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.
62 # if defined(BUGGY_MSC6)
63 /* MSC 6.00A breaks on op/regexp.t test 85 unless we turn this off */
64 # pragma optimize("a",off)
65 /* But MSC 6.00A is happy with 'w', for aliases only across function calls*/
66 # pragma optimize("w",on )
67 # endif /* BUGGY_MSC6 */
74 #define ISMULT1(c) ((c) == '*' || (c) == '+' || (c) == '?')
75 #define ISMULT2(s) ((*s) == '*' || (*s) == '+' || (*s) == '?' || \
76 ((*s) == '{' && regcurly(s)))
78 #define PERL_META "^$.[()|?+*\\"
80 #define META "^$.[()|?+*\\"
84 #undef SPSTART /* dratted cpp namespace... */
87 * Flags to be passed up and down.
89 #define WORST 0 /* Worst case. */
90 #define HASWIDTH 0x1 /* Known never to match null string. */
91 #define SIMPLE 0x2 /* Simple enough to be STAR/PLUS operand. */
92 #define SPSTART 0x4 /* Starts with * or +. */
93 #define TRYAGAIN 0x8 /* Weeded out a declaration. */
96 * Forward declarations for pregcomp()'s friends.
99 static char *reg _((I32, I32 *));
100 static char *reganode _((char, unsigned short));
101 static char *regatom _((I32 *));
102 static char *regbranch _((I32 *));
103 static void regc _((char));
104 static char *regclass _((void));
105 STATIC I32 regcurly _((char *));
106 static char *regnode _((char));
107 static char *regpiece _((I32 *));
108 static void reginsert _((char, char *));
109 static void regoptail _((char *, char *));
110 static void regset _((char *, I32));
111 static void regtail _((char *, char *));
112 static char* nextchar _((void));
115 - pregcomp - compile a regular expression into internal code
117 * We can't allocate space until we know how big the compiled form will be,
118 * but we can't compile it (and thus know how big it is) until we've got a
119 * place to put the code. So we cheat: we compile it twice, once with code
120 * generation turned off and size counting turned on, and once "for real".
121 * This also means that we don't allocate space until we are sure that the
122 * thing really will compile successfully, and we never have to move the
123 * code and thus invalidate pointers into it. (Note that it has to be in
124 * one piece because free() must be able to free it all.) [NB: not true in perl]
126 * Beware that the optimization-preparation code in here knows about some
127 * of the structure of the compiled regexp. [I'll say.]
130 pregcomp(exp,xend,pm)
137 register SV *longish;
140 register char *first;
148 #define MAX_REPEAT_DEPTH 12
152 } repeat_stack[MAX_REPEAT_DEPTH];
153 I32 repeat_depth = 0;
154 I32 repeat_count = 1; /* We start unmultiplied. */
157 croak("NULL regexp argument");
159 regprecomp = savepvn(exp, xend - exp);
160 regflags = pm->op_pmflags;
163 /* First pass: determine size, legality. */
171 if (reg(0, &flags) == NULL) {
172 Safefree(regprecomp);
177 /* Small enough for pointer-storage convention? */
178 if (regsize >= 32767L) /* Probably could be 65535L. */
179 FAIL("regexp too big");
181 /* Allocate space and initialize. */
182 Newc(1001, r, sizeof(regexp) + (unsigned)regsize, char, regexp);
184 FAIL("regexp out of space");
185 r->prelen = xend - exp;
186 r->precomp = regprecomp;
187 r->subbeg = r->subbase = NULL;
189 /* Second pass: emit code. */
194 regcode = r->program;
196 if (reg(0, &flags) == NULL)
199 /* Dig out information for optimizations. */
200 pm->op_pmflags = regflags;
201 r->regstart = Nullsv; /* Worst-case defaults. */
205 r->regstclass = Nullch;
206 r->naughty = regnaughty >= 10; /* Probably an expensive pattern. */
