// RUN: %target-swift-frontend -emit-ir %s

// This is a compile-only test. It checks if IRGen does not crash when packing
// and unpacking enums (e.g. optionals) which contain empty structs as payloads.

sil_stage canonical

import Builtin
import Swift

public struct ECurve {

    public func point () -> ECPoint?
}

public struct ECPoint {
    public let curve: ECurve

    public var coordinate: Int32

    init(curve: ECurve)
}

func unpack(ec : ECPoint?) -> ECPoint

// top_level_code
sil private @top_level_code : $@convention(thin) () -> () {
bb0:
  %0 = tuple ()                                   // user: %1
  return %0 : $()                                 // id: %1
}

// ECurve.ECurve.point (ECurve.ECurve)() -> Swift.Optional<ECurve.ECPoint>
sil @_TFV6ECurve6ECurve5pointfS0_FT_GSqVS_7ECPoint_ : $@convention(method) (ECurve) -> Optional<ECPoint> {
bb0(%0 : $ECurve):
  %1 = integer_literal $Builtin.Int32, 9          // user: %2
  %2 = struct $Int32 (%1 : $Builtin.Int32)        // user: %4
  %3 = struct $ECurve ()                          // user: %4
  %4 = struct $ECPoint (%3 : $ECurve, %2 : $Int32) // user: %5
  %5 = enum $Optional<ECPoint>, #Optional.some!enumelt.1, %4 : $ECPoint // user: %6
  return %5 : $Optional<ECPoint>                  // id: %6
}

// ECurve.unpack (Swift.Optional<ECurve.ECPoint>) -> ECurve.ECPoint
sil @_TF6ECurve6unpackFGSqVS_7ECPoint_S0_ : $@convention(thin) (Optional<ECPoint>) -> ECPoint {
bb0(%0 : $Optional<ECPoint>):
  switch_enum %0 : $Optional<ECPoint>, case #Optional.some!enumelt.1: bb1, case #Optional.none!enumelt: bb2 // id: %1

bb1:                                              // Preds: bb0
  %2 = unchecked_enum_data %0 : $Optional<ECPoint>, #Optional.some!enumelt.1 // user: %3
  return %2 : $ECPoint                            // id: %3

bb2:                                              // Preds: bb0
  %4 = integer_literal $Builtin.Int1, -1          // user: %5
  cond_fail %4 : $Builtin.Int1                    // id: %5
  unreachable                                     // id: %6
}