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support for C<exists &func> (from Spider Boardman)
[perl5.git] / op.c
diff --git a/op.c b/op.c
index a51ecb0..386e9de 100644 (file)
--- a/op.c
+++ b/op.c
 #include "keywords.h"
 
 /* #define PL_OP_SLAB_ALLOC */
-                                                            
+
+/* XXXXXX testing */
+#ifdef USE_ITHREADS
+#  define OP_REFCNT_LOCK               NOOP
+#  define OP_REFCNT_UNLOCK             NOOP
+#  define OpREFCNT_set(o,n)            ((o)->op_targ = (n))
+#  define OpREFCNT_dec(o)              (--(o)->op_targ)
+#else
+#  define OP_REFCNT_LOCK               NOOP
+#  define OP_REFCNT_UNLOCK             NOOP
+#  define OpREFCNT_set(o,n)            NOOP
+#  define OpREFCNT_dec(o)              0
+#endif
+
 #ifdef PL_OP_SLAB_ALLOC 
 #define SLAB_SIZE 8192
 static char    *PL_OpPtr  = NULL;
@@ -99,7 +112,7 @@ S_no_bareword_allowed(pTHX_ OP *o)
 {
     qerror(Perl_mess(aTHX_
                     "Bareword \"%s\" not allowed while \"strict subs\" in use",
-                    SvPV_nolen(cSVOPo->op_sv)));
+                    SvPV_nolen(cSVOPo_sv)));
 }
 
 /* "register" allocation */
@@ -146,11 +159,15 @@ Perl_pad_allocmy(pTHX_ char *name)
                && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
                && strEQ(name, SvPVX(sv)))
            {
-               Perl_warner(aTHX_ WARN_UNSAFE,
+               if (PL_in_my != KEY_our
+                   || GvSTASH(sv) == (PL_curstash ? PL_curstash : PL_defstash))
+               {
+                   Perl_warner(aTHX_ WARN_UNSAFE,
                        "\"%s\" variable %s masks earlier declaration in same %s", 
                        (PL_in_my == KEY_our ? "our" : "my"),
                        name,
                        (SvIVX(sv) == PAD_MAX ? "scope" : "statement"));
+               }
                break;
            }
        }
@@ -168,8 +185,11 @@ Perl_pad_allocmy(pTHX_ char *name)
        SvSTASH(sv) = (HV*)SvREFCNT_inc(PL_in_my_stash);
        PL_sv_objcount++;
     }
-    if (PL_in_my == KEY_our)
+    if (PL_in_my == KEY_our) {
+       (void)SvUPGRADE(sv, SVt_PVGV);
+       GvSTASH(sv) = (HV*)SvREFCNT_inc(PL_curstash ? PL_curstash : PL_defstash);
        SvFLAGS(sv) |= SVpad_OUR;
+    }
     av_store(PL_comppad_name, off, sv);
     SvNVX(sv) = (NV)PAD_MAX;
     SvIVX(sv) = 0;                     /* Not yet introduced--see newSTATEOP */
@@ -237,8 +257,11 @@ S_pad_findlex(pTHX_ char *name, PADOFFSET newoff, U32 seq, CV* startcv,
                    SvNVX(namesv) = (NV)PL_curcop->cop_seq;
                    SvIVX(namesv) = PAD_MAX;    /* A ref, intro immediately */
                    SvFAKE_on(namesv);          /* A ref, not a real var */
-                   if (SvFLAGS(sv) & SVpad_OUR)/* An "our" variable */
+                   if (SvFLAGS(sv) & SVpad_OUR) { /* An "our" variable */
                        SvFLAGS(namesv) |= SVpad_OUR;
+                       (void)SvUPGRADE(namesv, SVt_PVGV);
+                       GvSTASH(namesv) = (HV*)SvREFCNT_inc((SV*)GvSTASH(sv));
+                   }
                    if (SvOBJECT(sv)) {         /* A typed var */
                        SvOBJECT_on(namesv);
                        (void)SvUPGRADE(namesv, SVt_PVMG);
@@ -313,6 +336,7 @@ S_pad_findlex(pTHX_ char *name, PADOFFSET newoff, U32 seq, CV* startcv,
                return 0;
            }
            break;
+       case CXt_FORMAT:
        case CXt_SUB:
            if (!saweval)
                return 0;
@@ -442,7 +466,7 @@ Perl_pad_alloc(pTHX_ I32 optype, U32 tmptype)
                   (sv = names[PL_padix]) && sv != &PL_sv_undef)
                continue;
            sv = *av_fetch(PL_comppad, PL_padix, TRUE);
-           if (!(SvFLAGS(sv) & (SVs_PADTMP|SVs_PADMY)))
+           if (!(SvFLAGS(sv) & (SVs_PADTMP|SVs_PADMY)) && !IS_PADGV(sv))
                break;
        }
        retval = PL_padix;
@@ -450,12 +474,14 @@ Perl_pad_alloc(pTHX_ I32 optype, U32 tmptype)
     SvFLAGS(sv) |= tmptype;
     PL_curpad = AvARRAY(PL_comppad);
 #ifdef USE_THREADS
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "0x%lx Pad 0x%lx alloc %ld for %s\n",
-                         (unsigned long) thr, (unsigned long) PL_curpad,
+    DEBUG_X(PerlIO_printf(Perl_debug_log,
+                         "0x%"UVxf" Pad 0x%"UVxf" alloc %ld for %s\n",
+                         PTR2UV(thr), PTR2UV(PL_curpad),
                          (long) retval, PL_op_name[optype]));
 #else
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%lx alloc %ld for %s\n",
-                         (unsigned long) PL_curpad,
+    DEBUG_X(PerlIO_printf(Perl_debug_log,
+                         "Pad 0x%"UVxf" alloc %ld for %s\n",
+                         PTR2UV(PL_curpad),
                          (long) retval, PL_op_name[optype]));
 #endif /* USE_THREADS */
     return (PADOFFSET)retval;
@@ -466,13 +492,14 @@ Perl_pad_sv(pTHX_ PADOFFSET po)
 {
     dTHR;
 #ifdef USE_THREADS
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "0x%lx Pad 0x%lx sv %d\n",
-                         (unsigned long) thr, (unsigned long) PL_curpad, po));
+    DEBUG_X(PerlIO_printf(Perl_debug_log,
+                         "0x%"UVxf" Pad 0x%"UVxf" sv %"IVdf"\n",
+                         PTR2UV(thr), PTR2UV(PL_curpad), (IV)po));
 #else
     if (!po)
        Perl_croak(aTHX_ "panic: pad_sv po");
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%lx sv %d\n",
-                         (unsigned long) PL_curpad, po));
+    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%"UVxf" sv %"IVdf"\n",
+                         PTR2UV(PL_curpad), (IV)po));
 #endif /* USE_THREADS */
     return PL_curpad[po];              /* eventually we'll turn this into a macro */
 }
@@ -488,14 +515,19 @@ Perl_pad_free(pTHX_ PADOFFSET po)
     if (!po)
        Perl_croak(aTHX_ "panic: pad_free po");
 #ifdef USE_THREADS
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "0x%lx Pad 0x%lx free %d\n",
-                         (unsigned long) thr, (unsigned long) PL_curpad, po));
+    DEBUG_X(PerlIO_printf(Perl_debug_log,
+                         "0x%"UVxf" Pad 0x%"UVxf" free %"IVdf"\n",
+                         PTR2UV(thr), PTR2UV(PL_curpad), (IV)po));
 #else
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%lx free %d\n",
-                         (unsigned long) PL_curpad, po));
+    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%"UVxf" free %"IVdf"\n",
+                         PTR2UV(PL_curpad), (IV)po));
 #endif /* USE_THREADS */
-    if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef)
+    if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
        SvPADTMP_off(PL_curpad[po]);
+#ifdef USE_ITHREADS
+       SvREADONLY_off(PL_curpad[po]);  /* could be a freed constant */
+#endif
+    }
     if ((I32)po < PL_padix)
        PL_padix = po - 1;
 }
@@ -509,11 +541,12 @@ Perl_pad_swipe(pTHX_ PADOFFSET po)
     if (!po)
        Perl_croak(aTHX_ "panic: pad_swipe po");
 #ifdef USE_THREADS
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "0x%lx Pad 0x%lx swipe %d\n",
-                         (unsigned long) thr, (unsigned long) PL_curpad, po));
+    DEBUG_X(PerlIO_printf(Perl_debug_log,
+                         "0x%"UVxf" Pad 0x%"UVxf" swipe %"IVdf"\n",
+                         PTR2UV(thr), PTR2UV(PL_curpad), (IV)po));
 #else
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%lx swipe %d\n",
-                         (unsigned long) PL_curpad, po));
+    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%"UVxf" swipe %"IVdf"\n",
+                         PTR2UV(PL_curpad), (IV)po));
 #endif /* USE_THREADS */
     SvPADTMP_off(PL_curpad[po]);
     PL_curpad[po] = NEWSV(1107,0);
@@ -538,11 +571,12 @@ Perl_pad_reset(pTHX)
     if (AvARRAY(PL_comppad) != PL_curpad)
        Perl_croak(aTHX_ "panic: pad_reset curpad");
 #ifdef USE_THREADS
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "0x%lx Pad 0x%lx reset\n",
-                         (unsigned long) thr, (unsigned long) PL_curpad));
+    DEBUG_X(PerlIO_printf(Perl_debug_log,
+                         "0x%"UVxf" Pad 0x%"UVxf" reset\n",
+                         PTR2UV(thr), PTR2UV(PL_curpad)));
 #else
-    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%lx reset\n",
-                         (unsigned long) PL_curpad));
+    DEBUG_X(PerlIO_printf(Perl_debug_log, "Pad 0x%"UVxf" reset\n",
+                         PTR2UV(PL_curpad)));
 #endif /* USE_THREADS */
     if (!PL_tainting) {        /* Can't mix tainted and non-tainted temporaries. */
        for (po = AvMAX(PL_comppad); po > PL_padix_floor; po--) {
@@ -634,6 +668,26 @@ Perl_op_free(pTHX_ OP *o)
     if (!o || o->op_seq == (U16)-1)
        return;
 
