Pass toolchainLibDir if using XCBuild

[neonichu]

We pass this as an additional -L when building with SwiftPM's own build system, so we should also pass this when using XCBuild.

rdar://82313817

[neonichu]

@swift-ci please smoke test

[neonichu]

Going the same route as how we are passing SWIFT_EXEC here, another option would be setting it in the PIF itself.

[abertelrud]

Looks good to me, and is similar to the SWIFT_EXEC that had to be added recently (the line above the one you added).

Are there other settings that we need to pass as well, of a similar ilk?

Also, are there any meaningful unit tests that can be added here? I added one for SWIFT_EXEC I think, maybe it can be extended.

[neonichu]

It looks like there are a few more settings which could be interesting:

• macosSwiftStdlib which gets passed passed to executables and tests on Darwin in the SwiftPM build system, so we should pass that via the PIF
• getClangCompiler() which we should probably also pass here
• extraCCFlags, extraSwiftCFlags and extraCPPFlags which I am not sure about whether we should pass them as overrides here or via the PIF

[neonichu]

16:05:21 Test Case 'APIDiffTests.testCheckVendedModulesOnly' started at 2021-08-27 18:03:56.638
16:05:21
/home/buildnode/jenkins/workspace/swift-package-manager-self-hosted-Linux-smoke-test/branch-main/swiftpm/Tests/CommandsTests/APIDiffTests.swift:144: error: APIDiffTests.testCheckVendedModulesOnly : XCTAssertTrue failed -
16:05:21 Test Case 'APIDiffTests.testCheckVendedModulesOnly' failed (21.405 seconds)

This doesn't look related.

[DougGregor]

I rudely committed my changes to see if everything will build together

[DougGregor]

@swift-ci please test

[DougGregor]

@swift-ci please smoke test

[DougGregor]

Since this change unblocks work on back-deploying concurrency, I'm going to go ahead and merge.

[tomerd]

Since this change unblocks work on back-deploying concurrency, I'm going to go ahead and merge.

@DougGregor

=> lets circle back to @neonichu above: #3695 (comment)

=> should adding this path also apply outside the context of XCBuild? ie when you using swift build on a mac we would want the same behavior, no?

=> finally, buildParameters.toolchain.toolchainLibDir points to where SwiftPM places its dylibs used to provide the manifest and plugins "scripts" APIs. What would create these new swift/macosx subdirectories and place libraries there

cc @abertelrud

[neonichu]

SwiftPM's build system already passes all these, it's just missing from builds with XCBuild as the build system.

I believe the libraries in swift/macosx get created by the compiler itself, e.g. this is where compatibility libraries end up (which initially spawned this PR).

[tomerd]

I believe the libraries in swift/macosx get created by the compiler itself, e.g. this is where compatibility libraries end up (which initially spawned this PR).

got it, is it new?

[DougGregor]

I believe the libraries in swift/macosx get created by the compiler itself, e.g. this is where compatibility libraries end up (which initially spawned this PR).

got it, is it new?

No, it is not new, but the set of compatibility libraries hasn't changed since Swift 5.1, which (I think) predates the introduction of this code path. The SwiftPM path gets it for free because the Swift driver is responsible for forming the link line, not XCBuild.