From: Dave Mitchell Date: Fri, 24 Mar 2006 23:05:11 +0000 (+0000) Subject: make S_regmatch() iterative rather than recursive. X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=95b244405438253236d34c3edcbd0892a86c2dd1;p=p5sagit%2Fp5-mst-13.2.git make S_regmatch() iterative rather than recursive. Goodbye stack-bustng regexes! p4raw-id: //depot/perl@27598 --- diff --git a/regexec.c b/regexec.c index 2190878..79254eb 100644 --- a/regexec.c +++ b/regexec.c @@ -296,7 +296,7 @@ typedef struct re_cc_state #define regcpblow(cp) LEAVE_SCOPE(cp) /* Ignores regcppush()ed data. */ -#define TRYPAREN(paren, n, input) { \ +#define TRYPAREN(paren, n, input, where) { \ if (paren) { \ if (n) { \ PL_regstartp[paren] = HOPc(input, -1) - PL_bostr; \ @@ -305,7 +305,8 @@ typedef struct re_cc_state else \ PL_regendp[paren] = -1; \ } \ - if (regmatch(next)) \ + REGMATCH(next, where); \ + if (result) \ sayYES; \ if (paren && n) \ PL_regendp[paren] = -1; \ @@ -1646,8 +1647,6 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char * PERL_UNUSED_ARG(data); RX_MATCH_UTF8_set(prog,do_utf8); - PL_regcc = 0; - cache_re(prog); #ifdef DEBUGGING PL_regnarrate = DEBUG_r_TEST; @@ -2313,6 +2312,69 @@ typedef union re_unwind_t { #define TRIE_INITAL_ACCEPT_BUFFLEN 4; +/* simulate a recursive call to regmatch */ + +#define REGMATCH(ns, where) \ + new_scan = (ns); \ + resume_state = resume_##where; \ + goto start_recurse; \ + resume_point_##where: + +typedef enum { + resume_TRIE1, + resume_TRIE2, + resume_CURLYX, + resume_WHILEM1, + resume_WHILEM2, + resume_WHILEM3, + resume_WHILEM4, + resume_WHILEM5, + resume_WHILEM6, + resume_CURLYM1, + resume_CURLYM2, + resume_CURLYM3, + resume_CURLYM4, + resume_IFMATCH, + resume_PLUS1, + resume_PLUS2, + resume_PLUS3, + resume_PLUS4, + resume_END +} resume_states; + + +struct regmatch_state { + struct regmatch_state *prev_state; + resume_states resume_state; + regnode *scan; + regnode *next; + bool minmod; + bool sw; + int logical; + I32 unwind; + CURCUR *cc; + char *locinput; + + I32 n; + I32 ln; + I32 c1, c2, paren; + CHECKPOINT cp, lastcp; + CURCUR *oldcc; + char *lastloc; + I32 cache_offset, cache_bit; + I32 curlym_l; + I32 matches; + I32 maxwanted; + char *e; + char *old; + int count; + re_cc_state *cur_call_cc; + regexp *end_re; + reg_trie_accepted *accept_buff; + U32 accepted; + + re_cc_state *reg_call_cc; /* saved value of PL_reg_call_cc */ +}; /* - regmatch - main matching routine @@ -2327,44 +2389,154 @@ typedef union re_unwind_t { /* [lwall] I've hoisted the register declarations to the outer block in order to * maybe save a little bit of pushing and popping on the stack. It also takes * advantage of machines that use a register save mask on subroutine entry. + * + * This function used to be heavily recursive, but since this had the + * effect of blowing the CPU stack on complex regexes, it has been + * restructured to be iterative, and to save state onto the heap rather + * than the stack. Essentially whereever regmatch() used to be called, it + * pushes the current state, notes where to return, then jumps back into + * the main loop. + * + * Originally the structure of this function used to look something like + + S_regmatch() { + int a = 1, b = 2; + ... + while (scan != NULL) { + ... + switch (OP(scan)) { + case FOO: { + int local = 3; + ... + if (regmatch(...)) // recurse + goto yes; + } + ... + } + } + yes: + return 1; + } + + * Now it looks something like this: + + struct regmatch_state { + int a, b, local; + int resume_state; + }; + + S_regmatch() { + int a = 1, b = 2; + int local; + ... + while (scan != NULL) { + ... + switch (OP(scan)) { + case FOO: { + local = 