Recently proposed in WebAssembly/tool-conventions#65 each wasm file will
now have an optional `producers` section listing the tooling that went
into producing it. Let's add `wasm-bindgen` in when it processes a wasm
file!
Correction to Pull Request #1035
limira is correct, that particular paragraph is referencing another crate. Considering the wasm-bindgen tutorial links here for the web-sys crate I added another link to the correct cargo link.
Sorry for the mistake.
This commit adds an optimization to `wasm-bindgen` to directly import
and invoke other modules' functions from the wasm module, rather than
going through a shim in the imported bindings. This will be an important
optimization in the future for the host bindings proposal, but for now
it's largely just a proof-of-concept to show that we can do it and is
unlikely to bring about many performance benefits.
The implementation in this commit is largely refactoring to reorganize a
bit how functions are imported, but the implementation happens in
`generate_import_function`.
With this commit, 71/287 imports in the `tests/wasm/main.rs` suite get
hooked up directly to the ES modules, no shims needed!
When returning a ptr/length for allocations and such wasm-bindgen's
generated JS would previously return an array with two elements. It
turns out this doesn't optimize well in all engines! (See #1031). It
looks like we can optimize the array destructuring a bit more, but this
is all generated code which doesn't need to be too readable so we can
also remove the temporary allocation entirely and just pass the second
element of this array through a global instead of the return value.
Closes#1031
This commit updates the `__wbindgen_malloc` shim to avoid throwing a
descriptive error in release mode. This is primarily done for two
reasons:
* If the function is gc'd out in release mode the `"invalid malloc
request"` string is part of data and can't be gc'd automatically.
* In some esoteric JS environments `TextDecoder` isn't always available,
and this relatively core function is very quick to bring in that
requirement early on. For example some recent experimentation with
WebAudio worklets shows that they currently don't have the
`TextDecoder` type available!
This fixes a mistake in allowing a `WebAssembly.Module` to be passed to
the initialization function in `--no-modules` mode by ensuring that it
resolves to a map of an instance/module instead of just resolving to an
instance.
This commit adds a `--remove-name-section` flag to the `wasm-bindgen`
command which will remove the `name` section of the wasm file, used to
indicate the names of functions typically used in debugging. This flag
is off-by-default and will primarily be controlled by wasm-pack,
typically being passed by default with `wasm-pack build --release`.
Closes#1021
This commit switches all imports of JS methods to `structural` by
default. Proposed in [RFC 5] this should increase the performance of
bindings today while also providing future-proofing for possible
confusion with the recent addition of the `Deref` trait for all imported
types by default as well.
A new attribute, `host_binding`, is introduced in this PR as well to
recover the old behavior of binding directly to an imported function
which will one day be the precise function on the prototype. Eventually
`web-sys` will switcsh over entirely to being driven via `host_binding`
methods, but for now it's been measured to be not quite as fast so we're
not making that switch yet.
Note that `host_binding` differs from the proposed name of `final` due
to the controversy, and its hoped that `host_binding` is a good
middle-ground!
[RFC 5]: https://rustwasm.github.io/rfcs/005-structural-and-deref.html
This commit removes shims, where possible, for `structural` items.
Instead of generating code that looks like:
const target = function() { this.foo(); };
exports.__wbg_thing = function(a) { target.call(getObject(a)); };
we now instead generate:
exports.__wbg_thing = function(a) { getObject(a).foo(); };
Note that this only applies to `structural` bindings, all default
bindings (as of this commit) are still using imported targets to ensure
that their binding can't change after instantiation.
This change was [detailed in RFC #5][link] as an important optimization
for `structural` bindings to ensure they've got performance parity with
today's non-`structural` default bindings.
[link]: https://rustwasm.github.io/rfcs/005-structural-and-deref.html#why-is-it-ok-to-make-structural-the-default
Previously `arguments` was used to pass around an array of arguments,
but this wasn't actually a `js_sys::Array` but rather a somewhat
esoteric internal object. When switching over `Array` methods to be
`structural` this caused issues because the inherent methods on an
`arguments` object were different than that of `js_sys::Array`.
This commit implements the first half of [RFC #5] where the `Deref`
trait is implemented for all imported types. The target of `Deref` is
either the first entry of the list of `extends` attribute or `JsValue`.
All examples using `.as_ref()` with various `web-sys` types have been
updated to the more ergonomic deref casts now. Additionally the
`web-sys` generation of the `extends` array has been fixed slightly to
explicitly list implementatoins in the hierarchy order to ensure the
correct target for `Deref` is chosen.
[RFC #5]: https://github.com/rustwasm/rfcs/blob/master/text/005-structural-and-deref.md
