Hakim Cassimally is the new maintainer of the Perldoc modules
[p5sagit/p5-mst-13.2.git] / regexec.c
index 9ded511..daa8e00 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -56,7 +56,7 @@
  ****    Alterations to Henry's code are...
  ****
  ****    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- ****    2000, 2001, 2002, 2003, 2004, 2005, 2006, by Larry Wall and others
+ ****    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 by Larry Wall and others
  ****
  ****    You may distribute under the terms of either the GNU General Public
  ****    License or the Artistic License, as specified in the README file.
 /* TODO: Combine JUMPABLE and HAS_TEXT to cache OP(rn) */
 
 /* for use after a quantifier and before an EXACT-like node -- japhy */
-#define JUMPABLE(rn) ( \
-    OP(rn) == OPEN || OP(rn) == CLOSE || OP(rn) == EVAL || \
+/* it would be nice to rework regcomp.sym to generate this stuff. sigh */
+#define JUMPABLE(rn) (      \
+    OP(rn) == OPEN ||       \
+    (OP(rn) == CLOSE && (!cur_eval || cur_eval->u.eval.close_paren != ARG(rn))) || \
+    OP(rn) == EVAL ||   \
     OP(rn) == SUSPEND || OP(rn) == IFMATCH || \
     OP(rn) == PLUS || OP(rn) == MINMOD || \
+    OP(rn) == KEEPS || (PL_regkind[OP(rn)] == VERB) || \
     (PL_regkind[OP(rn)] == CURLY && ARG1(rn) > 0) \
 )
+#define IS_EXACT(rn) (PL_regkind[OP(rn)] == EXACT)
 
-#define HAS_TEXT(rn) ( \
-    PL_regkind[OP(rn)] == EXACT || PL_regkind[OP(rn)] == REF \
-)
+#define HAS_TEXT(rn) ( IS_EXACT(rn) || PL_regkind[OP(rn)] == REF )
+
+#if 0 
+/* Currently these are only used when PL_regkind[OP(rn)] == EXACT so
+   we don't need this definition. */
+#define IS_TEXT(rn)   ( OP(rn)==EXACT   || OP(rn)==REF   || OP(rn)==NREF   )
+#define IS_TEXTF(rn)  ( OP(rn)==EXACTF  || OP(rn)==REFF  || OP(rn)==NREFF  )
+#define IS_TEXTFL(rn) ( OP(rn)==EXACTFL || OP(rn)==REFFL || OP(rn)==NREFFL )
+
+#else
+/* ... so we use this as its faster. */
+#define IS_TEXT(rn)   ( OP(rn)==EXACT   )
+#define IS_TEXTF(rn)  ( OP(rn)==EXACTF  )
+#define IS_TEXTFL(rn) ( OP(rn)==EXACTFL )
+
+#endif
 
 /*
   Search for mandatory following text node; for lookahead, the text must
@@ -483,7 +501,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
        /* end shift should be non negative here */
     }
 
-#ifdef DEBUGGING       /* 7/99: reports of failure (with the older version) */
+#ifdef QDEBUGGING      /* 7/99: reports of failure (with the older version) */
     if (end_shift < 0)
        Perl_croak(aTHX_ "panic: end_shift: %"IVdf" pattern:\n%s\n ",
                   (IV)end_shift, prog->precomp);
@@ -514,7 +532,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 
        if (PL_screamfirst[BmRARE(check)] >= 0
            || ( BmRARE(check) == '\n'
-                && (BmPREVIOUS(check) == (U8)SvCUR(check) - 1)
+                && (BmPREVIOUS(check) == SvCUR(check) - 1)
                 && SvTAIL(check) ))
            s = screaminstr(sv, check,
                            srch_start_shift + (s - strbeg), srch_end_shift, pp, 0);
@@ -1631,6 +1649,33 @@ S_find_byclass(pTHX_ regexp * prog, const regnode *c, char *s,
        return s;
 }
 
+void 
+S_swap_match_buff (pTHX_ regexp *prog) {
+    I32 *t;
+    RXi_GET_DECL(prog,progi);
+
+    if (!progi->swap) {
+    /* We have to be careful. If the previous successful match
+       was from this regex we don't want a subsequent paritally
+       successful match to clobber the old results. 
+       So when we detect this possibility we add a swap buffer
+       to the re, and switch the buffer each match. If we fail
+       we switch it back, otherwise we leave it swapped.
+    */
+        Newxz(progi->swap, 1, regexp_paren_ofs);
+        /* no need to copy these */
+        Newxz(progi->swap->startp, prog->nparens + 1, I32);
+        Newxz(progi->swap->endp, prog->nparens + 1, I32);
+    }
+    t = progi->swap->startp;
+    progi->swap->startp = prog->startp;
+    prog->startp = t;
+    t = progi->swap->endp;
+    progi->swap->endp = prog->endp;
+    prog->endp = t;
+}    
+
+
 /*
  - regexec_flags - match a regexp against a string
  */
@@ -1659,6 +1704,7 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
     I32 multiline;
     RXi_GET_DECL(prog,progi);
     regmatch_info reginfo;  /* create some info to pass to regtry etc */
+    bool swap_on_fail = 0;
 
