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git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67776 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/PathDiagnostic.cpp b/lib/Analysis/PathDiagnostic.cpp
index d719aa8..1441088 100644
--- a/lib/Analysis/PathDiagnostic.cpp
+++ b/lib/Analysis/PathDiagnostic.cpp
@@ -140,6 +140,8 @@
 //===----------------------------------------------------------------------===//
 
 FullSourceLoc PathDiagnosticLocation::asLocation() const {
+  // Note that we want a 'switch' here so that the compiler can warn us in
+  // case we add more cases.
   switch (K) {
     case SingleLoc:
     case Range: