Refactor IPC::Open3::_open3() to find the caller's package itself.

[perl5.git] / pad.c

diff --git a/pad.c b/pad.c
index 715d361..ff52eb8 100644 (file)
--- a/pad.c
+++ b/pad.c
@@ -78,7 +78,17 @@ in PL_op->op_targ), wasting a name SV for them doesn't make sense.
 
 The SVs in the names AV have their PV being the name of the variable.
 xlow+1..xhigh inclusive in the NV union is a range of cop_seq numbers for
 
 The SVs in the names AV have their PV being the name of the variable.
 xlow+1..xhigh inclusive in the NV union is a range of cop_seq numbers for

-which the name is valid.  For typed lexicals name SV is SVt_PVMG and SvSTASH
+which the name is valid (accessed through the macros COP_SEQ_RANGE_LOW and
+_HIGH).  During compilation, these fields may hold the special value
+PERL_PADSEQ_INTRO to indicate various stages:
+
+   COP_SEQ_RANGE_LOW        _HIGH
+   -----------------        -----
+   PERL_PADSEQ_INTRO            0   variable not yet introduced:   { my ($x
+   valid-seq#   PERL_PADSEQ_INTRO   variable in scope:             { my ($x)
+   valid-seq#          valid-seq#   compilation of scope complete: { my ($x) }
+
+For typed lexicals name SV is SVt_PVMG and SvSTASH

 points at the type.  For C<our> lexicals, the type is also SVt_PVMG, with the
 SvOURSTASH slot pointing at the stash of the associated global (so that
 duplicate C<our> declarations in the same package can be detected).  SvUVX is
 points at the type.  For C<our> lexicals, the type is also SVt_PVMG, with the
 SvOURSTASH slot pointing at the stash of the associated global (so that
 duplicate C<our> declarations in the same package can be detected).  SvUVX is


@@ -101,13 +111,13 @@ become so if C<my sub foo {}> is implemented.)
 Note that formats are treated as anon subs, and are cloned each time
 write is called (if necessary).
 
 Note that formats are treated as anon subs, and are cloned each time
 write is called (if necessary).
 

-The flag SVf_PADSTALE is cleared on lexicals each time the my() is executed,
+The flag SVs_PADSTALE is cleared on lexicals each time the my() is executed,

 and set on scope exit. This allows the 'Variable $x is not available' warning
 to be generated in evals, such as 
 
     { my $x = 1; sub f { eval '$x'} } f();
 
 and set on scope exit. This allows the 'Variable $x is not available' warning
 to be generated in evals, such as 
 
     { my $x = 1; sub f { eval '$x'} } f();
 

-For state vars, SVf_PADSTALE is overloaded to mean 'not yet initialised'
+For state vars, SVs_PADSTALE is overloaded to mean 'not yet initialised'

 
 =cut
 */
 
 =cut
 */


@@ -128,11 +138,10 @@ For state vars, SVf_PADSTALE is overloaded to mean 'not yet initialised'
 #define PARENT_FAKELEX_FLAGS_set(sv,val)       \
   STMT_START { ((XPVNV*)SvANY(sv))->xnv_u.xpad_cop_seq.xhigh = (val); } STMT_END
 
 #define PARENT_FAKELEX_FLAGS_set(sv,val)       \
   STMT_START { ((XPVNV*)SvANY(sv))->xnv_u.xpad_cop_seq.xhigh = (val); } STMT_END
 

-#define PAD_MAX I32_MAX
-

 #ifdef PERL_MAD
 void pad_peg(const char* s) {
 #ifdef PERL_MAD
 void pad_peg(const char* s) {

-    static int pegcnt;
+    static int pegcnt; /* XXX not threadsafe */
+    PERL_UNUSED_ARG(s);

 
     PERL_ARGS_ASSERT_PAD_PEG;
 
 
     PERL_ARGS_ASSERT_PAD_PEG;
 


@@ -159,6 +168,7 @@ Perl_pad_new(pTHX_ int flags)
 {
     dVAR;
     AV *padlist, *padname, *pad;
 {
     dVAR;
     AV *padlist, *padname, *pad;

+    SV **ary;

 
     ASSERT_CURPAD_LEGAL("pad_new");
 
 
     ASSERT_CURPAD_LEGAL("pad_new");
 


@@ -200,7 +210,6 @@ Perl_pad_new(pTHX_ int flags)
         */
 
         AV * const a0 = newAV();                       /* will be @_ */
         */
 
         AV * const a0 = newAV();                       /* will be @_ */

-       av_extend(a0, 0);

        av_store(pad, 0, MUTABLE_SV(a0));
        AvREIFY_only(a0);
     }
        av_store(pad, 0, MUTABLE_SV(a0));
        AvREIFY_only(a0);
     }


@@ -209,14 +218,23 @@ Perl_pad_new(pTHX_ int flags)
     }
 
     AvREAL_off(padlist);
     }
 
     AvREAL_off(padlist);

-    av_store(padlist, 0, MUTABLE_SV(padname));
-    av_store(padlist, 1, MUTABLE_SV(pad));
+    /* Most subroutines never recurse, hence only need 2 entries in the padlist
+       array - names, and depth=1.  The default for av_store() is to allocate
+       0..3, and even an explicit call to av_extend() with <3 will be rounded
+       up, so we inline the allocation of the array here.  */
+    Newx(ary, 2, SV*);
+    AvFILLp(padlist) = 1;
+    AvMAX(padlist) = 1;
+    AvALLOC(padlist) = ary;
+    AvARRAY(padlist) = ary;
+    ary[0] = MUTABLE_SV(padname);
+    ary[1] = MUTABLE_SV(pad);

 
     /* ... then update state variables */
 
 
     /* ... then update state variables */
 

-    PL_comppad_name    = MUTABLE_AV((*av_fetch(padlist, 0, FALSE)));
-    PL_comppad         = MUTABLE_AV((*av_fetch(padlist, 1, FALSE)));
-    PL_curpad          = AvARRAY(PL_comppad);
+    PL_comppad_name    = padname;
+    PL_comppad         = pad;
+    PL_curpad          = AvARRAY(pad);

 
     if (! (flags & padnew_CLONE)) {
        PL_comppad_name_fill = 0;
 
     if (! (flags & padnew_CLONE)) {
        PL_comppad_name_fill = 0;


@@ -236,108 +254,190 @@ Perl_pad_new(pTHX_ int flags)
     return (PADLIST*)padlist;
 }
 
     return (PADLIST*)padlist;
 }
 

+

 /*
 /*

-=for apidoc pad_undef
+=head1 Embedding Functions

 
 

-Free the padlist associated with a CV.
-If parts of it happen to be current, we null the relevant
-PL_*pad* global vars so that we don't have any dangling references left.
-We also repoint the CvOUTSIDE of any about-to-be-orphaned
-inner subs to the outer of this cv.
+=for apidoc cv_undef

 
 

-(This function should really be called pad_free, but the name was already
-taken)
+Clear out all the active components of a CV. This can happen either
+by an explicit C<undef &foo>, or by the reference count going to zero.
+In the former case, we keep the CvOUTSIDE pointer, so that any anonymous
+children can still follow the full lexical scope chain.

