mirror of
https://github.com/apple/swift.git
synced 2026-10-16 16:50:49 +02:00
Kavon Farvardin
3b5455711c
Protocols that are resilient parents (previously `@reparentable`) can become new parents of existing resilient protocols through a `@reparented` extension. If that extension is less available than the current deployment target, folding that dynamic cast would be a mis-optimization. For now this patch pessimizes the folding of all casts to such protocols like Iterable. rdar://175354629
38 lines
1.4 KiB
Swift
38 lines
1.4 KiB
Swift
// RUN: %target-swift-frontend -O -Xllvm -sil-print-types -Xllvm -sil-disable-pass=function-signature-opts -emit-sil -enable-experimental-feature Reparenting %s | %FileCheck %s
|
|
|
|
// REQUIRES: swift_feature_Reparenting
|
|
|
|
// A cast to a resilient-parent (@reparentable) protocol must never be folded
|
|
// statically: a @reparented extension can introduce the inheritance edge at an
|
|
// availability newer than the deployment target, so the conformance is not
|
|
// guaranteed to exist at runtime. This holds regardless of how the source
|
|
// conforms or what the deployment target is.
|
|
|
|
@reparentable
|
|
public protocol RP {}
|
|
|
|
public protocol Child: RP {}
|
|
extension Child: @reparented RP {}
|
|
|
|
public final class C: Child {}
|
|
|
|
// The cast to RP is kept: it is not statically foldable.
|
|
// CHECK-LABEL: sil [noinline] @$s25cast_folding_reparentable0A4ToRPySbAA1CCF :
|
|
// CHECK: checked_cast_addr_br {{.*}} C in {{.*}} to any RP
|
|
// CHECK: } // end sil function '$s25cast_folding_reparentable0A4ToRPySbAA1CCF'
|
|
@inline(never)
|
|
public func castToRP(_ x: C) -> Bool {
|
|
return x is RP
|
|
}
|
|
|
|
// Casting to an ordinary protocol still folds, even one that inherits from a
|
|
// @reparentable protocol: only casts whose target is itself @reparentable are
|
|
// pessimized.
|
|
// CHECK-LABEL: sil [noinline] @$s25cast_folding_reparentable0A7ToChildySbAA1CCF :
|
|
// CHECK-NOT: checked_cast
|
|
// CHECK: integer_literal $Builtin.Int1, -1
|
|
@inline(never)
|
|
public func castToChild(_ x: C) -> Bool {
|
|
return x is Child
|
|
}
|