From 9b6e2d209cc2931a9bb2ae51e744a8698b54db73 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Wed, 22 Oct 2008 00:38:21 +0000
Subject: [PATCH] Fix a thinko in the qualification-conversion check when the
 qualificaitons are disjoint, and add some overloading-based tests of
 qualification conversions

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57942 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/AST/Type.h       |  2 +-
 lib/Sema/SemaOverload.cpp      |  2 +-
 test/SemaCXX/overload-call.cpp | 29 +++++++++++++++++++++++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/include/clang/AST/Type.h b/include/clang/AST/Type.h
index b11f711255..07eae4427a 100644
--- a/include/clang/AST/Type.h
+++ b/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
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 2696c98523..6d01709c5b 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/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
diff --git a/test/SemaCXX/overload-call.cpp b/test/SemaCXX/overload-call.cpp
index 311e3d0d3e..165ee60c84 100644
--- a/test/SemaCXX/overload-call.cpp
+++ b/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); 
+}
-- 
2.40.0