+    if (o->op_private & OPpREFCOUNTED) {
+       switch (o->op_type) {
+       case OP_LEAVESUB:
+       case OP_LEAVESUBLV:
+       case OP_LEAVEEVAL:
+       case OP_LEAVE:
+       case OP_SCOPE:
+       case OP_LEAVEWRITE:
+           OP_REFCNT_LOCK;
+           if (OpREFCNT_dec(o)) {
+               OP_REFCNT_UNLOCK;
+               return;
+           }
+           OP_REFCNT_UNLOCK;
+           break;
+       default:
+           break;
+       }
+    }
+
     if (o->op_flags & OPf_KIDS) {
        for (kid = cUNOPo->op_first; kid; kid = nextkid) {
            nextkid = kid->op_sibling; /* Get before next freeing kid */
@@ -685,8 +739,21 @@ S_op_clear(pTHX_ OP *o)
     case OP_GVSV:
     case OP_GV:
     case OP_AELEMFAST:
-       SvREFCNT_dec(cGVOPo->op_gv);
-       cGVOPo->op_gv = Nullgv;
+#ifdef USE_ITHREADS
+       if (cPADOPo->op_padix > 0) {
+           if (PL_curpad) {
+               GV *gv = cGVOPo_gv;
+               pad_swipe(cPADOPo->op_padix);
+               /* No GvIN_PAD_off(gv) here, because other references may still
+                * exist on the pad */
+               SvREFCNT_dec(gv);
+           }
+           cPADOPo->op_padix = 0;
+       }
+#else
+       SvREFCNT_dec(cSVOPo->op_sv);
+       cSVOPo->op_sv = Nullsv;
+#endif
        break;
     case OP_CONST:
        SvREFCNT_dec(cSVOPo->op_sv);
@@ -711,25 +778,48 @@ S_op_clear(pTHX_ OP *o)
        break;
     case OP_SUBST:
        op_free(cPMOPo->op_pmreplroot);
-       cPMOPo->op_pmreplroot = Nullop;
-       /* FALL THROUGH */
+       goto clear_pmop;
     case OP_PUSHRE:
+#ifdef USE_ITHREADS
+       if ((PADOFFSET)cPMOPo->op_pmreplroot) {
+           if (PL_curpad) {
+               GV *gv = (GV*)PL_curpad[(PADOFFSET)cPMOPo->op_pmreplroot];
+               pad_swipe((PADOFFSET)cPMOPo->op_pmreplroot);
+               /* No GvIN_PAD_off(gv) here, because other references may still
+                * exist on the pad */
+               SvREFCNT_dec(gv);
+           }
+       }
+#else
+       SvREFCNT_dec((SV*)cPMOPo->op_pmreplroot);
+#endif
+       /* FALL THROUGH */
     case OP_MATCH:
     case OP_QR:
+clear_pmop:
+       cPMOPo->op_pmreplroot = Nullop;
        ReREFCNT_dec(cPMOPo->op_pmregexp);
        cPMOPo->op_pmregexp = (REGEXP*)NULL;
        break;
     }
 
-    if (o->op_targ > 0)
+    if (o->op_targ > 0) {
        pad_free(o->op_targ);
+       o->op_targ = 0;
+    }
 }
 
 STATIC void
 S_cop_free(pTHX_ COP* cop)
 {
     Safefree(cop->cop_label);
-    SvREFCNT_dec(cop->cop_filegv);
+#ifdef USE_ITHREADS
+    Safefree(CopFILE(cop));            /* XXXXX share in a pvtable? */
+    Safefree(CopSTASHPV(cop));         /* XXXXX share in a pvtable? */
+#else
+    /* NOTE: COP.cop_stash is not refcounted */
+    SvREFCNT_dec(CopFILEGV(cop));
+#endif
     if (! specialWARN(cop->cop_warnings))
        SvREFCNT_dec(cop->cop_warnings);
 }
@@ -790,12 +880,12 @@ S_scalarboolean(pTHX_ OP *o)
     if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST) {
        dTHR;
        if (ckWARN(WARN_SYNTAX)) {
-           line_t oldline = PL_curcop->cop_line;
+           line_t oldline = CopLINE(PL_curcop);
 
            if (PL_copline != NOLINE)
-               PL_curcop->cop_line = PL_copline;
+               CopLINE_set(PL_curcop, PL_copline);
            Perl_warner(aTHX_ WARN_SYNTAX, "Found = in conditional, should be ==");
-           PL_curcop->cop_line = oldline;
+           CopLINE_set(PL_curcop, oldline);
        }
     }
     return scalar(o);
@@ -809,12 +899,10 @@ Perl_scalar(pTHX_ OP *o)
     /* assumes no premature commitment */
     if (!o || (o->op_flags & OPf_WANT) || PL_error_count
         || o->op_type == OP_RETURN)
+    {
        return o;
+    }
 
-    if ((o->op_private & OPpTARGET_MY)
-       && (PL_opargs[o->op_type] & OA_TARGLEX)) /* OPp share the meaning */
-       return scalar(o);                       /* As if inside SASSIGN */
-    
     o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_SCALAR;
 
     switch (o->op_type) {
@@ -895,11 +983,15 @@ Perl_scalarvoid(pTHX_ OP *o)
     want = o->op_flags & OPf_WANT;
     if ((want && want != OPf_WANT_SCALAR) || PL_error_count
         || o->op_type == OP_RETURN)
+    {
        return o;
+    }
 
     if ((o->op_private & OPpTARGET_MY)
-       && (PL_opargs[o->op_type] & OA_TARGLEX)) /* OPp share the meaning */
+       && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
+    {
        return scalar(o);                       /* As if inside SASSIGN */
+    }
     
     o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_VOID;
 
@@ -992,13 +1084,13 @@ Perl_scalarvoid(pTHX_ OP *o)
     case OP_RV2SV:
     case OP_RV2AV:
     case OP_RV2HV:
-       if (!(o->op_private & OPpLVAL_INTRO) &&
+       if (!(o->op_private & (OPpLVAL_INTRO|OPpOUR_INTRO)) &&
                (!o->op_sibling || o->op_sibling->op_type != OP_READLINE))
            useless = "a variable";
        break;
 
     case OP_CONST:
-       sv = cSVOPo->op_sv;
+       sv = cSVOPo_sv;
        if (cSVOPo->op_private & OPpCONST_STRICT)
            no_bareword_allowed(o);
        else {
@@ -1097,11 +1189,15 @@ Perl_list(pTHX_ OP *o)
     /* assumes no premature commitment */
     if (!o || (o->op_flags & OPf_WANT) || PL_error_count
         || o->op_type == OP_RETURN)
+    {
        return o;
+    }
 
     if ((o->op_private & OPpTARGET_MY)
-       && (PL_opargs[o->op_type] & OA_TARGLEX)) /* OPp share the meaning */
+       && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
+    {
        return o;                               /* As if inside SASSIGN */
+    }
     
     o->op_flags = (o->op_flags & ~OPf_WANT) | OPf_WANT_LIST;
 
