From: Dave Cheney <dave@cheney.net>
Date: Thu, 21 Aug 2014 23:10:33 +0000 (+1000)
Subject: cmd/ld: fix undefined behaviour in pcln.c
X-Git-Tag: go1.4beta1~758
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=f129370b3e5d53a384281503f658b3a5b115fbd5;p=gostls13.git

cmd/ld: fix undefined behaviour in pcln.c

Update #8527

Fixes, src/cmd/6l/../ld/pcln.c:93:18: runtime error: left shift of negative value -2

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/127440043
---

diff --git a/src/cmd/ld/pcln.c b/src/cmd/ld/pcln.c
index 4c2ffa78e1..17f4f992fc 100644
--- a/src/cmd/ld/pcln.c
+++ b/src/cmd/ld/pcln.c
@@ -90,7 +90,7 @@ renumberfiles(Link *ctxt, LSym **files, int nfiles, Pcdata *d)
 		}
 		dv = val - newval;
 		newval = val;
-		v = (uint32)(dv<<1) ^ (uint32)(int32)(dv>>31);
+		v = ((uint32)dv<<1) ^ (uint32)(int32)(dv>>31);
 		addvarint(&out, v);
 
 		// pc delta