code review 12609043: runtime: fix traceback in cgo programs

src/pkg/runtime/crash_cgo_test.go

 // Copyright 2012 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.
 
 // +build cgo
 
 package runtime_test
 
 import (
         "runtime"
         "testing"
 )
 
 func TestCgoCrashHandler(t *testing.T) {
         testCrashHandler(t, true)
 }
 
 func TestCgoSignalDeadlock(t *testing.T) {
         if testing.Short() && runtime.GOOS == "windows" {
                 t.Skip("Skipping in short mode") // takes up to 64 seconds
         }
         got := executeTest(t, cgoSignalDeadlockSource, nil)
+        want := "OK\n"
+        if got != want {
+                t.Fatalf("expected %q, but got %q", want, got)
+        }
+}
+
+func TestCgoTraceback(t *testing.T) {
+        got := executeTest(t, cgoTracebackSource, nil)
         want := "OK\n"
         if got != want {
                 t.Fatalf("expected %q, but got %q", want, got)
         }
 }
 
 const cgoSignalDeadlockSource = `
 package main
 
 import "C"
@@ skipping 50 matching lines @@
         ping <- true
         select {
         case <-ping:
         case <-time.After(time.Second):
                 fmt.Printf("HANG\n")
                 return
         }
         fmt.Printf("OK\n")
 }
 `
+
+const cgoTracebackSource = `
+package main
+
+/* void foo(void) {} */
+import "C"
+
+import (
+        "fmt"
+        "runtime"
+)
+
+func main() {
+        C.foo()
+        buf := make([]byte, 1)
+        runtime.Stack(buf, true)
+        fmt.Printf("OK\n")
+}
+`