unowned.swift

import Foundation

func f() {
    unowned var unownedValue: NSDate?
    unownedValue = NSDate()
}

unowned_SIL.txt

sil_stage canonical

import Builtin
import Swift
import SwiftShims

import Foundation

func f()

// main
sil @main : $@convention(c) (Int32, UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>) -> Int32 {
bb0(%0 : $Int32, %1 : $UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>):
  %2 = integer_literal $Builtin.Int32, 0          // user: %3
  %3 = struct $Int32 (%2 : $Builtin.Int32)        // user: %4
  return %3 : $Int32                              // id: %4
} // end sil function 'main'

// f()
sil hidden @$s5test11fyyF : $@convention(thin) () -> () {
bb0:
  %0 = alloc_stack $@sil_unowned Optional<NSDate>, var, name "unownedValue" // users: %13, %12, %3, %8
  %1 = metatype $@thin Optional<NSDate>.Type
  %2 = enum $Optional<NSDate>, #Optional.none!enumelt // user: %3
  store_unowned %2 to [initialization] %0 : $*@sil_unowned Optional<NSDate> // id: %3
  %4 = metatype $@thick NSDate.Type               // user: %6
  // function_ref NSDate.__allocating_init()
  %5 = function_ref @$sSo6NSDateCABycfC : $@convention(method) (@thick NSDate.Type) -> @owned NSDate // user: %6
  %6 = apply %5(%4) : $@convention(method) (@thick NSDate.Type) -> @owned NSDate // user: %7
  %7 = unchecked_ref_cast %6 : $NSDate to $Optional<NSDate> // users: %10, %9
  %8 = begin_access [modify] [static] %0 : $*@sil_unowned Optional<NSDate> // users: %11, %9
  store_unowned %7 to %8 : $*@sil_unowned Optional<NSDate> // id: %9
  release_value %7 : $Optional<NSDate>            // id: %10
  end_access %8 : $*@sil_unowned Optional<NSDate> // id: %11
  destroy_addr %0 : $*@sil_unowned Optional<NSDate> // id: %12
  dealloc_stack %0 : $*@sil_unowned Optional<NSDate> // id: %13
  %14 = tuple ()                                  // user: %15
  return %14 : $()                                // id: %15
} // end sil function '$s5test11fyyF'

// NSDate.__allocating_init()
sil shared [serializable] @$sSo6NSDateCABycfC : $@convention(method) (@thick NSDate.Type) -> @owned NSDate {
// %0                                             // user: %1
bb0(%0 : $@thick NSDate.Type):
  %1 = thick_to_objc_metatype %0 : $@thick NSDate.Type to $@objc_metatype NSDate.Type // user: %2
  %2 = alloc_ref_dynamic [objc] %1 : $@objc_metatype NSDate.Type, $NSDate // user: %4
  // function_ref @nonobjc NSDate.init()
  %3 = function_ref @$sSo6NSDateCABycfcTO : $@convention(method) (@owned NSDate) -> @owned NSDate // user: %4
  %4 = apply %3(%2) : $@convention(method) (@owned NSDate) -> @owned NSDate // user: %5
  return %4 : $NSDate                             // id: %5
} // end sil function '$sSo6NSDateCABycfC'

// @nonobjc NSDate.init()
sil shared [serializable] [thunk] @$sSo6NSDateCABycfcTO : $@convention(method) (@owned NSDate) -> @owned NSDate {
// %0                                             // users: %2, %1
bb0(%0 : $NSDate):
  %1 = objc_method %0 : $NSDate, #NSDate.init!initializer.1.foreign : (NSDate.Type) -> () -> NSDate, $@convention(objc_method) (@owned NSDate) -> @owned NSDate // user: %2
  %2 = apply %1(%0) : $@convention(objc_method) (@owned NSDate) -> @owned NSDate // user: %3
  return %2 : $NSDate                             // id: %3
} // end sil function '$sSo6NSDateCABycfcTO'

weak.swift

import Foundation

func f() {
    weak var weakValue: NSDate?
    weakValue = NSDate()
}

weak_SIL.txt

sil_stage canonical

import Builtin
import Swift
import SwiftShims

import Foundation

func f() -> NSDate

// main
sil @main : $@convention(c) (Int32, UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>) -> Int32 {
bb0(%0 : $Int32, %1 : $UnsafeMutablePointer<Optional<UnsafeMutablePointer<Int8>>>):
  %2 = integer_literal $Builtin.Int32, 0          // user: %3
  %3 = struct $Int32 (%2 : $Builtin.Int32)        // user: %4
  return %3 : $Int32                              // id: %4
} // end sil function 'main'