@@ -1211,8 +1307,10 @@ Perl_mod(pTHX_ OP *o, I32 type)
        return o;
 
     if ((o->op_private & OPpTARGET_MY)
-       && (PL_opargs[o->op_type] & OA_TARGLEX)) /* OPp share the meaning */
+       && (PL_opargs[o->op_type] & OA_TARGLEX))/* OPp share the meaning */
+    {
        return o;
+    }
     
     switch (o->op_type) {
     case OP_UNDEF:
@@ -1222,7 +1320,7 @@ Perl_mod(pTHX_ OP *o, I32 type)
        if (!(o->op_private & (OPpCONST_ARYBASE)))
            goto nomod;
        if (PL_eval_start && PL_eval_start->op_type == OP_CONST) {
-           PL_compiling.cop_arybase = (I32)SvIV(((SVOP*)PL_eval_start)->op_sv);
+           PL_compiling.cop_arybase = (I32)SvIV(cSVOPx(PL_eval_start)->op_sv);
            PL_eval_start = 0;
        }
        else if (!type) {
@@ -1249,7 +1347,7 @@ Perl_mod(pTHX_ OP *o, I32 type)
        }
        else {                          /* lvalue subroutine call */
            o->op_private |= OPpLVAL_INTRO;
-           if (type == OP_GREPSTART || type == OP_ENTERSUB) {
+           if (type == OP_GREPSTART || type == OP_ENTERSUB || type == OP_REFGEN) {
                /* Backward compatibility mode: */
                o->op_private |= OPpENTERSUB_INARGS;
                break;
@@ -1325,7 +1423,7 @@ Perl_mod(pTHX_ OP *o, I32 type)
                    break;
                }
                
-               cv = GvCV(kGVOP->op_gv);
+               cv = GvCV(kGVOP_gv);
                if (!cv) 
                    goto restore_2cv;
                if (CvLVALUE(cv))
@@ -1593,7 +1691,7 @@ Perl_ref(pTHX_ OP *o, I32 type)
 
     switch (o->op_type) {
     case OP_ENTERSUB:
-       if ((type == OP_DEFINED || type == OP_LOCK) &&
+       if ((type == OP_EXISTS || type == OP_DEFINED || type == OP_LOCK) &&
            !(o->op_flags & OPf_STACKED)) {
            o->op_type = OP_RV2CV;             /* entersub => rv2cv */
            o->op_ppaddr = PL_ppaddr[OP_RV2CV];
@@ -1742,6 +1840,7 @@ S_my_kid(pTHX_ OP *o, OP *attrs)
     } else if (type == OP_RV2SV ||     /* "our" declaration */
               type == OP_RV2AV ||
               type == OP_RV2HV) { /* XXX does this let anything illegal in? */
+       o->op_private |= OPpOUR_INTRO;
        return o;
     } else if (type != OP_PADSV &&
             type != OP_PADAV &&
@@ -1810,9 +1909,9 @@ Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
       char *desc = PL_op_desc[(right->op_type == OP_SUBST ||
                             right->op_type == OP_TRANS)
                            ? right->op_type : OP_MATCH];
-      char *sample = ((left->op_type == OP_RV2AV ||
-                       left->op_type == OP_PADAV)
-                      ? "@array" : "%hash");
+      const char *sample = ((left->op_type == OP_RV2AV ||
+                            left->op_type == OP_PADAV)
+                           ? "@array" : "%hash");
       Perl_warner(aTHX_ WARN_UNSAFE,
              "Applying %s to %s will act on scalar(%s)", 
              desc, sample, sample);
@@ -1861,10 +1960,8 @@ Perl_scope(pTHX_ OP *o)
                o->op_type = OP_SCOPE;
                o->op_ppaddr = PL_ppaddr[OP_SCOPE];
                kid = ((LISTOP*)o)->op_first;
-               if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE){
-                   kid->op_type = OP_SETSTATE;
-                   kid->op_ppaddr = PL_ppaddr[OP_SETSTATE];
-               }
+               if (kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE)
+                   null(kid);
            }
            else
                o = newLISTOP(OP_SCOPE, 0, o, Nullop);
@@ -1904,7 +2001,7 @@ Perl_block_start(pTHX_ int full)
     PL_pad_reset_pending = FALSE;
     SAVEHINTS();
     PL_hints &= ~HINT_BLOCK_SCOPE;
-    SAVEPPTR(PL_compiling.cop_warnings); 
+    SAVESPTR(PL_compiling.cop_warnings); 
     if (! specialWARN(PL_compiling.cop_warnings)) {
         PL_compiling.cop_warnings = newSVsv(PL_compiling.cop_warnings) ;
         SAVEFREESV(PL_compiling.cop_warnings) ;
@@ -1953,6 +2050,8 @@ Perl_newPROG(pTHX_ OP *o)
                               ((PL_in_eval & EVAL_KEEPERR)
                                ? OPf_SPECIAL : 0), o);
        PL_eval_start = linklist(PL_eval_root);
+       PL_eval_root->op_private |= OPpREFCOUNTED;
+       OpREFCNT_set(PL_eval_root, 1);
        PL_eval_root->op_next = 0;
        peep(PL_eval_start);
     }
@@ -1962,6 +2061,8 @@ Perl_newPROG(pTHX_ OP *o)
        PL_main_root = scope(sawparens(scalarvoid(o)));
        PL_curcop = &PL_compiling;
        PL_main_start = LINKLIST(PL_main_root);
+       PL_main_root->op_private |= OPpREFCOUNTED;
+       OpREFCNT_set(PL_main_root, 1);
        PL_main_root->op_next = 0;
        peep(PL_main_start);
        PL_compcv = 0;
@@ -1972,7 +2073,7 @@ Perl_newPROG(pTHX_ OP *o)
            if (cv) {
                dSP;
                PUSHMARK(SP);
-               XPUSHs((SV*)PL_compiling.cop_filegv);
+               XPUSHs((SV*)CopFILEGV(&PL_compiling));
                PUTBACK;
                call_sv((SV*)cv, G_DISCARD);
            }
@@ -2114,8 +2215,12 @@ Perl_fold_constants(pTHX_ register OP *o)
        return o;
 
     if (!(PL_hints & HINT_INTEGER)) {
-       if (type == OP_DIVIDE || !(o->op_flags & OPf_KIDS))
+       if (type == OP_MODULO
+           || type == OP_DIVIDE
+           || !(o->op_flags & OPf_KIDS))
+       {
            return o;
+       }
 
        for (curop = ((UNOP*)o)->op_first; curop; curop = curop->op_sibling) {
            if (curop->op_type == OP_CONST) {
@@ -2146,6 +2251,7 @@ Perl_gen_constant_list(pTHX_ register OP *o)
 
     PL_op = curop = LINKLIST(o);
     o->op_next = 0;
+    peep(curop);
     pp_pushmark();
     CALLRUNOPS(aTHX);
     PL_op = curop;
@@ -2752,8 +2858,8 @@ Perl_pmruntime(pTHX_ OP *o, OP *expr, OP *repl)
        OP *curop;
        if (pm->op_pmflags & PMf_EVAL) {
            curop = 0;
-           if (PL_curcop->cop_line < PL_multi_end)
-               PL_curcop->cop_line = PL_multi_end;
+           if (CopLINE(PL_curcop) < PL_multi_end)
+               CopLINE_set(PL_curcop, PL_multi_end);
        }
 #ifdef USE_THREADS
        else if (repl->op_type == OP_THREADSV
@@ -2777,7 +2883,7 @@ Perl_pmruntime(pTHX_ OP *o, OP *expr, OP *repl)
                    }
 #else
                    if (curop->op_type == OP_GV) {
-                       GV *gv = ((GVOP*)curop)->op_gv;
+                       GV *gv = cGVOPx_gv(curop);
                        repl_has_vars = 1;
                        if (strchr("&`'123456789+", *GvENAME(gv)))
                            break;
@@ -2858,21 +2964,35 @@ Perl_newSVOP(pTHX_ I32 type, I32 flags, SV *sv)
 }
 
 OP *
+Perl_newPADOP(pTHX_ I32 type, I32 flags, SV *sv)
+{
+    PADOP *padop;
+    NewOp(1101, padop, 1, PADOP);
+    padop->op_type = type;
+    padop->op_ppaddr = PL_ppaddr[type];
+    padop->op_padix = pad_alloc(type, SVs_PADTMP);
+    SvREFCNT_dec(PL_curpad[padop->op_padix]);
+    PL_curpad[padop->op_padix] = sv;
+    SvPADTMP_on(sv);
+    padop->op_next = (OP*)padop;
+    padop->op_flags = flags;
+    if (PL_opargs[type] & OA_RETSCALAR)
+       scalar((OP*)padop);
+    if (PL_opargs[type] & OA_TARGET)
+       padop->op_targ = pad_alloc(type, SVs_PADTMP);
+    return CHECKOP(type, padop);
+}
+
+OP *
 Perl_newGVOP(pTHX_ I32 type, I32 flags, GV *gv)
 {
     dTHR;
-    GVOP *gvop;
-    NewOp(1101, gvop, 1, GVOP);
-    gvop->op_type = type;
-    gvop->op_ppaddr = PL_ppaddr[type];
-    gvop->op_gv = (GV*)SvREFCNT_inc(gv);
-    gvop->op_next = (OP*)gvop;
-    gvop->op_flags = flags;
-    if (PL_opargs[type] & OA_RETSCALAR)
-       scalar((OP*)gvop);
-    if (PL_opargs[type] & OA_TARGET)
-       gvop->op_targ = pad_alloc(type, SVs_PADTMP);
-    return CHECKOP(type, gvop);
+#ifdef USE_ITHREADS
+    GvIN_PAD_on(gv);
+    return newPADOP(type, flags, SvREFCNT_inc(gv));
+#else
+    return newSVOP(type, flags, SvREFCNT_inc(gv));
+#endif
 }
 