207 scan = r->program+1; /* First BRANCH. */
208 if (OP(regnext(scan)) == END) {/* Only one top-level choice. */
209 scan = NEXTOPER(scan);
212 while ((OP(first) == OPEN && (sawopen = 1)) ||
213 (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) ||
214 (OP(first) == PLUS) ||
215 (OP(first) == MINMOD) ||
216 (regkind[(U8)OP(first)] == CURLY && ARG1(first) > 0) ) {
217 if (OP(first) == PLUS)
220 first += regarglen[(U8)OP(first)];
221 first = NEXTOPER(first);
224 /* Starting-point info. */
226 if (OP(first) == EXACT) {
227 r->regstart = newSVpv(OPERAND(first)+1,*OPERAND(first));
228 if (SvCUR(r->regstart) > !sawstudy)
229 fbm_compile(r->regstart);
230 (void)SvUPGRADE(r->regstart, SVt_PVBM);
232 else if (strchr(simple+2,OP(first)))
233 r->regstclass = first;
234 else if (regkind[(U8)OP(first)] == BOUND ||
235 regkind[(U8)OP(first)] == NBOUND)
236 r->regstclass = first;
237 else if (regkind[(U8)OP(first)] == BOL) {
238 r->reganch |= ROPT_ANCH_BOL;
239 first = NEXTOPER(first);
242 else if (OP(first) == GPOS) {
243 r->reganch |= ROPT_ANCH_GPOS;
244 first = NEXTOPER(first);
247 else if ((OP(first) == STAR &&
248 regkind[(U8)OP(NEXTOPER(first))] == ANY) &&
249 !(r->reganch & ROPT_ANCH) )
251 /* turn .* into ^.* with an implied $*=1 */
252 r->reganch |= ROPT_ANCH_BOL | ROPT_IMPLICIT;
253 first = NEXTOPER(first);
256 if (sawplus && (!sawopen || !regsawback))
257 r->reganch |= ROPT_SKIP; /* x+ must match 1st of run */
259 DEBUG_r(PerlIO_printf(Perl_debug_log, "first %d next %d offset %d\n",
260 OP(first), OP(NEXTOPER(first)), first - scan));
262 * If there's something expensive in the r.e., find the
263 * longest literal string that must appear and make it the
264 * regmust. Resolve ties in favor of later strings, since
265 * the regstart check works with the beginning of the r.e.
266 * and avoiding duplication strengthens checking. Not a
267 * strong reason, but sufficient in the absence of others.
268 * [Now we resolve ties in favor of the earlier string if
269 * it happens that curback has been invalidated, since the
270 * earlier string may buy us something the later one won't.]
272 longish = newSVpv("",0);
273 longest = newSVpv("",0);
279 while (OP(scan) != END) {
280 if (OP(scan) == BRANCH) {
281 if (OP(regnext(scan)) == BRANCH) {
283 while (OP(scan) == BRANCH)
284 scan = regnext(scan);
286 else /* single branch is ok */
287 scan = NEXTOPER(scan);
290 if (OP(scan) == UNLESSM) {
292 scan = regnext(scan);
295 if (OP(scan) == EXACT) {
299 while ((t = regnext(scan)) && OP(t) == CLOSE)
301 minlen += *OPERAND(first) * repeat_count;
302 if (curback - backish == len) {
303 sv_catpvn(longish, OPERAND(first)+1,
305 len += *OPERAND(first);
306 curback += *OPERAND(first);
307 first = regnext(scan);
309 else if (*OPERAND(first) >= len + (curback >= 0)) {
310 len = *OPERAND(first);
311 sv_setpvn(longish, OPERAND(first)+1,len);
314 first = regnext(scan);
317 curback += *OPERAND(first);
319 else if (strchr(varies,OP(scan))) {
323 if (repeat_depth < MAX_REPEAT_DEPTH
324 && ((OP(scan) == PLUS
326 && (next = NEXTOPER(scan)))
327 || (regkind[(U8)OP(scan)] == CURLY
328 && (tcount = ARG1(scan))
329 && (next = NEXTOPER(scan)+4))))
331 /* We treat (abc)+ as (abc)(abc)*. */
333 /* Mark the place to return back. */
334 repeat_stack[repeat_depth].opcode = regnext(scan);
335 repeat_stack[repeat_depth].count = repeat_count;
337 repeat_count *= tcount;
346 if (SvCUR(longish) > SvCUR(longest)) {
347 sv_setsv(longest,longish);
