Warning in Clang

/home/rengolin/workspace/llvm/rw/src/tools/clang/lib/CodeGen/CGExprConstant.cpp:
In member function
‘llvm::Constant*<unnamed>::ConstExprEmitter::VisitCastExpr(clang::CastExpr*)’:
/home/rengolin/workspace/llvm/rw/src/tools/clang/lib/CodeGen/CGExprConstant.cpp:621:
warning: control reaches end of non-void function

A switch without a default label or a return at the end.