* Add a first-class way of accessing caller's exports
This commit is a continuation of #1237 and updates the API of `Func` to
allow defining host functions which have easy access to a caller's
memory in particular. The new APIs look like so:
* The `Func::wrap*` family of functions was condensed into one
`Func::wrap` function.
* The ABI layer of conversions in `WasmTy` were removed
* An optional `Caller<'_>` argument can be at the front of all
host-defined functions now.
The old way the wasi bindings looked up memory has been removed and is
now replaced with the `Caller` type. The `Caller` type has a
`get_export` method on it which allows looking up a caller's export by
name, allowing you to get access to the caller's memory easily, and even
during instantiation.
* Add a temporary note
* Move some docs
* Move all examples to a top-level directory
This commit moves all API examples (Rust and C) to a top-level
`examples` directory. This is intended to make it more discoverable and
conventional as to where examples are located. Additionally all examples
are now available in both Rust and C to see how to execute the example
in the language you're familiar with. The intention is that as more
languages are supported we'd add more languages as examples here too.
Each example is also accompanied by either a `*.wat` file which is
parsed as input, or a Rust project in a `wasm` folder which is compiled
as input.
A simple driver crate was also added to `crates/misc` which executes all
the examples on CI, ensuring the C and Rust examples all execute
successfully.
* Move `Func` to its own file
* Support `Func` imports with zero shims
This commit extends the `Func` type in the `wasmtime` crate with static
`wrap*` constructors. The goal of these constructors is to create a
`Func` type which has zero shims associated with it, creating as small
of a layer as possible between wasm code and calling imported Rust code.
This is achieved by creating an `extern "C"` shim function which matches
the ABI of what Cranelift will generate, and then the host function is
passed directly into an `InstanceHandle` to get called later. This also
enables enough inlining opportunities that LLVM will be able to see all
functions and inline everything to the point where your function is
called immediately from wasm, no questions asked.
* Support parsing the text format in `wasmtime` crate
This commit adds support to the `wasmtime::Module` type to parse the
text format. This is often quite convenient to support in testing or
tinkering with the runtime. Additionally the `wat` parser is pretty
lightweight and easy to add to builds, so it's relatively easy for us to
support as well!
The exact manner that this is now supported comes with a few updates to
the existing API:
* A new optional feature of the `wasmtime` crate, `wat`, has been added.
This is enabled by default.
* The `Module::new` API now takes `impl AsRef<[u8]>` instead of just
`&[u8]`, and when the `wat` feature is enabled it will attempt to
interpret it either as a wasm binary or as the text format. Note that
this check is quite cheap since you just check the first byte.
* A `Module::from_file` API was added as a convenience to parse a file
from disk, allowing error messages for `*.wat` files on disk to be a
bit nicer.
* APIs like `Module::new_unchecked` and `Module::validate` remain
unchanged, they require the binary format to be called.
The intention here is to make this as convenient as possible for new
developers of the `wasmtime` crate. By changing the default behavior
though this has ramifications such as, for example, supporting the text
format implicitly through the C API now.
* Handle review comments
* Update more tests to avoid usage of `wat` crate
* Go back to unchecked for now in wasm_module_new
Looks like C# tests rely on this?
* Don't require `Store` in `Instance` constructor
This can be inferred from the `Module` argument. Additionally add a
`store` accessor to an `Instance` in case it's needed to instantiate
another `Module`.
cc #708
* Update more constructors
* Fix a doctest
* Don't ignore store in `wasm_instance_new`
* Run rustfmt
* Remove `HostRef` from the `wasmtime` public API
This commit removes all remaining usages of `HostRef` in the public API
of the `wasmtime` crate. This involved a number of API decisions such
as:
* None of `Func`, `Global`, `Table`, or `Memory` are wrapped in `HostRef`
* All of `Func`, `Global`, `Table`, and `Memory` implement `Clone` now.
* Methods called `type` are renamed to `ty` to avoid typing `r#type`.
* Methods requiring mutability for external items now no longer require
mutability. The mutable reference here is sort of a lie anyway since
the internals are aliased by the underlying module anyway. This
affects:
* `Table::set`
* `Table::grow`
* `Memory::grow`
* `Instance::set_signal_handler`
* The `Val::FuncRef` type is now no longer automatically coerced to
`AnyRef`. This is technically a breaking change which is pretty bad,
but I'm hoping that we can live with this interim state while we sort
out the `AnyRef` story in general.
