Check that the namespace alias doesn't conflict with a previous declaration in this scope.
llvm-svn: 67921
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 349aafd..4c8437d 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -1675,12 +1675,24 @@
S->PushUsingDirective(UDir);
}
-Sema::DeclTy *Sema::ActOnNamespaceAliasDef(Scope *CurScope,
+Sema::DeclTy *Sema::ActOnNamespaceAliasDef(Scope *S,
SourceLocation AliasLoc,
IdentifierInfo *Alias,
const CXXScopeSpec &SS,
SourceLocation NamespaceLoc,
IdentifierInfo *NamespaceName) {
+
+ // Check if we have a previous declaration with the same name.
+ if (NamedDecl *PrevDecl = LookupName(S, Alias, LookupOrdinaryName)) {
+ // FIXME: If this is a namespace alias decl, and it points to the same
+ // namespace, we shouldn't warn.
+ unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
+ diag::err_redefinition_different_kind;
+ Diag(AliasLoc, DiagID) << Alias;
+ Diag(PrevDecl->getLocation(), diag::note_previous_definition);
+ return 0;
+ }
+
return 0;
}
diff --git a/clang/test/SemaCXX/namespace-alias.cpp b/clang/test/SemaCXX/namespace-alias.cpp
new file mode 100644
index 0000000..7458930
--- /dev/null
+++ b/clang/test/SemaCXX/namespace-alias.cpp
@@ -0,0 +1,11 @@
+// RUN: clang-cc -fsyntax-only -verify %s
+
+namespace N { };
+
+namespace A = N;
+
+int B; // expected-note {{previous definition is here}}
+namespace B = N; // expected-error {{redefinition of 'B' as different kind of symbol}}
+
+namespace C { } // expected-note {{previous definition is here}}
+namespace C = N; // expected-error {{redefinition of 'C'}}