r221160 - Don't allow dllimport/export on classes with internal linkage (PR21399)

[Hans Wennborg]

Author: hans
Date: Mon Nov  3 10:09:16 2014
New Revision: 221160

URL: http://llvm.org/viewvc/llvm-project?rev=221160&view=rev
Log:
Don't allow dllimport/export on classes with internal linkage (PR21399)

Trying to import or export such classes doesn't make sense, and Clang
would assert trying to export vtables for them.

This is consistent with how we treat functions with internal linkage,
but it is stricter than MSVC so we may have to back down if it breaks
real code.

Modified:
    cfe/trunk/lib/Sema/SemaDeclCXX.cpp
    cfe/trunk/test/SemaCXX/dllexport.cpp
    cfe/trunk/test/SemaCXX/dllimport.cpp

Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=221160&r1=221159&r2=221160&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Mon Nov  3 10:09:16 2014
@@ -4633,6 +4633,12 @@ static void checkDLLAttribute(Sema &S, C
   if (!ClassAttr)
     return;
 
+  if (!Class->isExternallyVisible()) {
+    S.Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
+        << Class << ClassAttr;
+    return;
+  }
+
   if (S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
       !ClassAttr->isInherited()) {
     // Diagnose dll attributes on members of class with dll attribute.

Modified: cfe/trunk/test/SemaCXX/dllexport.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/dllexport.cpp?rev=221160&r1=221159&r2=221160&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/dllexport.cpp (original)
+++ cfe/trunk/test/SemaCXX/dllexport.cpp Mon Nov  3 10:09:16 2014
@@ -327,6 +327,10 @@ template<> __declspec(dllexport) inline
 // Classes
 //===----------------------------------------------------------------------===//
 
+namespace {
+  struct __declspec(dllexport) AnonymousClass {}; // expected-error{{(anonymous namespace)::AnonymousClass' must have external linkage when declared 'dllexport'}}
+}
+
 class __declspec(dllexport) ClassDecl;
 
 class __declspec(dllexport) ClassDef {};

Modified: cfe/trunk/test/SemaCXX/dllimport.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/dllimport.cpp?rev=221160&r1=221159&r2=221160&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/dllimport.cpp (original)
+++ cfe/trunk/test/SemaCXX/dllimport.cpp Mon Nov  3 10:09:16 2014
@@ -1197,6 +1197,10 @@ template<typename T> template<typename U
 // Classes
 //===----------------------------------------------------------------------===//
 
+namespace {
+  struct __declspec(dllimport) AnonymousClass {}; // expected-error{{(anonymous namespace)::AnonymousClass' must have external linkage when declared 'dllimport'}}
+}
+
 class __declspec(dllimport) ClassDecl;
 
 class __declspec(dllimport) ClassDef { };