     GET_RE_DEBUG_FLAGS_DECL;
 
@@ -1736,26 +1782,9 @@ Perl_regexec_flags(pTHX_ register regexp *prog, char *stringarg, register char *
            reginfo.ganch = strbeg;
     }
     if (PL_curpm && (PM_GETRE(PL_curpm) == prog)) {
-        I32 *t;
-        if (!progi->swap) {
-        /* We have to be careful. If the previous successful match
-           was from this regex we don't want a subsequent paritally
-           successful match to clobber the old results. 
-           So when we detect this possibility we add a swap buffer
-           to the re, and switch the buffer each match. If we fail
-           we switch it back, otherwise we leave it swapped.
-        */
-            Newxz(progi->swap, 1, regexp_paren_ofs);
-            /* no need to copy these */
-            Newxz(progi->swap->startp, prog->nparens + 1, I32);
-            Newxz(progi->swap->endp, prog->nparens + 1, I32);
-        }
-        t = progi->swap->startp;
-        progi->swap->startp = prog->startp;
-        prog->startp = t;
-        t = progi->swap->endp;
-        progi->swap->endp = prog->endp;
-        prog->endp = t;
+        swap_on_fail = 1;
+        swap_match_buff(prog); /* do we need a save destructor here for
+                                  eval dies? */
     }
     if (!(flags & REXEC_CHECKED) && (prog->check_substr != NULL || prog->check_utf8 != NULL)) {
        re_scream_pos_data d;
@@ -2105,20 +2134,16 @@ phooey:
                          PL_colors[4], PL_colors[5]));
     if (PL_reg_eval_set)
        restore_pos(aTHX_ prog);
-    if (progi->swap) {
+    if (swap_on_fail) 
         /* we failed :-( roll it back */
-        I32 *t;
-        t = progi->swap->startp;
-        progi->swap->startp = prog->startp;
-        prog->startp = t;
-        t = progi->swap->endp;
-        progi->swap->endp = prog->endp;
-        prog->endp = t;
-    }
+        swap_match_buff(prog);
+    
     return 0;
 }
 
 
+
+
 /*
  - regtry - try match at specific point
  */
@@ -2726,6 +2751,19 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
            if (locinput == reginfo->ganch)
                break;
            sayNO;
+
+       case KEEPS:
+           /* update the startpoint */
+           st->u.keeper.val = PL_regstartp[0];
+           PL_reginput = locinput;
+           PL_regstartp[0] = locinput - PL_bostr;
+           PUSH_STATE_GOTO(KEEPS_next, next);
+           /*NOT-REACHED*/
+       case KEEPS_next_fail:
+           /* rollback the start point change */
+           PL_regstartp[0] = st->u.keeper.val;
+           sayNO_SILENT;
+           /*NOT-REACHED*/
        case EOL:
                goto seol;
        case MEOL:
@@ -2839,7 +2877,6 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                ST.B = next;
                ST.jump = trie->jump;
                ST.me = scan;
-                
                /*
                   traverse the TRIE keeping track of all accepting states
                   we transition through until we get to a failing node.
@@ -2937,13 +2974,25 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                        PL_colors[4], (IV)ST.accepted, PL_colors[5] );
                );
            }}
-
-           /* FALL THROUGH */
+            goto trie_first_try; /* jump into the fail handler */
+           /* NOTREACHED */
        case TRIE_next_fail: /* we failed - try next alterative */
+            if ( ST.jump) {
+                REGCP_UNWIND(ST.cp);
+               for (n = *PL_reglastparen; n > ST.lastparen; n--)
+                   PL_regendp[n] = -1;
+               *PL_reglastparen = n;
+           }
+          trie_first_try:
             if (do_cutgroup) {
                 do_cutgroup = 0;
                 no_final = 0;
             }
+
+            if ( ST.jump) {
+                ST.lastparen = *PL_reglastparen;
+               REGCP_SET(ST.cp);
+            }          
            if ( ST.accepted == 1 ) {
                /* only one choice left - just continue */
                DEBUG_EXECUTE_r({
@@ -2984,8 +3033,8 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                
                continue; /* execute rest of RE */
            }
-
-           if (!ST.accepted-- ) {
+           
+           if ( !ST.accepted-- ) {
                DEBUG_EXECUTE_r({
                    PerlIO_printf( Perl_debug_log,
                        "%*s  %sTRIE failed...%s\n",
@@ -2996,7 +3045,8 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                FREETMPS;
                LEAVE;
                sayNO_SILENT;
-           }
+               /*NOTREACHED*/
+           } 
 
