This commit is a pretty large scale rewrite of the internals of wasm-bindgen. No user-facing changes are expected as a result of this PR, but due to the scale of changes here it's likely inevitable that at least something will break. I'm hoping to get more testing in though before landing!
The purpose of this PR is to update wasm-bindgen to the current state of the interface types proposal. The wasm-bindgen tool was last updated when it was still called "WebIDL bindings" so it's been awhile! All support is now based on https://github.com/bytecodealliance/wasm-interface-types which defines parsers/binary format/writers/etc for wasm-interface types.
This is a pretty massive PR and unfortunately can't really be split up any more afaik. I don't really expect realistic review of all the code here (or commits), but some high-level changes are:
* Interface types now consists of a set of "adapter functions". The IR in wasm-bindgen is modeled the same way not.
* Each adapter function has a list of instructions, and these instructions work at a higher level than wasm itself, for example with strings.
* The wasm-bindgen tool has a suite of instructions which are specific to it and not present in the standard. (like before with webidl bindings)
* The anyref/multi-value transformations are now greatly simplified. They're simply "optimization passes" over adapter functions, removing instructions that are otherwise present. This way we don't have to juggle so much all over the place, and instructions always have the same meaning.
* Add support for #[wasm_bindgen(inspectable)]
This annotation generates a `toJSON` and `toString` implementation for
generated JavaScript classes which display all readable properties
available via the class or its getters
This is useful because wasm-bindgen classes currently serialize to
display one value named `ptr`, which does not model the properties of
the struct in Rust
This annotation addresses rustwasm/wasm-bindgen#1857
* Support console.log for inspectable attr in Nodejs
`#[wasm_bindgen(inspectable)]` now generates an implementation of
`[util.inspect.custom]` for the Node.js target only. This implementation
causes `console.log` and friends to yield the same class-style output,
but with all readable fields of the Rust struct displayed
* Reduce duplication in generated methods
Generated `toString` and `[util.inspect.custom]` methods now call
`toJSON` to reduce duplication
* Store module name in variable
This commit adds support to wasm-bindgen to run over interface
types-enabled modules that use multi-value returns and returns are
loaded from the returned array rather than from memory.
If there's no need for a transformation then there's no need to inject
anything, so make sure that wasm-bindgen with anyref passes enabled
works on non-wasm-bindgen blobs as well.
Closesbytecodealliance/cargo-wasi#16
* adding .vscode folder to .gitignore
* Adding view_mut_raw to generated arrays
* test populating rust vector from JS function
* Uint32Array test, need to make it generic
* Add doc + more test cases
* replacing macro-generated tests with generic test function
it is cleaner, safer and better that way
* improving rustdoc
Using Typescript I have this warning:
`./pkg/index.js
Line 52:22: Expected '!==' and instead saw '!=' eqeqeq
Search for the keywords to learn more about each warning.
To ignore, add // eslint-disable-next-line to the line before.
`
I guess this should solve the warning.
Thank you for all the work.
* autodiscover an exported `main` if possible
this allows for first-class support of binary crates
* wrap `main` to zero out arguments and suppress return value
* add test for bin crate support
* process only the export of the generated main wrapper
* skip most of `export` since only one line of that is needed
This commit switches all of `wasm-bindgen` from the `failure` crate to
`anyhow`. The `anyhow` crate should serve all the purposes that we
previously used `failure` for but has a few advantages:
* It's based on the standard `Error` trait rather than a custom `Fail`
trait, improving ecosystem compatibility.
* We don't need a `#[derive(Fail)]`, which means that's less code to
compile for `wasm-bindgen`. This notably helps the compile time of
`web-sys` itself.
* Using `Result<()>` in `fn main` with `anyhow::Error` produces
human-readable output, so we can use that natively.
* Reduce indentation in interface types processing
Just a small stylistic change
* Update `webidl_ty` field in multi-value transform
When we're emitting a bindings section we need to be sure to update the
listed type of the binding in addition to the actual binding
expressions. This should help remove the stray return pointer being
listed there by accident!
* Wrap the return type of indexing getters as Option<T> if necessary.
* Update tests for indexing getters
* Fix typo
* Add comments describing what the code segment is doing
* Update indexing getter usage
* Revert "Add comments describing what the code segment is doing"
This reverts commit 624a14c0fffb78e8eaed21658ddddbad70b2462d.
* Revert "Fix typo"
This reverts commit 487fc307bc08c2a7778b2117fb03f0f5eb5a3c18.
