//===--- Features.def - Swift Features Metaprogramming ----------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2021 - 2023 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.
//===----------------------------------------------------------------------===//

#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

#ifndef SUPPRESSIBLE_LANGUAGE_FEATURE
#  define SUPPRESSIBLE_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

#ifndef UPCOMING_FEATURE
#  define UPCOMING_FEATURE(FeatureName, SENumber, Version)   \
     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")
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")
LANGUAGE_FEATURE(BuiltinBuildTaskExecutorRef, 0, "TaskExecutor-building builtins")
BASELINE_LANGUAGE_FEATURE(BuiltinBuildExecutor, 0, "Executor-building builtins")
LANGUAGE_FEATURE(BuiltinBuildComplexEqualityExecutor, 0, "Executor-building for 'complexEquality executor' builtins")
BASELINE_LANGUAGE_FEATURE(BuiltinBuildMainExecutor, 0, "MainActor executor building builtin")
BASELINE_LANGUAGE_FEATURE(BuiltinCreateAsyncTaskInGroup, 0, "Task create in task group builtin with extra flags")
LANGUAGE_FEATURE(BuiltinCreateAsyncTaskInGroupWithExecutor, 0, "Task create in task group builtin with extra flags")
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")
LANGUAGE_FEATURE(BuiltinCreateAsyncDiscardingTaskInGroupWithExecutor, 0, "Task create in discarding task group with extra executor preference")
BASELINE_LANGUAGE_FEATURE(BuiltinCopy, 0, "Builtin.copy()")
BASELINE_LANGUAGE_FEATURE(BuiltinStackAlloc, 0, "Builtin.stackAlloc")
LANGUAGE_FEATURE(BuiltinUnprotectedStackAlloc, 0, "Builtin.unprotectedStackAlloc")
LANGUAGE_FEATURE(BuiltinAllocVector, 0, "Builtin.allocVector")
BASELINE_LANGUAGE_FEATURE(BuiltinTaskRunInline, 0, "Builtin.taskRunInline")
BASELINE_LANGUAGE_FEATURE(BuiltinUnprotectedAddressOf, 0, "Builtin.unprotectedAddressOf")
LANGUAGE_FEATURE(NewCxxMethodSafetyHeuristics, 0, "Only import C++ methods that return pointers (projections) on owned types as unsafe")
SUPPRESSIBLE_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")
SUPPRESSIBLE_LANGUAGE_FEATURE(PrimaryAssociatedTypes2, 346, "Primary associated types")
BASELINE_LANGUAGE_FEATURE(UnavailableFromAsync, 0, "@_unavailableFromAsync")
BASELINE_LANGUAGE_FEATURE(NoAsyncAvailability, 340, "@available(*, noasync)")
SUPPRESSIBLE_LANGUAGE_FEATURE(AssociatedTypeAvailability, 0, "Availability on associated types")
SUPPRESSIBLE_LANGUAGE_FEATURE(AsyncSequenceFailure, 0, "Failure associated type on AsyncSequence and AsyncIteratorProtocol")
BASELINE_LANGUAGE_FEATURE(BuiltinIntLiteralAccessors, 368, "Builtin.IntLiteral accessors")
LANGUAGE_FEATURE(Macros, 0, "Macros")
LANGUAGE_FEATURE(FreestandingExpressionMacros, 382, "Expression macros")
LANGUAGE_FEATURE(AttachedMacros, 389, "Attached macros")
LANGUAGE_FEATURE(ExtensionMacros, 402, "Extension macros")
LANGUAGE_FEATURE(MoveOnly, 390, "noncopyable types")
LANGUAGE_FEATURE(MoveOnlyResilientTypes, 390, "non-@frozen noncopyable types with library evolution")
LANGUAGE_FEATURE(ParameterPacks, 393, "Value and type parameter packs")
SUPPRESSIBLE_LANGUAGE_FEATURE(LexicalLifetimes, 0, "@_eagerMove/@_noEagerMove/@_lexicalLifetimes annotations")
LANGUAGE_FEATURE(FreestandingMacros, 397, "freestanding declaration macros")
SUPPRESSIBLE_LANGUAGE_FEATURE(RetroactiveAttribute, 364, "@retroactive")
SUPPRESSIBLE_LANGUAGE_FEATURE(ExtensionMacroAttr, 0, "@attached(extension)")
LANGUAGE_FEATURE(TypedThrows, 413, "Typed throws")
CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE(OptionalIsolatedParameters, 420, "Optional isolated parameters")
SUPPRESSIBLE_LANGUAGE_FEATURE(Extern, 0, "@_extern")
LANGUAGE_FEATURE(ExpressionMacroDefaultArguments, 422, "Expression macro as caller-side default argument")
LANGUAGE_FEATURE(BuiltinStoreRaw, 0, "Builtin.storeRaw")
LANGUAGE_FEATURE(BuiltinCreateTask, 0, "Builtin.createTask and Builtin.createDiscardingTask")
SUPPRESSIBLE_LANGUAGE_FEATURE(AssociatedTypeImplements, 0, "@_implements on associated types")
LANGUAGE_FEATURE(BuiltinAddressOfRawLayout, 0, "Builtin.addressOfRawLayout")
LANGUAGE_FEATURE(MoveOnlyPartialConsumption, 429, "Partial consumption of noncopyable values")

