[SR-11374] crash in libswiftCore.dylib`swift::gatherWrittenGenericArgs:

[swift-ci]

Previous ID	SR-11374
Radar	rdar://problem/54775582
Original Reporter	miku1958 (JIRA User)
Type	Bug
Status	Resolved
Resolution	Done

Attachment: Download

Environment

Xcode 10 and Xcode 11 beta6 all have this issue

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug, RunTimeCrash, Runtime
Assignee	None
Priority	Medium

md5: 1136ea0efdd0cba4ea7dc556fa2a083c

Issue Description:

I try to write code like this:

extension UIView

{ class _Delegate<View> where View: UIView { }

}

extension UITextView

{ class Delegate: UIView._Delegate1<UITextView> { }

}

and it work fine when these two extension in the same file,

but once I move one of them into an new file, it crash in:

type metadata accessor for UITextView.Delegate:
libswiftCore.dylib`swift::gatherWrittenGenericArgs:

when I init a UITextView.Delegate object.

You can try these code in sample Xcode project. I am not sure is it Xcode bug or swift bug

[swift-ci]

Comment by 庄黛淳华 (JIRA)

I just try something, Delegate is not necessary to declared in other Type, but it's necessary to declared the _Delegate in other Type and using Generics

[belkadan]

Reproduced in Xcode 11b6 compiling for the simulator. Looks like some of the other bugs we have with generics in the runtime. Thanks for reporting!

@swift-ci create

[DougGregor]

Fixed by #26936