Merge branch 'main' into filip-sakel-SE0293-gardening

Author: filip-sakel

CHANGELOG.md

@@ -1,34 +1,91 @@
 CHANGELOG
 =========
 
-<details>
-<summary>Note: This is in reverse chronological order, so newer entries are added to the top.</summary>
-
-| Version                | Released   | Toolchain   |
-| :--------------------- | :--------- | :---------- |
-| [Swift 5.5](#swift-55) |            |             |
-| [Swift 5.4](#swift-54) |            |             |
-| [Swift 5.3](#swift-53) | 2020-09-16 | Xcode 12.0  |
-| [Swift 5.2](#swift-52) | 2020-03-24 | Xcode 11.4  |
-| [Swift 5.1](#swift-51) | 2019-09-20 | Xcode 11.0  |
-| [Swift 5.0](#swift-50) | 2019-03-25 | Xcode 10.2  |
-| [Swift 4.2](#swift-42) | 2018-09-17 | Xcode 10.0  |
-| [Swift 4.1](#swift-41) | 2018-03-29 | Xcode 9.3   |
-| [Swift 4.0](#swift-40) | 2017-09-19 | Xcode 9.0   |
-| [Swift 3.1](#swift-31) | 2017-03-27 | Xcode 8.3   |
-| [Swift 3.0](#swift-30) | 2016-09-13 | Xcode 8.0   |
-| [Swift 2.2](#swift-22) | 2016-03-21 | Xcode 7.3   |
-| [Swift 2.1](#swift-21) | 2015-10-21 | Xcode 7.1   |
-| [Swift 2.0](#swift-20) | 2015-09-17 | Xcode 7.0   |
-| [Swift 1.2](#swift-12) | 2015-04-08 | Xcode 6.3   |
-| [Swift 1.1](#swift-11) | 2014-12-02 | Xcode 6.1.1 |
-| [Swift 1.0](#swift-10) | 2014-09-15 | Xcode 6.0   |
-
-</details>
+_**Note:** This is in reverse chronological order, so newer entries are added to the top._
 
 Swift 5.5
 ---------
 
+* Type names are no longer allowed as an argument to a subscript parameter that expects a metatype type
+
+```swift
+struct MyValue {
+}
+
+struct MyStruct {
+  subscript(a: MyValue.Type) -> Int { get { ... } }
+}
+
+func test(obj: MyStruct) {
+  let _ = obj[MyValue]
+}
+```
+
+Accepting subscripts with `MyValue` as an argument was an oversight because `MyValue` requires explicit `.self`
+to reference its metatype, so correct syntax would be to use `obj[MyValue.self]`.
+
+* [SE-0310][]:
+  
+  Read-only computed properties and subscripts can now define their `get` accessor to be `async` and/or `throws`, by writing one or both of those keywords between the `get` and `{`.  Thus, these members can now make asynchronous calls or throw errors in the process of producing a value:
+  ```swift
+  class BankAccount: FinancialAccount {
+    var manager: AccountManager?
+
+    var lastTransaction: Transaction {
+      get async throws {
+        guard manager != nil else { throw BankError.notInYourFavor }
+        return await manager!.getLastTransaction()
+      }
+    }
+
+    subscript(_ day: Date) -> [Transaction] {
+      get async {
+        return await manager?.getTransactions(onDay: day) ?? []
+      }
+    }
+  }
+
+  protocol FinancialAccount {
+    associatedtype T
+    var lastTransaction: T { get async throws }
+    subscript(_ day: Date) -> [T] { get async }
+  }
+  ```
+  Accesses to such members, like `lastTransaction` above, will require appropriate marking with `await` and/or `try`:
+  ```swift
+  extension BankAccount {
+    func meetsTransactionLimit(_ limit: Amount) async -> Bool {
+      return try! await self.lastTransaction.amount < limit
+      //                    ^~~~~~~~~~~~~~~~ this access is async & throws
+    }                
+  }
+
+    
+  func hadWithdrawlOn(_ day: Date, from acct: BankAccount) async -> Bool {
+    return await !acct[day].allSatisfy { $0.amount >= Amount.zero }
+    //            ^~~~~~~~~ this access is async
+  }
+  ```
+
+* [SE-0306][]:
+
+  Swift 5.5 includes support for actors, a new kind of type that isolates its instance data to protect it from concurrent access. Accesses to an actor's instance declarations from outside the must be asynchronous:
+
+  ```swift
+  actor Counter {
+    var value = 0
+
+    func increment() {
+      value = value + 1
+    }
+  }
+
+  func useCounter(counter: Counter) async {
+    print(await counter.value) // interaction must be async
+    await counter.increment()  // interaction must be async
+  }
+  ```
+
 * The determination of whether a call to a `rethrows` function can throw now considers default arguments of `Optional` type.
 