350 sv_setpvn(longish,"",0);
353 else if (strchr(simple,OP(scan))) {
355 minlen += repeat_count;
357 if (SvCUR(longish) > SvCUR(longest)) {
358 sv_setsv(longest,longish);
361 sv_setpvn(longish,"",0);
363 scan = regnext(scan);
364 if (!scan) { /* Go up PLUS or CURLY. */
366 croak("panic: re scan");
367 scan = repeat_stack[repeat_depth].opcode;
368 repeat_count = repeat_stack[repeat_depth].count;
369 /* Need to submit the longest string found: */
372 if (SvCUR(longish) > SvCUR(longest)) {
373 sv_setsv(longest,longish);
376 sv_setpvn(longish,"",0);
380 /* Prefer earlier on tie, unless we can tail match latter */
382 if (SvCUR(longish) + (first && regkind[(U8)OP(first)] == EOL)
385 sv_setsv(longest,longish);
389 sv_setpvn(longish,"",0);
392 || !fbm_instr((unsigned char*) SvPVX(r->regstart),
393 (unsigned char *) (SvPVX(r->regstart)
394 + SvCUR(r->regstart)),
397 r->regmust = longest;
400 r->regback = backest;
401 if (SvCUR(longest) > !(sawstudy ||
402 (first && regkind[(U8)OP(first)] == EOL)))
403 fbm_compile(r->regmust);
404 (void)SvUPGRADE(r->regmust, SVt_PVBM);
405 BmUSEFUL(r->regmust) = 100;
406 if (first && regkind[(U8)OP(first)] == EOL && SvCUR(longish))
407 SvTAIL_on(r->regmust);
410 SvREFCNT_dec(longest);
413 SvREFCNT_dec(longish);
416 r->nparens = regnpar - 1;
418 Newz(1002, r->startp, regnpar, char*);
419 Newz(1002, r->endp, regnpar, char*);
425 - reg - regular expression, i.e. main body or parenthesized thing
427 * Caller must absorb opening parenthesis.
429 * Combining parenthesis handling with the base level of regular expression
430 * is a trifle forced, but the need to tie the tails of the branches to what
431 * follows makes it hard to avoid.
435 I32 paren; /* Parenthesized? */
440 register char *ender = 0;
441 register I32 parno = 0;
444 *flagp = HASWIDTH; /* Tentatively. */
446 /* Make an OPEN node, if parenthesized. */
448 if (*regparse == '?') {
459 croak("Sequence (?%c...) not implemented", (int)paren);
462 while (*regparse && *regparse != ')')
464 if (*regparse != ')')
465 croak("Sequence (?#... not terminated");
471 while (*regparse && strchr("iogmsx", *regparse))
472 pmflag(®flags, *regparse++);
473 if (*regparse != ')')
474 croak("Sequence (?%c...) not recognized", *regparse);
483 ret = reganode(OPEN, parno);
488 /* Pick up the branches, linking them together. */
489 br = regbranch(&flags);
493 regtail(ret, br); /* OPEN -> first. */
496 if (!(flags&HASWIDTH))
498 *flagp |= flags&SPSTART;
499 while (*regparse == '|') {
501 br = regbranch(&flags);
504 regtail(ret, br); /* BRANCH -> BRANCH. */
505 if (!(flags&HASWIDTH))
507 *flagp |= flags&SPSTART;
510 /* Make a closing node, and hook it on the end. */
513 ender = regnode(NOTHING);
516 ender = reganode(CLOSE, parno);
520 ender = regnode(SUCCEED);
524 ender = regnode(END);
529 /* Hook the tails of the branches to the closing node. */
530 for (br = ret; br != NULL; br = regnext(br))
531 regoptail(br, ender);
534 reginsert(IFMATCH,ret);
535 regtail(ret, regnode(NOTHING));
537 else if (paren == '!') {
538 reginsert(UNLESSM,ret);
539 regtail(ret, regnode(NOTHING));
542 /* Check for proper termination. */
543 if (paren && (regparse >= regxend || *nextchar() != ')')) {
544 FAIL("unmatched () in regexp");
545 } else if (!paren && regparse < regxend) {
546 if (*regparse == ')') {
547 FAIL("unmatched () in regexp");
549 FAIL("junk on end of regexp"); /* "Can't happen". */
557 - regbranch - one alternative of an | operator
559 * Implements the concatenation operator.