            /*
               There are at least two accepting states left.  Presumably
@@ -3546,6 +3596,9 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
             } else {
                 nochange_depth = 0;
             }    
+            {   regexp *ocurpm = PM_GETRE(PL_curpm);
+               char *osubbeg = rex->subbeg;
+               STRLEN osublen = rex->sublen;
            {
                /* execute the code in the {...} */
                dSP;
@@ -3553,6 +3606,7 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                OP_4tree * const oop = PL_op;
                COP * const ocurcop = PL_curcop;
                PAD *old_comppad;
+
            
                n = ARG(scan);
                PL_op = (OP_4tree*)rexi->data->data[n];
@@ -3565,6 +3619,10 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                     SV *sv_mrk = get_sv("REGMARK", 1);
                     sv_setsv(sv_mrk, sv_yes_mark);
                 }
+                /* make sure that $1 and friends are available with nested eval */
+                PM_SETRE(PL_curpm,rex);
+                rex->subbeg = ocurpm->subbeg;
+                rex->sublen = ocurpm->sublen;
 
                CALLRUNOPS(aTHX);                       /* Scalar context. */
                SPAGAIN;
@@ -3578,6 +3636,7 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                PL_op = oop;
                PAD_RESTORE_LOCAL(old_comppad);
                PL_curcop = ocurcop;
+
                if (!logical) {
                    /* /(?{...})/ */
                    sv_setsv(save_scalar(PL_replgv), ret);
@@ -3623,6 +3682,12 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                    }
                }
                rei = RXi_GET(re);
+
+                /* restore PL_curpm after the eval */
+                PM_SETRE(PL_curpm,ocurpm);
+                rex->sublen = osublen;
+                rex->subbeg = osubbeg;
+
                 DEBUG_EXECUTE_r(
                     debug_start_match(re, do_utf8, locinput, PL_regeol, 
                         "Matching embedded");
@@ -3636,7 +3701,8 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                         Renew(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
                     else
                         Newx(PL_reg_start_tmp, PL_reg_start_tmpl, char*);
-                }                      
+                }
+
 
