Merge branch 'master' into add-equatable-conformance

Author: tkachukandrew

.gitignore

@@ -22,6 +22,7 @@
 #==============================================================================#
 # Explicit files to ignore (only matches one).
 #==============================================================================#
+Brewfile.lock.json
 cscope.files
 cscope.out
 .vimrc

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 +24,92 @@ CHANGELOG
 
 </details>
 
-Swift Next
+Swift 5.3
 ----------
 
+* [SE-0268][]:
+  
+  A `didSet` observer which does not refer to the `oldValue` in its body or does not explicitly request it by placing it in the parameter list (i.e. `didSet(oldValue)`) will no longer trigger a call to the property getter to fetch the `oldValue`.
+  
+  ```swift
+  class C {
+    var value: Int = 0 {
+      didSet { print("didSet called!") }
+    }
+  }
+  
+  let c = C()
+  // This does not trigger a call to the getter for 'value'
+  // because the 'didSet' observer on 'value' does not
+  // refer to the 'oldValue' in its body, which means
+  // the 'oldValue' does not need to be fetched.
+  c.value = 1
+  ```
+  
+* [SE-0276][]:
+
+  Catch clauses in a `do`-`catch` statement can now include multiple patterns in a comma-separated list. The body of a `catch` clause will be executed if a thrown error matches any of its patterns.
+
+  ```swift
+  do {
+    try performTask()
+  } catch TaskError.someFailure(let msg),
+          TaskError.anotherFailure(let msg) {
+    showMessage(msg)
+  }
+  ```
+
+* [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).
@@ -62,9 +146,13 @@ Swift Next
   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
@@ -257,8 +345,6 @@ Swift 5.2
   print(s[0])
   ```
 
-**Add new entries to the top of this section, not here!**
-
 Swift 5.1
 ---------
 
@@ -7914,8 +8000,13 @@ Swift 1.0
 [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-0268]: <https://github.com/apple/swift-evolution/blob/master/proposals/0268-didset-semantics.md>
 [SE-0269]: <https://github.com/apple/swift-evolution/blob/master/proposals/0269-implicit-self-explicit-capture.md>
+[SE-0276]: <https://github.com/apple/swift-evolution/blob/master/proposals/0276-multi-pattern-catch-clauses.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>

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.4.3)
+cmake_minimum_required(VERSION 3.12.4)
 
 # TODO: Fix RPATH usage to be CMP0068 compliant
 # Disable Policy CMP0068 for CMake 3.9
@@ -137,7 +137,7 @@ set(SWIFT_ANALYZE_CODE_COVERAGE FALSE CACHE STRING
 # SWIFT_VERSION is deliberately /not/ cached so that an existing build directory
 # can be reused when a new version of Swift comes out (assuming the user hasn't
 # manually set it as part of their own CMake configuration).
-set(SWIFT_VERSION "5.2")
+set(SWIFT_VERSION "5.3")
 
 set(SWIFT_VENDOR "" CACHE STRING
     "The vendor name of the Swift compiler")
@@ -477,7 +477,6 @@ endif()
 include(SwiftComponents)
 include(SwiftHandleGybSources)
 include(SwiftSetIfArchBitness)
-include(SwiftSource)
 include(AddSwift)
 include(SwiftConfigureSDK)
 include(SwiftComponents)
@@ -571,6 +570,8 @@ else()
     set(SWIFT_HOST_VARIANT_SDK_default "LINUX")
   elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "FreeBSD")
     set(SWIFT_HOST_VARIANT_SDK_default "FREEBSD")
+  elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "OpenBSD")
+    set(SWIFT_HOST_VARIANT_SDK_default "OPENBSD")
   elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "CYGWIN")
     set(SWIFT_HOST_VARIANT_SDK_default "CYGWIN")
   elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
@@ -674,6 +675,15 @@ elseif("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "FREEBSD")
   set(SWIFT_PRIMARY_VARIANT_SDK_default  "${SWIFT_HOST_VARIANT_SDK}")
   set(SWIFT_PRIMARY_VARIANT_ARCH_default "${SWIFT_HOST_VARIANT_ARCH}")
 
+elseif("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "OPENBSD")
+
+  set(SWIFT_HOST_VARIANT "openbsd" CACHE STRING
+      "Deployment OS for Swift host tools (the compiler) [openbsd].")
+
+  configure_sdk_unix("OpenBSD" "${SWIFT_HOST_VARIANT_ARCH}")
+  set(SWIFT_PRIMARY_VARIANT_SDK_default  "${SWIFT_HOST_VARIANT_SDK}")
+  set(SWIFT_PRIMARY_VARIANT_ARCH_default "${SWIFT_HOST_VARIANT_ARCH}")
+
 elseif("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "CYGWIN")
 
   set(SWIFT_HOST_VARIANT "cygwin" CACHE STRING
