blob: 429a32896af8f12f082ee6f9d8d874511f3a038b [file] [log] [blame]
use core::char;
use core::mem::{self, ManuallyDrop};
use crate::convert::traits::WasmAbi;
use crate::convert::{FromWasmAbi, IntoWasmAbi, RefFromWasmAbi};
use crate::convert::{OptionFromWasmAbi, OptionIntoWasmAbi, ReturnWasmAbi};
use crate::{Clamped, JsError, JsValue};
unsafe impl WasmAbi for () {}
#[repr(C)]
pub struct WasmOptionalI32 {
pub present: u32,
pub value: i32,
}
unsafe impl WasmAbi for WasmOptionalI32 {}
#[repr(C)]
pub struct WasmOptionalU32 {
pub present: u32,
pub value: u32,
}
unsafe impl WasmAbi for WasmOptionalU32 {}
#[repr(C)]
pub struct WasmOptionalF32 {
pub present: u32,
pub value: f32,
}
unsafe impl WasmAbi for WasmOptionalF32 {}
#[repr(C)]
pub struct WasmOptionalF64 {
pub present: u32,
pub value: f64,
}
unsafe impl WasmAbi for WasmOptionalF64 {}
#[repr(C)]
pub struct Wasm64 {
pub low: u32,
pub high: u32,
}
unsafe impl WasmAbi for Wasm64 {}
#[repr(C)]
pub struct WasmOptional64 {
pub present: u32,
pub low: u32,
pub high: u32,
}
unsafe impl WasmAbi for WasmOptional64 {}
macro_rules! type_wasm_native {
($($t:tt as $c:tt => $r:tt)*) => ($(
impl IntoWasmAbi for $t {
type Abi = $c;
#[inline]
fn into_abi(self) -> $c { self as $c }
}
impl FromWasmAbi for $t {
type Abi = $c;
#[inline]
unsafe fn from_abi(js: $c) -> Self { js as $t }
}
impl IntoWasmAbi for Option<$t> {
type Abi = $r;
#[inline]
fn into_abi(self) -> $r {
match self {
None => $r {
present: 0,
value: 0 as $c,
},
Some(me) => $r {
present: 1,
value: me as $c,
},
}
}
}
impl FromWasmAbi for Option<$t> {
type Abi = $r;
#[inline]
unsafe fn from_abi(js: $r) -> Self {
if js.present == 0 {
None
} else {
Some(js.value as $t)
}
}
}
)*)
}
type_wasm_native!(
i32 as i32 => WasmOptionalI32
isize as i32 => WasmOptionalI32
u32 as u32 => WasmOptionalU32
usize as u32 => WasmOptionalU32
f32 as f32 => WasmOptionalF32
f64 as f64 => WasmOptionalF64
);
macro_rules! type_abi_as_u32 {
($($t:tt)*) => ($(
impl IntoWasmAbi for $t {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 { self as u32 }
}
impl FromWasmAbi for $t {
type Abi = u32;
#[inline]
unsafe fn from_abi(js: u32) -> Self { js as $t }
}
impl OptionIntoWasmAbi for $t {
#[inline]
fn none() -> u32 { 0x00FF_FFFFu32 }
}
impl OptionFromWasmAbi for $t {
#[inline]
fn is_none(js: &u32) -> bool { *js == 0x00FF_FFFFu32 }
}
)*)
}
type_abi_as_u32!(i8 u8 i16 u16);
macro_rules! type_64 {
($($t:tt)*) => ($(
impl IntoWasmAbi for $t {
type Abi = Wasm64;
#[inline]
fn into_abi(self) -> Wasm64 {
Wasm64 {
low: self as u32,
high: (self >> 32) as u32,
}
}
}
impl FromWasmAbi for $t {
type Abi = Wasm64;
#[inline]
unsafe fn from_abi(js: Wasm64) -> $t {
$t::from(js.low) | ($t::from(js.high) << 32)
}
}
impl IntoWasmAbi for Option<$t> {
type Abi = WasmOptional64;
#[inline]
fn into_abi(self) -> WasmOptional64 {
match self {
None => WasmOptional64 {
present: 0,
low: 0 as u32,
high: 0 as u32,
},
Some(me) => WasmOptional64 {
present: 1,
low: me as u32,
high: (me >> 32) as u32,
},
}
}
}
impl FromWasmAbi for Option<$t> {
type Abi = WasmOptional64;
#[inline]
unsafe fn from_abi(js: WasmOptional64) -> Self {
if js.present == 0 {
None
} else {
Some($t::from(js.low) | ($t::from(js.high) << 32))
}
}
}
)*)
}
type_64!(i64 u64);
impl IntoWasmAbi for bool {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 {
self as u32
}
}
impl FromWasmAbi for bool {
type Abi = u32;
#[inline]
unsafe fn from_abi(js: u32) -> bool {
js != 0
}
}
impl OptionIntoWasmAbi for bool {
#[inline]
fn none() -> u32 {
0x00FF_FFFFu32
}
}
impl OptionFromWasmAbi for bool {
#[inline]
fn is_none(js: &u32) -> bool {
*js == 0x00FF_FFFFu32
}
}
impl IntoWasmAbi for char {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 {
self as u32
}
}
impl FromWasmAbi for char {
type Abi = u32;
#[inline]
unsafe fn from_abi(js: u32) -> char {
char::from_u32_unchecked(js)
}
}
impl OptionIntoWasmAbi for char {
#[inline]
fn none() -> u32 {
0x00FF_FFFFu32
}
}
impl OptionFromWasmAbi for char {
#[inline]
fn is_none(js: &u32) -> bool {
*js == 0x00FF_FFFFu32
}
}
impl<T> IntoWasmAbi for *const T {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 {
