This is part of a series of commits to remove reference forwarding

for some of the ARC entry points. rdar://22724641. After this commit,
swift_unknownRetain will forward no reference.

Swift SVN r32083

include/swift/Runtime/HeapObject.h

@@ -437,10 +437,10 @@ extern "C" void *swift_bridgeObjectRetain_n(void *value, int n);
 
 /// Increment the strong retain count of an object which might not be a native
 /// Swift object.
-extern "C" void *swift_unknownRetain(void *value);
+extern "C" void swift_unknownRetain(void *value);
 /// Increment the strong retain count of an object which might not be a native
 /// Swift object by n.
-extern "C" void *swift_unknownRetain_n(void *value, int n);
+extern "C" void swift_unknownRetain_n(void *value, int n);
 
 #else
 

lib/IRGen/RuntimeFunctions.def

@@ -143,9 +143,9 @@ FUNCTION(FixLifetime, swift_fixLifetime, RuntimeCC,
          ARGS(RefCountedPtrTy),
          ATTRS(NoUnwind))
 
-// void *swift_unknownRetain(void *ptr);
+// void swift_unknownRetain(void *ptr);
 FUNCTION(UnknownRetain, swift_unknownRetain, RuntimeCC,
-         RETURNS(RefCountedPtrTy),
+         RETURNS(VoidTy),
          ARGS(RefCountedPtrTy),
          ATTRS(NoUnwind))
 

stdlib/public/runtime/MetadataImpl.h

@@ -442,7 +442,8 @@ struct ObjCWeakRetainableBox :
 struct UnknownRetainableBox : RetainableBoxBase<UnknownRetainableBox, void*> {
   static void *retain(void *obj) {
 #if SWIFT_OBJC_INTEROP
-    return swift_unknownRetain(obj);
+    swift_unknownRetain(obj);
+    return obj;
 #else
     swift_retain(static_cast<HeapObject *>(obj));
     return static_cast<HeapObject *>(obj);

stdlib/public/runtime/Reflection.mm

@@ -291,7 +291,8 @@ AnyReturn swift_MagicMirrorData_objcValue(HeapObject *owner,
   void *object = *reinterpret_cast<void * const *>(value);
   auto isa = _swift_getClass(object);
   result.Type = swift_getObjCClassMetadata(isa);
-  *reinterpret_cast<void **>(&result.Buffer) = swift_unknownRetain(object);
+  swift_unknownRetain(object);
+  *reinterpret_cast<void **>(&result.Buffer) = object;
   return AnyReturn(result);
 }
 #endif

stdlib/public/runtime/SwiftObject.mm

@@ -566,16 +566,14 @@ static bool usesNativeSwiftReferenceCounting_unowned(const void *object) {
   return usesNativeSwiftReferenceCounting_allocated(object);
 }
 
-void *swift::swift_unknownRetain_n(void *object, int n) {
-  void *objc_ret = nullptr;
-  if (isObjCTaggedPointerOrNull(object)) return object;
+void swift::swift_unknownRetain_n(void *object, int n) {
+  if (isObjCTaggedPointerOrNull(object)) return;
   if (usesNativeSwiftReferenceCounting_allocated(object)) {
     swift_retain_n(static_cast<HeapObject *>(object), n);
-    return static_cast<HeapObject *>(object);
+    return;
   }
   for (int i = 0; i < n; ++i)
-    objc_ret = objc_retain(static_cast<id>(object));
-  return objc_ret;
+    objc_retain(static_cast<id>(object));
 }
 
 void swift::swift_unknownRelease_n(void *object, int n) {
@@ -586,13 +584,13 @@ static bool usesNativeSwiftReferenceCounting_unowned(const void *object) {
     objc_release(static_cast<id>(object));
 }
 
