/* regexec.c */ /* * "One Ring to rule them all, One Ring to find them..." */ /* NOTE: this is derived from Henry Spencer's regexp code, and should not * confused with the original package (see point 3 below). Thanks, Henry! */ /* Additional note: this code is very heavily munged from Henry's version * in places. In some spots I've traded clarity for efficiency, so don't * blame Henry for some of the lack of readability. */ /* The names of the functions have been changed from regcomp and * regexec to pregcomp and pregexec in order to avoid conflicts * with the POSIX routines of the same names. */ #ifdef PERL_EXT_RE_BUILD /* need to replace pregcomp et al, so enable that */ # ifndef PERL_IN_XSUB_RE # define PERL_IN_XSUB_RE # endif /* need access to debugger hooks */ # ifndef DEBUGGING # define DEBUGGING # endif #endif #ifdef PERL_IN_XSUB_RE /* We *really* need to overwrite these symbols: */ # define Perl_regexec_flags my_regexec # define Perl_regdump my_regdump # define Perl_regprop my_regprop /* *These* symbols are masked to allow static link. */ # define Perl_pregexec my_pregexec #endif /*SUPPRESS 112*/ /* * pregcomp and pregexec -- regsub and regerror are not used in perl * * Copyright (c) 1986 by University of Toronto. * Written by Henry Spencer. Not derived from licensed software. * * Permission is granted to anyone to use this software for any * purpose on any computer system, and to redistribute it freely, * subject to the following restrictions: * * 1. The author is not responsible for the consequences of use of * this software, no matter how awful, even if they arise * from defects in it. * * 2. The origin of this software must not be misrepresented, either * by explicit claim or by omission. * * 3. Altered versions must be plainly marked as such, and must not * be misrepresented as being the original software. * **** Alterations to Henry's code are... **** **** Copyright (c) 1991-1999, Larry Wall **** **** You may distribute under the terms of either the GNU General Public **** License or the Artistic License, as specified in the README file. * * Beware that some of this code is subtly aware of the way operator * precedence is structured in regular expressions. Serious changes in * regular-expression syntax might require a total rethink. */ #include "EXTERN.h" #include "perl.h" #include "regcomp.h" #define RF_tainted 1 /* tainted information used? */ #define RF_warned 2 /* warned about big count? */ #define RF_evaled 4 /* Did an EVAL with setting? */ #define RS_init 1 /* eval environment created */ #define RS_set 2 /* replsv value is set */ #ifndef STATIC #define STATIC static #endif #ifndef PERL_OBJECT typedef I32 CHECKPOINT; /* * Forwards. */ static I32 regmatch _((regnode *prog)); static I32 regrepeat _((regnode *p, I32 max)); static I32 regrepeat_hard _((regnode *p, I32 max, I32 *lp)); static I32 regtry _((regexp *prog, char *startpos)); static bool reginclass _((char *p, I32 c)); static CHECKPOINT regcppush _((I32 parenfloor)); static char * regcppop _((void)); #endif #define REGINCLASS(p,c) (*(p) ? reginclass(p,c) : ANYOF_TEST(p,c)) STATIC CHECKPOINT regcppush(I32 parenfloor) { dTHR; int retval = PL_savestack_ix; int i = (PL_regsize - parenfloor) * 4; int p; SSCHECK(i + 5); for (p = PL_regsize; p > parenfloor; p--) { SSPUSHPTR(PL_regendp[p]); SSPUSHPTR(PL_regstartp[p]); SSPUSHPTR(PL_reg_start_tmp[p]); SSPUSHINT(p); } SSPUSHINT(PL_regsize); SSPUSHINT(*PL_reglastparen); SSPUSHPTR(PL_reginput); SSPUSHINT(i + 3); SSPUSHINT(SAVEt_REGCONTEXT); return retval; } /* These are needed since we do not localize EVAL nodes: */ # define REGCP_SET DEBUG_r(PerlIO_printf(Perl_debug_log, \ " Setting an EVAL scope, savestack=%i\n", \ PL_savestack_ix)); lastcp = PL_savestack_ix # define REGCP_UNWIND DEBUG_r(lastcp != PL_savestack_ix ? \ PerlIO_printf(Perl_debug_log, \ " Clearing an EVAL scope, savestack=%i..%i\n", \ lastcp, PL_savestack_ix) : 0); regcpblow(lastcp) STATIC char * regcppop(void) { dTHR; I32 i = SSPOPINT; U32 paren = 0; char *input; char *tmps; assert(i == SAVEt_REGCONTEXT); i = SSPOPINT; input = (char *) SSPOPPTR; *PL_reglastparen = SSPOPINT; PL_regsize = SSPOPINT; for (i -= 3; i > 0; i -= 4) { paren = (U32)SSPOPINT; PL_reg_start_tmp[paren] = (char *) SSPOPPTR; PL_regstartp[paren] = (char *) SSPOPPTR; tmps = (char*)SSPOPPTR; if (paren <= *PL_reglastparen) PL_regendp[paren] = tmps; DEBUG_r( PerlIO_printf(Perl_debug_log, " restoring \\%d to %d(%d)..%d%s\n", paren, PL_regstartp[paren] - PL_regbol, PL_reg_start_tmp[paren] - PL_regbol, PL_regendp[paren] - PL_regbol, (paren > *PL_reglastparen ? "(no)" : "")); ); } DEBUG_r( if (*PL_reglastparen + 1 <= PL_regnpar) { PerlIO_printf(Perl_debug_log, " restoring \\%d..