[anastygnome]

The implementation of test parsing was not all encompassing and missed a lot of cases from GNU. Notably test would process short expressions in a special way, which was absent in uutils. One test went against coreutils, probably because by default test uses a shell builtin.

This PR fixes all of the issues, at the expense of a comprehensive rewrite of the parser (sorry!). But it is at least a sane base to work upon.

closes #13197
closes #9147
closes #8960

[github-actions]

Binary size comparison:

Individual binary size comparison VS main (threshold: >=5% AND >=4 KB).

Total size of compared binaries: 155.68 MB (+2.41 MB, +1.58%)

Significant per-binary changes:
  [        1.12 MB ->    2.32 MB  (+1.20 MB, +107.32%)
  test     1.12 MB ->    2.32 MB  (+1.20 MB, +107.32%)

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/date/resolution (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/test/test is no longer failing!

[anastygnome]

@sylvestre looking good to me!

[anastygnome]

@cakebaker can you review?

[anastygnome]

@xtqqczze what do you think of this?

[anastygnome]

@cakebaker @xtqqczze I've rebased this. should be good to merge now :)

[xtqqczze]

needs review from @sylvestre

[cakebaker]

Congrats! The gnu test tests/test/test is no longer failing!

Kudos, good work, thanks!

[xtqqczze]

This broke the Redox targets:

$ RUSTC_BOOTSTRAP=1 cargo check -q -Zbuild-std --all-targets --features feat_os_unix_redox --target i586-unknown-redox --target x86_64-unknown-redox
error[E0432]: unresolved imports `rustix::fs::AtFlags`, `rustix::fs::accessat`
  --> src/uu/test/src/faccessat.rs:20:22
   |
20 |     use rustix::fs::{AtFlags, CWD, accessat};
   |                      ^^^^^^^       ^^^^^^^^ no `accessat` in `fs`
   |                      |
   |                      no `AtFlags` in `fs`
   |
help: a similar name exists in the module
   |
20 -     use rustix::fs::{AtFlags, CWD, accessat};
20 +     use rustix::fs::{OFlags, CWD, accessat};
   |
help: a similar name exists in the module
   |
20 -     use rustix::fs::{AtFlags, CWD, accessat};
20 +     use rustix::fs::{AtFlags, CWD, access};
   |

Unfortunately, the PR to add fs support for Redox in Rustix (bytecodealliance/rustix#1638) has been awaiting review for quite some time. Given the lack of progress, we may need to consider maintaining a fork of Rustix to unblock Redox support.

[anastygnome]

@xtqqczze I wrote a separate uucore PR recently #15294 that would fix this (or at least help)