Merge pull request swiftlang#21130 from slavapestov/remove-property-behaviors

Remove property behaviors

Author: slavapestov

include/swift/AST/ASTContext.h

@@ -744,14 +744,6 @@ class ASTContext final {
                  DeclContext *dc,
                  ProtocolConformanceState state);
 
-  /// Produce a new normal conformance for a property behavior.
-  NormalProtocolConformance *
-  getBehaviorConformance(Type conformingType,
-                         ProtocolDecl *protocol,
-                         SourceLoc loc,
-                         AbstractStorageDecl *storage,
-                         ProtocolConformanceState state);
-
   /// Produce a self-conformance for the given protocol.
   SelfProtocolConformance *
   getSelfConformance(ProtocolDecl *protocol);

include/swift/AST/ASTMangler.h

@@ -123,8 +123,6 @@ class ASTMangler : public Mangler {
   std::string mangleClosureWitnessThunk(const ProtocolConformance *Conformance,
                                         const AbstractClosureExpr *Closure);
 
-  std::string mangleBehaviorInitThunk(const VarDecl *decl);
-
   std::string mangleGlobalVariableFull(const VarDecl *decl);
 
   std::string mangleGlobalInit(const VarDecl *decl, int counter,

include/swift/AST/Decl.h

@@ -4160,38 +4160,6 @@ class ProtocolDecl final : public NominalTypeDecl {
   }
 };
 
-/// Information about a behavior instantiated by a storage declaration.
-///
-/// TODO: Accessors, composed behaviors
-struct alignas(1 << 3) BehaviorRecord {
-  // The behavior name.
-  TypeRepr *ProtocolName;
-  // The parameter expression, if any.
-  Expr *Param;
-  
-  Optional<NormalProtocolConformance *> Conformance = None;
-  // The 'value' property from the behavior protocol that provides the property
-  // implementation.
-  VarDecl *ValueDecl = nullptr;
-  
-  // Storage declaration and initializer for use by definite initialization.
-  VarDecl *StorageDecl = nullptr;
-  ConcreteDeclRef InitStorageDecl = nullptr;
-  
-  bool needsInitialization() const {
-    assert((bool)StorageDecl == (bool)InitStorageDecl
-           && "DI state not consistent");
-    return StorageDecl != nullptr;
-  }
-  
-  BehaviorRecord(TypeRepr *ProtocolName,
-                 Expr *Param)
-    : ProtocolName(ProtocolName), Param(Param)
-  {}
-  
-  SourceLoc getLoc() const;
-};
-
 /// AbstractStorageDecl - This is the common superclass for VarDecl and
 /// SubscriptDecl, representing potentially settable memory locations.
 class AbstractStorageDecl : public ValueDecl {
@@ -4257,8 +4225,6 @@ class AbstractStorageDecl : public ValueDecl {
   };
 
   llvm::PointerIntPair<AccessorRecord*, 3, OptionalEnum<AccessLevel>> Accessors;
-  llvm::PointerIntPair<BehaviorRecord*, 3, OptionalEnum<AccessLevel>>
-    BehaviorInfo;
 
   void setFieldsFromImplInfo(StorageImplInfo implInfo) {
     Bits.AbstractStorageDecl.HasStorage = implInfo.hasStorage();
@@ -4401,9 +4367,6 @@ class AbstractStorageDecl : public ValueDecl {
   /// This should only be used by the ClangImporter.
   void setComputedSetter(AccessorDecl *Set);
 
-  /// Add a behavior to a property.
-  void addBehavior(TypeRepr *Type, Expr *Param);
-
   /// Add a synthesized getter.
   void setSynthesizedGetter(AccessorDecl *getter);
 
@@ -4547,28 +4510,6 @@ class AbstractStorageDecl : public ValueDecl {
   /// property from the given module?
   bool isResilient(ModuleDecl *M, ResilienceExpansion expansion) const;
 
