[Qol]Fixit nested static value

[gibachan]

This PR fixes a insufficient fixit on use of static value in nested structure.

Resolves SR-5715.

[CodaFi]

I'm a little hesitant to print this directly, but it seems to be correct. Could you add a test that uses a generic nested type as well?

[slavapestov]

The declared interface type should be fine. It will use sugared generic parameter names and include the full parent type. So for a nested generic type, it should print Outer<T>.Inner<U, V>, etc, and we should add a test for this case.

[slavapestov]

Actually to handle members of protocols you want getSelfInterfaceType() instead. This is identical to getDeclaredInterfaceType() for concrete types, but for protocols it has 'Self' instead of the existential.

Right now, this produces a bad fixit:

protocol P {}

extension P {
  static func f() {}

  func g() {
    f
  }
}

ext.swift:7:5: error: static member 'f' cannot be used on instance of type 'Self'
    f
    ^
    P.

Note that the correct fix is to add 'Self.', not 'P.'.

@gibachan Do you mind adding a test for this case as well?

[gibachan]

Thank you for kind response.
I made those fixes, but now I get a strange error on the test you advised above.
When I run the test by utils/run-test, the error message says "use of unresolved identifier 'f'" instead of "static member 'f' cannot be used ...". However if I run it by ../build/Ninja-ReleaseAssert/swift-macosx-x86_64/bin/swift, it says "static member 'f' cannot be used ..." as I expect. I do not know the difference between them. Am I missing something?

[xwu]

Drive-by nit: could you please reformat these lines to use two-space indents like the rest of the file, and restore the trailing newline?

[gibachan]

Thanks, I did reformat lines.

[slavapestov]

Hi @gibachan, can you take a look at this PR? #11609 It looks like there are two very similar code paths in diagnostics to handle the same error of an instance member being used on static type value, or vice versa. Maybe there's a function that can be factored out here.

cc @Kacper20

[slavapestov]

Looks good, thanks! I'll look at the other code path later, maybe they're not really possible to unify.

[slavapestov]

@swift-ci Please smoke test

[slavapestov]

@swift-ci Please smoke test

[slavapestov]

Hi @gibachan, can you take a look at the test failure?

/Users/buildnode/jenkins/workspace/swift-PR-osx-smoke-test/branch-master/swift/test/expr/postfix/dot/dot_keywords.swift:104:31: error: incorrect message found
    f()   // expected-error {{static member 'f' cannot be used on instance of type 'Self'}} {{12-12=Self.}}
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                              use of unresolved identifier 'f'

[gibachan]

Hi @slavapestov, thank you for your support!
The failed test expects that statement lacks of 'Self.' but it was different because of swift version.
The expected error happens only with Swift4. With Swift3, it would be as described above.
Would you please let me know how to handle the different results by Swift version in test case like this situation? or any better approach?

[slavapestov]

Oh right, Swift 3 had a strange quirk with unqualified lookup vs static members...

You could update the test's RUN line to pass -swift-version 4, and add a new test case to test/Compatibility/ to test the old behavior.

Also do you know how to run the tests locally? That would save you a lot of time while iterating on this.

[gibachan]

Thanks @slavapestov! I followed your advice and I tried tests locally with utils/build-script -RT then it passed without any unexpected failures.
Could you please take a look at it?

[slavapestov]

@swift-ci Please smoke test