Check that the alias points to a valid namespace.

llvm-svn: 67925

clang/lib/Sema/SemaDeclCXX.cpp

@@ -1627,6 +1627,7 @@ Sema::DeclTy *Sema::ActOnUsingDirective(Scope *S,
   // Lookup namespace name.
   LookupResult R = LookupParsedName(S, &SS, NamespcName,
                                     LookupNamespaceName, false);
+  // FIXME: Can the result of a namespace lookup ever be ambiguous?
   if (R.isAmbiguous()) {
     DiagnoseAmbiguousLookup(R, NamespcName, IdentLoc);
     return 0;
@@ -1693,6 +1694,20 @@ Sema::DeclTy *Sema::ActOnNamespaceAliasDef(Scope *S,
     return 0;
   }
 
+  // Lookup the namespace name.
+  LookupResult R = LookupParsedName(S, &SS, NamespaceName,
+                                    LookupNamespaceName, false);
+  // FIXME: Can the result of a namespace lookup ever be ambiguous?
+  if (R.isAmbiguous()) {
+    DiagnoseAmbiguousLookup(R, NamespaceName, NamespaceLoc);
+    return 0;
+  }
+  
+  if (!R) {
+    Diag(NamespaceLoc, diag::err_expected_namespace_name) << SS.getRange();
+    return 0;
+  }
+  
   return 0;
 }
 

clang/test/SemaCXX/namespace-alias.cpp

@@ -9,3 +9,8 @@ namespace B = N; // expected-error {{redefinition of 'B' as different kind of sy
 
 namespace C { } // expected-note {{previous definition is here}}
 namespace C = N; // expected-error {{redefinition of 'C'}}
+
+int i;
+namespace D = i; // expected-error {{expected namespace name}}
+
+namespace E = N::Foo; // expected-error {{expected namespace name}}