0.4.0

Release 0.4.0

Technical write-up: https://katei.dev/blog/2026/09/18/wasmkit-0-4-0/

What's Changed

• Add wasmkit.svg by @MaxDesiatov in #366
• WasmParser: Remove consume(_ expected: Set<UInt8>) from ByteStream by @kateinoigakukun in #367
• WasmParser: Stop taking FilePath in detectWasmFileType by @kateinoigakukun in #368
• CI: Skip redundant benchmark runs to reduce CI time by @kateinoigakukun in #370
• WasmParser: Add FileSystem trait to allow omitting file system helpers by @kateinoigakukun in #369
• NFC: Remove unnecessary returns by @kkebo in #372
• Update Swift SDKs for Swift 6.3.3 by @MaxDesiatov in #374
• Bump Amazon Linux version to 2023 in README.md by @MaxDesiatov in #375
• Upgrade swift-system dependency version by @MaxDesiatov in #376
• Bump version to 0.3.1 by @MaxDesiatov in #377
• Revert "Benchmark with native build system in dev snapshot builds" by @MaxDesiatov in #378
• Add Relaxed SIMD proposal implementation by @MaxDesiatov in #373
• Support extended-const arithmetic in constant expressions by @MaxDesiatov in #371
• Add wat2wasm example compatible with Embedded Swift by @MaxDesiatov in #273
• Move byte-stream offset control out of the I/O sources by @kateinoigakukun in #379
• Add shared memory support for mprotect-able platforms by @kateinoigakukun in #380
• Defensive WIT overlay symbols qualification by @MaxDesiatov in #384
• SwiftSyntax-based WITExtractor re-implementation by @MaxDesiatov in #381
• Debugger: fix step-into for calls w/ arguments, add qWasmGlobal by @MaxDesiatov in #385
• Move StatsCollector behind an EngineStats package trait by @kateinoigakukun in #388
• Make _CWasmKit headers portable to non-Clang compilers by @kateinoigakukun in #389
• Add MultiThread trait and PlatformMutex wrapper by @kateinoigakukun in #390
• Add printable core types and a typed Trap kind in WasmKitError by @kateinoigakukun in #391
• Remove ImportError and restrict ResourceLimiter to class types by @kateinoigakukun in #393
• Replace EntityHandle dynamicMemberLookup with explicit accessors by @kateinoigakukun in #394
• Support Embedded Swift in the core engine by @kateinoigakukun in #395
• Add ESP32 example with a portable smoke test by @kateinoigakukun in #396
• Drop swift-system dependency from WasmParser and WasmKit by @kateinoigakukun in #397
• Add --argv0 and --dir host::guest mapping to wasmkit run by @MaxDesiatov in #392
• Replace SystemExtras with an internal, injectable platform layer in WASI by @kateinoigakukun in #398
• Make the debugger stack sans-IO and drop NIO, swift-log, and swift-system by @kateinoigakukun in #399
• Fix the 32-bit wasm memory page limit on 32-bit hosts by @kateinoigakukun in #401
• Drop the async withThrowing/CleanupFailure overloads from WASI by @kateinoigakukun in #402
• Use a PlatformMutex in WASI instead of Synchronization.Mutex by @kateinoigakukun in #403
• Decouple WASIFile from GuestMemory by @kateinoigakukun in #404
• Make the WASI host module table generic over guest memory by @kateinoigakukun in #406
• Allow linking a subset of the WASI preview1 surface by @kateinoigakukun in #407
• Decouple WASIDir from its associated iterator type by @kateinoigakukun in #408
• Cover WASI in the embedded check and strip unused code by @kateinoigakukun in #409
• Run a WASI guest on emulated hardware in the ESP32 example by @kateinoigakukun in #410
• Run the GDB stub on embedded targets by @kateinoigakukun in #411
• Materialize stack-live constants on block entry by @kateinoigakukun in #412
• Do not read a host callee as a wasm function when stepping by @kateinoigakukun in #405
• Accept an empty value for an --env variable by @JDevlieghere in #414
• Add wasmkit-cli wast subcommand w/ new WASTRunner module by @MaxDesiatov in #415
• Demote debugger server lifecycle logs to trace by @JDevlieghere in #416
• Stop leaking and losing breakpoints while stepping by @JDevlieghere in #417
• Exit with the client and detach from the guest by @JDevlieghere in #418
• Add support for LLDB's updated qWasmGlobal packet by @JDevlieghere in #420