566 register char *chain;
567 register char *latest;
570 *flagp = WORST; /* Tentatively. */
572 ret = regnode(BRANCH);
576 while (regparse < regxend && *regparse != '|' && *regparse != ')') {
578 latest = regpiece(&flags);
579 if (latest == NULL) {
580 if (flags & TRYAGAIN)
584 *flagp |= flags&HASWIDTH;
585 if (chain == NULL) /* First piece. */
586 *flagp |= flags&SPSTART;
589 regtail(chain, latest);
593 if (chain == NULL) /* Loop ran zero times. */
594 (void) regnode(NOTHING);
600 - regpiece - something followed by possible [*+?]
602 * Note that the branching code sequences used for ? and the general cases
603 * of * and + are somewhat optimized: they use the same NOTHING node as
604 * both the endmarker for their branch list and the body of the last branch.
605 * It might seem that this node could be dispensed with entirely, but the
606 * endmarker role is not redundant.
616 char *origparse = regparse;
621 ret = regatom(&flags);
623 if (flags & TRYAGAIN)
629 if (op == '(' && regparse[1] == '?' && regparse[2] == '#') {
630 while (op && op != ')')
638 if (op == '{' && regcurly(regparse)) {
641 while (isDIGIT(*next) || *next == ',') {
650 if (*next == '}') { /* got one */
654 min = atoi(regparse);
660 if (!max && *maxpos != '0')
661 max = 32767; /* meaning "infinity" */
666 if ((flags&SIMPLE)) {
667 regnaughty += 2 + regnaughty / 2;
668 reginsert(CURLY, ret);
671 regnaughty += 4 + regnaughty; /* compound interest */
672 regtail(ret, regnode(WHILEM));
673 reginsert(CURLYX,ret);
674 regtail(ret, regnode(NOTHING));
678 *flagp = (WORST|HASWIDTH);
679 if (max && max < min)
680 croak("Can't do {n,m} with n > m");
681 if (regcode != ®dummy) {
683 *(unsigned short *)(ret+3) = min;
684 *(unsigned short *)(ret+5) = max;
686 ret[3] = min >> 8; ret[4] = min & 0377;
687 ret[5] = max >> 8; ret[6] = max & 0377;
701 *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
703 if (op == '*' && (flags&SIMPLE)) {
704 reginsert(STAR, ret);
707 else if (op == '*') {
710 } else if (op == '+' && (flags&SIMPLE)) {
711 reginsert(PLUS, ret);
714 else if (op == '+') {
717 } else if (op == '?') {
722 if (dowarn && regcode != ®dummy && !(flags&HASWIDTH) && max > 10000) {
723 warn("%.*s matches null string many times",
724 regparse - origparse, origparse);
727 if (*regparse == '?') {
729 reginsert(MINMOD, ret);
731 regtail(ret, ret + 4);
733 regtail(ret, ret + 3);
736 if (ISMULT2(regparse))
737 FAIL("nested *?+ in regexp");
743 - regatom - the lowest level
745 * Optimization: gobbles an entire sequence of ordinary characters so that
746 * it can turn them into a single node, which is smaller to store and
747 * faster to run. Backslashed characters are exceptions, each becoming a
748 * separate node; the code is simpler that way and it's not worth fixing.
750 * [Yes, it is worth fixing, some scripts can run twice the speed.]
