE(_rx_offs) == SVt_REGEXP);				\
401 	&SvANY(_rx_offs)->offs;						\
402     }))
403 #  define RX_NPARENS(prog)						\
404     (*({								\
405 	const REGEXP *const _rx_nparens = (prog);			\
406 	assert(SvTYPE(_rx_nparens) == SVt_REGEXP);			\
407 	&SvANY(_rx_nparens)->nparens;					\
408     }))
409 #else
410 #  define RX_EXTFLAGS(prog)	RXp_EXTFLAGS((struct regexp *)SvANY(prog))
411 #  define RX_ENGINE(prog)	(((struct regexp *)SvANY(prog))->engine)
412 #  define RX_SUBBEG(prog)	(((struct regexp *)SvANY(prog))->subbeg)
413 #  define RX_OFFS(prog)		(((struct regexp *)SvANY(prog))->offs)
414 #  define RX_NPARENS(prog)	(((struct regexp *)SvANY(prog))->nparens)
415 #endif
416 #define RX_SUBLEN(prog)		(((struct regexp *)SvANY(prog))->sublen)
417 #define RX_MINLEN(prog)		(((struct regexp *)SvANY(prog))->minlen)
418 #define RX_MINLENRET(prog)	(((struct regexp *)SvANY(prog))->minlenret)
419 #define RX_GOFS(prog)		(((struct regexp *)SvANY(prog))->gofs)
420 #define RX_LASTPAREN(prog)	(((struct regexp *)SvANY(prog))->lastparen)
421 #define RX_LASTCLOSEPAREN(prog)	(((struct regexp *)SvANY(prog))->lastcloseparen)
422 #define RX_SEEN_EVALS(prog)	(((struct regexp *)SvANY(prog))->seen_evals)
423 #define RX_SAVED_COPY(prog)	(((struct regexp *)SvANY(prog))->saved_copy)
424 
425 #endif /* PLUGGABLE_RE_EXTENSION */
426 
427 /* Stuff that needs to be included in the plugable extension goes below here */
428 
429 #ifdef PERL_OLD_COPY_ON_WRITE
430 #define RX_MATCH_COPY_FREE(rx) \
431 	STMT_START {if (RX_SAVED_COPY(rx)) { \
432 	    SV_CHECK_THINKFIRST_COW_DROP(RX_SAVED_COPY(rx)); \
433 	} \
434 	if (RX_MATCH_COPIED(rx)) { \
435 	    Safefree(RX_SUBBEG(rx)); \
436 	    RX_MATCH_COPIED_off(rx); \
437 	}} STMT_END
438 #else
439 #define RX_MATCH_COPY_FREE(rx) \
440 	STMT_START {if (RX_MATCH_COPIED(rx)) { \
441 	    Safefree(RX_SUBBEG(rx)); \
442 	    RX_MATCH_COPIED_off(rx); \
443 	}} STMT_END
444 #endif
445 
446 #define RXp_MATCH_UTF8(prog)		(RXp_EXTFLAGS(prog) & RXf_MATCH_UTF8)
447 #define RX_MATCH_UTF8(prog)		(RX_EXTFLAGS(prog) & RXf_MATCH_UTF8)
448 #define RX_MATCH_UTF8_on(prog)		(RX_EXTFLAGS(prog) |= RXf_MATCH_UTF8)
449 #define RX_MATCH_UTF8_off(prog)		(RX_EXTFLAGS(prog) &= ~RXf_MATCH_UTF8)
450 #define RX_MATCH_UTF8_set(prog, t)	((t) \
451 			? (RX_MATCH_UTF8_on(prog), (PL_reg_match_utf8 = 1)) \
452 			: (RX_MATCH_UTF8_off(prog), (PL_reg_match_utf8 = 0)))
453 
454 /* Whether the pattern stored at RX_WRAPPED is in UTF-8  */
455 #define RX_UTF8(prog)			SvUTF8(prog)
456 
457 #define REXEC_COPY_STR	0x01		/* Need to copy the string. */
458 #define REXEC_CHECKED	0x02		/* check_substr already checked. */
459 #define REXEC_SCREAM	0x04		/* use scream table. */
460 #define REXEC_IGNOREPOS	0x08		/* \G matches at start. */
461 #define REXEC_NOT_FIRST	0x10		/* This is another iteration of //g. */
462 
463 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
464 #  define ReREFCNT_inc(re)						\
465     ({									\
466 	/* This is here to generate a casting warning if incorrect.  */	\
467 	REGEXP *const _rerefcnt_inc = (re);				\
468 	assert(SvTYPE(_rerefcnt_inc) == SVt_REGEXP);			\
469 	SvREFCNT_inc(_rerefcnt_inc);					\
470 	_rerefcnt_inc;							\
471     })
472 #  define ReREFCNT_dec(re)						\