         eval_recurse_doit: /* Share code with GOSUB below this line */                         
                /* run the pattern returned from (??{...}) */
@@ -3673,6 +3739,11 @@ S_regmatch(pTHX_ regmatch_info *reginfo, regnode *prog)
                PUSH_YES_STATE_GOTO(EVAL_AB, startpoint);
                /* NOTREACHED */
            }
+           /* restore PL_curpm after the eval */
+           PM_SETRE(PL_curpm,ocurpm);
+            rex->sublen = osublen;
+            rex->subbeg = osubbeg;
+           }
            /* logical is 1,   /(?(?{...})X|Y)/ */
            sw = (bool)SvTRUE(ret);
            logical = 0;
@@ -4292,14 +4363,23 @@ NULL
                    regnode *text_node = ST.B;
                    if (! HAS_TEXT(text_node))
                        FIND_NEXT_IMPT(text_node);
-                   if (HAS_TEXT(text_node)
-                       && PL_regkind[OP(text_node)] != REF)
+                   /* this used to be 
+                       
+                       (HAS_TEXT(text_node) && PL_regkind[OP(text_node)] == EXACT)
+                       
+                       But the former is redundant in light of the latter.
+                       
+                       if this changes back then the macro for 
+                       IS_TEXT and friends need to change.
+                    */
+                   if (PL_regkind[OP(text_node)] == EXACT)
                    {
+                       
                        ST.c1 = (U8)*STRING(text_node);
                        ST.c2 =
-                           (OP(text_node) == EXACTF || OP(text_node) == REFF)
+                           (IS_TEXTF(text_node))
                            ? PL_fold[ST.c1]
-                           : (OP(text_node) == EXACTFL || OP(text_node) == REFFL)
+                           : (IS_TEXTFL(text_node))
                                ? PL_fold_locale[ST.c1]
                                : ST.c1;
                    }
@@ -4317,6 +4397,12 @@ NULL
                    && UCHARAT(PL_reginput) != ST.c2)
            {
                /* simulate B failing */
+               DEBUG_OPTIMISE_r(
+                   PerlIO_printf(Perl_debug_log,
+                       "%*s  CURLYM Fast bail c1=%"IVdf" c2=%"IVdf"\n",
+                       (int)(REPORT_CODE_OFF+(depth*2)),"",
+                       (IV)ST.c1,(IV)ST.c2
+               ));
                state_num = CURLYM_B_fail;
                goto reenter_switch;
            }
@@ -4427,22 +4513,28 @@ NULL
                if (! HAS_TEXT(text_node))
                    ST.c1 = ST.c2 = CHRTEST_VOID;
                else {
-                   if (PL_regkind[OP(text_node)] == REF) {
+                   if ( PL_regkind[OP(text_node)] != EXACT ) {
                        ST.c1 = ST.c2 = CHRTEST_VOID;
                        goto assume_ok_easy;
                    }
                    else
                        s = (U8*)STRING(text_node);
-
+                    
+                    /*  Currently we only get here when 
+                        
+                        PL_rekind[OP(text_node)] == EXACT
+                    
+                        if this changes back then the macro for IS_TEXT and 
+                        friends need to change. */
                    if (!UTF) {
                        ST.c2 = ST.c1 = *s;
-                       if (OP(text_node) == EXACTF || OP(text_node) == REFF)
+                       if (IS_TEXTF(text_node))
                            ST.c2 = PL_fold[ST.c1];
-                       else if (OP(text_node) == EXACTFL || OP(text_node) == REFFL)
+                       else if (IS_TEXTFL(text_node))
                            ST.c2 = PL_fold_locale[ST.c1];
                    }
                    else { /* UTF */
-                       if (OP(text_node) == EXACTF || OP(text_node) == REFF) {
+                       if (IS_TEXTF(text_node)) {
                             STRLEN ulen1, ulen2;
                             U8 tmpbuf1[UTF8_MAXBYTES_CASE+1];
                             U8 tmpbuf2[UTF8_MAXBYTES_CASE+1];
@@ -4842,7 +4934,7 @@ NULL
                         PerlIO_printf(Perl_debug_log,
                            "%*s  %ssetting cutpoint to mark:%"SVf"...%s\n",
                            REPORT_CODE_OFF+depth*2, "", 
-                           PL_colors[4], sv_commit, PL_colors[5]);
+                           PL_colors[4], SVfARG(sv_commit), PL_colors[5]);
                });
             }
             mark_state = ST.prev_mark;
@@ -5624,10 +5716,18 @@ S_to_utf8_substr(pTHX_ register regexp *prog)
            SV* const sv = newSVsv(prog->substrs->data[i].substr);
            prog->substrs->data[i].utf8_substr = sv;
            sv_utf8_upgrade(sv);
-           if (SvVALID(prog->substrs->data[i].substr))
-               fbm_compile(sv, 0);
-           if (SvTAIL(prog->substrs->data[i].substr))
-               SvTAIL_on(sv);
+           if (SvVALID(prog->substrs->data[i].substr)) {
+               const U8 flags = BmFLAGS(prog->substrs->data[i].substr);
+               if (flags & FBMcf_TAIL) {
+                   /* Trim the trailing \n that fbm_compile added last
+                      time.  */
+                   SvCUR_set(sv, SvCUR(sv) - 1);
+                   /* Whilst this makes the SV technically "invalid" (as its
+                      buffer is no longer followed by "\0") when fbm_compile()
+                      adds the "\n" back, a "\0" is restored.  */
+               }
+               fbm_compile(sv, flags);
+           }
            if (prog->substrs->data[i].substr == prog->check_substr)
                prog->check_utf8 = sv;
        }
@@ -5644,10 +5744,16 @@ S_to_byte_substr(pTHX_ register regexp *prog)
            && !prog->substrs->data[i].substr) {
            SV* sv = newSVsv(prog->substrs->data[i].utf8_substr);
            if (sv_utf8_downgrade(sv, TRUE)) {
-               if (SvVALID(prog->substrs->data[i].utf8_substr))
-                   fbm_compile(sv, 0);
-               if (SvTAIL(prog->substrs->data[i].utf8_substr))
-                   SvTAIL_on(sv);
+               if (SvVALID(prog->substrs->data[i].utf8_substr)) {
+                   const U8 flags
+                       = BmFLAGS(prog->substrs->data[i].utf8_substr);
+                   if (flags & FBMcf_TAIL) {
+                       /* Trim the trailing \n that fbm_compile added last
+                          time.  */
+                       SvCUR_set(sv, SvCUR(sv) - 1);
+                   }
+                   fbm_compile(sv, flags);
+               }           
            } else {
                SvREFCNT_dec(sv);
                sv = &PL_sv_undef;