//===--- Features.def - Swift Features Metaprogramming ----------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2021 - 2025 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file defines macros used for macro-metaprogramming with language
// features.
//
//
// LANGUAGE_FEATURE(FeatureName, SENumber, Description)
//
//   The LANGUAGE_FEATURE macro describes each named feature that is
//   introduced in Swift. It allows Swift code to check for a particular
//   feature with "#if $FeatureName" in source code.
//
//     FeatureName: The name given to this feature to be used in source code,
//       e.g., AsyncAwait.
//     SENumber: The number assigned to this feature in the Swift Evolution
//       process, or 0 if there isn't one.
//     Description: A string literal describing the feature.
//
// Suppressible language features can be suppressed when printing
// an interface without having to suppress the entire declaration they're
// contained within.  The declaration will be emitted multiple times,
// each with a subset of the suppressible features.  To avoid combinatoric
// re-emission, we assume a linear history: later features in this file
// imply the existence of earlier features.  (This only needs to apply to
// suppressible features.)
//
// Sometimes, certain declarations will conflict with existing declarations
// when printed with a suppressible feature disabled. The attribute
// @_disallowFeatureSuppression can be used to suppress feature suppression on
// a particular declaration.
//
// If suppressing a feature in general is problematic, but it's okay to
// suppress it for specific declarations, the feature can be made
// conditionally suppressible.  Declarations opt in to suppression with
// the @_allowFeatureSuppression attribute.
//
// BASELINE_LANGUAGE_FEATURE is the same as LANGUAGE_FEATURE, but is used
// for features that can be assumed to be available in any Swift compiler that
// will be used to process the textual interface files produced by this
// Swift compiler.
//
// OPTIONAL_LANGUAGE_FEATURE is the same as LANGUAGE_FEATURE, but describes
// accepted features that can be enabled independently of language mode and
// are not scheduled to be enabled in some specific language mode. Examples
// of optional language features include strict memory safety checking (SE-0458)
// and Embedded Swift.
//===----------------------------------------------------------------------===//

#ifndef LANGUAGE_FEATURE
#  error define LANGUAGE_FEATURE before including Features.def
#endif

// A feature that's both suppressible and experimental.
// Delegates to whichever the includer defines.
#ifndef SUPPRESSIBLE_EXPERIMENTAL_FEATURE
#  if defined(SUPPRESSIBLE_LANGUAGE_FEATURE) && \
      defined(EXPERIMENTAL_FEATURE)
#    error ambiguous defines when including Features.def
#  elif defined(SUPPRESSIBLE_LANGUAGE_FEATURE)
#    define SUPPRESSIBLE_EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd) \
       SUPPRESSIBLE_LANGUAGE_FEATURE(FeatureName, 0, #FeatureName)
#  else
#    define SUPPRESSIBLE_EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd) \
       EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)
#  endif
#endif

// A feature that's both suppressible and upcoming.
// Delegates to whichever the includer defines.
#ifndef SUPPRESSIBLE_UPCOMING_FEATURE
#  if defined(SUPPRESSIBLE_LANGUAGE_FEATURE) && \
      defined(UPCOMING_FEATURE)
#    error ambiguous defines when including Features.def
#  elif defined(SUPPRESSIBLE_LANGUAGE_FEATURE)
#    define SUPPRESSIBLE_UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode) \
       SUPPRESSIBLE_LANGUAGE_FEATURE(FeatureName, SENumber, #FeatureName)
#  else
#    define SUPPRESSIBLE_UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode) \
       UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode)
#  endif
#endif

#ifndef SUPPRESSIBLE_LANGUAGE_FEATURE
  #define SUPPRESSIBLE_LANGUAGE_FEATURE(FeatureName, SENumber, Description)    \
    LANGUAGE_FEATURE(FeatureName, SENumber, Description)
#endif

#ifndef OPTIONAL_LANGUAGE_FEATURE
  #define OPTIONAL_LANGUAGE_FEATURE(FeatureName, SENumber, Description)        \
    LANGUAGE_FEATURE(FeatureName, SENumber, Description)
#endif

