* a certain subset of io::Errors are expected - these we have
a (platform-specific, because windows) method to translate into
one of the wasi errno variants in the Error enum.
* some io::Errors are unexpected - wasi-common doesnt expect them from
the underlying OS. rather than preserve any fidelity in reporting
those to the user (only the unix impl attempts this), lets collect
those as an `Error::UnexpectedIo(#[source] std::io::Error)`.
Rather than trace at the conversion site, we rely on the wiggle error
conversion hooks to trace the `Error`'s `Debug` impl, and then
we convert all of these unexpected into `Errno::Io` for returning
to the guest.
This is a different behavior from before, and I don't have any firm
guarantees that nobody was depending on the old behavior, but it
appears to me that none of those unexpected errnos were reasonable
to expect from any of the filesystem syscalls wasi-common is making.
this is a bug - the TODO was never resolved, even when the code to
implement it was added right below :)
tracing is already in the transitive deps via wiggle, so no extra
trouble there. tracing::debug is more appropriate than eprintln
tracing is already the dep that wiggle uses.
I used tracing structured arguments wherever I could, but I skipped over
it in all of the snapshot_0 code, because I'm going to delete that code
and replace it with wiggle-based stuff real soon.
* virtfs file: update cursor position on fd_read
If a handle is backed by InMemoryFile, fd_read (turned into
Handle::read_vectored) doesn't update the cursor position properly and
thus prevents the caller from detecting EOF.
* virtfs file: fd_{pread,pwrite}: update offset in iovec iteration
If multiple iovec's are supplied, fd_pread and fd_pwrite previously
access data at the same offset for each iovec.
* Use AsRef<Path> instead of AsRef<OsStr> in yanix functions.
`AsRef<Path>` makes these more consistent with `std` interfaces, making
them easier to use outside of wasi-common.
Also, refactor the conversion to `CString` into a helper function.
* Reduce clutter from fully-qualifying names.
* rustfmt
* The underlying `R`/`W` doesnt need to be Clone, since we just need to
clone the Arc it sits behind.
* The rights actually shouldn't be behind an Arc - those get mutated
separately in each clone.
* Rename `OFlag`/`AtFlag` to `OFlags`/`AtFlags`.
This makes them consistent with `PollFlags` and common usage of
bitflags types in Rust code in general.
POSIX does tend to use names like `oflag` and `flag`, so this is in mild
disagreement with POSIX style, however I find this particular aspects of
POSIX confusing because these values hold multiple flags.
* rustfmt
This introduces `Handle` implementations for readable and writable pipes, backed by arbitrary `Read`
and `Write` types, respectively. In particular, this allows for easily providing, capturing, or
redirecting WASI stdio without having to resort to OS-provided file descriptors.
The implementation is based heavily on `wasi_common::virtfs::InMemoryFile`, but without inapplicable
operations like `seek` or `allocate`.
Note that these types are not 1:1 replacements for real pipes, because they do not support `poll_oneoff`.
* This PR is against a branch called `main`
* Internally all docs/CI/etc is updated
* The default branch of the repo is now `main`
* All active PRs have been updated to retarget `main`
Closes#1914
If stdio is not inherited nor associated with a file, WasiCtxBuilder
tries to open "/dev/null" ("NUL" on Windows) and attach stdio to it.
While most platforms today support those device files, it would be
good to avoid unnecessary access to the host device if possible. This
patch instead uses a virtual Handle that emulates the "NUL" device.
* Allow any type which implements Handle to act as stdio
There have been requests to allow more than just raw OS handles to
act as stdio in `wasi-common`. This commit makes this possible by
loosening the requirement of the `WasiCtxBuilder` to accept any
type `T: Handle + 'static` to act as any of the stdio handles.
A couple words about correctness of this approach. Currently, since
we only have a single `Handle` super-trait to represent all possible
WASI handle types (files, dirs, stdio, pipes, virtual, etc.), it
is possible to pass in any type to act as stdio which can be wrong.
However, I envision this being a problem only in the near(est) future
until we work out how to split `Handle` into several traits, each
representing a different type of WASI resource. In this particular
case, this would be a resource which would implement the interface
required for a handle to act as a stdio (with appropriate rights, etc.).
* Use OsFile in c-api
* Add some documention to the types exposed by this PR, and a few others
Signed-off-by: Jakub Konka <kubkon@jakubkonka.com>
* Add construction examples and missing docs for Handle trait
* Fix example on Windows
* Merge wasi_preview_builder into create_preview1_instance
Co-authored-by: Pat Hickey <pat@moreproductive.org>
* Reactor support.
This implements the new WASI ABI described here:
https://github.com/WebAssembly/WASI/blob/master/design/application-abi.md
It adds APIs to `Instance` and `Linker` with support for running
WASI programs, and also simplifies the process of instantiating
WASI API modules.
This currently only includes Rust API support.
* Add comments and fix a typo in a comment.
* Fix a rustdoc warning.
* Tidy an unneeded `mut`.
* Factor out instance initialization with `NewInstance`.
This also separates instantiation from initialization in a manner
similar to https://github.com/bytecodealliance/lucet/pull/506.
* Update fuzzing oracles for the API changes.
* Remove `wasi_linker` and clarify that Commands/Reactors aren't connected to WASI.
* Move Command/Reactor semantics into the Linker.
* C API support.
* Fix fuzzer build.
* Update usage syntax from "::" to "=".
* Remove `NewInstance` and `start()`.
* Elaborate on Commands and Reactors and add a spec link.
* Add more comments.
* Fix wat syntax.
* Fix wat.
* Use the `Debug` formatter to format an anyhow::Error.
* Fix wat.
The documentation for RtlNtStatusToDosError explicitly tells to call
it via GetProcAddress. The documentation for NtQueryInformationFile
does not, but similar considerations apply because there is normally
no import library for ntdll.
The main reason to use GetProcAddress though is because MinGW does
include an import library for ntdll, this import library contains
a definition of setjmp, and because of the way rustc orders linker
arguments, this definition of setjmp conflicts with and gets picked
over the one in msvcrt. Using setjmp from ntdll is undesirable as it
is an undocumented API and it is missing from wine, making it harder
to develop wasmtime using a cross-compiler.
Fixes#1738.
