---

yaml
---
r: 341983
b: refs/heads/rxwei-patch-1
c: e5e469f
h: refs/heads/master
i:
  341981: 7dfb18b
  341979: 99bbbbc
  341975: 0cd47b9
  341967: 39dc72e
  341951: 4c2deab

Author: nkcsgexi

[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: ab8699195840c05ddc9e1e4f0c6d26812f90654b
+refs/heads/rxwei-patch-1: e5e469f330b4d9a168e55f96943bbb082b388003
 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/CHANGELOG.md

@@ -26,27 +26,24 @@ CHANGELOG
 Swift Next
 ----------
 
-* [SR-8974][]:
+* [SR-4206][]:
 
-  Duplicate tuple element labels are no longer allowed, because it leads
-  to incorrect behavior. For example:
+  A method override is no longer allowed to have a generic signature with 
+  requirements not imposed by the base method. For example:
 
   ```
-  let dupLabels: (foo: Int, foo: Int) = (foo: 1, foo: 2)
-
-  enum Foo { case bar(x: Int, x: Int) }
-  let f: Foo = .bar(x: 0, x: 1)
+  protocol P {}
+  
+  class Base {
+    func foo<T>(arg: T) {}
+  }
+  
+  class Derived: Base {
+    override func foo<T: P>(arg: T) {}
+  }
   ```
 
-  will now be diagnosed as an error. 
-
-  Note: You can still use duplicate labels when declaring functions and
-  subscripts, as long as the internal labels are different. For example:
-
-  ```
-  func foo(bar x: Int, bar y: Int) {}
-  subscript(a x: Int, a y: Int) -> Int {}
-  ```
+  will now be diagnosed as an error.
 
 * [SR-6118][]:
 
@@ -68,6 +65,28 @@ Swift Next
 Swift 5.1
 ---------
 
+* [SR-8974][]:
+
+  Duplicate tuple element labels are no longer allowed, because it leads
+  to incorrect behavior. For example:
+
+  ```
+  let dupLabels: (foo: Int, foo: Int) = (foo: 1, foo: 2)
+
+  enum Foo { case bar(x: Int, x: Int) }
+  let f: Foo = .bar(x: 0, x: 1)
+  ```
+
+  will now be diagnosed as an error. 
+
+  Note: You can still use duplicate argument labels when declaring functions and
+  subscripts, as long as the internal parameter names are different. For example:
+
+  ```
+  func foo(bar x: Int, bar y: Int) {}
+  subscript(a x: Int, a y: Int) -> Int {}
+  ```
+
 * [SE-0244][]:
 
   Functions can now hide their concrete return type by declaring what protocols
@@ -7708,6 +7727,7 @@ Swift 1.0
 [SR-2608]: <https://bugs.swift.org/browse/SR-2608>
 [SR-2672]: <https://bugs.swift.org/browse/SR-2672>
 [SR-2688]: <https://bugs.swift.org/browse/SR-2688>
+[SR-4206]: <https://bugs.swift.org/browse/SR-4206>
 [SR-4248]: <https://bugs.swift.org/browse/SR-4248>
 [SR-5581]: <https://bugs.swift.org/browse/SR-5581>
 [SR-5719]: <https://bugs.swift.org/browse/SR-5719>

branches/rxwei-patch-1/README.md

@@ -76,7 +76,7 @@ Please make sure you use Python 2.x. Python 3.x is not supported currently.
 
 #### macOS
 
-To build for macOS, you need [Xcode 11 beta](https://developer.apple.com/xcode/downloads/).
+To build for macOS, you need [Xcode 11 beta 4](https://developer.apple.com/xcode/downloads/).
 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.

branches/rxwei-patch-1/cmake/modules/AddSwift.cmake

@@ -1512,10 +1512,9 @@ function(add_swift_host_library name)
 
   if(NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
     swift_install_in_component(TARGETS ${name}
-                               ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-                               LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-                               RUNTIME DESTINATION bin
-                               COMPONENT dev)
+      ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT dev
+      LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT dev
+      RUNTIME DESTINATION bin COMPONENT dev)
   endif()
 
   swift_is_installing_component(dev is_installing)
@@ -2139,10 +2138,15 @@ function(add_swift_target_library name)
 
