From: Eli Friedman <eli.friedman@gmail.com>
Date: Tue, 20 Aug 2013 00:39:40 +0000 (+0000)
Subject: Fix name lookup with dependent using decls.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=13b572c9e84729b4bd5f00d0f1452a4b93211cde;p=clang

Fix name lookup with dependent using decls.

We previously mishandled UnresolvedUsingValueDecls in
NamedDecl::declarationReplaces, which caused us to forget decls
when there are multiple dependent using decls for the same name.

Fixes PR16936.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188737 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 9562879de6..1c2ead0ee5 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1353,6 +1353,15 @@ bool NamedDecl::declarationReplaces(NamedDecl *OldD) const {
                                         cast<UsingDecl>(OldD)->getQualifier());
   }
 
+  if (isa<UnresolvedUsingValueDecl>(this) &&
+      isa<UnresolvedUsingValueDecl>(OldD)) {
+    ASTContext &Context = getASTContext();
+    return Context.getCanonicalNestedNameSpecifier(
+                      cast<UnresolvedUsingValueDecl>(this)->getQualifier()) ==
+           Context.getCanonicalNestedNameSpecifier(
+                        cast<UnresolvedUsingValueDecl>(OldD)->getQualifier());
+  }
+
   // A typedef of an Objective-C class type can replace an Objective-C class
   // declaration or definition, and vice versa.
   if ((isa<TypedefNameDecl>(this) && isa<ObjCInterfaceDecl>(OldD)) ||
diff --git a/test/SemaTemplate/instantiate-using-decl.cpp b/test/SemaTemplate/instantiate-using-decl.cpp
index 1bfcb7a865..a6a4ea0e0f 100644
--- a/test/SemaTemplate/instantiate-using-decl.cpp
+++ b/test/SemaTemplate/instantiate-using-decl.cpp
@@ -80,3 +80,27 @@ namespace test3 {
     b.f1();
   }
 }
+
+namespace PR16936 {
+  // Make sure both using decls are properly considered for
+  // overload resolution.
+  template<class> struct A {
+    void access(int);
+  };
+  template<class> struct B {
+    void access();
+  };
+  template<class CELL> struct X : public A<CELL>, public B<CELL> {
+    using A<CELL>::access;
+    using B<CELL>::access;
+
+    void f() {
+      access(0);
+    }
+  };
+
+  void f() {
+    X<int> x;
+    x.f();
+  }
+}