Do not crash when we dynamic cast a final type to void*.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158763 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 8 insertions, 0 deletions

diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index e4545c152f..072e2ecdb4 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -553,6 +553,9 @@ bool CXXDynamicCastExpr::isAlwaysNull() const
     DestType = DestType->castAs<PointerType>()->getPointeeType();
   }
 
+  if (DestType->isVoidType())
+    return false;
+
   const CXXRecordDecl *SrcRD = 
     cast<CXXRecordDecl>(SrcType->castAs<RecordType>()->getDecl());
 
diff --git a/test/CodeGenCXX/dynamic-cast-always-null.cpp b/test/CodeGenCXX/dynamic-cast-always-null.cpp
index 2c3ea13d19..836cb110da 100644
--- a/test/CodeGenCXX/dynamic-cast-always-null.cpp
+++ b/test/CodeGenCXX/dynamic-cast-always-null.cpp
@@ -17,3 +17,8 @@ C &f(B& b) {
   // CHECK: ret %struct.C* undef
   return dynamic_cast<C&>(b);
 }
+
+void dont_crash() {
+  (void) dynamic_cast<void*>((A*)0);
+  (void) dynamic_cast<void*>((B*)0);
+}