From: Nicholas Clark <nick@ccl4.org>
Date: Fri, 15 Oct 2004 17:11:08 +0000 (+0000)
Subject: Implement sv_svset _nosteal variants by passing a flag into
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=5fcdf167f4386a3583bf0db9d98b989639295a45;p=p5sagit%2Fp5-mst-13.2.git

Implement sv_svset _nosteal variants by passing a flag into
sv_set_flags rather than messing with the SvTEMP() flag on either
side of the call.

p4raw-id: //depot/perl@23373
---

diff --git a/sv.c b/sv.c
index 3fac004..aec9802 100644
--- a/sv.c
+++ b/sv.c
@@ -4130,8 +4130,9 @@ function if the source SV needs to be reused. Does not handle 'set' magic.
 Loosely speaking, it performs a copy-by-value, obliterating any previous
 content of the destination.
 If the C<flags> parameter has the C<SV_GMAGIC> bit set, will C<mg_get> on
-C<ssv> if appropriate, else not. C<sv_setsv> and C<sv_setsv_nomg> are
-implemented in terms of this function.
+C<ssv> if appropriate, else not. If the C<flags> parameter has the
+C<NOSTEAL> bit set then the buffers of temps will not be stolen. <sv_setsv>
+and C<sv_setsv_nomg> are implemented in terms of this function.
 
 You probably want to use one of the assortment of wrappers, such as
 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
@@ -4515,6 +4516,8 @@ Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
             !(isSwipe =
                  (sflags & SVs_TEMP) &&   /* slated for free anyway? */
                  !(sflags & SVf_OOK) &&   /* and not involved in OOK hack? */
+	         (!(flags & SV_NOSTEAL)) &&
+					/* and we're allowed to steal temps */
                  SvREFCNT(sstr) == 1 &&   /* and no other references to it? */
                  SvLEN(sstr) 	&&	  /* and really is a string */
 	    			/* and won't be needed again, potentially */
diff --git a/sv.h b/sv.h
index c26da9d..e80c755 100644
--- a/sv.h
+++ b/sv.h
@@ -1103,6 +1103,7 @@ Like C<sv_catsv> but doesn't process magic.
 #define SV_GMAGIC		2
 #define SV_COW_DROP_PV		4
 #define SV_UTF8_NO_ENCODING	8
+#define SV_NOSTEAL		16
 
 /* We are about to replace the SV's current value. So if it's copy on write
    we need to normalise it. Use the SV_COW_DROP_PV flag hint to say that
@@ -1242,10 +1243,7 @@ Returns a pointer to the character buffer.
 #define SvSetSV_nosteal_and(dst,src,finally) \
 	STMT_START {					\
 	    if ((dst) != (src)) {			\
-		U32 tMpF = SvFLAGS(src) & SVs_TEMP;	\
-		SvTEMP_off(src);			\
-		sv_setsv(dst, src);			\
-		SvFLAGS(src) |= tMpF;			\
+		sv_setsv_flags(dst, src, SV_GMAGIC | SV_NOSTEAL);	\
 		finally;				\
 	    }						\
 	} STMT_END