unavailable.swift

// RUN: %target-typecheck-verify-swift -swift-version 4 -enable-objc-interop

// An @objc protocol can have 'unavailable'
// methods.  They are treated as if they
// were marked optional
@objc protocol Proto {
  @objc @available(*,unavailable) optional func bad()
  func good()
}

class Foo : Proto {
  @objc func good() {}
}

// Reject protocols with 'unavailable' requirements
// if a protocol is not marked @objc.
protocol NonObjCProto {
  @available(*,unavailable) // expected-error {{protocol members can only be marked unavailable in an @objc protocol}}
  func bad() // expected-note {{protocol requires function 'bad()'}}

  func good()

  @_spi_available(macOS, introduced: 10.9) // expected-warning {{protocol members can only be marked unavailable in an @objc protocol}}
  func kindaBad() // expected-note {{protocol requires function 'kindaBad()'}}
}

class Bar : NonObjCProto { // expected-error {{type 'Bar' does not conform to protocol 'NonObjCProto'}} expected-note {{add stubs for conformance}}
  func good() {}
}


// Complain about unavailable witnesses (error in Swift 4, warning in Swift 3)
protocol P {
  func foo(bar: Foo) // expected-note 3 {{requirement 'foo(bar:)' declared here}}
}

struct ConformsToP : P { // expected-error{{type 'ConformsToP' does not conform to protocol 'P'}}
  @available(*, unavailable)
  func foo(bar: Foo) { } // expected-error{{unavailable instance method 'foo(bar:)' was used to satisfy a requirement of protocol 'P'}}
}

struct ConformsToP2 {
  @available(*, unavailable)
  func foo(bar: Foo) { } // expected-note {{'foo(bar:)' declared here}}
}
extension ConformsToP2: P {} // expected-error{{type 'ConformsToP2' does not conform to protocol 'P'}}
// expected-error@-1 {{unavailable instance method 'foo(bar:)' was used to satisfy a requirement of protocol 'P'}}

@available(*, unavailable)
struct ConformsToP3: P {
  func foo(bar: Foo) { }
}

// Ok, an unavailable decl should be allowed to witness a requirement when the
// conforming type is itself unavailable.
@available(*, unavailable)
struct ConformsToP4: P {
  @available(*, unavailable)
  func foo(bar: Foo) { }
}

struct ConformsToP5 {}

// Ok, an unavailable decl should be allowed to witness a requirement when the
// conformance extension is itself unavailable.
@available(*, unavailable)
extension ConformsToP5: P {
  @available(*, unavailable)
  func foo(bar: Foo) { }
}

struct ConformsToP6: P {} // expected-error{{type 'ConformsToP6' does not conform to protocol 'P'}}
// expected-error@-1 {{unavailable instance method 'foo(bar:)' was used to satisfy a requirement of protocol 'P'}}

@available(*, unavailable)
extension ConformsToP6 {
  func foo(bar: Foo) { } // expected-note {{'foo(bar:)' declared here}}
}

@available(*, unavailable)
enum UnavailableEnum {
  struct ConformsToP6: P {
    @available(*, unavailable)
    func foo(bar: Foo) { }
  }
}

// Include message string from @available attribute if provided
protocol Unavail {
  associatedtype T
  func req() // expected-note {{requirement 'req()' declared here}}
}
extension Unavail {
  func req() {}
}
extension Unavail where T == Self {
  @available(*, unavailable, message: "write it yourself") func req() {} // expected-note {{'req()' declared here}}
}

struct NonSelfT: Unavail {
  typealias T = Int
}
struct SelfT: Unavail { // expected-error {{type 'SelfT' does not conform to protocol 'Unavail'}}
  // expected-error@-1 {{unavailable instance method 'req()' was used to satisfy a requirement of protocol 'Unavail': write it yourself}}
  typealias T = SelfT
}

protocol UnavailableAssoc {
  @available(*, unavailable) // expected-error {{associated type cannot be marked unavailable with '@available'}}
  associatedtype A1

  @available(swift, introduced: 4)
  associatedtype A2

  @available(swift, introduced: 99) // expected-error {{associated type cannot be marked unavailable with '@available'}}
  associatedtype A3

  @available(swift, obsoleted: 4) // expected-error {{associated type cannot be marked unavailable with '@available'}}
  associatedtype A4

  @available(swift, obsoleted: 99)
  associatedtype A5

  @_spi_available(macOS, introduced: 11) // expected-error {{associated type cannot be marked unavailable with '@available'}}
  associatedtype A6
}