// 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)

// Swift 7
UPCOMING_FEATURE(ExistentialAny, 335, 7)
UPCOMING_FEATURE(InternalImportsByDefault, 409, 7)

EXPERIMENTAL_FEATURE(StaticAssert, false)
EXPERIMENTAL_FEATURE(NamedOpaqueTypes, false)
EXPERIMENTAL_FEATURE(FlowSensitiveConcurrencyCaptures, false)
EXPERIMENTAL_FEATURE(CodeItemMacros, false)
EXPERIMENTAL_FEATURE(BodyMacros, true)
EXPERIMENTAL_FEATURE(TupleConformances, false)
EXPERIMENTAL_FEATURE(FullTypedThrows, true)

// Whether to enable @_used and @_section attributes
EXPERIMENTAL_FEATURE(SymbolLinkageMarkers, 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(OneWayClosureParameters, false)
EXPERIMENTAL_FEATURE(LayoutPrespecialization, true)

EXPERIMENTAL_FEATURE(AccessLevelOnImport, 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)

/// Whether Objective-C completion handler parameters are imported as
/// @Sendable.
EXPERIMENTAL_FEATURE(SendableCompletionHandlers, 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 emit diagnostics from the new parser first, and only emit
/// diagnostics from the existing parser when there are none from the new
/// parser.
EXPERIMENTAL_FEATURE(ParserDiagnostics, 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)

/// Import C++ class templates as semantically-meaningless symbolic
/// Swift types and C++ methods as symbolic functions with blank
/// signatures.
EXPERIMENTAL_FEATURE(ImportSymbolicCXXDecls, 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 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)

/// Enables noncopyable generics
SUPPRESSIBLE_EXPERIMENTAL_FEATURE(NoncopyableGenerics, true)

// Alias for NoncopyableGenerics
EXPERIMENTAL_FEATURE(NoncopyableGenerics2, true)

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

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

/// Enable non-escapable type attributes and function attributes that support
/// lifetime-dependent results.
EXPERIMENTAL_FEATURE(NonescapableTypes, true)

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

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

/// Enable bitwise-copyable feature.
EXPERIMENTAL_FEATURE(BitwiseCopyable, true)

/// Enable the suppression of inferred, non-invertible, protocols via ~.
SUPPRESSIBLE_EXPERIMENTAL_FEATURE(ConformanceSuppression, true)

/// Enables the FixedArray data type.
EXPERIMENTAL_FEATURE(FixedArrays, true)

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

// Allow for the 'transferring' keyword to be applied to arguments and results.
EXPERIMENTAL_FEATURE(TransferringArgsAndResults, true)

// Allow for `switch` of noncopyable values to be borrowing or consuming.
EXPERIMENTAL_FEATURE(BorrowingSwitch, true)

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

// Enable isolated(any) attribute on function types.
CONDITIONALLY_SUPPRESSIBLE_EXPERIMENTAL_FEATURE(IsolatedAny, true)

// Whether lookup of members respects the enclosing file's imports.
EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE(MemberImportVisibility, true)

// Alias for IsolatedAny
EXPERIMENTAL_FEATURE(IsolatedAny2, true)

// Enable usability improvements for global-actor-isolated types.
EXPERIMENTAL_FEATURE(GlobalActorIsolatedTypesUsability, true)

// Enable @implementation on extensions of ObjC classes.
EXPERIMENTAL_FEATURE(ObjCImplementation, true)

// Enable @implementation on @_cdecl functions.
EXPERIMENTAL_FEATURE(CImplementation, true)

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

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

#undef EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE
#undef EXPERIMENTAL_FEATURE
#undef UPCOMING_FEATURE
#undef BASELINE_LANGUAGE_FEATURE
#undef CONDITIONALLY_SUPPRESSIBLE_EXPERIMENTAL_FEATURE
#undef CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE
#undef SUPPRESSIBLE_EXPERIMENTAL_FEATURE
#undef SUPPRESSIBLE_LANGUAGE_FEATURE
#undef LANGUAGE_FEATURE