* The implementation of the C API was refactored and updated in a few
locations to account for these changes:
* Accessing the exports of an instance are now cached to ensure we
always hand out the same `HostRef` values.
* `wasm_*_t` for external values no longer have internal cache,
instead they all wrap `wasm_external_t` and have an unchecked
accessor for the underlying variant (since the type is proof that
it's there). This makes casting back and forth much more trivial.
This is all related to #708 and while there's still more work to be done
in terms of documentation, this is the major bulk of the rest of the
implementation work on #708 I believe.
* More API updates
* Run rustfmt
* Fix a doc test
* More test updates
This commit continues previous work and also #708 by removing the need
to use `HostRef<Module>` in the API of the `wasmtime` crate. The API
changes performed here are:
* The `Module` type is now itself internally reference counted.
* The `Module::store` function now returns the `Store` that was used to
create a `Module`
* Documentation for `Module` and its methods have been expanded.
* Remove the need for `HostRef<Module>`
This commit continues previous work and also #708 by removing the need
to use `HostRef<Module>` in the API of the `wasmtime` crate. The API
changes performed here are:
* The `Module` type is now itself internally reference counted.
* The `Module::store` function now returns the `Store` that was used to
create a `Module`
* Documentation for `Module` and its methods have been expanded.
* Fix compliation of test programs harness
* Fix the python extension
* Update `CodeMemory` to be `Send + Sync`
This commit updates the `CodeMemory` type in wasmtime to be both `Send`
and `Sync` by updating the implementation of `Mmap` to not store raw
pointers. This avoids the need for an `unsafe impl` and leaves the
unsafety as it is currently.
* Fix a typo
* 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 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`.
Several of the examples wrap the Instance in a HostRef, only to
immediately borrow it again to get the exports,and then never touch it
again. Simplify this by owning the Instance directly.
* 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
* Tidy up the `hello` example for `wasmtime`
* Remove the `*.wat` and `*.wasm` files and instead just inline the
`*.wat` into the example.
* Touch up comments so they're not just a repeat of the `println!`
below.
* Move `*.wat` for `memory` example inline
No need to handle auxiliary files with the ability to parse it inline!
* Move `multi.wasm` inline into `multi.rs` example
* Move `*.wasm` for gcd example inline
* Move `*.wat` inline with `import_calling_export` test
* Remove checked in `lightbeam/test.wasm`
Instead move the `*.wat` into the source and parse it into wasm there.
* Run rustfmt
* Migrate from failure to thiserror and anyhow
The failure crate invents its own traits that don't use
std::error::Error (because failure predates certain features added to
Error); this prevents using ? on an error from failure in a function
using Error. The thiserror and anyhow crates integrate with the standard
Error trait instead.
This change does not attempt to semantically change or refactor the
approach to error-handling in any portion of the code, to ensure that
the change remains straightforward to review. Modules using specific
differentiated error types move from failure_derive and derive(Fail) to
thiserror and derive(Error). Modules boxing all errors opaquely move
from failure::Error to anyhow. Modules using String as an error type
continue to do so. Code using unwrap or expect continues to do so.
Drop Display implementations when thiserror can easily derive an
identical instance.
Drop manual traversal of iter_causes; anyhow's Debug instance prints the
chain of causes by default.
Use anyhow's type alias anyhow::Result<T> in place of
std::result::Result<T, anyhow::Error> whenever possible.
* wasm2obj: Simplify error handling using existing messages
handle_module in wasm2obj manually maps
cranelift_codegen::isa::LookupError values to strings, but LookupError
values already have strings that say almost exactly the same thing.
Rely on the strings from cranelift.
* wasmtime: Rely on question-mark-in-main
The main() wrapper around rmain() completely matches the behavior of
question-mark-in-main (print error to stderr and return 1), so switch to
question-mark-in-main.
* Update to walrus 0.13 and wasm-webidl-bindings 0.6
Both crates switched from failure to anyhow; updating lets us avoid a
translation from failure to anyhow within wasmtime-interface-types.
Alex Crichton
Yury Delendik
Josh Triplett
Dan Gohman