2 files changed, 32 insertions, 2 deletions
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d26e5e18830..c908f672a4f 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6002,6 +6002,15 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
         NewVD->setInvalidDecl(true);
       }
 
+      // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
+      // applied only to the definition of a function template or variable
+      // template, declared in namespace scope.
+      if (IsVariableTemplateSpecialization) {
+        Diag(D.getDeclSpec().getConceptSpecLoc(),
+             diag::err_concept_specified_specialization)
+            << (IsPartialSpecialization ? 2 : 1);
+      }
+
       // C++ Concepts TS [dcl.spec.concept]p6: A variable concept has the
       // following restrictions:
       // - The declared type shall have the type bool.
@@ -7667,6 +7676,10 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     }
 
     if (isConcept) {
+      // This is a function concept.
+      if (FunctionTemplateDecl *FTD = NewFD->getDescribedFunctionTemplate())
+        FTD->setConcept();
+
       // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
       // applied only to the definition of a function template [...]
       if (!D.isFunctionDefinition()) {
@@ -7733,6 +7746,14 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
             << 1 << 3;
         NewFD->setInvalidDecl(true);
       }
+
+      // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
+      // applied only to the definition of a function template or variable
+      // template, declared in namespace scope.
+      if (isFunctionTemplateSpecialization) {
+        Diag(D.getDeclSpec().getConceptSpecLoc(),
+             diag::err_concept_specified_specialization) << 1;
+      }
     }
 
     // If __module_private__ was specified, mark the function accordingly.
@@ -7994,9 +8015,9 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
                                          TemplateId->NumArgs);
       translateTemplateArguments(TemplateArgsPtr,
                                  TemplateArgs);
-    
+
       HasExplicitTemplateArgs = true;
-    
+
       if (NewFD->isInvalidDecl()) {
         HasExplicitTemplateArgs = false;
       } else if (FunctionTemplate) {
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 878243932c8..8efdba87f5b 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -7673,6 +7673,15 @@ DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
     Diag(D.getDeclSpec().getConstexprSpecLoc(),
          diag::err_explicit_instantiation_constexpr);
 
+  // C++ Concepts TS [dcl.spec.concept]p1: The concept specifier shall be
+  // applied only to the definition of a function template or variable template,
+  // declared in namespace scope.
+  if (D.getDeclSpec().isConceptSpecified()) {
+    Diag(D.getDeclSpec().getConceptSpecLoc(),
+         diag::err_concept_specified_specialization) << 0;
+    return true;
+  }
+
   // C++0x [temp.explicit]p2:
   //   There are two forms of explicit instantiation: an explicit instantiation
   //   definition and an explicit instantiation declaration. An explicit