 
 =cut
 */
 
 void
 
 =cut
 */
 
 void

-Perl_pad_undef(pTHX_ CV* cv)
+Perl_cv_undef(pTHX_ CV *cv)

 {
     dVAR;
 {
     dVAR;

-    I32 ix;
-    const PADLIST * const padlist = CvPADLIST(cv);
+    const PADLIST *padlist = CvPADLIST(cv);

 
 

-    PERL_ARGS_ASSERT_PAD_UNDEF;
-
-    pad_peg("pad_undef");
-    if (!padlist)
-       return;
-    if (SvIS_FREED(padlist)) /* may be during global destruction */
-       return;
+    PERL_ARGS_ASSERT_CV_UNDEF;

 
     DEBUG_X(PerlIO_printf(Perl_debug_log,
 
     DEBUG_X(PerlIO_printf(Perl_debug_log,

-         "Pad undef: cv=0x%"UVxf" padlist=0x%"UVxf" comppad=0x%"UVxf"\n",
-           PTR2UV(cv), PTR2UV(padlist), PTR2UV(PL_comppad))
+         "CV undef: cv=0x%"UVxf" comppad=0x%"UVxf"\n",
+           PTR2UV(cv), PTR2UV(PL_comppad))

     );
 
     );
 

-    /* detach any '&' anon children in the pad; if afterwards they
-     * are still live, fix up their CvOUTSIDEs to point to our outside,
-     * bypassing us. */
-    /* XXX DAPM for efficiency, we should only do this if we know we have
-     * children, or integrate this loop with general cleanup */
-
-    if (!PL_dirty) { /* don't bother during global destruction */
-       CV * const outercv = CvOUTSIDE(cv);
-        const U32 seq = CvOUTSIDE_SEQ(cv);
-       AV *  const comppad_name = MUTABLE_AV(AvARRAY(padlist)[0]);
-       SV ** const namepad = AvARRAY(comppad_name);
-       AV *  const comppad = MUTABLE_AV(AvARRAY(padlist)[1]);
-       SV ** const curpad = AvARRAY(comppad);
-       for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
-           SV * const namesv = namepad[ix];
-           if (namesv && namesv != &PL_sv_undef
-               && *SvPVX_const(namesv) == '&')
-           {
-               CV * const innercv = MUTABLE_CV(curpad[ix]);
-               U32 inner_rc = SvREFCNT(innercv);
-               assert(inner_rc);
-               namepad[ix] = NULL;
-               SvREFCNT_dec(namesv);
-
-               if (SvREFCNT(comppad) < 2) { /* allow for /(?{ sub{} })/  */
-                   curpad[ix] = NULL;
-                   SvREFCNT_dec(innercv);
-                   inner_rc--;
-               }
+#ifdef USE_ITHREADS
+    if (CvFILE(cv) && !CvISXSUB(cv)) {
+       /* for XSUBs CvFILE point directly to static memory; __FILE__ */
+       Safefree(CvFILE(cv));
+    }
+    CvFILE(cv) = NULL;
+#endif

 
 

-               /* in use, not just a prototype */
-               if (inner_rc && (CvOUTSIDE(innercv) == cv)) {
-                   assert(CvWEAKOUTSIDE(innercv));
-                   /* don't relink to grandfather if he's being freed */
-                   if (outercv && SvREFCNT(outercv)) {
-                       CvWEAKOUTSIDE_off(innercv);
-                       CvOUTSIDE(innercv) = outercv;
-                       CvOUTSIDE_SEQ(innercv) = seq;
-                       SvREFCNT_inc_simple_void_NN(outercv);
-                   }
-                   else {
-                       CvOUTSIDE(innercv) = NULL;
+    if (!CvISXSUB(cv) && CvROOT(cv)) {
+       if (SvTYPE(cv) == SVt_PVCV && CvDEPTH(cv))
+           Perl_croak(aTHX_ "Can't undef active subroutine");
+       ENTER;
+
+       PAD_SAVE_SETNULLPAD();
+
+       op_free(CvROOT(cv));
+       CvROOT(cv) = NULL;
+       CvSTART(cv) = NULL;
+       LEAVE;
+    }
+    SvPOK_off(MUTABLE_SV(cv));         /* forget prototype */
+    CvGV_set(cv, NULL);
+
+    /* This statement and the subsequence if block was pad_undef().  */
+    pad_peg("pad_undef");
+
+    if (padlist && !SvIS_FREED(padlist) /* may be during global destruction */
+       ) {
+       I32 ix;
+
+       /* Free the padlist associated with a CV.
+          If parts of it happen to be current, we null the relevant PL_*pad*
+          global vars so that we don't have any dangling references left.
+          We also repoint the CvOUTSIDE of any about-to-be-orphaned inner
+          subs to the outer of this cv.  */
+
+       DEBUG_X(PerlIO_printf(Perl_debug_log,
+                             "Pad undef: cv=0x%"UVxf" padlist=0x%"UVxf" comppad=0x%"UVxf"\n",
+                             PTR2UV(cv), PTR2UV(padlist), PTR2UV(PL_comppad))
+               );
+
+       /* detach any '&' anon children in the pad; if afterwards they
+        * are still live, fix up their CvOUTSIDEs to point to our outside,
+        * bypassing us. */
+       /* XXX DAPM for efficiency, we should only do this if we know we have
+        * children, or integrate this loop with general cleanup */
+
+       if (PL_phase != PERL_PHASE_DESTRUCT) { /* don't bother during global destruction */
+           CV * const outercv = CvOUTSIDE(cv);
+           const U32 seq = CvOUTSIDE_SEQ(cv);
+           AV *  const comppad_name = MUTABLE_AV(AvARRAY(padlist)[0]);
+           SV ** const namepad = AvARRAY(comppad_name);
+           AV *  const comppad = MUTABLE_AV(AvARRAY(padlist)[1]);
+           SV ** const curpad = AvARRAY(comppad);
+           for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
+               SV * const namesv = namepad[ix];
+               if (namesv && namesv != &PL_sv_undef
+                   && *SvPVX_const(namesv) == '&')
+                   {
+                       CV * const innercv = MUTABLE_CV(curpad[ix]);
+                       U32 inner_rc = SvREFCNT(innercv);
+                       assert(inner_rc);
+                       namepad[ix] = NULL;
+                       SvREFCNT_dec(namesv);
+
+                       if (SvREFCNT(comppad) < 2) { /* allow for /(?{ sub{} })/  */
+                           curpad[ix] = NULL;
+                           SvREFCNT_dec(innercv);
+                           inner_rc--;
+                       }
+
+                       /* in use, not just a prototype */
+                       if (inner_rc && (CvOUTSIDE(innercv) == cv)) {
+                           assert(CvWEAKOUTSIDE(innercv));
+                           /* don't relink to grandfather if he's being freed */
+                           if (outercv && SvREFCNT(outercv)) {
+                               CvWEAKOUTSIDE_off(innercv);
+                               CvOUTSIDE(innercv) = outercv;
+                               CvOUTSIDE_SEQ(innercv) = seq;
+                               SvREFCNT_inc_simple_void_NN(outercv);
+                           }
+                           else {
+                               CvOUTSIDE(innercv) = NULL;
+                           }
+                       }

                    }
                    }

-               }

            }
        }
            }
        }

-    }

 
 

