Implement redeclaration checking and hiding semantics for using declarations. There

are a couple of O(n^2) operations in this, some analogous to the usual O(n^2)
redeclaration problem and some not.  In particular, retroactively removing
shadow declarations when they're hidden by later decls is pretty unfortunate.
I'm not yet convinced it's worse than the alternative, though.

llvm-svn: 91045

1 files changed, 10 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index 48d7320d2e9..66c846b078f 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -222,6 +222,11 @@ getIdentifierNamespacesFromLookupNameKind(Sema::LookupNameKind NameKind,
     IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member;
     break;
 
+  case Sema::LookupUsingDeclName:
+    IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag
+         | Decl::IDNS_Member | Decl::IDNS_Using;
+    break;
+
   case Sema::LookupObjCProtocolName:
     IDNS = Decl::IDNS_ObjCProtocol;
     break;
@@ -245,7 +250,7 @@ void LookupResult::deletePaths(CXXBasePaths *Paths) {
 /// Resolves the result kind of this lookup.
 void LookupResult::resolveKind() {
   unsigned N = Decls.size();
-
+ 
   // Fast case: no possible ambiguity.
   if (N == 0) {
     assert(ResultKind == NotFound);
@@ -613,6 +618,7 @@ bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
     case Sema::LookupOperatorName:
     case Sema::LookupNestedNameSpecifierName:
     case Sema::LookupNamespaceName:
+    case Sema::LookupUsingDeclName:
       assert(false && "C does not perform these kinds of name lookup");
       break;
 
@@ -928,6 +934,9 @@ bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx) {
     case LookupTagName:
       BaseCallback = &CXXRecordDecl::FindTagMember;
       break;
+
+    case LookupUsingDeclName:
+      // This lookup is for redeclarations only.
       
     case LookupOperatorName:
     case LookupNamespaceName: