Build and test Swift natively on a Windows host#1819
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Builds on the linkshared and Swift SDK framework PRs. Adds native Windows host toolchain support to the standalone toolchain path (the <arch>-unknown-windows-msvc triple, MSVC link.exe semantics, auto-configuring a toolchain from an installed swiftc), plus independent test_observer / worker fixes (extended-length paths, space-in-path object names, corelibs-xctest runner) that were bundled into the original combined PR. CI gains a Windows task building //tools/... and the xplatform examples and running the xctest example.
- Probe Python interpreters more robustly: drop the in-function nil guard (the caller now checks `candidate and ...`), prefer python3-named binaries before unsuffixed ones, and confirm the interpreter is Python 3 (the caller needs the Python 3 plistlib API), addressing the "could `python` be Python 2?" concern. - Trim several over-long comments (object-file space sanitization, the Windows triple synthesis, the cc-toolchain clang requirement, and the Info.plist / ProgramData notes) per review.
Trim the target-triple and clang-carve-out comments per review. Claude-Session: https://claude.ai/code/session_01SmG1kqA3qB4WsLGU2xavuJ
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Windows host toolchain support + miscellaneous fixes, part of the #1809 split, on
top of the now-merged foundation PRs #1820 (
swift_binary(linkshared)) and #1821(Swift-SDK framework).
What this adds
Native Windows host toolchain support on the standalone toolchain path (the
<arch>-unknown-windows-msvctriple, MSVClink.exesemantics, auto-configuringa toolchain from an installed
swiftc), plus independenttest_observer/worker fixes (extended-length paths, space-in-path object names, corelibs-xctest
runner) that were bundled into the original combined PR. CI gains a Windows task
building
//tools/...+ the xplatform examples and running thexctestexample.Open questions
both
link.exeand a hermeticlld-linkaccept the/ALTERNATENAME//IGNORE:4217flags used here. I can key the flags off the linker rather thanthe OS if you want it to compose with
clang-clexplicitly. (@dzbarsky)swift_autoconfigurationparses the SDKInfo.plist(a plist,not JSON) in a repository rule. The clean fix is to parse
XCTEST_VERSIONinStarlark and drop Python; I'd do it in a follow-up CI can validate, since I
can't exercise the Windows path locally. (@dzbarsky)