feat(wasi): normalize wasi error codes and exit-code propagation by eduardomourar · Pull Request #13625 · uutils/coreutils

eduardomourar · 2026-07-29T02:02:51Z

Continuation of #12653. Aligns error handling and exit codes on wasm32-wasip1/wasm32-wasip2 with native Unix behavior, and enables the wasip2 integration test suite.

Adds uucore::error::process_exit, used everywhere std::process::exit was called, so nonzero exit codes propagate correctly on wasip2 (behind an opt-in wasip2_exit_with_code feature; off by default since it requires a WASI host that supports the unstable exit-with-code function, e.g. wasmtime -S cli-exit-with-code=y).
Adds wasi_normalize_open_error/wasi_normalize_read_error/wasi_is_broken_pipe helpers to uucore::error and applies them across cat, rm, wc, csplit, tee, sort, seq, tr, tsort, split, and yes, so directory/broken-pipe errors surface the same ErrorKind and message as on Unix instead of WASI's raw, differently-numbered errnos.
Reworks uucore::fs::FileInformation to use real inode/device stat via rustix on WASI instead of a size/type heuristic.
Fixes WASI-specific gaps in cp (symlinks, attribute preservation), touch (timestamps), date (clock resolution, set-date), and sort (single-threaded ordering check, since WASI has no threads).
Adds/retargets integration tests across most utilities to cover the above, tags WASI-incompatible tests with #[cfg_attr(wasi_runner/wasip2_runner, ignore = "...")], and enables the wasip2 integration run in CI (previously wasip1-only).

github-actions · 2026-07-29T02:41:54Z

GNU testsuite comparison:

Skip an intermittent issue tests/tail/tail-n0f (fails in this run but passes in the 'main' branch)
Note: The gnu test tests/cut/cut-huge-range is now being skipped but was previously passing.
Note: The gnu test tests/seq/seq-epipe is now being skipped but was previously passing.
Congrats! The gnu test tests/unexpand/bounded-memory is now passing!

oech3 · 2026-07-29T05:33:49Z

Can we avoid introducing many code with match and cfg, and introduce a fn like process_wasi_err(e)?

codspeed-hq · 2026-07-29T22:26:23Z

Merging this PR will not alter performance

✅ 344 untouched benchmarks
⏩ 47 skipped benchmarks¹

_{Comparing eduardomourar:feat/wasi-error-handling (d311b90) with main (d99a177)}

47 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

eduardomourar · 2026-07-30T18:20:05Z

Can we avoid introducing many code with match and cfg, and introduce a fn like process_wasi_err(e)?

I had to create 3 separate functions to deal with normalizing the WASI errors, but I think it does what you asked.

On wasm32-wasip2, std::process::exit goes through WASI's stable wasi:cli/exit#exit, which only carries a success/failure bit and collapses every nonzero exit code to 1. This adds uucore::error::process_exit and an opt-in wasip2-exit-with-code feature that, when enabled, instead calls the unstable wasi:cli/exit#exit-with-code so real exit codes propagate; the feature requires a WASI host that explicitly supports it (e.g. wasmtime's -S cli-exit-with-code=y) and is off by default.

Route every direct std::process::exit call in the multi-call binary, uucore's #[uucore::main] macro, and per-util fatal-exit paths (cat, more, shred, sort, tail, tr, tty) through the new process_exit wrapper so they pick up correct wasip2 exit-code propagation when the wasip2-exit-with-code feature is enabled, with no behavior change on other targets.

WASI reports several conditions with different (or no) ErrorKind than native Unix: opening/removing a directory surfaces raw EBADF instead of EISDIR, reading from a directory-backed descriptor surfaces EISDIR under a different errno per preview version, and preview2 reports a broken pipe as raw EIO. This adds wasi_normalize_open_error, wasi_normalize_read_error, and wasi_is_broken_pipe to uucore::error so call sites can convert these to the same ErrorKind/behavior used on Unix; all three are no-ops off WASI. Also fixes read_os_string_lines to return an io::Error on invalid UTF-8 instead of panicking, since argv/filenames aren't guaranteed valid UTF-8 on WASI.

