mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
1202 lines
39 KiB
Swift
1202 lines
39 KiB
Swift
//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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import SwiftShims
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@_transparent
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internal func _abstract(
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methodName: StaticString = #function,
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file: StaticString = #file, line: UInt = #line
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) -> Never {
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#if INTERNAL_CHECKS_ENABLED
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_fatalErrorMessage("abstract method", methodName, file: file, line: line,
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flags: _fatalErrorFlags())
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#else
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_conditionallyUnreachable()
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#endif
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}
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// MARK: Type-erased abstract base classes
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public class AnyKeyPath: Hashable, _AppendKeyPath {
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@_inlineable
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public static var rootType: Any.Type {
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return _rootAndValueType.root
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}
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@_inlineable
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public static var valueType: Any.Type {
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return _rootAndValueType.value
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}
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final public var hashValue: Int {
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var hash = 0
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withBuffer {
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var buffer = $0
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while true {
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let (component, type) = buffer.next()
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hash ^= _mixInt(component.value.hashValue)
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if let type = type {
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hash ^= _mixInt(unsafeBitCast(type, to: Int.self))
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} else {
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break
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}
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}
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}
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return hash
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}
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public static func ==(a: AnyKeyPath, b: AnyKeyPath) -> Bool {
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// Fast-path identical objects
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if a === b {
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return true
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}
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// Short-circuit differently-typed key paths
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if type(of: a) != type(of: b) {
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return false
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}
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return a.withBuffer {
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var aBuffer = $0
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return b.withBuffer {
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var bBuffer = $0
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// Two equivalent key paths should have the same reference prefix
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if aBuffer.hasReferencePrefix != bBuffer.hasReferencePrefix {
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return false
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}
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while true {
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let (aComponent, aType) = aBuffer.next()
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let (bComponent, bType) = bBuffer.next()
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if aComponent.header.endOfReferencePrefix
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!= bComponent.header.endOfReferencePrefix
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|| aComponent.value != bComponent.value
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|| aType != bType {
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return false
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}
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if aType == nil {
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return true
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}
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}
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}
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}
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}
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// SPI for the Foundation overlay to allow interop with KVC keypath-based
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// APIs.
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public var _kvcKeyPathString: String? {
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// TODO
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return nil
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}
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// MARK: Implementation details
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// Prevent normal initialization. We use tail allocation via
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// allocWithTailElems().
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internal init() {
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_sanityCheckFailure("use _create(...)")
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}
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// internal-with-availability
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public class var _rootAndValueType: (root: Any.Type, value: Any.Type) {
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_abstract()
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}
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public // @testable
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static func _create(
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capacityInBytes bytes: Int,
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initializedBy body: (UnsafeMutableRawBufferPointer) -> Void
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) -> Self {
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_sanityCheck(bytes > 0 && bytes % 4 == 0,
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"capacity must be multiple of 4 bytes")
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let result = Builtin.allocWithTailElems_1(self, (bytes/4)._builtinWordValue,
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Int32.self)
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let base = UnsafeMutableRawPointer(Builtin.projectTailElems(result,
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Int32.self))
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body(UnsafeMutableRawBufferPointer(start: base, count: bytes))
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return result
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}
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func withBuffer<T>(_ f: (KeyPathBuffer) throws -> T) rethrows -> T {
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defer { _fixLifetime(self) }
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let base = UnsafeRawPointer(Builtin.projectTailElems(self, Int32.self))
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return try f(KeyPathBuffer(base: base))
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}
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}
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public class PartialKeyPath<Root>: AnyKeyPath { }
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// MARK: Concrete implementations
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internal enum KeyPathKind { case readOnly, value, reference }
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public class KeyPath<Root, Value>: PartialKeyPath<Root> {
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public typealias _Root = Root
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public typealias _Value = Value
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public final override class var _rootAndValueType: (
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root: Any.Type,
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value: Any.Type
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) {
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return (Root.self, Value.self)
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}
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// MARK: Implementation
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typealias Kind = KeyPathKind
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class var kind: Kind { return .readOnly }
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static func appendedType<AppendedValue>(
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with t: KeyPath<Value, AppendedValue>.Type
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) -> KeyPath<Root, AppendedValue>.Type {
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let resultKind: Kind
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switch (self.kind, t.kind) {
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case (_, .reference):
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resultKind = .reference
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case (let x, .value):
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resultKind = x
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default:
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resultKind = .readOnly
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}
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switch resultKind {
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case .readOnly:
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return KeyPath<Root, AppendedValue>.self
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case .value:
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return WritableKeyPath.self
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case .reference:
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return ReferenceWritableKeyPath.self
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}
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}
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final func projectReadOnly(from root: Root) -> Value {
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// TODO: For perf, we could use a local growable buffer instead of Any
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var curBase: Any = root
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return withBuffer {
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var buffer = $0
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while true {
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let (rawComponent, optNextType) = buffer.next()
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let valueType = optNextType ?? Value.self
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let isLast = optNextType == nil
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func project<CurValue>(_ base: CurValue) -> Value? {
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func project2<NewValue>(_: NewValue.Type) -> Value? {
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let newBase: NewValue = rawComponent.projectReadOnly(base)
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if isLast {
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_sanityCheck(NewValue.self == Value.self,
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"key path does not terminate in correct type")
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return unsafeBitCast(newBase, to: Value.self)
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} else {
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curBase = newBase
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return nil
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}
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}
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return _openExistential(valueType, do: project2)
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}
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if let result = _openExistential(curBase, do: project) {
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return result
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}
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}
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}
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}
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deinit {
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withBuffer { $0.destroy() }
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}
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}
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public class WritableKeyPath<Root, Value>: KeyPath<Root, Value> {
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// MARK: Implementation detail
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override class var kind: Kind { return .value }
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// `base` is assumed to be undergoing a formal access for the duration of the
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// call, so must not be mutated by an alias
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func projectMutableAddress(from base: UnsafePointer<Root>)
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-> (pointer: UnsafeMutablePointer<Value>, owner: Builtin.NativeObject) {
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var p = UnsafeRawPointer(base)
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var type: Any.Type = Root.self
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var keepAlive: [AnyObject] = []
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return withBuffer {
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var buffer = $0
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_sanityCheck(!buffer.hasReferencePrefix,
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"WritableKeyPath should not have a reference prefix")
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while true {
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let (rawComponent, optNextType) = buffer.next()
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let nextType = optNextType ?? Value.self
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func project<CurValue>(_: CurValue.Type) {
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func project2<NewValue>(_: NewValue.Type) {
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p = rawComponent.projectMutableAddress(p,
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from: CurValue.self,
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to: NewValue.self,
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isRoot: p == UnsafeRawPointer(base),
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keepAlive: &keepAlive)
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}
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_openExistential(nextType, do: project2)
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}
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_openExistential(type, do: project)
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if optNextType == nil { break }
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type = nextType
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}
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// TODO: With coroutines, it would be better to yield here, so that
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// we don't need the hack of the keepAlive array to manage closing
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// accesses.
