Fix a small bug in the way we handle builtin candidates for

relational operators of enumeration type.  From the gcc testsuite.

llvm-svn: 164171

clang/lib/Sema/SemaOverload.cpp

@@ -6790,17 +6790,16 @@ public:
   //        bool       operator==(T, T);
   //        bool       operator!=(T, T);
   void addRelationalPointerOrEnumeralOverloads() {
-    // C++ [over.built]p1:
-    //   If there is a user-written candidate with the same name and parameter
-    //   types as a built-in candidate operator function, the built-in operator
-    //   function is hidden and is not included in the set of candidate
-    //   functions.
+    // C++ [over.match.oper]p3:
+    //   [...]the built-in candidates include all of the candidate operator
+    //   functions defined in 13.6 that, compared to the given operator, [...]
+    //   do not have the same parameter-type-list as any non-template non-member
+    //   candidate.
     //
-    // The text is actually in a note, but if we don't implement it then we end
-    // up with ambiguities when the user provides an overloaded operator for
-    // an enumeration type. Note that only enumeration types have this problem,
-    // so we track which enumeration types we've seen operators for. Also, the
-    // only other overloaded operator with enumeration argumenst, operator=,
+    // Note that in practice, this only affects enumeration types because there
+    // aren't any built-in candidates of record type, and a user-defined operator
+    // must have an operand of record or enumeration type. Also, the only other
+    // overloaded operator with enumeration arguments, operator=,
     // cannot be overloaded for enumeration types, so this is the only place
     // where we must suppress candidates like this.
     llvm::DenseSet<std::pair<CanQualType, CanQualType> >
@@ -6815,6 +6814,9 @@ public:
           if (!C->Viable || !C->Function || C->Function->getNumParams() != 2)
             continue;
 
+          if (C->Function->isFunctionTemplateSpecialization())
+            continue;
+
           QualType FirstParamType =
             C->Function->getParamDecl(0)->getType().getUnqualifiedType();
           QualType SecondParamType =

clang/test/CXX/over/over.built/p1.cpp

@@ -1,16 +0,0 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
-
-enum E1 { one };
-enum E2 { two };
-
-bool operator >= (E1, E1) {
-  return false;
-}
-
-bool operator >= (E1, const E2) {
-  return false;
-}
-
-bool test(E1 a, E1 b, E2 c) {
-  return a >= b || a >= c;
-}

clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p3.cpp

@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+
+// This is specifically testing the bullet:
+// "do not have the same parameter-type-list as any non-template
+// non-member candidate."
+// The rest is sort of hard to test separately.
+
+enum E1 { one };
+enum E2 { two };
+
+struct A;
+
+A operator >= (E1, E1);
+A operator >= (E1, const E2);
+
+E1 a;
+E2 b;
+
+extern A test1;
+extern decltype(a >= a) test1;
+extern decltype(a >= b) test1;
+
+template <typename T> A operator <= (E1, T);
+extern bool test2;
+extern decltype(a <= a) test2;
+
+extern A test3;
+extern decltype(a <= b) test3;