\\%d to undef\n", *PL_reglastparen + 1, PL_regnpar); } ); for (paren = *PL_reglastparen + 1; paren <= PL_regnpar; paren++) { if (paren > PL_regsize) PL_regstartp[paren] = Nullch; PL_regendp[paren] = Nullch; } return input; } #define regcpblow(cp) LEAVE_SCOPE(cp) /* * pregexec and friends */ /* - pregexec - match a regexp against a string */ I32 pregexec(register regexp *prog, char *stringarg, register char *strend, char *strbeg, I32 minend, SV *screamer, U32 nosave) /* strend: pointer to null at end of string */ /* strbeg: real beginning of string */ /* minend: end of match must be >=minend after stringarg. */ /* nosave: For optimizations. */ { return regexec_flags(prog, stringarg, strend, strbeg, minend, screamer, NULL, nosave ? 0 : REXEC_COPY_STR); } /* - regexec_flags - match a regexp against a string */ I32 regexec_flags(register regexp *prog, char *stringarg, register char *strend, char *strbeg, I32 minend, SV *screamer, void *data, U32 flags) /* strend: pointer to null at end of string */ /* strbeg: real beginning of string */ /* minend: end of match must be >=minend after stringarg. */ /* data: May be used for some additional optimizations. */ /* nosave: For optimizations. */ { dTHR; register char *s; register regnode *c; register char *startpos = stringarg; register I32 tmp; I32 minlen; /* must match at least this many chars */ I32 dontbother = 0; /* how many characters not to try at end */ CURCUR cc; I32 start_shift = 0; /* Offset of the start to find constant substr. */ I32 end_shift = 0; /* Same for the end. */ I32 scream_pos = -1; /* Internal iterator of scream. */ char *scream_olds; SV* oreplsv = GvSV(PL_replgv); cc.cur = 0; cc.oldcc = 0; PL_regcc = &cc; PL_regprecomp = prog->precomp; /* Needed for error messages. */ #ifdef DEBUGGING PL_regnarrate = PL_debug & 512; PL_regprogram = prog->program; #endif /* Be paranoid... */ if (prog == NULL || startpos == NULL) { croak("NULL regexp parameter"); return 0; } minlen = prog->minlen; if (strend - startpos < minlen) goto phooey; if (startpos == strbeg) /* is ^ valid at stringarg? */ PL_regprev = '\n'; else { PL_regprev = stringarg[-1]; if (!PL_multiline && PL_regprev == '\n') PL_regprev = '\0'; /* force ^ to NOT match */ } /* Check validity of program. */ if (UCHARAT(prog->program) != MAGIC) { FAIL("corrupted regexp program"); } PL_regnpar = prog->nparens; PL_reg_flags = 0; PL_reg_eval_set = 0; /* If there is a "must appear" string, look for it. */ s = startpos; if (!(flags & REXEC_CHECKED) && prog->check_substr != Nullsv && !(prog->reganch & ROPT_ANCH_GPOS) && (!(prog->reganch & (ROPT_ANCH_BOL | ROPT_ANCH_MBOL)) || (PL_multiline && prog->check_substr == prog->anchored_substr)) ) { start_shift = prog->check_offset_min; /* Should be nonnegative! */ end_shift = minlen - start_shift - SvCUR(prog->check_substr); if (screamer) { if (PL_screamfirst[BmRARE(prog->check_substr)] >= 0) s = screaminstr(screamer, prog->check_substr, start_shift + (stringarg - strbeg), end_shift, &scream_pos, 0); else s = Nullch; scream_olds = s; } else s = fbm_instr((unsigned char*)s + start_shift, (unsigned char*)strend - end_shift, prog->check_substr, 0); if (!s) { ++BmUSEFUL(prog->check_substr); /* hooray */ goto phooey; /* not present */ } else if ((s - stringarg) > prog->check_offset_max) { ++BmUSEFUL(prog->check_substr); /* hooray/2 */ s -= prog->check_offset_max; } else if (!prog->naughty && --BmUSEFUL(prog->check_substr) < 0 && prog->check_substr == prog->float_substr) { /* boo */ SvREFCNT_dec(prog->check_substr); prog->check_substr = Nullsv; /* disable */ prog->float_substr = Nullsv; /* clear */ s = startpos; } else s = startpos; } /* Mark beginning of line for ^ and lookbehind. */ PL_regbol = startpos; PL_bostr = strbeg; /* Mark end of line for $ (and such) */ PL_regeol = strend; /* see how far we have to get to not match where we matched before */ PL_regtill = startpos+minend; DEBUG_r( PerlIO_printf(Perl_debug_log, "Matching `%.60s%s' against `%.*s%s'\n", prog->precomp, (strlen(prog->precomp) > 60 ? "..." : ""), (strend - startpos > 60 ? 60 : strend - startpos), startpos, (strend - startpos > 60 ? "..." : "")) ); /* Simplest case: anchored match need be tried only once. */ /* [unless only anchor is BOL and multiline is set] */ if (prog->reganch & ROPT_ANCH) { if (regtry(prog, startpos)) goto got_it; else if (!