From: Dave Mitchell <davem@fdisolutions.com>
Date: Thu, 19 Dec 2002 19:00:21 +0000 (+0000)
Subject: new flag SvPADSTALE
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=d9d18af660f47fb8e7eedfe8204daab3270e514f;p=p5sagit%2Fp5-mst-13.2.git

new flag SvPADSTALE
Message-ID: <20021219190021.D9530@fdgroup.com>

p4raw-id: //depot/perl@18410
---

diff --git a/dump.c b/dump.c
index ddd5ae5..1053f87 100644
--- a/dump.c
+++ b/dump.c
@@ -942,6 +942,7 @@ Perl_do_sv_dump(pTHX_ I32 level, PerlIO *file, SV *sv, I32 nest, I32 maxnest, bo
 		   (int)(PL_dumpindent*level), "", (IV)SvREFCNT(sv),
 		   (int)(PL_dumpindent*level), "");
 
+    if (flags & SVs_PADSTALE)	sv_catpv(d, "PADSTALE,");
     if (flags & SVs_PADTMP)	sv_catpv(d, "PADTMP,");
     if (flags & SVs_PADMY)	sv_catpv(d, "PADMY,");
     if (flags & SVs_TEMP)	sv_catpv(d, "TEMP,");
diff --git a/scope.c b/scope.c
index d3a4c36..bfd2969 100644
--- a/scope.c
+++ b/scope.c
@@ -548,6 +548,7 @@ Perl_save_clearsv(pTHX_ SV **svp)
     SSCHECK(2);
     SSPUSHLONG((long)(svp-PL_curpad));
     SSPUSHINT(SAVEt_CLEARSV);
+    SvPADSTALE_off(*svp); /* mark lexical as active */
 }
 
 void
@@ -918,6 +919,7 @@ Perl_leave_scope(pTHX_ I32 base)
 		    (void)SvOOK_off(sv);
 		    break;
 		}
+		SvPADSTALE_on(sv); /* mark as no longer live */
 	    }
 	    else {	/* Someone has a claim on this, so abandon it. */
 		U32 padflags = SvFLAGS(sv) & (SVs_PADMY|SVs_PADTMP);
@@ -927,7 +929,9 @@ Perl_leave_scope(pTHX_ I32 base)
 		default:	*(SV**)ptr = NEWSV(0,0);	break;
 		}
 		SvREFCNT_dec(sv);	/* Cast current value to the winds. */
-		SvFLAGS(*(SV**)ptr) |= padflags; /* preserve pad nature */
+		/* preserve pad nature, but also mark as not live
+		 * for any closure capturing */
+		SvFLAGS(*(SV**)ptr) |= padflags & SVs_PADSTALE;
 	    }
 	    break;
 	case SAVEt_DELETE:
diff --git a/sv.h b/sv.h
index 19d8bb3..d87ba11 100644
--- a/sv.h
+++ b/sv.h
@@ -148,7 +148,7 @@ perform the upgrade if necessary.  See C<svtype>.
 
 #define SvUPGRADE(sv, mt) (SvTYPE(sv) >= mt || sv_upgrade(sv, mt))
 
-/* XXX spare */
+#define SVs_PADSTALE	0x00000100	/* lexical has gone out of scope */
 #define SVs_PADTMP	0x00000200	/* in use as tmp */
 #define SVs_PADMY	0x00000400	/* in use a "my" variable */
 #define SVs_TEMP	0x00000800	/* string is stealable? */
@@ -637,6 +637,10 @@ and leaves the UTF8 status as it was.
 
 #define SvTHINKFIRST(sv)	(SvFLAGS(sv) & SVf_THINKFIRST)
 
+#define SvPADSTALE(sv)		(SvFLAGS(sv) & SVs_PADSTALE)
+#define SvPADSTALE_on(sv)	(SvFLAGS(sv) |= SVs_PADSTALE)
+#define SvPADSTALE_off(sv)	(SvFLAGS(sv) &= ~SVs_PADSTALE)
+
 #define SvPADTMP(sv)		(SvFLAGS(sv) & SVs_PADTMP)
 #define SvPADTMP_on(sv)		(SvFLAGS(sv) |= SVs_PADTMP)
 #define SvPADTMP_off(sv)	(SvFLAGS(sv) &= ~SVs_PADTMP)