// A feature that's both conditionally-suppressible and experimental.
// Delegates to whichever the includer defines.
#ifndef CONDITIONALLY_SUPPRESSIBLE_EXPERIMENTAL_FEATURE
#  if defined(CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE) && \
      defined(EXPERIMENTAL_FEATURE)
#    error ambiguous defines when including Features.def
#  elif defined(CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE)
#    define CONDITIONALLY_SUPPRESSIBLE_EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd) \
       CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE(FeatureName, 0, #FeatureName)
#  else
#    define CONDITIONALLY_SUPPRESSIBLE_EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd) \
       EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)
#  endif
#endif

#ifndef CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE
  #define CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE(FeatureName, SENumber,   \
                                                      Description)             \
    LANGUAGE_FEATURE(FeatureName, SENumber, Description)
#endif

// An upcoming feature that supports migration mode.
//
// If the feature is source-breaking and provides for a
// mechanical code migration, it should implement migration mode.
//
// Migration mode is a feature-oriented code migration mechanism: a mode
// of operation that should produce compiler warnings with attached
// fix-its that can be applied to preserve the behavior of the code once
// the upcoming feature is enacted.
// These warnings must belong to a diagnostic group named after the
// feature. Migration mode itself *and* the fix-its it produces must be
// source and binary compatible with how the code is compiled when the
// feature is disabled.
#ifndef MIGRATABLE_UPCOMING_FEATURE
  #if defined(UPCOMING_FEATURE)
    #define MIGRATABLE_UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode)   \
      UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode)
  #else
    #define MIGRATABLE_UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode)   \
      LANGUAGE_FEATURE(FeatureName, SENumber, #FeatureName)
  #endif
#endif

// See `MIGRATABLE_UPCOMING_FEATURE`.
#ifndef MIGRATABLE_EXPERIMENTAL_FEATURE
  #if defined(EXPERIMENTAL_FEATURE)
    #define MIGRATABLE_EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)       \
      EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)
  #else
    #define MIGRATABLE_EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)       \
      LANGUAGE_FEATURE(FeatureName, 0, #FeatureName)
  #endif
#endif

#ifndef MIGRATABLE_OPTIONAL_LANGUAGE_FEATURE
  #define MIGRATABLE_OPTIONAL_LANGUAGE_FEATURE(FeatureName, SENumber, Name)   \
      OPTIONAL_LANGUAGE_FEATURE(FeatureName, SENumber, #Name)
#endif

#ifndef UPCOMING_FEATURE
  #define UPCOMING_FEATURE(FeatureName, SENumber, LanguageMode)                \
    LANGUAGE_FEATURE(FeatureName, SENumber, #FeatureName)
#endif

#ifndef EXPERIMENTAL_FEATURE
  // Warning: setting `AvailableInProd` to `true` on a feature means that the
  // flag cannot be dropped in the future.
  #define EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)                   \
    LANGUAGE_FEATURE(FeatureName, 0, #FeatureName)
#endif

#ifndef EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE
#  define EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE(FeatureName, AvailableInProd) \
     EXPERIMENTAL_FEATURE(FeatureName, AvailableInProd)
#endif

#ifndef BASELINE_LANGUAGE_FEATURE
  #define BASELINE_LANGUAGE_FEATURE(FeatureName, SENumber, Description)        \
    LANGUAGE_FEATURE(FeatureName, SENumber, Description)
#endif

