Merge branch 'master' into foundation-no-inlinable-shim-calls

Author: lorentey

.flake8

@@ -1,32 +1,72 @@
 [flake8]
-ignore = W291 W504
-filename = *.py,
-           ./utils/80+-check,
-           ./utils/backtrace-check,
-           ./benchmark/scripts/Benchmark_Driver,
-           ./benchmark/scripts/Benchmark_DTrace.in,
-           ./benchmark/scripts/Benchmark_GuardMalloc.in,
-           ./benchmark/scripts/Benchmark_RuntimeLeaksRunner.in,
-           ./utils/build-script,
-           ./utils/check-incremental,
-           ./test/Driver/Inputs/fake-toolchain/clang++,
-           ./utils/coverage/coverage-build-db,
-           ./utils/coverage/coverage-generate-data,
-           ./utils/coverage/coverage-query-db,
-           ./utils/coverage/coverage-touch-tests,
-           ./utils/gyb,
-           ./test/Driver/Inputs/fake-toolchain/ld,
-           ./utils/line-directive,
-           ./utils/swift_build_support/tests/mock-distcc,
-           ./docs/scripts/ns-html2rst,
-           ./utils/PathSanitizingFileCheck,
-           ./utils/recursive-lipo,
-           ./utils/round-trip-syntax-test,
-           ./utils/rth,
-           ./utils/run-remote,
-           ./utils/run-test,
-           ./utils/scale-test,
-           ./utils/submit-benchmark-results,
-           ./utils/update-checkout,
-           ./utils/viewcfg,
-           ./utils/symbolicate-linux-fatal,
+
+filename =
+    *.py,
+
+    ./benchmark/scripts/Benchmark_Driver,
+    ./benchmark/scripts/Benchmark_DTrace.in,
+    ./benchmark/scripts/Benchmark_GuardMalloc.in,
+    ./benchmark/scripts/Benchmark_QuickCheck.in,
+    ./benchmark/scripts/Benchmark_RuntimeLeaksRunner.in,
+    ./benchmark/scripts/run_smoke_bench,
+
+    ./docs/scripts/ns-html2rst,
+
+    ./test/Driver/Inputs/fake-toolchain/ld,
+
+    ./utils/80+-check,
+    ./utils/backtrace-check,
+    ./utils/build-parser-lib,
+    ./utils/build-script,
+    ./utils/check-incremental,
+    ./utils/coverage/coverage-build-db,
+    ./utils/coverage/coverage-generate-data,
+    ./utils/coverage/coverage-query-db,
+    ./utils/coverage/coverage-touch-tests,
+    ./utils/dev-scripts/blockifyasm,
+    ./utils/dev-scripts/split-cmdline,
+    ./utils/gyb,
+    ./utils/line-directive,
+    ./utils/PathSanitizingFileCheck,
+    ./utils/recursive-lipo,
+    ./utils/round-trip-syntax-test,
+    ./utils/rth,
+    ./utils/run-test,
+    ./utils/scale-test,
+    ./utils/submit-benchmark-results,
+    ./utils/swift_build_support/tests/mock-distcc,
+    ./utils/symbolicate-linux-fatal,
+    ./utils/update-checkout,
+    ./utils/viewcfg,
+
+    # TODO: We should be linting the lit configs.
+    #lit.cfg,
+
+exclude =
+    .git,
+    __pycache__,
+
+ignore =
+    # The black tool treats slices consistently, the E203 warning is not PEP8
+    # compliant (https://github.com/psf/black#slices).
+    E203,
+
+    # FIXME: We should not have trailing whitespace.
+    W291,
+
+    # Line breaks before binary operators are not explicitly disallowed in
+    # PEP8, rather it should be consistent throughout the project. The black
+    # tool puts them on new lines which is to be considered a best practice
+    # in the future.
+    W503,
+
+    # Similarly ignore line break after binary operators.
+    W504,
+
+    # TODO: Ignore Bugbear lints for now, but we should enable these in the
+    # future.
+    B,
+
+# 10% larger than the standard 80 character limit. Conforms to the black
+# standard and Bugbear's B950.
+max-line-length = 88

.gitignore

@@ -22,6 +22,7 @@
 #==============================================================================#
 # Explicit files to ignore (only matches one).
 #==============================================================================#
+Brewfile.lock.json
 cscope.files
 cscope.out
 .vimrc
@@ -39,6 +40,9 @@ docs/_build
 # Visual Studio metadata
 .vs
 
+# clangd
+.clangd
+
 #==============================================================================#
 # Ignore CMake temporary files
 #==============================================================================#

Brewfile

@@ -0,0 +1,2 @@
+brew "cmake"
+brew "ninja"

CHANGELOG.md

@@ -6,7 +6,8 @@ CHANGELOG
 
 | Version                | Released   | Toolchain   |
 | :--------------------- | :--------- | :---------- |
-| [Swift 5.2](#swift-52) |            |             |
+| [Swift 5.3](#swift-53) |            |             |
+| [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  |
@@ -23,9 +24,103 @@ CHANGELOG
 