-    ix = AvFILLp(padlist);
-    while (ix >= 0) {
-       SV* const sv = AvARRAY(padlist)[ix--];
-       if (sv) {
+       ix = AvFILLp(padlist);
+       while (ix > 0) {
+           SV* const sv = AvARRAY(padlist)[ix--];
+           if (sv) {
+               if (sv == (const SV *)PL_comppad) {
+                   PL_comppad = NULL;
+                   PL_curpad = NULL;
+               }
+               SvREFCNT_dec(sv);
+           }
+       }
+       {
+           SV *const sv = AvARRAY(padlist)[0];

            if (sv == (const SV *)PL_comppad_name)
                PL_comppad_name = NULL;
            if (sv == (const SV *)PL_comppad_name)
                PL_comppad_name = NULL;

-           else if (sv == (const SV *)PL_comppad) {
-               PL_comppad = NULL;
-               PL_curpad = NULL;
-           }
+           SvREFCNT_dec(sv);

        }
        }

-       SvREFCNT_dec(sv);
+       SvREFCNT_dec(MUTABLE_SV(CvPADLIST(cv)));
+       CvPADLIST(cv) = NULL;
+    }
+
+
+    /* remove CvOUTSIDE unless this is an undef rather than a free */
+    if (!SvREFCNT(cv) && CvOUTSIDE(cv)) {
+       if (!CvWEAKOUTSIDE(cv))
+           SvREFCNT_dec(CvOUTSIDE(cv));
+       CvOUTSIDE(cv) = NULL;
+    }
+    if (CvCONST(cv)) {
+       SvREFCNT_dec(MUTABLE_SV(CvXSUBANY(cv).any_ptr));
+       CvCONST_off(cv);

     }
     }

-    SvREFCNT_dec(MUTABLE_SV(CvPADLIST(cv)));
-    CvPADLIST(cv) = NULL;
+    if (CvISXSUB(cv) && CvXSUB(cv)) {
+       CvXSUB(cv) = NULL;
+    }
+    /* delete all flags except WEAKOUTSIDE and CVGV_RC, which indicate the
+     * ref status of CvOUTSIDE and CvGV */
+    CvFLAGS(cv) &= (CVf_WEAKOUTSIDE|CVf_CVGV_RC);

 }
 
 }
 

+static PADOFFSET
+S_pad_add_name_sv(pTHX_ SV *namesv, const U32 flags, HV *typestash,
+                 HV *ourstash)
+{
+    dVAR;
+    const PADOFFSET offset = pad_alloc(OP_PADSV, SVs_PADMY);
+
+    PERL_ARGS_ASSERT_PAD_ADD_NAME_SV;

 
 

+    ASSERT_CURPAD_ACTIVE("pad_add_name");
+
+    if (typestash) {
+       assert(SvTYPE(namesv) == SVt_PVMG);
+       SvPAD_TYPED_on(namesv);
+       SvSTASH_set(namesv, MUTABLE_HV(SvREFCNT_inc_simple_NN(MUTABLE_SV(typestash))));
+    }
+    if (ourstash) {
+       SvPAD_OUR_on(namesv);
+       SvOURSTASH_set(namesv, ourstash);
+       SvREFCNT_inc_simple_void_NN(ourstash);
+    }
+    else if (flags & padadd_STATE) {
+       SvPAD_STATE_on(namesv);
+    }

 
 

+    av_store(PL_comppad_name, offset, namesv);
+    return offset;
+}

 
 /*
 =for apidoc pad_add_name
 
 /*
 =for apidoc pad_add_name


@@ -355,59 +455,53 @@ If fake, it means we're cloning an existing entry
 */
 
 PADOFFSET
 */
 
 PADOFFSET

-Perl_pad_add_name(pTHX_ const char *name, HV* typestash, HV* ourstash, bool fake, bool state)
+Perl_pad_add_name(pTHX_ const char *name, const STRLEN len, const U32 flags,
+                 HV *typestash, HV *ourstash)

 {
     dVAR;
 {
     dVAR;

-    const PADOFFSET offset = pad_alloc(OP_PADSV, SVs_PADMY);
-    SV* const namesv
-       = newSV_type((ourstash || typestash) ? SVt_PVMG : SVt_PVNV);
+    PADOFFSET offset;
+    SV *namesv;

 
     PERL_ARGS_ASSERT_PAD_ADD_NAME;
 
 
     PERL_ARGS_ASSERT_PAD_ADD_NAME;
 

-    ASSERT_CURPAD_ACTIVE("pad_add_name");
+    if (flags & ~(padadd_OUR|padadd_STATE|padadd_NO_DUP_CHECK))
+       Perl_croak(aTHX_ "panic: pad_add_name illegal flag bits 0x%" UVxf,
+                  (UV)flags);
+
+    namesv = newSV_type((ourstash || typestash) ? SVt_PVMG : SVt_PVNV);
+
+    /* Until we're using the length for real, cross check that we're being told
+       the truth.  */
+    PERL_UNUSED_ARG(len);
+    assert(strlen(name) == len);

 
     sv_setpv(namesv, name);
 
 
     sv_setpv(namesv, name);
 

-    if (typestash) {
-       assert(SvTYPE(namesv) == SVt_PVMG);
-       SvPAD_TYPED_on(namesv);
-       SvSTASH_set(namesv, MUTABLE_HV(SvREFCNT_inc_simple_NN(MUTABLE_SV(typestash))));
-    }
-    if (ourstash) {
-       SvPAD_OUR_on(namesv);
-       SvOURSTASH_set(namesv, ourstash);
-       SvREFCNT_inc_simple_void_NN(ourstash);
-    }
-    else if (state) {
-       SvPAD_STATE_on(namesv);
+    if ((flags & padadd_NO_DUP_CHECK) == 0) {
+       /* check for duplicate declaration */
+       pad_check_dup(namesv, flags & padadd_OUR, ourstash);

     }
 
     }
 

-    av_store(PL_comppad_name, offset, namesv);
-    if (fake) {
-       SvFAKE_on(namesv);
-       DEBUG_Xv(PerlIO_printf(Perl_debug_log,
-           "Pad addname: %ld \"%s\" FAKE\n", (long)offset, name));
-    }
-    else {
-       /* not yet introduced */
-       COP_SEQ_RANGE_LOW_set(namesv, PAD_MAX); /* min */
-       COP_SEQ_RANGE_HIGH_set(namesv, 0);              /* max */
-
-       if (!PL_min_intro_pending)
-           PL_min_intro_pending = offset;
-       PL_max_intro_pending = offset;
-       /* if it's not a simple scalar, replace with an AV or HV */
-       /* XXX DAPM since slot has been allocated, replace
-        * av_store with PL_curpad[offset] ? */
-       if (*name == '@')
-           av_store(PL_comppad, offset, MUTABLE_SV(newAV()));
-       else if (*name == '%')
-           av_store(PL_comppad, offset, MUTABLE_SV(newHV()));
-       SvPADMY_on(PL_curpad[offset]);
-       DEBUG_Xv(PerlIO_printf(Perl_debug_log,
-           "Pad addname: %ld \"%s\" new lex=0x%"UVxf"\n",
-           (long)offset, name, PTR2UV(PL_curpad[offset])));
-    }
+    offset = pad_add_name_sv(namesv, flags, typestash, ourstash);
+
+    /* not yet introduced */
+    COP_SEQ_RANGE_LOW_set(namesv, PERL_PADSEQ_INTRO);
+    COP_SEQ_RANGE_HIGH_set(namesv, 0);
+
+    if (!PL_min_intro_pending)
+       PL_min_intro_pending = offset;
+    PL_max_intro_pending = offset;
+    /* if it's not a simple scalar, replace with an AV or HV */
+    assert(SvTYPE(PL_curpad[offset]) == SVt_NULL);
+    assert(SvREFCNT(PL_curpad[offset]) == 1);
+    if (*name == '@')
+       sv_upgrade(PL_curpad[offset], SVt_PVAV);
+    else if (*name == '%')
+       sv_upgrade(PL_curpad[offset], SVt_PVHV);
+    assert(SvPADMY(PL_curpad[offset]));
+    DEBUG_Xv(PerlIO_printf(Perl_debug_log,
+                          "Pad addname: %ld \"%s\" new lex=0x%"UVxf"\n",
+                          (long)offset, name, PTR2UV(PL_curpad[offset])));

