5 * "A fair jaw-cracker dwarf-language must be." --Samwise Gamgee
8 /* NOTE: this is derived from Henry Spencer's regexp code, and should not
9 * confused with the original package (see point 3 below). Thanks, Henry!
12 /* Additional note: this code is very heavily munged from Henry's version
13 * in places. In some spots I've traded clarity for efficiency, so don't
14 * blame Henry for some of the lack of readability.
17 /* The names of the functions have been changed from regcomp and
18 * regexec to pregcomp and pregexec in order to avoid conflicts
19 * with the POSIX routines of the same names.
24 * pregcomp and pregexec -- regsub and regerror are not used in perl
26 * Copyright (c) 1986 by University of Toronto.
27 * Written by Henry Spencer. Not derived from licensed software.
29 * Permission is granted to anyone to use this software for any
30 * purpose on any computer system, and to redistribute it freely,
31 * subject to the following restrictions:
33 * 1. The author is not responsible for the consequences of use of
34 * this software, no matter how awful, even if they arise
37 * 2. The origin of this software must not be misrepresented, either
38 * by explicit claim or by omission.
40 * 3. Altered versions must be plainly marked as such, and must not
41 * be misrepresented as being the original software.
44 **** Alterations to Henry's code are...
46 **** Copyright (c) 1991-1997, Larry Wall
48 **** You may distribute under the terms of either the GNU General Public
49 **** License or the Artistic License, as specified in the README file.
52 * Beware that some of this code is subtly aware of the way operator
53 * precedence is structured in regular expressions. Serious changes in
54 * regular-expression syntax might require a total rethink.
63 #endif /* USE_THREADS */
66 # if defined(BUGGY_MSC6)
67 /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
68 # pragma optimize("a",off)
69 /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
70 # pragma optimize("w",on )
71 # endif /* BUGGY_MSC6 */
78 #define ISMULT1(c) ((c) == '*' || (c) == '+' || (c) == '?')
79 #define ISMULT2(s) ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
80 ((*s) == '{' && regcurly(s)))
82 #define PERL_META "^$.[()|?+*\\"
84 #define META "^$.[()|?+*\\"
88 #undef SPSTART /* dratted cpp namespace... */
91 * Flags to be passed up and down.
93 #define WORST 0 /* Worst case. */
94 #define HASWIDTH 0x1 /* Known never to match null string. */
95 #define SIMPLE 0x2 /* Simple enough to be STAR/PLUS operand. */
96 #define SPSTART 0x4 /* Starts with * or +. */
97 #define TRYAGAIN 0x8 /* Weeded out a declaration. */
100 * Forward declarations for pregcomp()'s friends.
103 static char *reg _((I32, I32 *));
104 static char *reganode _((char, unsigned short));
105 static char *regatom _((I32 *));
106 static char *regbranch _((I32 *));
107 static void regc _((char));
108 static char *regclass _((void));
109 STATIC I32 regcurly _((char *));
110 static char *regnode _((char));
111 static char *regpiece _((I32 *));
112 static void reginsert _((char, char *));
113 static void regoptail _((char *, char *));
114 static void regset _((char *, I32));
115 static void regtail _((char *, char *));
116 static char* regwhite _((char *, char *));
117 static char* nextchar _((void));
120 - pregcomp - compile a regular expression into internal code
122 * We can't allocate space until we know how big the compiled form will be,
123 * but we can't compile it (and thus know how big it is) until we've got a
124 * place to put the code. So we cheat: we compile it twice, once with code
125 * generation turned off and size counting turned on, and once "for real".
126 * This also means that we don't allocate space until we are sure that the
127 * thing really will compile successfully, and we never have to move the
128 * code and thus invalidate pointers into it. (Note that it has to be in
129 * one piece because free() must be able to free it all.) [NB: not true in perl]
131 * Beware that the optimization-preparation code in here knows about some
132 * of the structure of the compiled regexp. [I'll say.]