 OP *
@@ -3001,6 +3121,7 @@ Perl_utilize(pTHX_ int aver, I32 floor, OP *version, OP *id, OP *arg)
                newSTATEOP(0, Nullch, veop)),
            newSTATEOP(0, Nullch, imop) ));
 
+    PL_hints |= HINT_BLOCK_SCOPE;
     PL_copline = NOLINE;
     PL_expect = XSTATE;
 }
@@ -3110,7 +3231,7 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
            for (curop = LINKLIST(o); curop != o; curop = LINKLIST(curop)) {
                if (PL_opargs[curop->op_type] & OA_DANGEROUS) {
                    if (curop->op_type == OP_GV) {
-                       GV *gv = ((GVOP*)curop)->op_gv;
+                       GV *gv = cGVOPx_gv(curop);
                        if (gv == PL_defgv || SvCUR(gv) == PL_generation)
                            break;
                        SvCUR(gv) = PL_generation;
@@ -3162,7 +3283,13 @@ Perl_newASSIGNOP(pTHX_ I32 flags, OP *left, I32 optype, OP *right)
                {
                    tmpop = ((UNOP*)left)->op_first;
                    if (tmpop->op_type == OP_GV && !pm->op_pmreplroot) {
-                       pm->op_pmreplroot = (OP*)((GVOP*)tmpop)->op_gv;
+#ifdef USE_ITHREADS
+                       pm->op_pmreplroot = (OP*)cPADOPx(tmpop)->op_padix;
+                       cPADOPx(tmpop)->op_padix = 0;   /* steal it */
+#else
+                       pm->op_pmreplroot = (OP*)cSVOPx(tmpop)->op_sv;
+                       cSVOPx(tmpop)->op_sv = Nullsv;  /* steal it */
+#endif
                        pm->op_pmflags |= PMf_ONCE;
                        tmpop = cUNOPo->op_first;       /* to list (nulled) */
                        tmpop = ((UNOP*)tmpop)->op_first; /* to pushmark */
@@ -3215,7 +3342,7 @@ Perl_newSTATEOP(pTHX_ I32 flags, char *label, OP *o)
     register COP *cop;
 
     NewOp(1101, cop, 1, COP);
-    if (PERLDB_LINE && PL_curcop->cop_line && PL_curstash != PL_debstash) {
+    if (PERLDB_LINE && CopLINE(PL_curcop) && PL_curstash != PL_debstash) {
        cop->op_type = OP_DBSTATE;
        cop->op_ppaddr = PL_ppaddr[ OP_DBSTATE ];
     }
@@ -3244,20 +3371,23 @@ Perl_newSTATEOP(pTHX_ I32 flags, char *label, OP *o)
 
 
     if (PL_copline == NOLINE)
-        cop->cop_line = PL_curcop->cop_line;
+        CopLINE_set(cop, CopLINE(PL_curcop));
     else {
-        cop->cop_line = PL_copline;
+       CopLINE_set(cop, PL_copline);
         PL_copline = NOLINE;
     }
-    cop->cop_filegv = (GV*)SvREFCNT_inc(PL_curcop->cop_filegv);
-    cop->cop_stash = PL_curstash;
+#ifdef USE_ITHREADS
+    CopFILE_set(cop, CopFILE(PL_curcop));      /* XXXXX share in a pvtable? */
+#else
+    CopFILEGV_set(cop, (GV*)SvREFCNT_inc(CopFILEGV(PL_curcop)));
+#endif
+    CopSTASH_set(cop, PL_curstash);
 
     if (PERLDB_LINE && PL_curstash != PL_debstash) {
-       SV **svp = av_fetch(GvAV(PL_curcop->cop_filegv),(I32)cop->cop_line, FALSE);
+       SV **svp = av_fetch(CopFILEAV(PL_curcop), (I32)CopLINE(cop), FALSE);
        if (svp && *svp != &PL_sv_undef && !SvIOK(*svp)) {
            (void)SvIOK_on(*svp);
-           SvIVX(*svp) = 1;
-           SvSTASH(*svp) = (HV*)cop;
+           SvIVX(*svp) = PTR2IV(cop);
        }
     }
 
@@ -3352,25 +3482,31 @@ S_new_logop(pTHX_ I32 type, I32 flags, OP** firstp, OP** otherp)
            if (k2 && k2->op_type == OP_READLINE
                  && (k2->op_flags & OPf_STACKED)
                  && ((k1->op_flags & OPf_WANT) == OPf_WANT_SCALAR)) 
+           {
                warnop = k2->op_type;
+           }
            break;
 
        case OP_SASSIGN:
            if (k1->op_type == OP_READDIR
                  || k1->op_type == OP_GLOB
+                 || (k1->op_type == OP_NULL && k1->op_targ == OP_GLOB)
                  || k1->op_type == OP_EACH)
-               warnop = k1->op_type;
+           {
+               warnop = ((k1->op_type == OP_NULL)
+                         ? k1->op_targ : k1->op_type);
+           }
            break;
        }
        if (warnop) {
-           line_t oldline = PL_curcop->cop_line;
-           PL_curcop->cop_line = PL_copline;
+           line_t oldline = CopLINE(PL_curcop);
+           CopLINE_set(PL_curcop, PL_copline);
            Perl_warner(aTHX_ WARN_UNSAFE,
                 "Value of %s%s can be \"0\"; test with defined()",
                 PL_op_desc[warnop],
                 ((warnop == OP_READLINE || warnop == OP_GLOB)
                  ? " construct" : "() operator"));
-           PL_curcop->cop_line = oldline;
+           CopLINE_set(PL_curcop, oldline);
        }
     }
 
@@ -3531,6 +3667,7 @@ Perl_newLOOPOP(pTHX_ I32 flags, I32 debuggable, OP *expr, OP *block)
              case OP_SASSIGN:
                if (k1->op_type == OP_READDIR
                      || k1->op_type == OP_GLOB
+                     || (k1->op_type == OP_NULL && k1->op_targ == OP_NULL)
                      || k1->op_type == OP_EACH)
                    expr = newUNOP(OP_DEFINED, 0, expr);
                break;
@@ -3584,6 +3721,7 @@ Perl_newWHILEOP(pTHX_ I32 flags, I32 debuggable, LOOP *loop, I32 whileline, OP *
          case OP_SASSIGN:
            if (k1->op_type == OP_READDIR
                  || k1->op_type == OP_GLOB
+                 || (k1->op_type == OP_NULL && k1->op_targ == OP_GLOB)
                  || k1->op_type == OP_EACH)
                expr = newUNOP(OP_DEFINED, 0, expr);
            break;
@@ -3664,11 +3802,13 @@ Perl_newFOROP(pTHX_ I32 flags,char *label,line_t forline,OP *sv,OP *expr,OP *blo
        }
        else if (sv->op_type == OP_PADSV) { /* private variable */
            padoff = sv->op_targ;
+           sv->op_targ = 0;
            op_free(sv);
            sv = Nullop;
        }
        else if (sv->op_type == OP_THREADSV) { /* per-thread variable */
            padoff = sv->op_targ;
+           sv->op_targ = 0;
            iterflags |= OPf_SPECIAL;
            op_free(sv);
            sv = Nullop;
@@ -3786,7 +3926,7 @@ Perl_cv_undef(pTHX_ CV *cv)
 #endif /* USE_THREADS */
        ENTER;
 
-       SAVESPTR(PL_curpad);
+       SAVEVPTR(PL_curpad);
        PL_curpad = 0;
 
        if (!CvCLONED(cv))
@@ -3823,10 +3963,10 @@ Perl_cv_undef(pTHX_ CV *cv)
     }
 }
 
-#ifdef DEBUG_CLOSURES
 STATIC void
-cv_dump(CV *cv)
+S_cv_dump(pTHX_ CV *cv)
 {
+#ifdef DEBUGGING
     CV *outside = CvOUTSIDE(cv);
     AV* padlist = CvPADLIST(cv);
     AV* pad_name;
@@ -3835,13 +3975,14 @@ cv_dump(CV *cv)
     SV** ppad;
     I32 ix;
 