 
     return offset;
 }
 
     return offset;
 }


@@ -504,9 +598,10 @@ Perl_pad_add_anon(pTHX_ SV* sv, OPCODE op_type)
 
     pad_peg("add_anon");
     sv_setpvs(name, "&");
 
     pad_peg("add_anon");
     sv_setpvs(name, "&");

-    /* Are these two actually ever read? */
-    COP_SEQ_RANGE_HIGH_set(name, ~0);
-    COP_SEQ_RANGE_LOW_set(name, 1);
+    /* These two aren't used; just make sure they're not equal to
+     * PERL_PADSEQ_INTRO */
+    COP_SEQ_RANGE_LOW_set(name, 0);
+    COP_SEQ_RANGE_HIGH_set(name, 0);

     ix = pad_alloc(op_type, SVs_PADMY);
     av_store(PL_comppad_name, ix, name);
     /* XXX DAPM use PL_curpad[] ? */
     ix = pad_alloc(op_type, SVs_PADMY);
     av_store(PL_comppad_name, ix, name);
     /* XXX DAPM use PL_curpad[] ? */


@@ -537,18 +632,20 @@ C<is_our> indicates that the name to check is an 'our' declaration
 =cut
 */
 
 =cut
 */
 

-/* XXX DAPM integrate this into pad_add_name ??? */
-
-void
-Perl_pad_check_dup(pTHX_ const char *name, bool is_our, const HV *ourstash)
+STATIC void
+S_pad_check_dup(pTHX_ SV *name, const U32 flags, const HV *ourstash)

 {
     dVAR;
     SV         **svp;
     PADOFFSET  top, off;
 {
     dVAR;
     SV         **svp;
     PADOFFSET  top, off;

+    const U32  is_our = flags & padadd_OUR;

 
     PERL_ARGS_ASSERT_PAD_CHECK_DUP;
 
     ASSERT_CURPAD_ACTIVE("pad_check_dup");
 
     PERL_ARGS_ASSERT_PAD_CHECK_DUP;
 
     ASSERT_CURPAD_ACTIVE("pad_check_dup");

+
+    assert((flags & ~padadd_OUR) == 0);
+

     if (AvFILLp(PL_comppad_name) < 0 || !ckWARN(WARN_MISC))
        return; /* nothing to check */
 
     if (AvFILLp(PL_comppad_name) < 0 || !ckWARN(WARN_MISC))
        return; /* nothing to check */
 


@@ -562,39 +659,43 @@ Perl_pad_check_dup(pTHX_ const char *name, bool is_our, const HV *ourstash)
        if (sv
            && sv != &PL_sv_undef
            && !SvFAKE(sv)
        if (sv
            && sv != &PL_sv_undef
            && !SvFAKE(sv)

-           && (COP_SEQ_RANGE_HIGH(sv) == PAD_MAX || COP_SEQ_RANGE_HIGH(sv) == 0)
-           && strEQ(name, SvPVX_const(sv)))
+           && (   COP_SEQ_RANGE_LOW(sv)  == PERL_PADSEQ_INTRO
+               || COP_SEQ_RANGE_HIGH(sv) == PERL_PADSEQ_INTRO)
+           && sv_eq(name, sv))

        {
            if (is_our && (SvPAD_OUR(sv)))
                break; /* "our" masking "our" */
            Perl_warner(aTHX_ packWARN(WARN_MISC),
        {
            if (is_our && (SvPAD_OUR(sv)))
                break; /* "our" masking "our" */
            Perl_warner(aTHX_ packWARN(WARN_MISC),

-               "\"%s\" variable %s masks earlier declaration in same %s",
+               "\"%s\" variable %"SVf" masks earlier declaration in same %s",

                (is_our ? "our" : PL_parser->in_my == KEY_my ? "my" : "state"),
                (is_our ? "our" : PL_parser->in_my == KEY_my ? "my" : "state"),

-               name,
-               (COP_SEQ_RANGE_HIGH(sv) == PAD_MAX ? "scope" : "statement"));
+               sv,
+               (COP_SEQ_RANGE_HIGH(sv) == PERL_PADSEQ_INTRO
+                   ? "scope" : "statement"));

            --off;
            break;
        }
     }
     /* check the rest of the pad */
     if (is_our) {
            --off;
            break;
        }
     }
     /* check the rest of the pad */
     if (is_our) {

-       do {
+       while (off > 0) {

            SV * const sv = svp[off];
            if (sv
                && sv != &PL_sv_undef
                && !SvFAKE(sv)
            SV * const sv = svp[off];
            if (sv
                && sv != &PL_sv_undef
                && !SvFAKE(sv)

-               && (COP_SEQ_RANGE_HIGH(sv) == PAD_MAX || COP_SEQ_RANGE_HIGH(sv) == 0)
+               && (   COP_SEQ_RANGE_LOW(sv)  == PERL_PADSEQ_INTRO
+                   || COP_SEQ_RANGE_HIGH(sv) == PERL_PADSEQ_INTRO)

                && SvOURSTASH(sv) == ourstash
                && SvOURSTASH(sv) == ourstash

-               && strEQ(name, SvPVX_const(sv)))
+               && sv_eq(name, sv))

            {
                Perl_warner(aTHX_ packWARN(WARN_MISC),
            {
                Perl_warner(aTHX_ packWARN(WARN_MISC),

-                   "\"our\" variable %s redeclared", name);
+                   "\"our\" variable %"SVf" redeclared", sv);

                if ((I32)off <= PL_comppad_name_floor)
                    Perl_warner(aTHX_ packWARN(WARN_MISC),
                        "\t(Did you mean \"local\" instead of \"our\"?)\n");
                break;
            }
                if ((I32)off <= PL_comppad_name_floor)
                    Perl_warner(aTHX_ packWARN(WARN_MISC),
                        "\t(Did you mean \"local\" instead of \"our\"?)\n");
                break;
            }

-       } while ( off-- > 0 );
+           --off;
+       }

     }
 }
 
     }
 }
 


@@ -612,7 +713,7 @@ Returns the offset in the current pad, or NOT_IN_PAD on failure.
 */
 
