xref: /openbsd-src/gnu/usr.bin/perl/regexp.h (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
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 #if defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_UTF8_C)
59 #define _invlist_union(a, b, output) _invlist_union_maybe_complement_2nd(a, b, FALSE, output)
60 #define _invlist_intersection(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, FALSE, output)
61 
62 /* Subtracting b from a leaves in a everything that was there that isn't in b,
63  * that is the intersection of a with b's complement */
64 #define _invlist_subtract(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, TRUE, output)
65 #endif
66 
67 /*
68   The regexp/REGEXP struct, see L<perlreapi> for further documentation
69   on the individual fields. The struct is ordered so that the most
70   commonly used fields are placed at the start.
71 
72   Any patch that adds items to this struct will need to include
73   changes to F<sv.c> (C<Perl_re_dup()>) and F<regcomp.c>
74   (C<pregfree()>). This involves freeing or cloning items in the
75   regexp's data array based on the data item's type.
76 */
77 
78 #define _REGEXP_COMMON							\
79         /* what engine created this regexp? */				\
80 	const struct regexp_engine* engine; 				\
81 	REGEXP *mother_re; /* what re is this a lightweight copy of? */	\
82 	HV *paren_names;   /* Optional hash of paren names */		\
83 	/* Information about the match that the perl core uses to */	\
84 	/* manage things */						\
85 	U32 extflags;	/* Flags used both externally and internally */	\
86 	I32 minlen;	/* mininum possible length of string to match */\
87 	I32 minlenret;	/* mininum possible length of $& */		\
88 	U32 gofs;	/* chars left of pos that we search from */	\
89 	/* substring data about strings that must appear in the */	\
90 	/* final match, used for optimisations */			\
91 	struct reg_substr_data *substrs;				\
92 	U32 nparens;	/* number of capture buffers */			\
93 	/* private engine specific data */				\
94 	U32 intflags;	/* Engine Specific Internal flags */		\
95 	void *pprivate;	/* Data private to the regex engine which */	\
96 			/* created this object. */			\
97 	/* Data about the last/current match. These are modified */	\
98 	/* during matching */						\
99 	U32 lastparen;			/* last open paren matched */	\
100 	U32 lastcloseparen;		/* last close paren matched */	\
101 	regexp_paren_pair *swap;	/* Unused: 5.10.1 and later */	\
102 	/* Array of offsets for (@-) and (@+) */			\
103 	regexp_paren_pair *offs;					\
104 	/* saved or original string so \digit works forever. */		\
105 	char *subbeg;							\
106 	SV_SAVED_COPY	/* If non-NULL, SV which is COW from original */\
107 	I32 sublen;	/* Length of string pointed by subbeg */	\
108 	/* Information about the match that isn't often used */		\
109 	/* offset from wrapped to the start of precomp */		\
110 	PERL_BITFIELD32 pre_prefix:4;					\
111 	/* number of eval groups in the pattern - for security checks */\
112 	PERL_BITFIELD32 seen_evals:28
113 
114 typedef struct regexp {
115 	_XPV_HEAD;
116 	_REGEXP_COMMON;
117 } regexp;
118 
119 #define RXp_PAREN_NAMES(rx)	((rx)->paren_names)
120 
121 /* used for high speed searches */
122 typedef struct re_scream_pos_data_s
123 {
124     char **scream_olds;		/* match pos */
125     I32 *scream_pos;		/* Internal iterator of scream. */
126 } re_scream_pos_data;
127 
128 /* regexp_engine structure. This is the dispatch table for regexes.
129  * Any regex engine implementation must be able to build one of these.
130  */
131 typedef struct regexp_engine {
132     REGEXP* (*comp) (pTHX_ SV * const pattern, U32 flags);
133     I32     (*exec) (pTHX_ REGEXP * const rx, char* stringarg, char* strend,
134                      char* strbeg, I32 minend, SV* screamer,
135                      void* data, U32 flags);
136     char*   (*intuit) (pTHX_ REGEXP * const rx, SV *sv, char *strpos,
137                        char *strend, const U32 flags,
138                        re_scream_pos_data *data);
139     SV*     (*checkstr) (pTHX_ REGEXP * const rx);
140     void    (*free) (pTHX_ REGEXP * const rx);
141     void    (*numbered_buff_FETCH) (pTHX_ REGEXP * const rx, const I32 paren,
142                                     SV * const sv);
143     void    (*numbered_buff_STORE) (pTHX_ REGEXP * const rx, const I32 paren,
144                                    SV const * const value);
145     I32     (*numbered_buff_LENGTH) (pTHX_ REGEXP * const rx, const SV * const sv,
146                                     const I32 paren);
147     SV*     (*named_buff) (pTHX_ REGEXP * const rx, SV * const key,
148                            SV * const value, const U32 flags);
149     SV*     (*named_buff_iter) (pTHX_ REGEXP * const rx, const SV * const lastkey,
150                                 const U32 flags);
151     SV*     (*qr_package)(pTHX_ REGEXP * const rx);
152 #ifdef USE_ITHREADS
153     void*   (*dupe) (pTHX_ REGEXP * const rx, CLONE_PARAMS *param);
154 #endif
155 } regexp_engine;
156 
157 /*
158   These are passed to the numbered capture variable callbacks as the
159   paren name. >= 1 is reserved for actual numbered captures, i.e. $1,
160   $2 etc.
