---

yaml
---
r: 343471
b: refs/heads/master-rebranch
c: 9c9f0bd
h: refs/heads/master
i:
  343469: e731b95
  343467: 6cec2fd
  343463: f15bcaa
  343455: b41ef6c

Author: compnerd

[refs]

@@ -1455,7 +1455,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-02-a: ddd2b2976aa9bfde5f20fe37f6bd2
 refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-03-a: 171cc166f2abeb5ca2a4003700a8a78a108bd300
 refs/heads/benlangmuir-patch-1: baaebaf39d52f3bf36710d4fe40cf212e996b212
 refs/heads/i-do-redeclare: 8c4e6d5de5c1e3f0a2cedccf319df713ea22c48e
-refs/heads/master-rebranch: f5355d19ca134e3d5bd4b5ec96e80c05175757a3
+refs/heads/master-rebranch: 9c9f0bd440ae618d2212e5a00ef6f34d8e46f20f
 refs/heads/rdar-53901732: 9bd06af3284e18a109cdbf9aa59d833b24eeca7b
 refs/heads/revert-26776-subst-always-returns-a-type: 1b8e18fdd391903a348970a4c848995d4cdd789c
 refs/heads/tensorflow-merge: 8b854f62f80d4476cb383d43c4aac2001dde3cec

branches/master-rebranch/CHANGELOG.md

@@ -26,6 +26,29 @@ CHANGELOG
 Swift Next
 ----------
 
+* [SE-0253][]:
+
+  Values of types that declare `func callAsFunction` methods can be called
+  like functions. The call syntax is shorthand for applying
+  `func callAsFunction` methods.
+
+  ```swift
+  struct Adder {
+    var base: Int
+    func callAsFunction(_ x: Int) -> Int {
+      return x + base
+    }
+  }
+  var adder = Adder(base: 3)
+  adder(10) // returns 13, same as `adder.callAsFunction(10)`
+  ```
+
+  * `func callAsFunction` argument labels are required at call sites.
+  * Multiple `func callAsFunction` methods on a single type are supported.
+  * `mutating func callAsFunction` is supported.
+  * `func callAsFunction` works with `throws` and `rethrows`.
+  * `func callAsFunction` works with trailing closures.
+
 * [SR-4206][]:
 
   A method override is no longer allowed to have a generic signature with 
@@ -7711,6 +7734,7 @@ Swift 1.0
 [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-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>
 
 [SR-106]: <https://bugs.swift.org/browse/SR-106>

branches/master-rebranch/benchmark/CMakeLists.txt

@@ -87,6 +87,7 @@ set(SWIFT_BENCH_MODULES
     single-source/Exclusivity
     single-source/ExistentialPerformance
     single-source/Fibonacci
+    single-source/FindStringNaive
     single-source/FlattenList
     single-source/FloatingPointParsing
     single-source/FloatingPointPrinting