756 register char *ret = 0;
759 *flagp = WORST; /* Tentatively. */
765 if (regflags & PMf_MULTILINE)
767 else if (regflags & PMf_SINGLELINE)
774 if (regflags & PMf_MULTILINE)
776 else if (regflags & PMf_SINGLELINE)
783 if (regflags & PMf_SINGLELINE)
788 *flagp |= HASWIDTH|SIMPLE;
793 *flagp |= HASWIDTH|SIMPLE;
797 ret = reg(1, &flags);
799 if (flags & TRYAGAIN)
803 *flagp |= flags&(HASWIDTH|SPSTART);
807 if (flags & TRYAGAIN) {
811 croak("internal urp in regexp at /%s/", regparse);
812 /* Supposed to be caught earlier. */
815 if (!regcurly(regparse)) {
823 FAIL("?+*{} follows nothing in regexp");
826 switch (*++regparse) {
843 ret = regnode((regflags & PMf_LOCALE) ? ALNUML : ALNUM);
844 *flagp |= HASWIDTH|SIMPLE;
848 ret = regnode((regflags & PMf_LOCALE) ? NALNUML : NALNUM);
849 *flagp |= HASWIDTH|SIMPLE;
853 ret = regnode((regflags & PMf_LOCALE) ? BOUNDL : BOUND);
858 ret = regnode((regflags & PMf_LOCALE) ? NBOUNDL : NBOUND);
863 ret = regnode((regflags & PMf_LOCALE) ? SPACEL : SPACE);
864 *flagp |= HASWIDTH|SIMPLE;
868 ret = regnode((regflags & PMf_LOCALE) ? NSPACEL : NSPACE);
869 *flagp |= HASWIDTH|SIMPLE;
873 ret = regnode(DIGIT);
874 *flagp |= HASWIDTH|SIMPLE;
878 ret = regnode(NDIGIT);
879 *flagp |= HASWIDTH|SIMPLE;
892 case '1': case '2': case '3': case '4':
893 case '5': case '6': case '7': case '8': case '9':
895 I32 num = atoi(regparse);
897 if (num > 9 && num >= regnpar)
901 ret = reganode(REF, num);
903 while (isDIGIT(*regparse))
911 if (regparse >= regxend)
912 FAIL("trailing \\ in regexp");
920 if (regflags & PMf_EXTENDED) {
921 while (regparse < regxend && *regparse != '\n') regparse++;
922 if (regparse < regxend)
937 ret = regnode((regflags & PMf_FOLD)
938 ? ((regflags & PMf_LOCALE) ? EXACTFL : EXACTF)
940 regc(0); /* save spot for len */
941 for (len = 0, p = regparse - 1;
942 len < 127 && p < regxend;
995 ender = scan_hex(++p, 2, &numlen);
1000 ender = UCHARAT(p++);
1001 ender = toCTRL(ender);
1003 case '0': case '1': case '2': case '3':case '4':
1004 case '5': case '6': case '7': case '8':case '9':
1006 (isDIGIT(p[1]) && atoi(p) >= regnpar) ) {
1007 ender = scan_oct(p, 3, &numlen);
1017 FAIL("trailing \\ in regexp");
1025 if (regflags & PMf_EXTENDED) {
1026 while (p < regxend && *p != '\n') p++;
1029 case ' ': case '\t': case '\n': case '\r': case '\f': case '\v':
1030 if (regflags & PMf_EXTENDED) {
1040 if (ISMULT2(p)) { /* Back off on ?+*. */
1055 FAIL("internal disaster in regexp");
1060 if (regcode != ®dummy)
1061 *OPERAND(ret) = len;
1075 if (opnd == ®dummy)
1078 opnd[1 + (c >> 3)] |= (1 << (c & 7));
1084 register char *opnd;
1086 register I32 lastclass = 1234;
1087 register I32 range = 0;
1092 ret = regnode(ANYOF);
1094 for (class = 0; class < 33; class++)
1096 if (*regparse == '^') { /* Complement of range. */
1099 if (opnd != ®dummy)
1100 *opnd |= ANYOF_INVERT;
1102 if (opnd != ®dummy) {
1103 if (regflags & PMf_FOLD)
1104 *opnd |= ANYOF_FOLD;
