[PCH/preamble] Make sure that if the preamble/PCH was serialized with errors that we set diagnostic engine state appropriately.

Otherwise there can be a crash with CFG analysis warnings doing work on invalid AST.

Fixes crash of rdar://26224134

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@275313 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 0 deletions

diff --git a/test/PCH/chain-invalid-code.cpp b/test/PCH/chain-invalid-code.cpp
new file mode 100644
index 0000000000..9de88f0cee
--- /dev/null
+++ b/test/PCH/chain-invalid-code.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -fsyntax-only %s -chain-include %s -Wuninitialized -Wunused -verify
+
+// Make sure there is no crash.
+
+#ifndef HEADER
+#define HEADER
+
+#include "non-existent-header.h"
+
+class A {
+public:
+  ~A();
+};
+
+class ForwardCls;
+struct B {
+  ForwardCls f;
+  A a;
+};
+
+#else
+
+static void test() {
+  int x; // expected-warning {{unused}}
+  B b;
+}
+
+#endif