(prog->reganch & ROPT_ANCH_GPOS) && (PL_multiline || (prog->reganch & ROPT_IMPLICIT) || (prog->reganch & ROPT_ANCH_MBOL))) { if (minlen) dontbother = minlen - 1; strend -= dontbother; /* for multiline we only have to try after newlines */ if (s > startpos) s--; while (s < strend) { if (*s++ == '\n') { if (s < strend && regtry(prog, s)) goto got_it; } } } goto phooey; } /* Messy cases: unanchored match. */ if (prog->anchored_substr && prog->reganch & ROPT_SKIP) { /* we have /x+whatever/ */ /* it must be a one character string */ char ch = SvPVX(prog->anchored_substr)[0]; while (s < strend) { if (*s == ch) { if (regtry(prog, s)) goto got_it; s++; while (s < strend && *s == ch) s++; } s++; } } /*SUPPRESS 560*/ else if (prog->anchored_substr != Nullsv || (prog->float_substr != Nullsv && prog->float_max_offset < strend - s)) { SV *must = prog->anchored_substr ? prog->anchored_substr : prog->float_substr; I32 back_max = prog->anchored_substr ? prog->anchored_offset : prog->float_max_offset; I32 back_min = prog->anchored_substr ? prog->anchored_offset : prog->float_min_offset; I32 delta = back_max - back_min; char *last = strend - SvCUR(must) - back_min; /* Cannot start after this */ char *last1 = s - 1; /* Last position checked before */ /* XXXX check_substr already used to find `s', can optimize if check_substr==must. */ scream_pos = -1; dontbother = end_shift; strend -= dontbother; while ( (s <= last) && (screamer ? (s = screaminstr(screamer, must, s + back_min - strbeg, end_shift, &scream_pos, 0)) : (s = fbm_instr((unsigned char*)s + back_min, (unsigned char*)strend, must, 0))) ) { if (s - back_max > last1) { last1 = s - back_min; s = s - back_max; } else { char *t = last1 + 1; last1 = s - back_min; s = t; } while (s <= last1) { if (regtry(prog, s)) goto got_it; s++; } } goto phooey; } else if (c = prog->regstclass) { I32 doevery = (prog->reganch & ROPT_SKIP) == 0; char *Class; if (minlen) dontbother = minlen - 1; strend -= dontbother; /* don't bother with what can't match */ tmp = 1; /* We know what class it must start with. */ switch (OP(c)) { case ANYOF: Class = (char *) OPERAND(c); while (s < strend) { if (REGINCLASS(Class, *s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case BOUNDL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case BOUND: if (minlen) dontbother++,strend--; tmp = (s != startpos) ? UCHARAT(s - 1) : PL_regprev; tmp = ((OP(c) == BOUND ? isALNUM(tmp) : isALNUM_LC(tmp)) != 0); while (s < strend) { if (tmp == !(OP(c) == BOUND ? isALNUM(*s) : isALNUM_LC(*s))) { tmp = !tmp; if (regtry(prog, s)) goto got_it; } s++; } if ((minlen || tmp) && regtry(prog,s)) goto got_it; break; case NBOUNDL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case NBOUND: if (minlen) dontbother++,strend--; tmp = (s != startpos) ? UCHARAT(s - 1) : PL_regprev; tmp = ((OP(c) == NBOUND ? isALNUM(tmp) : isALNUM_LC(tmp)) != 0); while (s < strend) { if (tmp == !(OP(c) == NBOUND ? isALNUM(*s) : isALNUM_LC(*s))) tmp = !tmp; else if (regtry(prog, s)) goto got_it; s++; } if ((minlen || !tmp) && regtry(prog,s)) goto got_it; break; case ALNUM: while (s < strend) { if (isALNUM(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case ALNUML: PL_reg_flags |= RF_tainted; while (s < strend) { if (isALNUM_LC(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case NALNUM: while (s < strend) { if (!isALNUM(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case NALNUML: PL_reg_flags |= RF_tainted; while (s < strend) { if (!isALNUM_LC(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case SPACE: while (s < strend) { if (isSPACE(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case SPACEL: PL_reg_flags |= RF_tainted; while (s < strend) { if (isSPACE_LC(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case NSPACE: while (s < strend) { if (!isSPACE(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case NSPACEL: PL_reg_flags |= RF_tainted; while (s < strend) { if (!isSPACE_LC(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case DIGIT: while (s < strend) { if (isDIGIT(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; case NDIGIT: while (s < strend) { if (!isDIGIT(*s)) { if (tmp && regtry(prog, s)) goto got_it; else tmp = doevery; } else tmp = 1; s++; } break; } } else { dontbother = 0; if (prog->float_substr != Nullsv) { /* Trim the end. */ char *last; I32 oldpos = scream_pos; if (screamer) { last = screaminstr(screamer, prog->float_substr, s - strbeg, end_shift, &scream_pos, 1); /* last one */ if (!last) { last = scream_olds; /* Only one occurence. */ } } else { STRLEN len; char *little = SvPV(prog->float_substr, len); if (len) last = rninstr(s, strend, little, little + len); else last = strend; /* matching `$' */ } if (last == NULL) goto phooey; /* Should not happen! */ dontbother = strend - last + prog->float_min_offset; } if (minlen && (dontbother < minlen)) dontbother = minlen - 1; strend -= dontbother; /* We don't know much -- general case. */ do { if (regtry(prog, s)) goto got_it; } while (s++ < strend); } /* Failure. */ goto phooey; got_it: prog->subbeg = strbeg; prog->subend = PL_regeol; /* strend may have been modified */ RX_MATCH_TAINTED_set(prog, PL_reg_flags & RF_tainted); /* make sure $`, $&, $', and $digit will work later */ if (strbeg != prog->subbase) { /* second+ //g match. */ if (!