1105 if (regflags & PMf_LOCALE)
1106 *opnd |= ANYOF_LOCALE;
1108 if (*regparse == ']' || *regparse == '-')
1109 goto skipcond; /* allow 1st char to be ] or - */
1110 while (regparse < regxend && *regparse != ']') {
1112 class = UCHARAT(regparse++);
1113 if (class == '\\') {
1114 class = UCHARAT(regparse++);
1117 if (regflags & PMf_LOCALE) {
1118 if (opnd != ®dummy)
1119 *opnd |= ANYOF_ALNUML;
1122 for (class = 0; class < 256; class++)
1124 regset(opnd, class);
1129 if (regflags & PMf_LOCALE) {
1130 if (opnd != ®dummy)
1131 *opnd |= ANYOF_NALNUML;
1134 for (class = 0; class < 256; class++)
1135 if (!isALNUM(class))
1136 regset(opnd, class);
1141 if (regflags & PMf_LOCALE) {
1142 if (opnd != ®dummy)
1143 *opnd |= ANYOF_SPACEL;
1146 for (class = 0; class < 256; class++)
1148 regset(opnd, class);
1153 if (regflags & PMf_LOCALE) {
1154 if (opnd != ®dummy)
1155 *opnd |= ANYOF_NSPACEL;
1158 for (class = 0; class < 256; class++)
1159 if (!isSPACE(class))
1160 regset(opnd, class);
1165 for (class = '0'; class <= '9'; class++)
1166 regset(opnd, class);
1170 for (class = 0; class < '0'; class++)
1171 regset(opnd, class);
1172 for (class = '9' + 1; class < 256; class++)
1173 regset(opnd, class);
1198 class = scan_hex(regparse, 2, &numlen);
1202 class = UCHARAT(regparse++);
1203 class = toCTRL(class);
1205 case '0': case '1': case '2': case '3': case '4':
1206 case '5': case '6': case '7': case '8': case '9':
1207 class = scan_oct(--regparse, 3, &numlen);
1213 if (lastclass > class)
1214 FAIL("invalid [] range in regexp");
1219 if (*regparse == '-' && regparse+1 < regxend &&
1220 regparse[1] != ']') {
1223 continue; /* do it next time */
1226 for ( ; lastclass <= class; lastclass++)
1227 regset(opnd, lastclass);
1230 if (*regparse != ']')
1231 FAIL("unmatched [] in regexp");
1239 char* retval = regparse++;
1242 if (*regparse == '(' && regparse[1] == '?' &&
1243 regparse[2] == '#') {
1244 while (*regparse && *regparse != ')')
1249 if (regflags & PMf_EXTENDED) {
1250 if (isSPACE(*regparse)) {
1254 else if (*regparse == '#') {
1255 while (*regparse && *regparse != '\n')
1266 - regnode - emit a node
1268 #ifdef CAN_PROTOTYPE
1269 static char * /* Location. */
1272 static char * /* Location. */
1281 if (ret == ®dummy) {
1292 if (!((long)ret & 1))
1298 *ptr++ = '\0'; /* Null "next" pointer. */
1306 - reganode - emit a node with an argument
1308 #ifdef CAN_PROTOTYPE
1309 static char * /* Location. */
1310 reganode(char op, unsigned short arg)
1312 static char * /* Location. */
1322 if (ret == ®dummy) {
1333 if (!((long)ret & 1))
1339 *ptr++ = '\0'; /* Null "next" pointer. */
1342 *(unsigned short *)(ret+3) = arg;
1344 ret[3] = arg >> 8; ret[4] = arg & 0377;
1353 - regc - emit (if appropriate) a byte of code
1355 #ifdef CAN_PROTOTYPE
1364 if (regcode != ®dummy)
1371 - reginsert - insert an operator in front of already-emitted operand
1373 * Means relocating the operand.