branches/master-rebranch/benchmark/single-source/FindStringNaive.swift

@@ -0,0 +1,185 @@
+//===--- FindStringNaive.swift --------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2019 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import TestsUtils
+
+// Mini benchmark implementing a naive String search algorithm that
+// at the moment shows a lot of ARC traffic.
+let t: [BenchmarkCategory] = [.String, .refcount]
+let N = 100
+
+var longStringFoFoFoFox: String?
+var longArrayFoFoFoFox: [UInt8]?
+
+public let FindStringNaive = [
+  BenchmarkInfo(
+    name: "FindString.Loop1.Substring",
+    runFunction: runBenchLoop1Substring,
+    tags: t,
+    setUpFunction: {
+      longStringFoFoFoFox = String(repeating: "fo", count: 5_000) + "fox <-- needle"
+    }),
+  BenchmarkInfo(
+    name: "FindString.Rec3.String",
+    runFunction: runBenchRecursive3String,
+    tags: t,
+    setUpFunction: {
+      longStringFoFoFoFox = String(repeating: "fo", count: 500) + "fox <-- needle"
+    }),
+  BenchmarkInfo(
+    name: "FindString.Rec3.Substring",
+    runFunction: runBenchRecursive3Substring,
+    tags: t,
+    setUpFunction: {
+      longStringFoFoFoFox = String(repeating: "fo", count: 500) + "fox <-- needle"
+    }),
+  BenchmarkInfo(
+    name: "FindString.Loop1.Array",
+    runFunction: runBenchLoop1Array,
+    tags: t,
+    setUpFunction: {
+      longArrayFoFoFoFox = []
+      longArrayFoFoFoFox!.reserveCapacity(1_100_000)
+      for _ in 0 ..< 500_000 {
+        longArrayFoFoFoFox!.append(contentsOf: "fo".utf8)
+      }
+      longArrayFoFoFoFox!.append(contentsOf: "fox <-- needle".utf8)
+    }),
+  BenchmarkInfo(
+    name: "FindString.Rec3.Array",
+    runFunction: runBenchRecursive3ArrayOfUTF8,
+    tags: t,
+    setUpFunction: {
+      longArrayFoFoFoFox = []
+      longArrayFoFoFoFox!.reserveCapacity(11_000)
+      for _ in 0 ..< 5_000 {
+        longArrayFoFoFoFox!.append(contentsOf: "fo".utf8)
+      }
+      longArrayFoFoFoFox!.append(contentsOf: "fox <-- needle".utf8)
+    }),
+]
+
+func findOne<S: StringProtocol>(
+  _ string: S,
+  needle: Character
+) -> String.Index? {
+  var index = string.startIndex
+  while index < string.endIndex {
+    let nextIndex = string.index(after: index)
+    if string[index] == needle {
+      return index
+    }
+    index = nextIndex
+  }
+  return nil
+}
+
+func findThreeRecursive<S: StringProtocol>(
+  _ string: S,
+  needle1: Character,
+  needle2: Character?,
+  needle3: Character?
+) -> String.Index? {
+  var index = string.startIndex
+  while index < string.endIndex {
+    let nextIndex = string.index(after: index)
+    if string[index] == needle1 {
+      // Check subsequent needles recursively (if applicable)
+      guard let needle2 = needle2 else { return index }
+
+      if findThreeRecursive(
+        string[nextIndex...].prefix(2), needle1: needle2, needle2: needle3, needle3: nil
+      ) == nextIndex {
+        return index
+      }
+    }
+    index = nextIndex
+  }
+  return nil
+}
+
+func findOneOnUTF8Collection<Bytes: Collection>(
+  _ string: Bytes,
+  needle: UInt8
+) -> Bytes.Index? where Bytes.Element == UInt8 {
+  var index = string.startIndex
+  while index < string.endIndex {
+    let nextIndex = string.index(after: index)
+    if string[index] == needle {
+      return index
+    }
+    index = nextIndex
+  }
+  return nil
+}
+
+func findThreeOnUTF8Collection<Bytes: Collection>(
+  _ string: Bytes,
+  needle1: UInt8,
+  needle2: UInt8?,
+  needle3: UInt8?
+) -> Bytes.Index? where Bytes.Element == UInt8 {
+  var index = string.startIndex
+  while index < string.endIndex {
+    let nextIndex = string.index(after: index)
+    if string[index] == needle1 {
+      // Check subsequent needles recursively (if applicable)
+      guard let needle2 = needle2 else { return index }
+
+      if findThreeOnUTF8Collection(
+        string[nextIndex...].prefix(2), needle1: needle2, needle2: needle3, needle3: nil
+      ) == nextIndex {
+        return index
+      }
+    }
+    index = nextIndex
+  }
+  return nil
+}
+
+@inline(never)
+func runBenchLoop1Substring(iterations: Int) {
+  for _ in 0 ..< iterations {
+    precondition(findOne(longStringFoFoFoFox![...], needle: "x") != nil)
+  }
+}
+
+@inline(never)
+func runBenchLoop1Array(iterations: Int) {
+  for _ in 0 ..< iterations {
+    precondition(findOneOnUTF8Collection(longArrayFoFoFoFox!, needle: UInt8(ascii: "x")) != nil)
+  }
+}
+
+@inline(never)
+func runBenchRecursive3Substring(iterations: Int) {
+  for _ in 0 ..< iterations {
+    precondition(findThreeRecursive(longStringFoFoFoFox![...], needle1: "f", needle2: "o", needle3: "x") != nil)
+  }
+}
+
+@inline(never)
+func runBenchRecursive3String(iterations: Int) {
+  for _ in 0 ..< iterations {
+    precondition(findThreeRecursive(longStringFoFoFoFox!, needle1: "f", needle2: "o", needle3: "x") != nil)
+  }
+}
+
+@inline(never)
+func runBenchRecursive3ArrayOfUTF8(iterations: Int) {
+  for _ in 0 ..< iterations {
+    precondition(findThreeOnUTF8Collection(longArrayFoFoFoFox!,
+                                      needle1: UInt8(ascii: "f"),
+                                      needle2: UInt8(ascii: "o"),
+                                      needle3: UInt8(ascii: "x")) != nil)
+  }
+}

branches/master-rebranch/benchmark/utils/main.swift

@@ -75,6 +75,7 @@ import ErrorHandling
 import Exclusivity
 import ExistentialPerformance
 import Fibonacci
+import FindStringNaive
 import FlattenList
 import FloatingPointParsing
 import FloatingPointPrinting
@@ -253,6 +254,7 @@ registerBenchmark(ErrorHandling)
 registerBenchmark(Exclusivity)
 registerBenchmark(ExistentialPerformance)
 registerBenchmark(Fibonacci)
+registerBenchmark(FindStringNaive)
 registerBenchmark(FlattenListLoop)
 registerBenchmark(FlattenListFlatMap)
 registerBenchmark(FloatingPointParsing)

branches/master-rebranch/cmake/modules/AddSwift.cmake

@@ -2370,7 +2370,7 @@ function(_add_swift_executable_single name)
   # NOTE(compnerd) use the C linker language to invoke `clang` rather than
   # `clang++` as we explicitly link against the C++ runtime.  We were previously
   # actually passing `-nostdlib++` to avoid the C++ runtime linkage.
-  if(SWIFTEXE_SINGLE_SDK STREQUAL ANDROID)
+  if(${SWIFTEXE_SINGLE_SDK} STREQUAL ANDROID)
     set_property(TARGET "${name}" PROPERTY
       LINKER_LANGUAGE "C")
   else()