-  /// Does the storage use a behavior?
-  bool hasBehavior() const {
-    return BehaviorInfo.getPointer() != nullptr;
-  }
-  
-  /// Does the storage use a behavior, and require definite initialization
-  /// analysis.
-  bool hasBehaviorNeedingInitialization() const {
-    if (auto behavior = getBehavior()) {
-      return behavior->needsInitialization();
-    }
-    return false;
-  }
-  
-  /// Get the behavior info.
-  const BehaviorRecord *getBehavior() const {
-    return BehaviorInfo.getPointer();
-  }
-  BehaviorRecord *getMutableBehavior() {
-    return BehaviorInfo.getPointer();
-  }
-
   void setIsValidKeyPathComponent(bool value) {
     Bits.AbstractStorageDecl.HasComputedValidKeyPathComponent = true;
     Bits.AbstractStorageDecl.ValidKeyPathComponent = value;
@@ -5560,9 +5501,6 @@ class FuncDecl : public AbstractFunctionDecl {
 
   TypeLoc FnRetType;
 
-  /// If this FuncDecl is an accessor for a property, this indicates
-  /// which property and what kind of accessor.
-  BehaviorRecord *BehaviorParamDecl = nullptr;
   OperatorDecl *Operator = nullptr;
 
 protected:
@@ -5709,16 +5647,6 @@ class FuncDecl : public AbstractFunctionDecl {
     return cast_or_null<FuncDecl>(AbstractFunctionDecl::getOverriddenDecl());
   }
 
-  /// Get the property behavior this function serves as a parameter for, if
-  /// any.
-  BehaviorRecord *getParamBehavior() const {
-    return BehaviorParamDecl;
-  }
-  
-  void setParamBehavior(BehaviorRecord *behavior) {
-    BehaviorParamDecl = behavior;
-  }
-  
   OperatorDecl *getOperatorDecl() const {
     return Operator;
   }

include/swift/AST/DiagnosticsParse.def

@@ -302,9 +302,6 @@ ERROR(getset_init,none,
       "variable with getter/setter cannot have an initial value", ())
 ERROR(getset_cannot_be_implied,none,
       "variable with implied type cannot have implied getter/setter", ())
-ERROR(behavior_multiple_vars,none,
-      "applying property behavior with parameter to multiple variables is "
-      "not supported", ())
 
 // Import
 ERROR(decl_expected_module_name,none,
@@ -862,10 +859,6 @@ ERROR(parameter_let_var_as_attr,none,
       (StringRef))
 
 
-ERROR(expected_behavior_name,none,
-      "expected behavior name after '[' in property declaration", ())
-
-
 WARNING(parameter_extraneous_double_up,none,
         "extraneous duplicate parameter name; %0 already has an argument "
         "label", (Identifier))

include/swift/AST/DiagnosticsSema.def

@@ -2452,63 +2452,6 @@ ERROR(self_in_nominal,none,
       "'Self' is only available in a protocol or as the result of a "
       "method in a class; did you mean '%0'?", (StringRef))
 
-// Property behaviors
-ERROR(property_behavior_not_protocol,none,
-      "property behavior name must refer to a protocol", ())
-ERROR(property_behavior_protocol_reqt_ambiguous,none,
-      "property behavior protocol has ambiguous %0 member", (Identifier))
-ERROR(property_behavior_protocol_no_value,none,
-      "property behavior protocol does not have a 'value' property", ())
-ERROR(property_behavior_protocol_no_initStorage,none,
-      "property behavior protocol has a 'storage' requirement but does not "
-      "have a static 'initStorage' method with the expected type %0 or %1",
-      (Type, Type))
-ERROR(property_behavior_unknown_requirement,none,
-      "property behavior protocol %0 has non-behavior requirement %1",
-      (Identifier, DeclBaseName))
-NOTE(property_behavior_unknown_requirement_here,none,
-     "declared here", ())
-NOTE(self_conformance_required_by_property_behavior,none,
-     "conformance to %0 required to contain an instance property with "
-     "behavior %1",
-     (Identifier, Identifier))
-NOTE(value_conformance_required_by_property_behavior,none,
-     "behavior %1 requires property type to conform to protocol %0",
-     (Identifier, Identifier))
-ERROR(property_behavior_with_self_requirement_not_in_type,none,
-      "property behavior %0 can only be used on instance properties "
-      "because it has 'Self' requirements",
-      (Identifier))
-ERROR(property_behavior_with_feature_not_supported,none,
-      "property behavior %0 with %1 is not supported outside of "
-      "type contexts",
-      (Identifier, StringRef))
-ERROR(property_behavior_value_type_doesnt_match,none,
-      "property behavior %0 provides 'value' property implementation with "
-      "type %1 that doesn't match type %2 of declared property %3",
-      (Identifier, Type, Identifier, Type))
-NOTE(property_behavior_value_decl_here,none,
-     "'value' property declared here", ())
-ERROR(property_behavior_invalid_parameter_reqt,none,
-      "property behavior %0 has a 'parameter' requirement that is "
-      "static or generic", (Identifier))
-ERROR(property_behavior_requires_parameter,none,
-      "property behavior %0 requires a parameter in the declaration of %1",
-      (Identifier, Identifier))
-ERROR(property_behavior_invalid_initializer,none,
-      "initializer expression provided, but property behavior %0 does not "
-      "use it",
-      (Identifier))
-ERROR(property_behavior_unsupported_initializer,none,
-      "property behaviors do not support destructuring initialization of "
-      "multiple properties", ())
-ERROR(property_behavior_invalid_parameter,none,
-      "parameter expression provided, but property behavior %0 does not "
-      "use it",
-      (Identifier))
-ERROR(property_behavior_conformance_broken,none,
-      "property behavior for %0 in type %1 is broken", (DeclName, Type))
-
 //------------------------------------------------------------------------------
 // MARK: Type Check Attributes
 //------------------------------------------------------------------------------