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let typedPointer = p.assumingMemoryBound(to: Value.self)
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return (pointer: UnsafeMutablePointer(mutating: typedPointer),
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owner: keepAlive._getOwner_native())
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}
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}
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}
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public class ReferenceWritableKeyPath<Root, Value>: WritableKeyPath<Root, Value> {
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// MARK: Implementation detail
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final override class var kind: Kind { return .reference }
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final override func projectMutableAddress(from base: UnsafePointer<Root>)
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-> (pointer: UnsafeMutablePointer<Value>, owner: Builtin.NativeObject) {
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// Since we're a ReferenceWritableKeyPath, we know we don't mutate the base in
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// practice.
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return projectMutableAddress(from: base.pointee)
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}
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final func projectMutableAddress(from origBase: Root)
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-> (pointer: UnsafeMutablePointer<Value>, owner: Builtin.NativeObject) {
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var keepAlive: [AnyObject] = []
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var address: UnsafeMutablePointer<Value> = withBuffer {
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var buffer = $0
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// Project out the reference prefix.
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var base: Any = origBase
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while buffer.hasReferencePrefix {
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let (rawComponent, optNextType) = buffer.next()
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_sanityCheck(optNextType != nil,
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"reference prefix should not go to end of buffer")
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let nextType = optNextType.unsafelyUnwrapped
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func project<NewValue>(_: NewValue.Type) -> Any {
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func project2<CurValue>(_ base: CurValue) -> Any {
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return rawComponent.projectReadOnly(base) as NewValue
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}
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return _openExistential(base, do: project2)
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}
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base = _openExistential(nextType, do: project)
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}
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// Start formal access to the mutable value, based on the final base
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// value.
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func formalMutation<MutationRoot>(_ base: MutationRoot)
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-> UnsafeMutablePointer<Value> {
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var base2 = base
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return withUnsafeBytes(of: &base2) { baseBytes in
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var p = baseBytes.baseAddress.unsafelyUnwrapped
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var curType: Any.Type = MutationRoot.self
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while true {
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let (rawComponent, optNextType) = buffer.next()
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let nextType = optNextType ?? Value.self
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func project<CurValue>(_: CurValue.Type) {
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func project2<NewValue>(_: NewValue.Type) {
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p = rawComponent.projectMutableAddress(p,
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from: CurValue.self,
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to: NewValue.self,
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isRoot: p == baseBytes.baseAddress,
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keepAlive: &keepAlive)
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}
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_openExistential(nextType, do: project2)
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}
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_openExistential(curType, do: project)
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if optNextType == nil { break }
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curType = nextType
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}
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let typedPointer = p.assumingMemoryBound(to: Value.self)
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return UnsafeMutablePointer(mutating: typedPointer)
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}
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}
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return _openExistential(base, do: formalMutation)
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}
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return (address, keepAlive._getOwner_native())
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}
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}
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// MARK: Implementation details
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enum KeyPathComponentKind {
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/// The keypath projects within the storage of the outer value, like a
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/// stored property in a struct.
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case `struct`
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/// The keypath projects from the referenced pointer, like a
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/// stored property in a class.
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case `class`
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/// The keypath optional-chains, returning nil immediately if the input is
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/// nil, or else proceeding by projecting the value inside.
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case optionalChain
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/// The keypath optional-forces, trapping if the input is
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/// nil, or else proceeding by projecting the value inside.
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case optionalForce
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/// The keypath wraps a value in an optional.
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case optionalWrap
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}
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enum KeyPathComponent: Hashable {
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struct RawAccessor {
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var rawCode: Builtin.RawPointer
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var rawContext: Builtin.NativeObject?
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}
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/// The keypath projects within the storage of the outer value, like a
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/// stored property in a struct.
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case `struct`(offset: Int)
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/// The keypath projects from the referenced pointer, like a
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/// stored property in a class.
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case `class`(offset: Int)
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/// The keypath optional-chains, returning nil immediately if the input is
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/// nil, or else proceeding by projecting the value inside.
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case optionalChain
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/// The keypath optional-forces, trapping if the input is
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/// nil, or else proceeding by projecting the value inside.
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case optionalForce
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/// The keypath wraps a value in an optional.
