[OpenCL] Fix overloading ranking rules for addrspace conversions.

Extend ranking to work with address spaces correctly when
resolving overloads.

Differential Revision: https://reviews.llvm.org/D56735

llvm-svn: 351546

Author: Anastasia Stulova

clang/lib/Sema/SemaOverload.cpp

@@ -4019,9 +4019,12 @@ CompareQualificationConversions(Sema &S,
     // to unwrap. This essentially mimics what
     // IsQualificationConversion does, but here we're checking for a
     // strict subset of qualifiers.
-    if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
+    if (T1.getQualifiers().withoutObjCLifetime() ==
+        T2.getQualifiers().withoutObjCLifetime())
       // The qualifiers are the same, so this doesn't tell us anything
       // about how the sequences rank.
+      // ObjC ownership quals are omitted above as they interfere with
+      // the ARC overload rule.
       ;
     else if (T2.isMoreQualifiedThan(T1)) {
       // T1 has fewer qualifiers, so it could be the better sequence.

clang/test/SemaOpenCLCXX/address_space_overloading.cl

@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -cl-std=c++
+
+// expected-no-diagnostics
+
+struct RetGlob {
+  int dummy;
+};
+
+struct RetGen {
+  char dummy;
+};
+
+RetGlob foo(const __global int *);
+RetGen foo(const __generic int *);
+
+void kernel k() {
+  __global int *ArgGlob;
+  __generic int *ArgGen;
+  __local int *ArgLoc;
+  RetGlob TestGlob = foo(ArgGlob);
+  RetGen TestGen = foo(ArgGen);
+  TestGen = foo(ArgLoc);
+}