mingw-w64: enable support for __declspec(selectany)

[martell]

@rnk what are your thoughts on adding a new LangOpts maybe called WindowsExt which can be shared across MSVC and Mingw?
I will also add a test case once I know how best to proceed

[martell]

updated to fix test cases.

needs more work,
I see that I can have an array of language opts so I will add a mingw one rather then a combined one

[rnk]

Using TargetSpecificAttr<TargetWindws> sounds good to me.

include/clang/Basic/Attr.td

2245 ↗

(On Diff #95305)

This is at least consistent with what we do for dllexport/dllimport, which is the other major attribute/declspec that GCC and MSVC share, so let's do that for now.

test/Sema/attr-selectany.c

2 ↗

(On Diff #95305)

Ditto, can we remove -fms-extensions?

test/SemaCXX/attr-selectany.cpp

1 ↗

(On Diff #95305)

Does the test still pass if you remove -fms-extensions? If it does, let's remove it to simplify the test.

[martell]

I got a little carried away and submitted too early before I realised they were comma separated arguments.

[martell]

test/Sema/attr-selectany.c

2 ↗

(On Diff #95305)

I done it in a way to work without -fms-extensions for mingw but not for masvc to keep the current expectation intact

test/SemaCXX/attr-selectany.cpp

1 ↗

(On Diff #95305)

Ditto

[martell]

Also note that now we have to add the target to non msvc default hosts.
The test case was updated to reflect that.

[martell]

reverted back based on comments by @rnk

We can't just simply remove -fms-extensions because
'__declspec' attributes are not enabled; use '-fdeclspec' or '-fms-extensions' to enable support for __declspec attributes
mingw passes -fdeclspec.

Test cases are updated to test both -fdeclspec and -fms-extensions because the cpp testcase does a lot more then just test selectany

[rnk]

Thanks!

cfe/trunk/include/clang/Basic/Attr.td

 }
 
 def DLLImport : InheritableAttr, TargetSpecificAttr<TargetWindows> {
   let Spellings = [Declspec<"dllimport">, GCC<"dllimport">];
   let Subjects = SubjectList<[Function, Var, CXXRecord, ObjCInterface]>;
   let Documentation = [DLLImportDocs];
 }
 
-def SelectAny : InheritableAttr {
-  let Spellings = [Declspec<"selectany">];
-  let LangOpts = [MicrosoftExt];
+def SelectAny : InheritableAttr, TargetSpecificAttr<TargetWindows> {
+  let Spellings = [Declspec<"selectany">, GCC<"selectany">];
   let Documentation = [Undocumented];
 }
 
 def Thread : Attr {
   let Spellings = [Declspec<"thread">];
   let LangOpts = [MicrosoftExt];
   let Documentation = [ThreadDocs];
   let Subjects = SubjectList<[Var]>;

cfe/trunk/test/Sema/attr-selectany.c

-// RUN: %clang_cc1 -fms-compatibility -fms-extensions -verify %s
+// RUN: %clang_cc1 -triple x86_64-win32 -fdeclspec -verify %s
+// RUN: %clang_cc1 -triple x86_64-mingw32 -verify %s
 
 extern __declspec(selectany) const int x1 = 1; // no warning, const means we need extern in C++
 
 // Should we really warn on this?
 extern __declspec(selectany) int x2 = 1; // expected-warning {{'extern' variable has an initializer}}
 
 __declspec(selectany) void foo() { } // expected-error{{'selectany' can only be applied to data items with external linkage}}

cfe/trunk/test/SemaCXX/attr-selectany.cpp

-// RUN: %clang_cc1 -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s
+// RUN: %clang_cc1 -triple x86_64-win32 -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s
 // MSVC produces similar diagnostics.
 
 __declspec(selectany) void foo() { } // expected-error{{'selectany' can only be applied to data items with external linkage}}
 
 __declspec(selectany) int x1 = 1;
 
 const __declspec(selectany) int x2 = 2; // expected-error{{'selectany' can only be applied to data items with external linkage}}