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case optionalWrap
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static func ==(a: KeyPathComponent, b: KeyPathComponent) -> Bool {
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switch (a, b) {
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case (.struct(offset: let a), .struct(offset: let b)),
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(.class (offset: let a), .class (offset: let b)):
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return a == b
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case (.optionalChain, .optionalChain),
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(.optionalForce, .optionalForce),
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(.optionalWrap, .optionalWrap):
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return true
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case (.struct, _),
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(.class, _),
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(.optionalChain, _),
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(.optionalForce, _),
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(.optionalWrap, _):
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return false
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}
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}
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var hashValue: Int {
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var hash: Int = 0
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switch self {
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case .struct(offset: let a):
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hash ^= _mixInt(0)
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hash ^= _mixInt(a)
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case .class(offset: let b):
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hash ^= _mixInt(1)
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hash ^= _mixInt(b)
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case .optionalChain:
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hash ^= _mixInt(2)
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case .optionalForce:
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hash ^= _mixInt(3)
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case .optionalWrap:
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hash ^= _mixInt(4)
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}
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return hash
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}
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}
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struct RawKeyPathComponent {
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var header: Header
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var body: UnsafeRawBufferPointer
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struct Header {
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static var payloadMask: UInt32 {
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return _SwiftKeyPathComponentHeader_PayloadMask
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}
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static var discriminatorMask: UInt32 {
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return _SwiftKeyPathComponentHeader_DiscriminatorMask
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}
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static var discriminatorShift: UInt32 {
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return _SwiftKeyPathComponentHeader_DiscriminatorShift
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}
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static var structTag: UInt32 {
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return _SwiftKeyPathComponentHeader_StructTag
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}
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static var classTag: UInt32 {
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return _SwiftKeyPathComponentHeader_ClassTag
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}
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static var optionalTag: UInt32 {
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return _SwiftKeyPathComponentHeader_OptionalTag
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}
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static var optionalChainPayload: UInt32 {
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return _SwiftKeyPathComponentHeader_OptionalChainPayload
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}
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static var optionalWrapPayload: UInt32 {
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return _SwiftKeyPathComponentHeader_OptionalWrapPayload
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}
|
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static var optionalForcePayload: UInt32 {
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return _SwiftKeyPathComponentHeader_OptionalForcePayload
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}
|
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static var endOfReferencePrefixFlag: UInt32 {
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return _SwiftKeyPathComponentHeader_EndOfReferencePrefixFlag
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}
|
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static var outOfLineOffsetPayload: UInt32 {
|
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return _SwiftKeyPathComponentHeader_OutOfLineOffsetPayload
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}
|
|
static var unresolvedOffsetPayload: UInt32 {
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return _SwiftKeyPathComponentHeader_UnresolvedOffsetPayload
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}
|
|
|
|
var _value: UInt32
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|
|
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var discriminator: UInt32 {
|
|
return (_value & Header.discriminatorMask) >> Header.discriminatorShift
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}
|
|
var payload: UInt32 {
|
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get {
|
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return _value & Header.payloadMask
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}
|
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set {
|
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_sanityCheck(newValue & Header.payloadMask == newValue,
|
|
"payload too big")
|
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_value = _value & ~Header.payloadMask | newValue
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}
|
|
}
|
|
var endOfReferencePrefix: Bool {
|
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get {
|
|
return _value & Header.endOfReferencePrefixFlag != 0
|
|
}
|
|
set {
|
|
if newValue {
|
|
_value |= Header.endOfReferencePrefixFlag
|
|
} else {
|
|
_value &= ~Header.endOfReferencePrefixFlag
|
|
}
|
|
}
|
|
}
|
|
|
|
var kind: KeyPathComponentKind {
|
|
switch (discriminator, payload) {
|
|
case (Header.structTag, _):
|
|
return .struct
|
|
case (Header.classTag, _):
|
|
return .class
|
|
case (Header.optionalTag, Header.optionalChainPayload):
|
|
return .optionalChain
|
|
case (Header.optionalTag, Header.optionalWrapPayload):
|
|
return .optionalWrap
|
|
case (Header.optionalTag, Header.optionalForcePayload):
|
|
return .optionalForce
|
|
default:
|
|
_sanityCheckFailure("invalid header")
|
|
}
|
|
}
|
|
|
|
var bodySize: Int {
|
|
switch kind {
|
|
case .struct, .class:
|
|
if payload == Header.payloadMask { return 4 } // overflowed
|
|
return 0
|
|
case .optionalChain, .optionalForce, .optionalWrap:
|
|
return 0
|
|
}
|
|
}
|
|
|
|
var isTrivial: Bool {
|
|
switch kind {
|
|
case .struct, .class, .optionalChain, .optionalForce, .optionalWrap:
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
|
|
var _structOrClassOffset: Int {
|
|
_sanityCheck(header.kind == .struct || header.kind == .class,
|
|
"no offset for this kind")
|
|
// An offset too large to fit inline is represented by a signal and stored
|
|
// in the body.