135 pregcomp(exp,xend,pm)
142 register SV *longish;
145 register char *first;
153 #define MAX_REPEAT_DEPTH 12
157 } repeat_stack[MAX_REPEAT_DEPTH];
158 I32 repeat_depth = 0;
159 I32 repeat_count = 1; /* We start unmultiplied. */
162 croak("NULL regexp argument");
164 regprecomp = savepvn(exp, xend - exp);
165 regflags = pm->op_pmflags;
168 /* First pass: determine size, legality. */
176 if (reg(0, &flags) == NULL) {
177 Safefree(regprecomp);
182 /* Small enough for pointer-storage convention? */
183 if (regsize >= 32767L) /* Probably could be 65535L. */
184 FAIL("regexp too big");
186 /* Allocate space and initialize. */
187 Newc(1001, r, sizeof(regexp) + (unsigned)regsize, char, regexp);
189 FAIL("regexp out of space");
190 r->prelen = xend - exp;
191 r->precomp = regprecomp;
192 r->subbeg = r->subbase = NULL;
194 /* Second pass: emit code. */
199 regcode = r->program;
201 if (reg(0, &flags) == NULL)
204 /* Dig out information for optimizations. */
205 pm->op_pmflags = regflags;
206 r->regstart = Nullsv; /* Worst-case defaults. */
210 r->regstclass = Nullch;
211 r->naughty = regnaughty >= 10; /* Probably an expensive pattern. */
212 scan = r->program+1; /* First BRANCH. */
213 if (OP(regnext(scan)) == END) {/* Only one top-level choice. */
214 scan = NEXTOPER(scan);
217 while ((OP(first) == OPEN && (sawopen = 1)) ||
218 (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
219 (OP(first) == PLUS) ||
220 (OP(first) == MINMOD) ||
221 (regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
222 if (OP(first) == PLUS)
225 first += regarglen[(U8)OP(first)];
226 first = NEXTOPER(first);
229 /* Starting-point info. */
231 if (OP(first) == EXACT) {
232 r->regstart = newSVpv(OPERAND(first)+1,*OPERAND(first));
233 if (SvCUR(r->regstart) > !sawstudy)
234 fbm_compile(r->regstart);
235 (void)SvUPGRADE(r->regstart, SVt_PVBM);
237 else if (strchr(simple+2,OP(first)))
238 r->regstclass = first;
239 else if (regkind[(U8)OP(first)] == BOUND ||
240 regkind[(U8)OP(first)] == NBOUND)
241 r->regstclass = first;
242 else if (regkind[(U8)OP(first)] == BOL) {
243 r->reganch |= ROPT_ANCH_BOL;
244 first = NEXTOPER(first);
247 else if (OP(first) == GPOS) {
248 r->reganch |= ROPT_ANCH_GPOS;
249 first = NEXTOPER(first);
252 else if ((OP(first) == STAR &&
253 regkind[(U8)OP(NEXTOPER(first))] == ANY) &&
254 !(r->reganch & ROPT_ANCH) )
256 /* turn .* into ^.* with an implied $*=1 */
257 r->reganch |= ROPT_ANCH_BOL | ROPT_IMPLICIT;
258 first = NEXTOPER(first);
261 if (sawplus && (!sawopen || !regsawback))
262 r->reganch |= ROPT_SKIP; /* x+ must match 1st of run */
264 DEBUG_r(PerlIO_printf(Perl_debug_log, "first %d next %d offset %d\n",
265 OP(first), OP(NEXTOPER(first)), first - scan));
267 * If there's something expensive in the r.e., find the
268 * longest literal string that must appear and make it the
269 * regmust. Resolve ties in favor of later strings, since
270 * the regstart check works with the beginning of the r.e.
271 * and avoiding duplication strengthens checking. Not a
272 * strong reason, but sufficient in the absence of others.
273 * [Now we resolve ties in favor of the earlier string if
274 * it happens that curback has been invalidated, since the
275 * earlier string may buy us something the later one won't.]
