undefined symbols (RegexParser)

[svanimpe]

Steps to reproduce:

• Create a new package with swift package init --type executable
• Add JavaScriptKit as a dependency. My Package.swift file is as follows:

  // swift-tools-version: 5.9
  // The swift-tools-version declares the minimum version of Swift required to build this package.
  
  import PackageDescription
  
  let package = Package(
    name: "RegexParserIssue",
    dependencies: [
        .package(url: "https://github.com/swiftwasm/JavaScriptKit", from: "0.19.0")
    ],
    targets: [
        .executableTarget(
            name: "RegexParserIssue",
            dependencies: [
                .product(name: "JavaScriptKit", package: "JavaScriptKit")
            ]
        ),
    ]
  )
  

• Build using:

  swift build --triple wasm32-unknown-wasi -Xswiftc -static-stdlib -Xswiftc -Xclang-linker -Xswiftc -mexec-model=reactor -Xlinker --export=__main_argc_argv
  

This results in a long list of errors like:

wasm-ld: error: /Users/steven/Library/Developer/Toolchains/swift-wasm-6.0-SNAPSHOT-2024-04-16-a.xctoolchain/usr/lib/swift_static/wasi/libswift_StringProcessing.a(_StringProcessing.o): undefined symbol: $s12_RegexParser3ASTV28GlobalMatchingOptionSequenceVMn
wasm-ld: error: /Users/steven/Library/Developer/Toolchains/swift-wasm-6.0-SNAPSHOT-2024-04-16-a.xctoolchain/usr/lib/swift_static/wasi/libswift_StringProcessing.a(_StringProcessing.o): undefined symbol: $s12_RegexParser13PrettyPrinterVMn
wasm-ld: error: /Users/steven/Library/Developer/Toolchains/swift-wasm-6.0-SNAPSHOT-2024-04-16-a.xctoolchain/usr/lib/swift_static/wasi/libswift_StringProcessing.a(_StringProcessing.o): undefined symbol: $s12_RegexParser9_TreeNodeMp
wasm-ld: error: /Users/steven/Library/Developer/Toolchains/swift-wasm-6.0-SNAPSHOT-2024-04-16-a.xctoolchain/usr/lib/swift_static/wasi/libswift_StringProcessing.a(_StringProcessing.o): undefined symbol: $s12_RegexParser9_TreeNodeP8childrenSayxGSgvgTq
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Workaround:

Add import _RegexParser in a Swift file.

Environment:

swift-wasm-6.0-SNAPSHOT-2024-04-16-a-macos_x86_64

[svanimpe]

I've also encountered this issue when using JSONEncoder from Foundation, in a project that doesn't use JavaScriptKit.

[kateinoigakukun]

https://github.com/kateinoigakukun/swiftwasm-issue-gh-5580

I finally could reproduce the issue and it's already incidentally fixed by --gc-sections support in the main branch. So it's reproducible with 6.0 snapshot.

But the root cause is still unclear... There should be something wrong in incremental compilation of swift-driver, so it might happen again