|
|
if header.payload == Header.outOfLineOffsetPayload {
|
|
// Offset overflowed into body
|
|
_sanityCheck(body.count >= MemoryLayout<UInt32>.size,
|
|
"component not big enough")
|
|
return Int(body.load(as: UInt32.self))
|
|
}
|
|
return Int(header.payload)
|
|
}
|
|
|
|
var value: KeyPathComponent {
|
|
switch header.kind {
|
|
case .struct:
|
|
return .struct(offset: _structOrClassOffset)
|
|
case .class:
|
|
return .class(offset: _structOrClassOffset)
|
|
case .optionalChain:
|
|
return .optionalChain
|
|
case .optionalForce:
|
|
return .optionalForce
|
|
case .optionalWrap:
|
|
return .optionalWrap
|
|
}
|
|
}
|
|
|
|
func destroy() {
|
|
switch header.kind {
|
|
case .struct,
|
|
.class,
|
|
.optionalChain,
|
|
.optionalForce,
|
|
.optionalWrap:
|
|
// trivial
|
|
return
|
|
}
|
|
}
|
|
|
|
func clone(into buffer: inout UnsafeMutableRawBufferPointer,
|
|
endOfReferencePrefix: Bool) {
|
|
var newHeader = header
|
|
newHeader.endOfReferencePrefix = endOfReferencePrefix
|
|
|
|
var componentSize = MemoryLayout<Header>.size
|
|
buffer.storeBytes(of: newHeader, as: Header.self)
|
|
switch header.kind {
|
|
case .struct,
|
|
.class:
|
|
if header.payload == Header.payloadMask {
|
|
let overflowOffset = body.load(as: UInt32.self)
|
|
buffer.storeBytes(of: overflowOffset, toByteOffset: 4,
|
|
as: UInt32.self)
|
|
componentSize += 4
|
|
}
|
|
case .optionalChain,
|
|
.optionalForce,
|
|
.optionalWrap:
|
|
break
|
|
}
|
|
_sanityCheck(buffer.count >= componentSize)
|
|
buffer = UnsafeMutableRawBufferPointer(
|
|
start: buffer.baseAddress.unsafelyUnwrapped + componentSize,
|
|
count: buffer.count - componentSize
|
|
)
|
|
}
|
|
|
|
func projectReadOnly<CurValue, NewValue>(_ base: CurValue) -> NewValue {
|
|
switch value {
|
|
case .struct(let offset):
|
|
var base2 = base
|
|
return withUnsafeBytes(of: &base2) {
|
|
let p = $0.baseAddress.unsafelyUnwrapped.advanced(by: offset)
|
|
// The contents of the struct should be well-typed, so we can assume
|
|
// typed memory here.
|
|
return p.assumingMemoryBound(to: NewValue.self).pointee
|
|
}
|
|
|
|
case .class(let offset):
|
|
_sanityCheck(CurValue.self is AnyObject.Type,
|
|
"base is not a class")
|
|
let baseObj = unsafeBitCast(base, to: AnyObject.self)
|
|
let basePtr = UnsafeRawPointer(Builtin.bridgeToRawPointer(baseObj))
|
|
defer { _fixLifetime(baseObj) }
|
|
return basePtr.advanced(by: offset)
|
|
.assumingMemoryBound(to: NewValue.self)
|
|
.pointee
|
|
|
|
case .optionalChain:
|
|
fatalError("TODO")
|
|
|
|
case .optionalForce:
|
|
fatalError("TODO")
|
|
|
|
case .optionalWrap:
|
|
fatalError("TODO")
|
|
}
|
|
}
|
|
|
|
func projectMutableAddress<CurValue, NewValue>(
|
|
_ base: UnsafeRawPointer,
|
|
from _: CurValue.Type,
|
|
to _: NewValue.Type,
|
|
isRoot: Bool,
|
|
keepAlive: inout [AnyObject]
|
|
) -> UnsafeRawPointer {
|
|
switch value {
|
|
case .struct(let offset):
|
|
return base.advanced(by: offset)
|
|
case .class(let offset):
|
|
// A class dereference should only occur at the root of a mutation,
|
|
// since otherwise it would be part of the reference prefix.
|
|
_sanityCheck(isRoot,
|
|
"class component should not appear in the middle of mutation")
|
|
// AnyObject memory can alias any class reference memory, so we can
|
|
// assume type here
|
|
let object = base.assumingMemoryBound(to: AnyObject.self).pointee
|
|
// The base ought to be kept alive for the duration of the derived access
|
|
keepAlive.append(object)
|
|
return UnsafeRawPointer(Builtin.bridgeToRawPointer(object))
|
|
.advanced(by: offset)
|
|
|
|
case .optionalForce:
|
|
fatalError("TODO")
|
|
|
|
case .optionalChain, .optionalWrap:
|
|
_sanityCheckFailure("not a mutable key path component")
|
|
}
|
|
}
|
|
}
|
|
|
|
internal struct KeyPathBuffer {
|
|
var data: UnsafeRawBufferPointer
|
|
var trivial: Bool
|
|
var hasReferencePrefix: Bool
|
|
|
|
var mutableData: UnsafeMutableRawBufferPointer {
|
|
return UnsafeMutableRawBufferPointer(mutating: data)
|
|
}
|
|
|
|
struct Header {
|
|
var _value: UInt32
|
|
|
|
static var sizeMask: UInt32 {
|
|
return _SwiftKeyPathBufferHeader_SizeMask
|
|
}
|
|
static var reservedMask: UInt32 {
|
|
return _SwiftKeyPathBufferHeader_ReservedMask
|
|
}
|
|
static var trivialFlag: UInt32 {
|
|
return _SwiftKeyPathBufferHeader_TrivialFlag
|
|
}
|
|
static var hasReferencePrefixFlag: UInt32 {
|
|
return _SwiftKeyPathBufferHeader_HasReferencePrefixFlag
|
|
}
|
|
|
|
init(size: Int, trivial: Bool, hasReferencePrefix: Bool) {
|
|
_sanityCheck(size <= Int(Header.sizeMask), "key path too big")
|
|
_value = UInt32(size)
|
|
| (trivial ? Header.trivialFlag : 0)
|
|
| (hasReferencePrefix ? Header.hasReferencePrefixFlag : 0)
|
|
}
|
|
|
|
var size: Int { return Int(_value & Header.sizeMask) }
|
|
var trivial: Bool { return _value & Header.trivialFlag != 0 }
|
|
var hasReferencePrefix: Bool {
|
|
get {
|
|
return _value & Header.hasReferencePrefixFlag != 0
|
|
}
|
|
set {
|
|
if newValue {
|
|
_value |= Header.hasReferencePrefixFlag
|
|
} else {
|
|
_value &= ~Header.hasReferencePrefixFlag
|
|
}
|
|
}
|
|
}
|
|
|
|
// In a key path pattern, the "trivial" flag is used to indicate
|
|
// "instantiable in-line"
|
|
var instantiableInLine: Bool {
|
|
return trivial
|
|
}
|
|
|
|
func validateReservedBits() {
|
|
_precondition(_value & Header.reservedMask == 0,
|
|
"reserved bits set to an unexpected bit pattern")
|
|
}
|
|
}
|
|
|
|
init(base: UnsafeRawPointer) {
|
|
let header = base.load(as: Header.self)
|
|
data = UnsafeRawBufferPointer(
|
|
start: base + MemoryLayout<Header>.size,
|
|
count: header.size
|
|
)
|
|
trivial = header.trivial
|
|
hasReferencePrefix = header.hasReferencePrefix
|
|
}
|
|
|
|
func destroy() {
|
|
if trivial { return }
|
|
fatalError("TODO")
|
|
}
|
|
|
|
mutating func next() -> (RawKeyPathComponent, Any.Type?) {
|
|
let header = pop(RawKeyPathComponent.Header.self)
|
|
// Track if this is the last component of the reference prefix.
