From fbf8752597c978015af80ab4e948af1f80d63dd6 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 21 Oct 2011 15:47:52 +0000
Subject: [PATCH] When performing name lookup for the previous declaration of a
 field, be sure to consider all of the possible lookup results. We were
 assert()'ing (but behaving correctly) for unresolved values. Fixes PR11134 /
 <rdar://problem/10290422>.

llvm-svn: 142652
---
 clang/lib/Sema/SemaDecl.cpp                   | 25 +++++++++++++------
 .../test/SemaTemplate/class-template-decl.cpp |  1 +
 .../test/SemaTemplate/member-access-ambig.cpp | 10 ++++++++
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index c7873fa06820..f554cffba9ba 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8421,16 +8421,25 @@ FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record,
       << 2;
   
   // Check to see if this name was declared as a member previously
+  NamedDecl *PrevDecl = 0;
   LookupResult Previous(*this, II, Loc, LookupMemberName, ForRedeclaration);
   LookupName(Previous, S);
-  assert((Previous.empty() || Previous.isOverloadedResult() || 
-          Previous.isSingleResult()) 
-    && "Lookup of member name should be either overloaded, single or null");
-
-  // If the name is overloaded then get any declaration else get the single 
-  // result
-  NamedDecl *PrevDecl = Previous.isOverloadedResult() ?
-    Previous.getRepresentativeDecl() : Previous.getAsSingle<NamedDecl>();
+  switch (Previous.getResultKind()) {
+    case LookupResult::Found:
+    case LookupResult::FoundUnresolvedValue:
+      PrevDecl = Previous.getAsSingle<NamedDecl>();
+      break;
+      
+    case LookupResult::FoundOverloaded:
+      PrevDecl = Previous.getRepresentativeDecl();
+      break;
+      
+    case LookupResult::NotFound:
+    case LookupResult::NotFoundInCurrentInstantiation:
+    case LookupResult::Ambiguous:
+      break;
+  }
+  Previous.suppressDiagnostics();
 
   if (PrevDecl && PrevDecl->isTemplateParameter()) {
     // Maybe we will complain about the shadowed template parameter.
diff --git a/clang/test/SemaTemplate/class-template-decl.cpp b/clang/test/SemaTemplate/class-template-decl.cpp
index 2e84e93ead97..38b1778abf44 100644
--- a/clang/test/SemaTemplate/class-template-decl.cpp
+++ b/clang/test/SemaTemplate/class-template-decl.cpp
@@ -74,3 +74,4 @@ namespace PR8001 {
     Foo<int>::Bar<int> y(x);
   }
 }
+
diff --git a/clang/test/SemaTemplate/member-access-ambig.cpp b/clang/test/SemaTemplate/member-access-ambig.cpp
index bf190435ecd5..f8a01d5fff2a 100644
--- a/clang/test/SemaTemplate/member-access-ambig.cpp
+++ b/clang/test/SemaTemplate/member-access-ambig.cpp
@@ -33,3 +33,13 @@ void X::g()
   // expected-error{{expected '(' for function-style cast}} \
   // expected-error{{expected expression}}
 }
+
+namespace PR11134 {
+  template<typename Derived> class A;
+  template<typename Derived> class B : A<Derived> {
+    typedef A<Derived> Base;
+    using Base::member;
+    int member;
+  };
+}
+