If write doesn't write the full buffer, start the next write at the
point where the write left off.
Also, usize `ssize_t` for the return types of `read` and `write`.
* Update rust embed example (#967)
Ensures that the example works with the current API.
Drops mention of HostRef as the example is complete without it.
* Cleanup
The `wasmtime` release procees seems like it's been a bit ad-hoc up to
this point, so I figured it'd be good to try to document what we do
today and codify what should be done as well as a form of release
checklist.
I've noticed that we have a number of releases (like v0.11.0) but the
`Cargo.toml` files in the repository don't reflect the current version
of `wasmtime`. Additionally I've noticed that the [most recent release]
ended up having failed tests because `Cargo.toml` was modified but
`Cargo.lock` wasn't updated. I'm hoping that by having a checklist we
can avoid these sorts of accidental issues in the future!
[release]: https://github.com/bytecodealliance/wasmtime/runs/434690272
* Remove the need for `HostRef<Store>`
This commit goes through the public API of the `wasmtime` crate and
removes the need for `HostRef<Store>`, as discussed in #708. This commit
is accompanied with a few changes:
* The `Store` type now also implements `Default`, creating a new
`Engine` with default settings and returning that.
* The `Store` type now implements `Clone`, and is documented as being a
"cheap clone" aka being reference counted. As before there is no
supported way to create a deep clone of a `Store`.
* All APIs take/return `&Store` or `Store` instead of `HostRef<Store>`,
and `HostRef<T>` is left as purely a detail of the C API.
* The `global_exports` function is tagged as `#[doc(hidden)]` for now
while we await its removal.
* The `Store` type is not yet `Send` nor `Sync` due to the usage of
`global_exports`, but it is intended to become so eventually.
* Touch up comments on some examples
* Run rustfmt
This commit refactors the Wasmtime CLI tools to use `structopt` instead of
`docopt`.
The `wasmtime` tool now has the following subcommands:
* `config new` - creates a new Wasmtime configuration file.
* `run` - runs a WebAssembly module.
* `wasm2obj` - translates a Wasm module to native object file.
* `wast` - runs a test script file.
If no subcommand is specified, the `run` subcommand is used. Thus,
`wasmtime foo.wasm` should continue to function as expected.
The `wasm2obj` and `wast` tools still exist, but delegate to the same
implementation as the `wasmtime` subcommands. The standalone `wasm2obj` and
`wast` tools may be removed in the future in favor of simply using `wasmtime`.
Included in this commit is a breaking change to the default Wasmtime
configuration file: it has been renamed from `wasmtime-cache-config.toml` to
simply `config.toml`. The new name is less specific which will allow for
additional (non-cache-related) settings in the future.
There are some breaking changes to improve command line UX:
* The `--cache-config` option has been renamed to `--config`.
* The `--create-config-file` option has moved to the `config new` subcommand.
As a result, the `wasm2obj` and `wast` tools cannot be used to create a new
config file.
* The short form of the `--optimize` option has changed from
`-o` to `-O` for consistency.
* The `wasm2obj` command takes the output object file as a
required positional argument rather than the former required output *option*
(e.g. `wasmtime wasm2obj foo.wasm foo.obj`).
This commit removes the need to use `HostRef<Engine>` in the Rust API.
Usage is retained in the C API in one location, but otherwise `Engine`
can always be used directly.
This is the first step of progress on #708 for the `Engine` type.
Changes here include:
* `Engine` is now `Clone`, and is documented as being cheap. It's not
intended that cloning an engine creates a deep copy.
* `Engine` is now both `Send` and `Sync`, and asserted to be so.
* Usage of `Engine` in APIs no longer requires or uses `HostRef`.
While the wasm file has only one export, our introduction should set a
good example for how to find functions even for wasm files that have
multiple exports. Find the answer function by name rather than assuming
index 0.
Minor variable name change to avoid having to wrap the line.
* Rename the `wasmtime_api` library to match the containing `wasmtime` crate
Commit d9ca508f80 renamed the
`wasmtime-api` crate to `wasmtime`, but left the name of the library it
contains as `wasmtime_api`.
