Open Radar

 
Area:
Xcode

Summary:
A Swift protocol extension's implementation of a static property that was declared in a public protocol causes the compiler to crash when the protocol extension's implementation is also declared public. A sample playground and crash log are attached.

Steps to Reproduce:
1. In a playground or other Swift file, declare a *public* protocol with a static property.
2. Create a protocol extension for it.
3. Implement the static property in the protocol extension by having it get and set some computed value (e.g. setting/getting a property in NSUserDefaults.standardUserDefaults()). Do NOT declare it public.
4. Create a *public* struct or class that implements the protocol.
5. The compiler will flag the static property in the protocol extension, saying that it needs to be public.
6. Add a public modifier to the property's implementation in the protocol extension, and watch the compiler crash with a segmentation fault.

Expected Results:
I expected the static property in the protocol extension to compile properly when being declared public.

Actual Results:
When the static property in the protocol extension is made public, then the Swift compiler crashes.

Version:
Xcode 7.3.1 (7D1014) with the iPhone 5 simulator running iOS 9.3, all on OS X El Capitan 10.11.6

Notes:


Configuration:
MacBook Pro (Retina, 15-inch, Late 2013), 2.3 GHz Intel Core i7, 16 GB memory

Attachments:
'PublicStaticProtocolExtensions.playground.zip' and 'com.apple.dt.Xcode.Playground_2016-08-25-125719_Developer-Jasons-laptop.crash' were successfully uploaded.