As a first step towards fixing PR9641, add a CK_DynamicToNull cast kind which

represents a dynamic cast where we know that the result is always null.

For example:

struct A {
  virtual ~A();
};
struct B final : A { };
struct C { };

bool f(B* b) {
  return dynamic_cast<C*>(b);
}

llvm-svn: 129256

1 files changed, 1 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 0a7f1e93af1..6a7637097b0 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -2178,6 +2178,7 @@ void ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex,
       // Various C++ casts that are not handled yet.
       case CK_ResolveUnknownAnyType:
       case CK_Dynamic:
+      case CK_DynamicToNull:
       case CK_ToUnion:
       case CK_BaseToDerived:
       case CK_NullToMemberPointer: