1 files changed, 33 insertions, 0 deletions
diff --git a/src/internal/testlog/exit.go b/src/internal/testlog/exit.go
new file mode 100644
index 0000000000..e15defdb5b
--- /dev/null
+++ b/src/internal/testlog/exit.go
@@ -0,0 +1,33 @@
+// Copyright 2020 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.
+
+package testlog
+
+import "sync"
+
+// PanicOnExit0 reports whether to panic on a call to os.Exit(0).
+// This is in the testlog package because, like other definitions in
+// package testlog, it is a hook between the testing package and the
+// os package. This is used to ensure that an early call to os.Exit(0)
+// does not cause a test to pass.
+func PanicOnExit0() bool {
+	panicOnExit0.mu.Lock()
+	defer panicOnExit0.mu.Unlock()
+	return panicOnExit0.val
+}
+
+// panicOnExit0 is the flag used for PanicOnExit0. This uses a lock
+// because the value can be cleared via a timer call that may race
+// with calls to os.Exit
+var panicOnExit0 struct {
+	mu  sync.Mutex
+	val bool
+}
+
+// SetPanicOnExit0 sets panicOnExit0 to v.
+func SetPanicOnExit0(v bool) {
+	panicOnExit0.mu.Lock()
+	defer panicOnExit0.mu.Unlock()
+	panicOnExit0.val = v
+}