   In Swift 5.4, such default arguments were ignored entirely by `rethrows` checking. This meant that the following example was accepted:
@@ -173,11 +230,11 @@ Swift 5.5
 
   The "for" loop can be used to traverse asynchronous sequences in asynchronous code:
 
-	```swift
+  ```swift
   for try await line in myFile.lines() {
     // Do something with each line
   }
-	```
+  ```
 
   Asynchronous for loops use asynchronous sequences, defined by the protocol
   `AsyncSequence` and its corresponding `AsyncIterator`.
@@ -187,6 +244,8 @@ Swift 5.5
 Swift 5.4
 ---------
 
+### 2021-04-26 (Xcode 12.5)
+
 * Protocol conformance checking now considers `where` clauses when evaluating if a `typealias` is a suitable witness for an associated type requirement. The following code is now rejected:
 
   ```swift
@@ -8429,11 +8488,13 @@ Swift 1.0
 [SE-0284]: <https://github.com/apple/swift-evolution/blob/main/proposals/0284-multiple-variadic-parameters.md>
 [SE-0286]: <https://github.com/apple/swift-evolution/blob/main/proposals/0286-forward-scan-trailing-closures.md>
 [SE-0287]: <https://github.com/apple/swift-evolution/blob/main/proposals/0287-implicit-member-chains.md>
+[SE-0293]: <https://github.com/apple/swift-evolution/blob/main/proposals/0293-extend-property-wrappers-to-function-and-closure-parameters.md>
 [SE-0296]: <https://github.com/apple/swift-evolution/blob/main/proposals/0296-async-await.md>
 [SE-0297]: <https://github.com/apple/swift-evolution/blob/main/proposals/0297-concurrency-objc.md>
 [SE-0298]: <https://github.com/apple/swift-evolution/blob/main/proposals/0298-asyncsequence.md>
 [SE-0299]: <https://github.com/apple/swift-evolution/blob/main/proposals/0299-extend-generic-static-member-lookup.md>
-[SE-0293]: <https://github.com/apple/swift-evolution/blob/main/proposals/0293-extend-property-wrappers-to-function-and-closure-parameters.md>
+[SE-0306]: <https://github.com/apple/swift-evolution/blob/main/proposals/0306-actors.md>
+[SE-0310]: <https://github.com/apple/swift-evolution/blob/main/proposals/0310-effectful-readonly-properties.md>
 
 [SR-75]: <https://bugs.swift.org/browse/SR-75>
 [SR-106]: <https://bugs.swift.org/browse/SR-106>

benchmark/cmake/modules/AddSwiftBenchmarkSuite.cmake

@@ -108,7 +108,7 @@ macro(configure_sdks_darwin)
   set(macosx_arch "x86_64" "arm64")
   set(iphoneos_arch "arm64" "arm64e" "armv7")
   set(appletvos_arch "arm64")
-  set(watchos_arch "armv7k")
+  set(watchos_arch "armv7k" "arm64_32")
 
   set(macosx_ver "10.9")
   set(iphoneos_ver "8.0")

cmake/modules/DarwinSDKs.cmake

@@ -12,8 +12,8 @@ endif()
 
 set(SUPPORTED_TVOS_ARCHS "arm64")
 set(SUPPORTED_TVOS_SIMULATOR_ARCHS "x86_64;arm64")
-set(SUPPORTED_WATCHOS_ARCHS "armv7k")
-set(SUPPORTED_WATCHOS_SIMULATOR_ARCHS "i386;arm64")
+set(SUPPORTED_WATCHOS_ARCHS "armv7k;arm64_32")
+set(SUPPORTED_WATCHOS_SIMULATOR_ARCHS "i386;x86_64;arm64")
 set(SUPPORTED_OSX_ARCHS "x86_64;arm64;arm64e")
 
 is_sdk_requested(OSX swift_build_osx)

cmake/modules/Libdispatch.cmake

@@ -101,6 +101,14 @@ foreach(sdk ${DISPATCH_SDKS})