include/swift/AST/Expr.h

@@ -112,12 +112,6 @@ enum class AccessSemantics : uint8_t {
   /// implementation of this storage, bypassing any possibility of override.
   DirectToImplementation,
 
-  /// On a property or subscript reference, this is an access to a property
-  /// behavior that may be an initialization. Reads always go through the
-  /// 'get' accessor on the property. Writes may go through the 'init' or
-  /// 'set' logic of the behavior based on its initialization state.
-  BehaviorInitialization,
-
   /// This is an ordinary access to a declaration, using whatever
   /// polymorphism is expected.
   Ordinary,

include/swift/AST/ProtocolConformance.h

@@ -308,12 +308,6 @@ class alignas(1 << DeclAlignInBits) ProtocolConformance {
   void printName(raw_ostream &os,
                  const PrintOptions &PO = PrintOptions()) const;
 
-  /// True if the conformance is for a property behavior instantiation.
-  bool isBehaviorConformance() const;
-
-  /// Get the property declaration for a behavior conformance, if this is one.
-  AbstractStorageDecl *getBehaviorDecl() const;
-
   /// Get any additional requirements that are required for this conformance to
   /// be satisfied, if it is possible for them to be computed.
   Optional<ArrayRef<Requirement>> getConditionalRequirementsIfAvailable() const;
@@ -351,9 +345,6 @@ class RootProtocolConformance : public ProtocolConformance {
   /// Retrieve the location of this conformance.
   SourceLoc getLoc() const;
 
-  /// Is this a behavior conformance?
-  bool isBehaviorConformance() const;
-
   bool isInvalid() const;
 
   /// Whether this conformance is weak-imported.
@@ -425,14 +416,11 @@ class NormalProtocolConformance : public RootProtocolConformance,
   /// The location of this protocol conformance in the source.
   SourceLoc Loc;
 
-  using Context = llvm::PointerUnion<DeclContext *, AbstractStorageDecl *>;
-
   /// The declaration context containing the ExtensionDecl or
-  /// NominalTypeDecl that declared the conformance, or the VarDecl whose
-  /// behavior this conformance represents.
+  /// NominalTypeDecl that declared the conformance.
   ///
   /// Also stores the "invalid" bit.
-  llvm::PointerIntPair<Context, 1, bool> ContextAndInvalid;
+  llvm::PointerIntPair<DeclContext *, 1, bool> ContextAndInvalid;
 
   /// The reason that this conformance exists.
   ///
@@ -491,18 +479,6 @@ class NormalProtocolConformance : public RootProtocolConformance,
            "ProtocolConformances should store interface types");
   }
 
