Diagnose use of a naked attribute on a member function in ms-mode

This matches the behavior of cl.exe.

clang/docs/ReleaseNotes.rst

@@ -131,6 +131,9 @@ Attribute Changes in Clang
 
 - ``#pragma clang attribute push`` now supports multiple attributes within a single directive.
 
+- The ``__declspec(naked)`` attribute can no longer be written on a member
+  function in Microsoft compatibility mode, matching the behavior of cl.exe.
+
 Windows Support
 ---------------
 

clang/lib/Sema/SemaDeclAttr.cpp

@@ -2158,6 +2158,14 @@ static void handleNakedAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
           << AL << Triple.getArchName();
       return;
     }
+
+    // This form is not allowed to be written on a member function (static or
+    // nonstatic) when in Microsoft compatibility mode.
+    if (S.getLangOpts().MSVCCompat && isa<CXXMethodDecl>(D)) {
+      S.Diag(AL.getLoc(), diag::err_attribute_wrong_decl_type_str)
+          << AL << "non-member functions";
+      return;
+    }
   }
 
   D->addAttr(::new (S.Context) NakedAttr(S.Context, AL));

clang/test/Sema/attr-naked.cpp

@@ -1,4 +1,6 @@
 // RUN: %clang_cc1 %s -verify -fsyntax-only -triple arm-none-linux
+// RUN: %clang_cc1 %s -verify -fsyntax-only -fms-compatibility -DDECLSPEC -triple i686-pc-win32
+
 class Foo {
   void bar();
   static void bar2();
@@ -13,3 +15,12 @@ void __attribute__((naked)) Foo::bar() { // expected-note{{attribute is here}}
 void __attribute__((naked)) Foo::bar2() {
   asm("mov r2, %0" : : "r"(s)); // static member reference is OK
 }
+
+struct Bar {
+#ifdef DECLSPEC
+  __declspec(naked) void func1(); // expected-error {{'naked' attribute only applies to non-member functions}}
+  __declspec(naked) static void func2(); // expected-error {{'naked' attribute only applies to non-member functions}}
+#endif
+  __attribute__((naked)) void func3(); // OK
+  __attribute__((naked)) static void func4(); // OK
+};