PR13273: When performing list-initialization with an empty initializer list,

actually perform value initialization rather than trying to fake it with a call
to the default constructor. Fixes various bugs related to the previously-missing
zero-initialization in this case.

I've also moved this and the other list initialization 'special case' from
TryConstructorInitialization into TryListInitialization where they belong.

llvm-svn: 159733

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/constructor-init.cpp b/clang/test/CodeGenCXX/constructor-init.cpp
index 9f808f6680e..b33184e3966 100644
--- a/clang/test/CodeGenCXX/constructor-init.cpp
+++ b/clang/test/CodeGenCXX/constructor-init.cpp
@@ -131,6 +131,26 @@ namespace rdar9694300 {
   }
 }
 
+// Check that we emit a zero initialization step for list-value-initialization
+// which calls a trivial default constructor.
+namespace PR13273 {
+  struct U {
+    int t;
+    U() = default;
+  };
+
+  struct S : U {
+    S() = default;
+  };
+
+  // CHECK: define {{.*}}@_ZN7PR132731fEv(
+  int f() {
+    // CHECK-NOT: }
+    // CHECK: llvm.memset{{.*}}i8 0
+    return (new S{})->t;
+  }
+}
+
 template<typename T>
 struct X {
   X(const X &);