This commit switches strategies for storing `JsValue` from a heap/stack
to just one heap. This mirrors the new strategy for `JsValue` storage
in #1002 and should make multiplexing those strategies at
`wasm-bindgen`-time much easier.
Instead of having one array which acts as a stack for borrowed values
and one array for a heap of borrowed values, only one JS array is used
for storage of JS values now. This makes `getObject` far simpler by
simply being an array access, but it means that cloning an object now
reserves a new slot instead of reference counting it. If the old
reference counting behavior is needed it's thought that `Rc<JsValue>`
can be used in Rust.
The new "heap" has an initial stack pointer which grows downwards, and a
heap which grows upwards. The heap is a singly-linked-list which is
allocated/deallocated from. The stack grows downwards to zero and
presumably starts generating errors once it underflows. An initial stack
size of 32 is chosen as that should encompass all use cases today, but
we can eventually probably add configuration for this!
Note that the heap is initialized to all `null` for the stack and then
the initial JS values (`undefined`, `null`, `true`, `false`) are pushed
onto the heap in reserved locations.
Currently closure shims are communicated to JS at runtime, although at
runtime the same constant value is always passed to JS! More pressing,
however, work in #1002 requires knowledge of closure descriptor indices
at `wasm-bindgen` time which is not currently known.
Since the closure descriptor shims and such are already constant values,
this commit moves the descriptor function indices into the *descriptor*
for a closure/function pointer. This way we can learn about these values
at `wasm-bindgen` time instead of only knowing them at runtime.
This should have no semantic change on users of `wasm-bindgen`, although
some closure invocations may be slightly speedier because there's less
arguments being transferred over the boundary. Overall though this will
help #1002 as the closure shims that the Rust compiler generates may not
be the exact ones we hand out to JS, but rather wrappers around them
which do `anyref` business things.
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!
While technically correct the current implementation sort of made it
only roundaboutedly so. Tweak the logic a bit and the associated comment
to ensure that stack values are never dropped and the global constants
are all skipped.
... and add a parallel raytracing demo!
This commit adds enough support to `wasm-bindgen` to produce a workable
wasm binary *today* with the experimental WebAssembly threads support
implemented in Firefox Nightly. I've tried to comment what's going on in
the commits and such, but at a high level the changes made here are:
* A new transformation, living in a new `wasm-bindgen-threads-xform`
crate, prepares a wasm module for parallel execution. This performs a
number of mundane tasks which I hope to detail in a blog post later on.
* The `--no-modules` output is enhanced with more support for when
shared memory is enabled, allowing passing in the module/memory to
initialize the wasm instance on multiple threads (sharing both module
and memory).
* The `wasm-bindgen` crate now offers the ability, in `--no-modules`
mode, to get a handle on the `WebAssembly.Module` instance.
* The example itself requires Xargo to recompile the standard library
with atomics and an experimental feature enabled. Afterwards it
experimentally also enables threading support in wasm-bindgen.
I've also added hopefully enough CI support to compile this example in a
builder so we can upload it and poke around live online. I hope to
detail more about the technical details here in a blog post soon as
well!
The `JsValue` type wraps a slab/heap of js objects which is managed by
the wasm-bindgen shim, and everything here is not actually able to cross
any thread boundaries. When wasm actually has threads, for example, each
thread will have to have its own slab of objects generated by
wasm-bindgen, and indices in one slab aren't valid in any other slabs.
This is technically a breaking change because `JsValue` was previously
`Send` and `Sync`, but I'm hoping that in practice this isn't actually a
breaking change because nothing in wasm can be using threads which in
theory shouldn't activate the `Send` and/or `Sync` bounds.
Adding `#[inline]` will typically improve codegen for optimized builds
without LTO (so far the majority in practice) by allowing functions that
otherwise couldn't be inlined across codegen units to get inlined
across codegen units.
