Merge pull request #8770 from slavapestov/anyobject-removal-preparations

AnyObject removal preparations

Author: slavapestov

docs/ABI.rst

@@ -1044,7 +1044,8 @@ Types
   type ::= associated-type
   type ::= nominal-type
   type ::= protocol-list 'p'                 // existential type
-  type ::= protocol-list superclass 'XE'     // existential type with superclass
+  type ::= protocol-list superclass 'Xc'     // existential type with superclass
+  type ::= protocol-list 'Xl'                // existential type with AnyObject
   type ::= type-list 't'                     // tuple
   type ::= type generic-signature 'u'        // generic type
   type ::= 'x'                               // generic param, depth=0, idx=0

include/swift/AST/ASTContext.h

@@ -407,6 +407,9 @@ class ASTContext {
   /// Retrieve the declaration of the "pointee" property of a pointer type.
   VarDecl *getPointerPointeePropertyDecl(PointerTypeKind ptrKind) const;
 
+  /// Retrieve the type Swift.AnyObject.
+  CanType getAnyObjectType() const;
+
   /// Retrieve the type Swift.Never.
   CanType getNeverType() const;
 

include/swift/AST/DiagnosticsSema.def

@@ -419,8 +419,6 @@ WARNING(expr_keypath_swift3_objc_inference,none,
         "argument of '#keyPath' refers to property %0 in %1 that depends on "
         "'@objc' attribute inference deprecated in Swift 4",
         (DeclName, Identifier))
-ERROR(stdlib_anyobject_not_found,none,
-      "broken standard library: cannot find 'AnyObject' protocol", ())
 ERROR(expr_keypath_type_of_property,none,
       "cannot refer to type member %0 within instance of type %1",
       (DeclName, Type))

include/swift/AST/ExistentialLayout.h

@@ -71,6 +71,8 @@ struct ExistentialLayout {
     return multipleProtocols;
   }
 
+  LayoutConstraint getLayoutConstraint() const;
+
 private:
   // Inline storage for 'protocols' member above when computing
   // layout of a single ProtocolType

include/swift/AST/Type.h

@@ -353,8 +353,6 @@ class CanType : public Type {
   static bool isAnyExistentialTypeImpl(CanType type);
   static void getExistentialTypeProtocolsImpl(CanType type,
                                     SmallVectorImpl<ProtocolDecl*> &protocols);
-  static void getAnyExistentialTypeProtocolsImpl(CanType type,
-                                    SmallVectorImpl<ProtocolDecl*> &protocols);
   static bool isObjCExistentialTypeImpl(CanType type);
   static CanType getAnyOptionalObjectTypeImpl(CanType type,
                                               OptionalTypeKind &kind);
@@ -413,11 +411,6 @@ class CanType : public Type {
   void getExistentialTypeProtocols(
       SmallVectorImpl<ProtocolDecl *> &protocols);
 
-  /// Given that this type is any kind of existential, return its
-  /// protocols in a canonical order.
-  void getAnyExistentialTypeProtocols(
-      SmallVectorImpl<ProtocolDecl *> &protocols);
-
   /// Break an existential down into a set of constraints.
   ExistentialLayout getExistentialLayout();
 
@@ -434,11 +427,6 @@ class CanType : public Type {
   NominalTypeDecl *getAnyNominal() const;
   GenericTypeDecl *getAnyGeneric() const;
 
