Add Wasm builds to pull_request.yml

[MaxDesiatov]

This ensures that builds of swift-format for WASI don't regress.

[MaxDesiatov]

cc @kkebo

[kkebo]

To build swift-format for WASI, we need some fixes.

The main blockers are:

• DirectoryEnumerator

  • swift-format/Sources/SwiftFormat/Utilities/FileIterator.swift

    Line 88 in 1058a40

    dirIterator = FileManager.default.enumerator(

  • https://github.com/swiftlang/swift-corelibs-foundation/blob/cfc5a167e36447db3008e1f2b3c4d99475380a89/Sources/Foundation/FileManager%2BPOSIX.swift#L314-L333
  • Since FTS is already available, this might be solvable now.
    • Initial FTS support WebAssembly/wasi-libc#522
    • [wasm] Update wasi-libc to 25 swift#81252
• swift-markdown
  • feat: add partial support for WASI swift-cmark#75 has been merged, but not yet released.
• Atomic file writing

  • swift-format/Sources/swift-format/Frontend/FormatFrontend.swift

    Line 66 in 1058a40

    try bufferData.write(to: url, options: .atomic)

  • Atomic file writing for WASI swift-foundation#1557
• Functions declared without prototypes

  • swift-format/Sources/_SwiftFormatInstructionCounter/include/InstructionsExecuted.h

    Line 17 in 1058a40

    uint64_t getInstructionsExecuted();

  • Fatal error during compilation (Functions with 'no-prototype' attribute must take varargs) swiftwasm/swift#5572
• swift-corelibs-libdispatch

main...kkebo:swift-format:wasm32-wasi#files_bucket

[allevato]

swift-corelibs-libdispatch

Certainly happy to dust off #675 again if it makes this requirement go away.

[MaxDesiatov]

Yes, removing the Dispatch dependency would be greatly appreciated! 🙏

[MaxDesiatov]

• Atomic file writing

Is this required for in-place formatting? I wonder if a better near-term option is just to disable directly in-place formatting in files, and IIUC in-place formatting in memory would still be possible when SwiftFormat is used as a library?

[kkebo]

@MaxDesiatov

Is this required for in-place formatting?

Yes, it is.

I wonder if a better near-term option is just to disable directly in-place formatting in files

That's one option. Or, how about using non-atomic file writing for WASI?

and IIUC in-place formatting in memory would still be possible when SwiftFormat is used as a library?

What does "in-place formatting in memory" mean? IIUC swift-format with in-place disabled will only print the formatting results.

[MaxDesiatov]

That's one option. Or, how about using non-atomic file writing for WASI?

IMO that's a significant change in behavior with potential for unexpected data loss. I'd prefer that to be a new CLI flag, like --in-place-nonatomic.

What does "in-place formatting in memory" mean? IIUC swift-format with in-place disabled will only print the formatting results.

I'm referring to the SwiftFormat library product, not the executable. I'm not familiar with its API, but isn't there something there would allow in-place in-memory formatting that someone could rely on, say in a browser editor or something like that?

[allevato]

I'm referring to the SwiftFormat library product, not the executable. I'm not familiar with its API, but isn't there something there would allow in-place in-memory formatting that someone could rely on, say in a browser editor or something like that?

SwiftFormat the library API doesn't write files at all, directly. The various APIs can take either a URL to read from or a String with the source as inputs, and they write the output by calling TextOutputStream.write, so the behavior is based on whatever the caller's abstraction does.

Only the swift-format executable product needs atomic file writes.