161 */
162 #define RX_BUFF_IDX_PREMATCH  -2 /* $` / ${^PREMATCH}  */
163 #define RX_BUFF_IDX_POSTMATCH -1 /* $' / ${^POSTMATCH} */
164 #define RX_BUFF_IDX_FULLMATCH      0 /* $& / ${^MATCH}     */
165 
166 /*
167   Flags that are passed to the named_buff and named_buff_iter
168   callbacks above. Those routines are called from universal.c via the
169   Tie::Hash::NamedCapture interface for %+ and %- and the re::
170   functions in the same file.
171 */
172 
173 /* The Tie::Hash::NamedCapture operation this is part of, if any */
174 #define RXapif_FETCH     0x0001
175 #define RXapif_STORE     0x0002
176 #define RXapif_DELETE    0x0004
177 #define RXapif_CLEAR     0x0008
178 #define RXapif_EXISTS    0x0010
179 #define RXapif_SCALAR    0x0020
180 #define RXapif_FIRSTKEY  0x0040
181 #define RXapif_NEXTKEY   0x0080
182 
183 /* Whether %+ or %- is being operated on */
184 #define RXapif_ONE       0x0100 /* %+ */
185 #define RXapif_ALL       0x0200 /* %- */
186 
187 /* Whether this is being called from a re:: function */
188 #define RXapif_REGNAME         0x0400
189 #define RXapif_REGNAMES        0x0800
190 #define RXapif_REGNAMES_COUNT  0x1000
191 
192 /*
193 =head1 REGEXP Functions
194 
195 =for apidoc Am|REGEXP *|SvRX|SV *sv
196 
197 Convenience macro to get the REGEXP from a SV. This is approximately
198 equivalent to the following snippet:
199 
200     if (SvMAGICAL(sv))
201         mg_get(sv);
202     if (SvROK(sv))
203         sv = MUTABLE_SV(SvRV(sv));
204     if (SvTYPE(sv) == SVt_REGEXP)
205         return (REGEXP*) sv;
206 
207 NULL will be returned if a REGEXP* is not found.
208 
209 =for apidoc Am|bool|SvRXOK|SV* sv
210 
211 Returns a boolean indicating whether the SV (or the one it references)
212 is a REGEXP.
213 
214 If you want to do something with the REGEXP* later use SvRX instead
215 and check for NULL.
216 
217 =cut
218 */
219 
220 #define SvRX(sv)   (Perl_get_re_arg(aTHX_ sv))
221 #define SvRXOK(sv) (Perl_get_re_arg(aTHX_ sv) ? TRUE : FALSE)
222 
223 
224 /* Flags stored in regexp->extflags
225  * These are used by code external to the regexp engine
226  *
227  * Note that the flags whose names start with RXf_PMf_ are defined in
228  * op_reg_common.h, being copied from the parallel flags of op_pmflags
229  *
230  * NOTE: if you modify any RXf flags you should run regen.pl or
231  * regen/regcomp.pl so that regnodes.h is updated with the changes.
232  *
233  */
234 
235 #include "op_reg_common.h"
236 
237 #define RXf_PMf_STD_PMMOD	(RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_FOLD|RXf_PMf_EXTENDED)
238 
239 #define CASE_STD_PMMOD_FLAGS_PARSE_SET(pmfl)                        \
240     case IGNORE_PAT_MOD:    *(pmfl) |= RXf_PMf_FOLD;       break;   \
241     case MULTILINE_PAT_MOD: *(pmfl) |= RXf_PMf_MULTILINE;  break;   \
242     case SINGLE_PAT_MOD:    *(pmfl) |= RXf_PMf_SINGLELINE; break;   \
243     case XTENDED_PAT_MOD:   *(pmfl) |= RXf_PMf_EXTENDED;   break
244 
245 /* Note, includes charset ones, assumes 0 is the default for them */
246 #define STD_PMMOD_FLAGS_CLEAR(pmfl)                        \
247     *(pmfl) &= ~(RXf_PMf_FOLD|RXf_PMf_MULTILINE|RXf_PMf_SINGLELINE|RXf_PMf_EXTENDED|RXf_PMf_CHARSET)
248 
249 /* chars and strings used as regex pattern modifiers
250  * Singular is a 'c'har, plural is a "string"
251  *
252  * NOTE, KEEPCOPY was originally 'k', but was changed to 'p' for preserve
253  * for compatibility reasons with Regexp::Common which highjacked (?k:...)
254  * for its own uses. So 'k' is out as well.