                           # ensure that we strip out the DESTDIR environment
                           # from the sub-build
                           ${CMAKE_COMMAND} -E env --unset=DESTDIR ${CMAKE_COMMAND} --build . --target install
+                        COMMAND
+                          ${CMAKE_COMMAND} -E copy
+                          <INSTALL_DIR>/${LIBDISPATCH_RUNTIME_DIR}/${SWIFT_SDK_${sdk}_SHARED_LIBRARY_PREFIX}dispatch${SWIFT_SDK_${sdk}_SHARED_LIBRARY_SUFFIX}
+                          ${SWIFTLIB_DIR}/${SWIFT_SDK_${sdk}_LIB_SUBDIR}/${arch}/${SWIFT_SDK_${sdk}_SHARED_LIBRARY_PREFIX}dispatch${SWIFT_SDK_${sdk}_SHARED_LIBRARY_SUFFIX}
+                        COMMAND
+                          ${CMAKE_COMMAND} -E copy
+                          <INSTALL_DIR>/${LIBDISPATCH_RUNTIME_DIR}/${SWIFT_SDK_${sdk}_SHARED_LIBRARY_PREFIX}BlocksRuntime${SWIFT_SDK_${sdk}_SHARED_LIBRARY_SUFFIX}
+                          ${SWIFTLIB_DIR}/${SWIFT_SDK_${sdk}_LIB_SUBDIR}/${arch}/${SWIFT_SDK_${sdk}_SHARED_LIBRARY_PREFIX}BlocksRuntime${SWIFT_SDK_${sdk}_SHARED_LIBRARY_SUFFIX}
                         STEP_TARGETS
                           install
                         BUILD_BYPRODUCTS

cmake/modules/SwiftSetIfArchBitness.cmake

@@ -12,6 +12,7 @@ function(set_if_arch_bitness var_name)
      "${SIA_ARCH}" STREQUAL "armv6" OR
      "${SIA_ARCH}" STREQUAL "armv7" OR
      "${SIA_ARCH}" STREQUAL "armv7k" OR
+     "${SIA_ARCH}" STREQUAL "arm64_32" OR
      "${SIA_ARCH}" STREQUAL "armv7s" OR
      "${SIA_ARCH}" STREQUAL "wasm32")
     set("${var_name}" "${SIA_CASE_32_BIT}" PARENT_SCOPE)

docs/ABI/Mangling.rst

@@ -147,7 +147,6 @@ Globals
   // TODO check this::
   global ::= mangled-name 'TA'                     // partial application forwarder
   global ::= mangled-name 'Ta'                     // ObjC partial application forwarder
-  global ::= mangled-name 'Tw' index               // async partial apply thunk for a non-constant function
   global ::= mangled-name 'TQ' index               // Async await continuation partial function
   global ::= mangled-name 'TY' index               // Async suspend continuation partial function
 
@@ -515,13 +514,17 @@ Types
 
   type ::= 'Bb'                              // Builtin.BridgeObject
   type ::= 'BB'                              // Builtin.UnsafeValueBuffer
-  type ::= 'Bc'                              // Builtin.RawUnsafeContinuation
-  type ::= 'BD'                              // Builtin.DefaultActorStorage
-  type ::= 'Be'                              // Builtin.ExecutorRef
+  #if SWIFT_RUNTIME_VERSION >= 5.5
+    type ::= 'Bc'                              // Builtin.RawUnsafeContinuation
+    type ::= 'BD'                              // Builtin.DefaultActorStorage
+    type ::= 'Be'                              // Builtin.Executor
+  #endif
   type ::= 'Bf' NATURAL '_'                  // Builtin.Float<n>
   type ::= 'Bi' NATURAL '_'                  // Builtin.Int<n>
   type ::= 'BI'                              // Builtin.IntLiteral
-  type ::= 'Bj'                              // Builtin.Job
