Index: lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
===================================================================
--- lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
+++ lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionParser.cpp
@@ -857,8 +857,9 @@
   // To actually get the raw user input here, we have to cast our expression to
   // the LLVMUserExpression which exposes the right API. This should never fail
   // as we always have a ClangUserExpression whenever we call this.
-  LLVMUserExpression &llvm_expr = *static_cast<LLVMUserExpression *>(&m_expr);
-  CodeComplete CC(request, m_compiler->getLangOpts(), llvm_expr.GetUserText(),
+  ClangUserExpression *llvm_expr = dyn_cast<ClangUserExpression>(&m_expr);
+  assert(llvm_expr && "m_expr not an ClangUserExpression?");
+  CodeComplete CC(request, m_compiler->getLangOpts(), llvm_expr->GetUserText(),
                   typed_pos);
   // We don't need a code generator for parsing.
   m_code_generator.reset();