-  /// Returns information about the layout constraint represented by
-  /// this type. If this type does not represent a layout constraint,
-  /// it returns an empty LayoutConstraint.
-  LayoutConstraint getLayoutConstraint() const;
-
   CanType getAnyOptionalObjectType() const {
     OptionalTypeKind kind;
     return getAnyOptionalObjectTypeImpl(*this, kind);

include/swift/AST/Types.h

@@ -325,6 +325,15 @@ class alignas(1 << TypeAlignInBits) TypeBase {
   };
   enum { NumAnyMetatypeTypeBits = NumTypeBaseBits + 2 };
   static_assert(NumAnyMetatypeTypeBits <= 32, "fits in an unsigned");
+
+  struct ProtocolCompositionTypeBitfields {
+    unsigned : NumTypeBaseBits;
+    /// Whether we have an explicitly-stated class constraint not
+    /// implied by any of our members.
+    unsigned HasExplicitAnyObject : 1;
+  };
+  enum { NumProtocolCompositionTypeBits = NumTypeBaseBits + 1 };
+  static_assert(NumProtocolCompositionTypeBits <= 32, "fits in an unsigned");
 
   union {
     TypeBaseBitfields TypeBaseBits;
@@ -334,6 +343,7 @@ class alignas(1 << TypeAlignInBits) TypeBase {
     ArchetypeTypeBitfields ArchetypeTypeBits;
     SILFunctionTypeBitfields SILFunctionTypeBits;
     AnyMetatypeTypeBitfields AnyMetatypeTypeBits;
+    ProtocolCompositionTypeBitfields ProtocolCompositionTypeBits;
   };
 
 protected:
@@ -580,10 +590,6 @@ class alignas(1 << TypeAlignInBits) TypeBase {
   /// its list of protocols.
   void getExistentialTypeProtocols(SmallVectorImpl<ProtocolDecl *> &protocols);
 
-  /// Given that this type is any kind of existential type, produce
-  /// its list of protocols.
-  void getAnyExistentialTypeProtocols(SmallVectorImpl<ProtocolDecl *> &protocols);
-
   /// Break an existential down into a set of constraints.
   ExistentialLayout getExistentialLayout();
 
@@ -707,12 +713,6 @@ class alignas(1 << TypeAlignInBits) TypeBase {
   /// concrete types to form the argument type.
   bool isBindableTo(Type ty, LazyResolver *resolver);
 
-  /// \brief Retrieve the layout constraint of this type.
-  ///
-  /// \returns The layout constraint of this type, or a null layout constraint
-  ///          if it has no layout constraint.
-  LayoutConstraint getLayoutConstraint();
-
   /// \brief Determines whether this type is permitted as a method override
   /// of the \p other.
   bool canOverride(Type other, OverrideMatchMode matchMode,
@@ -3662,44 +3662,66 @@ END_CAN_TYPE_WRAPPER(ProtocolType, NominalType)
 /// protocol, then the canonical type is that protocol type. Otherwise, it is
 /// a composition of the protocols in that list.
 class ProtocolCompositionType : public TypeBase, public llvm::FoldingSetNode {
-  ArrayRef<Type> Protocols;
+  ArrayRef<Type> Members;
 
 public:
   /// \brief Retrieve an instance of a protocol composition type with the
-  /// given set of protocols.
-  static Type get(const ASTContext &C, ArrayRef<Type> Protocols);
+  /// given set of members.
+  static Type get(const ASTContext &C, ArrayRef<Type> Members,
+                  bool HasExplicitAnyObject);
 
-  /// \brief Retrieve the set of protocols composed to create this type.
-  ArrayRef<Type> getProtocols() const { return Protocols; }
+  /// \brief Retrieve the set of members composed to create this type.
+  ///
+  /// For non-canonical types, this can contain classes, protocols and
+  /// protocol compositions in any order. There can be at most one unique
+  /// class constraint, either stated directly or as recursive member.
+  ///
+  /// In canonical types, this list will contain the superclass first if
+  /// any, followed by zero or more protocols in a canonical sorted order,
+  /// minimized to remove duplicates or protocols implied by inheritance.
+  ///
+  /// Note that the list of members is not sufficient to uniquely identify
+  /// a protocol composition type; you also have to look at
+  /// hasExplicitAnyObject().
+  ArrayRef<Type> getMembers() const { return Members; }
 
   void Profile(llvm::FoldingSetNodeID &ID) {
-    Profile(ID, Protocols);
+    Profile(ID, Members, hasExplicitAnyObject());
   }
-  static void Profile(llvm::FoldingSetNodeID &ID, ArrayRef<Type> Protocols);
+  static void Profile(llvm::FoldingSetNodeID &ID,
+                      ArrayRef<Type> Members,
+                      bool HasExplicitAnyObject);
 