       if(sdk STREQUAL WINDOWS AND CMAKE_SYSTEM_NAME STREQUAL Windows)
         swift_install_in_component(TARGETS ${name}-windows-${SWIFT_PRIMARY_VARIANT_ARCH}
-                                   RUNTIME DESTINATION "bin"
-                                   LIBRARY DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/${resource_dir}/${resource_dir_sdk_subdir}/${SWIFT_PRIMARY_VARIANT_ARCH}"
-                                   ARCHIVE DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/${resource_dir}/${resource_dir_sdk_subdir}/${SWIFT_PRIMARY_VARIANT_ARCH}"
-                                   COMPONENT "${SWIFTLIB_INSTALL_IN_COMPONENT}"
+                                   RUNTIME
+                                     DESTINATION "bin"
+                                     COMPONENT "${SWIFTLIB_INSTALL_IN_COMPONENT}"
+                                   LIBRARY
+                                     DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/${resource_dir}/${resource_dir_sdk_subdir}/${SWIFT_PRIMARY_VARIANT_ARCH}"
+                                     COMPONENT "${SWIFTLIB_INSTALL_IN_COMPONENT}"
+                                   ARCHIVE
+                                     DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/${resource_dir}/${resource_dir_sdk_subdir}/${SWIFT_PRIMARY_VARIANT_ARCH}"
+                                     COMPONENT "${SWIFTLIB_INSTALL_IN_COMPONENT}"
                                    PERMISSIONS ${file_permissions})
       else()
         swift_install_in_component(FILES "${UNIVERSAL_LIBRARY_NAME}"
@@ -2423,8 +2427,9 @@ function(add_swift_host_tool executable)
     ${ASHT_UNPARSED_ARGUMENTS})
 
   swift_install_in_component(TARGETS ${executable}
-                             RUNTIME DESTINATION bin
-                             COMPONENT ${ASHT_SWIFT_COMPONENT})
+                             RUNTIME
+                               DESTINATION bin
+                               COMPONENT ${ASHT_SWIFT_COMPONENT})
 
   swift_is_installing_component(${ASHT_SWIFT_COMPONENT} is_installing)
 

branches/rxwei-patch-1/docs/StandardLibraryProgrammersManual.md

@@ -50,6 +50,19 @@ TODO: Should this subsume or link to [AccessControlInStdlib.rst](https://github.
 
 Optionals can be unwrapped with `!`, which triggers a trap on nil. Alternatively, they can be `.unsafelyUnwrapped()`, which will check and trap in debug builds of user code. Internal to the standard library is `._unsafelyUnwrappedUnchecked()` which will only check and trap in debug builds of the standard library itself. These correspond directly with `_precondition`, `_debugPrecondition`, and `_sanityCheck`. See [that section](#precondition) for details.
 
+#### UnsafeBitCast and Casting References
+
+In general `unsafeBitCast` should be avoided because it's correctness relies on subtle assumptions that will never be enforced, and it indicates a bug in Swift's type system that should be fixed. It's less bad for non-pointer trivial types. Pointer casting should go through one of the memory binding API instead as a last resort.
+
+Reference casting is more interesting. References casting can include converting to an Optional reference and converting from a class constrained existential.
+
+The regular `as` operator should be able to convert between reference types with full dynamic checking.
+
+`unsafeDownCast` is just as capable, but is only dynamically checked in debug mode or if the cast requires runtime support.
+
+`_unsafeUncheckedDowncast` is the same but is only dynamically checked in the stdlib asserts build, or if the cast requires runtime support.
+
+`_unsafeReferenceCast` is only dynamically checked if the cast requires runtime support. Additionally, it does not impose any static `AnyObject` constraint on the incoming reference. This is useful in a generic context where the object-ness can be determined dynamically, as done in some bridged containers.
 
 ### Builtins
 

branches/rxwei-patch-1/include/swift/AST/Builtins.def

@@ -314,6 +314,11 @@ BUILTIN_SIL_OPERATION(BeginUnpairedModifyAccess, "beginUnpairedModifyAccess",
 /// be a pointer to an UnsafeValueBuffer that records an in progress access.
 BUILTIN_SIL_OPERATION(EndUnpairedAccess, "endUnpairedAccess", Special)
 
+/// condfail(Int1) -> ()
+/// Triggers a runtime failure if the condition is true.
+/// This builtin is deprecated. Use condfail_message instead.
+BUILTIN_SIL_OPERATION(LegacyCondFail, "condfail", Special)
+
 /// fixLifetime(T) -> ()
 /// Fixes the lifetime of any heap references in a value.
 BUILTIN_SIL_OPERATION(FixLifetime, "fixLifetime", Special)
@@ -400,9 +405,9 @@ BUILTIN_RUNTIME_CALL(IsOptionalType, "isOptional", "")
           BUILTIN(Id, Name, Attrs)
 #endif
 
