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// RUN: %target-typecheck-verify-swift -swift-version 4
@escaping var fn : () -> Int = { 4 } // expected-error {{attribute can only be applied to types, not declarations}}
func paramDeclEscaping(@escaping fn: (Int) -> Void) {} // expected-error {{attribute can only be applied to types, not declarations}}
func wrongParamType(a: @escaping Int) {} // expected-error {{@escaping attribute only applies to function types}}
func conflictingAttrs(_ fn: @noescape @escaping () -> Int) {} // expected-error {{unknown attribute 'noescape'}}
func takesEscaping(_ fn: @escaping () -> Int) {} // ok
func callEscapingWithNoEscape(_ fn: () -> Int) {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{37-37=@escaping }}
takesEscaping(fn) // expected-error{{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
// This is a non-escaping use:
let _ = fn
}
typealias IntSugar = Int
func callSugared(_ fn: () -> IntSugar) {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{24-24=@escaping }}
takesEscaping(fn) // expected-error{{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
struct StoresClosure {
var closure : () -> Int
init(_ fn: () -> Int) {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{14-14=@escaping }}
closure = fn // expected-error{{assigning non-escaping parameter 'fn' to an @escaping closure}}
}
func arrayPack(_ fn: () -> Int) -> [() -> Int] {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{24-24=@escaping }}
return [fn] // expected-error{{using non-escaping parameter 'fn' in a context expecting an @escaping closure}}
}
func dictPack(_ fn: () -> Int) -> [String: () -> Int] {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{23-23=@escaping }}
return ["ultimate answer": fn] // expected-error{{using non-escaping parameter 'fn' in a context expecting an @escaping closure}}
}
func autoclosureDictPack(_ fn: @autoclosure () -> Int) -> [String: () -> Int] {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{46-46= @escaping}}
return ["ultimate answer": fn] // expected-error{{using non-escaping parameter 'fn' in a context expecting an @escaping closure}}
}
func arrayPack(_ fn: @escaping () -> Int, _ fn2 : () -> Int) -> [() -> Int] {
// expected-note@-1{{parameter 'fn2' is implicitly non-escaping}} {{53-53=@escaping }}
return [fn, fn2] // expected-error{{using non-escaping parameter 'fn2' in a context expecting an @escaping closure}}
}
}
func takesEscapingBlock(_ fn: @escaping @convention(block) () -> Void) {
fn()
}
func callEscapingWithNoEscapeBlock(_ fn: () -> Void) {
// expected-note@-1{{parameter 'fn' is implicitly non-escaping}} {{42-42=@escaping }}
takesEscapingBlock(fn) // expected-error{{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
func takesEscapingAutoclosure(_ fn: @autoclosure @escaping () -> Int) {}
func callEscapingAutoclosureWithNoEscape(_ fn: () -> Int) {
takesEscapingAutoclosure(1+1)
}
let foo: @escaping (Int) -> Int // expected-error{{@escaping attribute may only be used in function parameter position}} {{10-20=}}
struct GenericStruct<T> {}
func misuseEscaping(_ a: @escaping Int) {} // expected-error{{@escaping attribute only applies to function types}} {{26-36=}}
func misuseEscaping(_ a: (@escaping Int)?) {} // expected-error{{@escaping attribute only applies to function types}} {{27-36=}}
func misuseEscaping(opt a: @escaping ((Int) -> Int)?) {} // expected-error{{closure is already escaping in optional type argument}} {{28-38=}}
func misuseEscaping(_ a: (@escaping (Int) -> Int)?) {} // expected-error{{closure is already escaping in optional type argument}} {{27-36=}}
func misuseEscaping(nest a: (((@escaping (Int) -> Int))?)) {} // expected-error{{closure is already escaping in optional type argument}} {{32-41=}}