-  /// True if one or more of the protocols is class.
+  /// True if the composition requires the concrete conforming type to
+  /// be a class, either via a directly-stated superclass constraint or
+  /// one of its member protocols being class-constrained.
   bool requiresClass();
-  
+
+  /// True if the class requirement is stated directly via '& AnyObject'.
+  bool hasExplicitAnyObject() {
+    return ProtocolCompositionTypeBits.HasExplicitAnyObject;
+  }
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const TypeBase *T) {
     return T->getKind() == TypeKind::ProtocolComposition;
   }
 
 private:
   static ProtocolCompositionType *build(const ASTContext &C,
-                                        ArrayRef<Type> Protocols);
+                                        ArrayRef<Type> Members,
+                                        bool HasExplicitAnyObject);
 
-  ProtocolCompositionType(const ASTContext *ctx, ArrayRef<Type> protocols,
+  ProtocolCompositionType(const ASTContext *ctx, ArrayRef<Type> members,
+                          bool hasExplicitAnyObject,
                           RecursiveTypeProperties properties)
     : TypeBase(TypeKind::ProtocolComposition, /*Context=*/ctx,
                properties),
-      Protocols(protocols) { }
+      Members(members) {
+    ProtocolCompositionTypeBits.HasExplicitAnyObject = hasExplicitAnyObject;
+  }
 };
 BEGIN_CAN_TYPE_WRAPPER(ProtocolCompositionType, Type)
-  /// In the canonical representation, these are all ProtocolTypes.
-  CanTypeArrayRef getProtocols() const {
-    return CanTypeArrayRef(getPointer()->getProtocols());
-  }
 END_CAN_TYPE_WRAPPER(ProtocolCompositionType, Type)
 
 /// LValueType - An l-value is a handle to a physical object.  The

include/swift/Demangling/DemangleNodes.def

@@ -124,6 +124,7 @@ NODE(ProtocolConformance)
 NODE(ProtocolDescriptor)
 NODE(ProtocolList)
 NODE(ProtocolListWithClass)
+NODE(ProtocolListWithAnyObject)
 NODE(ProtocolWitness)
 NODE(ProtocolWitnessTable)
 NODE(ProtocolWitnessTableAccessor)

include/swift/Demangling/Demangler.h

@@ -447,6 +447,7 @@ class Demangler : public NodeFactory {
   NodePointer demangleMetatypeRepresentation();
   NodePointer demangleFunctionEntity();
   NodePointer demangleEntity(Node::Kind Kind);
+  NodePointer demangleProtocolList();
   NodePointer demangleProtocolListType();
   NodePointer demangleGenericSignature(bool hasParamCounts);
   NodePointer demangleGenericRequirement();

include/swift/Runtime/Metadata.h

@@ -2441,6 +2441,11 @@ struct TargetExistentialTypeMetadata : public TargetMetadata<Runtime> {
     return Flags.getClassConstraint() == ProtocolClassConstraint::Class;
   }
 
+  const Metadata *getSuperclassConstraint() const {
+    // FIXME
+    return nullptr;
+  }
+
   static bool classof(const TargetMetadata<Runtime> *metadata) {
     return metadata->getKind() == MetadataKind::Existential;
   }
@@ -3176,7 +3181,9 @@ swift_getExistentialMetatypeMetadata(const Metadata *instanceType);
 /// referenced by \c protocols will be sorted in-place.
 SWIFT_RT_ENTRY_VISIBILITY
 const ExistentialTypeMetadata *
-swift_getExistentialTypeMetadata(size_t numProtocols,
+swift_getExistentialTypeMetadata(ProtocolClassConstraint classConstraint,
+                                 const Metadata *superclassConstraint,
+                                 size_t numProtocols,
                                  const ProtocolDescriptor **protocols)
     SWIFT_CC(RegisterPreservingCC);
 

include/swift/Runtime/RuntimeFunctions.def

@@ -791,12 +791,17 @@ FUNCTION(GetTupleMetadata3, swift_getTupleTypeMetadata3, DefaultCC,
               Int8PtrTy, WitnessTablePtrTy),
          ATTRS(NoUnwind, ReadOnly))
 
