[modules] Support for merging a parsed class template specialization definition into an imported but hidden definition.

llvm-svn: 237612

2 files changed, 13 insertions, 3 deletions

diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index bb7ae63764a..07fd4742cd5 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -1640,7 +1640,8 @@ void Parser::ParseClassSpecifier(tok::TokenKind TagTokKind,
           *TemplateId, attrs.getList(),
           MultiTemplateParamsArg(TemplateParams ? &(*TemplateParams)[0]
                                                 : nullptr,
-                                 TemplateParams ? TemplateParams->size() : 0));
+                                 TemplateParams ? TemplateParams->size() : 0),
+          &SkipBody);
     }
   } else if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation &&
              TUK == Sema::TUK_Declaration) {
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 687e6111f2d..5319836c249 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -6052,7 +6052,9 @@ Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
                                        SourceLocation ModulePrivateLoc,
                                        TemplateIdAnnotation &TemplateId,
                                        AttributeList *Attr,
-                               MultiTemplateParamsArg TemplateParameterLists) {
+                                       MultiTemplateParamsArg
+                                           TemplateParameterLists,
+                                       SkipBodyInfo *SkipBody) {
   assert(TUK != TUK_Reference && "References are not specializations");
 
   CXXScopeSpec &SS = TemplateId.SS;
@@ -6363,7 +6365,14 @@ Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
 
   // Check that this isn't a redefinition of this specialization.
   if (TUK == TUK_Definition) {
-    if (RecordDecl *Def = Specialization->getDefinition()) {
+    RecordDecl *Def = Specialization->getDefinition();
+    NamedDecl *Hidden = nullptr;
+    if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
+      SkipBody->ShouldSkip = true;
+      makeMergedDefinitionVisible(Hidden, KWLoc);
+      // From here on out, treat this as just a redeclaration.
+      TUK = TUK_Declaration;
+    } else if (Def) {
       SourceRange Range(TemplateNameLoc, RAngleLoc);
       Diag(TemplateNameLoc, diag::err_redefinition)
         << Context.getTypeDeclType(Specialization) << Range;