0.3.0

WasmKit 0.3.0 is a substantial release with these notable changes:

• Initial WebAssembly Component Model support hidden behind a non-default package trait ComponentModel: binary parser/encoder, ComponentInstance/ComponentLoader, and invocation of simple components with WAVE value encoding arguments that can be passed from the CLI;
• Three new Wasm proposals (Fixed Width SIMD, Atomics, and Exception Handling);
• Substantially expanded WASIp1 coverage with poll_oneoff support for timers, an in-memory file system, thread safety improvements, and fd-leak I/O fixes;
• Under the hood WasmKit adopts typed throws via a unified WasmKitError and raises the minimum Swift version to 6.3.

What's Changed

• Add help strings to WITTool CLI options by @MaxDesiatov in #254
• NFC: make CLI commands reusable with new CLICommands module by @MaxDesiatov in #249
• Tests: Migrate rest of test suites to use swift-testing by @kateinoigakukun in #256
• WAT: Add threads proposal support by @kateinoigakukun in #257
• Add toolchain snapshots macOS matrix to main.yml by @MaxDesiatov in #253
• format.yml: use minimum supported Swift version by @MaxDesiatov in #258
• WASI MemoryFileSystem by @kateinoigakukun in #259
• Examples: Cover string passing use case in the example project by @kateinoigakukun in #260
• WASI: Implement path_readlink by @kateinoigakukun in #261
• WASI: Fix preopen ordering issue by @kateinoigakukun in #262
• CI: Skip const.wast spectest on main-nightly toolchains by @kateinoigakukun in #264
• WasmParser: SIMD Support by @kateinoigakukun in #263
• Fix CI: WITExtractor plugin smoke JSON decode diagnostics by @kateinoigakukun in #269
• Make MemoryEntity ~Copyable and store bytes in UnsafeBufferPointer by @kateinoigakukun in #268
• Adopt typed throws in the WAT module, require Swift 6.1 by @MaxDesiatov in #265
• Change swift-format category to formatting in dependencies.json by @MaxDesiatov in #267
• Fix all warnings by @kateinoigakukun in #271
• Remove generic Stream and StreamError types by @MaxDesiatov in #276
• Update MSSV in README.md to reflect recent bump to 6.1 by @MaxDesiatov in #279
• Add WasmParserBenchmark, CI job to verify that benchmarks build by @MaxDesiatov in #278
• Update Benchmarks/README.md for library benchmarks by @MaxDesiatov in #280
• Mark InstructionVisitor as ~Copyable by @MaxDesiatov in #281
• Implement SIMD support in runtime by @kateinoigakukun in #270
• Include threads proposal tests in runtime spectest by @kateinoigakukun in #284
• Bump build-xcode deps to macOS 26 and Xcode 26.2 by @MaxDesiatov in #285
• WASI: Inherit stdio by default in WASIBridgeToHost by @kateinoigakukun in #286
• Add Vendor/component-model test suite dependencies by @MaxDesiatov in #287
• Re-enable all tests for nightly Swift toolchains by @MaxDesiatov in #288
• WAT: basic Component Model definitions parsing by @MaxDesiatov in #266
• FuzzDifferential: cover v128/ref defaults for fuzz harness by @kateinoigakukun in #289
• Add component binary encoder, enable some CM spec tests by @MaxDesiatov in #290
• Add component binary parser and parsed representation by @MaxDesiatov in #291
• Add option to wat2wasm for including name section in output by @MaxDesiatov in #292
• Add WITTypeConverter to extract ComponentValueType from WIT by @MaxDesiatov in #294
• Add component aliases WAT parsing and encoding by @MaxDesiatov in #293
• Add ComponentInstance/ComponentLoader types by @MaxDesiatov in #296
• Add basic WAVE (WebAssembly Value Encoding) APIs by @MaxDesiatov in #297
• Support running components with WAVE in CLI by @MaxDesiatov in #298
• .github/workflows/cflite_pr.yml: use older runner version by @MaxDesiatov in #300
• Enable more CM tests, including assert_return/assert_trap by @MaxDesiatov in #299
• Add component WAT support to wat2wasm CLI by @MaxDesiatov in #301
• Fix WAVE argument parsing not using component's type resolver by @MaxDesiatov in #302
