[modules] Handle defining a class template on top of an existing imported-but-not-visible definition.

llvm-svn: 233341

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index ffd22390ee3..e9c40aa2e5d 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11297,7 +11297,8 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
                                                ModulePrivateLoc,
                                                /*FriendLoc*/SourceLocation(),
                                                TemplateParameterLists.size()-1,
-                                               TemplateParameterLists.data());
+                                               TemplateParameterLists.data(),
+                                               SkipBody);
         return Result.get();
       } else {
         // The "template<>" header is extraneous.
@@ -11696,8 +11697,9 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
                     TSK_ExplicitSpecialization;
               }
 
+              NamedDecl *Hidden = nullptr;
               if (SkipBody && getLangOpts().CPlusPlus &&
-                  !hasVisibleDefinition(Def, &Def)) {
+                  !hasVisibleDefinition(Def, &Hidden)) {
                 // There is a definition of this tag, but it is not visible. We
                 // explicitly make use of C++'s one definition rule here, and
                 // assume that this definition is identical to the hidden one
@@ -11705,8 +11707,8 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
                 // use it in place of this one.
                 *SkipBody = true;
                 if (auto *Listener = getASTMutationListener())
-                  Listener->RedefinedHiddenDefinition(Def, KWLoc);
-                Def->setHidden(false);
+                  Listener->RedefinedHiddenDefinition(Hidden, KWLoc);
+                Hidden->setHidden(false);
                 return Def;
               } else if (!IsExplicitSpecializationAfterInstantiation) {
                 // A redeclaration in function prototype scope in C isn't