BASELINE_LANGUAGE_FEATURE(AsyncAwait, 296, "async/await")
BASELINE_LANGUAGE_FEATURE(EffectfulProp, 310, "Effectful properties")
BASELINE_LANGUAGE_FEATURE(MarkerProtocol, 0, "@_marker protocol")
BASELINE_LANGUAGE_FEATURE(Actors, 0, "actors")
BASELINE_LANGUAGE_FEATURE(ConcurrentFunctions, 0, "@concurrent functions")
BASELINE_LANGUAGE_FEATURE(RethrowsProtocol, 0, "@rethrows protocol")
BASELINE_LANGUAGE_FEATURE(GlobalActors, 316, "Global actors")
BASELINE_LANGUAGE_FEATURE(BuiltinJob, 0, "Builtin.Job type")
BASELINE_LANGUAGE_FEATURE(Sendable, 0, "Sendable and @Sendable")
BASELINE_LANGUAGE_FEATURE(BuiltinExecutor, 0, "Builtin.Executor type")
BASELINE_LANGUAGE_FEATURE(BuiltinContinuation, 0, "Continuation builtins")
BASELINE_LANGUAGE_FEATURE(BuiltinHopToActor, 0, "Builtin.HopToActor")
BASELINE_LANGUAGE_FEATURE(BuiltinTaskGroupWithArgument, 0, "TaskGroup builtins")
BASELINE_LANGUAGE_FEATURE(InheritActorContext, 0, "@_inheritActorContext attribute")
BASELINE_LANGUAGE_FEATURE(ImplicitSelfCapture, 0, "@_implicitSelfCapture attribute")
BASELINE_LANGUAGE_FEATURE(BuiltinBuildTaskExecutorRef, 0, "TaskExecutor-building builtins")
BASELINE_LANGUAGE_FEATURE(BuiltinBuildExecutor, 0, "Executor-building builtins")
BASELINE_LANGUAGE_FEATURE(BuiltinBuildComplexEqualityExecutor, 0, "Executor-building for 'complexEquality executor' builtins")
BASELINE_LANGUAGE_FEATURE(BuiltinBuildMainExecutor, 0, "MainActor executor building builtin")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskOwnedTaskExecutor, 0, "Task create with owned TaskExecutor")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskName, 0, "Task create with a name")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskInGroup, 0, "Task create in task group builtin with extra flags")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskInGroupWithExecutor, 0, "Task create in task group builtin with extra flags")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncDiscardingTaskInGroup, 0, "Task create in discarding task group builtin, accounting for the Void return type")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskWithExecutor, 0, "Task create builtin with extra executor preference")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncDiscardingTaskInGroupWithExecutor, 0, "Task create in discarding task group with extra executor preference")
BASELINE_LANGUAGE_FEATURE(BuiltinStackAlloc, 0, "Builtin.stackAlloc")
BASELINE_LANGUAGE_FEATURE(BuiltinUnprotectedStackAlloc, 0, "Builtin.unprotectedStackAlloc")
BASELINE_LANGUAGE_FEATURE(BuiltinTaskRunInline, 0, "Builtin.taskRunInline")
BASELINE_LANGUAGE_FEATURE(BuiltinUnprotectedAddressOf, 0, "Builtin.unprotectedAddressOf")
BASELINE_LANGUAGE_FEATURE(NewCxxMethodSafetyHeuristics, 0, "Only import C++ methods that return pointers (projections) on owned types as unsafe")
BASELINE_LANGUAGE_FEATURE(SpecializeAttributeWithAvailability, 0, "@_specialize attribute with availability")
BASELINE_LANGUAGE_FEATURE(BuiltinAssumeAlignment, 0, "Builtin.assumeAlignment")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateTaskGroupWithFlags, 0, "Builtin.createTaskGroupWithFlags")
BASELINE_LANGUAGE_FEATURE(UnsafeInheritExecutor, 0, "@_unsafeInheritExecutor")
BASELINE_LANGUAGE_FEATURE(PrimaryAssociatedTypes2, 346, "Primary associated types")
BASELINE_LANGUAGE_FEATURE(UnavailableFromAsync, 0, "@_unavailableFromAsync")
BASELINE_LANGUAGE_FEATURE(NoAsyncAvailability, 340, "@available(*, noasync)")
BASELINE_LANGUAGE_FEATURE(AssociatedTypeAvailability, 0, "Availability on associated types")
BASELINE_LANGUAGE_FEATURE(AsyncSequenceFailure, 0, "Failure associated type on AsyncSequence and AsyncIteratorProtocol")
BASELINE_LANGUAGE_FEATURE(BuiltinIntLiteralAccessors, 368, "Builtin.IntLiteral accessors")
BASELINE_LANGUAGE_FEATURE(Macros, 0, "Macros")
BASELINE_LANGUAGE_FEATURE(FreestandingExpressionMacros, 382, "Expression macros")
BASELINE_LANGUAGE_FEATURE(AttachedMacros, 389, "Attached macros")
BASELINE_LANGUAGE_FEATURE(ExtensionMacros, 402, "Extension macros")
BASELINE_LANGUAGE_FEATURE(MoveOnly, 390, "noncopyable types")
BASELINE_LANGUAGE_FEATURE(MoveOnlyResilientTypes, 390, "non-@frozen noncopyable types with library evolution")
