From: Rob Pike <r@golang.org>
Date: Fri, 21 Nov 2008 01:19:45 +0000 (-0800)
Subject: tweak pcs in traceback so they point to calling line instead of line after call.
X-Git-Tag: weekly.2009-11-06~2643
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=ec913c42b3d1a0a7f380aee5c1ce597f0d2f0f07;p=gostls13.git

tweak pcs in traceback so they point to calling line instead of line after call.

R=rsc
DELTA=2  (0 added, 0 deleted, 2 changed)
OCL=19745
CL=19745
---

diff --git a/src/runtime/print.c b/src/runtime/print.c
index de9cabfbb1..26d59a7390 100644
--- a/src/runtime/print.c
+++ b/src/runtime/print.c
@@ -32,7 +32,7 @@ void
 sys·printpc(void *p)
 {
 	prints("PC=0x");
-	sys·printpointer(sys·getcallerpc(p));
+	sys·printpointer((byte*)sys·getcallerpc(p) - 1);	// -1 to get to CALL instr.
 }
 
 void
diff --git a/src/runtime/rt2_amd64.c b/src/runtime/rt2_amd64.c
index a3433678b2..38eeddb495 100644
--- a/src/runtime/rt2_amd64.c
+++ b/src/runtime/rt2_amd64.c
@@ -70,7 +70,7 @@ traceback(uint8 *pc, uint8 *sp, void* r15)
 
 		/* print this frame */
 		prints("0x");
-		sys·printpointer(callpc);
+		sys·printpointer(callpc  - 1);	// -1 to get to CALL instr.
 		prints("?zi\n");
 		prints("\t");
 		prints(name);