277 longish = newSVpv("",0);
278 longest = newSVpv("",0);
284 while (OP(scan) != END) {
285 if (OP(scan) == BRANCH) {
286 if (OP(regnext(scan)) == BRANCH) {
288 while (OP(scan) == BRANCH)
289 scan = regnext(scan);
291 else /* single branch is ok */
292 scan = NEXTOPER(scan);
295 if (OP(scan) == UNLESSM) {
297 scan = regnext(scan);
300 if (OP(scan) == EXACT) {
304 while ((t = regnext(scan)) && OP(t) == CLOSE)
306 minlen += *OPERAND(first) * repeat_count;
307 if (curback - backish == len) {
308 sv_catpvn(longish, OPERAND(first)+1,
310 len += *OPERAND(first);
311 curback += *OPERAND(first);
312 first = regnext(scan);
314 else if (*OPERAND(first) >= len + (curback >= 0)) {
315 len = *OPERAND(first);
316 sv_setpvn(longish, OPERAND(first)+1,len);
319 first = regnext(scan);
322 curback += *OPERAND(first);
324 else if (strchr(varies,OP(scan))) {
328 if (repeat_depth < MAX_REPEAT_DEPTH
329 && ((OP(scan) == PLUS
331 && (next = NEXTOPER(scan)))
332 || (regkind[(U8)OP(scan)] == CURLY
333 && (tcount = ARG1(scan))
334 && (next = NEXTOPER(scan)+4))))
336 /* We treat (abc)+ as (abc)(abc)*. */
338 /* Mark the place to return back. */
339 repeat_stack[repeat_depth].opcode = regnext(scan);
340 repeat_stack[repeat_depth].count = repeat_count;
342 repeat_count *= tcount;
351 if (SvCUR(longish) > SvCUR(longest)) {
352 sv_setsv(longest,longish);
355 sv_setpvn(longish,"",0);
358 else if (strchr(simple,OP(scan))) {
360 minlen += repeat_count;
362 if (SvCUR(longish) > SvCUR(longest)) {
363 sv_setsv(longest,longish);
366 sv_setpvn(longish,"",0);
368 scan = regnext(scan);
369 if (!scan) { /* Go up PLUS or CURLY. */
371 croak("panic: re scan");
372 scan = repeat_stack[repeat_depth].opcode;
373 repeat_count = repeat_stack[repeat_depth].count;
374 /* Need to submit the longest string found: */
377 if (SvCUR(longish) > SvCUR(longest)) {
378 sv_setsv(longest,longish);
381 sv_setpvn(longish,"",0);
385 /* Prefer earlier on tie, unless we can tail match latter */
387 if (SvCUR(longish) + (first && regkind[(U8)OP(first)] == EOL)
390 sv_setsv(longest,longish);
394 sv_setpvn(longish,"",0);
397 || !fbm_instr((unsigned char*) SvPVX(r->regstart),
398 (unsigned char *) (SvPVX(r->regstart)
399 + SvCUR(r->regstart)),
402 r->regmust = longest;
405 r->regback = backest;
406 if (SvCUR(longest) > !(sawstudy ||
407 (first && regkind[(U8)OP(first)] == EOL)))
408 fbm_compile(r->regmust);
409 (void)SvUPGRADE(r->regmust, SVt_PVBM);
410 BmUSEFUL(r->regmust) = 100;
411 if (first && regkind[(U8)OP(first)] == EOL && SvCUR(longish))
412 SvTAIL_on(r->regmust);
415 SvREFCNT_dec(longest);
418 SvREFCNT_dec(longish);
421 r->nparens = regnpar - 1;
423 Newz(1002, r->startp, regnpar, char*);
424 Newz(1002, r->endp, regnpar, char*);
430 - reg - regular expression, i.e. main body or parenthesized thing
432 * Caller must absorb opening parenthesis.
434 * Combining parenthesis handling with the base level of regular expression
435 * is a trifle forced, but the need to tie the tails of the branches to what
436 * follows makes it hard to avoid.