BASELINE_LANGUAGE_FEATURE(ParameterPacks, 393, "Value and type parameter packs")
BASELINE_LANGUAGE_FEATURE(LexicalLifetimes, 0, "@_eagerMove/@_noEagerMove/@_lexicalLifetimes annotations")
BASELINE_LANGUAGE_FEATURE(FreestandingMacros, 397, "freestanding declaration macros")
BASELINE_LANGUAGE_FEATURE(RetroactiveAttribute, 364, "@retroactive")
BASELINE_LANGUAGE_FEATURE(ExtensionMacroAttr, 0, "@attached(extension)")
BASELINE_LANGUAGE_FEATURE(TypedThrows, 413, "Typed throws")
BASELINE_LANGUAGE_FEATURE(OptionalIsolatedParameters, 420, "Optional isolated parameters")
BASELINE_LANGUAGE_FEATURE(ExpressionMacroDefaultArguments, 422, "Expression macro as caller-side default argument")
BASELINE_LANGUAGE_FEATURE(BuiltinStoreRaw, 0, "Builtin.storeRaw")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateTask, 0, "Builtin.createTask and Builtin.createDiscardingTask")
BASELINE_LANGUAGE_FEATURE(AssociatedTypeImplements, 0, "@_implements on associated types")
BASELINE_LANGUAGE_FEATURE(BuiltinAddressOfRawLayout, 0, "Builtin.addressOfRawLayout")
BASELINE_LANGUAGE_FEATURE(MoveOnlyPartialConsumption, 429, "Partial consumption of noncopyable values")
BASELINE_LANGUAGE_FEATURE(BitwiseCopyable, 426, "BitwiseCopyable protocol")
BASELINE_LANGUAGE_FEATURE(NoncopyableGenerics, 427, "Noncopyable generics")
BASELINE_LANGUAGE_FEATURE(NoncopyableGenerics2, 427, "Noncopyable generics alias")
BASELINE_LANGUAGE_FEATURE(ConformanceSuppression, 426, "Suppressible inferred conformances")
BASELINE_LANGUAGE_FEATURE(BitwiseCopyable2, 426, "BitwiseCopyable feature")
BASELINE_LANGUAGE_FEATURE(BodyMacros, 415, "Function body macros")
LANGUAGE_FEATURE(SendingArgsAndResults, 430, "Sending arg and results")
BASELINE_LANGUAGE_FEATURE(BorrowingSwitch, 432, "Noncopyable type pattern matching")
BASELINE_LANGUAGE_FEATURE(IsolatedAny, 431, "@isolated(any) function types")
LANGUAGE_FEATURE(IsolatedAny2, 431, "@isolated(any) function types")
LANGUAGE_FEATURE(ObjCImplementation, 436, "@objc @implementation extensions")
BASELINE_LANGUAGE_FEATURE(NonescapableTypes, 446, "Nonescapable types")
BASELINE_LANGUAGE_FEATURE(BuiltinEmplaceTypedThrows, 0, "Builtin.emplace typed throws")
BASELINE_LANGUAGE_FEATURE(MemorySafetyAttributes, 458, "@unsafe attribute")
BASELINE_LANGUAGE_FEATURE(ValueGenerics, 452, "Value generics feature (integer generics)")
LANGUAGE_FEATURE(RawIdentifiers, 451, "Raw identifiers")
LANGUAGE_FEATURE(SendableCompletionHandlers, 463, "Objective-C completion handler parameters are imported as @Sendable")
LANGUAGE_FEATURE(AsyncExecutionBehaviorAttributes, 0, "@concurrent and nonisolated(nonsending)")
LANGUAGE_FEATURE(IsolatedConformances, 407, "Global-actor isolated conformances")
BASELINE_LANGUAGE_FEATURE(ValueGenericsNameLookup, 452, "Value generics appearing as static members for namelookup")
LANGUAGE_FEATURE(GeneralizedIsSameMetaTypeBuiltin, 465, "Builtin.is_same_metatype with support for noncopyable/nonescapable types")
SUPPRESSIBLE_LANGUAGE_FEATURE(ABIAttributeSE0479, 479, "@abi attribute on functions, initializers, properties, and subscripts")
LANGUAGE_FEATURE(AlwaysInheritActorContext, 472, "@_inheritActorContext(always)")
LANGUAGE_FEATURE(BuiltinSelect, 0, "Builtin.select")
LANGUAGE_FEATURE(BuiltinInterleave, 0, "Builtin.interleave and Builtin.deinterleave")
LANGUAGE_FEATURE(BuiltinVectorsExternC, 0, "Extern C support for Builtin vector types")
LANGUAGE_FEATURE(AddressOfProperty2, 0, "Builtin.unprotectedAddressOf properties")
LANGUAGE_FEATURE(NonescapableAccessorOnTrivial, 0, "Support UnsafeMutablePointer.mutableSpan")
BASELINE_LANGUAGE_FEATURE(LayoutPrespecialization, 0, "Layout pre-specialization")
BASELINE_LANGUAGE_FEATURE(IsolatedDeinit, 371, "isolated deinit")
LANGUAGE_FEATURE(InlineArrayTypeSugar, 483, "Type sugar for InlineArray")
LANGUAGE_FEATURE(LifetimeDependenceMutableAccessors, 0, "Support mutable accessors returning ~Escapable results")
LANGUAGE_FEATURE(InoutLifetimeDependence, 0, "Support @_lifetime(&)")
SUPPRESSIBLE_LANGUAGE_FEATURE(NonexhaustiveAttribute, 487, "Nonexhaustive Enums")
LANGUAGE_FEATURE(ModuleSelector, 491, "Module selectors (`Module::name` syntax)")
LANGUAGE_FEATURE(BuiltinConcurrencyStackNesting, 0, "Concurrency Stack Nesting Builtins")

// Swift 6
UPCOMING_FEATURE(ConciseMagicFile, 274, 6)
UPCOMING_FEATURE(ForwardTrailingClosures, 286, 6)
UPCOMING_FEATURE(StrictConcurrency, 0337, 6)
UPCOMING_FEATURE(BareSlashRegexLiterals, 354, 6)
UPCOMING_FEATURE(DeprecateApplicationMain, 383, 6)
UPCOMING_FEATURE(ImportObjcForwardDeclarations, 384, 6)
UPCOMING_FEATURE(DisableOutwardActorInference, 401, 6)
UPCOMING_FEATURE(IsolatedDefaultValues, 411, 6)
UPCOMING_FEATURE(GlobalConcurrency, 412, 6)
UPCOMING_FEATURE(InferSendableFromCaptures, 418, 6)
UPCOMING_FEATURE(ImplicitOpenExistentials, 352, 6)
UPCOMING_FEATURE(RegionBasedIsolation, 414, 6)
UPCOMING_FEATURE(DynamicActorIsolation, 423, 6)
UPCOMING_FEATURE(NonfrozenEnumExhaustivity, 192, 6)
UPCOMING_FEATURE(GlobalActorIsolatedTypesUsability, 0434, 6)

// Swift 7
MIGRATABLE_UPCOMING_FEATURE(ExistentialAny, 335, 7)
UPCOMING_FEATURE(InternalImportsByDefault, 409, 7)
MIGRATABLE_UPCOMING_FEATURE(MemberImportVisibility, 444, 7)
MIGRATABLE_UPCOMING_FEATURE(InferIsolatedConformances, 470, 7)
MIGRATABLE_UPCOMING_FEATURE(NonisolatedNonsendingByDefault, 461, 7)
UPCOMING_FEATURE(ImmutableWeakCaptures, 481, 7)

// Optional language features / modes

/// Diagnose uses of language constructs and APIs that can violate memory
/// safety.
MIGRATABLE_OPTIONAL_LANGUAGE_FEATURE(StrictMemorySafety, 458, "Strict memory safety")

OPTIONAL_LANGUAGE_FEATURE(LibraryEvolution, 0, "Library evolution")