-    PerlIO_printf(Perl_debug_log, "\tCV=0x%lx (%s), OUTSIDE=0x%lx (%s)\n",
-                 cv,
+    PerlIO_printf(Perl_debug_log,
+                 "\tCV=0x%"UVxf" (%s), OUTSIDE=0x%"UVxf" (%s)\n",
+                 PTR2UV(cv),
                  (CvANON(cv) ? "ANON"
                   : (cv == PL_main_cv) ? "MAIN"
                   : CvUNIQUE(cv) ? "UNIQUE"
                   : CvGV(cv) ? GvNAME(CvGV(cv)) : "UNDEFINED"),
-                 outside,
+                 PTR2UV(outside),
                  (!outside ? "null"
                   : CvANON(outside) ? "ANON"
                   : (outside == PL_main_cv) ? "MAIN"
@@ -3858,15 +3999,16 @@ cv_dump(CV *cv)
 
     for (ix = 1; ix <= AvFILLp(pad_name); ix++) {
        if (SvPOK(pname[ix]))
-           PerlIO_printf(Perl_debug_log, "\t%4d. 0x%lx (%s\"%s\" %ld-%ld)\n",
-                         ix, ppad[ix],
+           PerlIO_printf(Perl_debug_log,
+                         "\t%4d. 0x%"UVxf" (%s\"%s\" %"IVdf"-%"IVdf")\n",
+                         ix, PTR2UV(ppad[ix]),
                          SvFAKE(pname[ix]) ? "FAKE " : "",
                          SvPVX(pname[ix]),
-                         (long)I_32(SvNVX(pname[ix])),
-                         (long)SvIVX(pname[ix]));
+                         (IV)I_32(SvNVX(pname[ix])),
+                         SvIVX(pname[ix]));
     }
+#endif /* DEBUGGING */
 }
-#endif /* DEBUG_CLOSURES */
 
 STATIC CV *
 S_cv_clone2(pTHX_ CV *proto, CV *outside)
@@ -3887,7 +4029,7 @@ S_cv_clone2(pTHX_ CV *proto, CV *outside)
     assert(!CvUNIQUE(proto));
 
     ENTER;
-    SAVESPTR(PL_curpad);
+    SAVEVPTR(PL_curpad);
     SAVESPTR(PL_comppad);
     SAVESPTR(PL_comppad_name);
     SAVESPTR(PL_compcv);
@@ -3903,7 +4045,7 @@ S_cv_clone2(pTHX_ CV *proto, CV *outside)
     MUTEX_INIT(CvMUTEXP(cv));
     CvOWNER(cv)                = 0;
 #endif /* USE_THREADS */
-    CvFILEGV(cv)       = CvFILEGV(proto);
+    CvFILE(cv)         = CvFILE(proto);
     CvGV(cv)           = (GV*)SvREFCNT_inc(CvGV(proto));
     CvSTASH(cv)                = CvSTASH(proto);
     CvROOT(cv)         = CvROOT(proto);
@@ -3962,6 +4104,9 @@ S_cv_clone2(pTHX_ CV *proto, CV *outside)
                PL_curpad[ix] = sv;
            }
        }
+       else if (IS_PADGV(ppad[ix]) || IS_PADCONST(ppad[ix])) {
+           PL_curpad[ix] = SvREFCNT_inc(ppad[ix]);
+       }
        else {
            SV* sv = NEWSV(0,0);
            SvPADTMP_on(sv);
@@ -4004,9 +4149,9 @@ CV *
 Perl_cv_clone(pTHX_ CV *proto)
 {
     CV *cv;
-    MUTEX_LOCK(&PL_cred_mutex);                /* XXX create separate mutex */
+    LOCK_CRED_MUTEX;                   /* XXX create separate mutex */
     cv = cv_clone2(proto, CvOUTSIDE(proto));
-    MUTEX_UNLOCK(&PL_cred_mutex);      /* XXX create separate mutex */
+    UNLOCK_CRED_MUTEX;                 /* XXX create separate mutex */
     return cv;
 }
 
@@ -4065,9 +4210,9 @@ Perl_op_const_sv(pTHX_ OP *o, CV *cv)
            break;
        if (sv)
            return Nullsv;
-       if (type == OP_CONST)
+       if (type == OP_CONST && cSVOPo->op_sv)
            sv = cSVOPo->op_sv;
-       else if (type == OP_PADSV && cv) {
+       else if ((type == OP_PADSV || type == OP_CONST) && cv) {
            AV* padav = (AV*)(AvARRAY(CvPADLIST(cv))[1]);
            sv = padav ? AvARRAY(padav)[o->op_targ] : Nullsv;
            if (!sv || (!SvREADONLY(sv) && SvREFCNT(sv) > 1))
@@ -4166,12 +4311,12 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
                                        && HvNAME(GvSTASH(CvGV(cv)))
                                        && strEQ(HvNAME(GvSTASH(CvGV(cv))),
                                                 "autouse"))) {
-               line_t oldline = PL_curcop->cop_line;
-               PL_curcop->cop_line = PL_copline;
+               line_t oldline = CopLINE(PL_curcop);
+               CopLINE_set(PL_curcop, PL_copline);
                Perl_warner(aTHX_ WARN_REDEFINE,
                        const_sv ? "Constant subroutine %s redefined"
                                 : "Subroutine %s redefined", name);
-               PL_curcop->cop_line = oldline;
+               CopLINE_set(PL_curcop, oldline);
            }
            SvREFCNT_dec(cv);
            cv = Nullcv;
@@ -4229,7 +4374,7 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
        }
     }
     CvGV(cv) = (GV*)SvREFCNT_inc(gv);
-    CvFILEGV(cv) = PL_curcop->cop_filegv;
+    CvFILE(cv) = CopFILE(PL_curcop);
     CvSTASH(cv) = PL_curstash;
 #ifdef USE_THREADS
     CvOWNER(cv) = 0;
@@ -4271,12 +4416,25 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
     if (AvFILLp(PL_comppad_name) < AvFILLp(PL_comppad))
        av_store(PL_comppad_name, AvFILLp(PL_comppad), Nullsv);
 
+    if (CvLVALUE(cv)) {
+       CvROOT(cv) = newUNOP(OP_LEAVESUBLV, 0, scalarseq(block));
+    }
+    else {
+       CvROOT(cv) = newUNOP(OP_LEAVESUB, 0, scalarseq(block));
+    }
+    CvROOT(cv)->op_private |= OPpREFCOUNTED;
+    OpREFCNT_set(CvROOT(cv), 1);
+    CvSTART(cv) = LINKLIST(CvROOT(cv));
+    CvROOT(cv)->op_next = 0;
+    peep(CvSTART(cv));
+
+    /* now that optimizer has done its work, adjust pad values */
     if (CvCLONE(cv)) {
        SV **namep = AvARRAY(PL_comppad_name);
        for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
            SV *namesv;
 
-           if (SvIMMORTAL(PL_curpad[ix]))
+           if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
                continue;
            /*
             * The only things that a clonable function needs in its
@@ -4300,23 +4458,13 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
        AvFLAGS(av) = AVf_REIFY;
 
        for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
-           if (SvIMMORTAL(PL_curpad[ix]))
+           if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
                continue;
            if (!SvPADMY(PL_curpad[ix]))
                SvPADTMP_on(PL_curpad[ix]);
        }
     }
 
-    if(CvLVALUE(cv)) {
-       CvROOT(cv) = newUNOP(OP_LEAVESUBLV, 0, scalarseq(block));
-    }
-    else {
-       CvROOT(cv) = newUNOP(OP_LEAVESUB, 0, scalarseq(block));
-    }
-    CvSTART(cv) = LINKLIST(CvROOT(cv));
-    CvROOT(cv)->op_next = 0;
-    peep(CvSTART(cv));
-
     if (name) {
        char *s;
 
@@ -4327,9 +4475,9 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
            CV *cv;
            HV *hv;
 
-           Perl_sv_setpvf(aTHX_ sv, "%_:%ld-%ld",
-                   GvSV(PL_curcop->cop_filegv),
-                   (long)PL_subline, (long)PL_curcop->cop_line);
+           Perl_sv_setpvf(aTHX_ sv, "%s:%ld-%ld",
+                          CopFILE(PL_curcop),
+                          (long)PL_subline, (long)CopLINE(PL_curcop));
            gv_efullname3(tmpstr, gv, Nullch);
            hv_store(GvHV(PL_DBsub), SvPVX(tmpstr), SvCUR(tmpstr), sv, 0);
            hv = GvHVn(db_postponed);
@@ -4347,18 +4495,22 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
            s++;
        else
            s = name;
+
+       if (*s != 'B' && *s != 'E' && *s != 'S' && *s != 'I')
+           goto done;
+
        if (strEQ(s, "BEGIN")) {
            I32 oldscope = PL_scopestack_ix;
            ENTER;
-           SAVESPTR(PL_compiling.cop_filegv);
-           SAVEI16(PL_compiling.cop_line);
+           SAVECOPFILE(&PL_compiling);
+           SAVECOPLINE(&PL_compiling);
            save_svref(&PL_rs);
            sv_setsv(PL_rs, PL_nrs);
 
            if (!PL_beginav)
                PL_beginav = newAV();
            DEBUG_x( dump_sub(gv) );
-           av_push(PL_beginav, (SV *)cv);
+           av_push(PL_beginav, SvREFCNT_inc(cv));
            GvCV(gv) = 0;
            call_list(oldscope, PL_beginav);
 