(flags & REXEC_COPY_STR)) { if (prog->subbase) { Safefree(prog->subbase); prog->subbase = Nullch; } } else { I32 i = PL_regeol - startpos + (stringarg - strbeg); s = savepvn(strbeg, i); Safefree(prog->subbase); prog->subbase = s; prog->subbeg = prog->subbase; prog->subend = prog->subbase + i; s = prog->subbase + (stringarg - strbeg); for (i = 0; i <= prog->nparens; i++) { if (prog->endp[i]) { prog->startp[i] = s + (prog->startp[i] - startpos); prog->endp[i] = s + (prog->endp[i] - startpos); } } } } /* Preserve the current value of $^R */ if (oreplsv != GvSV(PL_replgv)) { sv_setsv(oreplsv, GvSV(PL_replgv));/* So that when GvSV(replgv) is restored, the value remains the same. */ } return 1; phooey: return 0; } /* - regtry - try match at specific point */ STATIC I32 /* 0 failure, 1 success */ regtry(regexp *prog, char *startpos) { dTHR; register I32 i; register char **sp; register char **ep; CHECKPOINT lastcp; if ((prog->reganch & ROPT_EVAL_SEEN) && !PL_reg_eval_set) { PL_reg_eval_set = RS_init; DEBUG_r(DEBUG_s( PerlIO_printf(Perl_debug_log, " setting stack tmpbase at %i\n", PL_stack_sp - PL_stack_base); )); SAVEINT(cxstack[cxstack_ix].blk_oldsp); cxstack[cxstack_ix].blk_oldsp = PL_stack_sp - PL_stack_base; /* Otherwise OP_NEXTSTATE will free whatever on stack now. */ SAVETMPS; /* Apparently this is not needed, judging by wantarray. */ /* SAVEINT(cxstack[cxstack_ix].blk_gimme); cxstack[cxstack_ix].blk_gimme = G_SCALAR; */ } PL_reginput = startpos; PL_regstartp = prog->startp; PL_regendp = prog->endp; PL_reglastparen = &prog->lastparen; prog->lastparen = 0; PL_regsize = 0; if (PL_reg_start_tmpl <= prog->nparens) { PL_reg_start_tmpl = prog->nparens*3/2 + 3; if(PL_reg_start_tmp) Renew(PL_reg_start_tmp, PL_reg_start_tmpl, char*); else New(22,PL_reg_start_tmp, PL_reg_start_tmpl, char*); } sp = prog->startp; ep = prog->endp; PL_regdata = prog->data; if (prog->nparens) { for (i = prog->nparens; i >= 0; i--) { *sp++ = NULL; *ep++ = NULL; } } REGCP_SET; if (regmatch(prog->program + 1)) { prog->startp[0] = startpos; prog->endp[0] = PL_reginput; return 1; } REGCP_UNWIND; return 0; } /* - regmatch - main matching routine * * Conceptually the strategy is simple: check to see whether the current * node matches, call self recursively to see whether the rest matches, * and then act accordingly. In practice we make some effort to avoid * recursion, in particular by going through "ordinary" nodes (that don't * need to know whether the rest of the match failed) by a loop instead of * by recursion. */ /* [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. */ STATIC I32 /* 0 failure, 1 success */ regmatch(regnode *prog) { dTHR; 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; /* len or last */ register char *s; /* operand or save */ register char *locinput = PL_reginput; register I32 c1, c2, paren; /* case fold search, parenth */ int minmod = 0, sw = 0, logical = 0; #ifdef DEBUGGING PL_regindent++; #endif nextchr = UCHARAT(locinput); scan = prog; while (scan != NULL) { #define sayNO_L (logical ? (logical = 0, sw = 0, goto cont) : sayNO) #ifdef DEBUGGING # define sayYES goto yes # define sayNO goto no # define saySAME(x) if (x) goto yes; else goto no # define REPORT_CODE_OFF 24 #else # define sayYES return 1 # define sayNO return 0 # define saySAME(x) return x #endif DEBUG_r( { SV *prop = sv_newmortal(); int docolor = *PL_colors[0]; int taill = (docolor ? 10 : 7); /* 3 chars for "> <" */ int l = (PL_regeol - locinput > taill ? taill : PL_regeol - locinput); int pref_len = (locinput - PL_bostr > (5 + taill) - l ? (5 + taill) - l : locinput - PL_bostr); if (l + pref_len < (5 + taill) && l < PL_regeol - locinput) l = ( PL_regeol - locinput > (5 + taill) - pref_len ? (5 + taill) - pref_len : PL_regeol - locinput); regprop(prop, scan); PerlIO_printf(Perl_debug_log, "%4i <%s%.*s%s%s%s%.*s%s>%*s|%3d:%*s%s\n", locinput - PL_bostr, PL_colors[2], pref_len, locinput - pref_len, PL_colors[3], (docolor ? "" : "> <"), PL_colors[0], l, locinput, PL_colors[1], 15 - l - pref_len + 1, "", scan - PL_regprogram, PL_regindent*2, "", SvPVX(prop)); } ); next = scan + NEXT_OFF(scan); if (next == scan) next = NULL; switch (OP(scan)) { case BOL: if (locinput == PL_bostr ? PL_regprev == '\n' : (PL_multiline && (nextchr || locinput < PL_regeol) && locinput[-1] == '\n') ) { /* PL_regtill = PL_regbol; */ break; } sayNO; case MBOL: if (locinput == PL_bostr ? PL_regprev == '\n' : ((nextchr || locinput < PL_regeol) && locinput[-1] == '\n') ) { break; } sayNO; case SBOL: if (locinput == PL_regbol && PL_regprev == '\n') break; sayNO; case GPOS: if (locinput == PL_regbol) break; sayNO; case EOL: if (PL_multiline) goto meol; else goto seol; case MEOL: meol: if ((nextchr || locinput < PL_regeol) && nextchr != '\n') sayNO; break; case SEOL: seol: if ((nextchr || locinput < PL_regeol) && nextchr != '\n') sayNO; if (PL_regeol - locinput > 1) sayNO; break; case EOS: if (PL_regeol != locinput) sayNO; break; case SANY: if (!nextchr && locinput >= PL_regeol) sayNO; nextchr = UCHARAT(++locinput); break; case ANY: if (!nextchr && locinput >= PL_regeol || nextchr == '\n') sayNO; nextchr = UCHARAT(++locinput); break; case EXACT: s = (char *) OPERAND(scan); ln = UCHARAT(s++); /* Inline the first character, for speed. */ if (UCHARAT(s) != nextchr) sayNO; if (PL_regeol - locinput < ln) sayNO; if (ln > 1 && memNE(s, locinput, ln)) sayNO; locinput += ln; nextchr = UCHARAT(locinput); break; case EXACTFL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case EXACTF: s = (char *) OPERAND(scan); ln = UCHARAT(s++); /* Inline the first character, for speed. */ if (UCHARAT(s) != nextchr && UCHARAT(s) != ((OP(scan) == EXACTF) ? fold : fold_locale)[nextchr]) sayNO; if (PL_regeol - locinput < ln) sayNO; if (ln > 1 && (OP(scan) == EXACTF ? ibcmp(s, locinput, ln) : ibcmp_locale(s, locinput, ln))) sayNO; locinput += ln; nextchr = UCHARAT(locinput); break; case ANYOF: s = (char *) OPERAND(scan); if (nextchr < 0) nextchr = UCHARAT(locinput); if (!REGINCLASS(s, nextchr)) sayNO; if (!nextchr && locinput >= PL_regeol) sayNO; nextchr = UCHARAT(++locinput); break; case ALNUML: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case ALNUM: if (!nextchr) sayNO; if (!(OP(scan) == ALNUM ? isALNUM(nextchr) : isALNUM_LC(nextchr))) sayNO; nextchr = UCHARAT(++locinput); break; case NALNUML: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case NALNUM: if (!nextchr && locinput >= PL_regeol) sayNO; if (OP(scan) == NALNUM ? isALNUM(nextchr) : isALNUM_LC(nextchr)) sayNO; nextchr = UCHARAT(++locinput); break; case BOUNDL: case NBOUNDL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case BOUND: case NBOUND: /* was last char in word? */ ln = (locinput != PL_regbol) ? UCHARAT(locinput - 1) : PL_regprev; if (OP(scan) == BOUND || OP(scan) == NBOUND) { ln = isALNUM(ln); n = isALNUM(nextchr); } else { ln = isALNUM_LC(ln); n = isALNUM_LC(nextchr); } if (((!ln) == (!n)) == (OP(scan) == BOUND || OP(scan) == BOUNDL)) sayNO; break; case SPACEL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case SPACE: if (!nextchr && locinput >= PL_regeol) sayNO; if (!(OP(scan) == SPACE ? isSPACE(nextchr) : isSPACE_LC(nextchr))) sayNO; nextchr = UCHARAT(++locinput); break; case NSPACEL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case NSPACE: if (!nextchr) sayNO; if (OP(scan) == SPACE ? isSPACE(nextchr) : isSPACE_LC(nextchr)) sayNO; nextchr = UCHARAT(++locinput); break; case DIGIT: if (!isDIGIT(nextchr)) sayNO; nextchr = UCHARAT(++locinput); break; case NDIGIT: if (!nextchr && locinput >= PL_regeol) sayNO; if (isDIGIT(nextchr)) sayNO; nextchr = UCHARAT(++locinput); break; case REFFL: PL_reg_flags |= RF_tainted; /* FALL THROUGH */ case REF: case REFF: n = ARG(scan); /* which paren pair */ s = PL_regstartp[n]; if (*PL_reglastparen < n || !s) sayNO; /* Do not match unless seen CLOSEn. */ if (s == PL_regendp[n]) break; /* Inline the first character, for speed. */ if (UCHARAT(s) != nextchr && (OP(scan) == REF || (UCHARAT(s) != ((OP(scan) == REFF ? fold : fold_locale)[nextchr])))) sayNO; ln = PL_regendp[n] - s; if (locinput + ln > PL_regeol) sayNO; if (ln > 1 && (OP(scan) == REF ? memNE(s, locinput, ln) : (OP(scan) == REFF ? ibcmp(s, locinput, ln) : ibcmp_locale(s, locinput, ln)))) sayNO; locinput += ln; nextchr = UCHARAT(locinput); break; case NOTHING: case TAIL: break; case BACK: break; case EVAL: { dSP; OP_4tree *oop = PL_op; COP *ocurcop = PL_curcop; SV **ocurpad = PL_curpad; SV *ret; n = ARG(scan); PL_op = (OP_4tree*)PL_regdata->data[n]; DEBUG_r( PerlIO_printf(Perl_debug_log, " re_eval 0x%x\n", PL_op) ); PL_curpad = AvARRAY((AV*)PL_regdata->data[n + 1]); CALLRUNOPS(); /* Scalar context. */ SPAGAIN; ret = POPs; PUTBACK; if (logical) { logical = 0; sw = SvTRUE(ret); } else sv_setsv(save_scalar(PL_replgv), ret); PL_op = oop; PL_curpad = ocurpad; PL_curcop = ocurcop; break; } case OPEN: n = ARG(scan); /* which paren pair */ PL_reg_start_tmp[n] = locinput; if (n > PL_regsize) PL_regsize = n; break; case CLOSE: n = ARG(scan); /* which paren pair */ PL_regstartp[n] = PL_reg_start_tmp[n]; PL_regendp[n] = locinput; if (n > *PL_reglastparen) *PL_reglastparen = n; break; case GROUPP: n = ARG(scan); /* which paren pair */ sw = (*PL_reglastparen >= n && PL_regendp[n] != NULL); break; case IFTHEN: if (sw) next = NEXTOPER(NEXTOPER(scan)); else { next = scan + ARG(scan); if (OP(next) == IFTHEN) /* Fake one. */ next = NEXTOPER(NEXTOPER(next)); } break; case LOGICAL: logical = 1; break; case CURLYX: { CURCUR cc; CHECKPOINT cp = PL_savestack_ix; if (OP(PREVOPER(next)) == NOTHING) /* LONGJMP */ next += ARG(next); cc.oldcc = PL_regcc; PL_regcc = &cc; cc.parenfloor = *PL_reglastparen; 