7c67378ab6
* wiggle: copy guest strings from shared memory Along the same lines as #5471, this change adds a new smart pointer, `GuestStrCow`, to copy the string bytes over from Wasm memory to the host when the string is found in shared memory. This is necessary to maintain Rust guarantees: with shared memory, the bytes backing a `GuestStr` could be altered by another thread and this would invalidate the assumption that we can dereference at any point to `&str`. `GuestStrCow` is essentially a wrapper around `GuestStr` when the memory is not shared but copies the memory region into a `String` when the memory is shared. This change updates the uses of Wiggle strings in both wasi-common and wasi-crypto. * review: perform UTF-8 check on `GuestStr` construction
wasi-common
A Bytecode Alliance project
A library providing a common implementation of WASI hostcalls for re-use in any WASI-enabled runtime.
The wasi-common crate will ultimately serve as a library providing a common implementation of
WASI hostcalls for re-use in any WASI (and potentially non-WASI) runtimes
such as Wasmtime and Lucet.
The library is an adaption of lucet-wasi crate from the Lucet project, and it is currently based on 40ae1df git revision.
Please note that the library requires Rust compiler version at least 1.37.0.
Supported syscalls
*nix
In our *nix implementation, we currently support the entire WASI API
with the exception of the proc_raise hostcall, as it is expected to
be dropped entirely from WASI.
Windows
In our Windows implementation, we currently support the minimal subset of WASI API which allows for running the very basic "Hello world!" style WASM apps. More coming shortly, so stay tuned!
Development hints
When testing the crate, you may want to enable and run full wasm32 integration testsuite. This
requires wasm32-wasi target installed which can be done as follows using rustup
rustup target add wasm32-wasi
Now, you should be able to run the integration testsuite by running cargo test on the
test-programs package with test-programs/test_programs feature enabled:
cargo test --features test-programs/test_programs --package test-programs