255  */
256 #define DEFAULT_PAT_MOD      '^'    /* Short for all the default modifiers */
257 #define EXEC_PAT_MOD         'e'
258 #define KEEPCOPY_PAT_MOD     'p'
259 #define ONCE_PAT_MOD         'o'
260 #define GLOBAL_PAT_MOD       'g'
261 #define CONTINUE_PAT_MOD     'c'
262 #define MULTILINE_PAT_MOD    'm'
263 #define SINGLE_PAT_MOD       's'
264 #define IGNORE_PAT_MOD       'i'
265 #define XTENDED_PAT_MOD      'x'
266 #define NONDESTRUCT_PAT_MOD  'r'
267 #define LOCALE_PAT_MOD       'l'
268 #define UNICODE_PAT_MOD      'u'
269 #define DEPENDS_PAT_MOD      'd'
270 #define ASCII_RESTRICT_PAT_MOD 'a'
271 
272 #define ONCE_PAT_MODS        "o"
273 #define KEEPCOPY_PAT_MODS    "p"
274 #define EXEC_PAT_MODS        "e"
275 #define LOOP_PAT_MODS        "gc"
276 #define NONDESTRUCT_PAT_MODS "r"
277 #define LOCALE_PAT_MODS      "l"
278 #define UNICODE_PAT_MODS     "u"
279 #define DEPENDS_PAT_MODS     "d"
280 #define ASCII_RESTRICT_PAT_MODS "a"
281 #define ASCII_MORE_RESTRICT_PAT_MODS "aa"
282 
283 /* This string is expected by regcomp.c to be ordered so that the first
284  * character is the flag in bit RXf_PMf_STD_PMMOD_SHIFT of extflags; the next
285  * character is bit +1, etc. */
286 #define STD_PAT_MODS        "msix"
287 
288 #define CHARSET_PAT_MODS    ASCII_RESTRICT_PAT_MODS DEPENDS_PAT_MODS LOCALE_PAT_MODS UNICODE_PAT_MODS
289 
290 /* This string is expected by XS_re_regexp_pattern() in universal.c to be ordered
291  * so that the first character is the flag in bit RXf_PMf_STD_PMMOD_SHIFT of
292  * extflags; the next character is in bit +1, etc. */
293 #define INT_PAT_MODS    STD_PAT_MODS    KEEPCOPY_PAT_MODS
294 
295 #define EXT_PAT_MODS    ONCE_PAT_MODS   KEEPCOPY_PAT_MODS
296 #define QR_PAT_MODS     STD_PAT_MODS    EXT_PAT_MODS	   CHARSET_PAT_MODS
297 #define M_PAT_MODS      QR_PAT_MODS     LOOP_PAT_MODS
298 #define S_PAT_MODS      M_PAT_MODS      EXEC_PAT_MODS      NONDESTRUCT_PAT_MODS
299 
300 /*
301  * NOTE: if you modify any RXf flags you should run regen.pl or
302  * regen/regcomp.pl so that regnodes.h is updated with the changes.
303  *
304  */
305 
306 /* Leave some space, so future bit allocations can go either in the shared or
307  * unshared area without affecting binary compatibility */
308 #define RXf_BASE_SHIFT (_RXf_PMf_SHIFT_NEXT+1)
309 
310 /* Manually decorate this function with gcc-style attributes just to
311  * avoid having to restructure the header files and their called order,
312  * as proto.h would have to be included before this file, and isn't */
313 
314 PERL_STATIC_INLINE const char *
315 get_regex_charset_name(const U32 flags, STRLEN* const lenp)
316     __attribute__warn_unused_result__;
317 
318 #define MAX_CHARSET_NAME_LENGTH 2
319 
320 PERL_STATIC_INLINE const char *
321 get_regex_charset_name(const U32 flags, STRLEN* const lenp)
322 {
323     /* Returns a string that corresponds to the name of the regex character set
324      * given by 'flags', and *lenp is set the length of that string, which
325      * cannot exceed MAX_CHARSET_NAME_LENGTH characters */
