* Mark public API functions as unsafe.
This marks the public hostcalls functions as unsafe.
This is generalizing from Rust's `from_raw_fd` function, which is
unsafe. The observation is that nothing prevents code using this
function from passing a bogus or stale dangling file descriptor and
corrupting an arbitrary open stream.
Technically, some of these functions don't use file descriptors, such as
random, clocks, and a few others. However I expect that in the future,
random and clocks will switch to using file descriptors anyway, and it
keeps the macro definitions simpler if we only have to handle one form.
* Mark WasiCtx functions that operate on file descriptors unsafe too.
* `fd_filestat_set_times_impl` doesn't need to be unsafe.
* Remove unnecessary unsafes
Internal modules `memory` and `host` can indeed be internal hidden
behind public-private visibility as `wasmtime-wasi` has already
been updated not to use the said modules (see
CraneStation/wasmtime#298).
Functions which trust that their arguments are valid raw file descriptors
or raw handles should be marked unsafe, because these arguments are
passed unchecked to I/O routines.
* Fix fd_readdir on BSD-style nixes
The fix was tested on Darwin-XNU and FreeBSD. The change introduces
thread-safe cache of (RawFd, *mut libc::DIR) pairs so that
libc::fdopendir syscall is called only once when invoking fd_readdir
for the first time, and then the pointer to the directory stream,
*mut libc::DIR, is reused until the matching raw file descriptor
is closed.
This fix allows then correct use (and matching to the implementation
on Linux kernels) of libc::seekdir and libc::rewinddir to seek through
and rewind the existing directory stream, *mut libc::DIR, which
otherwise seems to be reset/invalidated every time libc::fdopendir
is called (unlike on Linux, where this behaviour is not observed).
* Store dir stream as part of the FdEntry's Descriptor
* Move bsd specifics into separate module
* Add todo comments and fix formatting
* Refactor int conversions
* Emphasise in debug logs that we're looking at fd_readdir entry
* Change visibility of FdEntry and related to public-private
* Rewrite creating DirStream for the first time
* when executed twice in a row, need to manually reset the stream
by calling seekdir with __WASI_DIRCOOKIE_START, if __WASI_DIRCOOKIE_START
was specified
* fix mapping between d_type and __wasi_filetype_t
* include minor refactor - removes use of wasm32 module on the
host's side
This commit adds initial support for [WebAssembly Interface
Types][proposal] to wasmtime. This is all intended to be quite
experimental, so experimental in fact that even the name of the
[proposal] is still in flux. (this has otherwise been known as "host
bindings" or "webidl bindings" or "wasm bindings").
The goal of this commit is to start adding support the wasmtime set of
crates for WebAssembly Interface Types. A new `wasmtime-interface-types`
crate has been added with very basic support for dynamically invoking
and inspecting the various bindings of a module. This is in turn powered
by the `wasm-webidl-bindings` crate which is shared with the
`wasm-bindgen` CLI tool as a producer of this section.
Currently the only integration in `wasmtime`-the-binary itself is that
when passed the `--invoke` argument the CLI will now attempt to invoke
the target function with arguments as parsed from the command line
itself. For example if you export a function like:
fn render(&str) -> String
Then passing `--invoke render` will require one argument on the command
line, which is the first argument as a string, and the return value is
printed to the console. This differs from today's interpretation of
`--invoke` where it is a failure if the invoked function takes more than
one argument and the return values are currently ignored.
This is intended to also be the basis of embedding wasmtime in other
contexts which also want to consume WebAssembly interface types. A
Python extension is also added to this repository which implements the
`wasmtime` package on PyPI. This Python extension is intended to make it
as easy as `pip3 install wasmtime` to load a WebAssembly file with
WebAssembly Interface Types into Python. Extensions for other languages
is of course possible as well!
One of the major missing pieces from this is handling imported functions
with interface bindings. Currently the embedding support doesn't have
much ability to support handling imports ergonomically, so it's intended
that this will be included in a follow-up patch.
[proposal]: https://github.com/webassembly/webidl-bindings
Co-authored-by: Yury Delendik <ydelendik@mozilla.com>
Artur Jamro
Marius Wachtler
Yury Delendik
Jakub Konka
Dan Gohman
Jakub Konka
Marcin Mielniczuk
Sendil Kumar
Alex Crichton