440 I32 paren; /* Parenthesized? */
445 register char *ender = 0;
446 register I32 parno = 0;
449 *flagp = HASWIDTH; /* Tentatively. */
451 /* Make an OPEN node, if parenthesized. */
453 if (*regparse == '?') {
464 croak("Sequence (?%c...) not implemented", (int)paren);
467 while (*regparse && *regparse != ')')
469 if (*regparse != ')')
470 croak("Sequence (?#... not terminated");
476 while (*regparse && strchr("iogcmsx", *regparse))
477 pmflag(®flags, *regparse++);
478 if (*regparse != ')')
479 croak("Sequence (?%c...) not recognized", *regparse);
488 ret = reganode(OPEN, parno);
493 /* Pick up the branches, linking them together. */
494 br = regbranch(&flags);
498 regtail(ret, br); /* OPEN -> first. */
501 if (!(flags&HASWIDTH))
503 *flagp |= flags&SPSTART;
504 while (*regparse == '|') {
506 br = regbranch(&flags);
509 regtail(ret, br); /* BRANCH -> BRANCH. */
510 if (!(flags&HASWIDTH))
512 *flagp |= flags&SPSTART;
515 /* Make a closing node, and hook it on the end. */
518 ender = regnode(NOTHING);
521 ender = reganode(CLOSE, parno);
525 ender = regnode(SUCCEED);
529 ender = regnode(END);
534 /* Hook the tails of the branches to the closing node. */
535 for (br = ret; br != NULL; br = regnext(br))
536 regoptail(br, ender);
539 reginsert(IFMATCH,ret);
540 regtail(ret, regnode(NOTHING));
542 else if (paren == '!') {
543 reginsert(UNLESSM,ret);
544 regtail(ret, regnode(NOTHING));
547 /* Check for proper termination. */
548 if (paren && (regparse >= regxend || *nextchar() != ')')) {
549 FAIL("unmatched () in regexp");
550 } else if (!paren && regparse < regxend) {
551 if (*regparse == ')') {
552 FAIL("unmatched () in regexp");
554 FAIL("junk on end of regexp"); /* "Can't happen". */
562 - regbranch - one alternative of an | operator
564 * Implements the concatenation operator.
571 register char *chain;
572 register char *latest;
575 *flagp = WORST; /* Tentatively. */
577 ret = regnode(BRANCH);
581 while (regparse < regxend && *regparse != '|' && *regparse != ')') {
583 latest = regpiece(&flags);
584 if (latest == NULL) {
585 if (flags & TRYAGAIN)
589 *flagp |= flags&HASWIDTH;
590 if (chain == NULL) /* First piece. */
591 *flagp |= flags&SPSTART;
594 regtail(chain, latest);
598 if (chain == NULL) /* Loop ran zero times. */
599 (void) regnode(NOTHING);
605 - regpiece - something followed by possible [*+?]
607 * Note that the branching code sequences used for ? and the general cases
608 * of * and + are somewhat optimized: they use the same NOTHING node as
609 * both the endmarker for their branch list and the body of the last branch.
610 * It might seem that this node could be dispensed with entirely, but the
611 * endmarker role is not redundant.
621 char *origparse = regparse;
626 ret = regatom(&flags);
628 if (flags & TRYAGAIN)
634 if (op == '(' && regparse[1] == '?' && regparse[2] == '#') {
635 while (op && op != ')')
643 if (op == '{' && regcurly(regparse)) {
646 while (isDIGIT(*next) || *next == ',') {
655 if (*next == '}') { /* got one */
659 min = atoi(regparse);
665 if (!max && *maxpos != '0')
666 max = 32767; /* meaning "infinity" */
671 if ((flags&SIMPLE)) {
672 regnaughty += 2 + regnaughty / 2;
673 reginsert(CURLY, ret);
676 regnaughty += 4 + regnaughty; /* compound interest */
677 regtail(ret, regnode(WHILEM));
678 reginsert(CURLYX,ret);
679 regtail(ret, regnode(NOTHING));
683 *flagp = (WORST|HASWIDTH);
684 if (max && max < min)
685 croak("Can't do {n,m} with n > m");
686 if (regcode != ®dummy) {
688 *(unsigned short *)(ret+3) = min;
689 *(unsigned short *)(ret+5) = max;
691 ret[3] = min >> 8; ret[4] = min & 0377;
692 ret[5] = max >> 8; ret[6] = max & 0377;
705 if (!(flags&HASWIDTH) && op != '?')
706 FAIL("regexp *+ operand could be empty");
710 *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
712 if (op == '*' && (flags&SIMPLE)) {
713 reginsert(STAR, ret);
716 else if (op == '*') {
719 } else if (op == '+' && (flags&SIMPLE)) {
720 reginsert(PLUS, ret);
723 else if (op == '+') {
726 } else if (op == '?') {
731 if (dowarn && regcode != ®dummy && !(flags&HASWIDTH) && max > 10000) {
732 warn("%.*s matches null string many times",
733 regparse - origparse, origparse);
736 if (*regparse == '?') {
738 reginsert(MINMOD, ret);
740 regtail(ret, ret + 4);
742 regtail(ret, ret + 3);
745 if (ISMULT2(regparse))
746 FAIL("nested *?+ in regexp");
752 - regatom - the lowest level
754 * Optimization: gobbles an entire sequence of ordinary characters so that
755 * it can turn them into a single node, which is smaller to store and
756 * faster to run. Backslashed characters are exceptions, each becoming a
757 * separate node; the code is simpler that way and it's not worth fixing.