|
|
if header.endOfReferencePrefix {
|
|
_sanityCheck(self.hasReferencePrefix,
|
|
"beginMutation marker in non-reference-writable key path?")
|
|
self.hasReferencePrefix = false
|
|
}
|
|
|
|
let body: UnsafeRawBufferPointer
|
|
let size = header.bodySize
|
|
if size != 0 {
|
|
body = popRaw(size)
|
|
} else {
|
|
body = UnsafeRawBufferPointer(start: nil, count: 0)
|
|
}
|
|
let component = RawKeyPathComponent(header: header, body: body)
|
|
|
|
// fetch type, which is in the buffer unless it's the final component
|
|
let nextType: Any.Type?
|
|
if data.count == 0 {
|
|
nextType = nil
|
|
} else {
|
|
if MemoryLayout<Any.Type>.size == 8 {
|
|
// Words in the key path buffer are 32-bit aligned
|
|
nextType = unsafeBitCast(pop((Int32, Int32).self),
|
|
to: Any.Type.self)
|
|
} else if MemoryLayout<Any.Type>.size == 4 {
|
|
nextType = pop(Any.Type.self)
|
|
} else {
|
|
_sanityCheckFailure("unexpected word size")
|
|
}
|
|
}
|
|
return (component, nextType)
|
|
}
|
|
|
|
mutating func pop<T>(_ type: T.Type) -> T {
|
|
let raw = popRaw(MemoryLayout<T>.size)
|
|
return raw.load(as: type)
|
|
}
|
|
mutating func popRaw(_ size: Int) -> UnsafeRawBufferPointer {
|
|
_sanityCheck(data.count >= size,
|
|
"not enough space for next component?")
|
|
let result = UnsafeRawBufferPointer(start: data.baseAddress, count: size)
|
|
data = UnsafeRawBufferPointer(
|
|
start: data.baseAddress.unsafelyUnwrapped + size,
|
|
count: data.count - size
|
|
)
|
|
return result
|
|
}
|
|
}
|
|
|
|
public struct _KeyPathBase<T> {
|
|
public var base: T
|
|
public init(base: T) { self.base = base }
|
|
|
|
// TODO: These subscripts ought to sit on `Any`
|
|
public subscript<U>(keyPath: KeyPath<T, U>) -> U {
|
|
return keyPath.projectReadOnly(from: base)
|
|
}
|
|
|
|
public subscript<U>(keyPath: WritableKeyPath<T, U>) -> U {
|
|
get {
|
|
return keyPath.projectReadOnly(from: base)
|
|
}
|
|
mutableAddressWithNativeOwner {
|
|
// The soundness of this `addressof` operation relies on the returned
|
|
// address from an address only being used during a single formal access
|
|
// of `self` (IOW, there's no end of the formal access between
|
|
// `materializeForSet` and its continuation).
|
|
let basePtr = UnsafeMutablePointer<T>(Builtin.addressof(&base))
|
|
return keyPath.projectMutableAddress(from: basePtr)
|
|
}
|
|
}
|
|
|
|
public subscript<U>(keyPath: ReferenceWritableKeyPath<T, U>) -> U {
|
|
get {
|
|
return keyPath.projectReadOnly(from: base)
|
|
}
|
|
nonmutating mutableAddressWithNativeOwner {
|
|
return keyPath.projectMutableAddress(from: base)
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: Appending type system
|
|
|
|
// FIXME(ABI): The type relationships between KeyPath append operands are tricky
|
|
// and don't interact well with our overriding rules. Hack things by injecting
|
|
// a bunch of `appending` overloads as protocol extensions so they aren't
|
|
// constrained by being overrides, and so that we can use exact-type constraints
|
|
// on `Self` to prevent dynamically-typed methods from being inherited by
|
|
// statically-typed key paths.
|
|
public protocol _AppendKeyPath {}
|
|
|
|
extension _AppendKeyPath where Self == AnyKeyPath {
|
|
public func appending(path: AnyKeyPath) -> AnyKeyPath? {
|
|
return _tryToAppendKeyPaths(root: self, leaf: path)
|
|
}
|
|
}
|
|
|
|
extension _AppendKeyPath /* where Self == PartialKeyPath<T> */ {
|
|
public func appending<Root>(path: AnyKeyPath) -> PartialKeyPath<Root>?
|
|
where Self == PartialKeyPath<Root> {
|
|
return _tryToAppendKeyPaths(root: self, leaf: path)
|
|
}
|
|
|
|
public func appending<Root, AppendedRoot, AppendedValue>(
|
|
path: KeyPath<AppendedRoot, AppendedValue>
|
|
) -> KeyPath<Root, AppendedValue>?