Right now `wasm-bindgen` has a lot of functions that are very small and
delegate to other functions, but aren't otherwise candidates for
inlining because they're concrete.
I was poking around in release-mode wasm recently and noticed an
alarming number of functions for tiny pieces of functionality, which
motivates this patch!
This commit improves the codegen for `Closure<T>`, primarily for ZST
where the closure doesn't actually capture anything. Previously
`wasm-bindgen` would unconditionally allocate an `Rc` for a fat pointer,
meaning that it would always hit the allocator even when the `Box<T>`
didn't actually contain an allocation. Now the reference count for the
closure is stored on the JS object rather than in Rust.
Some more advanced tests were added along the way to ensure that
functionality didn't regress, and otherwise the calling convention for
`Closure` changed a good deal but should still be the same user-facing.
The primary change was that the reference count reaching zero may cause
JS to need to run the destructor. It simply returns this information in
`Drop for Closure` and otherwise when calling it now also retains a
function pointer that runs the destructor.
Closes#874
Previously the `link_mem_intrinsics` hack actually had a runtime
overhead by storing a value into a global location, but it turns out we
can actually use a non-inlined function call as part of the *descriptor*
which requires this to be in the final binary, but we'll end up snip'ing
the value at the end.
All in all this should mean that it's not a zero-overhead solution for
linking these intrinsics! The `#[wasm_bindgen]` attribute already has
other problems if the descriptors don't show up, so that's the least of
our issues!
This commit implements support for binding APIs that take
`Uint8ClampedArray` in JS. This is pretty rare but comes up in a
`web-sys` binding or two, and we're now able to bind these APIs instead
of having to omit the bindings.
The `Uint8ClampedArray` type is bound by using the `Clamped` marker
struct in Rust. For example this is declaring a JS API that takes
`Uint8ClampedArray`:
use wasm_bindgen::Clamped;
#[wasm_bindgen]
extern {
fn takes_clamped(a: Clamped<&[u8]>);
}
The `Clamped` type currently only works when wrapping the `&[u8]`, `&mut
[u8]`, and `Vec<u8>` types. Everything else will produce an error at
`wasm-bindgen` time.
Closes#421
This commit adds support for exporting a function defined in Rust that returns a
`Result`, translating the `Ok` variant to the actual return value and the `Err`
variant to an exception that's thrown in JS.
The support for return types and descriptors was rejiggered a bit to be a bit
more abstract and more well suited for this purpose. We no longer distinguish
between functions with a return value and those without a return value.
Additionally a new trait, `ReturnWasmAbi`, is used for converting return values.
This trait is an internal implementation detail, however, and shouldn't surface
itself to users much (if at all).
Closes#841
This commit adds an implementation of `AsRef<JsValue>` for the `Closure<T>`
type. Previously this was not possible because the `JsValue` didn't actually
exist until the closure was passed to JS, but the implementation has been
changed to ... something a bit more unconventional. The end result, however, is
that `Closure<T>` now always contains a `JsValue`.
The end result of this work is intended to be a precursor to binding callbacks
in `web-sys` as `JsValue` everywhere but still allowing usage with `Closure<T>`.
In addition to closing #495 this'll be useful eventually when instantiating
multiple wasm modules from Rust as you'd now be able to acquire a reference to
the current module in Rust itself.
I discussed this with @fitzgen awhile back and this sort of casting seems
especially problematic when you have code along the lines of:
let mut x: HtmlElement = ...;
{
let y: &mut JsValue = x.as_ref();
*y = 3.into();
}
x.some_html_element_method();
as that will immediately throw! We didn't have a use case for mutable casting
other than consistency, so this commit removes it for now. We can possibly add
it back in later if motivated, but for now it seems reasonable to try to avoid
these sorts of pitfalls!
