cmd/cgo: use same Go type for typedef to anonymous struct

If we see a typedef to an anonymous struct more than once,
presumably in two different Go files that import "C", use the
same Go type name.

Fixes issue 8133.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://codereview.appspot.com/102080043

3 files changed, 35 insertions, 0 deletions

diff --git a/misc/cgo/test/issue8331.h b/misc/cgo/test/issue8331.h
new file mode 100644
index 000000000..936ae9d5c
--- /dev/null
+++ b/misc/cgo/test/issue8331.h
@@ -0,0 +1,7 @@
+// 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.
+
+typedef struct {
+	int i;
+} issue8331;
diff --git a/misc/cgo/test/issue8331a.go b/misc/cgo/test/issue8331a.go
new file mode 100644
index 000000000..7fa55be43
--- /dev/null
+++ b/misc/cgo/test/issue8331a.go
@@ -0,0 +1,15 @@
+// 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 8331.  A typedef of an unnamed struct is the same struct when
+// #include'd twice.  No runtime test; just make sure it compiles.
+
+package cgotest
+
+// #include "issue8331.h"
+import "C"
+
+func issue8331a() C.issue8331 {
+	return issue8331Var
+}
diff --git a/misc/cgo/test/issue8331b.go b/misc/cgo/test/issue8331b.go
new file mode 100644
index 000000000..d52aed63e
--- /dev/null
+++ b/misc/cgo/test/issue8331b.go
@@ -0,0 +1,13 @@
+// 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 8331.  A typedef of an unnamed struct is the same struct when
+// #include'd twice.  No runtime test; just make sure it compiles.
+
+package cgotest
+
+// #include "issue8331.h"
+import "C"
+
+var issue8331Var C.issue8331