It's fairly unusual for a crate to contain a library with a different
name, and it results in rather confusing error messages for a user; if
you list `wasmtime = "0.7"` in `Cargo.toml`, you can't `use
wasmtime::*`, you have to `use wasmtime_api::*;`.
Rename the `wasmtime_api` library to `wasmtime`.
* Stop renaming wasmtime to api on imports
Various users renamed the crate formerly known as wasmtime_api to api,
and then used api:: prefixes everywhere; change those all to wasmtime::
and drop the renaming.
* Migrate back to `std::` stylistically
This commit moves away from idioms such as `alloc::` and `core::` as
imports of standard data structures and types. Instead it migrates all
crates to uniformly use `std::` for importing standard data structures
and types. This also removes the `std` and `core` features from all
crates to and removes any conditional checking for `feature = "std"`
All of this support was previously added in #407 in an effort to make
wasmtime/cranelift "`no_std` compatible". Unfortunately though this
change comes at a cost:
* The usage of `alloc` and `core` isn't idiomatic. Especially trying to
dual between types like `HashMap` from `std` as well as from
`hashbrown` causes imports to be surprising in some cases.
* Unfortunately there was no CI check that crates were `no_std`, so none
of them actually were. Many crates still imported from `std` or
depended on crates that used `std`.
It's important to note, however, that **this does not mean that wasmtime
will not run in embedded environments**. The style of the code today and
idioms aren't ready in Rust to support this degree of multiplexing and
makes it somewhat difficult to keep up with the style of `wasmtime`.
Instead it's intended that embedded runtime support will be added as
necessary. Currently only `std` is necessary to build `wasmtime`, and
platforms that natively need to execute `wasmtime` will need to use a
Rust target that supports `std`. Note though that not all of `std` needs
to be supported, but instead much of it could be configured off to
return errors, and `wasmtime` would be configured to gracefully handle
errors.
The goal of this PR is to move `wasmtime` back to idiomatic usage of
features/`std`/imports/etc and help development in the short-term.
Long-term when platform concerns arise (if any) they can be addressed by
moving back to `no_std` crates (but fixing the issues mentioned above)
or ensuring that the target in Rust has `std` available.
* Start filling out platform support doc
* Cover `cargo wasi`
* Cover a "Hello, world!" binary
* Cover a "Hello, world!" library
* Cover a more advanced example with WebAssembly interface types
* Importing/exporting functionality basics
* Update the top-level README.md and embedding documentation.
wasmtime-api is now the primary external API crate, so recommend that
instead of wasmtime-jit.
Also, enable wasmtime-api's C API by default, so that it shows up on
docs.rs, and to make it easier to use.
And, add basic embedding documentation and link to it from the
README.md. Credit to @yurydelendik for the content.
* Use the new wasm-c-api URL.
* Don't pass --features wasm-c-api, as it is now on by default.
This commit adds the skeleton of a new set of documentation for
`wasmtime` in the existing `docs` directory. This documentation is
organized and compiled with [mdbook] which the Rust project uses for
most of its own documentation as well. At a previous meeting we
brainstormed a rough skeleton of what the documentation in this book
would look like, and I've transcribed that here for an example of how
this is rendered and how it can be laid out. No actual documentation is
written yet.
This commit also additionally adds necessary support to auto-publish
both this book documentation and API documentation every time a commit
is pushed to the `master` branch. All HTML will be automatically pushed
to the `gh-pages` branch so long as the CI passes, and this should get
deployed to https://cranestation.github.io/wasmtime.
I've done a few dry-runs and I think this'll all work, but we'll likely
tweak a few things here and there after running this through CI to make
sure everything looks just as we'd like. My hope though is that after
this lands we can start actually filling out all the documentation and
being able to review it as well.
[mdbook]: https://crates.io/crates/mdbook
I thought it might be useful for future WASI users to have the WASI tutorial written not only in C but also in Rust.
I'm also happy to keep the tutorial up to date with the current state of WASI target in Rust.
Document that `setjmp`/`longjmp` and C++ exceptions are unsupported, and
update the documentation about the function signature mismatch bug to
reflect that it's now just a warning rather than a fatal error.