Route open/read errors through the new uucore::error normalization helpers so cat, rm, wc, csplit, tee, sort, seq, tr, tsort, and split report the same ErrorKind/message on WASI as on native Unix: opening or reading a directory now surfaces IsADirectory instead of a raw EBADF/EISDIR errno, and seq's broken-pipe short-circuit also catches preview2's raw EIO. rm and tsort gain small WASI-specific fallbacks (readability probing via read_dir, directory detection via stat) where the platform lacks the Unix APIs those checks normally use.

FileInformation previously fell back to a std::fs::Metadata-based heuristic (comparing file type and size) on WASI, since it lacked access to nix::sys::stat. Switch it to rustix::fs::Stat, the same backing type used on Unix, giving WASI real inode/device identity, nlink, and equality checks instead of an approximation. Also add WASI implementations of are_hardlinks_to_same_file and are_hardlinks_or_one_way_symlink_to_same_file via rustix::fs::stat/ lstat, since std::os::unix::fs::MetadataExt is unavailable there.

Several per-util operations relied on APIs unavailable or nightly-only on WASI: cp now treats ENOSYS like EOPNOTSUPP when skipping optional attribute preservation (WASI has no chmod/chown at all), reads timestamps via Metadata::accessed/modified instead of the filetime crate (which panics there), creates symlinks via rustix::fs::symlink, and only errors out of --reflink when explicitly requested rather than whenever it isn't Never. touch applies the same filetime-avoidance and uses rustix::fs::utimensat for symlink timestamps. date implements get_clock_resolution and set_system_datetime for WASI (the latter reporting "not supported", since the sandbox has no wall-clock-set syscall). sort's ordering check runs single-threaded on WASI, which has no thread support, and its external-merge path inserts a missing separator between concatenated files so lines don't merge across file boundaries.

Adds and retargets integration tests across most utilities to verify the WASI-specific behavior introduced in prior commits (error codes, symlink/hardlink handling, cp attribute preservation, sort ordering, touch timestamps, etc.), and tags tests that can't run under the WASI sandbox with #[cfg_attr(wasi_runner/wasip2_runner, ignore = "..")] (host paths, real threads, chmod/chown, and similar gaps). The uutests harness's symlink helpers now build relative targets under the WASI runner instead of absolute host paths, and gain a UUTESTS_WASM_RUNNER_ARGS env var. wasi.yml now runs the wasip2 integration suite (previously wasip1-only) with the wasip2_exit_with_code feature and wasmtime's cli-exit-with-code flag, and expands the tested utility list as WASI coverage grows. docs/src/wasi-test-gaps.md is expanded to catalog every ignore reason.

eduardomourar · 2026-08-01T09:00:37Z

I have put this one back to draft. It had too many files that were changed so I created the following spinoff PRs that need to be merged first:

eduardomourar force-pushed the feat/wasi-error-handling branch from ecc7c96 to 650e875 Compare July 30, 2026 18:09

eduardomourar changed the title ~~feat(wasi): convert wasi to posix error codes~~ feat(wasi): normalize wasi error codes and exit-code propagation Jul 30, 2026

eduardomourar force-pushed the feat/wasi-error-handling branch 2 times, most recently from f0f8959 to 60f692a Compare July 31, 2026 00:22

eduardomourar added 6 commits July 31, 2026 23:36

eduardomourar force-pushed the feat/wasi-error-handling branch from 60f692a to 9752428 Compare August 1, 2026 00:41

eduardomourar force-pushed the feat/wasi-error-handling branch from 9752428 to d311b90 Compare August 1, 2026 01:22

eduardomourar marked this pull request as draft August 1, 2026 08:59

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feat(wasi): normalize wasi error codes and exit-code propagation - #13625

feat(wasi): normalize wasi error codes and exit-code propagation#13625
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