473     ({									\
474 	/* This is here to generate a casting warning if incorrect.  */	\
475 	REGEXP *const _rerefcnt_dec = (re);				\
476 	SvREFCNT_dec(_rerefcnt_dec);					\
477     })
478 #else
479 #  define ReREFCNT_dec(re)	SvREFCNT_dec(re)
480 #  define ReREFCNT_inc(re)	((REGEXP *) SvREFCNT_inc(re))
481 #endif
482 
483 /* FIXME for plugins. */
484 
485 #define FBMcf_TAIL_DOLLAR	1
486 #define FBMcf_TAIL_DOLLARM	2
487 #define FBMcf_TAIL_Z		4
488 #define FBMcf_TAIL_z		8
489 #define FBMcf_TAIL		(FBMcf_TAIL_DOLLAR|FBMcf_TAIL_DOLLARM|FBMcf_TAIL_Z|FBMcf_TAIL_z)
490 
491 #define FBMrf_MULTILINE	1
492 
493 /* an accepting state/position*/
494 struct _reg_trie_accepted {
495     U8   *endpos;
496     U16  wordnum;
497 };
498 typedef struct _reg_trie_accepted reg_trie_accepted;
499 
500 /* some basic information about the current match that is created by
501  * Perl_regexec_flags and then passed to regtry(), regmatch() etc */
502 
503 typedef struct {
504     REGEXP *prog;
505     char *bol;
506     char *till;
507     SV *sv;
508     char *ganch;
509     char *cutpoint;
510 } regmatch_info;
511 
512 
513 /* structures for holding and saving the state maintained by regmatch() */
514 
515 #ifndef MAX_RECURSE_EVAL_NOCHANGE_DEPTH
516 #define MAX_RECURSE_EVAL_NOCHANGE_DEPTH 1000
517 #endif
518 
519 typedef I32 CHECKPOINT;
520 
521 typedef struct regmatch_state {
522     int resume_state;		/* where to jump to on return */
523     char *locinput;		/* where to backtrack in string on failure */
524 
525     union {
526 
527 	/* this is a fake union member that matches the first element
528 	 * of each member that needs to store positive backtrack
529 	 * information */
530 	struct {
531 	    struct regmatch_state *prev_yes_state;
532 	} yes;
533 
534         /* branchlike members */
535         /* this is a fake union member that matches the first elements
536          * of each member that needs to behave like a branch */
537         struct {
538 	    /* this first element must match u.yes */
539 	    struct regmatch_state *prev_yes_state;
540 	    U32 lastparen;
541 	    CHECKPOINT cp;
542 
543         } branchlike;
544 
545 	struct {
546 	    /* the first elements must match u.branchlike */
547 	    struct regmatch_state *prev_yes_state;
548 	    U32 lastparen;
549 	    CHECKPOINT cp;
550 
551 	    regnode *next_branch; /* next branch node */
552 	} branch;
553 
554 	struct {
555 	    /* the first elements must match u.branchlike */
556 	    struct regmatch_state *prev_yes_state;
557 	    U32 lastparen;
558 	    CHECKPOINT cp;
559 
560 	    reg_trie_accepted *accept_buff; /* accepting states we have seen */
561 	    U32		accepted; /* how many accepting states we have seen */
562 	    U16         *jump;  /* positive offsets from me */
563 	    regnode	*B;	/* node following the trie */
564 	    regnode	*me;	/* Which node am I - needed for jump tries*/
565 	} trie;
566 
567         /* special types - these members are used to store state for special
568            regops like eval, if/then, lookaround and the markpoint state */
569 	struct {
570 	    /* this first element must match u.yes */
571 	    struct regmatch_state *prev_yes_state;
