Re-commit r270748 "clang-cl: Treat dllimport explicit template instantiation definitions as declarations (PR27810, PR27811)"

Also make explicit instantiation decls not apply to nested classes when
targeting MSVC. That dll attributes are not inherited by inner classes
might be the explanation for MSVC's behaviour here.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@270897 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 8 deletions

diff --git a/test/CodeGenCXX/dllexport.cpp b/test/CodeGenCXX/dllexport.cpp
index 6232f2c747..7cef7c2d12 100644
--- a/test/CodeGenCXX/dllexport.cpp
+++ b/test/CodeGenCXX/dllexport.cpp
@@ -844,6 +844,11 @@ struct __declspec(dllexport) B {
 // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01??_FB@pr26490@@QAEXXZ"
 }
 
+// dllexport trumps dllexport on an explicit instantiation.
+template <typename T> struct ExplicitInstantiationTwoAttributes { void f() {} };
+template struct __declspec(dllexport) __declspec(dllimport) ExplicitInstantiationTwoAttributes<int>;
+// M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?f@?$ExplicitInstantiationTwoAttributes@H@@QAEXXZ"
+
 
 //===----------------------------------------------------------------------===//
 // Classes with template base classes
@@ -958,14 +963,6 @@ template struct ExplicitInstantiationDeclTemplateBase<int>;
 // M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?func@?$ExplicitInstantiationDeclTemplateBase@H@@QAEXXZ"
 // G32-DAG: define weak_odr x86_thiscallcc void @_ZN37ExplicitInstantiationDeclTemplateBaseIiE4funcEv
 
-template <typename T> struct ExplicitInstantiationDeclTemplateBase2 { void func() {} };
-extern template struct ExplicitInstantiationDeclTemplateBase2<int>;
-struct __declspec(dllexport) DerivedFromExplicitInstantiationDeclTemplateBase2 : public ExplicitInstantiationDeclTemplateBase2<int> {};
-template struct __declspec(dllimport) ExplicitInstantiationDeclTemplateBase2<int>;
-USEMEMFUNC(ExplicitInstantiationDeclTemplateBase2<int>, func)
-// M32-DAG: define weak_odr dllexport x86_thiscallcc void @"\01?func@?$ExplicitInstantiationDeclTemplateBase2@H@@QAEXXZ"
-// G32-DAG: define weak_odr x86_thiscallcc void @_ZN38ExplicitInstantiationDeclTemplateBase2IiE4funcEv
-
 // PR26076
 struct LayerSelectionBound;
 template <typename> struct Selection {};