This is a bit of a refinement of the solution from #548 to make sure that these
statics are only present on the `wasm32-*` targets, as otherwise these
descriptors are completely inert on other platforms!
* 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
Not a lot of attention has been paid to dealing with conflicts of symbols
between crates and different `#[wasm_bindgen]` blocks. This commit starts to fix
this issue by unblocking #486 which first ran into this. Currently there's a bug
where if two independent crates bind the same JS API they'll generate the same
symbol which causes conflicts for things like LTO or linking in general.
This commit starts to add a "salt" to all symbols generated by `wasm-bindgen`
(these are all transparent to the user) to ensure that each crate's invocations
are kept apart from one another and using the correct bindings.
* clippy: it is more idiomatic to loop over references to containers instead of using explicit iteration methods
* clippy: useless use of `format!`
* clippy: if/else is an expression
* clippy: use of followed by a function call
* clippy: large size difference between variants
* clippy: redundant closure
* Revert "clippy: large size difference between variants"
This reverts commit 7e2e660dd47c9718126d1c45ae1caa632e287a14.
* Revert "clippy: it is more idiomatic to loop over references to containers instead of using explicit iteration methods"
This reverts commit 5c4804f790fc6a33a7a0f0d2aacdc4b98529b978.
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!
* remove BindgenAttrs from other backend::ast structs
This is primarily a tool for use with the macro crate. Most of
these attributes were ignored in the actual codegen, but a few
were still being used. This is confusing when trying to add
other sources for codegen (such as webidl and typescript).
* move parsing logic to macro crate
This makes the backend crate solely concerned with having an ast
for which we can generate code.
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
The previous codegen wasn't enough to convince LLVM that the function pointer
was a constant value and could be aggressively inlined, so this updates the
`JsStatic` internals slightly to guarantee to LLVM that the function pointer is
constant and no dynamic dispatch is needed after all
Add support for `#[wasm_bindgen(readonly)]` which indicates that an exported
struct field is readonly and attempting to set it in JS will throw an exception.
Closes#151
Automatically infer public struct fields as "JS wants to access this" and
generate appropriate getters/setters for the field. At this time the field is
required to implement `Copy`, but we will probably want to relax that in the
future to at least encompass `JsValue` and maybe other `Clone` values as well.
Closes#121
This commit adds support for both `#![no_std]` in the wasm-bindgen runtime
support (disabled by default with an on-by-default `std` feature). This also
adds support to work and compile in the context of `#![no_std]` crates.
Closes#146
This commit overhauls the conversion traits used for types crossing the Rust/JS
boundary. Previously there were a few ad-hoc traits but now there've been
slightly reduced and decoupled.
Conversion from Rust values to JS values is now exclusively done through
`IntoWasmAbi` with no special treatment for references. Conversion from JS to
Rust is a bit trickier as we want to create references in Rust which have
implications in terms of safety. As a result there are now three traits for
this, `FromWasmAbi`, `RefFromWasmAbi`, and `RefMutFromWasmAbi`. These three
traits are implemented for various types and specially dispatched to depending
on the type of argument in the code generator.
The goal of this commit is to lay the groundwork for using these traits in
closures with straightforward-ish definitions.
This commit adds support for passing `&mut FnMut(..)` to JS via imports. These
closures cannot be invoked recursively in JS (they invalidate themselves while
they're being invoked) and otherwise work the same as `&Fn(..)` closures.
Closes#123
This commit is a complete overhaul of how the `#[wasm_bindgen]` macro
communicates type information to the CLI tool, and it's done in a somewhat...
unconventional fashion.
Today we've got a problem where the generated JS needs to understand the types
of each function exported or imported. This understanding is what enables it to
generate the appropriate JS wrappers and such. We want to, however, be quite
flexible and extensible in types that are supported across the boundary, which
means that internally we rely on the trait system to resolve what's what.
Communicating the type information historically was done by creating a four byte
"descriptor" and using associated type projections to communicate that to the
CLI tool. Unfortunately four bytes isn't a lot of space to cram information like
arguments to a generic function, tuple types, etc. In general this just wasn't
flexible enough and the way custom references were treated was also already a
bit of a hack.
This commit takes a radical step of creating a **descriptor function** for each
function imported/exported. The really crazy part is that the `wasm-bindgen` CLI
tool now embeds a wasm interpreter and executes these functions when the CLI
tool is invoked. By allowing arbitrary functions to get executed it's now *much*
easier to inform `wasm-bindgen` about complicated structures of types. Rest
assured though that all these descriptor functions are automatically unexported
and gc'd away, so this should not have any impact on binary sizes
A new internal trait, `WasmDescribe`, is added to represent a description of all
types, sort of like a serialization of the structure of a type that
`wasm-bindgen` can understand. This works by calling a special exported function
with a `u32` value a bunch of times. This means that when we run a descriptor we
effectively get a `Vec<u32>` in the `wasm-bindgen` CLI tool. This list of
integers can then be parsed into a rich `enum` for the JS generation to work
with.
This commit currently only retains feature parity with the previous
implementation. I hope to soon solve issues like #123, #104, and #111 with this
support.
This commit starts wasm-bindgen down the path of supporting closures. We
discussed this at the recent Rust All-Hands but I ended up needing to pretty
significantly scale back the ambitions of what closures are supported. This
commit is just the initial support and provides only a small amount of support
but will hopefully provide a good basis for future implementations.
Specifically this commit adds support for passing `&Fn(...)` to an *imported
function*, but nothing elese. The `&Fn` type can have any lifetime and the JS
object is invalidated as soon as the import returns. The arguments and return
value of `Fn` must currently implement the `WasmAbi` trait, aka they can't
require any conversions like strings/types/etc.
I'd like to soon expand this to `&mut FnMut` as well as `'static` closures that
can be passed around for a long time in JS, but for now I'm putting that off
until later. I'm not currently sure how to implement richer argument types, but
hopefully that can be figured out at some point!