759 * [Yes, it is worth fixing, some scripts can run twice the speed.]
765 register char *ret = 0;
768 *flagp = WORST; /* Tentatively. */
774 if (regflags & PMf_MULTILINE)
776 else if (regflags & PMf_SINGLELINE)
783 if (regflags & PMf_MULTILINE)
785 else if (regflags & PMf_SINGLELINE)
792 if (regflags & PMf_SINGLELINE)
797 *flagp |= HASWIDTH|SIMPLE;
802 *flagp |= HASWIDTH|SIMPLE;
806 ret = reg(1, &flags);
808 if (flags & TRYAGAIN)
812 *flagp |= flags&(HASWIDTH|SPSTART);
816 if (flags & TRYAGAIN) {
820 croak("internal urp in regexp at /%s/", regparse);
821 /* Supposed to be caught earlier. */
824 if (!regcurly(regparse)) {
832 FAIL("?+*{} follows nothing in regexp");
835 switch (*++regparse) {
852 ret = regnode((regflags & PMf_LOCALE) ? ALNUML : ALNUM);
853 *flagp |= HASWIDTH|SIMPLE;
857 ret = regnode((regflags & PMf_LOCALE) ? NALNUML : NALNUM);
858 *flagp |= HASWIDTH|SIMPLE;
862 ret = regnode((regflags & PMf_LOCALE) ? BOUNDL : BOUND);
867 ret = regnode((regflags & PMf_LOCALE) ? NBOUNDL : NBOUND);
872 ret = regnode((regflags & PMf_LOCALE) ? SPACEL : SPACE);
873 *flagp |= HASWIDTH|SIMPLE;
877 ret = regnode((regflags & PMf_LOCALE) ? NSPACEL : NSPACE);
878 *flagp |= HASWIDTH|SIMPLE;
882 ret = regnode(DIGIT);
883 *flagp |= HASWIDTH|SIMPLE;
887 ret = regnode(NDIGIT);
888 *flagp |= HASWIDTH|SIMPLE;
901 case '1': case '2': case '3': case '4':
902 case '5': case '6': case '7': case '8': case '9':
904 I32 num = atoi(regparse);
906 if (num > 9 && num >= regnpar)
910 ret = reganode(REF, num);
912 while (isDIGIT(*regparse))
920 if (regparse >= regxend)
921 FAIL("trailing \\ in regexp");
929 if (regflags & PMf_EXTENDED) {
930 while (regparse < regxend && *regparse != '\n') regparse++;
931 if (regparse < regxend)
946 ret = regnode((regflags & PMf_FOLD)
947 ? ((regflags & PMf_LOCALE) ? EXACTFL : EXACTF)
949 regc(0); /* save spot for len */
950 for (len = 0, p = regparse - 1;
951 len < 127 && p < regxend;
956 if (regflags & PMf_EXTENDED)
957 p = regwhite(p, regxend);
1007 ender = scan_hex(++p, 2, &numlen);
1012 ender = UCHARAT(p++);
1013 ender = toCTRL(ender);
1015 case '0': case '1': case '2': case '3':case '4':
1016 case '5': case '6': case '7': case '8':case '9':
1018 (isDIGIT(p[1]) && atoi(p) >= regnpar) ) {
1019 ender = scan_oct(p, 3, &numlen);
1029 FAIL("trailing \\ in regexp");
1040 if (regflags & PMf_EXTENDED)
1041 p = regwhite(p, regxend);
1042 if (ISMULT2(p)) { /* Back off on ?+*. */
1057 FAIL("internal disaster in regexp");
1062 if (regcode != ®dummy)
1063 *OPERAND(ret) = len;
1080 else if (*p == '#') {
1083 } while (p < e && *p != '\n');
1096 if (opnd == ®dummy)
1099 opnd[1 + (c >> 3)] |= (1 << (c & 7));
1105 register char *opnd;
1107 register I32 lastclass = 1234;
1108 register I32 range = 0;
1113 ret = regnode(ANYOF);
1115 for (class = 0; class < 33; class++)
1117 if (*regparse == '^') { /* Complement of range. */
1120 if (opnd != ®dummy)
1121 *opnd |= ANYOF_INVERT;
1123 if (opnd != ®dummy) {
