[SE-0134][stdlib] Rename/remove two properties on String

stdlib/private/SwiftPrivate/IO.swift

@@ -100,14 +100,14 @@ public struct _FDOutputStream : TextOutputStream {
   }
 
   public mutating func write(_ string: String) {
-    let utf8 = string.nulTerminatedUTF8
-    utf8.withUnsafeBufferPointer {
-      (utf8) -> Void in
+    let utf8CStr = string.utf8CString
+    utf8CStr.withUnsafeBufferPointer {
+      (utf8CStr) -> Void in
       var writtenBytes = 0
-      let bufferSize = utf8.count - 1
+      let bufferSize = utf8CStr.count - 1
       while writtenBytes != bufferSize {
         let result = _swift_stdlib_write(
-          self.fd, UnsafePointer(utf8.baseAddress! + Int(writtenBytes)),
+          self.fd, UnsafeRawPointer(utf8CStr.baseAddress! + Int(writtenBytes)),
           bufferSize - writtenBytes)
         if result < 0 {
           fatalError("write() returned an error")

stdlib/private/SwiftPrivateLibcExtras/SwiftPrivateLibcExtras.swift

@@ -22,11 +22,11 @@ public func _stdlib_mkstemps(_ template: inout String, _ suffixlen: CInt) -> CIn
 #if os(Android)
   preconditionFailure("mkstemps doesn't work on Android")
 #else
-  var utf8 = template.nulTerminatedUTF8
-  let (fd, fileName) = utf8.withUnsafeMutableBufferPointer {
-    (utf8) -> (CInt, String) in
-    let fd = mkstemps(UnsafeMutablePointer(utf8.baseAddress!), suffixlen)
-    let fileName = String(cString: utf8.baseAddress!)
+  var utf8CStr = template.utf8CString
+  let (fd, fileName) = utf8CStr.withUnsafeMutableBufferPointer {
+    (utf8CStr) -> (CInt, String) in
+    let fd = mkstemps(utf8CStr.baseAddress!, suffixlen)
+    let fileName = String(cString: utf8CStr.baseAddress!)
     return (fd, fileName)
   }
   template = fileName

stdlib/public/core/LifetimeManager.swift

@@ -43,8 +43,8 @@ extension String {
   public func withCString<Result>(
     _ body: @noescape (UnsafePointer<Int8>) throws -> Result
   ) rethrows -> Result {
-    return try self.nulTerminatedUTF8.withUnsafeBufferPointer {
-      try body(UnsafePointer($0.baseAddress!))
+    return try self.utf8CString.withUnsafeBufferPointer {
+      try body($0.baseAddress!)
     }
   }
 }

stdlib/public/core/Pointer.swift

@@ -87,6 +87,6 @@ public // COMPILER_INTRINSIC
 func _convertConstStringToUTF8PointerArgument<
   ToPointer : _Pointer
 >(_ str: String) -> (AnyObject?, ToPointer) {
-  let utf8 = Array(str.nulTerminatedUTF8)
+  let utf8 = Array(str.utf8CString)
   return _convertConstArrayToPointerArgument(utf8)
 }

stdlib/public/core/StringUTF8.swift

@@ -383,35 +383,21 @@ extension String {
     return _core.elementWidth == 1 ? _core.startASCII : nil
   }
 
-  /// A contiguously stored null-terminated UTF-8 representation of
-  /// the string.
+  /// A contiguously stored null-terminated UTF-8 representation of the string.
   ///
-  /// To access the underlying memory, invoke
-  /// `withUnsafeBufferPointer` on the array.
+  /// To access the underlying memory, invoke `withUnsafeBufferPointer` on the
+  /// array.
   ///
   ///     let s = "Hello!"
-  ///     let bytes = s.nulTerminatedUTF8
+  ///     let bytes = s.utf8CString
   ///     print(bytes)
   ///     // Prints "[72, 101, 108, 108, 111, 33, 0]"
-  ///     
+  ///
   ///     bytes.withUnsafeBufferPointer { ptr in
-  ///         print(strlen(UnsafePointer(ptr.baseAddress!)))
+  ///         print(strlen(ptr.baseAddress!))
   ///     }
   ///     // Prints "6"
-  public var nulTerminatedUTF8: ContiguousArray<UTF8.CodeUnit> {
-    var result = ContiguousArray<UTF8.CodeUnit>()
-    result.reserveCapacity(utf8.count + 1)
-    result += utf8
-    result.append(0)
-    return result
-  }
-
-  /// A contiguously stored null-terminated UTF-8 representation of
-  /// the string.
-  ///
-  /// This is a variation on nulTerminatedUTF8 that creates an array
-  /// of element type CChar for use with CString API's.
-  public var nulTerminatedUTF8CString: ContiguousArray<CChar> {
+  public var utf8CString: ContiguousArray<CChar> {
     var result = ContiguousArray<CChar>()
     result.reserveCapacity(utf8.count + 1)
     for c in utf8 {
@@ -428,7 +414,11 @@ extension String {
     if ptr != nil {
       return try body(UnsafeBufferPointer(start: ptr, count: _core.count))
     }
-    return try nulTerminatedUTF8.withUnsafeBufferPointer(body)
+    var nullTerminatedUTF8 = ContiguousArray<UTF8.CodeUnit>()
+    nullTerminatedUTF8.reserveCapacity(utf8.count + 1)
+    nullTerminatedUTF8 += utf8
+    nullTerminatedUTF8.append(0)
+    return try nullTerminatedUTF8.withUnsafeBufferPointer(body)
   }
 