@@ -882,7 +892,14 @@ if(NOT CMAKE_SYSTEM_NAME STREQUAL "Darwin")
   endif()
 endif()
 
-find_package(PythonInterp REQUIRED)
+find_package(Python2 COMPONENTS Interpreter REQUIRED)
+find_package(Python3 COMPONENTS Interpreter)
+if(NOT Python3_Interpreter_FOUND)
+  message(WARNING "Python3 not found, using python2 as a fallback")
+  add_executable(Python3::Interpreter IMPORTED)
+  set_target_properties(Python3::Interpreter PROPERTIES
+    IMPORTED_LOCATION ${Python2_EXECUTABLE})
+endif()
 
 #
 # Find optional dependencies.
@@ -1028,11 +1045,13 @@ if(SWIFT_BUILD_SYNTAXPARSERLIB OR SWIFT_BUILD_SOURCEKIT)
       set(SOURCEKIT_RUNTIME_DIR lib)
     endif()
     add_dependencies(sourcekit-inproc BlocksRuntime dispatch)
-    swift_install_in_component(FILES
-                                 $<TARGET_FILE:dispatch>
-                                 $<TARGET_FILE:BlocksRuntime>
-                               DESTINATION ${SOURCEKIT_RUNTIME_DIR}
-                               COMPONENT sourcekit-inproc)
+    if("${SWIFT_HOST_VARIANT_SDK}" MATCHES "OSX|WINDOWS")
+      swift_install_in_component(FILES
+                                   $<TARGET_FILE:dispatch>
+                                   $<TARGET_FILE:BlocksRuntime>
+                                 DESTINATION ${SOURCEKIT_RUNTIME_DIR}
+                                 COMPONENT sourcekit-inproc)
+    endif()
     if(SWIFT_HOST_VARIANT_SDK STREQUAL WINDOWS)
       swift_install_in_component(FILES
                                    $<TARGET_LINKER_FILE:dispatch>

README.md

@@ -19,7 +19,7 @@
 |**[Android](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04_LTS_android.json)** | ARMv7 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android)|
 |**[Android](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04_LTS_android.json)** | AArch64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android-arm64/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android-arm64)|
 |**[Windows 2019 (VS 2017)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_windows_2019.json)** | x86_64 | [![Build Status](https://ci-external.swift.org/job/oss-swift-windows-x86_64/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-windows-x86_64)|
-|**[Windows 2019 (VS 2019)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_windows_2019_VS2019.json)** | x86_64 | [![Build Status](https://ci-external.swift.org/job/oss-swift-windows-x86_64-vs2019/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/ooss-swift-windows-x86_64-vs2019)|
+|**[Windows 2019 (VS 2019)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_windows_2019_VS2019.json)** | x86_64 | [![Build Status](https://ci-external.swift.org/job/oss-swift-windows-x86_64-vs2019/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-windows-x86_64-vs2019)|
 
 **Swift TensorFlow Community-Hosted CI Platforms**
 
@@ -78,6 +78,9 @@ source code and up to 70 GB of disk space for the build artifacts with full
 debugging. Depending on your machine, a clean build can take a few minutes to
 several hours. Naturally, incremental builds are much faster.
 
+Once you are able to build things successfully and have a compile-test-debug
+loop going, check out the [development tips](docs/DevelopmentTips.md) for
+better productivity while working on the compiler.
 
 ### System Requirements
 
@@ -88,7 +91,7 @@ Please make sure you use Python 2.x. Python 3.x is not supported currently.
 
 #### macOS
 
-To build for macOS, you need [Xcode 11.3](https://developer.apple.com/xcode/downloads/).
+To build for macOS, you need [Xcode 11.4](https://developer.apple.com/xcode/resources/).
 The required version of Xcode changes frequently, and is often a beta release.
 Check this document or the host information on <https://ci.swift.org> for the
 current required version.
@@ -99,6 +102,12 @@ which can be installed via a package manager:
 **[Homebrew](https://brew.sh/)**
 
     brew install cmake ninja
+    
+You can also use [homebrew-bundle](https://github.com/Homebrew/homebrew-bundle)
+from the root of this repository's working directory to install all of these
+dependencies:
+
+    brew bundle
 
 **[MacPorts](https://macports.org)**
 
@@ -110,9 +119,29 @@ Instructions for installing CMake and Ninja directly can be found [below](#build
 
 For Ubuntu, you'll need the following development dependencies:
 
