Fix crash when handling an argument parsing-related warning.
Summary: Don't crash on warnings coming before the translation unit starts.
Reviewers: klimek, djasper
Reviewed By: djasper
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2676
llvm-svn: 200702
diff --git a/clang-tools-extra/test/clang-tidy/diagnostic.cpp b/clang-tools-extra/test/clang-tidy/diagnostic.cpp
new file mode 100644
index 0000000..e82f7d4
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/diagnostic.cpp
@@ -0,0 +1,5 @@
+// RUN: grep -Ev "// *[A-Z-]+:" %s > %t.cpp
+// RUN: clang-tidy %t.cpp -- -fan-unknown-option > %t2.cpp
+// RUN: FileCheck -input-file=%t2.cpp %s
+
+// CHECK: warning: unknown argument: '-fan-unknown-option'