[UBSan] Introduce type-based blacklisting.

Teach UBSan vptr checker to ignore technically invalud down-casts on
blacklisted types.

Based on http://reviews.llvm.org/D4407 by Byoungyoung Lee!

llvm-svn: 212770

1 files changed, 25 insertions, 0 deletions

diff --git a/clang/test/CodeGen/ubsan-type-blacklist.cpp b/clang/test/CodeGen/ubsan-type-blacklist.cpp
new file mode 100644
index 00000000000..7dc6fe159b5
--- /dev/null
+++ b/clang/test/CodeGen/ubsan-type-blacklist.cpp
@@ -0,0 +1,25 @@
+// Verify ubsan vptr does not check down-casts on blacklisted types.
+// RUN: echo "type:_ZTI3Foo" > %t-type.blacklist
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsanitize=vptr -emit-llvm %s -o - | FileCheck %s --check-prefix=DEFAULT
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsanitize=vptr -fsanitize-blacklist=%t-type.blacklist -emit-llvm %s -o - | FileCheck %s --check-prefix=TYPE
+
+// REQUIRES: shell
+
+class Bar {
+public:
+  virtual ~Bar() {}
+};
+class Foo : public Bar {};
+
+Bar bar;
+
+// DEFAULT: @_Z7checkmev
+// TYPE: @_Z7checkmev
+void checkme() {
+// DEFAULT: call void @__ubsan_handle_dynamic_type_cache_miss({{.*}} (%class.Bar* @bar to
+// TYPE-NOT: @__ubsan_handle_dynamic_type_cache_miss
+  Foo* foo = static_cast<Foo*>(&bar); // down-casting
+// DEFAULT: ret void
+// TYPE: ret void
+  return;
+}