---

yaml
---
r: 339710
b: refs/heads/rxwei-patch-1
c: af7b461
h: refs/heads/master

Author: DougGregor

[refs]

@@ -1015,7 +1015,7 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2018-08-18-a: b10b1fce14385faa6d44f6b933e95
 refs/heads/rdar-43033749-fix-batch-mode-no-diags-swift-5.0-branch: a14e64eaad30de89f0f5f0b2a782eed7ecdcb255
 refs/heads/revert-19006-error-bridging-integer-type: 8a9065a3696535305ea53fe9b71f91cbe6702019
 refs/heads/revert-19050-revert-19006-error-bridging-integer-type: ecf752d54b05dd0a20f510f0bfa54a3fec3bcaca
-refs/heads/rxwei-patch-1: 22c099504667f8ce7a9af7048cbc3d23103c56b9
+refs/heads/rxwei-patch-1: af7b461db2d25dc54e52ab50026e569505abb7eb
 refs/heads/shahmishal-patch-1: e58ec0f7488258d42bef51bc3e6d7b3dc74d7b2a
 refs/heads/typelist-existential: 4046359efd541fb5c72d69a92eefc0a784df8f5e
 refs/tags/swift-4.2-DEVELOPMENT-SNAPSHOT-2018-08-20-a: 4319ba09e4fb8650ee86061075c74a016b6baab9

branches/rxwei-patch-1/lib/Sema/CodeSynthesis.cpp

@@ -1794,7 +1794,7 @@ PropertyDelegateBackingPropertyInfoRequest::evaluate(Evaluator &evaluator,
   VarDecl *storageVar = nullptr;
   if (delegateInfo.delegateValueVar) {
     storageVar = synthesizePropertyDelegateStorageDelegateProperty(
-        ctx, var, delegateType, delegateInfo.delegateValueVar);
+        ctx, var, storageType, delegateInfo.delegateValueVar);
   }
 
   // Get the property delegate information.

branches/rxwei-patch-1/stdlib/public/core/StringBridge.swift

@@ -90,6 +90,26 @@ internal func _cocoaStringCopyUTF8(
   return len == converted ? count : nil
 }
 
+@_effects(readonly)
+internal func _cocoaStringUTF8Count(
+  _ target: _CocoaString,
+  range: Range<Int>
+) -> Int? {
+  var count = 0
+  let len = _stdlib_binary_CFStringGetLength(target)
+  let converted = _swift_stdlib_CFStringGetBytes(
+    target,
+    _swift_shims_CFRange(location: range.startIndex, length: range.count),
+    kCFStringEncodingUTF8,
+    0,
+    0,
+    UnsafeMutablePointer<UInt8>(Builtin.inttoptr_Word(0._builtinWordValue)),
+    0,
+    &count
+  )
+  return converted == len ? count : nil
+}
+
 @_effects(readonly)
 internal func _cocoaStringCompare(
   _ string: _CocoaString, _ other: _CocoaString

branches/rxwei-patch-1/stdlib/public/core/StringUTF8View.swift

@@ -470,14 +470,31 @@ extension String.UTF8View {
   @_effects(releasenone)
   internal func _foreignDistance(from i: Index, to j: Index) -> Int {
     _internalInvariant(_guts.isForeign)
+    
+    #if _runtime(_ObjC)
+    // Currently, foreign  means NSString
+    if let count = _cocoaStringUTF8Count(
+      _guts._object.cocoaObject,
+      range: i._encodedOffset ..< j._encodedOffset
+    ) {
+      //_cocoaStringUTF8Count gave us the scalar aligned count, but we still
+      //need to compensate for sub-scalar indexing, e.g. if `i` is in the middle
+      //of a two-byte UTF8 scalar.
+      let refinedCount = count - (i.transcodedOffset + j.transcodedOffset)
+      _internalInvariant(refinedCount == _distance(from: i, to: j))
+      return refinedCount
+    }
+    #endif
+
     return _distance(from: i, to: j)
+   
   }
 
   @usableFromInline @inline(never)
   @_effects(releasenone)
   internal func _foreignCount() -> Int {
     _internalInvariant(_guts.isForeign)
-    return _distance(from: startIndex, to: endIndex)
+    return _foreignDistance(from: startIndex, to: endIndex)
   }
 }
 

branches/rxwei-patch-1/test/decl/var/property_delegates.swift

@@ -667,6 +667,26 @@ func testStorageRef(tsr: TestStorageRef) {
   _ = tsr.$$x // expected-error{{'$$x' is inaccessible due to 'private' protection level}}
 }
 
+// rdar://problem/50873275 - crash when using wrapper with delegateValue in
+// generic type.
+@_propertyDelegate
+struct InitialValueWrapperWithStorageRef<T> {
+  var value: T
+
+  init(initialValue: T) {
+    value = initialValue
+  }
+
+  var delegateValue: Wrapper<T> {
+    return Wrapper(value: value)
+  }
+}
+
+struct TestGenericStorageRef<T> {
+  struct Inner { }
+  @InitialValueWrapperWithStorageRef var inner: Inner = Inner()
+}
+
 // ---------------------------------------------------------------------------
 // Misc. semantic issues
 // ---------------------------------------------------------------------------