When collecting virtual bases it's very important to use the canonical type of the base class. Otherwise, we might add the same virtual base class twice if the virtual base is an instantiated template. Fixes PR6251.

llvm-svn: 99829

1 files changed, 23 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/virtual-bases.cpp b/clang/test/CodeGenCXX/virtual-bases.cpp
index 62771757630..61de3153fd5 100644
--- a/clang/test/CodeGenCXX/virtual-bases.cpp
+++ b/clang/test/CodeGenCXX/virtual-bases.cpp
@@ -23,3 +23,26 @@ struct C : virtual A {
 // CHECK: define void @_ZN1CC1Eb(%struct.B* %this, i1 zeroext)
 // CHECK: define void @_ZN1CC2Eb(%struct.B* %this, i8** %vtt, i1 zeroext)
 C::C(bool) { }
+
+// PR6251
+namespace PR6251 {
+
+// Test that we don't call the A<char> constructor twice.
+
+template<typename T>
+struct A { A(); };
+
+struct B : virtual A<char> { };
+struct C : virtual A<char> { };
+
+struct D : B, C  {
+  D();
+};
+
+// CHECK: define void @_ZN6PR62511DC1Ev
+// CHECK: call void @_ZN6PR62511AIcEC2Ev
+// CHECK-NOT: call void @_ZN6PR62511AIcEC2Ev
+// CHECK: ret void
+D::D() { }
+
+}