Fix a thinko in the qualification-conversion check when the qualificaitons are disjoint, and add some overloading-based tests of qualification conversions

llvm-svn: 57942

clang/include/clang/AST/Type.h

@@ -178,7 +178,7 @@ public:
   bool isAtLeastAsQualifiedAs(QualType Other) const {
     unsigned MyQuals = this->getCVRQualifiers();
     unsigned OtherQuals = Other.getCVRQualifiers();
-    return MyQuals | OtherQuals == MyQuals;
+    return (MyQuals | OtherQuals) == MyQuals;
   }
 
   /// operator==/!= - Indicate whether the specified types and qualifiers are

clang/lib/Sema/SemaOverload.cpp

@@ -685,7 +685,7 @@ Sema::IsQualificationConversion(QualType FromType, QualType ToType)
 
     //   -- for every j > 0, if const is in cv 1,j then const is in cv
     //      2,j, and similarly for volatile.
-    if (FromType.isMoreQualifiedThan(ToType))
+    if (!ToType.isAtLeastAsQualifiedAs(FromType))
       return false;
 
     //   -- if the cv 1,j and cv 2,j are different, then const is in

clang/test/SemaCXX/overload-call.cpp

@@ -135,3 +135,32 @@ void test_multiparm(long lv, short sv, int iv) {
   double* dp2 = multiparm(iv, sv, sv);
   multiparm(sv, sv, lv); // expected-error {{ call to 'multiparm' is ambiguous; candidates are: }}
 }
+
+// Test overloading based on qualification vs. no qualification
+// conversion.
+int* quals1(int const * p);
+char* quals1(int * p);
+
+int* quals2(int const * const * pp);
+char* quals2(int * * pp);
+
+int* quals3(int const * * const * ppp);
+char* quals3(int *** ppp);
+
+void test_quals(int * p, int * * pp, int * * * ppp) {
+  char* q1 = quals1(p);
+  char* q2 = quals2(pp);
+  char* q3 = quals3(ppp);
+}
+
+// Test overloading based on qualification ranking (C++ 13.3.2)p3.
+int* quals_rank1(int const * p);
+float* quals_rank1(int const volatile *p);
+
+int* quals_rank2(int const * const * pp);
+float* quals_rank2(int * const * pp);
+
+void test_quals_ranking(int * p, int volatile *pq, int * * pp, int * * * ppp) {
+  //  int* q1 = quals_rank1(p);
+  float* q2 = quals_rank1(pq); 
+}