1124 if (regflags & PMf_FOLD)
1125 *opnd |= ANYOF_FOLD;
1126 if (regflags & PMf_LOCALE)
1127 *opnd |= ANYOF_LOCALE;
1129 if (*regparse == ']' || *regparse == '-')
1130 goto skipcond; /* allow 1st char to be ] or - */
1131 while (regparse < regxend && *regparse != ']') {
1133 class = UCHARAT(regparse++);
1134 if (class == '\\') {
1135 class = UCHARAT(regparse++);
1138 if (regflags & PMf_LOCALE) {
1139 if (opnd != ®dummy)
1140 *opnd |= ANYOF_ALNUML;
1143 for (class = 0; class < 256; class++)
1145 regset(opnd, class);
1150 if (regflags & PMf_LOCALE) {
1151 if (opnd != ®dummy)
1152 *opnd |= ANYOF_NALNUML;
1155 for (class = 0; class < 256; class++)
1156 if (!isALNUM(class))
1157 regset(opnd, class);
1162 if (regflags & PMf_LOCALE) {
1163 if (opnd != ®dummy)
1164 *opnd |= ANYOF_SPACEL;
1167 for (class = 0; class < 256; class++)
1169 regset(opnd, class);
1174 if (regflags & PMf_LOCALE) {
1175 if (opnd != ®dummy)
1176 *opnd |= ANYOF_NSPACEL;
1179 for (class = 0; class < 256; class++)
1180 if (!isSPACE(class))
1181 regset(opnd, class);
1186 for (class = '0'; class <= '9'; class++)
1187 regset(opnd, class);
1191 for (class = 0; class < '0'; class++)
1192 regset(opnd, class);
1193 for (class = '9' + 1; class < 256; class++)
1194 regset(opnd, class);
1219 class = scan_hex(regparse, 2, &numlen);
1223 class = UCHARAT(regparse++);
1224 class = toCTRL(class);
1226 case '0': case '1': case '2': case '3': case '4':
1227 case '5': case '6': case '7': case '8': case '9':
1228 class = scan_oct(--regparse, 3, &numlen);
1234 if (lastclass > class)
1235 FAIL("invalid [] range in regexp");
1240 if (*regparse == '-' && regparse+1 < regxend &&
1241 regparse[1] != ']') {
1244 continue; /* do it next time */
1247 for ( ; lastclass <= class; lastclass++)
1248 regset(opnd, lastclass);
1251 if (*regparse != ']')
1252 FAIL("unmatched [] in regexp");
1260 char* retval = regparse++;
1263 if (*regparse == '(' && regparse[1] == '?' &&
1264 regparse[2] == '#') {
1265 while (*regparse && *regparse != ')')
1270 if (regflags & PMf_EXTENDED) {
1271 if (isSPACE(*regparse)) {
1275 else if (*regparse == '#') {
1276 while (*regparse && *regparse != '\n')
1287 - regnode - emit a node
1289 #ifdef CAN_PROTOTYPE
1290 static char * /* Location. */
1293 static char * /* Location. */
1302 if (ret == ®dummy) {
1313 if (!((long)ret & 1))
1319 *ptr++ = '\0'; /* Null "next" pointer. */
1327 - reganode - emit a node with an argument
1329 #ifdef CAN_PROTOTYPE
1330 static char * /* Location. */
1331 reganode(char op, unsigned short arg)
1333 static char * /* Location. */
1343 if (ret == ®dummy) {
1354 if (!((long)ret & 1))
1360 *ptr++ = '\0'; /* Null "next" pointer. */
1363 *(unsigned short *)(ret+3) = arg;
1365 ret[3] = arg >> 8; ret[4] = arg & 0377;
1374 - regc - emit (if appropriate) a byte of code
1376 #ifdef CAN_PROTOTYPE
1385 if (regcode != ®dummy)
1392 - reginsert - insert an operator in front of already-emitted operand
1394 * Means relocating the operand.
