1 files changed, 32 insertions, 20 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 10103708384..9c7126d9266 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -8619,6 +8619,29 @@ static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
   return false;
 }
 
+/// Common checks for whether an explicit instantiation of \p D is valid.
+static bool CheckExplicitInstantiation(Sema &S, NamedDecl *D,
+                                       SourceLocation InstLoc,
+                                       bool WasQualifiedName,
+                                       TemplateSpecializationKind TSK) {
+  // C++ [temp.explicit]p13:
+  //   An explicit instantiation declaration shall not name a specialization of
+  //   a template with internal linkage.
+  if (TSK == TSK_ExplicitInstantiationDeclaration &&
+      D->getFormalLinkage() == InternalLinkage) {
+    S.Diag(InstLoc, diag::err_explicit_instantiation_internal_linkage) << D;
+    return true;
+  }
+
+  // C++11 [temp.explicit]p3: [DR 275]
+  //   An explicit instantiation shall appear in an enclosing namespace of its
+  //   template.
+  if (CheckExplicitInstantiationScope(S, D, InstLoc, WasQualifiedName))
+    return true;
+
+  return false;
+}
+
 /// Determine whether the given scope specifier has a template-id in it.
 static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
   if (!SS.isSet())
@@ -8770,13 +8793,8 @@ DeclResult Sema::ActOnExplicitInstantiation(
   TemplateSpecializationKind PrevDecl_TSK
     = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
 
-  // C++0x [temp.explicit]p2:
-  //   [...] An explicit instantiation shall appear in an enclosing
-  //   namespace of its template. [...]
-  //
-  // This is C++ DR 275.
-  if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
-                                      SS.isSet()))
+  if (CheckExplicitInstantiation(*this, ClassTemplate, TemplateNameLoc,
+                                 SS.isSet(), TSK))
     return true;
 
   ClassTemplateSpecializationDecl *Specialization = nullptr;
@@ -8999,12 +9017,7 @@ Sema::ActOnExplicitInstantiation(Scope *S, SourceLocation ExternLoc,
     = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
                            : TSK_ExplicitInstantiationDeclaration;
 
-  // C++0x [temp.explicit]p2:
-  //   [...] An explicit instantiation shall appear in an enclosing
-  //   namespace of its template. [...]
-  //
-  // This is C++ DR 275.
-  CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
+  CheckExplicitInstantiation(*this, Record, NameLoc, true, TSK);
 
   // Verify that it is okay to explicitly instantiate here.
   CXXRecordDecl *PrevDecl
@@ -9235,8 +9248,7 @@ DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
            diag::ext_explicit_instantiation_without_qualified_id)
         << Prev << D.getCXXScopeSpec().getRange();
 
-    // Check the scope of this explicit instantiation.
-    CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
+    CheckExplicitInstantiation(*this, Prev, D.getIdentifierLoc(), true, TSK);
 
     // Verify that it is okay to explicitly instantiate here.
     TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
@@ -9444,11 +9456,11 @@ DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
          diag::ext_explicit_instantiation_without_qualified_id)
     << Specialization << D.getCXXScopeSpec().getRange();
 
-  CheckExplicitInstantiationScope(*this,
-                   FunTmpl? (NamedDecl *)FunTmpl
-                          : Specialization->getInstantiatedFromMemberFunction(),
-                                  D.getIdentifierLoc(),
-                                  D.getCXXScopeSpec().isSet());
+  CheckExplicitInstantiation(
+      *this,
+      FunTmpl ? (NamedDecl *)FunTmpl
+              : Specialization->getInstantiatedFromMemberFunction(),
+      D.getIdentifierLoc(), D.getCXXScopeSpec().isSet(), TSK);
 
   // FIXME: Create some kind of ExplicitInstantiationDecl here.
   return (Decl*) nullptr;