This commit adds support for generating bindings for dictionaries defined in
WebIDL. Dictionaries are associative arrays which are simply objects in JS with
named keys and some values. In Rust given a dictionary like:
dictionary Foo {
long field;
};
we'll generate a struct like:
pub struct Foo {
obj: js_sys::Object,
}
impl Foo {
pub fn new() -> Foo { /* make a blank object */ }
pub fn field(&mut self, val: i32) -> &mut Self {
// set the field using `js_sys::Reflect`
}
}
// plus a bunch of AsRef, From, and wasm abi impls
At the same time this adds support for partial dictionaries and dictionary
inheritance. All dictionary fields are optional by default and hence only have
builder-style setters, but dictionaries can also have required fields. Required
fields are exposed as arguments to the `new` constructor.
Closes#241
* Bump to 0.2.12
* Update all version numbers and deps
* Update all listed authors to `["The wasm-bindgen Developers"]`
* Update `repository` links to specific paths for each crate
* Update `homepage` links to the online book
* Update all links away from `alexcrichton/wasm-bindgen`
* Add `#[doc]` directives for HTML URLs
* Update more version requirements
* Fill out CHANGELOG
* Shard the `convert.rs` module into sub-modules
Hopefully this'll make the organization a little nicer over time!
* Start adding support for optional types
This commit starts adding support for optional types to wasm-bindgen as
arguments/return values to functions. The strategy here is to add two new
traits, `OptionIntoWasmAbi` and `OptionFromWasmAbi`. These two traits are used
as a blanket impl to implement `IntoWasmAbi` and `FromWasmAbi` for `Option<T>`.
Some consequences of this design:
* It should be possible to ensure `Option<SomeForeignType>` implements to/from
wasm traits. This is because the option-based traits can be implemented for
foreign types.
* A specialized implementation is possible for all types, so there's no need for
`Option<T>` to introduce unnecessary overhead.
* Two new traits is a bit unforutnate but I can't currently think of an
alternative design that works for the above two constraints, although it
doesn't mean one doesn't exist!
* The error messages for "can't use this type here" is actually halfway decent
because it says these new traits need to be implemented, which provides a good
place to document and talk about what's going on here!
* Nested references like `Option<&T>` can't implement `FromWasmAbi`. This means
that you can't define a function in Rust which takes `Option<&str>`. It may be
possible to do this one day but it'll likely require more trait trickery than
I'm capable of right now.
* Add support for optional slices
This commit adds support for optional slice types, things like strings and
arrays. The null representation of these has a pointer value of 0, which should
never happen in normal Rust. Otherwise the various plumbing is done throughout
the tooling to enable these types in all locations.
* Fix `takeObject` on global sentinels
These don't have a reference count as they're always expected to work, so avoid
actually dropping a reference on them.
* Remove some no longer needed bindings
* Add support for optional anyref types
This commit adds support for optional imported class types. Each type imported
with `#[wasm_bindgen]` automatically implements the relevant traits and now
supports `Option<Foo>` in various argument/return positions.
* Fix building without the `std` feature
* Actually fix the build...
* Add support for optional types to WebIDL
Closes#502
* Move the `js` module to a `js_sys` crate
* Update js-sys tests to pass again
* Update binding_to_unimplemented_apis_doesnt_break_everything
Remove its dependency on the `js` module
* Update metadata for js-sys
* Fix the `closures` example
I've started noticing this in non-LTO builds and initially tried to remove it. I
was unsuccessful but decided to better document my adventures to hopefully
improve future onlookers!
* Create a new `web-sys` crate
This will eventually contain all the WebIDL-generated bindings to Web APIs.
* ci: Test the new `web-sys` crate in CI
* web-sys: Add a small README
* web-sys: Vendor all the WebIDL files from mozilla-central
* backend: Add a pass to remove AST items that use undefined imports
This is necessary for the WebIDL frontend, which can't translate many WebIDL
constructs into equivalent wasm-bindgen AST things yet. It lets us make
incremental progress: we can generate bindings to methods we can support right
now even though there might be methods on the same interface that we can't
support yet.