// Experimental features

EXPERIMENTAL_FEATURE(StaticAssert, false)
EXPERIMENTAL_FEATURE(NamedOpaqueTypes, false)
EXPERIMENTAL_FEATURE(FlowSensitiveConcurrencyCaptures, false)
EXPERIMENTAL_FEATURE(CodeItemMacros, false)
EXPERIMENTAL_FEATURE(PreambleMacros, false)
EXPERIMENTAL_FEATURE(MacrosOnImports, true)
EXPERIMENTAL_FEATURE(TupleConformances, false)
EXPERIMENTAL_FEATURE(FullTypedThrows, false)
EXPERIMENTAL_FEATURE(SameElementRequirements, false)
EXPERIMENTAL_FEATURE(KeyPathWithMethodMembers, false)

// Whether to emit an Embedded Swift module with "deferred" code generation,
// meaning that the only code that will be emitted into the object file is
// code that was marked as "never emit into client". For everything else,
// Swift still store the SIL and emit it into the client only when used.
EXPERIMENTAL_FEATURE(DeferredCodeGen, true)

// Whether to compile scripts lazily in immediate mode
EXPERIMENTAL_FEATURE(LazyImmediate, false)

// FIXME: MoveOnlyClasses is not intended to be in production,
// but our tests currently rely on it, and we want to run those
// tests in non-asserts builds too.
EXPERIMENTAL_FEATURE(MoveOnlyClasses, true)
EXPERIMENTAL_FEATURE(NoImplicitCopy, true)
EXPERIMENTAL_FEATURE(OldOwnershipOperatorSpellings, true)
EXPERIMENTAL_FEATURE(MoveOnlyEnumDeinits, true)
EXPERIMENTAL_FEATURE(MoveOnlyTuples, true)
EXPERIMENTAL_FEATURE(MoveOnlyPartialReinitialization, true)
EXPERIMENTAL_FEATURE(ConsumeSelfInDeinit, true)

EXPERIMENTAL_FEATURE(AccessLevelOnImport, true)

/// Disable the special behavior of of explicit 'nonisolated' vs. being
/// implicitly nonisolated.
EXPERIMENTAL_FEATURE(NoExplicitNonIsolated, true)

/// Enables a module to allow non resilient access from other
/// modules within a package if built from source.
EXPERIMENTAL_FEATURE(AllowNonResilientAccessInPackage, false)

/// Enables a client module within a package to bypass resilient
/// access (at use site) to decls defined in another module within
/// the same package.
EXPERIMENTAL_FEATURE(ClientBypassResilientAccessInPackage, false)

/// Enables serialization of package decls and bodies and performs
/// CMO within a package.
EXPERIMENTAL_FEATURE(PackageCMO, false)

/// Whether to enable experimental layout string value witnesses
EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE(LayoutStringValueWitnesses, true)
EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE(LayoutStringValueWitnessesInstantiation, true)

/// Whether to enable experimental differentiable programming features:
/// `@differentiable` declaration attribute, etc.
EXPERIMENTAL_FEATURE(DifferentiableProgramming, false)

/// Whether to enable forward mode differentiation.
EXPERIMENTAL_FEATURE(ForwardModeDifferentiation, false)

/// Whether to enable experimental `AdditiveArithmetic` derived
/// conformances.
EXPERIMENTAL_FEATURE(AdditiveArithmeticDerivedConformances, false)

/// Enables opaque type erasure without also enabling implict dynamic
EXPERIMENTAL_FEATURE(OpaqueTypeErasure, true)

/// Whether to perform round-trip testing of the Swift Swift parser.
EXPERIMENTAL_FEATURE(ParserRoundTrip, false)

/// Whether to perform validation of the parse tree produced by the Swift
/// Swift parser.
EXPERIMENTAL_FEATURE(ParserValidation, false)

/// Whether to perform validation of the unqualified lookup produced by
/// ASTScope and SwiftLexicalLookup
EXPERIMENTAL_FEATURE(UnqualifiedLookupValidation, false)

/// Enables implicit some while also enabling existential `any`
EXPERIMENTAL_FEATURE(ImplicitSome, false)

/// Parse using the Swift (swift-syntax) parser and use ASTGen to generate the
/// corresponding syntax tree.
EXPERIMENTAL_FEATURE(ParserASTGen, false)

/// Parse using the Swift (swift-syntax) parser and use ASTGen to generate the
/// corresponding syntax tree.
EXPERIMENTAL_FEATURE(BuiltinMacros, false)

