[ASDAlexander77]

The default library for wasm32-unknown-unknown and wasm64-unknown-unknown, under -mm=rc, none and own.

• scripts/build_wasm.bat (Windows) and scripts/build_wasm.sh (Linux) build lib/<wasm32|wasm64>/unknown/unknown/unknown/<release|debug>/<rc|none|own>/libTypeScriptDefaultLib.a, from lib.ts and the new OS layer src/lib.wasm.ts, archived with llvm-ar.
• No C++ wrappers: these targets have no C library. tslang links a wasm program with --allow-undefined, so the C functions and the wrappers' functions are imports from env. The host implements them; the compiler repo's docs/how/wasm/test/host.mjs is that host, for Node and browsers.
• lib.wasm.ts declares no C data, because an undefined data symbol is never resolved; the time zone comes from the host. Its signatures match the declarations in lib.ts exactly, because wasm-ld checks them (convertInteger takes a long, snprintf returns an int).
• No gc build: the collector is not built for wasm.

Goes with the compiler PR (wasm-defaultlib), which reads this archive's borrow facts under -mm=own.

Tests

The compiler repo's docs/how/wasm/test/run_tests.mjs --suite=defaultlib compiles tests/*.ts against the wasm archives and runs them under Node 26. On wasm32 and wasm64, in release and in debug, 181 pass under none and rc and 180 under own.

• Skipped:
  • tests that catch an exception: try/catch does not catch on wasm yet
  • async and threads
  • fetch.ts: the host has no network
  • tests marked // gc only and // linux only, and, under own, // not own
• Not run: build_wasm.sh on a Linux host. It was run from Git Bash against the Windows tslang.

🤖 Generated with Claude Code