Implement the restriction that a function with a ref-qualifier cannot

overload a function without a ref-qualifier (C++0x
[over.load]p2). This, apparently, completes the implementation of
rvalue references for *this.

llvm-svn: 124321

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2481,6 +2481,11 @@ def err_invalid_ref_qualifier_typedef_function_type_use : Error<
   "%select{static member|nonmember}0 function cannot have a ref-qualifier "
   "'%select{&&|&}1'">;
 
+def err_ref_qualifier_overload : Error<
+  "cannot overload a member function %select{without a ref-qualifier|with "
+  "ref-qualifier '&'|with ref-qualifier '&&'}0 with a member function %select{"
+  "without a ref-qualifier|with ref-qualifier '&'|with ref-qualifier '&&'}1">;
+
 def err_invalid_non_static_member_use : Error<
   "invalid use of nonstatic data member %0">;
 def err_invalid_incomplete_type_use : Error<

clang/lib/Sema/SemaOverload.cpp

@@ -694,8 +694,24 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
   if (OldMethod && NewMethod &&
       !OldMethod->isStatic() && !NewMethod->isStatic() &&
       (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() ||
-       OldMethod->getRefQualifier() != NewMethod->getRefQualifier()))
+       OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) {
+    if (!UseUsingDeclRules &&
+        OldMethod->getRefQualifier() != NewMethod->getRefQualifier() &&
+        (OldMethod->getRefQualifier() == RQ_None ||
+         NewMethod->getRefQualifier() == RQ_None)) {
+      // C++0x [over.load]p2:
+      //   - Member function declarations with the same name and the same 
+      //     parameter-type-list as well as member function template 
+      //     declarations with the same name, the same parameter-type-list, and 
+      //     the same template parameter lists cannot be overloaded if any of 
+      //     them, but not all, have a ref-qualifier (8.3.5).
+      Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
+        << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
+      Diag(OldMethod->getLocation(), diag::note_previous_declaration);
+    }
+        
     return true;
+  }
   
   // The signatures match; this is not an overload.
   return false;

clang/test/CXX/over/over.load/p2-0x.cpp

@@ -10,12 +10,15 @@ class Y {
   void h() &; 
   void h() const &; 
   void h() &&; 
-  void i() &; 
-  void i() const; // FIXME: expected an error here!
+  void i() &; // expected-note{{previous declaration}}
+  void i() const; // expected-error{{cannot overload a member function without a ref-qualifier with a member function with ref-qualifier '&'}}
 
   template<typename T> void f(T*) &;
   template<typename T> void f(T*) &&;
 
-  template<typename T> void g(T*) &;
-  template<typename T> void g(T*); // FIXME: expected an error here
+  template<typename T> void g(T*) &; // expected-note{{previous declaration}}
+  template<typename T> void g(T*); // expected-error{{cannot overload a member function without a ref-qualifier with a member function with ref-qualifier '&'}}
+
+  void k(); // expected-note{{previous declaration}}
+  void k() &&; // expected-error{{cannot overload a member function with ref-qualifier '&&' with a member function without a ref-qualifier}}
 };