• Advertise the qWasmInstance+ feature LLDB looks for by @JDevlieghere in #422
• Report the guest's exit status instead of dropping the connection by @JDevlieghere in #424
• Report a stop at the start of the instruction run by @JDevlieghere in #425
• Bind breakpoint resolution to the containing function by @JDevlieghere in #426
• Support writing guest linear memory by @JDevlieghere in #427
• Add WASI Threads thread-spawn support by @kateinoigakukun in #423
• Add a wasmi-benchmarks replay harness under Benchmarks/ by @kateinoigakukun in #429
• Recommend --omit-frame-pointers for Linux release builds and use it for release artifacts by @kateinoigakukun in #430
• Use memmove for bulk memory and table copies by @kateinoigakukun in #432
• Answer qMemoryRegionInfo with the region containing an address by @JDevlieghere in #428
• Fuse integer comparisons into conditional branches by @kateinoigakukun in #433
• Split global.get/global.set by value shape and drop the storage tag by @kateinoigakukun in #434
• Collapse br_if landing pads that copy nothing into a single branch by @kateinoigakukun in #435
• Make wasm-to-wasm return call-free and merge frame initialization into one copy by @kateinoigakukun in #436
• Make memory load/store handlers frame-free with a single bounds-check branch by @kateinoigakukun in #437
• Relink local.tee and v128 producers into the local's slot by @kateinoigakukun in #439
• Store VReg as a pre-shifted byte offset by @kateinoigakukun in #444
• Fuse float compares into branches and add two-op float superinstructions by @kateinoigakukun in #445
• Read one-slot immediates as a single word and hoist the next-handler load by @kateinoigakukun in #446
• Fuse and-tests into conditional branches by @kateinoigakukun in #447
• Add two-operation integer superinstructions by @kateinoigakukun in #448
• Copy the direct-threaded handler table once instead of per emitted instruction by @kateinoigakukun in #449
• Hand integer values to the next instruction in an accumulator register by @kateinoigakukun in #451
• Route load and store operands through the accumulator on 32-bit memories by @kateinoigakukun in #452
• Hand f64 values to the next instruction in a float accumulator register by @kateinoigakukun in #453
• Carry integer constant operands in the instruction by @kateinoigakukun in #454
• Hand values that are read again later to the next instruction in the accumulator by @kateinoigakukun in #456
• Keep a value in the accumulator across one copy into a local by @kateinoigakukun in #457
• Inline br_table into its handler by @kateinoigakukun in #458
• Select values instead of registers and hand select its condition in the accumulator by @kateinoigakukun in #459
• Report a trap as a stop rather than losing the connection by @JDevlieghere in #468
• Package.swift: make warnings-as-errors opt-in via WASMKIT_WARNINGS_AS_ERRORS by @shopifyski in #469
• Run two adjacent register copies in one instruction by @kateinoigakukun in #460
• Weight every operand of the memory bounds check so the in-bounds path falls through by @kateinoigakukun in #461
• Fix recurring flaky CI failures: SwiftPM prebuilts race, libdispatch SIGSEGV, Android snapshot restore by @kateinoigakukun in #470
• Keep f32 values in FP registers by @kateinoigakukun in #462
• Make the parser's instruction dispatch inlinable so the translator gets a specialized copy by @kateinoigakukun in #463
• Fold an integer comparison into the select that consumes it by @kateinoigakukun in #464
• Fold a copy into the load that reads the copied address by @kateinoigakukun in #465
• Shrink the code generated per opcode outside the handlers by @kateinoigakukun in #466
• Batch fixes found by fuzzers by @kateinoigakukun in #472
• Fix Embedded Swift builds on ARM and on host platforms by @kateinoigakukun in #473
• Bump version to 0.4.0 by @kateinoigakukun in #471

New Contributors

• @JDevlieghere made their first contribution in #414
• @shopifyski made their first contribution in #469

Full Changelog: 0.3.0...0.4.0