* Revert "Wrap the return type of indexing getters as Option<T> if necessary."
This reverts commit 547f3dd36c1182928ff728a8452591a492b65e21.
* Update the return signatures of WebIDL indexing getters
This PR contains a few major improvements:
* Code duplication has been removed.
* Everything has been refactored so that the implementation is much easier to understand.
* `future_to_promise` is now implemented with `spawn_local` rather than the other way around (this means `spawn_local` is faster since it doesn't need to create an unneeded `Promise`).
* Both the single threaded and multi threaded executors have been rewritten from scratch:
* They only create 1-2 allocations in Rust per Task, and all of the allocations happen when the Task is created.
* The singlethreaded executor creates 1 Promise per tick, rather than 1 Promise per tick per Task.
* Both executors do *not* create `Closure`s during polling, instead all needed `Closure`s are created ahead of time.
* Both executors now have correct behavior with regard to spurious wakeups and waking up during the call to `poll`.
* Both executors cache the `Waker` so it doesn't need to be recreated all the time.
I believe both executors are now optimal in terms of both Rust and JS performance.
This came up during #1760 where `Promise.resolve` must be invoked with
`this` as the `Promise` object, but we were erroneously importing it in
such a way that it didn't have a shim and `this` was `undefined`.
The threads transform is implicitly enabled nowadays when the memory
looks like it's shared, so ensure that's taken into account in the
`is_enabled` check.
Turns out that `JSON.stringify(undefined)` doesn't actually return a
string, it returns `undefined`! If we're requested to serialize
`undefined` into JSON instead just interpret it as `null` which should
have the expected semantics of serving as a placeholder for `None`.
Closes#1778
To benefit users in debug mode we log any unexpected exceptions to help
diagnose any issues that might arise. It turns out, though, we log this
for *every* exception happening for *every* import, including imports
like `__wbindgen_throw` which are explicitly intended to throw an
exception. This can cause distracting debug logs to get emitted to the
console, so let's squelch the debug logging for known imports that we
shouldn't log for, such as intrinsics.
Closes#1785
This hasn't ever actually worked in `wasm-bindgen` but there's been
enough refactorings since the initial implementation that it's actually
quite trivial to implement now!
Closes#1777
This tiny crate provides utilities for working with Wasm codegen
conventions (typically established by LLVM or lld) such as getting the shadow
stack pointer.
It also de-duplicates all the places in the codebase where we were implementing
these conventions in one-off ways.
This crate provides a transformation to turn exported functions that use a
return pointer into exported functions that use multi-value.
Consider the following function:
```rust
pub extern "C" fn pair(a: u32, b: u32) -> [u32; 2] {
[a, b]
}
```
LLVM will by default compile this down into the following Wasm:
```wasm
(func $pair (param i32 i32 i32)
local.get 0
local.get 2
i32.store offset=4
local.get 0
local.get 1
i32.store)
```
What's happening here is that the function is not directly returning the
pair at all, but instead the first `i32` parameter is a pointer to some
scratch space, and the return value is written into the scratch space. LLVM
does this because it doesn't yet have support for multi-value Wasm, and so
it only knows how to return a single value at a time.
Ideally, with multi-value, what we would like instead is this:
```wasm
(func $pair (param i32 i32) (result i32 i32)
local.get 0
local.get 1)
```
However, that's not what this transformation does at the moment. This
transformation is a little simpler than mutating existing functions to
produce a multi-value result, instead it introduces new functions that wrap
the original function and translate the return pointer to multi-value
results in this wrapper function.
With our running example, we end up with this:
```wasm
;; The original function.
(func $pair (param i32 i32 i32)
local.get 0
local.get 2
i32.store offset=4
local.get 0
local.get 1
i32.store)
(func $pairWrapper (param i32 i32) (result i32 i32)
;; Our return pointer that points to the scratch space we are allocating
;; on the shadow stack for calling `$pair`.
(local i32)
;; Allocate space on the shadow stack for the result.
global.get $shadowStackPointer
i32.const 8
i32.sub
local.tee 2
global.set $shadowStackPointer
;; Call `$pair` with our allocated shadow stack space for its results.
local.get 2
local.get 0
local.get 1
call $pair
;; Copy the return values from the shadow stack to the wasm stack.
local.get 2
i32.load
local.get 2 offset=4
i32.load
;; Finally, restore the shadow stack pointer.
local.get 2
i32.const 8
i32.add
global.set $shadowStackPointer)
```
This `$pairWrapper` function is what we actually end up exporting instead of
`$pair`.