-    sudo apt-get install git cmake ninja-build clang python uuid-dev libicu-dev icu-devtools libedit-dev \
-        libxml2-dev libsqlite3-dev swig libpython-dev libncurses5-dev pkg-config libcurl4-openssl-dev \
-        systemtap-sdt-dev tzdata rsync python-six
+```
+sudo apt-get install    \
+  clang                 \
+  cmake                 \
+  git                   \
+  icu-devtools          \
+  libcurl4-openssl-dev  \
+  libedit-dev           \
+  libicu-dev            \
+  libncurses5-dev       \
+  libpython-dev         \
+  libsqlite3-dev        \
+  libxml2-dev           \
+  ninja-build           \
+  pkg-config            \
+  python                \
+  python-six            \
+  rsync                 \
+  swig                  \
+  systemtap-sdt-dev     \
+  tzdata                \
+  uuid-dev
+```
 
 **Note:** LLDB currently requires at least `swig-1.3.40` but will successfully build
 with version 2 shipped with Ubuntu.
@@ -129,7 +158,9 @@ First create a directory for all of the Swift sources:
 **Note:** This is important since update-checkout (see below) checks out
 repositories next to the Swift source directory. This means that if one clones
 Swift and has other unrelated repositories, update-checkout may not clone those
-repositories and will update them instead.
+repositories and will update them instead. Be aware that `update-checkout`
+currently does not support paths with non-ASCII characters. If such characters
+are present in the path to `swift-source`, `update-checkout` will fail.
 
 **Via HTTPS**  For those checking out sources as read-only, HTTPS works best:
 
@@ -336,7 +367,7 @@ expressed today.
 
 ### CMake
 [CMake](https://cmake.org) is the core infrastructure used to configure builds of
-Swift and its companion projects; at least version 3.4.3 is required.
+Swift and its companion projects; at least version 3.16.5 is required.
 
 On macOS, you can download the [CMake Binary Distribution](https://cmake.org/download),
 bundled as an application, copy it to `/Applications`, and add the embedded

benchmark/CMakeLists.txt

@@ -62,6 +62,7 @@ set(SWIFT_BENCH_MODULES
     single-source/Combos
     single-source/DataBenchmarks
     single-source/DeadArray
+    single-source/DevirtualizeProtocolComposition
     single-source/DictOfArraysToArrayOfDicts
     single-source/DictTest
     single-source/DictTest2
@@ -95,8 +96,7 @@ set(SWIFT_BENCH_MODULES
     single-source/Hanoi
     single-source/Hash
     single-source/Histogram
-    single-source/InsertCharacter  
-    single-source/IntegerParsing
+    single-source/HTTP2StateMachine
     single-source/Integrate
     single-source/IterateData
     single-source/Join
@@ -140,6 +140,7 @@ set(SWIFT_BENCH_MODULES
     single-source/RGBHistogram
     single-source/Radix2CooleyTukey
     single-source/RandomShuffle
+    single-source/RandomTree
     single-source/RandomValues
     single-source/RangeAssignment
     single-source/RangeIteration
@@ -225,6 +226,9 @@ endif()
 set(SWIFT_BENCHMARK_EXTRA_FLAGS "" CACHE STRING
     "Extra options to pass to swiftc when building the benchmarks")
 
+set(SWIFT_BENCHMARK_UNOPTIMIZED_DRIVER NO CACHE BOOL
+    "Build the benchmark driver utilites without optimization (default: no)")
+
 if (SWIFT_BENCHMARK_BUILT_STANDALONE)
   # This option's value must match the value of the same option used when
   # building the swift runtime.

benchmark/Package.swift

@@ -22,19 +22,19 @@ func getSingleSourceLibraries(subDirectory: String) -> [String] {
   let fileURLs = try! f.contentsOfDirectory(at: dirURL,
                                             includingPropertiesForKeys: nil)
   return fileURLs.compactMap { (path: URL) -> String? in
-    let c = path.lastPathComponent.split(separator: ".")
-    // Too many components. Must be a gyb file.
-    if c.count > 2 {
-      return nil
-    }
-    if c[1] != "swift" {
+    guard let lastDot = path.lastPathComponent.lastIndex(of: ".") else {
       return nil
     }
+    let ext = String(path.lastPathComponent.suffix(from: lastDot))
+    guard ext == ".swift" else { return nil }
+
+    let name = String(path.lastPathComponent.prefix(upTo: lastDot))
 
-    let name = String(c[0])
+    // Test names must have a single component.
+    if name.contains(".") { return nil }
 
-    // We do not support this test.
     if unsupportedTests.contains(name) {
+      // We do not support this test.
       return nil
     }