func misuseEscaping(iuo a: (@escaping (Int) -> Int)!) {} // expected-error{{closure is already escaping in optional type argument}} {{29-38=}}
func misuseEscaping(_ a: Optional<@escaping (Int) -> Int>, _ b: Int) {} // expected-error{{@escaping attribute may only be used in function parameter position}} {{35-44=}}
func misuseEscaping(_ a: (@escaping (Int) -> Int, Int)) {} // expected-error{{@escaping attribute may only be used in function parameter position}} {{27-36=}}
func misuseEscaping(_ a: [@escaping (Int) -> Int]) {} // expected-error{{@escaping attribute may only be used in function parameter position}} {{27-36=}}
func misuseEscaping(_ a: [@escaping (Int) -> Int]?) {} // expected-error{{@escaping attribute may only be used in function parameter position}} {{27-36=}}
func misuseEscaping(_ a: [Int : @escaping (Int) -> Int]) {} // expected-error{{@escaping attribute may only be used in function parameter position}} {{33-43=}}
func misuseEscaping(_ a: GenericStruct<@escaping (Int) -> Int>) {} // expected-error{{@escaping attribute may only be used in function parameter position}} {{40-49=}}
func takesEscapingGeneric<T>(_ fn: @escaping () -> T) {}
func callEscapingGeneric<T>(_ fn: () -> T) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{35-35=@escaping }}
takesEscapingGeneric(fn) // expected-error {{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
class Super {}
class Sub: Super {}
func takesEscapingSuper(_ fn: @escaping () -> Super) {}
func callEscapingSuper(_ fn: () -> Sub) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{30-30=@escaping }}
takesEscapingSuper(fn) // expected-error {{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
func takesEscapingSuperGeneric<T: Super>(_ fn: @escaping () -> T) {}
func callEscapingSuperGeneric(_ fn: () -> Sub) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{37-37=@escaping }}
takesEscapingSuperGeneric(fn) // expected-error {{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
func callEscapingSuperGeneric<T: Sub>(_ fn: () -> T) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{45-45=@escaping }}
takesEscapingSuperGeneric(fn) // expected-error {{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
func testModuloOptionalness() {
var iuoClosure: (() -> Void)! = nil
func setIUOClosure(_ fn: () -> Void) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{28-28=@escaping }}
iuoClosure = fn // expected-error{{assigning non-escaping parameter 'fn' to an @escaping closure}}
}
var iuoClosureExplicit: (() -> Void)!
func setExplicitIUOClosure(_ fn: () -> Void) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{36-36=@escaping }}
iuoClosureExplicit = fn // expected-error{{assigning non-escaping parameter 'fn' to an @escaping closure}}
}
var deepOptionalClosure: (() -> Void)???
func setDeepOptionalClosure(_ fn: () -> Void) { // expected-note {{parameter 'fn' is implicitly non-escaping}} {{37-37=@escaping }}
deepOptionalClosure = fn // expected-error{{assigning non-escaping parameter 'fn' to an @escaping closure}}
}
}
// Check that functions in vararg position are @escaping
func takesEscapingFunction(fn: @escaping () -> ()) {}
func takesArrayOfFunctions(array: [() -> ()]) {}
func takesVarargsOfFunctions(fns: () -> ()...) {
takesArrayOfFunctions(array: fns)
for fn in fns {
takesEscapingFunction(fn: fn)
}
}
func takesVarargsOfFunctionsExplicitEscaping(fns: @escaping () -> ()...) {} // expected-error{{@escaping attribute may only be used in function parameter position}}
func takesNoEscapeFunction(fn: () -> ()) { // expected-note {{parameter 'fn' is implicitly non-escaping}}
takesVarargsOfFunctions(fns: fn) // expected-error {{passing non-escaping parameter 'fn' to function expecting an @escaping closure}}
}
class FooClass {