• Add ComponentBinaryFormat to centralize CM opcodes by @MaxDesiatov in #303
• NFC: Adopt ComponentBinaryFormat API in ComponentParser.swift by @MaxDesiatov in #304
• Disable PluginSmokeTests on macOS by @MaxDesiatov in #306
• Group Wasm proposals by phase in README.md by @MaxDesiatov in #309
• Fix fts_read() for cyclic symlinks by @MaxDesiatov in #307
• Specify WasmKit versions for Wasm proposals in README.md by @MaxDesiatov in #310
• Test with Xcode 26.3/Swift 6.2.4 by @MaxDesiatov in #312
• Bump Wasm Swift SDK to 6.2.4 in workflows/main.yml by @MaxDesiatov in #314
• Fix file descriptor leak by @kkebo in #315
• Bump actions/upload-artifact from 6 to 7 by @dependabot[bot] in #317
• Bump actions/download-artifact from 7 to 8 by @dependabot[bot] in #316
• Fix poll_oneoff and more I/O syscalls in WASI 0.1 by @MaxDesiatov in #187
• Fix wasm-tools path in WasmTools.swift by @MaxDesiatov in #320
• Clean up sections batching in ComponentEncoder by @MaxDesiatov in #323
• Fix lldb-dap connection, add decodingUnknownCommand test by @MaxDesiatov in #324
• Analyse control flow in runPreservingCurrentBreakpoint by @MaxDesiatov in #313
• CM WAT normalization: remove ComponentEncoder.GroupedFields by @MaxDesiatov in #325
• Debugger fixes: add test coverage for multiple functions by @MaxDesiatov in #326
• Fix core modules name section incompleteness by @MaxDesiatov in #321
• ComponentLinker: add ComponentTypeSerializer by @MaxDesiatov in #319
• Back atomic instructions by C11 stdatomic.h by @MaxDesiatov in #308
• Add Caller.captureBacktrace() by @pcbeard in #328
• Update actions/checkout to v6 by @MaxDesiatov in #330
• mprotect-based memory boundary checking by @kateinoigakukun in #272
• Bump actions/deploy-pages from 4 to 5 by @dependabot[bot] in #333
• Disable main branch of Android snapshots as regressed by @MaxDesiatov in #336
• Use unified WasmKitError for typed throws by @MaxDesiatov in #277
• Bump actions/upload-pages-artifact from 4 to 5 by @dependabot[bot] in #338
• CI: Temporarily disable main toolchain dev snapshots by @MaxDesiatov in #340
• Remove any GuestMemory existential from *Guest*Pointer types by @MaxDesiatov in #339
• Fix fd handling in WASIp1 implementation by @MaxDesiatov in #327
• Add Xcode 26.5 to the testing matrix by @MaxDesiatov in #345
• Revert "CI: Temporarily disable main toolchain dev snapshots" by @MaxDesiatov in #344
• Update actions/checkout to v6 in format.yml workflow by @MaxDesiatov in #348
• SystemExtras: stop shadowing the C stat type (fixes build with swift-system 1.7.0) by @jackguac in #349
• Add support for Exceptions Handling proposal by @MaxDesiatov in #311
• Bump clusterfuzzlite to Ubuntu 24.04 and Swift 6.3.2 by @MaxDesiatov in #350
• Bump MSSV to Swift 6.3 by @MaxDesiatov in #351
• Make InstructionTranslator non-copyable by @MaxDesiatov in #209
• Update benchmark package dependency URL by @MaxDesiatov in #354
• Add ThrowingDefer helper to unify defer error handling by @MaxDesiatov in #346
• Package.swift: add .treatAllWarnings(as: .error) by @MaxDesiatov in #282
• Make WASIBridgeToHost thread-safe by @MaxDesiatov in #347
• Represent CM valtypes as type index or inline primitive by @MaxDesiatov in #353
• Add Sendable conformance to CatchClause and TryCatch by @MaxDesiatov in #355
• Per-node locking for the in-memory WASI file system by @MaxDesiatov in #358
• Add merge_group to main.yml CI triggers by @MaxDesiatov in #356
• Benchmark with native build system in dev snapshot builds by @MaxDesiatov in #361
• Fuzzing: Guarantee that module instantiation will finish eventually by @kateinoigakukun in #364
• WASI: Fix fd leak in fd_readdir by @kateinoigakukun in #363
• Bump version to 0.3.0 by @MaxDesiatov in #360
• Update macOS runner version in release workflow by @MaxDesiatov in #365

New Contributors

• @jackguac made their first contribution in #349

Full Changelog: 0.2.2...0.3.0