3; + ... + resume_state = resume_FOO; + new_scan = ...; + goto start_recurse; + resume_point_FOO: + + if (result) // recurse + goto yes; + } + ... + } + start_recurse: + ...push a, b, local onto the heap + a = 1; b = 2; + scan = new_scan; + } + yes: + result = 1; + if (states pushed on heap) { + ... restore a, b, local from heap + switch (resume_state) { + case resume_FOO: + goto resume_point_FOO; + ... + } + } + return result + } + + * WARNING: this means that any line in this function that contains a + * REGMATCH() or TRYPAREN() is actually simulating a recursive call to + * regmatch() using gotos instead. Thus the values of any local variables + * not saved in the regmatch_state structure will have been lost when + * execution resumes on the next line . */ + + STATIC I32 /* 0 failure, 1 success */ S_regmatch(pTHX_ regnode *prog) { dVAR; + register const bool do_utf8 = PL_reg_match_utf8; + const U32 uniflags = ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY; + + /************************************************************ + * the following variabes are saved and restored on each fake + * recursive call to regmatch: + * + * The first ones contain state that needs to be maintained + * across the main while loop: */ + + struct regmatch_state *prev_state = NULL; /* stack of pushed states */ + resume_states resume_state; /* where to jump to on return */ register regnode *scan; /* Current node. */ regnode *next; /* Next node. */ - regnode *inner; /* Next node in internal branch. */ - register I32 nextchr; /* renamed nextchr - nextchar colides with - function of same name */ - register I32 n; /* no or next */ - register I32 ln = 0; /* len or last */ - register char *s = NULL; /* operand or save */ + bool minmod = 0; /* the next {n.m} is a {n,m}? */ + bool sw = 0; /* the condition value in (?(cond)a|b) */ + int logical = 0; + I32 unwind = 0; /* savestack index of current unwind block */ + CURCUR *cc = NULL; /* current innermost curly struct */ register char *locinput = PL_reginput; - register I32 c1 = 0, c2 = 0, paren; /* case fold search, parenth */ - int minmod = 0, sw = 0, logical = 0; - I32 unwind = 0; -#if 0 - I32 firstcp = PL_savestack_ix; -#endif - register const bool do_utf8 = PL_reg_match_utf8; -#ifdef DEBUGGING - SV * const dsv0 = PERL_DEBUG_PAD_ZERO(0); - SV * const dsv1 = PERL_DEBUG_PAD_ZERO(1); - SV * const dsv2 = PERL_DEBUG_PAD_ZERO(2); + /* while the rest of these are local to an individual branch, and + * have only been hoisted into this outer scope to allow for saving and + * restoration - thus they can be safely reused in other branches. + * Note that they are only initialized here to silence compiler + * warnings :-( */ + register I32 n = 0; /* no or next */ + register I32 ln = 0; /* len or last */ + register I32 c1 = 0, c2 = 0, paren = 0; /* case fold search, parenth */ + CHECKPOINT cp = 0; /* remember current savestack indexes */ + CHECKPOINT lastcp = 0; + CURCUR *oldcc = NULL; /* tmp copy of cc */ + char *lastloc = NULL; /* Detection of 0-len. */ + I32 cache_offset = 0; + I32 cache_bit = 0; + I32 curlym_l = 0; + I32 matches = 0; + I32 maxwanted = 0; + char *e = NULL; + char *old = NULL; + int count = 0; + re_cc_state *cur_call_cc = NULL; + regexp *end_re = NULL; + reg_trie_accepted *accept_buff = NULL; + U32 accepted = 0; /* how many accepting states we have seen */ + + /************************************************************ + * these variables are NOT saved: */ + + register I32 nextchr; /* is always set to UCHARAT(locinput) */ + regnode *new_scan; /* node to begin exedcution at when recursing */ + bool result; /* return value of S_regmatch */ + + regnode *inner; /* Next node in internal branch. */ + +#ifdef DEBUGGING SV *re_debug_flags = NULL; -#endif - U32 uniflags = ckWARN(WARN_UTF8) ? 