Identity and non-identity standard conversion sequences can be

compared even when one is a reference binding and the other is not
(<rdar://problem/9173984>), but the definition of an identity sequence
does not involve lvalue-to-rvalue adjustments (PR9507). Fix both
inter-related issues.

llvm-svn: 132660

clang/include/clang/Sema/Overload.h

@@ -202,8 +202,7 @@ namespace clang {
     void setAsIdentityConversion();
     
     bool isIdentityConversion() const {
-      return First == ICK_Identity && Second == ICK_Identity && 
-             Third == ICK_Identity;
+      return Second == ICK_Identity && Third == ICK_Identity;
     }
     
     ImplicitConversionRank getRank() const;

clang/lib/Sema/SemaOverload.cpp

@@ -2523,12 +2523,10 @@ compareStandardConversionSubsets(ASTContext &Context,
 
   // the identity conversion sequence is considered to be a subsequence of
   // any non-identity conversion sequence
-  if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) {
   if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
     return ImplicitConversionSequence::Better;
   else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
     return ImplicitConversionSequence::Worse;
-  }
 
   if (SCS1.Second != SCS2.Second) {
     if (SCS1.Second == ICK_Identity)

clang/test/SemaCXX/overload-call.cpp

@@ -503,3 +503,25 @@ namespace rdar8499524 {
     g(W());
   }
 }
+
+namespace rdar9173984 {
+  template <typename T, unsigned long N> int &f(const T (&)[N]);
+  template <typename T> float &f(const T *);
+
+  void test() {
+    int arr[2] = {0, 0};
+    int *arrp = arr;
+    int &ir = f(arr);
+    float &fr = f(arrp);
+  }
+}
+
+namespace PR9507 {
+  void f(int * const&); // expected-note{{candidate function}}
+  void f(int const(&)[1]); // expected-note{{candidate function}}
+ 
+  int main() {
+    int n[1];
+    f(n); // expected-error{{call to 'f' is ambiguous}}
+  }
+}