Remove _StringBuffer 🎉🎉🎉

Author: lorentey

stdlib/public/core/Builtin.swift

@@ -579,14 +579,6 @@ extension ManagedBufferPointer {
     self._nativeBuffer = buffer
   }
 }
-extension _StringBuffer {
-  @_inlineable
-  public // FIXME: String Guts
-  var _nativeObject: _BuiltinNativeObject {
-    @inline(__always)
-    get { return _storage._nativeBuffer }
-  }
-}
 
 /// Create a `BridgeObject` around the given `nativeObject` with the
 /// given spare bits.

stdlib/public/core/CMakeLists.txt

@@ -123,7 +123,6 @@ set(SWIFTLIB_ESSENTIAL
   StringHashable.swift  # ORDER DEPENDENCY: Must precede String.swift
   String.swift
   StringBridge.swift
-  StringBuffer.swift
   StringComparable.swift
   StringGuts.swift
   StringObject.swift

stdlib/public/core/CString.swift

@@ -195,11 +195,14 @@ internal func _decodeCString<Encoding : _UnicodeEncoding>(
 -> (result: String, repairsMade: Bool)? {
 
   let buffer = UnsafeBufferPointer<Encoding.CodeUnit>(
-    start: cString, count: length)
+    start: cString,
+    count: length)
 
-  let (stringBuffer, hadError) = _StringBuffer.fromCodeUnits(
-    buffer, encoding: encoding, repairIllFormedSequences: isRepairing)
-  return stringBuffer.map {
-    (result: String(_storage: $0), repairsMade: hadError)
+  let (guts, hadError) = _StringGuts.fromCodeUnits(
+    buffer,
+    encoding: encoding,
+    repairIllFormedSequences: isRepairing)
+  return guts.map {
+    (result: String($0), repairsMade: hadError)
   }
 }

stdlib/public/core/GroupInfo.json

@@ -12,7 +12,6 @@
     "StaticString.swift",
     "String.swift",
     "StringBridge.swift",
-    "StringBuffer.swift",
     "StringCharacterView.swift",
     "StringComparable.swift",
     "StringObject.swift",

stdlib/public/core/String.swift

@@ -1042,28 +1042,6 @@ extension String {
     Builtin.unreachable()
   }
 
-  @_inlineable // FIXME(sil-serialize-all)
-  public // SPI(Foundation)
-  init(_storage: _StringBuffer) { // FIXME: Replace with _SwiftStringStorage
-    if _storage.elementWidth == 1 {
-      let native = _SwiftStringStorage<UInt8>.create(
-        capacity: _storage.capacity,
-        count: _storage.usedCount)
-      native.start.initialize(
-        from: _storage.start.assumingMemoryBound(to: UInt8.self),
-        count: _storage.usedCount)
-      _guts = _StringGuts(native)
-    } else {
-      let native = _SwiftStringStorage<UInt16>.create(
-        capacity: _storage.capacity,
-        count: _storage.usedCount)
-      native.start.initialize(
-        from: _storage.start.assumingMemoryBound(to: UInt16.self),
-        count: _storage.usedCount)
-      _guts = _StringGuts(native)
-    }
-  }
-
   @_inlineable // FIXME(sil-serialize-all)
   public
   init<CodeUnit>(_storage: _SwiftStringStorage<CodeUnit>)
@@ -1275,7 +1253,7 @@ internal func _nativeUnicodeUppercaseString(_ str: String) -> String {
       dest, Int32(utf16.count), // FIXME: handle overflow case
       utf16.start, Int32(utf16.count))
   }
-  return String(_storage: buffer)
+  return String(_storage: storage)
 }
 #endif
 

stdlib/public/core/StringBridge.swift

@@ -48,29 +48,6 @@ func _stdlib_binary_CFStringGetCharactersPtr(
 /// Loading Foundation initializes these function variables
 /// with useful values
 
-/// Produces a `_StringBuffer` from a given subrange of a source
-/// `_CocoaString`, having the given minimum capacity.
-@_versioned // FIXME(sil-serialize-all)
-@inline(never) // Hide the CF dependency
-internal func _cocoaStringToContiguous(
-  source: _CocoaString, range: Range<Int>, minimumCapacity: Int
-) -> _StringBuffer {
-  _sanityCheck(_swift_stdlib_CFStringGetCharactersPtr(source) == nil,
-    "Known contiguously stored strings should already be converted to Swift")
-
-  let startIndex = range.lowerBound
-  let count = range.upperBound - startIndex
-
-  let buffer = _StringBuffer(capacity: max(count, minimumCapacity), 
-                             initialSize: count, elementWidth: 2)
-
-  _swift_stdlib_CFStringGetCharacters(
-    source, _swift_shims_CFRange(location: startIndex, length: count), 
-    buffer.start.assumingMemoryBound(to: _swift_shims_UniChar.self))
-  
-  return buffer
-}
-
 /// Copies the entire contents of a _CocoaString into contiguous
 /// storage of sufficient capacity.
 @_versioned // FIXME(sil-serialize-all)