572 	    struct regmatch_state *prev_eval;
573 	    struct regmatch_state *prev_curlyx;
574 	    REGEXP	*prev_rex;
575 	    U32		toggle_reg_flags; /* what bits in PL_reg_flags to
576 					    flip when transitioning between
577 					    inner and outer rexen */
578 	    CHECKPOINT	cp;	/* remember current savestack indexes */
579 	    CHECKPOINT	lastcp;
580 	    U32        close_paren; /* which close bracket is our end */
581 	    regnode	*B;	/* the node following us  */
582 	} eval;
583 
584 	struct {
585 	    /* this first element must match u.yes */
586 	    struct regmatch_state *prev_yes_state;
587 	    I32 wanted;
588 	    I32 logical;	/* saved copy of 'logical' var */
589 	    regnode  *me; /* the IFMATCH/SUSPEND/UNLESSM node  */
590 	} ifmatch; /* and SUSPEND/UNLESSM */
591 
592 	struct {
593 	    /* this first element must match u.yes */
594 	    struct regmatch_state *prev_yes_state;
595 	    struct regmatch_state *prev_mark;
596 	    SV* mark_name;
597 	    char *mark_loc;
598 	} mark;
599 
600 	struct {
601 	    int val;
602 	} keeper;
603 
604         /* quantifiers - these members are used for storing state for
605            for the regops used to implement quantifiers */
606 	struct {
607 	    /* this first element must match u.yes */
608 	    struct regmatch_state *prev_yes_state;
609 	    struct regmatch_state *prev_curlyx; /* previous cur_curlyx */
610 	    regnode	*A, *B;	/* the nodes corresponding to /A*B/  */
611 	    CHECKPOINT	cp;	/* remember current savestack index */
612 	    bool	minmod;
613 	    int		parenfloor;/* how far back to strip paren data */
614 	    int		min;	/* the minimal number of A's to match */
615 	    int		max;	/* the maximal number of A's to match */
616 
617 	    /* these two are modified by WHILEM */
618 	    int		count;	/* how many instances of A we've matched */
619 	    char	*lastloc;/* where previous A matched (0-len detect) */
620 	} curlyx;
621 
622 	struct {
623 	    /* this first element must match u.yes */
624 	    struct regmatch_state *prev_yes_state;
625 	    struct regmatch_state *save_curlyx;
626 	    CHECKPOINT	cp;	/* remember current savestack indexes */
627 	    CHECKPOINT	lastcp;
628 	    char	*save_lastloc;	/* previous curlyx.lastloc */
629 	    I32		cache_offset;
630 	    I32		cache_mask;
631 	} whilem;
632 
633 	struct {
634 	    /* this first element must match u.yes */
635 	    struct regmatch_state *prev_yes_state;
636 	    I32 c1, c2;		/* case fold search */
637 	    CHECKPOINT cp;
638 	    I32 alen;		/* length of first-matched A string */
639 	    I32 count;
640 	    bool minmod;
641 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
642 	    regnode *me;	/* the curlym node */
643 	} curlym;
644 
645 	struct {
646 	    U32 paren;
647 	    CHECKPOINT cp;
648 	    I32 c1, c2;		/* case fold search */
649 	    char *maxpos;	/* highest possible point in string to match */
650 	    char *oldloc;	/* the previous locinput */
651 	    int count;
652 	    int min, max;	/* {m,n} */
653 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
654 	} curly; /* and CURLYN/PLUS/STAR */
655 
656     } u;
657 } regmatch_state;
658 
659 /* how many regmatch_state structs to allocate as a single slab.