0 : UTF8_ALLOW_ANY; - GET_RE_DEBUG_FLAGS; - -#ifdef DEBUGGING PL_regindent++; #endif - /* Note that nextchr is a byte even in UTF */ nextchr = UCHARAT(locinput); scan = prog; @@ -2401,17 +2573,18 @@ S_regmatch(pTHX_ regnode *prog) { const char * const s0 = do_utf8 && OP(scan) != CANY ? - pv_uni_display(dsv0, (U8*)(locinput - pref_len), + pv_uni_display(PERL_DEBUG_PAD(0), (U8*)(locinput - pref_len), pref0_len, 60, UNI_DISPLAY_REGEX) : locinput - pref_len; const int len0 = do_utf8 ? strlen(s0) : pref0_len; const char * const s1 = do_utf8 && OP(scan) != CANY ? - pv_uni_display(dsv1, (U8*)(locinput - pref_len + pref0_len), + pv_uni_display(PERL_DEBUG_PAD(1), + (U8*)(locinput - pref_len + pref0_len), pref_len - pref0_len, 60, UNI_DISPLAY_REGEX) : locinput - pref_len + pref0_len; const int len1 = do_utf8 ? strlen(s1) : pref_len - pref0_len; const char * const s2 = do_utf8 && OP(scan) != CANY ? - pv_uni_display(dsv2, (U8*)locinput, + pv_uni_display(PERL_DEBUG_PAD(2), (U8*)locinput, PL_regeol - locinput, 60, UNI_DISPLAY_REGEX) : locinput; const int len2 = do_utf8 ? strlen(s2) : l; @@ -2530,18 +2703,16 @@ S_regmatch(pTHX_ regnode *prog) STRLEN foldlen = 0; U8 *uscan = (U8*)NULL; STRLEN bufflen=0; + SV *sv_accept_buff = NULL; const enum { trie_plain, trie_utf8, trie_uft8_fold } trie_type = do_utf8 ? (OP(scan) == TRIE ? trie_utf8 : trie_uft8_fold) : trie_plain; - int gotit = 0; - /* accepting states we have traversed */ - SV *sv_accept_buff = NULL; - reg_trie_accepted *accept_buff = NULL; reg_trie_data *trie; /* what trie are we using right now */ - U32 accepted = 0; /* how many accepting states we have seen */ + accepted = 0; /* how many accepting states we have seen */ + result = 0; trie = (reg_trie_data*)PL_regdata->data[ ARG( scan ) ]; while ( state && uc <= (U8*)PL_regeol ) { @@ -2679,14 +2850,15 @@ S_regmatch(pTHX_ regnode *prog) as we wont be using accept_buff again. */ FREETMPS; LEAVE; - gotit = regmatch( scan + NEXT_OFF( scan ) ); + REGMATCH(scan + NEXT_OFF(scan), TRIE1); + /*** all unsaved local vars undefined at this point */ } else { DEBUG_EXECUTE_r( PerlIO_printf( Perl_debug_log,"%*s %sgot %"IVdf" possible matches%s\n", REPORT_CODE_OFF + PL_regindent * 2, "", PL_colors[4], (IV)accepted, PL_colors[5] ); ); - while ( !gotit && accepted-- ) { + while ( !result && accepted-- ) { U32 best = 0; U32 cur; for( cur = 1 ; cur <= accepted ; cur++ ) { @@ -2723,22 +2895,23 @@ S_regmatch(pTHX_ regnode *prog) all until I can be sure. */ SAVETMPS; - gotit = regmatch( scan + NEXT_OFF( scan ) ) ; + REGMATCH(scan + NEXT_OFF(scan), TRIE2); + /*** all unsaved local vars undefined at this point */ FREETMPS; } FREETMPS; LEAVE; } - if ( gotit ) { + if (result) { sayYES; } else { sayNO; } } /* unreached codepoint */ - case EXACT: - s = STRING(scan); + case EXACT: { + char *s = STRING(scan); ln = STR_LEN(scan); if (do_utf8 != UTF) { /* The target and the pattern have differing utf8ness. */ @@ -2788,11 +2961,12 @@ S_regmatch(pTHX_ regnode *prog) locinput += ln; nextchr = UCHARAT(locinput); break; + } case EXACTFL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ - case EXACTF: - s = STRING(scan); + case EXACTF: { + char *s = STRING(scan); ln = STR_LEN(scan); if (do_utf8 || UTF) { @@ -2836,6 +3010,7 @@ S_regmatch(pTHX_ regnode *prog) locinput += ln; nextchr = UCHARAT(locinput); break; + } case ANYOF: if (do_utf8) { STRLEN inclasslen = PL_regeol - locinput; @@ -3078,7 +3253,8 @@ S_regmatch(pTHX_ regnode *prog) PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case REF: - case