* webidl: Add a bunch of missing semicolons
* webidl: Make parsing private
It was only `pub` so that we could test it, but we ended up moving towards
integration tests rather than unit tests that assert particular ASTs are parsed
from WebIDL files.
* webidl: Remove uses of undefined import types
* test-project-builder: Build projects in "very verbose" mode
This helps for debugging failing WebIDL-related tests.
* test-project-builder: Add more profiling timers
* test-project-builder: Detect when webpack-dev-server fails
Instead of going into an infinite loop, detect when webpack-dev-server fails to
start up and early exit the test.
* webidl: Specify version for dev-dependency on wasm-bindgen-backend
Instead of only a relative path.
* guide: Add section about contributing to `web-sys`
* WIP enable Event.webidl
Still need to fix and finish the test.
* Update expected webidl output
* Start out a test's status as incomplete
That way if we don't fill it in the error message doesn't look quite so bizarre
* Fix onerror function in headless mode
Otherwise we don't see any output!
* Fix package.json/node_modules handling in project generation
Make sure these are looked up in the git project root rather than the crate root
* Avoid logging body text
This was meant for debugging and is otherwise pretty noisy
* Fix a relative path
* More expected test fixes
* Fix a typo
* test-project-builder: Allow asynchronous tests
* webidl: Convert [Unforgeable] attributes into `#[wasm_bindgen(structural)]`
Fixes#432
* test-project-builder: Print generated WebIDL bindings for debugging purposes
Helps debug bad WebIDL bindings generation inside tests.
* When we can't find a descriptor, say which one can't be found
This helps when debugging things that need to become structural.
* web-sys: Test bindings for Event
* ci: Use `--manifest-path dir` instead of `cd dir && ...`
* web-sys: Just move .webidl files isntead of symlinking to enable them
* tests: Polyfill Array.prototype.values for older browsers in CI
* test-project-builder: Don't panic on poisoned headless test mutex
We only use it to serialize headless tests so that we don't try to bind the port
concurrently. Its OK to run another headless test if an earlier one panicked.
* JsValue: Add {is,as}_{object,function} methods
Allows dynamically casting values to `js::Object` and `js::Function`.
* tidy: Fix whitespace and missing semicolons
* Allow for dynamic feature detection of methods
If we create bindings to a method that doesn't exist in this implementation,
then it shouldn't fail until if/when we actually try and invoke that missing
method.
* tests: Do feature detection in Array.prototype.values test
* Add JsValue::{is_string, as_js_string} methods
And document all the cast/convert/check methods for js value.
* eslint: allow backtick string literals
* Only generate a fallback import function for non-structural imports
These are bindings to JavaScript's standard, built-in objects and their methods
and properties.
This does *not* include any Web, Node, or any other JS environment APIs. Only
the things that are guaranteed to exist in the global scope by the ECMAScript
standard.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects
This commit optimizes constructing an instance of `JsValue` which is one of
`null`, `undefined`, `true`, or `false`. These are commonly created on the Rust
side of things and since there's only a limited set of values we can easily
prepopulate the global slab with a few entries and use hardcoded indices to
refer to these constants. This should avoid the need to travel into JS to insert
a `null` or and `undefined` into the global slab.
Currently `#[wasm_bindgen]` generates a bunch of references to symbols that
don't actually exist on non-wasm targets, making it more difficult to get a
crate working across multiple platforms. This commit updates the symbol
references to be dummy ones that panic on non-wasm targets to allow simple
testing/benchmarking to work on native targets.
While this isn't a perfect solution for #114 it's probably as good as we can do
for now pending upstream Cargo features, so I'm gonna say that it...
Closes#114
These functions are activated with the `serde-serialization` feature of the
`wasm-bindgen` crate. When activated they will allow passing any arbitrary value
into JS that implements the `Serialize` trait and receiving any value from JS
using the `Deserialize` trait. The interchange between JS and Rust is JSON.
Closes#96