-// Metadata *swift_getExistentialTypeMetadata(size_t numProtocols,
+// Metadata *swift_getExistentialTypeMetadata(
+//                              ProtocolClassConstraint classConstraint,
+//                              const Metadata *superclassConstraint,
+//                              size_t numProtocols,
 //                              const protocol_descriptor_t * const *protocols);
+//
+// Note: ProtocolClassConstraint::Class is 0, ::Any is 1.
 FUNCTION(GetExistentialMetadata,
          swift_getExistentialTypeMetadata, RegisterPreservingCC,
          RETURNS(TypeMetadataPtrTy),
-         ARGS(SizeTy,
+         ARGS(Int1Ty, TypeMetadataPtrTy, SizeTy,
               ProtocolDescriptorPtrTy->getPointerTo()),
          ATTRS(NoUnwind, ReadOnly))
 

include/swift/Serialization/ModuleFormat.h

@@ -54,7 +54,7 @@ const uint16_t VERSION_MAJOR = 0;
 /// in source control, you should also update the comment to briefly
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
-const uint16_t VERSION_MINOR = 333; // Last change: AST constant_string_literal
+const uint16_t VERSION_MINOR = 334; // Last change: AnyObject bit in ProtocolCompositionType
 
 using DeclID = PointerEmbeddedInt<unsigned, 31>;
 using DeclIDField = BCFixed<31>;
@@ -660,6 +660,7 @@ namespace decls_block {
 
   using ProtocolCompositionTypeLayout = BCRecordLayout<
     PROTOCOL_COMPOSITION_TYPE,
+    BCFixed<1>,          // has AnyObject constraint
     BCArray<TypeIDField> // protocols
   >;
 

lib/AST/ASTContext.cpp

@@ -112,6 +112,9 @@ struct ASTContext::Implementation {
   /// The declaration of Swift.DefaultPrecedence.
   PrecedenceGroupDecl *DefaultPrecedence = nullptr;
 
+  /// The AnyObject type.
+  CanType AnyObjectType;
+
 #define KNOWN_STDLIB_TYPE_DECL(NAME, DECL_CLASS, NUM_GENERIC_PARAMS) \
   /** The declaration of Swift.NAME. */ \
   DECL_CLASS *NAME##Decl = nullptr;
@@ -415,7 +418,8 @@ ASTContext::ASTContext(LangOptions &langOpts, SearchPathOptions &SearchPathOpts,
     TheUnresolvedType(new (*this, AllocationArena::Permanent)
                       UnresolvedType(*this)),
     TheEmptyTupleType(TupleType::get(ArrayRef<TupleTypeElt>(), *this)),
-    TheAnyType(ProtocolCompositionType::get(*this, ArrayRef<Type>())),
+    TheAnyType(ProtocolCompositionType::get(*this, ArrayRef<Type>(),
+                                            /*hasExplicitAnyObject=*/false)),
     TheNativeObjectType(new (*this, AllocationArena::Permanent)
                            BuiltinNativeObjectType(*this)),
     TheBridgeObjectType(new (*this, AllocationArena::Permanent)
@@ -670,6 +674,29 @@ ASTContext::getPointerPointeePropertyDecl(PointerTypeKind ptrKind) const {
   llvm_unreachable("bad pointer kind");
 }
 