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 */ regcpblow(cp); PL_regcc = cc.oldcc; saySAME(n); } /* NOT REACHED */ case WHILEM: { /* * This is really hard to understand, because after we match * what we're trying to match, we must make sure the rest of * the RE is going to match for sure, and to do that we have * to go back UP the parse tree by recursing ever deeper. And * if it fails, we have to reset our parent's current state * that we can try again after backing off. */ CHECKPOINT cp, lastcp; CURCUR* cc = PL_regcc; char *lastloc = cc->lastloc; /* Detection of 0-len. */ n = cc->cur + 1; /* how many we know we matched */ PL_reginput = locinput; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s %ld out of %ld..%ld cc=%lx\n", REPORT_CODE_OFF+PL_regindent*2, "", (long)n, (long)cc->min, (long)cc->max, (long)cc) ); /* If degenerate scan matches "", assume scan done. */ if (locinput == cc->lastloc && n >= cc->min) { PL_regcc = cc->oldcc; ln = PL_regcc->cur; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s empty match detected, try continuation...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); if (regmatch(cc->next)) sayYES; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s failed...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); PL_regcc->cur = ln; PL_regcc = cc; sayNO; } /* First just match a string of min scans. */ if (n < cc->min) { cc->cur = n; cc->lastloc = locinput; if (regmatch(cc->scan)) sayYES; cc->cur = n - 1; cc->lastloc = lastloc; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s failed...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); sayNO; } /* Prefer next over scan for minimal matching. */ if (cc->minmod) { PL_regcc = cc->oldcc; ln = PL_regcc->cur; cp = regcppush(cc->parenfloor); REGCP_SET; if (regmatch(cc->next)) { regcpblow(cp); sayYES; /* All done. */ } REGCP_UNWIND; regcppop(); PL_regcc->cur = ln; PL_regcc = cc; if (n >= cc->max) { /* Maximum greed exceeded? */ if (PL_dowarn && n >= REG_INFTY && !(PL_reg_flags & RF_warned)) { PL_reg_flags |= RF_warned; warn("%s limit (%d) exceeded", "Complex regular subexpression recursion", REG_INFTY - 1); } sayNO; } DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s trying longer...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); /* Try scanning more and see if it helps. */ PL_reginput = locinput; cc->cur = n; cc->lastloc = locinput; cp = regcppush(cc->parenfloor); REGCP_SET; if (regmatch(cc->scan)) { regcpblow(cp); sayYES; } DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s failed...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); REGCP_UNWIND; regcppop(); cc->cur = n - 1; cc->lastloc = lastloc; sayNO; } /* Prefer scan over next for maximal matching. */ if (n < cc->max) { /* More greed allowed? */ cp = regcppush(cc->parenfloor); cc->cur = n; cc->lastloc = locinput; REGCP_SET; if (regmatch(cc->scan)) { regcpblow(cp); sayYES; } REGCP_UNWIND; regcppop(); /* Restore some previous $s? */ PL_reginput = locinput; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s failed, try continuation...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); } if (PL_dowarn && n >= REG_INFTY && !(PL_reg_flags & RF_warned)) { PL_reg_flags |= RF_warned; warn("%s limit (%d) exceeded", "Complex regular subexpression recursion", REG_INFTY - 1); } /* Failed deeper matches of scan, so see if this one works. */ PL_regcc = cc->oldcc; ln = PL_regcc->cur; if (regmatch(cc->next)) sayYES; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s failed...\n", REPORT_CODE_OFF+PL_regindent*2, "") ); PL_regcc->cur = ln; PL_regcc = cc; cc->cur = n - 1; cc->lastloc = lastloc; sayNO; } /* NOT REACHED */ case BRANCHJ: next = scan + ARG(scan); if (next == scan) next = NULL; inner = NEXTOPER(NEXTOPER(scan)); goto do_branch; case BRANCH: inner = NEXTOPER(scan); do_branch: { CHECKPOINT lastcp; c1 = OP(scan); if (OP(next) != c1) /* No choice. */ next = inner; /* Avoid recursion. */ else { int lastparen = *PL_reglastparen; REGCP_SET; do { PL_reginput = locinput; if (regmatch(inner)) sayYES; REGCP_UNWIND; for (n = *PL_reglastparen; n > lastparen; n--) PL_regendp[n] = 0; *PL_reglastparen = n; scan = next; /*SUPPRESS 560*/ if (n = (c1 == BRANCH ? NEXT_OFF(next) : ARG(next))) next += n; else next = NULL; inner = NEXTOPER(scan); if (c1 == BRANCHJ) { inner = NEXTOPER(inner); } } while (scan != NULL && OP(scan) == c1); sayNO; /* NOTREACHED */ } } break; case MINMOD: minmod = 1; break; case CURLYM: { I32 l = 0; CHECKPOINT lastcp; /* We suppose that the next guy does not need backtracking: in particular, it is of constant length, and has no parenths to influence future backrefs. */ ln = ARG1(scan); /* min to match */ n = ARG2(scan); /* max to match */ paren = scan->flags; if (paren) { if (paren > PL_regsize) PL_regsize = paren; if (paren > *PL_reglastparen) *PL_reglastparen = paren; } scan = NEXTOPER(scan) + NODE_STEP_REGNODE; if (paren) scan += NEXT_OFF(scan); /* Skip former OPEN. */ PL_reginput = locinput; if (minmod) { minmod = 0; if (ln && regrepeat_hard(scan, ln, &l) < ln) sayNO; if (ln && l == 0 && n >= ln /* In fact, this is tricky. If paren, then the fact that we did/didnot match may influence future execution. */ && !