REFF: + case REFF: { + char *s; n = ARG(scan); /* which paren pair */ ln = PL_regstartp[n]; PL_reg_leftiter = PL_reg_maxiter; /* Void cache */ @@ -3135,6 +3311,7 @@ S_regmatch(pTHX_ regnode *prog) locinput += ln; nextchr = UCHARAT(locinput); break; + } case NOTHING: case TAIL: @@ -3176,7 +3353,6 @@ S_regmatch(pTHX_ regnode *prog) regexp *re; MAGIC *mg = NULL; re_cc_state state; - CHECKPOINT cp, lastcp; int toggleutf; register SV *sv; @@ -3223,10 +3399,10 @@ S_regmatch(pTHX_ regnode *prog) ); state.node = next; state.prev = PL_reg_call_cc; - state.cc = PL_regcc; + state.cc = cc; state.re = PL_reg_re; - PL_regcc = 0; + cc = 0; cp = regcppush(0); /* Save *all* the positions. */ REGCP_SET(lastcp); @@ -3243,6 +3419,7 @@ S_regmatch(pTHX_ regnode *prog) /* XXXX This is too dramatic a measure... */ PL_reg_maxiter = 0; + /* XXX the only recursion left in regmatch() */ if (regmatch(re->program + 1)) { /* Even though we succeeded, we need to restore global variables, since we may be wrapped inside @@ -3250,7 +3427,7 @@ S_regmatch(pTHX_ regnode *prog) /* XXXX Do this only if SUSPENDed? */ PL_reg_call_cc = state.prev; - PL_regcc = state.cc; + cc = state.cc; PL_reg_re = state.re; cache_re(PL_reg_re); if (toggleutf) PL_reg_flags ^= RF_utf8; @@ -3267,7 +3444,7 @@ S_regmatch(pTHX_ regnode *prog) REGCP_UNWIND(lastcp); regcppop(); PL_reg_call_cc = state.prev; - PL_regcc = state.cc; + cc = state.cc; PL_reg_re = state.re; cache_re(PL_reg_re); if (toggleutf) PL_reg_flags ^= RF_utf8; @@ -3319,15 +3496,15 @@ S_regmatch(pTHX_ regnode *prog) logical = scan->flags; break; /******************************************************************* - PL_regcc contains infoblock about the innermost (...)* loop, and + cc contains infoblock about the innermost (...)* loop, and a pointer to the next outer infoblock. Here is how Y(A)*Z is processed (if it is compiled into CURLYX/WHILEM): - 1) After matching X, regnode for CURLYX is processed; + 1) After matching Y, regnode for CURLYX is processed; - 2) This regnode creates infoblock on the stack, and calls - regmatch() recursively with the starting point at WHILEM node; + 2) This regnode mallocs an infoblock, and calls regmatch() recursively + with the starting point at WHILEM node; 3) Each hit of WHILEM node tries to match A and Z (in the order depending on the current iteration, min/max of {min,max} and @@ -3337,9 +3514,9 @@ S_regmatch(pTHX_ regnode *prog) 4) After A matches, the same WHILEM node is hit again. - 5) Each time WHILEM is hit, PL_regcc is the infoblock created by CURLYX + 5) Each time WHILEM is hit, cc is the infoblock created by CURLYX of the same pair. Thus when WHILEM tries to match Z, it temporarily - resets PL_regcc, since this Y(A)*Z can be a part of some other loop: + resets cc, since this Y(A)*Z can be a part of some other loop: as in (Y(A)*Z)*. If Z matches, the automaton will hit the WHILEM node of the external loop. @@ -3347,7 +3524,7 @@ S_regmatch(pTHX_ regnode *prog) and whatever it mentions via ->next, and additional attached trees corresponding to temporarily unset infoblocks as in "5" above. - In the following picture infoblocks for outer loop of + In the following picture, infoblocks for outer loop of (Y(A)*?Z)*?T are denoted O, for inner I. NULL starting block is denoted by x. The matched string is YAAZYAZT. Temporarily postponed infoblocks are drawn below the "reset" infoblock. @@ -3393,33 +3570,40 @@ S_regmatch(pTHX_ regnode *prog) O I,I *******************************************************************/ + case CURLYX: { - CURCUR cc; - CHECKPOINT cp = PL_savestack_ix; /* No need to save/restore up to this paren */ I32 parenfloor = scan->flags; + { + CURCUR *newcc; + Newx(newcc, 1, CURCUR); + oldcc = cc; + newcc->oldcc = cc; + cc = newcc; + } + cp = PL_savestack_ix; if (OP(PREVOPER(next)) == NOTHING) /* LONGJMP */ next += ARG(next); - cc.oldcc = PL_regcc; - PL_regcc = &cc; /* XXXX Probably it is better to teach regpush to support parenfloor > PL_regsize... */ if (parenfloor > (I32)*PL_reglastparen) parenfloor = *PL_reglastparen; /* Pessimization... */ - cc.parenfloor = parenfloor; - cc.cur = -1; - cc.min = ARG1(scan); - cc.max = ARG2(scan); - cc.scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS; - cc.next = next; - cc.minmod = minmod; - cc.lastloc = 0; + cc->parenfloor = parenfloor; + cc->cur = -1; + cc->min = ARG1(scan); + cc->max = ARG2(scan); + cc->scan = NEXTOPER(scan) + EXTRA_STEP_2ARGS; + cc->next = next; + cc->minmod = minmod; + cc->lastloc = 0; PL_reginput = locinput; - n = regmatch(PREVOPER(next)); /* start on the WHILEM */ + REGMATCH(PREVOPER(next), CURLYX); /* start on the WHILEM */ + /*** all unsaved local vars undefined at this point */ regcpblow(cp); - PL_regcc = cc.oldcc; - saySAME(n); + Safefree(cc); + cc = oldcc; + saySAME(result); } /* NOTREACHED */ case WHILEM: { @@ -3432,10 +3616,9 @@ S_regmatch(pTHX_ regnode *prog) * that we can try again after backing off. */ - CHECKPOINT cp, lastcp; - CURCUR* cc = PL_regcc; - char * const lastloc = cc->lastloc; /* Detection of 0-len. */ - I32 cache_offset = 0, cache_bit = 0; + lastloc = cc->lastloc; /* Detection of 0-len. */ + cache_offset = 0; + cache_bit = 0; n = cc->cur + 1; /* how many we know we matched */ PL_reginput = locinput; @@ -3451,19 +3634,22 @@ S_regmatch(pTHX_ regnode *prog) /* If degenerate scan matches "", assume scan done. */ if (locinput == cc->lastloc && n >= cc->min) { - PL_regcc = cc->oldcc; - if (PL_regcc) - ln = PL_regcc->cur; + oldcc = cc; + cc = cc->oldcc; + if (cc) + ln = cc->cur; DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log, "%*s empty match detected, try continuation...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); - if (regmatch(cc->next)) + REGMATCH(oldcc->next, WHILEM1); + /*** all unsaved local vars undefined at this point */ + cc = oldcc; + if (result) sayYES; - if (PL_regcc) - PL_regcc->cur = ln; - PL_regcc = cc; + if (cc->oldcc) + cc->oldcc->cur = ln; sayNO; } @@ -3472,7 +3658,9 @@ S_regmatch(pTHX_ regnode *prog) if (n < cc->min) { cc->cur = n; cc->lastloc = locinput; - if (regmatch(cc->scan)) + REGMATCH(cc->scan, WHILEM2); + /*** all unsaved local vars undefined at this point */ + if (result) sayYES; cc->cur = n - 1; cc->lastloc = lastloc; @@ -3533,20 +3721,23 @@ S_regmatch(pTHX_ regnode *prog) /* Prefer next over scan for minimal matching. */ if (cc->minmod) { - PL_regcc = cc->oldcc; - if (PL_regcc) - ln = PL_regcc->cur; - cp = regcppush(cc->parenfloor); + oldcc = cc; + cc = cc->oldcc; + if (cc) + ln = cc->cur; + cp = regcppush(oldcc->parenfloor); REGCP_SET(lastcp); - if (regmatch(cc->next)) { + REGMATCH(oldcc->next, WHILEM3); + /*** all unsaved local vars undefined at this point */ + cc = oldcc; + if (result) { regcpblow(cp); CACHEsayYES; /* All done. */ } REGCP_UNWIND(lastcp); regcppop(); - if (PL_regcc) - PL_regcc->cur = ln; - PL_regcc = cc; + if (cc->oldcc) + cc->oldcc->cur = ln; if (n >= cc->max) { /* Maximum greed exceeded? */ if (ckWARN(WARN_REGEXP) && n >= REG_INFTY @@ -3570,7 +3761,9 @@ S_regmatch(pTHX_ regnode *prog) cc->lastloc = locinput; cp = regcppush(cc->parenfloor); REGCP_SET(lastcp); - if (regmatch(cc->scan)) { + REGMATCH(cc->scan, WHILEM4); + /*** all unsaved local vars undefined at this point */ + if (result) { regcpblow(cp); CACHEsayYES; } @@ -3588,7 +3781,9 @@ S_regmatch(pTHX_ regnode *prog) cc->cur = n; cc->lastloc = locinput; REGCP_SET(lastcp); - if (regmatch(cc->scan)) { + REGMATCH(cc->scan, WHILEM5); + /*** all unsaved local vars undefined at this point */ + if (result) { regcpblow(cp); CACHEsayYES; } @@ -3610,14 +3805,17 @@ S_regmatch(pTHX_ regnode *prog) } /* Failed deeper matches of scan, so see if this one works. */ - PL_regcc = cc->oldcc; - if (PL_regcc) - ln = PL_regcc->cur; - if (regmatch(cc->next)) + oldcc = cc; + cc = cc->oldcc; + if (cc) + ln = cc->cur; + REGMATCH(oldcc->next, WHILEM6); + /*** all unsaved local vars undefined at this point */ + cc = oldcc; + if (result) CACHEsayYES; - if (PL_regcc) - PL_regcc->cur = ln; - PL_regcc = cc; + if (cc->oldcc) + cc->oldcc->cur = ln; cc->cur = n - 1; cc->lastloc = lastloc; CACHEsayNO; @@ -3667,10 +3865,7 @@ S_regmatch(pTHX_ regnode *prog) break; case CURLYM: { - I32 l = 0; - I32 matches = 0; - CHECKPOINT lastcp; - I32 maxwanted; + curlym_l = matches = 0; /* We suppose that the next guy does not need backtracking: in particular, it is of constant non-zero length, @@ -3691,21 +3886,23 @@ S_regmatch(pTHX_ regnode *prog) maxwanted = minmod ? ln : n; if (maxwanted) { while (PL_reginput < PL_regeol && matches < maxwanted) { - if (!regmatch(scan)) + REGMATCH(scan, CURLYM1); + /*** all unsaved local vars undefined at this point */ + if (!result) break; - /* on first match, determine length, l */ + /* on first match, determine length, curlym_l */ if (!matches++) { if (PL_reg_match_utf8) { char *s = locinput; while (s < PL_reginput) { - l++; + curlym_l++; s += UTF8SKIP(s); } } else { - l = PL_reginput - locinput; + curlym_l = PL_reginput - locinput; } - if (l == 0) { + if (curlym_l == 0) { matches = maxwanted; break; } @@ -3753,19 +3950,23 @@ S_regmatch(pTHX_ regnode *prog) if (paren) { if (ln) { PL_regstartp[paren] = - HOPc(PL_reginput, -l) - PL_bostr; + HOPc(PL_reginput, -curlym_l) - PL_bostr; PL_regendp[paren] = PL_reginput - PL_bostr; } else PL_regendp[paren] = -1; } - if (regmatch(next)) + REGMATCH(next, CURLYM2); + /*** all unsaved local vars undefined at this point */ + if (result) sayYES; REGCP_UNWIND(lastcp); } /* Couldn't or didn't -- move forward. */ PL_reginput = locinput; - if (regmatch(scan)) { + REGMATCH(scan, CURLYM3); + /*** all unsaved local vars undefined at this point */ + if (result) { ln++; locinput = PL_reginput; } @@ -3776,9 +3977,9 @@ S_regmatch(pTHX_ regnode *prog) else { DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log, - "%*s matched %"IVdf" times, len=%"IVdf"...\n", - (int)(REPORT_CODE_OFF+PL_regindent*2), "", - (IV) matches, (IV)l) + "%*s matched %"IVdf" times, len=%"IVdf"...\n", + (int)(REPORT_CODE_OFF+PL_regindent*2), "", + (IV) matches, (IV)curlym_l) ); if (matches >= ln) { if (HAS_TEXT(next) || JUMPABLE(next)) { @@ -3821,19 +4022,22 @@ S_regmatch(pTHX_ regnode *prog) ); if (paren) { if (matches) { - PL_regstartp[paren] = HOPc(PL_reginput, -l) - PL_bostr; + PL_regstartp[paren] + = HOPc(PL_reginput, -curlym_l) - PL_bostr; PL_regendp[paren] = PL_reginput - PL_bostr; } else PL_regendp[paren] = -1; } - if (regmatch(next)) + REGMATCH(next, CURLYM4); + /*** all unsaved local vars undefined at this point */ + if (result) sayYES; REGCP_UNWIND(lastcp); } /* Couldn't or didn't -- back up. */ matches--; - locinput = HOPc(locinput, -l); + locinput = HOPc(locinput, -curlym_l); PL_reginput = locinput; } } @@ -3927,16 +4131,14 @@ S_regmatch(pTHX_ regnode *prog) assume_ok_easy: PL_reginput = locinput; if (minmod) { - CHECKPOINT lastcp; minmod = 0; if (ln && regrepeat(scan, ln) < ln) sayNO; locinput = PL_reginput; REGCP_SET(lastcp); if (c1 != -1000) { - char *e; /* Should not check after