Improve _format command

[keith]

This makes 2 changes to _format:

1. Only invoke swift-format once, this is helpful for larger projects
2. Include the Package.swift file for formatting

[neonichu]

@swift-ci please smoke test

[keith]

I don't believe the failure here is related

[tomerd]

@abertelrud this is something we should refactor out a plugin when the framework is ready. could you please review in that light.

[tomerd]

@swift-ci please smoke test

[neonichu]

Seems like this failure is new and reproduces, but unrelated to this PR:

10:56:17 Test Suite 'IntegrationTestsPackageTests.xctest' started at 2021-08-23 10:55:27.220
10:56:17 Test Suite 'XCBuildTests' started at 2021-08-23 10:55:27.220
10:56:17 Test Case '-[IntegrationTests.XCBuildTests testLibraryProductsAndTargets]' started.
10:56:17 
/Users/buildnode/jenkins/workspace/swift-package-manager-with-xcode-self-hosted-PR-osx/branch-main/swiftpm/IntegrationTests/Tests/IntegrationTests/XCBuildTests.swift:228: error: -[IntegrationTests.XCBuildTests testLibraryProductsAndTargets] : failed - Command failed with exit code: terminated(code: 1) - command: /Users/buildnode/jenkins/workspace/swift-package-manager-with-xcode-self-hosted-PR-osx/branch-main/swiftpm/.build/x86_64-apple-macosx/debug/swift-build --package-path /var/folders/_8/79jmzf2142z2xydc_01btlx00000gn/T/XCBuild_Libraries.WGF8ry/Foo --build-system xcode --target FooLib```

[neonichu]

I can repro the failure locally.

[neonichu]

Looks like some of the builds are simply failing, but we aren't propagating the errors from XCBuild correctly.

[neonichu]

The underlying error is: Found multiple targets named 'FooLib' which is true, there a package product target and a standard target with that name, but this doesn't seem like something we recently changed? Possibly Xcode on CI was an older version and this error exists for a while?

[neonichu]

Seems like this indeed works when using 12.5 as the installed Xcode, so this isn't due to any changes to SwiftPM.

[neonichu]

I think the most reasonable thing for now is to change the test so that it doesn't hit this and then figure out whether SwiftPM and/or XCBuild should change separately. We should also fix SwiftPM's parsing of XCBuild's output so that we don't drop the error on the floor.

[abertelrud]

@abertelrud this is something we should refactor out a plugin when the framework is ready. could you please review in that light.

Absolutely — I didn't actually realize there was a command for this already; the mentioning of swift-format as an example subcommand plugin was based on use cases, not an awareness of this code. This diff seems totally finally in relation to the existing code; when implemented as a plugin, it should have more robust emitting of output, and I'll also want to look closer at what it's using the PackageBuilder output for, since that isn't something plugins have access to now.

[abertelrud]

@abertelrud this is something we should refactor out a plugin when the framework is ready. could you please review in that light.

Absolutely — I didn't actually realize there was a command for this already; the mentioning of swift-format as an example subcommand plugin was based on use cases, not an awareness of this code. This diff seems totally finally in relation to the existing code; when implemented as a plugin, it should have more robust emitting of output, and I'll also want to look closer at what it's using the PackageBuilder output for, since that isn't something plugins have access to now.

Oh wait, PackageBuilder just construct the memory model of a package, it doesn't actually create a build system for building the package — name is confusing.

[neonichu]

@swift-ci please smoke test

[keith]

Thanks!

[tomerd]

thank you @keith