 </details>
 
+Swift 5.3
+----------
+
+* [SE-0280][]:
+  
+  Enum cases can now satisfy static protocol requirements. A static get-only property of type `Self` can be witnessed by an enum case with no associated values and a static function with arguments and returning `Self` can be witnessed by an enum case with associated values.
+  
+  ```swift
+  protocol P {
+    static var foo: Self { get }
+    static func bar(value: Int) -> Self
+  }
+  
+  enum E: P {
+    case foo // matches 'static var foo'
+    case bar(value: Int) // matches 'static func bar(value:)'
+  }
+  ```
+
+* [SE-0267][]:
+  
+  Non-generic members that support a generic parameter list, including nested type declarations, are now allowed to carry a contextual `where` clause against outer generic parameters. Previously, such declarations could only be expressed by placing the member inside a dedicated constrained extension.
+
+  ```swift
+  struct Box<Wrapped> {
+    func boxes() -> [Box<Wrapped.Element>] where Wrapped: Sequence { ... }
+  }
+  ```
+  Since contextual `where` clauses are effectively visibility constraints, overrides adopting this feature must be at least as visible as the overridden method. In practice, this implies any instance of `Derived` that can access `Base.foo` must also be able to access `Derived.foo`.
+  
+  ```swift
+  class Base<T> {
+    func foo() where T == Int { ... }
+  }
+  
+  class Derived<U>: Base<U> {
+    // OK, <U where U: Equatable> has broader visibility than <T where T == Int>
+    override func foo() where U: Equatable { ... } 
+  }
+
+* [SR-75][]:
+
+  Unapplied references to protocol methods are now supported. Previously this
+  only worked for methods defined in structs, enums and classes.
+
+  ```swift
+  protocol Cat {
+    func play(catToy: Toy)
+  }
+
+  let fn = Cat.play(catToy:)
+  fn(myCat)(myToy)
+  ```
+
+* [SE-0266][]:
+  
+  Enumerations with no associated values, or only `Comparable` associated values, can opt-in to synthesized `Comparable` conformance by declaring conformance to the `Comparable` protocol. The synthesized implementation orders the cases first by case-declaration order, and then by lexicographic order of the associated values (if any).
+  
+  ```swift
+  enum Foo: Comparable {
+    case a(Int), b(Int), c
+  }
+  
+  // .a(0) < .a(1) < .b(0) < .b(1) < .c
+  ```
+
+* [SE-0269][]:
+
+  When an escaping closure explicitly captures `self` in its capture list, the
+  use of implicit `self` is enabled within that closure. This means that the
+  following code is now valid:
+  
+  ```swift
+  func doStuff(_ stuff: @escaping () -> Void) {}
+  
+  class C {
+    var x = 0
+
+    func method() {
+      doStuff { [self] in
+        x += 1
+      }
+    }
+  }
+  ```
+  
+  This proposal also introduces new diagnostics for inserting `self` into the
+  closure's capture list in addition to the existing 'use `self.` explicitly'
+  fix-it.
+
+**Add new entries to the top of this section, not here!**
+
 Swift 5.2
 ---------
 
+### 2020-03-24 (Xcode 11.4)
+
 * [SR-11841][]:
 
   When chaining calls to `filter(_:)` on a lazy sequence or collection, the
@@ -166,13 +261,30 @@ Swift 5.2
   * `mutating func callAsFunction` is supported.
   * `func callAsFunction` works with `throws` and `rethrows`.
   * `func callAsFunction` works with trailing closures.
+  
+* [SE-0249][]:
+
+  A `\Root.value` key path expression is now allowed wherever a `(Root) -> Value` 
+  function is allowed. Such an expression is implicitly converted to a key path 
+  application of `{ $0[keyPath: \Root.value] }`.
+  
+  For example:
+  
+  ```swift
+  struct User {
+    let email: String
+    let isAdmin: Bool
+  }
+  
+  users.map(\.email) // this is equivalent to: users.map { $0[keyPath: \User.email] }
+  ```
 
 * [SR-4206][]:
 
   A method override is no longer allowed to have a generic signature with
   requirements not imposed by the base method. For example:
 
-  ```
+  ```swift
   protocol P {}
 
   class Base {
@@ -201,8 +313,6 @@ Swift 5.2
   print(s[0])
   ```
 
-**Add new entries to the top of this section, not here!**
-
 Swift 5.1
 ---------
 
@@ -7853,10 +7963,16 @@ Swift 1.0
 [SE-0242]: <https://github.com/apple/swift-evolution/blob/master/proposals/0242-default-values-memberwise.md>
 [SE-0244]: <https://github.com/apple/swift-evolution/blob/master/proposals/0244-opaque-result-types.md>
 [SE-0245]: <https://github.com/apple/swift-evolution/blob/master/proposals/0245-array-uninitialized-initializer.md>
+[SE-0249]: <https://github.com/apple/swift-evolution/blob/master/proposals/0249-key-path-literal-function-expressions.md>
 [SE-0252]: <https://github.com/apple/swift-evolution/blob/master/proposals/0252-keypath-dynamic-member-lookup.md>
 [SE-0253]: <https://github.com/apple/swift-evolution/blob/master/proposals/0253-callable.md>
 [SE-0254]: <https://github.com/apple/swift-evolution/blob/master/proposals/0254-static-subscripts.md>
+[SE-0266]: <https://github.com/apple/swift-evolution/blob/master/proposals/0266-synthesized-comparable-for-enumerations.md>
+[SE-0267]: <https://github.com/apple/swift-evolution/blob/master/proposals/0267-where-on-contextually-generic.md>
+[SE-0269]: <https://github.com/apple/swift-evolution/blob/master/proposals/0269-implicit-self-explicit-capture.md>
+[SE-0280]: <https://github.com/apple/swift-evolution/blob/master/proposals/0280-enum-cases-as-protocol-witnesses.md>
 
+[SR-75]: <https://bugs.swift.org/browse/SR-75>
 [SR-106]: <https://bugs.swift.org/browse/SR-106>
 [SR-419]: <https://bugs.swift.org/browse/SR-419>
 [SR-631]: <https://bugs.swift.org/browse/SR-631>