this */ - char *old = locinput; - int count = 0; + old = locinput; + count = 0; if (n == REG_INFTY) { e = PL_regeol - 1; @@ -4006,7 +4208,8 @@ S_regmatch(pTHX_ regnode *prog) sayNO; } /* PL_reginput == locinput now */ - TRYPAREN(paren, ln, locinput); + TRYPAREN(paren, ln, locinput, PLUS1); + /*** all unsaved local vars undefined at this point */ PL_reginput = locinput; /* Could be reset... */ REGCP_UNWIND(lastcp); /* Couldn't or didn't -- move forward. */ @@ -4031,14 +4234,16 @@ S_regmatch(pTHX_ regnode *prog) /* If it could work, try it. */ if (c == (UV)c1 || c == (UV)c2) { - TRYPAREN(paren, ln, PL_reginput); + TRYPAREN(paren, ln, PL_reginput, PLUS2); + /*** all unsaved local vars undefined at this point */ REGCP_UNWIND(lastcp); } } /* If it could work, try it. */ else if (c1 == -1000) { - TRYPAREN(paren, ln, PL_reginput); + TRYPAREN(paren, ln, PL_reginput, PLUS3); + /*** all unsaved local vars undefined at this point */ REGCP_UNWIND(lastcp); } /* Couldn't or didn't -- move forward. */ @@ -4052,7 +4257,6 @@ S_regmatch(pTHX_ regnode *prog) } } else { - CHECKPOINT lastcp; n = regrepeat(scan, n); locinput = PL_reginput; if (ln < n && PL_regkind[(U8)OP(next)] == EOL && @@ -4081,7 +4285,8 @@ S_regmatch(pTHX_ regnode *prog) /* If it could work, try it. */ if (c1 == -1000 || c == (UV)c1 || c == (UV)c2) { - TRYPAREN(paren, n, PL_reginput); + TRYPAREN(paren, n, PL_reginput, PLUS4); + /*** all unsaved local vars undefined at this point */ REGCP_UNWIND(lastcp); } /* Couldn't or didn't -- back up. */ @@ -4094,29 +4299,31 @@ S_regmatch(pTHX_ regnode *prog) break; case END: if (PL_reg_call_cc) { - re_cc_state *cur_call_cc = PL_reg_call_cc; - CURCUR *cctmp = PL_regcc; - regexp *re = PL_reg_re; - CHECKPOINT lastcp; - I32 tmp; + cur_call_cc = PL_reg_call_cc; + end_re = PL_reg_re; /* Save *all* the positions. */ - const CHECKPOINT cp = regcppush(0); + cp = regcppush(0); REGCP_SET(lastcp); /* Restore parens of the caller. */ - tmp = PL_savestack_ix; - PL_savestack_ix = PL_reg_call_cc->ss; - regcppop(); - PL_savestack_ix = tmp; + { + I32 tmp = PL_savestack_ix; + PL_savestack_ix = PL_reg_call_cc->ss; + regcppop(); + PL_savestack_ix = tmp; + } /* Make position available to the callcc. */ PL_reginput = locinput; cache_re(PL_reg_call_cc->re); - PL_regcc = PL_reg_call_cc->cc; + oldcc = cc; + cc = PL_reg_call_cc->cc; PL_reg_call_cc = PL_reg_call_cc->prev; - if (regmatch(cur_call_cc->node)) { + REGMATCH(cur_call_cc->node, END); + /*** all unsaved local vars undefined at this point */ + if (result) { PL_reg_call_cc = cur_call_cc; regcpblow(cp); sayYES; @@ -4124,9 +4331,9 @@ S_regmatch(pTHX_ regnode *prog) REGCP_UNWIND(lastcp); regcppop(); PL_reg_call_cc = cur_call_cc; - PL_regcc = cctmp; - PL_reg_re = re; - cache_re(re); + cc = oldcc; + PL_reg_re = end_re; + cache_re(end_re); DEBUG_EXECUTE_r( PerlIO_printf(Perl_debug_log, @@ -4156,7 +4363,7 @@ S_regmatch(pTHX_ regnode *prog) case UNLESSM: n = 0; if (scan->flags) { - s = HOPBACKc(locinput, scan->flags); + char *s = HOPBACKc(locinput, scan->flags); if (!s) goto say_yes; PL_reginput = s; @@ -4167,7 +4374,7 @@ S_regmatch(pTHX_ regnode *prog) case IFMATCH: n = 1; if (scan->flags) { - s = HOPBACKc(locinput, scan->flags); + char *s = HOPBACKc(locinput, scan->flags); if (!s) goto say_no; PL_reginput = s; @@ -4176,8 +4383,9 @@ S_regmatch(pTHX_ regnode *prog) PL_reginput = locinput; do_ifmatch: - inner = NEXTOPER(NEXTOPER(scan)); - if (regmatch(inner) != n) { + REGMATCH(NEXTOPER(NEXTOPER(scan)), IFMATCH); + /*** all unsaved local vars undefined at this point */ + if (result != n) { say_no: if (logical) { logical = 0; @@ -4208,8 +4416,68 @@ S_regmatch(pTHX_ regnode *prog) PTR2UV(scan), OP(scan)); Perl_croak(aTHX_ "regexp memory corruption"); } + reenter: scan = next; + continue; + /* NOTREACHED */ + + /* simulate recursively calling regmatch(), but without actually + * recursing - ie save the current state on the heap rather than on + * the stack, then re-enter the loop. This avoids complex regexes + * blowing the processor stack */ + + start_recurse: + { + /* save existing local variables */ + struct regmatch_state *p; + + Newx(p, 1, struct regmatch_state); + p->prev_state = prev_state; + prev_state = p; + p->resume_state = resume_state; + p->scan = scan; + p->next = next; + p->minmod = minmod; + p->sw = sw; + p->logical = logical; + p->unwind = unwind; + p->cc = cc; + p->locinput = locinput; + p->n = n; + p->ln = ln; + p->c1 = c1; + p->c2 = c2; + p->paren = paren; + p->cp = cp; + p->lastcp = lastcp; + p->oldcc = oldcc; + p->lastloc = lastloc; + p->cache_offset = cache_offset; + p->cache_bit = cache_bit; + p->curlym_l = curlym_l; + p->matches = matches; + p->maxwanted = maxwanted; + p->e = e; + p->old = old; + p->count = count; + p->cur_call_cc = cur_call_cc; + p->end_re = end_re; + p->accept_buff = accept_buff; + p->accepted = accepted; + p->reg_call_cc = PL_reg_call_cc; + + scan = new_scan; + locinput = PL_reginput; + nextchr = UCHARAT(locinput); + minmod = 0; + sw = 0; + logical = 0; + unwind = 0; +#ifdef DEBUGGING + PL_regindent++; +#endif + } } /* @@ -4235,11 +4503,8 @@ yes: PL_regindent--; #endif -#if 0 /* Breaks $^R */ - if (unwind) - regcpblow(firstcp); -#endif - return 1; + result = 1; + goto exit_level; no: DEBUG_EXECUTE_r( @@ -4301,7 +4566,92 @@ do_no: #ifdef DEBUGGING PL_regindent--; #endif - return 0; + result = 0; +exit_level: + if (prev_state) { + /* restore previous state and re-enter */ + + struct regmatch_state *p = prev_state; + resume_state = p->resume_state; + scan = p->scan; + next = p->next; + minmod = p->minmod; + sw = p->sw; + logical = p->logical; + unwind = p->unwind; + cc = p->cc; + locinput = p->locinput; + nextchr = UCHARAT(locinput); + n = p->n; + ln = p->ln; + c1 = p->c1; + c2 = p->c2; + paren = p->paren; + cp = p->cp; + lastcp = p->lastcp; + oldcc = p->oldcc; + lastloc = p->lastloc; + cache_offset = p->cache_offset; + cache_bit = p->cache_bit; + curlym_l = p->curlym_l; + matches = p->matches; + maxwanted = p->maxwanted; + e = p->e; + old = p->old; + count = p->count; + cur_call_cc = p->cur_call_cc; + end_re = p->end_re; + accept_buff = p->accept_buff; + accepted = p->accepted; + PL_reg_call_cc = p->reg_call_cc; + prev_state = p->prev_state; + + switch (resume_state) { + case resume_TRIE1: + goto resume_point_TRIE1; + case resume_TRIE2: + goto resume_point_TRIE2; + case resume_CURLYX: + goto resume_point_CURLYX; + case resume_WHILEM1: + goto resume_point_WHILEM1; + case resume_WHILEM2: + goto resume_point_WHILEM2; + case resume_WHILEM3: + goto resume_point_WHILEM3; + case resume_WHILEM4: + goto resume_point_WHILEM4; + case resume_WHILEM5: + goto resume_point_WHILEM5; + case resume_WHILEM6: + goto resume_point_WHILEM6; + case resume_CURLYM1: + goto resume_point_CURLYM1; + case resume_CURLYM2: + goto resume_point_CURLYM2; + case resume_CURLYM3: + goto resume_point_CURLYM3; + case resume_CURLYM4: + goto resume_point_CURLYM4; + case resume_IFMATCH: + goto resume_point_IFMATCH; + case resume_PLUS1: + goto resume_point_PLUS1; + case resume_PLUS2: + goto resume_point_PLUS2; + case resume_PLUS3: + goto resume_point_PLUS3; + case resume_PLUS4: + goto resume_point_PLUS4; + case resume_END: + goto resume_point_END; + default: + Perl_croak(aTHX_ "regexp resume memory corruption"); + } + /* NOTREACHED */ + } + return result; + } /*