This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
In S_pad_check_dup(), no need to check the 0th name entry.
[perl5.git] / pad.c
diff --git a/pad.c b/pad.c
index d395e71..06cadbb 100644 (file)
--- a/pad.c
+++ b/pad.c
@@ -160,6 +160,7 @@ Perl_pad_new(pTHX_ int flags)
 {
     dVAR;
     AV *padlist, *padname, *pad;
+    SV **ary;
 
     ASSERT_CURPAD_LEGAL("pad_new");
 
@@ -209,14 +210,23 @@ Perl_pad_new(pTHX_ int flags)
     }
 
     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 */
 
-    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;
@@ -236,108 +246,157 @@ Perl_pad_new(pTHX_ int flags)
     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
-Perl_pad_undef(pTHX_ CV* cv)
+Perl_cv_undef(pTHX_ CV *cv)
 {
     dVAR;
-    I32 ix;
-    const PADLIST * const padlist = CvPADLIST(cv);
-
-    PERL_ARGS_ASSERT_PAD_UNDEF;
+    const PADLIST *padlist = CvPADLIST(cv);
 
-    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,
-         "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) {
-           if (sv == (const SV *)PL_comppad_name)
-               PL_comppad_name = NULL;
-           else if (sv == (const SV *)PL_comppad) {
-               PL_comppad = NULL;
-               PL_curpad = NULL;
+       ix = AvFILLp(padlist);
+       while (ix >= 0) {
+           SV* const sv = AvARRAY(padlist)[ix--];
+           if (sv) {
+               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;
     }
-    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);
+    }
+    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,
@@ -603,7 +662,7 @@ S_pad_check_dup(pTHX_ SV *name, const U32 flags, const HV *ourstash)
     }
     /* check the rest of the pad */
     if (is_our) {
-       do {
+       while (off > 0) {
            SV * const sv = svp[off];
            if (sv
                && sv != &PL_sv_undef
@@ -619,7 +678,8 @@ S_pad_check_dup(pTHX_ SV *name, const U32 flags, const HV *ourstash)
                        "\t(Did you mean \"local\" instead of \"our\"?)\n");
                break;
            }
-       } while ( off-- > 0 );
+           --off;
+       }
     }
 }