Repair the Windows SwiftPM build #5068
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Tests/Foundation/TestBundle.swift
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| // While this works on Linux due to special linker functionality, this doesn't work on Windows and results in a collision between the two main symbols | ||
| // SwiftPM also cannot support depending on this executable (to ensure it is built) without also linking its objects into the test runner | ||
| // For those reasons, using the xdgTestHelper on Windows is currently unsupported and tests that rely on it must be skipped | ||
| throw XCTSkip("xdgTestHelper is not supported during testing on Windows") |
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Hmm, this was usable when we were running the tests through CMake. I think that the issue is limited to SPM which doesn't build the libraries and tries to link the executable object library into another executable. Can we clarify this to be unsupported when running with SPM?
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Yes this is a limitation of SwiftPM that I've brought up to some of the SwiftPM folks - I see we have a few GitHub issues tracking it. SwiftPM attempts to link the object files from the executable into the test runner, and while this happens to work on Linux on Windows the two main functions have conflicting symbols and linking fails.
Can we clarify this to be unsupported when running with SPM?
Is there something that you'd like me to add in addition to the comment that I added here? I think that comment should explain why SwiftPM cannot support this but I'm happy to add any details that you think are missing.
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Can we update the message of the XCTSkip to call out that this is unsupported with SPM?
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Sure, added in 595a4e9
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@swift-ci please test |
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@swift-ci please test Linux platform |
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@swift-ci please test |
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@swift-ci please test Windows platform |
swiftlang/swift-package-manager#6367 is tracking this issue, and I think it's effectively the same as swiftlang/swift-package-manager#7174 as well (also rdar://133768835) |
We currently run unit tests via SwiftPM on linux, but have not yet enabled this on Windows due to the Windows build failing. This is a large step forward towards getting the Windows build working via SwiftPM as it resolves a few main issues:
pkgconfigon Linux, however the same functionality does not exist on Windows operating systems. Additionally, we cannot find these libraries in the toolchain like Dispatch because, unlike libdispatch, curl/libxml2 are not distributed in the toolchain (they only exist as static libraries linked into FoundationNetworking/FoundationXML respectively. Instead, on windows we require that the header include and library search paths are provided via environment variables. While this doesn't make this easy for local development, it does allow us to run these tests in Windows toolchain CI where we have already built copies of libxml2/curl for use in the toolchain, and we can provide paths into the build directory for this projects__CFInitializeproperly runs. In the SwiftPM build, Foundation is statically linked into the test executable. This means that theDllMainthat the toolchain build relies upon will not be invoked. Instead, we use an__attribute__((constructor))to initialize CF when the executable is launchedxdgTestHelperexecutable. There is no way within SwiftPM to specify a dependency on thexdgTestHelperwithout linking itsmain.swift.oobject file into the test executable. This happens to work on Linux due to a linker feature we've implemented on that platform, but causes symbol collisions on Windows due to the lack of this linker feature. Since there is no official support for this feature in SwiftPM packages, we must instead disable these tests.The tests don't run successfully yet (we crash in the
DateFormattertests due to aCFTimeZoneissue that I'm investigating), but with this I can at least successfully launch the tests which is a great start.