 PADOFFSET
 */
 
 PADOFFSET

-Perl_pad_findmy(pTHX_ const char *name)
+Perl_pad_findmy(pTHX_ const char *name, STRLEN len, U32 flags)

 {
     dVAR;
     SV *out_sv;
 {
     dVAR;
     SV *out_sv;


@@ -624,6 +725,22 @@ Perl_pad_findmy(pTHX_ const char *name)
     PERL_ARGS_ASSERT_PAD_FINDMY;
 
     pad_peg("pad_findmy");
     PERL_ARGS_ASSERT_PAD_FINDMY;
 
     pad_peg("pad_findmy");

+
+    if (flags)
+       Perl_croak(aTHX_ "panic: pad_findmy illegal flag bits 0x%" UVxf,
+                  (UV)flags);
+
+    /* Yes, it is a bug (read work in progress) that we're not really using this
+       length parameter, and instead relying on strlen() later on. But I'm not
+       comfortable about changing the pad API piecemeal to use and rely on
+       lengths. This only exists to avoid an "unused parameter" warning.  */
+    if (len < 2) 
+       return NOT_IN_PAD;
+
+    /* But until we're using the length for real, cross check that we're being
+       told the truth.  */
+    assert(strlen(name) == len);
+

     offset = pad_findlex(name, PL_compcv, PL_cop_seqmax, 1,
                NULL, &out_sv, &out_flags);
     if ((PADOFFSET)offset != NOT_IN_PAD) 
     offset = pad_findlex(name, PL_compcv, PL_cop_seqmax, 1,
                NULL, &out_sv, &out_flags);
     if ((PADOFFSET)offset != NOT_IN_PAD) 


@@ -641,7 +758,7 @@ Perl_pad_findmy(pTHX_ const char *name)
            && !SvFAKE(namesv)
            && (SvPAD_OUR(namesv))
            && strEQ(SvPVX_const(namesv), name)
            && !SvFAKE(namesv)
            && (SvPAD_OUR(namesv))
            && strEQ(SvPVX_const(namesv), name)

-           && COP_SEQ_RANGE_LOW(namesv) == PAD_MAX /* min */
+           && COP_SEQ_RANGE_LOW(namesv) == PERL_PADSEQ_INTRO

        )
            return offset;
     }
        )
            return offset;
     }


@@ -664,6 +781,28 @@ Perl_find_rundefsvoffset(pTHX)
 }
 
 /*
 }
 
 /*

+ * Returns a lexical $_, if there is one, at run time ; or the global one
+ * otherwise.
+ */
+
+SV *
+Perl_find_rundefsv(pTHX)
+{
+    SV *namesv;
+    int flags;
+    PADOFFSET po;
+
+    po = pad_findlex("$_", find_runcv(NULL), PL_curcop->cop_seq, 1,
+           NULL, &namesv, &flags);
+
+    if (po == NOT_IN_PAD
+       || (SvFLAGS(namesv) & (SVpad_NAME|SVpad_OUR)) == (SVpad_NAME|SVpad_OUR))
+       return DEFSV;
+
+    return PAD_SVl(po);
+}
+
+/*

 =for apidoc pad_findlex
 
 Find a named lexical anywhere in a chain of nested pads. Add fake entries
 =for apidoc pad_findlex
 
 Find a named lexical anywhere in a chain of nested pads. Add fake entries


@@ -724,11 +863,35 @@ S_pad_findlex(pTHX_ const char *name, const CV* cv, U32 seq, int warn,
            if (namesv && namesv != &PL_sv_undef
                    && strEQ(SvPVX_const(namesv), name))
            {
            if (namesv && namesv != &PL_sv_undef
                    && strEQ(SvPVX_const(namesv), name))
            {

-               if (SvFAKE(namesv))
+               if (SvFAKE(namesv)) {

                    fake_offset = offset; /* in case we don't find a real one */
                    fake_offset = offset; /* in case we don't find a real one */

-               else if (  seq >  COP_SEQ_RANGE_LOW(namesv)     /* min */
-                       && seq <= COP_SEQ_RANGE_HIGH(namesv))   /* max */
-                   break;
+                   continue;
+               }
+               /* is seq within the range _LOW to _HIGH ?
+                * This is complicated by the fact that PL_cop_seqmax
+                * may have wrapped around at some point */
+               if (COP_SEQ_RANGE_LOW(namesv) == PERL_PADSEQ_INTRO)
+                   continue; /* not yet introduced */
+
+               if (COP_SEQ_RANGE_HIGH(namesv) == PERL_PADSEQ_INTRO) {
+                   /* in compiling scope */
+                   if (
+                       (seq >  COP_SEQ_RANGE_LOW(namesv))
+                       ? (seq - COP_SEQ_RANGE_LOW(namesv) < (U32_MAX >> 1))
+                       : (COP_SEQ_RANGE_LOW(namesv) - seq > (U32_MAX >> 1))
+                   )
+                      break;
+               }
+               else if (
+                   (COP_SEQ_RANGE_LOW(namesv) > COP_SEQ_RANGE_HIGH(namesv))
+                   ?
+                       (  seq >  COP_SEQ_RANGE_LOW(namesv)
+                       || seq <= COP_SEQ_RANGE_HIGH(namesv))
+
+                   :    (  seq >  COP_SEQ_RANGE_LOW(namesv)
+                        && seq <= COP_SEQ_RANGE_HIGH(namesv))
+               )
+               break;

            }
        }
 
            }
        }
 


@@ -741,7 +904,7 @@ S_pad_findlex(pTHX_ const char *name, const CV* cv, U32 seq, int warn,
                 * instances. For now, we just test !CvUNIQUE(cv), but
                 * ideally, we should detect my's declared within loops
                 * etc - this would allow a wider range of 'not stayed
                 * instances. For now, we just test !CvUNIQUE(cv), but
                 * ideally, we should detect my's declared within loops
                 * etc - this would allow a wider range of 'not stayed

-                * shared' warnings. We also treated alreadly-compiled
+                * shared' warnings. We also treated already-compiled

                 * lexes as not multi as viewed from evals. */
 
                *out_flags = CvANON(cv) ?
                 * lexes as not multi as viewed from evals. */
 
                *out_flags = CvANON(cv) ?


@@ -781,9 +944,9 @@ S_pad_findlex(pTHX_ const char *name, const CV* cv, U32 seq, int warn,
                        ? CvANON(cv) && CvCLONE(cv) && !CvCLONED(cv)
                        : *out_flags & PAD_FAKELEX_ANON)
                {
                        ? CvANON(cv) && CvCLONE(cv) && !CvCLONED(cv)
                        : *out_flags & PAD_FAKELEX_ANON)
                {

-                   if (warn && ckWARN(WARN_CLOSURE))
-                       Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
-                           "Variable \"%s\" is not available", name);
+                   if (warn)
+                       Perl_ck_warner(aTHX_ packWARN(WARN_CLOSURE),
+                                      "Variable \"%s\" is not available", name);

                    *out_capture = NULL;
                }
 
                    *out_capture = NULL;
                }
 


@@ -823,9 +986,8 @@ S_pad_findlex(pTHX_ const char *name, const CV* cv, U32 seq, int warn,
                    if (SvPADSTALE(*out_capture)
                        && !SvPAD_STATE(name_svp[offset]))
                    {
                    if (SvPADSTALE(*out_capture)
                        && !SvPAD_STATE(name_svp[offset]))
                    {