|
|
where Self == PartialKeyPath<Root> {
|
|
return _tryToAppendKeyPaths(root: self, leaf: path)
|
|
}
|
|
|
|
public func appending<Root, AppendedRoot, AppendedValue>(
|
|
path: ReferenceWritableKeyPath<AppendedRoot, AppendedValue>
|
|
) -> ReferenceWritableKeyPath<Root, AppendedValue>?
|
|
where Self == PartialKeyPath<Root> {
|
|
return _tryToAppendKeyPaths(root: self, leaf: path)
|
|
}
|
|
}
|
|
|
|
extension _AppendKeyPath /* where Self == KeyPath<T,U> */ {
|
|
public func appending<Root, Value, AppendedValue>(
|
|
path: KeyPath<Value, AppendedValue>
|
|
) -> KeyPath<Root, AppendedValue>
|
|
where Self: KeyPath<Root, Value> {
|
|
return _appendingKeyPaths(root: self, leaf: path)
|
|
}
|
|
|
|
/* TODO
|
|
public func appending<Root, Value, Leaf>(
|
|
path: Leaf,
|
|
// FIXME: Satisfy "Value generic param not used in signature" constraint
|
|
_: Value.Type = Value.self
|
|
) -> PartialKeyPath<Root>?
|
|
where Self: KeyPath<Root, Value>, Leaf == AnyKeyPath {
|
|
return _tryToAppendKeyPaths(root: self, leaf: path)
|
|
}
|
|
*/
|
|
|
|
public func appending<Root, Value, AppendedValue>(
|
|
path: ReferenceWritableKeyPath<Value, AppendedValue>
|
|
) -> ReferenceWritableKeyPath<Root, AppendedValue>
|
|
where Self == KeyPath<Root, Value> {
|
|
return _appendingKeyPaths(root: self, leaf: path)
|
|
}
|
|
}
|
|
|
|
extension _AppendKeyPath /* where Self == WritableKeyPath<T,U> */ {
|
|
public func appending<Root, Value, AppendedValue>(
|
|
path: WritableKeyPath<Value, AppendedValue>
|
|
) -> WritableKeyPath<Root, AppendedValue>
|
|
where Self == WritableKeyPath<Root, Value> {
|
|
return _appendingKeyPaths(root: self, leaf: path)
|
|
}
|
|
|
|
public func appending<Root, Value, AppendedValue>(
|
|
path: ReferenceWritableKeyPath<Value, AppendedValue>
|
|
) -> ReferenceWritableKeyPath<Root, AppendedValue>
|
|
where Self == WritableKeyPath<Root, Value> {
|
|
return _appendingKeyPaths(root: self, leaf: path)
|
|
}
|
|
}
|
|
|
|
extension _AppendKeyPath /* where Self == ReferenceWritableKeyPath<T,U> */ {
|
|
public func appending<Root, Value, AppendedValue>(
|
|
path: WritableKeyPath<Value, AppendedValue>
|
|
) -> ReferenceWritableKeyPath<Root, AppendedValue>
|
|
where Self == ReferenceWritableKeyPath<Root, Value> {
|
|
return _appendingKeyPaths(root: self, leaf: path)
|
|
}
|
|
}
|
|
|
|
// internal-with-availability
|
|
public func _tryToAppendKeyPaths<Result: AnyKeyPath>(
|
|
root: AnyKeyPath,
|
|
leaf: AnyKeyPath
|
|
) -> Result? {
|
|
let (rootRoot, rootValue) = type(of: root)._rootAndValueType
|
|
let (leafRoot, leafValue) = type(of: leaf)._rootAndValueType
|
|
|
|
if rootValue != leafRoot {
|
|
return nil
|
|
}
|
|
|
|
func open<Root>(_: Root.Type) -> Result {
|
|
func open2<Value>(_: Value.Type) -> Result {
|
|
func open3<AppendedValue>(_: AppendedValue.Type) -> Result {
|
|
let typedRoot = unsafeDowncast(root, to: KeyPath<Root, Value>.self)
|
|
let typedLeaf = unsafeDowncast(leaf,
|
|
to: KeyPath<Value, AppendedValue>.self)
|
|
let result = _appendingKeyPaths(root: typedRoot, leaf: typedLeaf)
|
|
return unsafeDowncast(result, to: Result.self)
|
|
}
|
|
return _openExistential(leafValue, do: open3)
|
|
}
|
|
return _openExistential(rootValue, do: open2)
|
|
}
|
|
return _openExistential(rootRoot, do: open)
|
|
}
|
|
|
|
// internal-with-availability
|
|
public func _appendingKeyPaths<
|
|
Root, Value, AppendedValue,
|
|
Result: KeyPath<Root, AppendedValue>
|
|
>(
|
|
root: KeyPath<Root, Value>,
|
|
leaf: KeyPath<Value, AppendedValue>
|
|
) -> Result {
|
|
let resultTy = type(of: root).appendedType(with: type(of: leaf))
|
|
return root.withBuffer {
|
|
var rootBuffer = $0
|
|
return leaf.withBuffer {
|
|
var leafBuffer = $0
|
|
// Result buffer has room for both key paths' components, plus the
|
|
// header, plus space for the middle type.