@@ -4369,13 +4521,23 @@ Perl_newATTRSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
        else if (strEQ(s, "END") && !PL_error_count) {
            if (!PL_endav)
                PL_endav = newAV();
+           DEBUG_x( dump_sub(gv) );
            av_unshift(PL_endav, 1);
-           av_store(PL_endav, 0, (SV *)cv);
+           av_store(PL_endav, 0, SvREFCNT_inc(cv));
+           GvCV(gv) = 0;
+       }
+       else if (strEQ(s, "STOP") && !PL_error_count) {
+           if (!PL_stopav)
+               PL_stopav = newAV();
+           DEBUG_x( dump_sub(gv) );
+           av_unshift(PL_stopav, 1);
+           av_store(PL_stopav, 0, SvREFCNT_inc(cv));
            GvCV(gv) = 0;
        }
        else if (strEQ(s, "INIT") && !PL_error_count) {
            if (!PL_initav)
                PL_initav = newAV();
+           DEBUG_x( dump_sub(gv) );
            av_push(PL_initav, SvREFCNT_inc(cv));
            GvCV(gv) = 0;
        }
@@ -4392,15 +4554,24 @@ void
 Perl_newCONSTSUB(pTHX_ HV *stash, char *name, SV *sv)
 {
     dTHR;
-    U32 oldhints = PL_hints;
-    HV *old_cop_stash = PL_curcop->cop_stash;
-    HV *old_curstash = PL_curstash;
-    line_t oldline = PL_curcop->cop_line;
-    PL_curcop->cop_line = PL_copline;
 
+    ENTER;
+    SAVECOPLINE(PL_curcop);
+    SAVEHINTS();
+
+    CopLINE_set(PL_curcop, PL_copline);
     PL_hints &= ~HINT_BLOCK_SCOPE;
-    if(stash)
-       PL_curstash = PL_curcop->cop_stash = stash;
+
+    if (stash) {
+       SAVESPTR(PL_curstash);
+       SAVECOPSTASH(PL_curcop);
+       PL_curstash = stash;
+#ifdef USE_ITHREADS
+       CopSTASHPV(PL_curcop) = stash ? HvNAME(stash) : Nullch;
+#else
+       CopSTASH(PL_curcop) = stash;
+#endif
+    }
 
     newATTRSUB(
        start_subparse(FALSE, 0),
@@ -4410,10 +4581,7 @@ Perl_newCONSTSUB(pTHX_ HV *stash, char *name, SV *sv)
        newSTATEOP(0, Nullch, newSVOP(OP_CONST, 0, sv))
     );
 
-    PL_hints = oldhints;
-    PL_curcop->cop_stash = old_cop_stash;
-    PL_curstash = old_curstash;
-    PL_curcop->cop_line = oldline;
+    LEAVE;
 }
 
 CV *
@@ -4434,11 +4602,11 @@ Perl_newXS(pTHX_ char *name, XSUBADDR_t subaddr, char *filename)
            if (ckWARN(WARN_REDEFINE) && !(CvGV(cv) && GvSTASH(CvGV(cv))
                            && HvNAME(GvSTASH(CvGV(cv)))
                            && strEQ(HvNAME(GvSTASH(CvGV(cv))), "autouse"))) {
-               line_t oldline = PL_curcop->cop_line;
+               line_t oldline = CopLINE(PL_curcop);
                if (PL_copline != NOLINE)
-                   PL_curcop->cop_line = PL_copline;
+                   CopLINE_set(PL_curcop, PL_copline);
                Perl_warner(aTHX_ WARN_REDEFINE, "Subroutine %s redefined",name);
-               PL_curcop->cop_line = oldline;
+               CopLINE_set(PL_curcop, oldline);
            }
            SvREFCNT_dec(cv);
            cv = 0;
@@ -4462,7 +4630,9 @@ Perl_newXS(pTHX_ char *name, XSUBADDR_t subaddr, char *filename)
     MUTEX_INIT(CvMUTEXP(cv));
     CvOWNER(cv) = 0;
 #endif /* USE_THREADS */
-    CvFILEGV(cv) = gv_fetchfile(filename);
+    (void)gv_fetchfile(filename);
+    CvFILE(cv) = filename;     /* NOTE: not copied, as it is expected to be
+                                  an external constant string */
     CvXSUB(cv) = subaddr;
 
     if (name) {
@@ -4471,29 +4641,41 @@ Perl_newXS(pTHX_ char *name, XSUBADDR_t subaddr, char *filename)
            s++;
        else
            s = name;
+
+       if (*s != 'B' && *s != 'E' && *s != 'S' && *s != 'I')
+           goto done;
+
        if (strEQ(s, "BEGIN")) {
            if (!PL_beginav)
                PL_beginav = newAV();
-           av_push(PL_beginav, (SV *)cv);
+           av_push(PL_beginav, SvREFCNT_inc(cv));
            GvCV(gv) = 0;
        }
        else if (strEQ(s, "END")) {
            if (!PL_endav)
                PL_endav = newAV();
            av_unshift(PL_endav, 1);
-           av_store(PL_endav, 0, (SV *)cv);
+           av_store(PL_endav, 0, SvREFCNT_inc(cv));
+           GvCV(gv) = 0;
+       }
+       else if (strEQ(s, "STOP")) {
+           if (!PL_stopav)
+               PL_stopav = newAV();
+           av_unshift(PL_stopav, 1);
+           av_store(PL_stopav, 0, SvREFCNT_inc(cv));
            GvCV(gv) = 0;
        }
        else if (strEQ(s, "INIT")) {
            if (!PL_initav)
                PL_initav = newAV();
-           av_push(PL_initav, (SV *)cv);
+           av_push(PL_initav, SvREFCNT_inc(cv));
            GvCV(gv) = 0;
        }
     }
     else
        CvANON_on(cv);
 
+done:
     return cv;
 }
 
@@ -4515,18 +4697,18 @@ Perl_newFORM(pTHX_ I32 floor, OP *o, OP *block)
     GvMULTI_on(gv);
     if (cv = GvFORM(gv)) {
        if (ckWARN(WARN_REDEFINE)) {
-           line_t oldline = PL_curcop->cop_line;
+           line_t oldline = CopLINE(PL_curcop);
 
-           PL_curcop->cop_line = PL_copline;
+           CopLINE_set(PL_curcop, PL_copline);
            Perl_warner(aTHX_ WARN_REDEFINE, "Format %s redefined",name);
-           PL_curcop->cop_line = oldline;
+           CopLINE_set(PL_curcop, oldline);
        }
        SvREFCNT_dec(cv);
     }
     cv = PL_compcv;
     GvFORM(gv) = cv;
     CvGV(cv) = (GV*)SvREFCNT_inc(gv);
-    CvFILEGV(cv) = PL_curcop->cop_filegv;
+    CvFILE(cv) = CopFILE(PL_curcop);
 
     for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
        if (!SvPADMY(PL_curpad[ix]) && !SvIMMORTAL(PL_curpad[ix]))
@@ -4534,6 +4716,8 @@ Perl_newFORM(pTHX_ I32 floor, OP *o, OP *block)
     }
 