-/// condfail(Int1, RawPointer) -> ()
+/// condfail_message(Int1, RawPointer) -> ()
 /// Triggers a runtime failure if the condition is true.
-BUILTIN_MISC_OPERATION(CondFail, "condfail", "", Special)
+BUILTIN_MISC_OPERATION(CondFailMessage, "condfail_message", "", Special)
 
 /// Sizeof has type T.Type -> Int
 BUILTIN_MISC_OPERATION(Sizeof, "sizeof", "n", Special)

branches/rxwei-patch-1/include/swift/AST/Decl.h

@@ -4105,7 +4105,20 @@ class ProtocolDecl final : public NominalTypeDecl {
   /// by this protocol.
   const Requirement *RequirementSignature = nullptr;
 
-  bool requiresClassSlow();
+  /// Returns the cached result of \c requiresClass or \c None if it hasn't yet
+  /// been computed.
+  Optional<bool> getCachedRequiresClass() const {
+    if (Bits.ProtocolDecl.RequiresClassValid)
+      return Bits.ProtocolDecl.RequiresClass;
+
+    return None;
+  }
+
+  /// Caches the result of \c requiresClass
+  void setCachedRequiresClass(bool requiresClass) {
+    Bits.ProtocolDecl.RequiresClassValid = true;
+    Bits.ProtocolDecl.RequiresClass = requiresClass;
+  }
 
   bool existentialConformsToSelfSlow();
 
@@ -4120,6 +4133,7 @@ class ProtocolDecl final : public NominalTypeDecl {
   friend class SuperclassDeclRequest;
   friend class SuperclassTypeRequest;
   friend class RequirementSignatureRequest;
+  friend class ProtocolRequiresClassRequest;
   friend class TypeChecker;
 
 public:
@@ -4183,19 +4197,7 @@ class ProtocolDecl final : public NominalTypeDecl {
   }
 
   /// True if this protocol can only be conformed to by class types.
-  bool requiresClass() const {
-    if (Bits.ProtocolDecl.RequiresClassValid)
-      return Bits.ProtocolDecl.RequiresClass;
-
-    return const_cast<ProtocolDecl *>(this)->requiresClassSlow();
-  }
-
-  /// Specify that this protocol is class-bounded, e.g., because it was
-  /// annotated with the 'class' keyword.
-  void setRequiresClass(bool requiresClass = true) {
-    Bits.ProtocolDecl.RequiresClassValid = true;
-    Bits.ProtocolDecl.RequiresClass = requiresClass;
-  }
+  bool requiresClass() const;
 
   /// Determine whether an existential conforming to this protocol can be
   /// matched with a generic type parameter constrained to this protocol.

branches/rxwei-patch-1/include/swift/AST/DiagnosticsCommon.def

@@ -153,6 +153,12 @@ ERROR(circular_class_inheritance,none,
 ERROR(circular_enum_inheritance,none,
       "%0 has a raw type that depends on itself", (Identifier))
 
+ERROR(circular_protocol_def,none,
+      "protocol %0 refines itself", (Identifier))
+
+NOTE(kind_declname_declared_here,none,
+     "%0 %1 declared here", (DescriptiveDeclKind, DeclName))
+
 #ifndef DIAG_NO_UNDEF
 # if defined(DIAG)
 #  undef DIAG

branches/rxwei-patch-1/include/swift/AST/DiagnosticsParse.def

@@ -762,6 +762,13 @@ ERROR(extra_rbracket,PointsToFirstBadToken,
       "unexpected ']' in type; did you mean to write an array type?", ())
 ERROR(extra_colon,PointsToFirstBadToken,
       "unexpected ':' in type; did you mean to write a dictionary type?", ())
+WARNING(subscript_array_element, none,
+        "unexpected subscript in array literal; did you mean to write two "
+        "separate elements instead?", ())
+NOTE(subscript_array_element_fix_it_add_comma, none, "add a separator between "
+     "the elements", ())
+NOTE(subscript_array_element_fix_it_remove_space, none,
+     "remove the space between the elements to silence this warning", ())
 
