I am a bit curious about Pushkar’s test case; perhaps it should be added as a test?
The SIL emitted then vs ~today looked very similar, so I was thinking the issue might be in IRGen. Scanning there, looks like this cured the problem: @shajrawi https://github.com/apple/swift/pull/9452 Disable large types irgen pass The property change happens when the pass is disabled, but before f9861fe6fcd9d797653f62a0b0c4142e719eecf1, the change does not happen: before => ready(test.TState(drain: test.Drain.foo("wow"))) after => ready(test.TState(drain: test.Drain.foo("wow"))) The `newValue` access in willSet apparently ‘alters’ it to the old value. https://bugs.swift.org/browse/SR-4852 Regards, Will Stanton > On May 10, 2017, at 1:08 PM, John McCall via swift-dev <swift-dev@swift.org> > wrote: > >> On May 10, 2017, at 11:06 AM, Pushkar N Kulkarni <pushkar...@in.ibm.com> >> wrote: >> The issue is seen with the 05-09 dev snapshot. However after updating the >> repos today, I no longer see it! >> >> Looks like one of yesterday's commits (which did not go into 05-09) fixed >> it. I am closing the JIRA report. Thanks! > > Okay, glad we managed to fix it; thanks. > > John. > >> >> Pushkar N Kulkarni, >> IBM Runtimes >> >> Simplicity is prerequisite for reliability - Edsger W. Dijkstra >> >> >> >> -----swift-dev-boun...@swift.org wrote: ----- >> To: John McCall <rjmcc...@apple.com> >> From: Pushkar N Kulkarni via swift-dev >> Sent by: swift-dev-boun...@swift.org >> Date: 05/10/2017 06:00PM >> Cc: swift-dev <swift-dev@swift.org> >> Subject: Re: [swift-dev] Property modification not taking effect >> >> Thanks John. This is the JIRA bug report: >> https://bugs.swift.org/browse/SR-4852 >> >> I was able to write a small test case that shows the regression: >> >> enum State { >> case ready(TState) >> case inProgress(TState) >> >> var isPaused: Bool { >> switch self { >> case .ready: return false >> case .inProgress: return false >> } >> } >> } >> >> enum Drain { >> case foo(String) >> case bar(Int, String) >> } >> >> struct TState { >> let drain: Drain >> } >> >> class Task { >> var state = State.ready(TState(drain: .foo("wow"))) { >> willSet { >> if newValue.isPaused { } >> } >> } >> >> func resume() { >> if case .ready(let tState) = state { >> print("before => \(state)") >> state = .inProgress(tState) //doesn't take effect >> print("after => \(state)") >> } >> } >> } >> >> //main >> Task().resume() >> >> Output with the latest master: >> before => ready(Test.TState(drain: Test.Drain.foo("wow"))) >> after => ready(Test.TState(drain: Test.Drain.foo("wow"))) >> >> >> Expected output (and with the 04-24 snapshot as well): >> before => ready(Test.TState(drain: Test.Drain.foo("wow"))) >> after => inProgress(Test.TState(drain: Test.Drain.foo("wow"))) >> >> >> Pushkar N Kulkarni, >> IBM Runtimes >> >> Simplicity is prerequisite for reliability - Edsger W. Dijkstra >> >> >> >> -----rjmcc...@apple.com wrote: ----- >> To: Pushkar N Kulkarni <pushkar...@in.ibm.com> >> From: John McCall >> Sent by: rjmcc...@apple.com >> Date: 05/10/2017 04:19AM >> Cc: swift-dev <swift-dev@swift.org> >> Subject: Re: [swift-dev] Property modification not taking effect >> >>> On May 9, 2017, at 3:07 PM, Pushkar N Kulkarni via swift-dev >>> <swift-dev@swift.org> wrote: >>> In the process of debugging a bunch of consistent failures in >>> TestFoundation/TestNSURLSession, I came across a weird problem symptom in >>> this line of code. >>> >>> internalState = .transferInProgress(transferState) >>> >>> I had a suspicion that the above modification is not taking effect, since, >>> only based on this change the didSet observer for the `internalState` >>> property triggers data transfers using libcurl. So, I simply printed the >>> property before and after the assignment. >>> >>> print("before => \(internalState)") >>> internalState = .transferInProgress(transferState) >>> print("after => \(internalState)") >>> >>> Surprisingly, I don't see any change in the property value: >>> before => transferReady(Foundation.URLSessionTask._TransferState(... >>> <redacted> ...)) >>> after => transferReady(Foundation.URLSessionTask._TransferState(... >>> <redacted> ...)) >>> >>> When I switched back to the "swift-DEVELOPMENT-SNAPSHOT-2017-04-24-a" tag >>> on all the repos (except swift-corelibs-foundation), I do not see this >>> problem. I see: >>> before => transferReady(Foundation.URLSessionTask._TransferState(... >>> <redacted> ...)) >>> after => transferInProgress(Foundation.URLSessionTask._TransferState(... >>> <redacted> ...)) >>> >>> To put it in simple terms, the modification doesn't seem to be taking >>> effect with the current HEAD. >>> >>> I haven't been able to isolate this problem in an independent test case. >>> However, anybody who wants to reproduce it can simply run TestFoundation >>> after enabling the URLSession tests (which have been disabled for now) in >>> TestFoundation/main.swift. >>> >>> I did compare the `-emit-ir` outputs from the passing and failing levels. >>> There seems to be a clear difference in the way we store the new value of >>> this property. But given my limited exposure to debugging Swift compiler >>> issues, I wasn't able to progress further. >>> >>> Can someone help us here please? Thanks. >> >> That sounds like a serious bug; please file it in JIRA. >> >> John. _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