     CvROOT(cv) = newUNOP(OP_LEAVEWRITE, 0, scalarseq(block));
+    CvROOT(cv)->op_private |= OPpREFCOUNTED;
+    OpREFCNT_set(CvROOT(cv), 1);
     CvSTART(cv) = LINKLIST(CvROOT(cv));
     CvROOT(cv)->op_next = 0;
     peep(CvSTART(cv));
@@ -4748,11 +4932,22 @@ Perl_ck_delete(pTHX_ OP *o)
     o->op_private = 0;
     if (o->op_flags & OPf_KIDS) {
        OP *kid = cUNOPo->op_first;
-       if (kid->op_type == OP_HSLICE)
+       switch (kid->op_type) {
+       case OP_ASLICE:
+           o->op_flags |= OPf_SPECIAL;
+           /* FALL THROUGH */
+       case OP_HSLICE:
            o->op_private |= OPpSLICE;
-       else if (kid->op_type != OP_HELEM)
-           Perl_croak(aTHX_ "%s argument is not a HASH element or slice",
+           break;
+       case OP_AELEM:
+           o->op_flags |= OPf_SPECIAL;
+           /* FALL THROUGH */
+       case OP_HELEM:
+           break;
+       default:
+           Perl_croak(aTHX_ "%s argument is not a HASH or ARRAY element or slice",
                  PL_op_desc[o->op_type]);
+       }
        null(kid);
     }
     return o;
@@ -4838,8 +5033,18 @@ Perl_ck_exists(pTHX_ OP *o)
     o = ck_fun(o);
     if (o->op_flags & OPf_KIDS) {
        OP *kid = cUNOPo->op_first;
-       if (kid->op_type != OP_HELEM)
-           Perl_croak(aTHX_ "%s argument is not a HASH element", PL_op_desc[o->op_type]);
+       if (kid->op_type == OP_ENTERSUB) {
+           (void) ref(kid, o->op_type);
+           if (kid->op_type != OP_RV2CV && !PL_error_count)
+               Perl_croak(aTHX_ "%s argument is not a subroutine name",
+                          PL_op_desc[o->op_type]);
+           o->op_private |= OPpEXISTS_SUB;
+       }
+       else if (kid->op_type == OP_AELEM)
+           o->op_flags |= OPf_SPECIAL;
+       else if (kid->op_type != OP_HELEM)
+           Perl_croak(aTHX_ "%s argument is not a HASH or ARRAY element",
+                      PL_op_desc[o->op_type]);
        null(kid);
     }
     return o;
@@ -4951,7 +5156,14 @@ Perl_ck_rvconst(pTHX_ register OP *o)
        if (gv) {
            kid->op_type = OP_GV;
            SvREFCNT_dec(kid->op_sv);
+#ifdef USE_ITHREADS
+           /* XXX hack: dependence on sizeof(PADOP) <= sizeof(SVOP) */
+           kPADOP->op_padix = pad_alloc(OP_GV, SVs_PADTMP);
+           GvIN_PAD_on(gv);
+           PL_curpad[kPADOP->op_padix] = SvREFCNT_inc(gv);
+#else
            kid->op_sv = SvREFCNT_inc(gv);
+#endif
            kid->op_ppaddr = PL_ppaddr[OP_GV];
        }
     }
@@ -4964,10 +5176,10 @@ Perl_ck_ftst(pTHX_ OP *o)
     dTHR;
     I32 type = o->op_type;
 
-    if (o->op_flags & OPf_REF)
-       return o;
-
-    if (o->op_flags & OPf_KIDS && cUNOPo->op_first->op_type != OP_STUB) {
+    if (o->op_flags & OPf_REF) {
+       /* nothing */
+    }
+    else if (o->op_flags & OPf_KIDS && cUNOPo->op_first->op_type != OP_STUB) {
        SVOP *kid = (SVOP*)cUNOPo->op_first;
 
        if (kid->op_type == OP_CONST && (kid->op_private & OPpCONST_BARE)) {
@@ -4975,17 +5187,24 @@ Perl_ck_ftst(pTHX_ OP *o)
            OP *newop = newGVOP(type, OPf_REF,
                gv_fetchpv(SvPVx(kid->op_sv, n_a), TRUE, SVt_PVIO));
            op_free(o);
-           return newop;
+           o = newop;
        }
     }
     else {
        op_free(o);
        if (type == OP_FTTTY)
-           return newGVOP(type, OPf_REF, gv_fetchpv("main::STDIN", TRUE,
+           o =  newGVOP(type, OPf_REF, gv_fetchpv("main::STDIN", TRUE,
                                SVt_PVIO));
        else
-           return newUNOP(type, 0, newDEFSVOP());
+           o = newUNOP(type, 0, newDEFSVOP());
     }
+#ifdef USE_LOCALE
+    if (type == OP_FTTEXT || type == OP_FTBINARY) {
+       o->op_private = 0;
+       if (PL_hints & HINT_LOCALE)
+           o->op_private |= OPpLOCALE;
+    }
+#endif
     return o;
 }
 
@@ -5110,26 +5329,46 @@ Perl_ck_fun(pTHX_ OP *o)
                    else {
                        I32 flags = OPf_SPECIAL;
                        I32 priv = 0;
+                       PADOFFSET targ = 0;
+
                        /* is this op a FH constructor? */
                        if (is_handle_constructor(o,numargs)) {
-                           flags   = 0;                         
-                           /* Set a flag to tell rv2gv to vivify 
+                           char *name = Nullch;
+                           STRLEN len;
+
+                           flags = 0;
+                           /* Set a flag to tell rv2gv to vivify
                             * need to "prove" flag does not mean something
                             * else already - NI-S 1999/05/07
-                            */ 
-                           priv = OPpDEREF; 
-#if 0
-                           /* Helps with open($array[$n],...) 
-                              but is too simplistic - need to do selectively
-                           */
-                           mod(kid,type);
-#endif
+                            */
+                           priv = OPpDEREF;
+                           if (kid->op_type == OP_PADSV) {
+                               SV **namep = av_fetch(PL_comppad_name,
+                                                     kid->op_targ, 4);
+                               if (namep && *namep)
+                                   name = SvPV(*namep, len);
+                           }
+                           else if (kid->op_type == OP_RV2SV
+                                    && kUNOP->op_first->op_type == OP_GV)
+                           {
+                               GV *gv = cGVOPx_gv(kUNOP->op_first);
+                               name = GvNAME(gv);
+                               len = GvNAMELEN(gv);
+                           }
+                           if (name) {
+                               SV *namesv;
+                               targ = pad_alloc(OP_RV2GV, SVs_PADTMP);
+                               namesv = PL_curpad[targ];
+                               SvUPGRADE(namesv, SVt_PV);
+                               if (*name != '$')
+                                   sv_setpvn(namesv, "$", 1);
+                               sv_catpvn(namesv, name, len);
+                           }
                        }
                        kid->op_sibling = 0;
                        kid = newUNOP(OP_RV2GV, flags, scalar(kid));
-                       if (priv) {
-                           kid->op_private |= priv;
-                       }
+                       kid->op_targ = targ;
+                       kid->op_private |= priv;
                    }
                    kid->op_sibling = sibl;
                    *tokid = kid;
@@ -5174,6 +5413,19 @@ Perl_ck_glob(pTHX_ OP *o)
     if (!((gv = gv_fetchpv("glob", FALSE, SVt_PVCV)) && GvIMPORTED_CV(gv)))
        gv = gv_fetchpv("CORE::GLOBAL::glob", FALSE, SVt_PVCV);
 