1375 #ifdef CAN_PROTOTYPE
1377 reginsert(char op, char *opnd)
1387 register char *place;
1388 register int offset = (regkind[(U8)op] == CURLY ? 4 : 0);
1390 if (regcode == ®dummy) {
1392 regsize += 4 + offset;
1394 regsize += 3 + offset;
1401 regcode += 4 + offset;
1403 regcode += 3 + offset;
1409 place = opnd; /* Op node, where operand used to be. */
1413 while (offset-- > 0)
1421 - regtail - set the next-pointer at the end of a node chain
1428 register char *scan;
1429 register char *temp;
1430 register I32 offset;
1435 /* Find last node. */
1438 temp = regnext(scan);
1445 offset = val - scan;
1447 *(short*)(scan+1) = offset;
1452 if (OP(scan) == BACK)
1453 offset = scan - val;
1455 offset = val - scan;
1456 *(scan+1) = (offset>>8)&0377;
1457 *(scan+2) = offset&0377;
1462 - regoptail - regtail on operand of first argument; nop if operandless
1469 /* "Operandless" and "op != BRANCH" are synonymous in practice. */
1470 if (p == NULL || p == ®dummy || regkind[(U8)OP(p)] != BRANCH)
1472 regtail(NEXTOPER(p), val);
1476 - regcurly - a little FSA that accepts {\d+,?\d*}
1500 - regdump - dump a regexp onto Perl_debug_log in vaguely comprehensible form
1507 register char op = EXACT; /* Arbitrary non-END op. */
1508 register char *next;
1512 while (op != END) { /* While that wasn't END last time... */
1518 PerlIO_printf(Perl_debug_log, "%2d%s", s-r->program, regprop(s)); /* Where, what. */
1520 s += regarglen[(U8)op];
1521 if (next == NULL) /* Next ptr. */
1522 PerlIO_printf(Perl_debug_log, "(0)");
1524 PerlIO_printf(Perl_debug_log, "(%d)", (s-r->program)+(next-s));
1529 if (regkind[(U8)op] == EXACT) {
1530 /* Literal string, where present. */
1532 (void)PerlIO_putc(Perl_debug_log, ' ');
1533 (void)PerlIO_putc(Perl_debug_log, '<');
1534 while (*s != '\0') {
1535 (void)PerlIO_putc(Perl_debug_log,*s);
1538 (void)PerlIO_putc(Perl_debug_log, '>');
1541 (void)PerlIO_putc(Perl_debug_log, '\n');
1544 /* Header fields of interest. */
1546 PerlIO_printf(Perl_debug_log, "start `%s' ", SvPVX(r->regstart));
1548 PerlIO_printf(Perl_debug_log, "stclass `%s' ", regprop(r->regstclass));
1549 if (r->reganch & ROPT_ANCH) {
1550 PerlIO_printf(Perl_debug_log, "anchored");
1551 if (r->reganch & ROPT_ANCH_BOL)
1552 PerlIO_printf(Perl_debug_log, "(BOL)");
1553 if (r->reganch & ROPT_ANCH_GPOS)
1554 PerlIO_printf(Perl_debug_log, "(GPOS)");
1555 PerlIO_putc(Perl_debug_log, ' ');
1557 if (r->reganch & ROPT_SKIP)
1558 PerlIO_printf(Perl_debug_log, "plus ");
1559 if (r->reganch & ROPT_IMPLICIT)
1560 PerlIO_printf(Perl_debug_log, "implicit ");
1561 if (r->regmust != NULL)
1562 PerlIO_printf(Perl_debug_log, "must have \"%s\" back %ld ", SvPVX(r->regmust),
1564 PerlIO_printf(Perl_debug_log, "minlen %ld ", (long) r->minlen);
1565 PerlIO_printf(Perl_debug_log, "\n");
1569 - regprop - printable representation of opcode
1575 register char *p = 0;
1577 (void) strcpy(buf, ":");
1641 (void)sprintf(buf+strlen(buf), "CURLY {%d,%d}", ARG1(op),ARG2(op));
1645 (void)sprintf(buf+strlen(buf), "CURLYX {%d,%d}", ARG1(op),ARG2(op));
1649 (void)sprintf(buf+strlen(buf), "REF%d", ARG1(op));
1653 (void)sprintf(buf+strlen(buf), "OPEN%d", ARG1(op));
1657 (void)sprintf(buf+strlen(buf), "CLOSE%d", ARG1(op));
1715 FAIL("corrupted regexp opcode");
1718 (void) strcat(buf, p);
1721 #endif /* DEBUGGING */
1730 Safefree(r->precomp);
1731 r->precomp = Nullch;
1734 Safefree(r->subbase);
1735 r->subbase = Nullch;
1738 SvREFCNT_dec(r->regmust);
1739 r->regmust = Nullsv;
1742 SvREFCNT_dec(r->regstart);
1743 r->regstart = Nullsv;
1745 Safefree(r->startp);