[SR-8180] Migrator inserts unresolvable type RawValue when migrating to new enums

[ChristopherRogers]

Previous ID	SR-8180
Radar	rdar://problem/44582517
Original Reporter	@ChristopherRogers
Type	Bug

Attachment: Download

Environment

Xcode 10.0 beta 3 (10L201y)

Additional Detail from JIRA

Votes	0
Component/s	Source Tooling
Labels	Bug, Migrator
Assignee	None
Priority	Medium

md5: 7deb6a8b2a22152df317be5955d289b5

Issue Description:

Migrating this Swift 4.0 code to 4.2 results in the following build errors. (The resulting code is commented out.)

import UIKit

var window: UIWindow?

func foo() {
    // error: use of unresolved identifier 'RawValue'
    // window!.windowLevel = UIWindow.Level(rawValue: RawValue(Int(window!.windowLevel.rawValue) + 1))
    window!.windowLevel = window!.windowLevel + 1

    let view = UIView()
    let isSelected = true
    // error: use of unresolved identifier 'RawValue'
    // view.accessibilityTraits = isSelected ? UIAccessibilityTraits(rawValue: RawValue(UInt8(UIAccessibilityTraits.button.rawValue) | UInt8(UIAccessibilityTraits.selected.rawValue))) : UIAccessibilityTraits.button
    view.accessibilityTraits = isSelected ? UIAccessibilityTraitButton | UIAccessibilityTraitSelected : UIAccessibilityTraitButton
}

[belkadan]

cc @nkcsgexi

[keith]

I think the ideal migration for this would actually result in something like:

view.accessibilityTraits = isSelected ? UIAccessibilityTraits.button.union(.selected) : .button

This might be unreasonable for the migrator, but the rawValue dances being done here aren't necessary.

[swift-ci]

Comment by John Montgomery (JIRA)

First example at least is still present in the release version. My previous code was

window.windowLevel = (UIApplication.shared.windows.last?.windowLevel ?? 0) + 1

and it tried to convert it to

window.windowLevel = (UIApplication.shared.windows.last?.windowLevel ?? UIWindow.Level(rawValue: RawValue(0))) + 1

[belkadan]

@swift-ci create

[nkcsgexi]

@ChristopherRogers I cannot reproduce the `RawValue()` insertion in my Xcode migrator. Could you try if this issue still reproduces in Xcode 10.1 beta? if so, could you share the codebase for us to investigate?