|
|
let resultSize = rootBuffer.data.count + leafBuffer.data.count
|
|
+ MemoryLayout<KeyPathBuffer.Header>.size
|
|
+ MemoryLayout<Int>.size
|
|
let result = resultTy._create(capacityInBytes: resultSize) {
|
|
var destBuffer = $0
|
|
|
|
func pushRaw(_ count: Int) {
|
|
_sanityCheck(destBuffer.count >= count)
|
|
destBuffer = UnsafeMutableRawBufferPointer(
|
|
start: destBuffer.baseAddress.unsafelyUnwrapped + count,
|
|
count: destBuffer.count - count
|
|
)
|
|
}
|
|
func pushType(_ type: Any.Type) {
|
|
let intSize = MemoryLayout<Int>.size
|
|
_sanityCheck(destBuffer.count >= intSize)
|
|
if intSize == 8 {
|
|
let words = unsafeBitCast(type, to: (UInt32, UInt32).self)
|
|
destBuffer.storeBytes(of: words.0,
|
|
as: UInt32.self)
|
|
destBuffer.storeBytes(of: words.1, toByteOffset: 4,
|
|
as: UInt32.self)
|
|
} else if intSize == 4 {
|
|
destBuffer.storeBytes(of: type, as: Any.Type.self)
|
|
} else {
|
|
_sanityCheckFailure("unsupported architecture")
|
|
}
|
|
pushRaw(intSize)
|
|
}
|
|
|
|
// Save space for the header.
|
|
let leafIsReferenceWritable = type(of: leaf).kind == .reference
|
|
let header = KeyPathBuffer.Header(
|
|
size: resultSize - MemoryLayout<KeyPathBuffer.Header>.size,
|
|
trivial: rootBuffer.trivial && leafBuffer.trivial,
|
|
hasReferencePrefix: rootBuffer.hasReferencePrefix
|
|
|| leafIsReferenceWritable
|
|
)
|
|
destBuffer.storeBytes(of: header, as: KeyPathBuffer.Header.self)
|
|
pushRaw(MemoryLayout<KeyPathBuffer.Header>.size)
|
|
|
|
let leafHasReferencePrefix = leafBuffer.hasReferencePrefix
|
|
|
|
// Clone the root components into the buffer.
|
|
|
|
while true {
|
|
let (component, type) = rootBuffer.next()
|
|
let isLast = type == nil
|
|
// If the leaf appended path has a reference prefix, then the
|
|
// entire root is part of the reference prefix.
|
|
let endOfReferencePrefix: Bool
|
|
if leafHasReferencePrefix {
|
|
endOfReferencePrefix = false
|
|
} else if isLast && leafIsReferenceWritable {
|
|
endOfReferencePrefix = true
|
|
} else {
|
|
endOfReferencePrefix = component.header.endOfReferencePrefix
|
|
}
|
|
|
|
component.clone(
|
|
into: &destBuffer,
|
|
endOfReferencePrefix: endOfReferencePrefix
|
|
)
|
|
if let type = type {
|
|
pushType(type)
|
|
} else {
|
|
// Insert our endpoint type between the root and leaf components.
|
|
pushType(Value.self)
|
|
break
|
|
}
|
|
}
|
|
|
|
// Clone the leaf components into the buffer.
|
|
while true {
|
|
let (component, type) = leafBuffer.next()
|
|
|
|
component.clone(
|
|
into: &destBuffer,
|
|
endOfReferencePrefix: component.header.endOfReferencePrefix
|
|
)
|
|
|
|
if let type = type {
|
|
pushType(type)
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
|
|
_sanityCheck(destBuffer.count == 0,
|
|
"did not fill entire result buffer")
|
|
}
|
|
return unsafeDowncast(result, to: Result.self)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Runtime entry point to instantiate a key path object.
|
|
@_cdecl("swift_getKeyPath")
|
|
public func swift_getKeyPath(pattern: UnsafeMutableRawPointer,
|
|
arguments: UnsafeRawPointer)
|
|
-> UnsafeRawPointer {
|
|
// The key path pattern is laid out like a key path object, with a few
|
|
// modifications:
|
|
// - Instead of the two-word object header with isa and refcount, two
|
|
// pointers to metadata accessors are provided for the root and leaf
|
|
// value types of the key path.
|
|
// - The header reuses the "trivial" bit to mean "instantiable in-line",
|
|
// meaning that the key path described by this pattern has no contextually
|
|
// dependent parts (no dependence on generic parameters, subscript indexes,
|
|
// etc.), so it can be set up as a global object once. (The resulting
|
|
// global object will itself always have the "trivial" bit set, since it
|
|
// never needs to be destroyed.)
|
|
// - Components may have unresolved forms that require instantiation.
|
|
// - The component type metadata pointers are unresolved, and instead
|
|
// point to accessor functions that instantiate the metadata.
|
|
//
|
|
// The pattern never precomputes the capabilities of the key path (readonly/
|
|
// writable/reference-writable), nor does it encode the reference prefix.
|
|
// These are resolved dynamically, so that they always reflect the dynamic
|
|
// capability of the properties involved.
|
|
let oncePtr = pattern
|
|
let objectPtr = pattern.advanced(by: MemoryLayout<Int>.size)
|
|
let bufferPtr = objectPtr.advanced(by: MemoryLayout<HeapObject>.size)
|
|
|
|
// If the pattern is instantiable in-line, do a dispatch_once to
|
|
// initialize it. (The resulting object will still have the collocated
|
|
// "trivial" bit set, since a global object never needs destruction.)
|
|
let bufferHeader = bufferPtr.load(as: KeyPathBuffer.Header.self)
|
|
bufferHeader.validateReservedBits()
|
|
|
|
if bufferHeader.instantiableInLine {
|
|
Builtin.onceWithContext(oncePtr._rawValue, _getKeyPath_instantiatedInline,
|
|
objectPtr._rawValue)
|
|
// Return the instantiated object at +1.
|
|
// TODO: This will be unnecessary once we support global objects with inert
|
|
// refcounting.