var stored : Optional<(()->Int)->Void> = nil // expected-note {{add explicit @escaping to function parameter #0}} {{26-26=@escaping }}
var computed : (()->Int)->Void {
get { return stored! }
set(newValue) { stored = newValue } // ok
}
var computedEscaping : (@escaping ()->Int)->Void {
get { return stored! }
set(newValue) { stored = newValue } // expected-error{{cannot assign value of type '(@escaping () -> Int) -> Void' to type '(() -> Int) -> Void'}}
// expected-note@-1{{parameter #0 expects escaping value of type '() -> Int'}}
}
}
// A call of a closure literal should be non-escaping
func takesInOut(y: inout Int) {
_ = {
y += 1 // no-error
}()
_ = ({
y += 1 // no-error
})()
_ = { () in
y += 1 // no-error
}()
_ = ({ () in
y += 1 // no-error
})()
_ = { () -> () in
y += 1 // no-error
}()
_ = ({ () -> () in
y += 1 // no-error
})()
}
class HasIVarCaptures {
var x: Int = 0
func method() {
_ = {
x += 1 // no-error
}()
_ = ({
x += 1 // no-error
})()
_ = { () in
x += 1 // no-error
}()
_ = ({ () in
x += 1 // no-error
})()
_ = { () -> () in
x += 1 // no-error
}()
_ = ({ () -> () in
x += 1 // no-error
})()
}
}
// https://github.com/apple/swift/issues/52188
protocol P_52188 {
typealias F = () -> Void
typealias G<T> = (T) -> Void
func foo<T>(_: T, _: @escaping F) // Ok
func bar<T>(_: @escaping G<T>) // Ok
}
extension P_52188 {
func fiz<T>(_: T, _: @escaping F) {} // Ok
func baz<T>(_: @escaping G<T>) {} // Ok
}
// https://github.com/apple/swift/issues/51669
func f_51669<T>(_ x: @escaping T) {} // expected-error 1{{@escaping attribute only applies to function types}}
// https://github.com/apple/swift/issues/57070
var global: ((() -> Void) -> Void)? = nil
// expected-note@-1 {{add explicit @escaping to function parameter #0}} {{15-15=@escaping }}
class C_57070 {
let ok: (@escaping () -> Void) -> Void // OK
let callback: (() -> Void) -> Void // expected-note {{add explicit @escaping to function parameter #0}} {{18-18=@escaping }}
let callback1: (() -> Void, () -> Void) -> Void // expected-note {{add explicit @escaping to function parameter #1}} {{31-31=@escaping }}
let callbackAuto: (@autoclosure () -> Void) -> Void // expected-note {{add explicit @escaping to function parameter #0}} {{34-34= @escaping}}
let callbackOpt: ((() -> Void) -> Void)? // expected-note{{add explicit @escaping to function parameter #0}} {{22-22=@escaping }}
init(f: @escaping (@escaping() -> Void) -> Void) {
self.callback = f // expected-error{{cannot assign value of type '(@escaping () -> Void) -> Void' to type '(() -> Void) -> Void'}}
// expected-note@-1{{parameter #0 expects escaping value of type '() -> Void'}}
self.ok = f // Ok
}
init(af: @escaping (@escaping() -> Void) -> Void) {
self.callbackOpt = af // expected-error{{cannot assign value of type '(@escaping () -> Void) -> Void' to type '(() -> Void) -> Void'}}
// expected-note@-1{{parameter #0 expects escaping value of type '() -> Void'}}
}
init(ag: @escaping (@escaping() -> Void) -> Void) {
global = ag // expected-error{{cannot assign value of type '(@escaping () -> Void) -> Void' to type '(() -> Void) -> Void'}}
// expected-note@-1{{parameter #0 expects escaping value of type '() -> Void'}}
}
init(a: @escaping (@escaping () -> Void) -> Void) {
self.callbackAuto = a // expected-error{{cannot assign value of type '(@escaping () -> Void) -> Void' to type '(@autoclosure () -> Void) -> Void'}}
// expected-note@-1{{parameter #0 expects escaping value of type '() -> Void'}}
}
init(f: @escaping (() -> Void, @escaping() -> Void) -> Void) {
self.callback1 = f // expected-error{{cannot assign value of type '(() -> Void, @escaping () -> Void) -> Void' to type '(() -> Void, () -> Void) -> Void'}}
// expected-note@-1{{parameter #1 expects escaping value of type '() -> Void'}}
}
}
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