self as u32
}
}
impl<T> FromWasmAbi for *const T {
type Abi = u32;
#[inline]
unsafe fn from_abi(js: u32) -> *const T {
js as *const T
}
}
impl<T> IntoWasmAbi for *mut T {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 {
self as u32
}
}
impl<T> FromWasmAbi for *mut T {
type Abi = u32;
#[inline]
unsafe fn from_abi(js: u32) -> *mut T {
js as *mut T
}
}
impl IntoWasmAbi for JsValue {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 {
let ret = self.idx;
mem::forget(self);
ret
}
}
impl FromWasmAbi for JsValue {
type Abi = u32;
#[inline]
unsafe fn from_abi(js: u32) -> JsValue {
JsValue::_new(js)
}
}
impl<'a> IntoWasmAbi for &'a JsValue {
type Abi = u32;
#[inline]
fn into_abi(self) -> u32 {
self.idx
}
}
impl RefFromWasmAbi for JsValue {
type Abi = u32;
type Anchor = ManuallyDrop<JsValue>;
#[inline]
unsafe fn ref_from_abi(js: u32) -> Self::Anchor {
ManuallyDrop::new(JsValue::_new(js))
}
}
impl<T: OptionIntoWasmAbi> IntoWasmAbi for Option<T> {
type Abi = T::Abi;
#[inline]
fn into_abi(self) -> T::Abi {
match self {
None => T::none(),
Some(me) => me.into_abi(),
}
}
}
impl<T: OptionFromWasmAbi> FromWasmAbi for Option<T> {
type Abi = T::Abi;
#[inline]
unsafe fn from_abi(js: T::Abi) -> Self {
if T::is_none(&js) {
None
} else {
Some(T::from_abi(js))
}
}
}
impl<T: IntoWasmAbi> IntoWasmAbi for Clamped<T> {
type Abi = T::Abi;
#[inline]
fn into_abi(self) -> Self::Abi {
self.0.into_abi()
}
}
impl<T: FromWasmAbi> FromWasmAbi for Clamped<T> {
type Abi = T::Abi;
#[inline]
unsafe fn from_abi(js: T::Abi) -> Self {
Clamped(T::from_abi(js))
}
}
impl IntoWasmAbi for () {
type Abi = ();
#[inline]
fn into_abi(self) {
self
}
}
/// This is an encoding of a Result. It can only store things that can be decoded by the JS
/// bindings.
///
/// At the moment, we do not write the exact struct packing layout of everything into the
/// glue/descriptions of datatypes, so T cannot be arbitrary. The current requirements of the
/// struct unpacker (StructUnpacker), which apply to ResultAbi<T> as a whole, are as follows:
///
/// - repr(C), of course
/// - u32/i32/f32/f64 fields at the "leaf fields" of the "field tree"
/// - layout equivalent to a completely flattened repr(C) struct, constructed by an in order
/// traversal of all the leaf fields in it.
///
/// This means that you can't embed struct A(u32, f64) as struct B(u32, A); because the "completely
/// flattened" struct AB(u32, u32, f64) would miss the 4 byte padding that is actually present
/// within B and then as a consequence also miss the 4 byte padding within A that repr(C) inserts.
///
/// The enemy is padding. Padding is only required when there is an `f64` field. So the enemy is
/// `f64` after anything else, particularly anything arbitrary. There is no smaller sized type, so
/// we don't need to worry about 1-byte integers, etc. It's best, therefore, to place your f64s
/// first in your structs, that's why we have `abi` first, although here it doesn't matter as the
/// other two fields total 8 bytes anyway.
///
#[repr(C)]
pub struct ResultAbi<T> {
/// This field is the same size/align as `T`.
abi: ResultAbiUnion<T>,
/// Order of args here is such that we can pop() the possible error first, deal with it and
/// move on. Later fields are popped off the stack first.
err: u32,
is_err: u32,
}
#[repr(C)]
pub union ResultAbiUnion<T> {
// ManuallyDrop is #[repr(transparent)]
ok: std::mem::ManuallyDrop<T>,
err: (),
}
unsafe impl<T: WasmAbi> WasmAbi for ResultAbi<T> {}
unsafe impl<T: WasmAbi> WasmAbi for ResultAbiUnion<T> {}
impl<T: IntoWasmAbi, E: Into<JsValue>> ReturnWasmAbi for Result<T, E> {
type Abi = ResultAbi<T::Abi>;
#[inline]
fn return_abi(self) -> Self::Abi {
match self {
Ok(v) => {
let abi = ResultAbiUnion {
ok: std::mem::ManuallyDrop::new(v.into_abi()),
};
ResultAbi {
abi,
is_err: 0,
err: 0,
}
}
Err(e) => {
let jsval = e.into();
ResultAbi {
abi: ResultAbiUnion { err: () },
is_err: 1,
err: jsval.into_abi(),
}
}
}
}
}
impl IntoWasmAbi for JsError {
type Abi = <JsValue as IntoWasmAbi>::Abi;
fn into_abi(self) -> Self::Abi {
self.value.into_abi()
}
}