From: Cherry Zhang <cherryyz@google.com>
Date: Wed, 10 Jul 2019 14:58:59 +0000 (-0400)
Subject: test: add a test for gccgo bug in handling break statement in a select
X-Git-Tag: go1.13rc1~107
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=a1bcee4f1c196681397f1140e4338d056a188a3e;p=gostls13.git

test: add a test for gccgo bug in handling break statement in a select

Gccgo CL 184998 added optimizations for one- and two-case select
statements. But it didn't handle break statement in the select
case correctly. The fix is CL 185519. This CL adds a test.

Change-Id: Ide1b199f106172b41dd77c1f6e0d662fccdd8cc5
Reviewed-on: https://go-review.googlesource.com/c/go/+/185520
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
---

diff --git a/test/chan/select8.go b/test/chan/select8.go
new file mode 100644
index 0000000000..20bca3a0f9
--- /dev/null
+++ b/test/chan/select8.go
@@ -0,0 +1,55 @@
+// run
+
+// Copyright 2019 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.
+
+// Test break statements in a select.
+// Gccgo had a bug in handling this.
+// Test 1,2,3-case selects, so it covers both the general
+// code path and the specialized optimizations for one-
+// and two-case selects.
+
+package main
+
+var ch = make(chan int)
+
+func main() {
+	go func() {
+		for {
+			ch <- 5
+		}
+	}()
+
+	select {
+	case <-ch:
+		break
+		panic("unreachable")
+	}
+
+	select {
+	default:
+		break
+		panic("unreachable")
+	}
+
+	select {
+	case <-ch:
+		break
+		panic("unreachable")
+	default:
+		break
+		panic("unreachable")
+	}
+
+	select {
+	case <-ch:
+		break
+		panic("unreachable")
+	case ch <- 10:
+		panic("unreachable")
+	default:
+		break
+		panic("unreachable")
+	}
+}