Fix ownership of UnconditionalCheckedCastValue.

Author: atrick

include/swift/SIL/SILNodes.def

@@ -287,7 +287,7 @@ ABSTRACT_VALUE(SILInstruction, ValueBase)
     // accross the cast (which reads the type metadata). With Semantic SIL we
     // should be able to move this back to None - it should model the scoping
     // and forbid the compiler from moving the ultimate retain.
-    INST(UnconditionalCheckedCastValueInst, ConversionInst, unconditional_checked_cast_value, MayRead, DoesNotRelease)
+    INST(UnconditionalCheckedCastValueInst, ConversionInst, unconditional_checked_cast_value, MayRead, MayRelease)
     INST(UnconditionalCheckedCastInst, ConversionInst, unconditional_checked_cast, MayRead, DoesNotRelease)
     VALUE_RANGE(ConversionInst, UpcastInst, UnconditionalCheckedCastInst)
   INST(IsNonnullInst, SILInstruction, is_nonnull, None, DoesNotRelease)

lib/SIL/SILOwnershipVerifier.cpp

@@ -202,7 +202,6 @@ static bool isOwnershipForwardingValueKind(ValueKind K) {
   case ValueKind::RefToBridgeObjectInst:
   case ValueKind::BridgeObjectToRefInst:
   case ValueKind::UnconditionalCheckedCastInst:
-  case ValueKind::UnconditionalCheckedCastValueInst:
   case ValueKind::TupleExtractInst:
   case ValueKind::StructExtractInst:
   case ValueKind::UncheckedEnumDataInst:
@@ -529,6 +528,7 @@ CONSTANT_OWNERSHIP_INST(Trivial, false, DeallocValueBuffer)
             SHOULD_CHECK_FOR_DATAFLOW_VIOLATIONS};                             \
   }
 CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Owned, true, CheckedCastValueBranch)
+CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Owned, true, UnconditionalCheckedCastValue)
 CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Owned, true, InitExistentialValue)
 CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Owned, true, DeinitExistentialValue)
 #undef CONSTANT_OR_TRIVIAL_OWNERSHIP_INST
@@ -658,7 +658,6 @@ FORWARD_ANY_OWNERSHIP_INST(ConvertFunction)
 FORWARD_ANY_OWNERSHIP_INST(RefToBridgeObject)
 FORWARD_ANY_OWNERSHIP_INST(BridgeObjectToRef)
 FORWARD_ANY_OWNERSHIP_INST(UnconditionalCheckedCast)
-FORWARD_ANY_OWNERSHIP_INST(UnconditionalCheckedCastValue)
 FORWARD_ANY_OWNERSHIP_INST(MarkUninitialized)
 FORWARD_ANY_OWNERSHIP_INST(UncheckedEnumData)
 #undef FORWARD_ANY_OWNERSHIP_INST

lib/SIL/ValueOwnershipKindClassifier.cpp

@@ -45,7 +45,6 @@ CONSTANT_OWNERSHIP_INST(Owned, PartialApply)
 CONSTANT_OWNERSHIP_INST(Owned, StrongPin)
 CONSTANT_OWNERSHIP_INST(Owned, ThinToThickFunction)
 CONSTANT_OWNERSHIP_INST(Owned, InitExistentialValue)
-CONSTANT_OWNERSHIP_INST(Owned, UnconditionalCheckedCastValue)
 
 // One would think that these /should/ be unowned. In truth they are owned since
 // objc metatypes do not go through the retain/release fast path. In their
@@ -132,6 +131,7 @@ CONSTANT_OWNERSHIP_INST(Unowned, UnownedToRef)
   }
 CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Guaranteed, StructExtract)
 CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Guaranteed, TupleExtract)
+CONSTANT_OR_TRIVIAL_OWNERSHIP_INST(Owned, UnconditionalCheckedCastValue)
 #undef CONSTANT_OR_TRIVIAL_OWNERSHIP_INST
 
 // These are instructions that do not have any result, so we should never reach

test/SIL/ownership-verifier/opaque_use_verifier.sil

@@ -57,3 +57,25 @@ bb0(%0 : @guaranteed $T):
   destroy_value %1 : $T
   return %4 : $T
 }
+
+public protocol AnyObject : class {}
+
+sil @takeType : $@convention(thin) (@thick AnyObject.Type) -> () {
+bb0(%0 : @trivial $@thick AnyObject.Type):
+  %18 = tuple ()
+  return %18 : $()
+}
+
+// Test an unconditional cast from an owned value to a trivial value.
+sil @castToTrivial : $@convention(thin) (@owned AnyObject) -> () {
+bb0(%0 : @owned $AnyObject):
+  %6 = function_ref @takeType : $@convention(thin) (@thick AnyObject.Type) -> ()
+  %8 = begin_borrow %0 : $AnyObject
+  %9 = copy_value %8 : $AnyObject
+  %10 = unconditional_checked_cast_value take_always %9 : $AnyObject to $@thick AnyObject.Type
+  %11 = apply %6(%10) : $@convention(thin) (@thick AnyObject.Type) -> ()
+  end_borrow %8 from %0 : $AnyObject, $AnyObject
+  destroy_value %0 : $AnyObject
+  %18 = tuple ()
+  return %18 : $()
+}