[c++2a] Allow comparison functions to be explicitly defaulted.

This adds some initial syntactic checking that only the appropriate
function signatures can be defaulted. No implicit definitions are
generated yet.

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index d1ad304e62e..31a4302ba82 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2049,6 +2049,11 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
     }
   }
 
+  if (D->isExplicitlyDefaulted())
+    SemaRef.SetDeclDefaulted(Function, D->getLocation());
+  if (D->isDeleted())
+    SemaRef.SetDeclDeleted(Function, D->getLocation());
+
   if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
     DC->makeDeclVisibleInContext(PrincipalDecl);
 
@@ -2056,7 +2061,6 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
       PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
     PrincipalDecl->setNonMemberOperator();
 
-  assert(!D->isDefaulted() && "only methods should be defaulted");
   return Function;
 }
 
@@ -4016,9 +4020,6 @@ void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
 bool
 TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
                                                     FunctionDecl *Tmpl) {
-  if (Tmpl->isDeleted())
-    New->setDeletedAsWritten();
-
   New->setImplicit(Tmpl->isImplicit());
 
   // Forward the mangling number from the template to the instantiated decl.