/// Generate bindings for functions that 'throw' in the C++ section of the generated Clang header.
EXPERIMENTAL_FEATURE(GenerateBindingsForThrowingFunctionsInCXX, false)

/// Enable reference bindings.
EXPERIMENTAL_FEATURE(ReferenceBindings, true)

/// Enable the explicit 'import Builtin' and allow Builtin usage.
EXPERIMENTAL_FEATURE(BuiltinModule, true)

/// Enable extended callbacks (with additional parameters) to be used when the
/// "playground transform" is enabled.
EXPERIMENTAL_FEATURE(PlaygroundExtendedCallbacks, true)

/// Enable 'then' statements.
EXPERIMENTAL_FEATURE(ThenStatements, false)

/// Enable 'do' expressions.
EXPERIMENTAL_FEATURE(DoExpressions, false)

/// Enable 'for' expressions.
EXPERIMENTAL_FEATURE(ForExpressions, false)

/// Enable implicitly treating the last expression in a function, closure,
/// and 'if'/'switch' expression as the result.
EXPERIMENTAL_FEATURE(ImplicitLastExprResults, false)

/// Enable the `@_rawLayout` attribute.
EXPERIMENTAL_FEATURE(RawLayout, true)

/// Enables the "embedded" swift mode (no runtime).
EXPERIMENTAL_FEATURE(Embedded, true)

/// Enables importing the Volatile module
EXPERIMENTAL_FEATURE(Volatile, true)

// LEGACY: Enables ~Copyable and ~Escapable annotations on associatedtype declarations.
EXPERIMENTAL_FEATURE(SuppressedAssociatedTypes, true)

// Enables ~Copyable and ~Escapable annotations on associatedtype declarations,
// and infers defaults for them.
EXPERIMENTAL_FEATURE(SuppressedAssociatedTypesWithDefaults, true)

/// Allow destructuring stored `let` bindings in structs.
EXPERIMENTAL_FEATURE(StructLetDestructuring, true)

/// Enable returning non-escapable types from functions.
EXPERIMENTAL_FEATURE(LifetimeDependence, true)

/// Enable the `@_staticExclusiveOnly` attribute.
EXPERIMENTAL_FEATURE(StaticExclusiveOnly, true)

/// Enable the ManualOwnership diagnostic groups:
///   * -Wwarning SemanticCopies
///   * -Wwarning DynamicExclusivity
EXPERIMENTAL_FEATURE(ManualOwnership, false)

/// Enable the @extractConstantsFromMembers attribute.
EXPERIMENTAL_FEATURE(ExtractConstantsFromMembers, false)

// Group Main Actor Isolation Errors by Scope
EXPERIMENTAL_FEATURE(GroupActorErrors, true)

// Enable explicit isolation of closures.
EXPERIMENTAL_FEATURE(ClosureIsolation, true)

// Enable @implementation on extensions of ObjC classes with non-fixed layout
// due to resilient stored properties. Requires OS support; this flag exists for
// staging purposes.
EXPERIMENTAL_FEATURE(ObjCImplementationWithResilientStorage, true)

// Enable @sensitive attribute.
EXPERIMENTAL_FEATURE(Sensitive, true)

// Enable the stdlib @DebugDescription macro.
EXPERIMENTAL_FEATURE(DebugDescriptionMacro, true)

EXPERIMENTAL_FEATURE(ReinitializeConsumeInMultiBlockDefer, false)

EXPERIMENTAL_FEATURE(SE427NoInferenceOnExtension, true)


EXPERIMENTAL_FEATURE(Extern, true)

// Enable trailing comma for comma-separated lists.
EXPERIMENTAL_FEATURE(TrailingComma, false)

// Import bounds safety and lifetime attributes from interop headers to
// generate Swift wrappers with safe pointer types.
EXPERIMENTAL_FEATURE(SafeInteropWrappers, true)

/// Ignore resilience errors due to C++ types.
EXPERIMENTAL_FEATURE(AssumeResilientCxxTypes, true)

/// Import inherited non-public members when importing C++ classes.
EXPERIMENTAL_FEATURE(ImportNonPublicCxxMembers, true)

/// modify/read single-yield coroutines
SUPPRESSIBLE_EXPERIMENTAL_FEATURE(CoroutineAccessors, true)