326 
327     *lenp = 1;
328     switch (get_regex_charset(flags)) {
329         case REGEX_DEPENDS_CHARSET: return DEPENDS_PAT_MODS;
330         case REGEX_LOCALE_CHARSET:  return LOCALE_PAT_MODS;
331         case REGEX_UNICODE_CHARSET: return UNICODE_PAT_MODS;
332 	case REGEX_ASCII_RESTRICTED_CHARSET: return ASCII_RESTRICT_PAT_MODS;
333 	case REGEX_ASCII_MORE_RESTRICTED_CHARSET:
334 	    *lenp = 2;
335 	    return ASCII_MORE_RESTRICT_PAT_MODS;
336         default:
337 	    return "?";	    /* Unknown */
338     }
339 }
340 
341 /* Anchor and GPOS related stuff */
342 #define RXf_ANCH_BOL    	(1<<(RXf_BASE_SHIFT+0))
343 #define RXf_ANCH_MBOL   	(1<<(RXf_BASE_SHIFT+1))
344 #define RXf_ANCH_SBOL   	(1<<(RXf_BASE_SHIFT+2))
345 #define RXf_ANCH_GPOS   	(1<<(RXf_BASE_SHIFT+3))
346 #define RXf_GPOS_SEEN   	(1<<(RXf_BASE_SHIFT+4))
347 #define RXf_GPOS_FLOAT  	(1<<(RXf_BASE_SHIFT+5))
348 /* two bits here */
349 #define RXf_ANCH        	(RXf_ANCH_BOL|RXf_ANCH_MBOL|RXf_ANCH_GPOS|RXf_ANCH_SBOL)
350 #define RXf_GPOS_CHECK          (RXf_GPOS_SEEN|RXf_ANCH_GPOS)
351 #define RXf_ANCH_SINGLE         (RXf_ANCH_SBOL|RXf_ANCH_GPOS)
352 
353 /* What we have seen */
354 #define RXf_LOOKBEHIND_SEEN	(1<<(RXf_BASE_SHIFT+6))
355 #define RXf_EVAL_SEEN   	(1<<(RXf_BASE_SHIFT+7))
356 #define RXf_CANY_SEEN   	(1<<(RXf_BASE_SHIFT+8))
357 
358 /* Special */
359 #define RXf_NOSCAN      	(1<<(RXf_BASE_SHIFT+9))
360 #define RXf_CHECK_ALL   	(1<<(RXf_BASE_SHIFT+10))
361 
362 /* UTF8 related */
363 #define RXf_MATCH_UTF8  	(1<<(RXf_BASE_SHIFT+11))
364 
365 /* Intuit related */
366 #define RXf_USE_INTUIT_NOML	(1<<(RXf_BASE_SHIFT+12))
367 #define RXf_USE_INTUIT_ML	(1<<(RXf_BASE_SHIFT+13))
368 #define RXf_INTUIT_TAIL 	(1<<(RXf_BASE_SHIFT+14))
369 
370 /*
371   Set in Perl_pmruntime if op_flags & OPf_SPECIAL, i.e. split. Will
372   be used by regex engines to check whether they should set
373   RXf_SKIPWHITE
374 */
375 #define RXf_SPLIT		(1<<(RXf_BASE_SHIFT+15))
376 
377 #define RXf_USE_INTUIT		(RXf_USE_INTUIT_NOML|RXf_USE_INTUIT_ML)
378 
379 /* Copy and tainted info */
380 #define RXf_COPY_DONE   	(1<<(RXf_BASE_SHIFT+16))
381 
382 /* during execution: pattern temporarily tainted by executing locale ops;
383  * post-execution: $1 et al are tainted */
384 #define RXf_TAINTED_SEEN	(1<<(RXf_BASE_SHIFT+17))
385 /* this pattern was tainted during compilation */
386 #define RXf_TAINTED		(1<<(RXf_BASE_SHIFT+18))
387 
388 /* Flags indicating special patterns */
389 #define RXf_START_ONLY		(1<<(RXf_BASE_SHIFT+19)) /* Pattern is /^/ */
390 #define RXf_SKIPWHITE		(1<<(RXf_BASE_SHIFT+20)) /* Pattern is for a split / / */
391 #define RXf_WHITE		(1<<(RXf_BASE_SHIFT+21)) /* Pattern is /\s+/ */
392 #define RXf_NULL		(1U<<(RXf_BASE_SHIFT+22)) /* Pattern is // */
393 #if RXf_BASE_SHIFT+22 > 31
394 #   error Too many RXf_PMf bits used.  See regnodes.h for any spare in middle
395 #endif
396 
397 /*
398  * NOTE: if you modify any RXf flags you should run regen.pl or
399  * regen/regcomp.pl so that regnodes.h is updated with the changes.