(paren && ln == 0)) ln = n; locinput = PL_reginput; if (regkind[(U8)OP(next)] == EXACT) { c1 = UCHARAT(OPERAND(next) + 1); if (OP(next) == EXACTF) c2 = fold[c1]; else if (OP(next) == EXACTFL) c2 = fold_locale[c1]; else c2 = c1; } else c1 = c2 = -1000; REGCP_SET; /* This may be improved if l == 0. */ while (n >= ln || (n == REG_INFTY && ln > 0 && l)) { /* ln overflow ? */ /* If it could work, try it. */ if (c1 == -1000 || UCHARAT(PL_reginput) == c1 || UCHARAT(PL_reginput) == c2) { if (paren) { if (n) { PL_regstartp[paren] = PL_reginput - l; PL_regendp[paren] = PL_reginput; } else PL_regendp[paren] = NULL; } if (regmatch(next)) sayYES; REGCP_UNWIND; } /* Couldn't or didn't -- move forward. */ PL_reginput = locinput; if (regrepeat_hard(scan, 1, &l)) { ln++; locinput = PL_reginput; } else sayNO; } } else { n = regrepeat_hard(scan, n, &l); if (n != 0 && l == 0 /* In fact, this is tricky. If paren, then the fact that we did/didnot match may influence future execution. */ && !(paren && ln == 0)) ln = n; locinput = PL_reginput; DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s matched %ld times, len=%ld...\n", REPORT_CODE_OFF+PL_regindent*2, "", n, l) ); if (n >= ln) { if (regkind[(U8)OP(next)] == EXACT) { c1 = UCHARAT(OPERAND(next) + 1); if (OP(next) == EXACTF) c2 = fold[c1]; else if (OP(next) == EXACTFL) c2 = fold_locale[c1]; else c2 = c1; } else c1 = c2 = -1000; } REGCP_SET; while (n >= ln) { /* If it could work, try it. */ if (c1 == -1000 || UCHARAT(PL_reginput) == c1 || UCHARAT(PL_reginput) == c2) { DEBUG_r( PerlIO_printf(Perl_debug_log, "%*s trying tail with n=%ld...\n", REPORT_CODE_OFF+PL_regindent*2, "", n) ); if (paren) { if (n) { PL_regstartp[paren] = PL_reginput - l; PL_regendp[paren] = PL_reginput; } else PL_regendp[paren] = NULL; } if (regmatch(next)) sayYES; REGCP_UNWIND; } /* Couldn't or didn't -- back up. */ n--; locinput -= l; PL_reginput = locinput; } } sayNO; break; } case CURLYN: paren = scan->flags; /* Which paren to set */ if (paren > PL_regsize) PL_regsize = paren; if (paren > *PL_reglastparen) *PL_reglastparen = paren; ln = ARG1(scan); /* min to match */ n = ARG2(scan); /* max to match */ scan = regnext(NEXTOPER(scan) + NODE_STEP_REGNODE); goto repeat; case CURLY: paren = 0; ln = ARG1(scan); /* min to match */ n = ARG2(scan); /* max to match */ scan = NEXTOPER(scan) + NODE_STEP_REGNODE; goto repeat; case STAR: ln = 0; n = REG_INFTY; scan = NEXTOPER(scan); paren = 0; goto repeat; case PLUS: ln = 1; n = REG_INFTY; scan = NEXTOPER(scan); paren = 0; repeat: /* * Lookahead to avoid useless match attempts * when we know what character comes next. */ if (regkind[(U8)OP(next)] == EXACT) { c1 = UCHARAT(OPERAND(next) + 1); if (OP(next) == EXACTF) c2 = fold[c1]; else if (OP(next) == EXACTFL) c2 = fold_locale[c1]; else c2 = c1; } else c1 = c2 = -1000; PL_reginput = locinput; if (minmod) { CHECKPOINT lastcp; minmod = 0; if (ln && regrepeat(scan, ln) < ln) sayNO; REGCP_SET; while (n >= ln || (n == REG_INFTY && ln > 0)) { /* ln overflow ? */ /* If it could work, try it. */ if (c1 == -1000 || UCHARAT(PL_reginput) == c1 || UCHARAT(PL_reginput) == c2) { if (paren) { if (n) { PL_regstartp[paren] = PL_reginput - 1; PL_regendp[paren] = PL_reginput; } else PL_regendp[paren] = NULL; } if (regmatch(next)) sayYES; REGCP_UNWIND; } /* Couldn't or didn't -- move forward. */ PL_reginput = locinput + ln; if (regrepeat(scan, 1)) { ln++; PL_reginput = locinput + ln; } else sayNO; } } else { CHECKPOINT lastcp; n = regrepeat(scan, n); if (ln < n && regkind[(U8)OP(next)] == EOL && (!PL_multiline || OP(next) == SEOL)) ln = n; /* why back off? */ REGCP_SET; if (paren) { while (n >= ln) { /* If it could work, try it. */ if (c1 == -1000 || UCHARAT(PL_reginput) == c1 || UCHARAT(PL_reginput) == c2) { if (paren && n) { if (n) { PL_regstartp[paren] = PL_reginput - 1; PL_regendp[paren] = PL_reginput; } else PL_regendp[paren] = NULL; } if (regmatch(next)) sayYES; REGCP_UNWIND; } /* Couldn't or didn't -- back up. */ n--; PL_reginput = locinput + n; } } else { while (n >= ln) { /* If it could work, try it. */ if (c1 == -1000 || UCHARAT(PL_reginput) == c1 || UCHARAT(PL_reginput) == c2) { if (regmatch(next)) sayYES; REGCP_UNWIND; } /* Couldn't or didn't -- back up. */ n--; PL_reginput = locinput + n; } } } sayNO; break; case END: if (locinput < PL_regtill) sayNO; /* Cannot match: too short. */ /* Fall through */ case SUCCEED: PL_reginput = locinput; /* put where regtry can find it */ sayYES; /* Success! */ case SUSPEND: n = 1; PL_reginput = locinput; goto do_ifmatch; case UNLESSM: n = 0; if (locinput < PL_bostr + scan->flags) goto say_yes; goto do_ifmatch; case IFMATCH: n = 1; if (locinput < PL_bostr + scan->flags) goto say_no; do_ifmatch: PL_reginput = locinput - scan->flags; inner = NEXTOPER(NEXTOPER(scan)); if (regmatch(inner) != n) { say_no: if (logical) { logical = 0; sw = 0; goto do_longjump; } else sayNO; } say_yes: if (logical) { logical = 0; sw = 1; } if (OP(scan) == SUSPEND) { locinput = PL_reginput; nextchr = UCHARAT(locinput); } /* FALL THROUGH. */ case LONGJMP: do_longjump: next = scan + ARG(scan); if (next == scan) next = NULL; break; default: PerlIO_printf(PerlIO_stderr(), "%lx %d\n", (unsigned long)scan, OP(scan)); FAIL("regexp memory corruption"); } scan = next; } /* * We get here only if there's trouble -- normally "case END" is * the terminating point. */ FAIL("corrupted regexp pointers"); /*NOTREACHED*/ sayNO; yes: #ifdef DEBUGGING PL_regindent--; #endif return 1; no: #ifdef DEBUGGING PL_regindent--; #endif return 0; } /* - regrepeat - repeatedly match something simple, report how many */ /* * [This routine now assumes that it will only match on things of length 1. * That was true before, but now we assume scan - reginput is the count, * rather than incrementing count on every character.] */ STATIC I32 regrepeat(regnode *p, I32 max) { dTHR; register char *scan; register char *opnd; register I32 c; register char *loceol = PL_regeol; scan = PL_reginput; if (max != REG_INFTY && max < loceol - scan) loceol = scan + max; opnd = (char *) OPERAND(p); switch (OP(p)) { case ANY: while (scan < loceol && *scan != '\n') scan++; break; case SANY: scan = loceol; break; case EXACT: /* length of string is 1 */ c = UCHARAT(++opnd); while (scan < loceol && UCHARAT(scan) == c) scan++; break; case EXACTF: /* length of string is 1 */ c = UCHARAT(++opnd); while (scan < loceol && (UCHARAT(scan) == c || UCHARAT(scan) == fold[c])) scan++; break; case EXACTFL: /* length of string is 1 */ PL_reg_flags |= RF_tainted; c = UCHARAT(++opnd); while (scan < loceol && (UCHARAT(scan) == c || UCHARAT(scan) == fold_locale[c])) scan++; break; case ANYOF: while (scan < loceol && REGINCLASS(opnd, *scan)) scan++; break; case ALNUM: while (scan < loceol && isALNUM(*scan)) scan++; break; case ALNUML: PL_reg_flags |= RF_tainted; while (scan < loceol && isALNUM_LC(*scan)) scan++; break; case NALNUM: while (scan < loceol && !isALNUM(*scan)) scan++; break; case NALNUML: PL_reg_flags |= RF_tainted; while (scan < loceol && !isALNUM_LC(*scan)) scan++; break; case SPACE: while (scan < loceol && isSPACE(*scan)) scan++; break; case SPACEL: PL_reg_flags |= RF_tainted; while (scan < loceol && isSPACE_LC(*scan)) scan++; break; case NSPACE: while (scan < loceol && !isSPACE(*scan)) scan++; break; case NSPACEL: PL_reg_flags |= RF_tainted; while (scan < loceol && !isSPACE_LC(*scan)) scan++; break; case DIGIT: while (scan < loceol && isDIGIT(*scan)) scan++; break; case NDIGIT: while (scan < loceol && !isDIGIT(*scan)) scan++; break; default: /* Called on something of 0 width. */ break; /* So match right here or not at all. */ } c = scan - PL_reginput; PL_reginput = scan; DEBUG_r( { SV *prop = sv_newmortal(); regprop(prop, p); PerlIO_printf(Perl_debug_log, "%*s %s can match %ld times out of %ld...\n", REPORT_CODE_OFF+1, "", SvPVX(prop),c,max); }); return(c); } /* - regrepeat_hard - repeatedly match something, report total lenth and length * * The repeater is supposed to have constant length. */ STATIC I32 regrepeat_hard(regnode *p, I32 max, I32 *lp) { dTHR; register char *scan; register char *start; register char *loceol = PL_regeol; I32 l = 0; I32 count = 0, res = 1; if (!max) return 0; start = PL_reginput; while (PL_reginput < loceol && (scan = PL_reginput, res = regmatch(p))) { if (!count++) { *lp = l = PL_reginput - start; if (max != REG_INFTY && l*max < loceol - scan) loceol = scan + l*max; if (l == 0) return max; } } if (!res) PL_reginput = scan; return count; } /* - regclass - determine if a character falls into a character class */ STATIC bool reginclass(register char *p, register I32 c) { dTHR; char flags = *p; bool match = FALSE; c &= 0xFF; if (ANYOF_TEST(p, c)) match = TRUE; else if (flags & ANYOF_FOLD) { I32 cf; if (flags & ANYOF_LOCALE) { PL_reg_flags |= RF_tainted; cf = fold_locale[c]; } else cf = fold[c]; if (ANYOF_TEST(p, cf)) match = TRUE; } if (!match && (flags & ANYOF_ISA)) { PL_reg_flags |= RF_tainted; if (((flags & ANYOF_ALNUML) && isALNUM_LC(c)) || ((flags & ANYOF_NALNUML) && !isALNUM_LC(c)) || ((flags & ANYOF_SPACEL) && isSPACE_LC(c)) || ((flags & ANYOF_NSPACEL) && !isSPACE_LC(c))) { match = TRUE; } } return (flags & ANYOF_INVERT) ? !match : match; }