* Introduce WasiCtxBuilderError error type
`WasiCtxBuilderError` is the `wasi-common` client-facing error type
which is exclusively thrown when building a new `WasiCtx` instance.
As such, building such an instance should not require the client to
understand different WASI errno values as was assumed until now.
This commit is a first step at streamlining error handling in
`wasi-common` and makes way for the `wiggle` crate.
When adding the `WasiCtxBuilderError`, I've had to do two things of
notable importance:
1. I've removed a couple of `ok_or` calls in `WasiCtxBuilder::build`
and replaced them with `unwrap`s, following the same pattern in
different builder methods above. This is fine since we _always_
operate on non-empty `Option`s in `WasiCtxBuilder` thus `unwrap`ing
will never fail. On the other hand, this might be a good opportunity
to rethink the structure of our builder, and how we good remove
the said `Option`s especially since we always populate them with
empty containers to begin with. I understand this is to make
chaining of builder methods easier which take and return `&mut self`
and the same applies to `WasiCtxBuilder::build(&mut self)` method,
but perhaps it would more cleanly signal the intentions if we simply
moved `WasiCtxBuilder` instance around. Food for thought!
2. Methods specific to determining rights of passed around `std::fs::File`
objects when populating `WasiCtx` `FdEntry` entities now return
`io::Error` directly so that we can reuse them in `WasiCtxBuilder` methods
(returning `WasiCtxBuilderError` error type), and in syscalls
(returning WASI errno).
* Return WasiError directly in syscalls
Also, removes `error::Error` type altogether. Now, `io::Error` and
related are automatically converted to their corresponding WASI
errno value encapsulated as `WasiError`.
While here, it made sense to me to move `WasiError` to `wasi` module
which will align itself well with the upcoming changes introduced
by `wiggle`. To different standard `Result` from WASI specific, I've
created a helper alias `WasiResult` also residing in `wasi` module.
* Update wig
* Add from ffi::NulError and pass context to NotADirectory
* Add dummy commit to test CI
* witx tagged unions: updates to wig to use new semantics
* wig: emit a `#variant: ()` union variant for empty variants
* wasi-common: translate to use tagged unions
* update to flattened layout of event struct
* wig: generate layout tests, and delete bindgen ones
the bindgen tests became out-of-date with the latest changes to the
representation of unions, and the re-jiggering of various struct
definitions that went along with it.
* wasi: point at master with tagged union PR merged
* fix event struct repr on windows
This commit introduces two small changes:
* it adds `gen_errno_strerror` to `wig` crate which generates a
`strerror` function for `__wasi_errno_t` directly from `*.witx`,
similarly to how it's done in the `wasi` crate
* it tweaks `WasiError` type to include the error message generated
with `strerror` when displaying the error
* Add support for wasi_snapshot_preview1.
This adds support for the new ABI, while preserving compatibility
support for the old ABI.
* Fix compilation on platforms where nlink_t isn't 64-bit.
* rustfmt
* Fix Windows build errors.