400  *
401  */
402 
403 #define RX_HAS_CUTGROUP(prog) ((prog)->intflags & PREGf_CUTGROUP_SEEN)
404 #define RXp_MATCH_TAINTED(prog)	(RXp_EXTFLAGS(prog) & RXf_TAINTED_SEEN)
405 #define RX_MATCH_TAINTED(prog)	(RX_EXTFLAGS(prog) & RXf_TAINTED_SEEN)
406 #define RX_MATCH_TAINTED_on(prog) (RX_EXTFLAGS(prog) |= RXf_TAINTED_SEEN)
407 #define RX_MATCH_TAINTED_off(prog) (RX_EXTFLAGS(prog) &= ~RXf_TAINTED_SEEN)
408 #define RX_MATCH_TAINTED_set(prog, t) ((t) \
409 				       ? RX_MATCH_TAINTED_on(prog) \
410 				       : RX_MATCH_TAINTED_off(prog))
411 
412 #define RXp_MATCH_COPIED(prog)		(RXp_EXTFLAGS(prog) & RXf_COPY_DONE)
413 #define RX_MATCH_COPIED(prog)		(RX_EXTFLAGS(prog) & RXf_COPY_DONE)
414 #define RXp_MATCH_COPIED_on(prog)	(RXp_EXTFLAGS(prog) |= RXf_COPY_DONE)
415 #define RX_MATCH_COPIED_on(prog)	(RX_EXTFLAGS(prog) |= RXf_COPY_DONE)
416 #define RXp_MATCH_COPIED_off(prog)	(RXp_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
417 #define RX_MATCH_COPIED_off(prog)	(RX_EXTFLAGS(prog) &= ~RXf_COPY_DONE)
418 #define RX_MATCH_COPIED_set(prog,t)	((t) \
419 					 ? RX_MATCH_COPIED_on(prog) \
420 					 : RX_MATCH_COPIED_off(prog))
421 
422 #define RXp_EXTFLAGS(rx)	((rx)->extflags)
423 
424 /* For source compatibility. We used to store these explicitly.  */
425 #define RX_PRECOMP(prog)	(RX_WRAPPED(prog) + ((struct regexp *)SvANY(prog))->pre_prefix)
426 #define RX_PRECOMP_const(prog)	(RX_WRAPPED_const(prog) + ((struct regexp *)SvANY(prog))->pre_prefix)
427 /* FIXME? Are we hardcoding too much here and constraining plugin extension
428    writers? Specifically, the value 1 assumes that the wrapped version always
429    has exactly one character at the end, a ')'. Will that always be true?  */
430 #define RX_PRELEN(prog)		(RX_WRAPLEN(prog) - ((struct regexp *)SvANY(prog))->pre_prefix - 1)
431 #define RX_WRAPPED(prog)	SvPVX(prog)
432 #define RX_WRAPPED_const(prog)	SvPVX_const(prog)
433 #define RX_WRAPLEN(prog)	SvCUR(prog)
434 #define RX_CHECK_SUBSTR(prog)	(((struct regexp *)SvANY(prog))->check_substr)
435 #define RX_REFCNT(prog)		SvREFCNT(prog)
436 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
437 #  define RX_EXTFLAGS(prog)						\
438     (*({								\
439 	const REGEXP *const _rx_extflags = (prog);			\
440 	assert(SvTYPE(_rx_extflags) == SVt_REGEXP);			\
441 	&RXp_EXTFLAGS(SvANY(_rx_extflags));				\
442     }))
443 #  define RX_ENGINE(prog)						\
444     (*({								\
445 	const REGEXP *const _rx_engine = (prog);			\
446 	assert(SvTYPE(_rx_engine) == SVt_REGEXP);			\
447 	&SvANY(_rx_engine)->engine;					\
448     }))
449 #  define RX_SUBBEG(prog)						\
450     (*({								\
451 	const REGEXP *const _rx_subbeg = (prog);			\
452 	assert(SvTYPE(_rx_subbeg) == SVt_REGEXP);			\
453 	&SvANY(_rx_subbeg)->subbeg;					\
454     }))
455 #  define RX_OFFS(prog)							\
456     (*({								\
457 	const REGEXP *const _rx_offs = (prog);				\
458 	assert(SvTYPE(_rx_offs) == SVt_REGEXP);				\
459 	&SvANY(_rx_offs)->offs;						\
460     }))
461 #  define RX_NPARENS(prog)						\
462     (*({								\
463 	const REGEXP *const _rx_nparens = (prog);			\
464 	assert(SvTYPE(_rx_nparens) == SVt_REGEXP);			\
465 	&SvANY(_rx_nparens)->nparens;					\
466     }))
467 #else
468 #  define RX_EXTFLAGS(prog)	RXp_EXTFLAGS((struct regexp *)SvANY(prog))
469 #  define RX_ENGINE(prog)	(((struct regexp *)SvANY(prog))->engine)
470 #  define RX_SUBBEG(prog)	(((struct regexp *)SvANY(prog))->subbeg)
471 #  define RX_OFFS(prog)		(((struct regexp *)SvANY(prog))->offs)
472 #  define RX_NPARENS(prog)	(((struct regexp *)SvANY(prog))->nparens)
473 #endif
474 #define RX_SUBLEN(prog)		(((struct regexp *)SvANY(prog))->sublen)
475 #define RX_MINLEN(prog)		(((struct regexp *)SvANY(prog))->minlen)
476 #define RX_MINLENRET(prog)	(((struct regexp *)SvANY(prog))->minlenret)
477 #define RX_GOFS(prog)		(((struct regexp *)SvANY(prog))->gofs)
478 #define RX_LASTPAREN(prog)	(((struct regexp *)SvANY(prog))->lastparen)
479 #define RX_LASTCLOSEPAREN(prog)	(((struct regexp *)SvANY(prog))->lastcloseparen)
480 #define RX_SEEN_EVALS(prog)	(((struct regexp *)SvANY(prog))->seen_evals)
481 #define RX_SAVED_COPY(prog)	(((struct regexp *)SvANY(prog))->saved_copy)