   /// Creates a string corresponding to the given sequence of UTF-8 code units.
@@ -725,3 +715,9 @@ extension String.UTF8View : CustomPlaygroundQuickLookable {
   }
 }
 
+extension String {
+  @available(*, unavailable, message: "Please use String.utf8CString instead.")
+  public var nulTerminatedUTF8: ContiguousArray<UTF8.CodeUnit> {
+    Builtin.unreachable()
+  }
+}

test/1_stdlib/Runtime.swift.gyb

@@ -13,20 +13,20 @@ import SwiftShims
 @_silgen_name("swift_demangle")
 public
 func _stdlib_demangleImpl(
-  mangledName: UnsafePointer<UInt8>?,
+  mangledName: UnsafePointer<CChar>?,
   mangledNameLength: UInt,
-  outputBuffer: UnsafeMutablePointer<UInt8>?,
+  outputBuffer: UnsafeMutablePointer<CChar>?,
   outputBufferSize: UnsafeMutablePointer<UInt>?,
   flags: UInt32
 ) -> UnsafeMutablePointer<CChar>?
 
 func _stdlib_demangleName(_ mangledName: String) -> String {
-  return mangledName.nulTerminatedUTF8.withUnsafeBufferPointer {
-    (mangledNameUTF8) in
+  return mangledName.utf8CString.withUnsafeBufferPointer {
+    (mangledNameUTF8CStr) in
 
     let demangledNamePtr = _stdlib_demangleImpl(
-      mangledName: mangledNameUTF8.baseAddress,
-      mangledNameLength: UInt(mangledNameUTF8.count - 1),
+      mangledName: mangledNameUTF8CStr.baseAddress,
+      mangledNameLength: UInt(mangledNameUTF8CStr.count - 1),
       outputBuffer: nil,
       outputBufferSize: nil,
       flags: 0)

test/1_stdlib/StringAPI.swift

@@ -483,19 +483,17 @@ CStringTests.test("String.decodeCString") {
   }
 }
 
-CStringTests.test("String.nulTerminatedUTF8") {
+CStringTests.test("String.utf8CString") {
   do {
     let (cstr, dealloc) = getASCIICString()
     let str = String(cString: cstr)
-    expectEqualCString(cstr, str.nulTerminatedUTF8)
-    expectEqualCString(cstr, str.nulTerminatedUTF8CString)
+    expectEqualCString(cstr, str.utf8CString)
     dealloc()
   }
   do {
     let (cstr, dealloc) = getNonASCIICString()
     let str = String(cString: cstr)
-    expectEqualCString(cstr, str.nulTerminatedUTF8)
-    expectEqualCString(cstr, str.nulTerminatedUTF8CString)
+    expectEqualCString(cstr, str.utf8CString)
     dealloc()
   }
 }

test/1_stdlib/TestData.swift

@@ -127,9 +127,11 @@ class TestData : TestDataSuper {
     // String of course has its own way to get data, but this way tests our own data struct
     func dataFrom(_ string : String) -> Data {
         // Create a Data out of those bytes
-        return string.nulTerminatedUTF8.withUnsafeBufferPointer { (ptr) in
-            // Subtract 1 so we don't get the null terminator byte. This matches NSString behavior.
-            return Data(bytes: ptr.baseAddress!, count: ptr.count - 1)
+        return string.utf8CString.withUnsafeBufferPointer { (ptr) in
+            ptr.baseAddress!.withMemoryRebound(to: UInt8.self, capacity: ptr.count) {
+                // Subtract 1 so we don't get the null terminator byte. This matches NSString behavior.
+                return Data(bytes: $0, count: ptr.count - 1)
+            }
         }
     }