For dllexport class templates, export specializations of member functions (PR34849) (take 2)

This is a re-commit of r315025, but making sure to only apply this to
specializations of class template member functions; i.e. not when the function
itself is a template.

llvm-svn: 315330

1 files changed, 16 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 78ceeedc3ac..541cf693b63 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6041,6 +6041,22 @@ static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
            diag::warn_dllimport_dropped_from_inline_function)
         << NewDecl << OldImportAttr;
   }
+
+  // A specialization of a class template member function is processed here
+  // since it's a redeclaration. If the parent class is dllexport, the
+  // specialization inherits that attribute. This doesn't happen automatically
+  // since the parent class isn't instantiated until later.
+  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDecl)) {
+    if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization &&
+        !NewImportAttr && !NewExportAttr) {
+      if (const DLLExportAttr *ParentExportAttr =
+              MD->getParent()->getAttr<DLLExportAttr>()) {
+        DLLExportAttr *NewAttr = ParentExportAttr->clone(S.Context);
+        NewAttr->setInherited(true);
+        NewDecl->addAttr(NewAttr);
+      }
+    }
+  }
 }
 
 /// Given that we are within the definition of the given function,