482 
483 #endif /* PLUGGABLE_RE_EXTENSION */
484 
485 /* Stuff that needs to be included in the pluggable extension goes below here */
486 
487 #ifdef PERL_OLD_COPY_ON_WRITE
488 #define RX_MATCH_COPY_FREE(rx) \
489 	STMT_START {if (RX_SAVED_COPY(rx)) { \
490 	    SV_CHECK_THINKFIRST_COW_DROP(RX_SAVED_COPY(rx)); \
491 	} \
492 	if (RX_MATCH_COPIED(rx)) { \
493 	    Safefree(RX_SUBBEG(rx)); \
494 	    RX_MATCH_COPIED_off(rx); \
495 	}} STMT_END
496 #else
497 #define RX_MATCH_COPY_FREE(rx) \
498 	STMT_START {if (RX_MATCH_COPIED(rx)) { \
499 	    Safefree(RX_SUBBEG(rx)); \
500 	    RX_MATCH_COPIED_off(rx); \
501 	}} STMT_END
502 #endif
503 
504 #define RXp_MATCH_UTF8(prog)		(RXp_EXTFLAGS(prog) & RXf_MATCH_UTF8)
505 #define RX_MATCH_UTF8(prog)		(RX_EXTFLAGS(prog) & RXf_MATCH_UTF8)
506 #define RX_MATCH_UTF8_on(prog)		(RX_EXTFLAGS(prog) |= RXf_MATCH_UTF8)
507 #define RX_MATCH_UTF8_off(prog)		(RX_EXTFLAGS(prog) &= ~RXf_MATCH_UTF8)
508 #define RX_MATCH_UTF8_set(prog, t)	((t) \
509 			? (RX_MATCH_UTF8_on(prog), (PL_reg_match_utf8 = 1)) \
510 			: (RX_MATCH_UTF8_off(prog), (PL_reg_match_utf8 = 0)))
511 
512 /* Whether the pattern stored at RX_WRAPPED is in UTF-8  */
513 #define RX_UTF8(prog)			SvUTF8(prog)
514 
515 #define REXEC_COPY_STR	0x01		/* Need to copy the string. */
516 #define REXEC_CHECKED	0x02		/* check_substr already checked. */
517 #define REXEC_SCREAM	0x04		/* use scream table. */
518 #define REXEC_IGNOREPOS	0x08		/* \G matches at start. */
519 #define REXEC_NOT_FIRST	0x10		/* This is another iteration of //g. */
520 
521 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
522 #  define ReREFCNT_inc(re)						\
523     ({									\
524 	/* This is here to generate a casting warning if incorrect.  */	\
525 	REGEXP *const _rerefcnt_inc = (re);				\
526 	assert(SvTYPE(_rerefcnt_inc) == SVt_REGEXP);			\
527 	SvREFCNT_inc(_rerefcnt_inc);					\
528 	_rerefcnt_inc;							\
529     })
530 #  define ReREFCNT_dec(re)						\
531     ({									\
532 	/* This is here to generate a casting warning if incorrect.  */	\
533 	REGEXP *const _rerefcnt_dec = (re);				\
534 	SvREFCNT_dec(_rerefcnt_dec);					\
535     })
536 #else
537 #  define ReREFCNT_dec(re)	SvREFCNT_dec(re)
538 #  define ReREFCNT_inc(re)	((REGEXP *) SvREFCNT_inc(re))
539 #endif
540 
541 /* FIXME for plugins. */
542 
543 #define FBMcf_TAIL_DOLLAR	1
544 #define FBMcf_TAIL_DOLLARM	2
545 #define FBMcf_TAIL_Z		4
546 #define FBMcf_TAIL_z		8
547 #define FBMcf_TAIL		(FBMcf_TAIL_DOLLAR|FBMcf_TAIL_DOLLARM|FBMcf_TAIL_Z|FBMcf_TAIL_z)
548 
549 #define FBMrf_MULTILINE	1
550 
551 /* some basic information about the current match that is created by
552  * Perl_regexec_flags and then passed to regtry(), regmatch() etc */
553 
554 typedef struct {
555     REGEXP *prog;
556     char *bol;
557     char *till;
558     SV *sv;
559     char *ganch;
560     char *cutpoint;
561 } regmatch_info;
562 
563 
564 /* structures for holding and saving the state maintained by regmatch() */
565 
566 #ifndef MAX_RECURSE_EVAL_NOCHANGE_DEPTH
567 #define MAX_RECURSE_EVAL_NOCHANGE_DEPTH 1000
568 #endif
569 
570 typedef I32 CHECKPOINT;
571 
572 typedef struct regmatch_state {
573     int resume_state;		/* where to jump to on return */
574     char *locinput;		/* where to backtrack in string on failure */
575 
576     union {
577 
578 	/* this is a fake union member that matches the first element
579 	 * of each member that needs to store positive backtrack
580 	 * information */
581 	struct {
582 	    struct regmatch_state *prev_yes_state;
583 	} yes;
584 
585         /* branchlike members */
586         /* this is a fake union member that matches the first elements
587          * of each member that needs to behave like a branch */
588         struct {
589 	    /* this first element must match u.yes */
590 	    struct regmatch_state *prev_yes_state;
591 	    U32 lastparen;
592 	    CHECKPOINT cp;
593 
594         } branchlike;
595 
596 	struct {
597 	    /* the first elements must match u.branchlike */
598 	    struct regmatch_state *prev_yes_state;
599 	    U32 lastparen;
600 	    CHECKPOINT cp;
601 
602 	    regnode *next_branch; /* next branch node */