-void *swift::swift_unknownRetain(void *object) {
-  if (isObjCTaggedPointerOrNull(object)) return object;
+void swift::swift_unknownRetain(void *object) {
+  if (isObjCTaggedPointerOrNull(object)) return;
   if (usesNativeSwiftReferenceCounting_allocated(object)) {
     swift_retain(static_cast<HeapObject *>(object));
-    return static_cast<HeapObject *>(object);
+    return;
   }
-  return objc_retain(static_cast<id>(object));
+  objc_retain(static_cast<id>(object));
 }
 
 void swift::swift_unknownRelease(void *object) {

test/IRGen/class_bounded_generics.swift

@@ -93,7 +93,7 @@ func class_bounded_archetype_method<T : ClassBoundBinary>(x: T, y: T) {
   x.classBoundBinaryMethod(y)
   // CHECK: [[WITNESS_ENTRY:%.*]] = getelementptr inbounds i8*, i8** %T.ClassBoundBinary, i32 1
   // CHECK: [[WITNESS:%.*]] = load i8*, i8** [[WITNESS_ENTRY]], align 8
-  // CHECK: call void bitcast (%swift.refcounted* (%swift.refcounted*)* @swift_unknownRetain to void (%objc_object*)*)(%objc_object* [[Y:%.*]])
+  // CHECK: call void bitcast (void (%swift.refcounted*)* @swift_unknownRetain to void (%objc_object*)*)(%objc_object* [[Y:%.*]])
   // CHECK: [[WITNESS_FUNC:%.*]] = bitcast i8* [[WITNESS]] to void (%objc_object*, %objc_object*, %swift.type*)
   // CHECK: call void [[WITNESS_FUNC]](%objc_object* [[Y]], %objc_object* %0, %swift.type* {{.*}})
 }

test/LLVMPasses/basic.ll

@@ -8,7 +8,7 @@ target triple = "x86_64-apple-macosx10.9"
 %objc_object = type opaque
 %swift.bridge = type opaque
 
-declare %swift.refcounted* @swift_unknownRetain(%swift.refcounted*)
+declare void @swift_unknownRetain(%swift.refcounted*)
 declare void @swift_unknownRelease(%swift.refcounted*)
 declare %objc_object* @objc_retain(%objc_object*)
 declare void @objc_release(%objc_object*)
@@ -32,13 +32,13 @@ define void @trivial_retain_release(%swift.refcounted* %P, %objc_object* %O, %sw
 entry:
   tail call void @swift_retain(%swift.refcounted* %P)
   tail call void @swift_release(%swift.refcounted* %P) nounwind
-  %0 = tail call %swift.refcounted* @swift_unknownRetain(%swift.refcounted* %P)
+  tail call void @swift_unknownRetain(%swift.refcounted* %P)
   tail call void @swift_unknownRelease(%swift.refcounted* %P)
   tail call %objc_object* @objc_retain(%objc_object* %O)
   tail call void @objc_release(%objc_object* %O)
   %v = tail call %swift.bridge* @swift_bridgeObjectRetain(%swift.bridge* %B)
   tail call void @swift_bridgeObjectRelease(%swift.bridge* %v)
-  call void @user(%swift.refcounted* %0) nounwind
+  call void @user(%swift.refcounted* %P) nounwind
   ret void
 }
 
@@ -79,7 +79,7 @@ entry:
 define void @swiftunknown_retain_release_null() {
 entry:
   tail call void @swift_unknownRelease(%swift.refcounted* null)
-  tail call %swift.refcounted* @swift_unknownRetain(%swift.refcounted* null) nounwind
+  tail call void @swift_unknownRetain(%swift.refcounted* null) nounwind
   ret void
 }
 
@@ -115,7 +115,7 @@ define void @swift_fixLifetimeTest(%swift.refcounted* %A) {
 ; CHECK: ret
 define void @move_retain_across_unknown_retain(%swift.refcounted* %A, %swift.refcounted* %B) {
   tail call void @swift_retain(%swift.refcounted* %A)
-  tail call %swift.refcounted* @swift_unknownRetain(%swift.refcounted* %B)
+  tail call void @swift_unknownRetain(%swift.refcounted* %B)
   tail call void @swift_release(%swift.refcounted* %A) nounwind
   ret void
 }

unittests/runtime/Refcounting.mm

@@ -33,10 +33,8 @@ - (void) dealloc {
 
 TEST(RefcountingTest, objc_unknown_retain_release_n) {
   auto object = make_objc_object();
-  auto retainResult = swift_unknownRetain_n(object, 32);
-  EXPECT_EQ(object, retainResult);
-  retainResult = swift_unknownRetain(object);
-  EXPECT_EQ(object, retainResult);
+  swift_unknownRetain_n(object, 32);
+  swift_unknownRetain(object);
   swift_unknownRelease_n(object, 31);
   swift_unknownRelease(object);
   swift_unknownRelease_n(object, 1);