[Sema] Correct IUnknown to support Unknwnbase.h Header.

Apparently, the MSVC SDK has a strange implementation that
causes a number of implicit functions as well as a template member
function of the IUnknown type. This patch allows these as InterfaceLike
types as well.

Additionally, it corrects the behavior where extern-C++ wrapped around an
Interface-Like type would permit an interface-like type to exist in a namespace.

Differential Revision: https://reviews.llvm.org/D38303

llvm-svn: 314557

2 files changed, 54 insertions, 4 deletions

diff --git a/clang/test/SemaCXX/ms-iunknown-template-function.cpp b/clang/test/SemaCXX/ms-iunknown-template-function.cpp
new file mode 100644
index 00000000000..dc192238fbd
--- /dev/null
+++ b/clang/test/SemaCXX/ms-iunknown-template-function.cpp
@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -fms-extensions %s 
+typedef long HRESULT;
+typedef unsigned long ULONG;
+typedef struct _GUID {
+  unsigned long Data1;
+  unsigned short Data2;
+  unsigned short Data3;
+  unsigned char Data4[8];
+} GUID;
+typedef GUID IID;
+
+// remove stdcall, since the warnings have nothing to do with
+// what is being tested.
+#define __stdcall
+
+extern "C" {
+extern "C++" {
+// expected-warning@+1 {{__declspec attribute 'novtable'}}
+struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) __declspec(novtable)
+    IUnknown {
+public:
+  virtual HRESULT __stdcall QueryInterface(
+      const IID &riid,
+      void **ppvObject) = 0;
+
+  virtual ULONG __stdcall AddRef(void) = 0;
+
+  virtual ULONG __stdcall Release(void) = 0;
+
+  template <class Q>
+  HRESULT __stdcall QueryInterface(Q **pp) {
+    return QueryInterface(__uuidof(Q), (void **)pp);
+  }
+};
+}
+}
+
+__interface ISfFileIOPropertyPage : public IUnknown{};
+
diff --git a/clang/test/SemaCXX/ms-iunknown.cpp b/clang/test/SemaCXX/ms-iunknown.cpp
index f73864d43fb..df761d56a80 100644
--- a/clang/test/SemaCXX/ms-iunknown.cpp
+++ b/clang/test/SemaCXX/ms-iunknown.cpp
@@ -2,7 +2,11 @@
 
 extern "C++" struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {
   void foo();
+  // Definitions aren't allowed, unless they are a template.
+  template<typename T>
+  void bar(T t){}
 };
+
 struct IPropertyPageBase : public IUnknown {};
 struct IPropertyPage : public IPropertyPageBase {};
 __interface ISfFileIOPropertyPage : public IPropertyPage {};
@@ -11,10 +15,17 @@ __interface ISfFileIOPropertyPage : public IPropertyPage {};
 namespace NS {
   struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {};
   // expected-error@+1 {{interface type cannot inherit from}}
-  __interface IPropertyPageBase : public IUnknown {}; 
+  __interface IPropertyPageBase : public IUnknown {};
 }
+
+namespace NS2 {
+extern "C++" struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {};
+// expected-error@+1 {{interface type cannot inherit from}}
+__interface IPropertyPageBase : public IUnknown{};
+}
+
 // expected-error@+1 {{interface type cannot inherit from}}
-__interface IPropertyPageBase2 : public NS::IUnknown {}; 
+__interface IPropertyPageBase2 : public NS::IUnknown {};
 
 __interface temp_iface {};
 struct bad_base : temp_iface {};
@@ -32,8 +43,8 @@ __interface PropertyPage : public Page4 {};
 
 struct Page5 : public Page3, Page4{};
 // expected-error@+1 {{interface type cannot inherit from}}
-__interface PropertyPage2 : public Page5 {}; 
+__interface PropertyPage2 : public Page5 {};
 
 __interface IF1 {};
-__interface PP : IUnknown, IF1{}; 
+__interface PP : IUnknown, IF1{};
 __interface PP2 : PP, Page3, Page4{};