603 	} branch;
604 
605 	struct {
606 	    /* the first elements must match u.branchlike */
607 	    struct regmatch_state *prev_yes_state;
608 	    U32 lastparen;
609 	    CHECKPOINT cp;
610 
611 	    U32		accepted; /* how many accepting states left */
612 	    U16         *jump;  /* positive offsets from me */
613 	    regnode	*B;	/* node following the trie */
614 	    regnode	*me;	/* Which node am I - needed for jump tries*/
615 	    U8		*firstpos;/* pos in string of first trie match */
616 	    U32		firstchars;/* len in chars of firstpos from start */
617 	    U16		nextword;/* next word to try */
618 	    U16		topword; /* longest accepted word */
619 	    bool	longfold;/* saw a fold with a 1->n char mapping */
620 	} trie;
621 
622         /* special types - these members are used to store state for special
623            regops like eval, if/then, lookaround and the markpoint state */
624 	struct {
625 	    /* this first element must match u.yes */
626 	    struct regmatch_state *prev_yes_state;
627 	    struct regmatch_state *prev_eval;
628 	    struct regmatch_state *prev_curlyx;
629 	    REGEXP	*prev_rex;
630 	    U32		toggle_reg_flags; /* what bits in PL_reg_flags to
631 					    flip when transitioning between
632 					    inner and outer rexen */
633 	    CHECKPOINT	cp;	/* remember current savestack indexes */
634 	    CHECKPOINT	lastcp;
635 	    U32        close_paren; /* which close bracket is our end */
636 	    regnode	*B;	/* the node following us  */
637 	} eval;
638 
639 	struct {
640 	    /* this first element must match u.yes */
641 	    struct regmatch_state *prev_yes_state;
642 	    I32 wanted;
643 	    I32 logical;	/* saved copy of 'logical' var */
644 	    regnode  *me; /* the IFMATCH/SUSPEND/UNLESSM node  */
645 	} ifmatch; /* and SUSPEND/UNLESSM */
646 
647 	struct {
648 	    /* this first element must match u.yes */
649 	    struct regmatch_state *prev_yes_state;
650 	    struct regmatch_state *prev_mark;
651 	    SV* mark_name;
652 	    char *mark_loc;
653 	} mark;
654 
655 	struct {
656 	    int val;
657 	} keeper;
658 
659         /* quantifiers - these members are used for storing state for
660            for the regops used to implement quantifiers */
661 	struct {
662 	    /* this first element must match u.yes */
663 	    struct regmatch_state *prev_yes_state;
664 	    struct regmatch_state *prev_curlyx; /* previous cur_curlyx */
665 	    regnode	*me;	/* the CURLYX node  */
666 	    regnode	*B;	/* the B node in /A*B/  */
667 	    CHECKPOINT	cp;	/* remember current savestack index */
668 	    bool	minmod;
669 	    int		parenfloor;/* how far back to strip paren data */
670 
671 	    /* these two are modified by WHILEM */
672 	    int		count;	/* how many instances of A we've matched */
673 	    char	*lastloc;/* where previous A matched (0-len detect) */
674 	} curlyx;
675 
676 	struct {
677 	    /* this first element must match u.yes */
678 	    struct regmatch_state *prev_yes_state;
679 	    struct regmatch_state *save_curlyx;
680 	    CHECKPOINT	cp;	/* remember current savestack indexes */
681 	    CHECKPOINT	lastcp;
682 	    char	*save_lastloc;	/* previous curlyx.lastloc */
683 	    I32		cache_offset;
684 	    I32		cache_mask;
685 	} whilem;
686 
687 	struct {
688 	    /* this first element must match u.yes */
689 	    struct regmatch_state *prev_yes_state;
690 	    I32 c1, c2;		/* case fold search */
691 	    CHECKPOINT cp;
692 	    I32 alen;		/* length of first-matched A string */
693 	    I32 count;
694 	    bool minmod;
695 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
696 	    regnode *me;	/* the curlym node */
697 	} curlym;
698 
699 	struct {
700 	    U32 paren;
701 	    CHECKPOINT cp;
702 	    I32 c1, c2;		/* case fold search */
703 	    char *maxpos;	/* highest possible point in string to match */
704 	    char *oldloc;	/* the previous locinput */
705 	    int count;
706 	    int min, max;	/* {m,n} */
707 	    regnode *A, *B;	/* the nodes corresponding to /A*B/  */
708 	} curly; /* and CURLYN/PLUS/STAR */
709 
710     } u;
711 } regmatch_state;
712 
713 /* how many regmatch_state structs to allocate as a single slab.
