r256602 - When a namespace alias redeclares a using declaration, point the diagnostic at

[Richard Smith via cfe-commits]

Author: rsmith
Date: Tue Dec 29 17:42:34 2015
New Revision: 256602

URL: http://llvm.org/viewvc/llvm-project?rev=256602&view=rev
Log:
When a namespace alias redeclares a using declaration, point the diagnostic at
the using declaration not at the thing it's using.

Modified:
    cfe/trunk/lib/Sema/SemaDeclCXX.cpp
    cfe/trunk/test/SemaCXX/namespace-alias.cpp

Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=256602&r1=256601&r2=256602&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Tue Dec 29 17:42:34 2015
@@ -8688,9 +8688,9 @@ Decl *Sema::ActOnNamespaceAliasDef(Scope
 
   // Find the previous declaration and check that we can redeclare it.
   NamespaceAliasDecl *Prev = nullptr; 
-  if (NamedDecl *PrevDecl = PrevR.getAsSingle<NamedDecl>()) {
-    if (NamespaceAliasDecl *AD =
-            dyn_cast<NamespaceAliasDecl>(PrevR.getRepresentativeDecl())) {
+  if (PrevR.isSingleResult()) {
+    NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
+    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
       // We already have an alias with the same name that points to the same
       // namespace; check that it matches.
       if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
@@ -8703,7 +8703,7 @@ Decl *Sema::ActOnNamespaceAliasDef(Scope
         return nullptr;
       }
     } else if (isVisible(PrevDecl)) {
-      unsigned DiagID = isa<NamespaceDecl>(PrevDecl)
+      unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
                             ? diag::err_redefinition
                             : diag::err_redefinition_different_kind;
       Diag(AliasLoc, DiagID) << Alias;

Modified: cfe/trunk/test/SemaCXX/namespace-alias.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/namespace-alias.cpp?rev=256602&r1=256601&r2=256602&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/namespace-alias.cpp (original)
+++ cfe/trunk/test/SemaCXX/namespace-alias.cpp Tue Dec 29 17:42:34 2015
@@ -157,3 +157,14 @@ namespace MultipleUnambiguousLookupResul
   int x2 = X::x; // ok, unambiguous
   int y2 = Y::y; // ok, unambiguous
 }
+
+namespace RedeclOfNonNamespace {
+  int a; // expected-note {{previous}}
+  namespace X { int b; }
+  using X::b; // expected-note {{previous}}
+  namespace c {} // expected-note {{previous}}
+
+  namespace a = X; // expected-error {{different kind}}
+  namespace b = X; // expected-error {{different kind}}
+  namespace c = X; // expected-error-re {{redefinition of 'c'{{$}}}}
+}