-  NormalProtocolConformance(Type conformingType,
-                            ProtocolDecl *protocol,
-                            SourceLoc loc, AbstractStorageDecl *behaviorStorage,
-                            ProtocolConformanceState state)
-    : RootProtocolConformance(ProtocolConformanceKind::Normal, conformingType),
-      ProtocolAndState(protocol, state), Loc(loc),
-      ContextAndInvalid(behaviorStorage, false)
-  {
-    assert(!conformingType->hasArchetype() &&
-           "ProtocolConformances should store interface types");
-  }
-
   void resolveLazyInfo() const;
 
   void differenceAndStoreConditionalRequirements() const;
@@ -517,12 +493,7 @@ class NormalProtocolConformance : public RootProtocolConformance,
   /// Get the declaration context that contains the conforming extension or
   /// nominal type declaration.
   DeclContext *getDeclContext() const {
-    auto context = ContextAndInvalid.getPointer();
-    if (auto DC = context.dyn_cast<DeclContext *>()) {
-      return DC;
-    } else {
-      return context.get<AbstractStorageDecl *>()->getDeclContext();
-    }
+    return ContextAndInvalid.getPointer();
   }
 
   /// Get any additional requirements that are required for this conformance to
@@ -607,17 +578,6 @@ class NormalProtocolConformance : public RootProtocolConformance,
   /// This only matters to the AST verifier.
   bool isLazilyLoaded() const { return Loader != nullptr; }
 
-  /// True if the conformance describes a property behavior.
-  bool isBehaviorConformance() const {
-    return ContextAndInvalid.getPointer().is<AbstractStorageDecl *>();
-  }
-
-  /// Return the declaration using the behavior for this conformance, or null
-  /// if this isn't a behavior conformance.
-  AbstractStorageDecl *getBehaviorDecl() const {
-    return ContextAndInvalid.getPointer().dyn_cast<AbstractStorageDecl *>();
-  }
-
   /// A "retroactive" conformance is one that is defined in a module that
   /// is neither the module that defines the protocol nor the module that
   /// defines the conforming type.
@@ -811,12 +771,6 @@ class SelfProtocolConformance : public RootProtocolConformance {
   }
 };
 
-inline bool RootProtocolConformance::isBehaviorConformance() const {
-  if (auto normal = dyn_cast<NormalProtocolConformance>(this))
-    return normal->isBehaviorConformance();
-  return false;
-}
-
 /// Specialized protocol conformance, which projects a generic protocol
 /// conformance to one of the specializations of the generic type.
 ///

include/swift/AST/StorageImpl.h

@@ -80,10 +80,6 @@ class AccessStrategy {
     /// that storage directly.
     Storage,
 
-    /// The decl is a VarDecl with storage defined by a property behavior;
-    /// this access may initialize or reassign the storage based on dataflow.
-    BehaviorStorage,
-
     /// Directly call an accessor of some sort.  The strategy includes
     /// an accessor kind.
     DirectToAccessor,
@@ -107,7 +103,7 @@ class AccessStrategy {
 
   AccessStrategy(Kind kind)
     : TheKind(kind) {
-    assert(kind == Storage || kind == BehaviorStorage);
+    assert(kind == Storage);
   }
 
   AccessStrategy(Kind kind, AccessorKind accessor)
@@ -131,10 +127,6 @@ class AccessStrategy {
     return { Storage };
   }
 
-  static AccessStrategy getBehaviorStorage() {
-    return { BehaviorStorage };
-  }
-
   static AccessStrategy getAccessor(AccessorKind accessor, bool dispatched) {
     return { dispatched ? DispatchToAccessor : DirectToAccessor, accessor };
   }

include/swift/Basic/LangOptions.h

@@ -213,9 +213,6 @@ namespace swift {
     /// Enable experimental #assert feature.
     bool EnableExperimentalStaticAssert = false;
 
-    /// Enable experimental property behavior feature.
-    bool EnableExperimentalPropertyBehaviors = false;
-
     /// Staging flag for treating inout parameters as Thread Sanitizer
     /// accesses.
     bool DisableTsanInoutInstrumentation = false;

include/swift/Option/FrontendOptions.td

@@ -326,10 +326,6 @@ def enable_experimental_static_assert :
   Flag<["-"], "enable-experimental-static-assert">,
   HelpText<"Enable experimental #assert">;
 
-def enable_experimental_property_behaviors :
-  Flag<["-"], "enable-experimental-property-behaviors">,
-  HelpText<"Enable experimental property behaviors">;
-  
 def enable_deserialization_recovery :
   Flag<["-"], "enable-deserialization-recovery">,
   HelpText<"Attempt to recover from missing xrefs (etc) in swiftmodules">;