-                       if (ckWARN(WARN_CLOSURE))
-                           Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
-                               "Variable \"%s\" is not available", name);
+                       Perl_ck_warner(aTHX_ packWARN(WARN_CLOSURE),
+                                      "Variable \"%s\" is not available", name);

                        *out_capture = NULL;
                    }
                }
                        *out_capture = NULL;
                    }
                }


@@ -866,23 +1028,30 @@ S_pad_findlex(pTHX_ const char *name, const CV* cv, U32 seq, int warn,
        return 0; /* this dummy (and invalid) value isnt used by the caller */
 
     {
        return 0; /* this dummy (and invalid) value isnt used by the caller */
 
     {

-       SV *new_namesv;
+       /* This relies on sv_setsv_flags() upgrading the destination to the same
+          type as the source, independent of the flags set, and on it being
+          "good" and only copying flag bits and pointers that it understands.
+       */
+       SV *new_namesv = newSVsv(*out_name_sv);

        AV *  const ocomppad_name = PL_comppad_name;
        PAD * const ocomppad = PL_comppad;
        PL_comppad_name = MUTABLE_AV(AvARRAY(padlist)[0]);
        PL_comppad = MUTABLE_AV(AvARRAY(padlist)[1]);
        PL_curpad = AvARRAY(PL_comppad);
 
        AV *  const ocomppad_name = PL_comppad_name;
        PAD * const ocomppad = PL_comppad;
        PL_comppad_name = MUTABLE_AV(AvARRAY(padlist)[0]);
        PL_comppad = MUTABLE_AV(AvARRAY(padlist)[1]);
        PL_curpad = AvARRAY(PL_comppad);
 

-       new_offset = pad_add_name(
-           SvPVX_const(*out_name_sv),
-           SvPAD_TYPED(*out_name_sv)
-                   ? SvSTASH(*out_name_sv) : NULL,
-           SvOURSTASH(*out_name_sv),
-           1,  /* fake */
-           SvPAD_STATE(*out_name_sv) ? 1 : 0 /* state variable ? */
-       );
+       new_offset
+           = pad_add_name_sv(new_namesv,
+                             (SvPAD_STATE(*out_name_sv) ? padadd_STATE : 0),
+                             SvPAD_TYPED(*out_name_sv)
+                             ? SvSTASH(*out_name_sv) : NULL,
+                             SvOURSTASH(*out_name_sv)
+                             );

 
 

-       new_namesv = AvARRAY(PL_comppad_name)[new_offset];
+       SvFAKE_on(new_namesv);
+       DEBUG_Xv(PerlIO_printf(Perl_debug_log,
+                              "Pad addname: %ld \"%.*s\" FAKE\n",
+                              (long)new_offset,
+                              (int) SvCUR(new_namesv), SvPVX(new_namesv)));

        PARENT_FAKELEX_FLAGS_set(new_namesv, *out_flags);
 
        PARENT_PAD_INDEX_set(new_namesv, 0);
        PARENT_FAKELEX_FLAGS_set(new_namesv, *out_flags);
 
        PARENT_PAD_INDEX_set(new_namesv, 0);


@@ -1016,6 +1185,7 @@ Perl_intro_my(pTHX)
     dVAR;
     SV **svp;
     I32 i;
     dVAR;
     SV **svp;
     I32 i;

+    U32 seq;

 
     ASSERT_CURPAD_ACTIVE("intro_my");
     if (! PL_min_intro_pending)
 
     ASSERT_CURPAD_ACTIVE("intro_my");
     if (! PL_min_intro_pending)


@@ -1025,8 +1195,10 @@ Perl_intro_my(pTHX)
     for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
        SV * const sv = svp[i];
 
     for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
        SV * const sv = svp[i];
 

-       if (sv && sv != &PL_sv_undef && !SvFAKE(sv) && !COP_SEQ_RANGE_HIGH(sv)) {
-           COP_SEQ_RANGE_HIGH_set(sv, PAD_MAX);        /* Don't know scope end yet. */
+       if (sv && sv != &PL_sv_undef && !SvFAKE(sv)
+           && COP_SEQ_RANGE_LOW(sv) == PERL_PADSEQ_INTRO)
+       {
+           COP_SEQ_RANGE_HIGH_set(sv, PERL_PADSEQ_INTRO); /* Don't know scope end yet. */

            COP_SEQ_RANGE_LOW_set(sv, PL_cop_seqmax);
            DEBUG_Xv(PerlIO_printf(Perl_debug_log,
                "Pad intromy: %ld \"%s\", (%lu,%lu)\n",
            COP_SEQ_RANGE_LOW_set(sv, PL_cop_seqmax);
            DEBUG_Xv(PerlIO_printf(Perl_debug_log,
                "Pad intromy: %ld \"%s\", (%lu,%lu)\n",


@@ -1036,12 +1208,16 @@ Perl_intro_my(pTHX)
            );
        }
     }
            );
        }
     }

+    seq = PL_cop_seqmax;
+    PL_cop_seqmax++;
+    if (PL_cop_seqmax == PERL_PADSEQ_INTRO) /* not a legal value */
+       PL_cop_seqmax++;

     PL_min_intro_pending = 0;
     PL_comppad_name_fill = PL_max_intro_pending; /* Needn't search higher */
     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
     PL_min_intro_pending = 0;
     PL_comppad_name_fill = PL_max_intro_pending; /* Needn't search higher */
     DEBUG_Xv(PerlIO_printf(Perl_debug_log,

-               "Pad intromy: seq -> %ld\n", (long)(PL_cop_seqmax+1)));
+               "Pad intromy: seq -> %ld\n", (long)(PL_cop_seqmax)));

 
 

-    return PL_cop_seqmax++;
+    return seq;

 }
 
 /*
 }
 
 /*


@@ -1066,17 +1242,18 @@ Perl_pad_leavemy(pTHX)
     if (PL_min_intro_pending && PL_comppad_name_fill < PL_min_intro_pending) {
        for (off = PL_max_intro_pending; off >= PL_min_intro_pending; off--) {
            const SV * const sv = svp[off];
     if (PL_min_intro_pending && PL_comppad_name_fill < PL_min_intro_pending) {
        for (off = PL_max_intro_pending; off >= PL_min_intro_pending; off--) {
            const SV * const sv = svp[off];

-           if (sv && sv != &PL_sv_undef
-                   && !SvFAKE(sv) && ckWARN_d(WARN_INTERNAL))
-               Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
-                           "%"SVf" never introduced",
-                           SVfARG(sv));
+           if (sv && sv != &PL_sv_undef && !SvFAKE(sv))
+               Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
+                                "%"SVf" never introduced",
+                                SVfARG(sv));

        }
     }
     /* "Deintroduce" my variables that are leaving with this scope. */
     for (off = AvFILLp(PL_comppad_name); off > PL_comppad_name_fill; off--) {
        const SV * const sv = svp[off];
        }
     }
     /* "Deintroduce" my variables that are leaving with this scope. */
     for (off = AvFILLp(PL_comppad_name); off > PL_comppad_name_fill; off--) {
        const SV * const sv = svp[off];

