This commit does a bit of everything: refactors bits here and there,
fixes a bug discovered in another #701, and combines all structs that
we used in `yanix` and `wasi-common` crates to represent file types
on *nix into one struct, `yanix::file::FileType`.
Up until now, in `yanix`, we've had two separate structs used to
represent file types on the host: `yanix::dir::FileType` and
`yanix::file::SFlags` (well, not quite, but that was its main use).
They both were used in different context (the former when parsing
`dirent` struct, and the latter when parsing `stat` struct), they
were C-compatible (as far as their representation goes), and as it
turns out, they shared possible enumeration values. This commit
combines them both into an idiomatic Rust enum with the caveat that
it is now *not* C-compatible, however, I couldn't find a single use
where that would actually matter, and even if it does in the future,
we can simply add appropriate impl methods.
The combine `yanix::file::FileType` struct can be constructed in two
ways: 1) either from `stat.st_mode` value (and while we're here,
now it's done correctly according to POSIX which fixes the bug mentioned
in VFS impl PR #701), or 2) from `dirent.d_type` value. Also, since we now
have one struct for representing both contexts, this cleans up nicely
a lot of duplicated code in `host` module.
* Clean up fd_filestat_get implementation
This commit does 4 things:
* Adds `yanix::file::fstat`, a wrapper around `libc::fstat`.
* It essentially reverts 89fbde2 for Unix hosts -- in other words,
it brings back the use of `fstat` to obtain `libc::stat` from a
file descriptor, rather than relying on `std::fs::Metadata`. This
way, we reuse `host_impl::filestat_from_nix` in
`hostcalls_impl::fd_filestat_get` implementation rather than
unnecessarily duplicate code for converting filestats into
`__wasi_filestat_t`.
* Moves `crate::helpers::systemtime_to_timestamp` to Windows `host_impl`
module. It does the same thing with helpers which assist in converting
`std::fs::Metadata` into `__wasi_filestat_t`. This should retain symmetry
between *nix and Windows impls.
* Makes timestamp conversions in `host_impl::filestat_from_nix` fallible.
* Backport changes to snapshot0
* Signal no overflow with `from` rather than `as` cast
* Add yanix crate
This commit adds `yanix` crate as a Unix dependency for `wasi-common`.
`yanix` stands for Yet Another Nix crate and is exactly what the name
suggests: a crate in the spirit of the `nix` crate, but which takes a different
approach, using lower-level interfaces with less abstraction, so that it fits
better with its main use case, implementation of WASI syscalls.
* Replace nix with yanix crate
Having introduced `yanix` crate as an in-house replacement for the
`nix` crate, this commit makes the necessary changes to `wasi-common`
to depend _only_ on `yanix` crate.
* Address review comments
* make `fd_dup` unsafe
* rename `get_fd` to `get_fd_flags`, etc.
* reuse `io::Error::last_os_error()` to get the last errno value
* Address more comments
* make all `fcntl` fns unsafe
* adjust `wasi-common` impl appropriately
* Make all fns operating on RawFd unsafe
* Fix linux build
* Address more comments
