From 7a343142901f7f6bd1965051a24ae6a12c6f2148 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Sun, 1 Nov 2009 17:08:18 +0000
Subject: [PATCH] Within a template, qualified name lookup can refer to a
 non-dependent type that is not known to be a base class at template
 definition time due to some dependent base class. Treat qualified name lookup
 that refers to a non-static data member or function as implicit class member
 access when the "this" type would be dependent.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@85718 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaExprCXX.cpp                 |  6 ++++++
 test/SemaTemplate/instantiate-method.cpp | 17 +++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 32eeddb0fe..fad1f3e263 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -2395,6 +2395,12 @@ bool Sema::isImplicitMemberReference(const CXXScopeSpec *SS, NamedDecl *D,
   // Determine whether the declaration(s) we found are actually in a base 
   // class. If not, this isn't an implicit member reference.
   ThisType = MD->getThisType(Context);
+  
+  // If the type of "this" is dependent, we can't tell if the member is in a 
+  // base class or not, so treat this as a dependent implicit member reference.
+  if (ThisType->isDependentType())
+    return true;
+  
   QualType CtxType = Context.getTypeDeclType(cast<CXXRecordDecl>(Ctx));
   QualType ClassType
     = Context.getTypeDeclType(cast<CXXRecordDecl>(MD->getParent()));
diff --git a/test/SemaTemplate/instantiate-method.cpp b/test/SemaTemplate/instantiate-method.cpp
index f7c09ef879..df1e1d964e 100644
--- a/test/SemaTemplate/instantiate-method.cpp
+++ b/test/SemaTemplate/instantiate-method.cpp
@@ -81,3 +81,20 @@ int *a(A0<int> &x0, A1<int> &x1) {
   int *y0 = x0;
   int *y1 = x1; // expected-error{{initializing}}
 }
+
+struct X0Base {
+  int &f();
+};
+
+template<typename T>
+struct X0 : X0Base {
+};
+
+template<typename U>
+struct X1 : X0<U> {
+  int &f2() { return X0Base::f(); }
+};
+
+void test_X1(X1<int> x1i) {
+  int &ir = x1i.f2();
+}