-       if (sv && sv != &PL_sv_undef && !SvFAKE(sv) && COP_SEQ_RANGE_HIGH(sv) == PAD_MAX) {
+       if (sv && sv != &PL_sv_undef && !SvFAKE(sv)
+           && COP_SEQ_RANGE_HIGH(sv) == PERL_PADSEQ_INTRO)
+       {

            COP_SEQ_RANGE_HIGH_set(sv, PL_cop_seqmax);
            DEBUG_Xv(PerlIO_printf(Perl_debug_log,
                "Pad leavemy: %ld \"%s\", (%lu,%lu)\n",
            COP_SEQ_RANGE_HIGH_set(sv, PL_cop_seqmax);
            DEBUG_Xv(PerlIO_printf(Perl_debug_log,
                "Pad leavemy: %ld \"%s\", (%lu,%lu)\n",


@@ -1087,6 +1264,8 @@ Perl_pad_leavemy(pTHX)
        }
     }
     PL_cop_seqmax++;
        }
     }
     PL_cop_seqmax++;

+    if (PL_cop_seqmax == PERL_PADSEQ_INTRO) /* not a legal value */
+       PL_cop_seqmax++;

     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
            "Pad leavemy: seq = %ld\n", (long)PL_cop_seqmax));
 }
     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
            "Pad leavemy: seq = %ld\n", (long)PL_cop_seqmax));
 }


@@ -1150,7 +1329,7 @@ Mark all the current temporaries for reuse
  * to  a shared TARG.  Such an alias will change randomly and unpredictably.
  * We avoid doing this until we can think of a Better Way.
  * GSAR 97-10-29 */
  * to  a shared TARG.  Such an alias will change randomly and unpredictably.
  * We avoid doing this until we can think of a Better Way.
  * GSAR 97-10-29 */

-void
+static void

 S_pad_reset(pTHX)
 {
     dVAR;
 S_pad_reset(pTHX)
 {
     dVAR;


@@ -1207,7 +1386,7 @@ Perl_pad_tidy(pTHX_ padtidy_type type)
      * so that for example the eval's CV in C<< sub { eval '$x' } >> gets
      * the right CvOUTSIDE.
      * If running with -d, *any* sub may potentially have an eval
      * so that for example the eval's CV in C<< sub { eval '$x' } >> gets
      * the right CvOUTSIDE.
      * If running with -d, *any* sub may potentially have an eval

-     * excuted within it.
+     * executed within it.

      */
 
     if (PL_cv_has_eval || PL_perldb) {
      */
 
     if (PL_cv_has_eval || PL_perldb) {


@@ -1253,27 +1432,37 @@ Perl_pad_tidy(pTHX_ padtidy_type type)
     else if (type == padtidy_SUB) {
        /* XXX DAPM this same bit of code keeps appearing !!! Rationalise? */
        AV * const av = newAV();                        /* Will be @_ */
     else if (type == padtidy_SUB) {
        /* XXX DAPM this same bit of code keeps appearing !!! Rationalise? */
        AV * const av = newAV();                        /* Will be @_ */

-       av_extend(av, 0);

        av_store(PL_comppad, 0, MUTABLE_SV(av));
        AvREIFY_only(av);
     }
 
        av_store(PL_comppad, 0, MUTABLE_SV(av));
        AvREIFY_only(av);
     }
 

-    /* XXX DAPM rationalise these two similar branches */
-
-    if (type == padtidy_SUB) {
+    if (type == padtidy_SUB || type == padtidy_FORMAT) {
+       SV * const * const namep = AvARRAY(PL_comppad_name);

        PADOFFSET ix;
        for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
            if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
                continue;
        PADOFFSET ix;
        for (ix = AvFILLp(PL_comppad); ix > 0; 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]);
-       }
-    }
-    else if (type == padtidy_FORMAT) {
-       PADOFFSET ix;
-       for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
-           if (!SvPADMY(PL_curpad[ix]) && !SvIMMORTAL(PL_curpad[ix]))
+           if (!SvPADMY(PL_curpad[ix])) {

                SvPADTMP_on(PL_curpad[ix]);
                SvPADTMP_on(PL_curpad[ix]);

+           } else if (!SvFAKE(namep[ix])) {
+               /* This is a work around for how the current implementation of
+                  ?{ } blocks in regexps interacts with lexicals.
+
+                  One of our lexicals.
+                  Can't do this on all lexicals, otherwise sub baz() won't
+                  compile in
+
+                  my $foo;
+
+                  sub bar { ++$foo; }
+
+                  sub baz { ++$foo; }
+
+                  because completion of compiling &bar calling pad_tidy()
+                  would cause (top level) $foo to be marked as stale, and
+                  "no longer available".  */
+               SvPADSTALE_on(PL_curpad[ix]);
+           }

        }
     }
     PL_curpad = AvARRAY(PL_comppad);
        }
     }
     PL_curpad = AvARRAY(PL_comppad);


@@ -1308,17 +1497,6 @@ Perl_pad_free(pTHX_ PADOFFSET po)
 
     if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
        SvPADTMP_off(PL_curpad[po]);
 
     if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
        SvPADTMP_off(PL_curpad[po]);

-#ifdef USE_ITHREADS
-       /* SV could be a shared hash key (eg bugid #19022) */
-       if (
-#ifdef PERL_OLD_COPY_ON_WRITE
-           !SvIsCOW(PL_curpad[po])
-#else
-           !SvFAKE(PL_curpad[po])
-#endif
-           )
-           SvREADONLY_off(PL_curpad[po]);      /* could be a freed constant */
-#endif

     }
     if ((I32)po < PL_padix)
        PL_padix = po - 1;
     }
     if ((I32)po < PL_padix)
        PL_padix = po - 1;


@@ -1491,7 +1669,7 @@ Perl_cv_clone(pTHX_ CV *proto)
     SAVESPTR(PL_compcv);
 
     cv = PL_compcv = MUTABLE_CV(newSV_type(SvTYPE(proto)));
     SAVESPTR(PL_compcv);
 
     cv = PL_compcv = MUTABLE_CV(newSV_type(SvTYPE(proto)));

-    CvFLAGS(cv) = CvFLAGS(proto) & ~(CVf_CLONE|CVf_WEAKOUTSIDE);
+    CvFLAGS(cv) = CvFLAGS(proto) & ~(CVf_CLONE|CVf_WEAKOUTSIDE|CVf_CVGV_RC);

     CvCLONED_on(cv);
 
 #ifdef USE_ITHREADS
     CvCLONED_on(cv);
 
 #ifdef USE_ITHREADS


@@ -1500,8 +1678,8 @@ Perl_cv_clone(pTHX_ CV *proto)
 #else
     CvFILE(cv)         = CvFILE(proto);
 #endif
 #else
     CvFILE(cv)         = CvFILE(proto);
 #endif

-    CvGV(cv)           = CvGV(proto);
-    CvSTASH(cv)                = CvSTASH(proto);
+    CvGV_set(cv,CvGV(proto));
+    CvSTASH_set(cv, CvSTASH(proto));

     OP_REFCNT_LOCK;
     CvROOT(cv)         = OpREFCNT_inc(CvROOT(proto));
     OP_REFCNT_UNLOCK;
     OP_REFCNT_LOCK;
     CvROOT(cv)         = OpREFCNT_inc(CvROOT(proto));
     OP_REFCNT_UNLOCK;