714  * We do it in 4K blocks for efficiency. The "3" is 2 for the next/prev
715  * pointers, plus 1 for any mythical malloc overhead. */
716 
717 #define PERL_REGMATCH_SLAB_SLOTS \
718     ((4096 - 3 * sizeof (void*)) / sizeof(regmatch_state))
719 
720 typedef struct regmatch_slab {
721     regmatch_state states[PERL_REGMATCH_SLAB_SLOTS];
722     struct regmatch_slab *prev, *next;
723 } regmatch_slab;
724 
725 #define PL_reg_flags		PL_reg_state.re_state_reg_flags
726 #define PL_bostr		PL_reg_state.re_state_bostr
727 #define PL_reginput		PL_reg_state.re_state_reginput
728 #define PL_regeol		PL_reg_state.re_state_regeol
729 #define PL_regoffs		PL_reg_state.re_state_regoffs
730 #define PL_reglastparen		PL_reg_state.re_state_reglastparen
731 #define PL_reglastcloseparen	PL_reg_state.re_state_reglastcloseparen
732 #define PL_reg_start_tmp	PL_reg_state.re_state_reg_start_tmp
733 #define PL_reg_start_tmpl	PL_reg_state.re_state_reg_start_tmpl
734 #define PL_reg_eval_set		PL_reg_state.re_state_reg_eval_set
735 #define PL_reg_match_utf8	PL_reg_state.re_state_reg_match_utf8
736 #define PL_reg_magic		PL_reg_state.re_state_reg_magic
737 #define PL_reg_oldpos		PL_reg_state.re_state_reg_oldpos
738 #define PL_reg_oldcurpm		PL_reg_state.re_state_reg_oldcurpm
739 #define PL_reg_curpm		PL_reg_state.re_state_reg_curpm
740 #define PL_reg_oldsaved		PL_reg_state.re_state_reg_oldsaved
741 #define PL_reg_oldsavedlen	PL_reg_state.re_state_reg_oldsavedlen
742 #define PL_reg_maxiter		PL_reg_state.re_state_reg_maxiter
743 #define PL_reg_leftiter		PL_reg_state.re_state_reg_leftiter
744 #define PL_reg_poscache		PL_reg_state.re_state_reg_poscache
745 #define PL_reg_poscache_size	PL_reg_state.re_state_reg_poscache_size
746 #define PL_regsize		PL_reg_state.re_state_regsize
747 #define PL_reg_starttry		PL_reg_state.re_state_reg_starttry
748 #define PL_nrs			PL_reg_state.re_state_nrs
749 
750 struct re_save_state {
751     U32 re_state_reg_flags;		/* from regexec.c */
752     U32 re_state_reg_start_tmpl;	/* from regexec.c */
753     I32 re_state_reg_eval_set;		/* from regexec.c */
754     bool re_state_reg_match_utf8;	/* from regexec.c */
755     char *re_state_bostr;
756     char *re_state_reginput;		/* String-input pointer. */
757     char *re_state_regeol;		/* End of input, for $ check. */
758     regexp_paren_pair *re_state_regoffs;  /* Pointer to start/end pairs */
759     U32 *re_state_reglastparen;		/* Similarly for lastparen. */
760     U32 *re_state_reglastcloseparen;	/* Similarly for lastcloseparen. */
761     char **re_state_reg_start_tmp;	/* from regexec.c */
762     MAGIC *re_state_reg_magic;		/* from regexec.c */
763     PMOP *re_state_reg_oldcurpm;	/* from regexec.c */
764     PMOP *re_state_reg_curpm;		/* from regexec.c */
765     char *re_state_reg_oldsaved;	/* old saved substr during match */
766     STRLEN re_state_reg_oldsavedlen;	/* old length of saved substr during match */
767     STRLEN re_state_reg_poscache_size;	/* size of pos cache of WHILEM */
768     I32 re_state_reg_oldpos;		/* from regexec.c */
769     I32 re_state_reg_maxiter;		/* max wait until caching pos */
770     I32 re_state_reg_leftiter;		/* wait until caching pos */
771     U32 re_state_regsize;		/* from regexec.c */
772     char *re_state_reg_poscache;	/* cache of pos of WHILEM */
773     char *re_state_reg_starttry;	/* from regexec.c */
774 #ifdef PERL_OLD_COPY_ON_WRITE
775     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 */
776 #endif
777 };
778 
779 #define SAVESTACK_ALLOC_FOR_RE_SAVE_STATE \
780 	(1 + ((sizeof(struct re_save_state) - 1) / sizeof(*PL_savestack)))
781 
782 /*
783  * Local variables:
784  * c-indentation-style: bsd
785  * c-basic-offset: 4
786  * indent-tabs-mode: t
787  * End:
788  *
789  * ex: set ts=8 sts=4 sw=4 noet:
790  */
791