When we know that a dynamic_cast always returns null, we can make
CodeGenFunction::EmitDynamicCast always return null or throw a bad_cast
exception.
llvm-svn: 129264
diff --git a/clang/test/CodeGenCXX/dynamic-cast-always-null.cpp b/clang/test/CodeGenCXX/dynamic-cast-always-null.cpp
new file mode 100644
index 0000000..48ec692
--- /dev/null
+++ b/clang/test/CodeGenCXX/dynamic-cast-always-null.cpp
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -I%S %s -triple x86_64-apple-darwin10 -emit-llvm -fcxx-exceptions -fexceptions -std=c++0x -o - | FileCheck %s
+struct A { virtual ~A(); };
+struct B final : A { };
+struct C { virtual ~C(); };
+
+// CHECK: @_Z1fP1B
+C *f(B* b) {
+ // CHECK-NOT: call i8* @__dynamic_cast
+ // CHECK: ret %struct.C* null
+ return dynamic_cast<C*>(b);
+}
+
+// CHECK: @_Z1fR1B
+C &f(B& b) {
+ // CHECK-NOT: call i8* @__dynamic_cast
+ // CHECK: call void @__cxa_bad_cast() noreturn
+ // CHECK: ret %struct.C* undef
+ return dynamic_cast<C&>(b);
+}