+CanType ASTContext::getAnyObjectType() const {
+  if (Impl.AnyObjectType) {
+    return Impl.AnyObjectType;
+  }
+
+  // Go find 'AnyObject' in the Swift module.
+  //
+  // FIXME: This is going away.
+  SmallVector<ValueDecl *, 1> results;
+  lookupInSwiftModule("AnyObject", results);
+  for (auto result : results) {
+    if (auto proto = dyn_cast<ProtocolDecl>(result)) {
+      Impl.AnyObjectType = proto->getDeclaredType()->getCanonicalType();
+      return Impl.AnyObjectType;
+    }
+  }
+
+  Impl.AnyObjectType = CanType(
+    ProtocolCompositionType::get(
+      *this, {}, /*hasExplicitAnyObject=*/true));
+  return Impl.AnyObjectType;
+}
+
 CanType ASTContext::getNeverType() const {
   return getNeverDecl()->getDeclaredType()->getCanonicalType();
 }
@@ -2834,15 +2861,16 @@ void ClassType::Profile(llvm::FoldingSetNodeID &ID, ClassDecl *D, Type Parent) {
 }
 
 ProtocolCompositionType *
-ProtocolCompositionType::build(const ASTContext &C, ArrayRef<Type> Protocols) {
+ProtocolCompositionType::build(const ASTContext &C, ArrayRef<Type> Members,
+                               bool HasExplicitAnyObject) {
   // Check to see if we've already seen this protocol composition before.
   void *InsertPos = nullptr;
   llvm::FoldingSetNodeID ID;
-  ProtocolCompositionType::Profile(ID, Protocols);
+  ProtocolCompositionType::Profile(ID, Members, HasExplicitAnyObject);
 
   bool isCanonical = true;
   RecursiveTypeProperties properties;
-  for (Type t : Protocols) {
+  for (Type t : Members) {
     if (!t->isCanonical())
       isCanonical = false;
     properties |= t->getRecursiveProperties();
@@ -2859,7 +2887,8 @@ ProtocolCompositionType::build(const ASTContext &C, ArrayRef<Type> Protocols) {
   auto compTy
     = new (C, arena)
         ProtocolCompositionType(isCanonical ? &C : nullptr,
-                                C.AllocateCopy(Protocols),
+                                C.AllocateCopy(Members),
+                                HasExplicitAnyObject,
                                 properties);
   C.Impl.getArena(arena).ProtocolCompositionTypes
     .InsertNode(compTy, InsertPos);
@@ -3510,17 +3539,21 @@ CanArchetypeType ArchetypeType::getOpened(Type existential,
   for (auto proto : layout.getProtocols())
     protos.push_back(proto->getDecl());
 
+  auto layoutConstraint = layout.getLayoutConstraint();
+
   auto arena = AllocationArena::Permanent;
   void *mem = ctx.Allocate(
       totalSizeToAlloc<ProtocolDecl *, Type, LayoutConstraint, UUID>(
-      protos.size(), layout.superclass ? 1 : 0, 0, 1),
+      protos.size(),
+      layout.superclass ? 1 : 0,
+      layoutConstraint ? 1 : 0, 1),
       alignof(ArchetypeType), arena);
 
   // FIXME: Pass in class layout constraint
   auto result =
       ::new (mem) ArchetypeType(ctx, existential,
                                 protos, layout.superclass,
-                                existential->getLayoutConstraint(), *knownID);
+                                layoutConstraint, *knownID);
   openedExistentialArchetypes[*knownID] = result;
 
   return CanArchetypeType(result);

lib/AST/ASTDumper.cpp

@@ -3075,7 +3075,9 @@ namespace {
     void visitProtocolCompositionType(ProtocolCompositionType *T,
                                       StringRef label) {
       printCommon(T, label, "protocol_composition_type");
-      for (auto proto : T->getProtocols()) {
+      if (T->hasExplicitAnyObject())
+        OS << " any_object";
+      for (auto proto : T->getMembers()) {
         printRec(proto);
       }
       OS << ")";