// f()
sil hidden @$s5test21fSo6NSDateCyF : $@convention(thin) () -> @owned NSDate {
bb0:
  %0 = alloc_stack $@sil_unowned Optional<NSDate>, var, name "unownedValue" // users: %27, %26, %3
  %1 = metatype $@thin Optional<NSDate>.Type
  %2 = enum $Optional<NSDate>, #Optional.none!enumelt // user: %3
  store_unowned %2 to [initialization] %0 : $*@sil_unowned Optional<NSDate> // id: %3
  %4 = alloc_stack $@sil_weak Optional<NSDate>, var, name "weakValue" // users: %25, %24, %7, %18
  %5 = metatype $@thin Optional<NSDate>.Type
  %6 = enum $Optional<NSDate>, #Optional.none!enumelt // user: %7
  store_weak %6 to [initialization] %4 : $*@sil_weak Optional<NSDate> // id: %7
  %8 = alloc_stack $Optional<NSDate>, var, name "strongValue" // users: %11, %23, %22
  %9 = metatype $@thin Optional<NSDate>.Type
  %10 = enum $Optional<NSDate>, #Optional.none!enumelt // user: %11
  store %10 to %8 : $*Optional<NSDate>            // id: %11
  %12 = metatype $@thick NSDate.Type              // user: %14
  // function_ref NSDate.__allocating_init()
  %13 = function_ref @$sSo6NSDateCABycfC : $@convention(method) (@thick NSDate.Type) -> @owned NSDate // user: %14
  %14 = apply %13(%12) : $@convention(method) (@thick NSDate.Type) -> @owned NSDate // users: %28, %17, %16, %15
  debug_value %14 : $NSDate, let, name "nsDate"   // id: %15
  strong_retain %14 : $NSDate                     // id: %16
  %17 = enum $Optional<NSDate>, #Optional.some!enumelt.1, %14 : $NSDate // users: %20, %19
  %18 = begin_access [modify] [static] %4 : $*@sil_weak Optional<NSDate> // users: %21, %19
  store_weak %17 to %18 : $*@sil_weak Optional<NSDate> // id: %19
  release_value %17 : $Optional<NSDate>           // id: %20
  end_access %18 : $*@sil_weak Optional<NSDate>   // id: %21
  destroy_addr %8 : $*Optional<NSDate>            // id: %22
  dealloc_stack %8 : $*Optional<NSDate>           // id: %23
  destroy_addr %4 : $*@sil_weak Optional<NSDate>  // id: %24
  dealloc_stack %4 : $*@sil_weak Optional<NSDate> // id: %25
  destroy_addr %0 : $*@sil_unowned Optional<NSDate> // id: %26
  dealloc_stack %0 : $*@sil_unowned Optional<NSDate> // id: %27
  return %14 : $NSDate                            // id: %28
} // end sil function '$s5test21fSo6NSDateCyF'

// NSDate.__allocating_init()
sil shared [serializable] @$sSo6NSDateCABycfC : $@convention(method) (@thick NSDate.Type) -> @owned NSDate {
// %0                                             // user: %1
bb0(%0 : $@thick NSDate.Type):
  %1 = thick_to_objc_metatype %0 : $@thick NSDate.Type to $@objc_metatype NSDate.Type // user: %2
  %2 = alloc_ref_dynamic [objc] %1 : $@objc_metatype NSDate.Type, $NSDate // user: %4
  // function_ref @nonobjc NSDate.init()
  %3 = function_ref @$sSo6NSDateCABycfcTO : $@convention(method) (@owned NSDate) -> @owned NSDate // user: %4
  %4 = apply %3(%2) : $@convention(method) (@owned NSDate) -> @owned NSDate // user: %5
  return %4 : $NSDate                             // id: %5
} // end sil function '$sSo6NSDateCABycfC'

// @nonobjc NSDate.init()
sil shared [serializable] [thunk] @$sSo6NSDateCABycfcTO : $@convention(method) (@owned NSDate) -> @owned NSDate {
// %0                                             // users: %2, %1
bb0(%0 : $NSDate):
  %1 = objc_method %0 : $NSDate, #NSDate.init!initializer.1.foreign : (NSDate.Type) -> () -> NSDate, $@convention(objc_method) (@owned NSDate) -> @owned NSDate // user: %2
  %2 = apply %1(%0) : $@convention(objc_method) (@owned NSDate) -> @owned NSDate // user: %3
  return %2 : $NSDate                             // id: %3
} // end sil function '$sSo6NSDateCABycfcTO'