async_fib.swift

// RUN: %empty-directory(%t)
// RUN: %target-build-swift -target %target-swift-5.1-abi-triple %s -parse-as-library -module-name main -o %t/main
// RUN: %target-codesign %t/main
// RUN: %target-run %t/main | %FileCheck %s

// REQUIRES: concurrency
// REQUIRES: executable_test
// REQUIRES: concurrency_runtime
// UNSUPPORTED: back_deployment_runtime
// UNSUPPORTED: OS=windows-msvc

vargg=0

@inline(never)
publicfunc identity<T>(_ x:T)->T{
 gg +=1
return x
}

actorActor{
varx:Int=0
init(x:Int){self.x = x }

@inline(never)
func get(_ i:Int)async->Int{
return i + x
}
}

// Used to crash with an stack overflow with m >= 18
letm=22

@inline(never)
func asyncFib(_ n:Int, _ a1:Actor, _ a2:Actor)async->Int{
if n ==0{
returnawait a1.get(n)
}
if n ==1{
returnawait a2.get(n)
}

letfirst=awaitasyncFib(n-2, a1, a2)
letsecond=awaitasyncFib(n-1, a1, a2)

letresult= first + second

return result
}

@mainstructMain{
staticfunc main()async{
leta1=Actor(x:0)
leta2=Actor(x:0)
 _ =awaitasyncFib(identity(m), a1, a2)

 // CHECK: result: 0
awaitprint("result: \(a1.x)");
awaitprint(a2.x)
}
}