+  #if SWIFT_RUNTIME_VERSION >= 5.5
+    type ::= 'Bj'                              // Builtin.Job
+  #endif
   type ::= 'BO'                              // Builtin.UnknownObject (no longer a distinct type, but still used for AnyObject)
   type ::= 'Bo'                              // Builtin.NativeObject
   type ::= 'Bp'                              // Builtin.RawPointer
@@ -571,19 +574,21 @@ Types
                                              // they are mangled separately as part of the entity.
   params-type ::= empty-list                 // shortcut for no parameters
 
-  sendable ::= 'J'                           // @Sendable on function types
-  async ::= 'Y'                              // 'async' annotation on function types
+  #if SWIFT_RUNTIME_VERSION >= 5.5
+    async ::= 'Ya'                             // 'async' annotation on function types
+    sendable ::= 'Yb'                          // @Sendable on function types
+  #endif
   throws ::= 'K'                             // 'throws' annotation on function types
-  differentiable ::= 'jf'                    // @differentiable(_forward) on function type
-  differentiable ::= 'jr'                    // @differentiable(reverse) on function type
-  differentiable ::= 'jd'                    // @differentiable on function type
-  differentiable ::= 'jl'                    // @differentiable(_linear) on function type
+  differentiable ::= 'Yjf'                   // @differentiable(_forward) on function type
+  differentiable ::= 'Yjr'                   // @differentiable(reverse) on function type
+  differentiable ::= 'Yjd'                   // @differentiable on function type
+  differentiable ::= 'Yjl'                   // @differentiable(_linear) on function type
 
   type-list ::= list-type '_' list-type*     // list of types
   type-list ::= empty-list
 
                                                   // FIXME: Consider replacing 'h' with a two-char code
-  list-type ::= type identifier? 'z'? 'h'? 'n'? 'd'?   // type with optional label, inout convention, shared convention, owned convention, and variadic specifier
+  list-type ::= type identifier? 'Yk'? 'z'? 'h'? 'n'? 'd'?  // type with optional label, '@noDerivative', inout convention, shared convention, owned convention, and variadic specifier
 
   METATYPE-REPR ::= 't'                      // Thin metatype representation
   METATYPE-REPR ::= 'T'                      // Thick metatype representation
@@ -667,8 +672,10 @@ mangled in to disambiguate.
   COROUTINE-KIND ::= 'A'                     // yield-once coroutine
   COROUTINE-KIND ::= 'G'                     // yield-many coroutine
 
-  SENDABLE ::= 'h'                         // @Sendable
-  ASYNC ::= 'H'                              // @async
+  #if SWIFT_RUNTIME_VERSION >= 5.5
+    SENDABLE ::= 'h'                           // @Sendable
+    ASYNC ::= 'H'                              // @async
+  #endif
 
   PARAM-CONVENTION ::= 'i'                   // indirect in
   PARAM-CONVENTION ::= 'c'                   // indirect in constant