[clang][MSVC] Fix missing MSInheritanceAttr in template specialization.

[zequanwu]

Summary

Fix PR48687.

[zequanwu]

clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp

151–159

I tried to put the following CHECK for this, it never works no matter where I put namespace pr48687 nor changing CHECK to CHECK-DAG works.
// CHECK: @"?address@?$A@M@pr48687@@2QQ12@MQ12@" = weak_odr dso_local constant i32 0, comdat, align 1

So, as long as it does not crash/error, it might be fine.

[zequanwu]

Update test case.

[zequanwu]

clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp

151–159

NVM, the align should be 4.

[rnk]

Thanks, this seems like the right spot.

clang/lib/Sema/SemaTemplate.cpp

9767

Let's remove this condition. There will only ever be inheritance attributes when the MS ABI is in use. I think fewer conditions is usually better.

clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp

151–159

I see you sorted this out, thanks. I was going to suggest moving it earlier. Clang produces globals in a bit of an odd order.

[zequanwu]

Address comment.

[rnk]

lgtm

clang/lib/Sema/SemaTemplate.cpp

if (Def) {
     // In MinGW mode, export the template instantiation if the declaration
     // was marked dllexport.
     if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
         Context.getTargetInfo().getTriple().isWindowsGNUEnvironment() &&
         PrevDecl->hasAttr<DLLExportAttr>()) {
       dllExportImportClassTemplateSpecialization(*this, Def);
     }
 
+    if (Def->hasAttr<MSInheritanceAttr>()) {
+      Specialization->addAttr(Def->getAttr<MSInheritanceAttr>());
+      Consumer.AssignInheritanceModel(Specialization);
+    }
+
     // Set the template specialization kind. Make sure it is set before
     // instantiating the members which will trigger ASTConsumer callbacks.
     Specialization->setTemplateSpecializationKind(TSK);
     InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
   } else {
 
     // Set the template specialization kind.
     Specialization->setTemplateSpecializationKind(TSK);

clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp

 };
 
 // CHECK: @"?table@pr43803@@3QBUC@1@B" = dso_local constant [3 x %"struct.pr43803::C"]
 // CHECK-SAME: [%"struct.pr43803::C" { { i32, i32, i32 } zeroinitializer, [4 x i8] undef },
 // CHECK-SAME:  %"struct.pr43803::C" { { i32, i32, i32 } { i32 4, i32 0, i32 0 }, [4 x i8] undef },
 // CHECK-SAME:  %"struct.pr43803::C" { { i32, i32, i32 } { i32 8, i32 0, i32 0 }, [4 x i8] undef }]
 }
 
+namespace pr48687 {
+template <typename T> struct A {
+  T value;
+  static constexpr auto address = &A<T>::value;
+};
+extern template class A<float>;
+template class A<float>;
+// CHECK: @"?address@?$A@M@pr48687@@2QQ12@MQ12@" = weak_odr dso_local constant i32 0, comdat, align 4
+}
+
 struct PR26313_Y;
 typedef void (PR26313_Y::*PR26313_FUNC)();
 struct PR26313_X {
   PR26313_FUNC *ptr;
   PR26313_X();
 };
 PR26313_X::PR26313_X() {}
 void PR26313_f(PR26313_FUNC *p) { delete p; }