660  * We do it in 4K blocks for efficiency. The "3" is 2 for the next/prev
661  * pointers, plus 1 for any mythical malloc overhead. */
662 
663 #define PERL_REGMATCH_SLAB_SLOTS \
664     ((4096 - 3 * sizeof (void*)) / sizeof(regmatch_state))
665 
666 typedef struct regmatch_slab {
667     regmatch_state states[PERL_REGMATCH_SLAB_SLOTS];
668     struct regmatch_slab *prev, *next;
669 } regmatch_slab;
670 
671 #define PL_reg_flags		PL_reg_state.re_state_reg_flags
672 #define PL_bostr		PL_reg_state.re_state_bostr
673 #define PL_reginput		PL_reg_state.re_state_reginput
674 #define PL_regeol		PL_reg_state.re_state_regeol
675 #define PL_regoffs		PL_reg_state.re_state_regoffs
676 #define PL_reglastparen		PL_reg_state.re_state_reglastparen
677 #define PL_reglastcloseparen	PL_reg_state.re_state_reglastcloseparen
678 #define PL_reg_start_tmp	PL_reg_state.re_state_reg_start_tmp
679 #define PL_reg_start_tmpl	PL_reg_state.re_state_reg_start_tmpl
680 #define PL_reg_eval_set		PL_reg_state.re_state_reg_eval_set
681 #define PL_reg_match_utf8	PL_reg_state.re_state_reg_match_utf8
682 #define PL_reg_magic		PL_reg_state.re_state_reg_magic
683 #define PL_reg_oldpos		PL_reg_state.re_state_reg_oldpos
684 #define PL_reg_oldcurpm		PL_reg_state.re_state_reg_oldcurpm
685 #define PL_reg_curpm		PL_reg_state.re_state_reg_curpm
686 #define PL_reg_oldsaved		PL_reg_state.re_state_reg_oldsaved
687 #define PL_reg_oldsavedlen	PL_reg_state.re_state_reg_oldsavedlen
688 #define PL_reg_maxiter		PL_reg_state.re_state_reg_maxiter
689 #define PL_reg_leftiter		PL_reg_state.re_state_reg_leftiter
690 #define PL_reg_poscache		PL_reg_state.re_state_reg_poscache
691 #define PL_reg_poscache_size	PL_reg_state.re_state_reg_poscache_size
692 #define PL_regsize		PL_reg_state.re_state_regsize
693 #define PL_reg_starttry		PL_reg_state.re_state_reg_starttry
694 #define PL_nrs			PL_reg_state.re_state_nrs
695 
696 struct re_save_state {
697     U32 re_state_reg_flags;		/* from regexec.c */
698     U32 re_state_reg_start_tmpl;	/* from regexec.c */
699     I32 re_state_reg_eval_set;		/* from regexec.c */
700     bool re_state_reg_match_utf8;	/* from regexec.c */
701     char *re_state_bostr;
702     char *re_state_reginput;		/* String-input pointer. */
703     char *re_state_regeol;		/* End of input, for $ check. */
704     regexp_paren_pair *re_state_regoffs;  /* Pointer to start/end pairs */
705     U32 *re_state_reglastparen;		/* Similarly for lastparen. */
706     U32 *re_state_reglastcloseparen;	/* Similarly for lastcloseparen. */
707     char **re_state_reg_start_tmp;	/* from regexec.c */
708     MAGIC *re_state_reg_magic;		/* from regexec.c */
709     PMOP *re_state_reg_oldcurpm;	/* from regexec.c */
710     PMOP *re_state_reg_curpm;		/* from regexec.c */
711     char *re_state_reg_oldsaved;	/* old saved substr during match */
712     STRLEN re_state_reg_oldsavedlen;	/* old length of saved substr during match */
713     STRLEN re_state_reg_poscache_size;	/* size of pos cache of WHILEM */
714     I32 re_state_reg_oldpos;		/* from regexec.c */
715     I32 re_state_reg_maxiter;		/* max wait until caching pos */
716     I32 re_state_reg_leftiter;		/* wait until caching pos */
717     U32 re_state_regsize;		/* from regexec.c */
718     char *re_state_reg_poscache;	/* cache of pos of WHILEM */
719     char *re_state_reg_starttry;	/* from regexec.c */
720 #ifdef PERL_OLD_COPY_ON_WRITE
721     SV *re_state_nrs;			/* was placeholder: unused since 5.8.0 (5.7.2 patch #12027 for bug ID 20010815.012). Used to save rx->saved_copy */
722 #endif
723 };
724 
725 #define SAVESTACK_ALLOC_FOR_RE_SAVE_STATE \
726 	(1 + ((sizeof(struct re_save_state) - 1) / sizeof(*PL_savestack)))
727 
728 /*
729  * Local variables:
730  * c-indentation-style: bsd
731  * c-basic-offset: 4
732  * indent-tabs-mode: t
733  * End:
734  *
735  * ex: set ts=8 sts=4 sw=4 noet:
736  */
737