+#if !defined(PERL_EXTERNAL_GLOB)
+    /* XXX this can be tightened up and made more failsafe. */
+    if (!gv) {
+       OP *modname = newSVOP(OP_CONST, 0, newSVpvn("File::Glob", 10));
+       modname->op_private |= OPpCONST_BARE;
+       ENTER;
+       utilize(1, start_subparse(FALSE, 0), Nullop, modname,
+               newSVOP(OP_CONST, 0, newSVpvn(":globally", 9)));
+       gv = gv_fetchpv("CORE::GLOBAL::glob", FALSE, SVt_PVCV);
+       LEAVE;
+    }
+#endif /* PERL_EXTERNAL_GLOB */
+
     if (gv && GvIMPORTED_CV(gv)) {
        append_elem(OP_GLOB, o,
                    newSVOP(OP_CONST, 0, newSViv(PL_glob_index++)));
@@ -5378,32 +5630,8 @@ Perl_ck_sassign(pTHX_ OP *o)
        if (kkid && kkid->op_type == OP_PADSV
            && !(kkid->op_private & OPpLVAL_INTRO))
        {
-           /* Concat has problems if target is equal to right arg. */
-           if (kid->op_type == OP_CONCAT) {
-               if (kLISTOP->op_first->op_sibling->op_type == OP_PADSV
-                   && kLISTOP->op_first->op_sibling->op_targ == kkid->op_targ)
-                   return o;
-           }
-           else if (kid->op_type == OP_JOIN) {
-               /* do_join has problems if the arguments coincide with target.
-                  In fact the second argument *can* safely coincide,
-                  but ignore=pessimize this rare occasion. */
-               OP *arg = kLISTOP->op_first->op_sibling; /* Skip PUSHMARK */
-
-               while (arg) {
-                   if (arg->op_type == OP_PADSV
-                       && arg->op_targ == kkid->op_targ)
-                       return o;
-                   arg = arg->op_sibling;
-               }
-           }
-           else if (kid->op_type == OP_QUOTEMETA) {
-               /* quotemeta has problems if the argument coincides with target. */
-               if (kLISTOP->op_first->op_type == OP_PADSV
-                   && kLISTOP->op_first->op_targ == kkid->op_targ)
-                   return o;
-           }
            kid->op_targ = kkid->op_targ;
+           kkid->op_targ = 0;
            /* Now we do not need PADSV and SASSIGN. */
            kid->op_sibling = o->op_sibling;    /* NULL */
            cLISTOPo->op_first = NULL;
@@ -5612,6 +5840,7 @@ S_simplify_sort(pTHX_ OP *o)
     register OP *kid = cLISTOPo->op_first->op_sibling; /* get past pushmark */
     OP *k;
     int reversed;
+    GV *gv;
     if (!(o->op_flags & OPf_STACKED))
        return;
     GvMULTI_on(gv_fetchpv("a", TRUE, SVt_PV)); 
@@ -5635,11 +5864,12 @@ S_simplify_sort(pTHX_ OP *o)
     if (kUNOP->op_first->op_type != OP_GV)
        return;
     kid = kUNOP->op_first;                             /* get past rv2sv */
-    if (GvSTASH(kGVOP->op_gv) != PL_curstash)
+    gv = kGVOP_gv;
+    if (GvSTASH(gv) != PL_curstash)
        return;
-    if (strEQ(GvNAME(kGVOP->op_gv), "a"))
+    if (strEQ(GvNAME(gv), "a"))
        reversed = 0;
-    else if(strEQ(GvNAME(kGVOP->op_gv), "b"))
+    else if(strEQ(GvNAME(gv), "b"))
        reversed = 1;
     else
        return;
@@ -5650,10 +5880,11 @@ S_simplify_sort(pTHX_ OP *o)
     if (kUNOP->op_first->op_type != OP_GV)
        return;
     kid = kUNOP->op_first;                             /* get past rv2sv */
-    if (GvSTASH(kGVOP->op_gv) != PL_curstash
+    gv = kGVOP_gv;
+    if (GvSTASH(gv) != PL_curstash
        || ( reversed
-           ? strNE(GvNAME(kGVOP->op_gv), "a")
-           : strNE(GvNAME(kGVOP->op_gv), "b")))
+           ? strNE(GvNAME(gv), "a")
+           : strNE(GvNAME(gv), "b")))
        return;
     o->op_flags &= ~(OPf_STACKED | OPf_SPECIAL);
     if (reversed)
@@ -5759,11 +5990,12 @@ Perl_ck_subr(pTHX_ OP *o)
        null(cvop);             /* disable rv2cv */
        tmpop = (SVOP*)((UNOP*)cvop)->op_first;
        if (tmpop->op_type == OP_GV && !(o->op_private & OPpENTERSUB_AMPER)) {
-           cv = GvCVu(tmpop->op_sv);
+           GV *gv = cGVOPx_gv(tmpop);
+           cv = GvCVu(gv);
            if (!cv)
                tmpop->op_private |= OPpEARLY_CV;
            else if (SvPOK(cv)) {
-               namegv = CvANON(cv) ? (GV*)tmpop->op_sv : CvGV(cv);
+               namegv = CvANON(cv) ? gv : CvGV(cv);
                proto = SvPV((SV*)cv, n_a);
            }
        }
@@ -5826,7 +6058,7 @@ Perl_ck_subr(pTHX_ OP *o)
                                (gvop = ((UNOP*)gvop)->op_first) &&
                                gvop->op_type == OP_GV)
                            {
-                               GV *gv = (GV*)((SVOP*)gvop)->op_sv;
+                               GV *gv = cGVOPx_gv(gvop);
                                OP *sibling = o2->op_sibling;
                                SV *n = newSVpvn("",0);
                                op_free(o2);
@@ -5944,7 +6176,7 @@ Perl_peep(pTHX_ register OP *o)
        return;
     ENTER;
     SAVEOP();
-    SAVESPTR(PL_curcop);
+    SAVEVPTR(PL_curcop);
     for (; o; o = o->op_next) {
        if (o->op_seq)
            break;
@@ -5963,32 +6195,34 @@ Perl_peep(pTHX_ register OP *o)
        case OP_CONST:
            if (cSVOPo->op_private & OPpCONST_STRICT)
                no_bareword_allowed(o);
+#ifdef USE_ITHREADS
+           /* Relocate sv to the pad for thread safety.
+            * Despite being a "constant", the SV is written to,
+            * for reference counts, sv_upgrade() etc. */
+           if (cSVOP->op_sv) {
+               PADOFFSET ix = pad_alloc(OP_CONST, SVs_PADTMP);
+               SvREFCNT_dec(PL_curpad[ix]);
+               SvPADTMP_on(cSVOPo->op_sv);
+               PL_curpad[ix] = cSVOPo->op_sv;
+               cSVOPo->op_sv = Nullsv;
+               o->op_targ = ix;
+           }
+#endif
            /* FALL THROUGH */
        case OP_UC:
        case OP_UCFIRST:
        case OP_LC:
        case OP_LCFIRST:
-           if ( o->op_next && o->op_next->op_type == OP_STRINGIFY
-                && !(o->op_next->op_private & OPpTARGET_MY) )
-               null(o->op_next);
-           o->op_seq = PL_op_seqmax++;
-           break;
        case OP_CONCAT:
        case OP_JOIN:
        case OP_QUOTEMETA:
            if (o->op_next && o->op_next->op_type == OP_STRINGIFY) {
                if (o->op_next->op_private & OPpTARGET_MY) {
-                   if ((o->op_flags & OPf_STACKED) /* chained concats */
-                       || (o->op_type == OP_CONCAT
-           /* Concat has problems if target is equal to right arg. */
-                           && (((LISTOP*)o)->op_first->op_sibling->op_type
-                               == OP_PADSV)
-                           && (((LISTOP*)o)->op_first->op_sibling->op_targ
-                               == o->op_next->op_targ))) {
+                   if (o->op_flags & OPf_STACKED) /* chained concats */
                        goto ignore_optimization;
-                   }
                    else {
                        o->op_targ = o->op_next->op_targ;
+                       o->op_next->op_targ = 0;
                        o->op_private |= OPpTARGET_MY;
                    }
                }
@@ -6044,6 +6278,7 @@ Perl_peep(pTHX_ register OP *o)
                                <= 255 &&
                    i >= 0)
                {
+                   GV *gv;
                    null(o->op_next);
                    null(pop->op_next);
                    null(pop);
@@ -6052,11 +6287,12 @@ Perl_peep(pTHX_ register OP *o)
                    o->op_type = OP_AELEMFAST;
                    o->op_ppaddr = PL_ppaddr[OP_AELEMFAST];
                    o->op_private = (U8)i;
-                   GvAVn(((GVOP*)o)->op_gv);
+                   gv = cGVOPo_gv;
+                   GvAVn(gv);
                }
            }
            else if ((o->op_private & OPpEARLY_CV) && ckWARN(WARN_UNSAFE)) {
-               GV *gv = cGVOPo->op_gv;
+               GV *gv = cGVOPo_gv;
                if (SvTYPE(gv) == SVt_PVGV && GvCV(gv) && SvPVX(GvCV(gv))) {
                    /* XXX could check prototype here instead of just carping */
                    SV *sv = sv_newmortal();
@@ -6106,12 +6342,12 @@ Perl_peep(pTHX_ register OP *o)
                        o->op_next->op_sibling->op_type != OP_EXIT &&
                        o->op_next->op_sibling->op_type != OP_WARN &&
                        o->op_next->op_sibling->op_type != OP_DIE) {
-                   line_t oldline = PL_curcop->cop_line;
+                   line_t oldline = CopLINE(PL_curcop);
 
-                   PL_curcop->cop_line = ((COP*)o->op_next)->cop_line;
+                   CopLINE_set(PL_curcop, CopLINE((COP*)o->op_next));
                    Perl_warner(aTHX_ WARN_SYNTAX, "Statement unlikely to be reached");
                    Perl_warner(aTHX_ WARN_SYNTAX, "(Maybe you meant system() when you said exec()?)\n");
-                   PL_curcop->cop_line = oldline;
+                   CopLINE_set(PL_curcop, oldline);
                }
            }
            break;
@@ -6137,7 +6373,7 @@ Perl_peep(pTHX_ register OP *o)
            fields = (GV**)hv_fetch(SvSTASH(lexname), "FIELDS", 6, FALSE);
            if (!fields || !GvHV(*fields))
                break;
-           svp = &((SVOP*)((BINOP*)o)->op_last)->op_sv;
+           svp = cSVOPx_svp(((BINOP*)o)->op_last);
            key = SvPV(*svp, keylen);
            indsvp = hv_fetch(GvHV(*fields), key, keylen, FALSE);
            if (!indsvp) {
@@ -6159,13 +6395,15 @@ Perl_peep(pTHX_ register OP *o)
        case OP_RV2AV:
        case OP_RV2HV:
            if (!(o->op_flags & OPf_WANT)
-               || o->op_flags & OPf_WANT == OPf_WANT_LIST)
+               || (o->op_flags & OPf_WANT) == OPf_WANT_LIST)
+           {
                last_composite = o;
+           }
            o->op_seq = PL_op_seqmax++;
            break;
 
        case OP_RETURN:
-           if (o->op_next->op_type != OP_LEAVESUBLV) {
+           if (o->op_next && o->op_next->op_type != OP_LEAVESUBLV) {
                o->op_seq = PL_op_seqmax++;
                break;
            }