test/Interpreter/SDK/autorelease.swift

// RUN: %target-run-simple-swift | %FileCheck %s
// REQUIRES: executable_test

// REQUIRES: objc_interop

// The Objective-C runtime does not implement the autorelease
// optimization on i386, even in the iOS simulator.
// XFAIL: CPU=i386

import Foundation

class PrintOnDeinit: NSObject {
  // Result should get autoreleased.
  @objc dynamic class func create() -> PrintOnDeinit {
    return PrintOnDeinit()
  }

  deinit { print("object died") }
}
func useTemp() {
  let f = PrintOnDeinit.create()
}

// objc_retainAutoreleasedReturnValue will fail to reclaim the first
// object autoreleased from each shared object on x86_64, so prime it.
autoreleasepool { useTemp() }
autoreleasepool {
  print("autorelease test begin")
  useTemp()
  print("after call to useTemp")
}
print("autorelease test end")
// CHECK:      autorelease test begin
// CHECK-NEXT: object died
// CHECK-NEXT: after call to useTemp
// CHECK-NEXT: autorelease test end

// Using an @objc class to check that errors are retained across the pool
// boundaries. A classic crash is an error created inside a pool and then
// zombied before handling it outside the pool.
@objc class MyError : NSObject, Error {
  let message: String
  init(message: String) {
    self.message = message
  }
}

// Check that rethrow works.
func requireString(string: String?) throws -> String {
  guard let string = string else {
    throw MyError(message: "no string")
  }
  print("returning \"\(string)\"")
  return string
}
do {
  try autoreleasepool {
    try requireString(string: "ok")
    try requireString(string: nil)
  }
} catch let err as MyError {
  print("caught \"\(err.message)\"")
}
// CHECK-NEXT:      returning "ok"
// CHECK-NEXT:      caught "no string"

// Check that a return value can be passed back.
let result = try autoreleasepool {
  return "a string"
}
print("result = \"\(result)\"")
// CHECK-NEXT:      result = "a string"