-fsanitize=vptr warnings on bad static types in dynamic_cast and typeid

...when such an operation is done on an object during con-/destruction.

This is the cfe part of a patch covering both cfe and compiler-rt.

Differential Revision: https://reviews.llvm.org/D40295

llvm-svn: 321519

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/ubsan-vtable-checks.cpp b/clang/test/CodeGenCXX/ubsan-vtable-checks.cpp
index 5e17913a2c8..090707c29d7 100644
--- a/clang/test/CodeGenCXX/ubsan-vtable-checks.cpp
+++ b/clang/test/CodeGenCXX/ubsan-vtable-checks.cpp
@@ -38,3 +38,15 @@ void delete_it(T *t) {
   // CHECK-VPTR: load {{.*}} (%struct.T*{{.*}})**, {{.*}} (%struct.T*{{.*}})***
   delete t;
 }
+
+// ITANIUM: define %struct.U* @_Z7dyncastP1T
+// MSABI: define %struct.U* @"\01?dyncast
+U* dyncast(T *t) {
+  // First, we check that dynamic_cast is not called before a type check.
+  // CHECK-VPTR-NOT: call i8* @__{{dynamic_cast|RTDynamicCast}}
+  // CHECK-VPTR: br i1 {{.*}} label %{{.*}}
+  // CHECK-VPTR: call void @__ubsan_handle_dynamic_type_cache_miss_abort
+  // Second, we check that dynamic_cast is actually called once the type check is done.
+  // CHECK-VPTR: call i8* @__{{dynamic_cast|RTDynamicCast}}
+  return dynamic_cast<U*>(t);
+}