1396 #ifdef CAN_PROTOTYPE
1398 reginsert(char op, char *opnd)
1408 register char *place;
1409 register int offset = (regkind[(U8)op] == CURLY ? 4 : 0);
1411 if (regcode == ®dummy) {
1413 regsize += 4 + offset;
1415 regsize += 3 + offset;
1422 regcode += 4 + offset;
1424 regcode += 3 + offset;
1430 place = opnd; /* Op node, where operand used to be. */
1434 while (offset-- > 0)
1442 - regtail - set the next-pointer at the end of a node chain
1449 register char *scan;
1450 register char *temp;
1451 register I32 offset;
1456 /* Find last node. */
1459 temp = regnext(scan);
1466 offset = val - scan;
1468 *(short*)(scan+1) = offset;
1473 if (OP(scan) == BACK)
1474 offset = scan - val;
1476 offset = val - scan;
1477 *(scan+1) = (offset>>8)&0377;
1478 *(scan+2) = offset&0377;
1483 - regoptail - regtail on operand of first argument; nop if operandless
1490 /* "Operandless" and "op != BRANCH" are synonymous in practice. */
1491 if (p == NULL || p == ®dummy || regkind[(U8)OP(p)] != BRANCH)
1493 regtail(NEXTOPER(p), val);
1497 - regcurly - a little FSA that accepts {\d+,?\d*}
1521 - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
1528 register char op = EXACT; /* Arbitrary non-END op. */
1529 register char *next;
1530 SV *sv = sv_newmortal();
1533 while (op != END) { /* While that wasn't END last time... */
1541 PerlIO_printf(Perl_debug_log, "%2d%s", s - r->program, SvPVX(sv));
1543 s += regarglen[(U8)op];
1544 if (next == NULL) /* Next ptr. */
1545 PerlIO_printf(Perl_debug_log, "(0)");
1547 PerlIO_printf(Perl_debug_log, "(%d)", (s-r->program)+(next-s));
1552 if (regkind[(U8)op] == EXACT) {
1553 /* Literal string, where present. */
1555 (void)PerlIO_putc(Perl_debug_log, ' ');
1556 (void)PerlIO_putc(Perl_debug_log, '<');
1557 while (*s != '\0') {
1558 (void)PerlIO_putc(Perl_debug_log,*s);
1561 (void)PerlIO_putc(Perl_debug_log, '>');
1564 (void)PerlIO_putc(Perl_debug_log, '\n');
1567 /* Header fields of interest. */
1569 PerlIO_printf(Perl_debug_log, "start `%s' ", SvPVX(r->regstart));
1570 if (r->regstclass) {
1571 regprop(sv, r->regstclass);
1572 PerlIO_printf(Perl_debug_log, "stclass `%s' ", SvPVX(sv));
1574 if (r->reganch & ROPT_ANCH) {
1575 PerlIO_printf(Perl_debug_log, "anchored");
1576 if (r->reganch & ROPT_ANCH_BOL)
1577 PerlIO_printf(Perl_debug_log, "(BOL)");
1578 if (r->reganch & ROPT_ANCH_GPOS)
1579 PerlIO_printf(Perl_debug_log, "(GPOS)");
1580 PerlIO_putc(Perl_debug_log, ' ');
1582 if (r->reganch & ROPT_SKIP)
1583 PerlIO_printf(Perl_debug_log, "plus ");
1584 if (r->reganch & ROPT_IMPLICIT)
1585 PerlIO_printf(Perl_debug_log, "implicit ");
1586 if (r->regmust != NULL)
1587 PerlIO_printf(Perl_debug_log, "must have \"%s\" back %ld ", SvPVX(r->regmust),
1589 PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
1590 PerlIO_printf(Perl_debug_log, "\n");
1594 - regprop - printable representation of opcode
1601 register char *p = 0;
1666 sv_catpvf(sv, "CURLY {%d,%d}", ARG1(o), ARG2(o));
1669 sv_catpvf(sv, "CURLYX {%d,%d}", ARG1(o), ARG2(o));
1672 sv_catpvf(sv, "REF%d", ARG1(o));
1675 sv_catpvf(sv, "OPEN%d", ARG1(o));
1678 sv_catpvf(sv, "CLOSE%d", ARG1(o));
1736 FAIL("corrupted regexp opcode");
1741 #endif /* DEBUGGING */
1750 Safefree(r->precomp);
1751 r->precomp = Nullch;
1754 Safefree(r->subbase);
1755 r->subbase = Nullch;
1758 SvREFCNT_dec(r->regmust);
1759 r->regmust = Nullsv;
1762 SvREFCNT_dec(r->regstart);
1763 r->regstart = Nullsv;
1765 Safefree(r->startp);