|
|
let object = Unmanaged<AnyKeyPath>.fromOpaque(objectPtr)
|
|
_ = object.retain()
|
|
return UnsafeRawPointer(objectPtr)
|
|
}
|
|
// TODO: Handle cases that require per-instance instantiation
|
|
fatalError("not implemented")
|
|
}
|
|
|
|
internal func _getKeyPath_instantiatedInline(
|
|
_ objectRawPtr: Builtin.RawPointer
|
|
) {
|
|
let objectPtr = UnsafeMutableRawPointer(objectRawPtr)
|
|
let bufferPtr = objectPtr.advanced(by: MemoryLayout<HeapObject>.size)
|
|
var buffer = KeyPathBuffer(base: bufferPtr)
|
|
|
|
// Resolve the root and leaf types.
|
|
typealias MetadataAccessor = @convention(c) () -> UnsafeRawPointer
|
|
let rootAccessor = objectPtr.load(as: MetadataAccessor.self)
|
|
let leafAccessor = objectPtr.load(fromByteOffset: MemoryLayout<Int>.size,
|
|
as: MetadataAccessor.self)
|
|
|
|
let root = unsafeBitCast(rootAccessor(), to: Any.Type.self)
|
|
let leaf = unsafeBitCast(leafAccessor(), to: Any.Type.self)
|
|
|
|
// Assume the key path is writable until proven otherwise
|
|
var capability: KeyPathKind = .value
|
|
// Track where the reference prefix begins
|
|
var endOfReferencePrefixComponent: UnsafeRawPointer? = nil
|
|
var previousComponentAddr: UnsafeRawPointer? = nil
|
|
|
|
// Instantiate components that need it.
|
|
while true {
|
|
let componentAddr = buffer.data.baseAddress.unsafelyUnwrapped
|
|
let header = buffer.pop(RawKeyPathComponent.Header.self)
|
|
|
|
func tryToResolveOffset() {
|
|
if header.payload == RawKeyPathComponent.Header.unresolvedOffsetPayload {
|
|
// TODO: Look up offset in type metadata
|
|
fatalError("not implemented")
|
|
}
|
|
if header.payload == RawKeyPathComponent.Header.outOfLineOffsetPayload {
|
|
_ = buffer.pop(UInt32.self)
|
|
}
|
|
}
|
|
|
|
switch header.kind {
|
|
case .struct:
|
|
// The offset may need to be resolved dynamically.
|
|
tryToResolveOffset()
|
|
case .class:
|
|
// The offset may need to be resolved dynamically.
|
|
tryToResolveOffset()
|
|
// Crossing a class can end the reference prefix, and makes the following
|
|
// key path potentially reference-writable.
|
|
endOfReferencePrefixComponent = previousComponentAddr
|
|
capability = .reference
|
|
case .optionalChain,
|
|
.optionalWrap,
|
|
.optionalForce:
|
|
// No instantiation necessary.
|
|
break
|
|
}
|
|
|
|
// Break if this is the last component.
|
|
if buffer.data.count == 0 { break }
|
|
|
|
// Resolve the component type.
|
|
if MemoryLayout<Int>.size == 4 {
|
|
let componentTyAccessor = buffer.data.load(as: MetadataAccessor.self)
|
|
let componentTy = unsafeBitCast(componentTyAccessor, to: Any.Type.self)
|
|
buffer.mutableData.storeBytes(of: componentTy, as: Any.Type.self)
|
|
} else if MemoryLayout<Int>.size == 8 {
|
|
let componentTyAccessorWords = buffer.data.load(as: (UInt32,UInt32).self)
|
|
let componentTyAccessor = unsafeBitCast(componentTyAccessorWords,
|
|
to: MetadataAccessor.self)
|
|
let componentTyWords = unsafeBitCast(componentTyAccessor(),
|
|
to: (UInt32, UInt32).self)
|
|
buffer.mutableData.storeBytes(of: componentTyWords,
|
|
as: (UInt32,UInt32).self)
|
|
} else {
|
|
fatalError("unsupported architecture")
|
|
}
|
|
_ = buffer.pop(Int.self)
|
|
previousComponentAddr = componentAddr
|
|
}
|
|
|
|
// Set up the reference prefix if there is one.
|
|
if let endOfReferencePrefixComponent = endOfReferencePrefixComponent {
|
|
var bufferHeader = bufferPtr.load(as: KeyPathBuffer.Header.self)
|
|
bufferHeader.hasReferencePrefix = true
|
|
bufferPtr.storeBytes(of: bufferHeader, as: KeyPathBuffer.Header.self)
|
|
|
|
var componentHeader = endOfReferencePrefixComponent
|
|
.load(as: RawKeyPathComponent.Header.self)
|
|
componentHeader.endOfReferencePrefix = true
|
|
UnsafeMutableRawPointer(mutating: endOfReferencePrefixComponent)
|
|
.storeBytes(of: componentHeader,
|
|
as: RawKeyPathComponent.Header.self)
|
|
}
|
|
|
|
// Figure out the class type that the object will have based on its
|
|
// dynamic capability.
|
|
func openRoot<Root>(_: Root.Type) -> AnyKeyPath.Type {
|
|
func openLeaf<Leaf>(_: Leaf.Type) -> AnyKeyPath.Type {
|
|
switch capability {
|
|
case .readOnly:
|
|
return KeyPath<Root, Leaf>.self
|
|
case .value:
|
|
return WritableKeyPath<Root, Leaf>.self
|
|
case .reference:
|
|
return ReferenceWritableKeyPath<Root, Leaf>.self
|
|
}
|
|
}
|
|
return _openExistential(leaf, do: openLeaf)
|
|
}
|
|
let classTy = _openExistential(root, do: openRoot)
|
|
|
|
_swift_instantiateInertHeapObject(
|
|
objectPtr,
|
|
unsafeBitCast(classTy, to: OpaquePointer.self)
|
|
)
|
|
}
|