Prefer "#if os(Linux)" to "#if !os(macOS)

[stephencelis]

Currently, projects that use --generate-linuxmain will generate a file that breaks iOS and other platforms.

There may be more things that need to be fixed here, but this is a start. I noticed that throughout this project things are cased on os(macOS) a lot. Perhaps an audit is a good idea?

[SDGGiesbrecht]

This has been annoying me too for some time, but I haven’t gotten around to submitting a fix myself.

In this specific case (the generated test manifests), I think #if !canImport(ObjectiveC) is what we really want, since it won’t break Windows, Android, etc. like #if os(Linux) would.

[stephencelis]

@SDGGiesbrecht Good idea, thanks!

[SDGGiesbrecht]

@aciidb0mb3r

[ankitspd]

Thanks! Can you also run .build/x86_64-apple-macosx10.10/debug/spm test --generate-linuxmain to update SwiftPM's generated files?

[stephencelis]

@aciidb0mb3r What are the steps to getting there? I've built spm per the docs and there's no .build folder. I then ran swift build and the .build/x86_64-apple-macosx10.10/debug directory exists, but no spm executable. When I run .build/x86_64-apple-macosx10.10/debug/swift-test --generate-linuxmain, I get:

error: toolchain is invalid: could not find the swiftc at expected path /Users/stephencelis/Developer/apple/swiftpm/.build/x86_64-apple-macosx10.10/debug/swiftc

[ankitspd]

How did you build swiftpm? Don't run swift build directly. If you have the latest Xcode, Utilities/bootstrap should be enough to build it.

[stephencelis]

I followed the directions pointed to here:

https://github.com/apple/swift-package-manager/blob/master/Documentation/Development.md

Basically, ran ../swift/utils/build-script -R --llbuild --swiftpm.

[ankitspd]

Ah. That puts the build directory next to your checkout of SwiftPM. However, I would recommend following the second method unless you really require a compiler built from scratch: https://github.com/apple/swift-package-manager/blob/master/Documentation/Development.md#using-trunk-snapshot

[stephencelis]

Done! Probably would have been faster to manually update :) Took awhile to attempt to build with swift as a whole.

[millenomi]

To avoid making things harder for non-Linux porters, I’ve been slowly transitioning Foundation to #if canImport(Darwin) rather than using os with Apple OS names.

[stephencelis]

Should I change to #if !canImport(Darwin) instead? The ObjectiveC check seemed appropriate since the runtime is what's used to find all the test cases.

[ankitspd]

Done! Probably would have been faster to manually update :) Took awhile to attempt to build with swift as a whole.

I should update the dev docs. Given the source compatibility, compiling from scratch is rarely required.

[ankitspd]

I agree, ObjectiveC check seems more appropriate but Darwin should also work. Let me see if I can quickly check with someone from the Swift team.

[ankitspd]

I haven't heard back yet. Lets get this in, I'll update the code if I hear back about a preferred way.

[ankitspd]

@swift-ci smoke test

[ankitspd]

Failure seems related, I'll update the patch.

[ankitspd]

@swift-ci smoke test