 // Tuple Types
 ERROR(expected_rparen_tuple_type_list,none,
@@ -854,6 +861,8 @@ ERROR(expected_parameter_name,PointsToFirstBadToken,
       "expected parameter name followed by ':'", ())
 ERROR(expected_parameter_colon,PointsToFirstBadToken,
       "expected ':' following argument label and parameter name", ())
+ERROR(expected_assignment_instead_of_comparison_operator,none,
+      "expected '=' instead of '==' to assign default value for parameter", ())
 ERROR(missing_parameter_type,PointsToFirstBadToken,
       "parameter requires an explicit type", ())
 ERROR(multiple_parameter_ellipsis,none,

branches/rxwei-patch-1/include/swift/AST/DiagnosticsSema.def

@@ -37,8 +37,6 @@
   DIAG(NOTE,ID,Options,Text,Signature)
 #endif
 
-NOTE(kind_declname_declared_here,none,
-     "%0 %1 declared here", (DescriptiveDeclKind, DeclName))
 NOTE(decl_declared_here,none,
      "%0 declared here", (DeclName))
 NOTE(kind_declared_here,none,
@@ -2037,8 +2035,6 @@ ERROR(typealias_outside_of_protocol,none,
       "type alias %0 can only be used with a concrete type or "
       "generic parameter base", (Identifier))
 
-ERROR(circular_protocol_def,none,
-      "protocol %0 refines itself", (Identifier))
 ERROR(objc_protocol_inherits_non_objc_protocol,none,
       "@objc protocol %0 cannot refine non-@objc protocol %1", (Type, Type))
 

branches/rxwei-patch-1/include/swift/AST/TypeCheckRequests.h

@@ -176,6 +176,31 @@ class IsObjCRequest :
   void cacheResult(bool value) const;
 };
 
+/// Determine whether the given protocol declaration is class-bounded.
+class ProtocolRequiresClassRequest:
+    public SimpleRequest<ProtocolRequiresClassRequest,
+                         bool(ProtocolDecl *),
+                         CacheKind::SeparatelyCached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<bool> evaluate(Evaluator &evaluator, ProtocolDecl *decl) const;
+
+public:
+  // Cycle handling.
+  void diagnoseCycle(DiagnosticEngine &diags) const;
+  void noteCycleStep(DiagnosticEngine &diags) const;
+
+  // Separate caching.
+  bool isCached() const { return true; }
+  Optional<bool> getCachedResult() const;
+  void cacheResult(bool value) const;
+};
+
 /// Determine whether the given declaration is 'final'.
 class IsFinalRequest :
     public SimpleRequest<IsFinalRequest,

branches/rxwei-patch-1/include/swift/AST/TypeCheckerTypeIDZone.def

@@ -19,6 +19,7 @@ SWIFT_TYPEID(SuperclassTypeRequest)
 SWIFT_TYPEID(EnumRawTypeRequest)
 SWIFT_TYPEID(OverriddenDeclsRequest)
 SWIFT_TYPEID(IsObjCRequest)
+SWIFT_TYPEID(ProtocolRequiresClassRequest)
 SWIFT_TYPEID(IsFinalRequest)
 SWIFT_TYPEID(IsDynamicRequest)
 SWIFT_TYPEID(RequirementRequest)

branches/rxwei-patch-1/include/swift/AST/Types.h

@@ -461,6 +461,10 @@ class alignas(1 << TypeAlignInBits) TypeBase {
   /// types, optionals, etc.
   TypeBase *reconstituteSugar(bool Recursive);
 
+  // If this type is a syntax sugar type, desugar it. Also desugar any nested
+  // syntax sugar types.
+  TypeBase *getWithoutSyntaxSugar();
+
   /// getASTContext - Return the ASTContext that this type belongs to.
   ASTContext &getASTContext() {
     // If this type is canonical, it has the ASTContext in it.

branches/rxwei-patch-1/include/swift/ClangImporter/ClangImporterOptions.h

@@ -100,6 +100,10 @@ class ClangImporterOptions {
   /// When set, don't enforce warnings with -Werror.
   bool DebuggerSupport = false;
 
+  /// When set, clobber the Clang instance's virtual file system with the Swift
+  /// virtual file system.
+  bool ForceUseSwiftVirtualFileSystem = false;
+
   /// Return a hash code of any components from these options that should
   /// contribute to a Swift Bridging PCH hash.
   llvm::hash_code getPCHHashComponents() const {

branches/rxwei-patch-1/include/swift/Parse/Parser.h

@@ -1435,6 +1435,8 @@ class Parser {
 
   UnresolvedDeclRefExpr *parseExprOperator();
 
+  void validateCollectionElement(ParserResult<Expr> element);
+
   //===--------------------------------------------------------------------===//
   // Statement Parsing
 

branches/rxwei-patch-1/include/swift/Strings.h

@@ -54,7 +54,8 @@ struct BuiltinNameStringLiteral {
   const StringLiteral literal;
 
   constexpr operator StringRef() const { return literal; }
-  constexpr const StringRef getWithoutPrefix() const {
+
+  StringRef getWithoutPrefix() const {
     return literal.drop_front(BUILTIN_TYPE_NAME_PREFIX.size());
   }
 };