/// modify/read single-yield coroutines always execute code post-yield code
EXPERIMENTAL_FEATURE(CoroutineAccessorsUnwindOnCallerError, false)

EXPERIMENTAL_FEATURE(AddressableParameters, true)
SUPPRESSIBLE_EXPERIMENTAL_FEATURE(AddressableTypes, true)

/// Allow custom availability domains to be defined and referenced.
EXPERIMENTAL_FEATURE(CustomAvailability, true)

/// Syntax sugar features for concurrency.
EXPERIMENTAL_FEATURE(ConcurrencySyntaxSugar, true)

/// Allow declaration of compile-time values
EXPERIMENTAL_FEATURE(CompileTimeValues, true)

/// Allow declaration of compile-time values
EXPERIMENTAL_FEATURE(CompileTimeValuesPreview, false)

/// Allow function body macros applied to closures.
EXPERIMENTAL_FEATURE(ClosureBodyMacro, true)

/// Allow declarations of Swift runtime symbols using @_silgen_name.
EXPERIMENTAL_FEATURE(AllowRuntimeSymbolDeclarations, true)

/// Allow use of `using` declaration that control default isolation
/// in a file scope.
EXPERIMENTAL_FEATURE(DefaultIsolationPerFile, false)

/// Enable @_lifetime attribute
SUPPRESSIBLE_EXPERIMENTAL_FEATURE(Lifetimes, true)

/// Excludes '(file)private' properties with initial values from the memberwise
/// initializer if there is a more accessible initializable property.
EXPERIMENTAL_FEATURE(ExcludePrivateFromMemberwiseInit, true)

/// Allow macro based aliases to be imported into Swift
EXPERIMENTAL_FEATURE(ImportMacroAliases, true)

/// Enable borrow/mutate accessors
EXPERIMENTAL_FEATURE(BorrowAndMutateAccessors, false)

/// Allow use of @inline(always) attribute
SUPPRESSIBLE_LANGUAGE_FEATURE(InlineAlways, 496, "@inline(always) attribute")

/// Allow use of 'Swift' (Swift runtime version) in @available attributes
EXPERIMENTAL_FEATURE(SwiftRuntimeAvailability, true)

/// 'Swift' availability is always standalone, even when targeting platforms
/// that have a built-in Swift runtime. Implies 'SwiftRuntimeAvailability'.
EXPERIMENTAL_FEATURE(StandaloneSwiftAvailability, true)

/// Allow use of `~Sendable`.
SUPPRESSIBLE_EXPERIMENTAL_FEATURE(TildeSendable, false)

/// Allow use of protocol typed values in Embedded mode (`Any` and friends)
EXPERIMENTAL_FEATURE(EmbeddedExistentials, true)

/// Allow use of the 'anyAppleOS' availability domain.
EXPERIMENTAL_FEATURE(AnyAppleOSAvailability, true)

/// Check @_implementationOnly imports in non-library-evolution mode.
EXPERIMENTAL_FEATURE(CheckImplementationOnly, true)

/// Extends CheckImplementationOnly with an extra check at serialization to
/// report references to implementation-only imported modules.
EXPERIMENTAL_FEATURE(CheckImplementationOnlyStrict, false)

/// Check that use sites have the required @_spi import for operators.
EXPERIMENTAL_FEATURE(EnforceSPIOperatorGroup, true)

#undef EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE
#undef EXPERIMENTAL_FEATURE
#undef UPCOMING_FEATURE
#undef MIGRATABLE_UPCOMING_FEATURE
#undef MIGRATABLE_EXPERIMENTAL_FEATURE
#undef MIGRATABLE_OPTIONAL_LANGUAGE_FEATURE
#undef BASELINE_LANGUAGE_FEATURE
#undef OPTIONAL_LANGUAGE_FEATURE
#undef CONDITIONALLY_SUPPRESSIBLE_EXPERIMENTAL_FEATURE
#undef CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE
#undef SUPPRESSIBLE_EXPERIMENTAL_FEATURE
#undef SUPPRESSIBLE_UPCOMING_FEATURE
#undef SUPPRESSIBLE_LANGUAGE_FEATURE
#undef LANGUAGE_FEATURE