Rough fix for PR9323 that prevents Clang from marking copy constructor

declarations as referenced when in fact we're not going to even form
a call in the AST. This is significant because we attempt to allow as an
extension classes with intentionally private and undefined copy
constructors to have temporaries bound to references, and so shouldn't
warn about the lack of definition for that copy constructor when the
class is internal.

Doug, John wasn't really satisfied with the presence of overloading at
all. This is a stop-gap and there may be a better solution. If you can
give me some hints for how you'd prefer to see this solved, I'll happily
switch things over.

llvm-svn: 126480

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/undefined-internal.cpp b/clang/test/SemaCXX/undefined-internal.cpp
index a7e92499657..e926f18d5ff 100644
--- a/clang/test/SemaCXX/undefined-internal.cpp
+++ b/clang/test/SemaCXX/undefined-internal.cpp
@@ -105,3 +105,20 @@ namespace test6 {
     a.value = A<Internal>::two;
   }
 }
+
+// We support (as an extension) private, undefined copy constructors when
+// a temporary is bound to a reference even in C++98. Similarly, we shouldn't
+// warn about this copy constructor being used without a definition.
+namespace PR9323 {
+  namespace {
+    struct Uncopyable {
+      Uncopyable() {}
+    private:
+      Uncopyable(const Uncopyable&); // expected-note {{declared private here}}
+    };
+  }
+  void f(const Uncopyable&) {}
+  void test() {
+    f(Uncopyable()); // expected-warning {{C++98 requires an accessible copy constructor}}
+  };
+}