From a6c151c04db078d856d9bae182646c11f4662a1b Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Wed, 25 Sep 2013 10:19:24 -0700
Subject: [PATCH] go.tools/go/types: (panic(0)) (parenthesized) is a
 terminating statement

R=adonovan
CC=golang-dev
https://golang.org/cl/13913043
---
 go/types/return.go          | 4 ++--
 go/types/testdata/stmt1.src | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/go/types/return.go b/go/types/return.go
index ad5b22d00cb..fb8ab6dcf3b 100644
--- a/go/types/return.go
+++ b/go/types/return.go
@@ -28,8 +28,8 @@ func (check *checker) isTerminating(s ast.Stmt, label string) bool {
 		return check.isTerminating(s.Stmt, s.Label.Name)
 
 	case *ast.ExprStmt:
-		// the predeclared panic() function is terminating
-		if call, _ := s.X.(*ast.CallExpr); call != nil {
+		// the predeclared (possibly parenthesized) panic() function is terminating
+		if call, _ := unparen(s.X).(*ast.CallExpr); call != nil {
 			if id, _ := call.Fun.(*ast.Ident); id != nil {
 				if obj := check.topScope.LookupParent(id.Name); obj != nil {
 					if b, _ := obj.(*Builtin); b != nil && b.id == _Panic {
diff --git a/go/types/testdata/stmt1.src b/go/types/testdata/stmt1.src
index 537c3f4a348..a2955e6fd05 100644
--- a/go/types/testdata/stmt1.src
+++ b/go/types/testdata/stmt1.src
@@ -11,6 +11,7 @@ func _() {}
 func _() int {} /* ERROR "missing return" */
 
 func _() int { panic(0) }
+func _() int { (panic(0)) }
 
 // block statements
 func _(x, y int) (z int) {