2 files changed, 50 insertions, 0 deletions
diff --git a/clang/unittests/Basic/CMakeLists.txt b/clang/unittests/Basic/CMakeLists.txt
index b8f69bf357b..3cb3cb8d3c8 100644
--- a/clang/unittests/Basic/CMakeLists.txt
+++ b/clang/unittests/Basic/CMakeLists.txt
@@ -4,6 +4,7 @@ set(LLVM_LINK_COMPONENTS
 
 add_clang_unittest(BasicTests
   CharInfoTest.cpp
+  DiagnosticTest.cpp
   FileManagerTest.cpp
   SourceManagerTest.cpp
   VirtualFileSystemTest.cpp
diff --git a/clang/unittests/Basic/DiagnosticTest.cpp b/clang/unittests/Basic/DiagnosticTest.cpp
new file mode 100644
index 00000000000..fa2b56e0834
--- /dev/null
+++ b/clang/unittests/Basic/DiagnosticTest.cpp
@@ -0,0 +1,49 @@
+//===- unittests/Basic/DiagnosticTest.cpp -- Diagnostic engine tests ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticIDs.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace clang;
+
+namespace {
+
+// Check that DiagnosticErrorTrap works with SuppressAllDiagnostics.
+TEST(DiagnosticTest, suppressAndTrap) {
+  DiagnosticsEngine Diags(new DiagnosticIDs(),
+                          new DiagnosticOptions,
+                          new IgnoringDiagConsumer());
+  Diags.setSuppressAllDiagnostics(true);
+
+  {
+    DiagnosticErrorTrap trap(Diags);
+
+    // Diag that would set UncompilableErrorOccurred and ErrorOccurred.
+    Diags.Report(diag::err_target_unknown_triple) << "unknown";
+
+    // Diag that would set UnrecoverableErrorOccurred and ErrorOccurred.
+    Diags.Report(diag::err_cannot_open_file) << "file" << "error";
+
+    // Diag that would set FatalErrorOccurred
+    // (via non-note following a fatal error).
+    Diags.Report(diag::warn_mt_message) << "warning";
+
+    EXPECT_TRUE(trap.hasErrorOccurred());
+    EXPECT_TRUE(trap.hasUnrecoverableErrorOccurred());
+  }
+
+  EXPECT_FALSE(Diags.hasErrorOccurred());
+  EXPECT_FALSE(Diags.hasFatalErrorOccurred());
+  EXPECT_FALSE(Diags.hasUncompilableErrorOccurred());
+  EXPECT_FALSE(Diags.hasUnrecoverableErrorOccurred());
+}
+
+}