From c7e1453e3da5ca2550bb780d1cea43e5d05af3ec Mon Sep 17 00:00:00 2001
From: Chris Manghane <cmang@golang.org>
Date: Tue, 9 Dec 2014 06:52:17 -0800
Subject: [PATCH] cmd/internal/gc: do not show computed value in type error

Fixes #9076.

Change-Id: Ib41a452fa9aa9fecf19f65c36d13715923548041
Reviewed-on: https://go-review.googlesource.com/1250
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Chris Manghane <cmang@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---
 src/cmd/internal/gc/fmt.go  | 10 +++++-----
 test/fixedbugs/issue6964.go |  2 +-
 test/fixedbugs/issue9076.go | 15 +++++++++++++++
 3 files changed, 21 insertions(+), 6 deletions(-)
 create mode 100644 test/fixedbugs/issue9076.go

diff --git a/src/cmd/internal/gc/fmt.go b/src/cmd/internal/gc/fmt.go
index ce736766558..5ad607e04eb 100644
--- a/src/cmd/internal/gc/fmt.go
+++ b/src/cmd/internal/gc/fmt.go
@@ -1261,16 +1261,16 @@ func exprfmt(n *Node, prec int) string {
 		return f
 
 	case OLITERAL: // this is a bit of a mess
+		if n.Orig != nil && n.Orig != n {
+			var f string
+			f += exprfmt(n.Orig, prec)
+			return f
+		}
 		if fmtmode == FErr && n.Sym != nil {
 			var f string
 			f += fmt.Sprintf("%v", Sconv(n.Sym, 0))
 			return f
 		}
-		if n.Val.Ctype == CTNIL && n.Orig != nil && n.Orig != n {
-			var f string
-			f += exprfmt(n.Orig, prec)
-			return f
-		}
 		if n.Type != nil && n.Type != Types[n.Type.Etype] && n.Type != idealbool && n.Type != idealstring {
 			// Need parens when type begins with what might
 			// be misinterpreted as a unary operator: * or <-.
diff --git a/test/fixedbugs/issue6964.go b/test/fixedbugs/issue6964.go
index 821735c082b..8f4b60db3ce 100644
--- a/test/fixedbugs/issue6964.go
+++ b/test/fixedbugs/issue6964.go
@@ -7,5 +7,5 @@
 package main
 
 func main() {
-	_ = string(-4 + 2i + 2) // ERROR "-4\+2i"
+	_ = string(-4 + 2i + 2) // ERROR "-4 \+ 2i"
 }
diff --git a/test/fixedbugs/issue9076.go b/test/fixedbugs/issue9076.go
new file mode 100644
index 00000000000..ad1cd5db0c6
--- /dev/null
+++ b/test/fixedbugs/issue9076.go
@@ -0,0 +1,15 @@
+// errorcheck
+
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 9076: cmd/gc shows computed values in error messages instead of original expression.
+
+package main
+
+import "unsafe"
+
+const Hundred = 100
+var _ int32 = 100/unsafe.Sizeof(int(0)) + 1 // GC_ERROR "100 \/ unsafe.Sizeof\(int\(0\)\) \+ 1"
+var _ int32 = Hundred/unsafe.Sizeof(int(0)) + 1 // GC_ERROR "Hundred \/ unsafe.Sizeof\(int\(0\)\) \+ 1"