@@ -1515,7 +1693,7 @@ Perl_cv_clone(pTHX_ CV *proto)
     CvPADLIST(cv) = pad_new(padnew_CLONE|padnew_SAVE);
 
     av_fill(PL_comppad, fpad);
     CvPADLIST(cv) = pad_new(padnew_CLONE|padnew_SAVE);
 
     av_fill(PL_comppad, fpad);

-    for (ix = fname; ix >= 0; ix--)
+    for (ix = fname; ix > 0; ix--)

        av_store(PL_comppad_name, ix, SvREFCNT_inc(pname[ix]));
 
     PL_curpad = AvARRAY(PL_comppad);
        av_store(PL_comppad_name, ix, SvREFCNT_inc(pname[ix]));
 
     PL_curpad = AvARRAY(PL_comppad);


@@ -1533,9 +1711,8 @@ Perl_cv_clone(pTHX_ CV *proto)
                   while my $x if $false can leave an active var marked as
                   stale. And state vars are always available */
                if (SvPADSTALE(sv) && !SvPAD_STATE(namesv)) {
                   while my $x if $false can leave an active var marked as
                   stale. And state vars are always available */
                if (SvPADSTALE(sv) && !SvPAD_STATE(namesv)) {

-                   if (ckWARN(WARN_CLOSURE))
-                       Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
-                           "Variable \"%s\" is not available", SvPVX_const(namesv));
+                   Perl_ck_warner(aTHX_ packWARN(WARN_CLOSURE),
+                                  "Variable \"%s\" is not available", SvPVX_const(namesv));

                    sv = NULL;
                }
                else 
                    sv = NULL;
                }
                else 


@@ -1692,7 +1869,6 @@ Perl_pad_push(pTHX_ PADLIST *padlist, int depth)
            }
        }
        av = newAV();
            }
        }
        av = newAV();

-       av_extend(av, 0);

        av_store(newpad, 0, MUTABLE_SV(av));
        AvREIFY_only(av);
 
        av_store(newpad, 0, MUTABLE_SV(av));
        AvREIFY_only(av);
 


@@ -1713,6 +1889,129 @@ Perl_pad_compname_type(pTHX_ const PADOFFSET po)
     return NULL;
 }
 
     return NULL;
 }
 

+#if defined(USE_ITHREADS)
+
+#  define av_dup_inc(s,t)      MUTABLE_AV(sv_dup_inc((const SV *)s,t))
+
+AV *
+Perl_padlist_dup(pTHX_ AV *const srcpad, CLONE_PARAMS *const param)
+{
+    AV *dstpad;
+    PERL_ARGS_ASSERT_PADLIST_DUP;
+
+    if (!srcpad)
+       return NULL;
+
+    assert(!AvREAL(srcpad));
+
+    if (param->flags & CLONEf_COPY_STACKS
+       || SvREFCNT(AvARRAY(srcpad)[1]) > 1) {
+       /* XXX padlists are real, but pretend to be not */
+       AvREAL_on(srcpad);
+       dstpad = av_dup_inc(srcpad, param);
+       AvREAL_off(srcpad);
+       AvREAL_off(dstpad);
+       assert (SvREFCNT(AvARRAY(srcpad)[1]) == 1);
+    } else {
+       /* CvDEPTH() on our subroutine will be set to 0, so there's no need
+          to build anything other than the first level of pads.  */
+
+       I32 ix = AvFILLp((const AV *)AvARRAY(srcpad)[1]);
+       AV *pad1;
+       const I32 names_fill = AvFILLp((const AV *)(AvARRAY(srcpad)[0]));
+       const AV *const srcpad1 = (const AV *) AvARRAY(srcpad)[1];
+       SV **oldpad = AvARRAY(srcpad1);
+       SV **names;
+       SV **pad1a;
+       AV *args;
+       /* look for it in the table first.
+          I *think* that it shouldn't be possible to find it there.
+          Well, except for how Perl_sv_compile_2op() "works" :-(   */
+       dstpad = (AV*)ptr_table_fetch(PL_ptr_table, srcpad);
+
+       if (dstpad)
+           return dstpad;
+
+       dstpad = newAV();
+       ptr_table_store(PL_ptr_table, srcpad, dstpad);
+       AvREAL_off(dstpad);
+       av_extend(dstpad, 1);
+       AvARRAY(dstpad)[0] = MUTABLE_SV(av_dup_inc(AvARRAY(srcpad)[0], param));
+       names = AvARRAY(AvARRAY(dstpad)[0]);
+
+       pad1 = newAV();
+
+       av_extend(pad1, ix);
+       AvARRAY(dstpad)[1] = MUTABLE_SV(pad1);
+       pad1a = AvARRAY(pad1);
+       AvFILLp(dstpad) = 1;
+
+       if (ix > -1) {
+           AvFILLp(pad1) = ix;
+
+           for ( ;ix > 0; ix--) {
+               if (!oldpad[ix]) {
+                   pad1a[ix] = NULL;
+               } else if (names_fill >= ix && names[ix] != &PL_sv_undef) {
+                   const char sigil = SvPVX_const(names[ix])[0];
+                   if ((SvFLAGS(names[ix]) & SVf_FAKE)
+                       || (SvFLAGS(names[ix]) & SVpad_STATE)
+                       || sigil == '&')
+                       {
+                           /* outer lexical or anon code */
+                           pad1a[ix] = sv_dup_inc(oldpad[ix], param);
+                       }
+                   else {              /* our own lexical */
+                       if(SvPADSTALE(oldpad[ix]) && SvREFCNT(oldpad[ix]) > 1) {
+                           /* This is a work around for how the current
+                              implementation of ?{ } blocks in regexps
+                              interacts with lexicals.  */
+                           pad1a[ix] = sv_dup_inc(oldpad[ix], param);
+                       } else {
+                           SV *sv; 
+                           
+                           if (sigil == '@')
+                               sv = MUTABLE_SV(newAV());
+                           else if (sigil == '%')
+                               sv = MUTABLE_SV(newHV());
+                           else
+                               sv = newSV(0);
+                           pad1a[ix] = sv;
+                           SvPADMY_on(sv);
+                       }
+                   }
+               }
+               else if (IS_PADGV(oldpad[ix]) || IS_PADCONST(oldpad[ix])) {
+                   pad1a[ix] = sv_dup_inc(oldpad[ix], param);
+               }
+               else {
+                   /* save temporaries on recursion? */
+                   SV * const sv = newSV(0);
+                   pad1a[ix] = sv;
+
+                   /* SvREFCNT(oldpad[ix]) != 1 for some code in threads.xs
+                      FIXTHAT before merging this branch.
+                      (And I know how to) */
+                   if (SvPADMY(oldpad[ix]))
+                       SvPADMY_on(sv);
+                   else
+                       SvPADTMP_on(sv);
+               }
+           }
+
+           if (oldpad[0]) {
+               args = newAV();                 /* Will be @_ */
+               AvREIFY_only(args);
+               pad1a[0] = (SV *)args;
+           }
+       }
+    }
+
+    return dstpad;
+}
+
+#endif
+

 /*
  * Local variables:
  * c-indentation-style: bsd
 /*
  * Local variables:
  * c-indentation-style: bsd