[analyzer] dynamic_cast: Better model cast from a reference.

Generate a sink when the dynamic_cast from a reference fails to
represent a thrown exception.

llvm-svn: 154438

1 files changed, 10 insertions, 2 deletions

diff --git a/clang/test/Analysis/dynamic-cast.cpp b/clang/test/Analysis/dynamic-cast.cpp
index 0d0c80fc120..8d1fde8cc5c 100644
--- a/clang/test/Analysis/dynamic-cast.cpp
+++ b/clang/test/Analysis/dynamic-cast.cpp
@@ -167,10 +167,18 @@ int testCastToVoidStar() {
   return *res; // no warning
 }
 
-int testReference() {
+int testReferenceSuccesfulCast() {
+  B rb;
+  B &b = dynamic_cast<B&>(rb);
+  int *x = 0;
+  return *x; // expected-warning {{Dereference of null pointer}}
+}
+
+int testReferenceFailedCast() {
   A a;
   B &b = dynamic_cast<B&>(a);
-  return b.m; // no warning
+  int *x = 0;
+  return *x; // no warning (An exception is thrown by the cast.)
 }
 
 // False negatives.