wasmtime/runtime/gc/enabled/externref.rs
1//! Implementation of `externref` in Wasmtime.
2
3use super::{AnyRef, RootedGcRefImpl};
4use crate::prelude::*;
5use crate::runtime::vm::{self, VMGcRef, VMStore};
6use crate::{
7 AsContextMut, GcHeapOutOfMemory, GcRefImpl, GcRootIndex, HeapType, ManuallyRooted, RefType,
8 Result, Rooted, StoreContext, StoreContextMut, ValRaw, ValType, WasmTy,
9 store::{AutoAssertNoGc, StoreOpaque, StoreResourceLimiter},
10};
11use core::any::Any;
12use core::mem;
13use core::mem::MaybeUninit;
14
15/// An opaque, GC-managed reference to some host data that can be passed to
16/// WebAssembly.
17///
18/// The `ExternRef` type represents WebAssembly `externref` values. Wasm can't
19/// do anything with the `externref`s other than put them in tables, globals,
20/// and locals or pass them to other functions (such as imported functions from
21/// the host). Unlike `anyref`s, Wasm guests cannot directly allocate new
22/// `externref`s; only the host can.
23///
24/// You can use `ExternRef` to give access to host objects and control the
25/// operations that Wasm can perform on them via what functions you allow Wasm
26/// to import.
27///
28/// Like all WebAssembly references, these are opaque and unforgeable to Wasm:
29/// they cannot be faked and Wasm cannot, for example, cast the integer
30/// `0x12345678` into a reference, pretend it is a valid `externref`, and trick
31/// the host into dereferencing it and segfaulting or worse.
32///
33/// Note that you can also use `Rooted<ExternRef>` and
34/// `ManuallyRooted<ExternRef>` as a type parameter with
35/// [`Func::typed`][crate::Func::typed]- and
36/// [`Func::wrap`][crate::Func::wrap]-style APIs.
37///
38/// # Example
39///
40/// ```
41/// # use wasmtime::*;
42/// # use std::borrow::Cow;
43/// # fn _foo() -> Result<()> {
44/// let engine = Engine::default();
45/// let mut store = Store::new(&engine, ());
46///
47/// // Define some APIs for working with host strings from Wasm via `externref`.
48/// let mut linker = Linker::new(&engine);
49/// linker.func_wrap(
50/// "host-string",
51/// "new",
52/// |caller: Caller<'_, ()>| -> Result<Rooted<ExternRef>> {
53/// ExternRef::new(caller, Cow::from(""))
54/// },
55/// )?;
56/// linker.func_wrap(
57/// "host-string",
58/// "concat",
59/// |mut caller: Caller<'_, ()>, a: Rooted<ExternRef>, b: Rooted<ExternRef>| -> Result<Rooted<ExternRef>> {
60/// let mut s = a
61/// .data(&caller)?
62/// .ok_or_else(|| Error::msg("externref has no host data"))?
63/// .downcast_ref::<Cow<str>>()
64/// .ok_or_else(|| Error::msg("externref was not a string"))?
65/// .clone()
66/// .into_owned();
67/// let b = b
68/// .data(&caller)?
69/// .ok_or_else(|| Error::msg("externref has no host data"))?
70/// .downcast_ref::<Cow<str>>()
71/// .ok_or_else(|| Error::msg("externref was not a string"))?;
72/// s.push_str(&b);
73/// ExternRef::new(&mut caller, s)
74/// },
75/// )?;
76///
77/// // Here is a Wasm module that uses those APIs.
78/// let module = Module::new(
79/// &engine,
80/// r#"
81/// (module
82/// (import "host-string" "concat" (func $concat (param externref externref)
83/// (result externref)))
84/// (func (export "run") (param externref externref) (result externref)
85/// local.get 0
86/// local.get 1
87/// call $concat
88/// )
89/// )
90/// "#,
91/// )?;
92///
93/// // Create a couple `externref`s wrapping `Cow<str>`s.
94/// let hello = ExternRef::new(&mut store, Cow::from("Hello, "))?;
95/// let world = ExternRef::new(&mut store, Cow::from("World!"))?;
96///
97/// // Instantiate the module and pass the `externref`s into it.
98/// let instance = linker.instantiate(&mut store, &module)?;
99/// let result = instance
100/// .get_typed_func::<(Rooted<ExternRef>, Rooted<ExternRef>), Rooted<ExternRef>>(&mut store, "run")?
101/// .call(&mut store, (hello, world))?;
102///
103/// // The module should have concatenated the strings together!
104/// assert_eq!(
105/// result
106/// .data(&store)?
107/// .expect("externref should have host data")
108/// .downcast_ref::<Cow<str>>()
109/// .expect("host data should be a `Cow<str>`"),
110/// "Hello, World!"
111/// );
112/// # Ok(())
113/// # }
114/// ```
115#[derive(Debug, Clone)]
116#[repr(transparent)]
117pub struct ExternRef {
118 pub(crate) inner: GcRootIndex,
119}
120
121unsafe impl GcRefImpl for ExternRef {
122 fn transmute_ref(index: &GcRootIndex) -> &Self {
123 // Safety: `ExternRef` is a newtype of a `GcRootIndex`.
124 let me: &Self = unsafe { mem::transmute(index) };
125
126 // Assert we really are just a newtype of a `GcRootIndex`.
127 assert!(matches!(
128 me,
129 Self {
130 inner: GcRootIndex { .. },
131 }
132 ));
133
134 me
135 }
136}
137
138impl ExternRef {
139 /// Synchronously allocates a new `ExternRef` wrapping the given value.
140 ///
141 /// The resulting value is automatically unrooted when the given `context`'s
142 /// scope is exited. If you need to hold the reference past the `context`'s
143 /// scope, convert the result into a
144 /// [`ManuallyRooted<T>`][crate::ManuallyRooted]. See the documentation for
145 /// [`Rooted<T>`][crate::Rooted] and
146 /// [`ManuallyRooted<T>`][crate::ManuallyRooted] for more details.
147 ///
148 /// # Automatic Garbage Collection
149 ///
150 /// If the GC heap is at capacity, and there isn't room for allocating a new
151 /// `externref`, this method will automatically trigger a synchronous
152 /// collection in an attempt to free up space in the GC heap.
153 ///
154 /// # Errors
155 ///
156 /// If the allocation cannot be satisfied because the GC heap is currently
157 /// out of memory, then a [`GcHeapOutOfMemory<T>`][crate::GcHeapOutOfMemory]
158 /// error is returned. The allocation might succeed on a second attempt if
159 /// you drop some rooted GC references and try again.
160 ///
161 /// The [`GcHeapOutOfMemory<T>`][crate::GcHeapOutOfMemory] error contains
162 /// the host value that the `externref` would have wrapped. You can extract
163 /// that value from the error and reuse it when attempting to allocate an
164 /// `externref` again after dropping rooted GC references and then
165 /// performing a collection or otherwise do with it whatever you see fit.
166 ///
167 /// # Example
168 ///
169 /// ```
170 /// # use wasmtime::*;
171 /// # fn _foo() -> Result<()> {
172 /// let mut store = Store::<()>::default();
173 ///
174 /// {
175 /// let mut scope = RootScope::new(&mut store);
176 ///
177 /// // Allocate an `externref` wrapping a `String`.
178 /// let externref = match ExternRef::new(&mut scope, "hello!".to_string()) {
179 /// // The allocation succeeded.
180 /// Ok(x) => x,
181 /// // The allocation failed.
182 /// Err(e) => match e.downcast::<GcHeapOutOfMemory<String>>() {
183 /// // The allocation failed because the GC heap does not have
184 /// // capacity for this allocation.
185 /// Ok(oom) => {
186 /// // Take back ownership of our `String`.
187 /// let s = oom.into_inner();
188 /// // Drop some rooted GC refs from our system to potentially
189 /// // free up space for Wasmtime to make this allocation.
190 /// # let drop_some_gc_refs = || {};
191 /// drop_some_gc_refs();
192 /// // Finally, try to allocate again, reusing the original
193 /// // string.
194 /// ExternRef::new(&mut scope, s)?
195 /// }
196 /// Err(e) => return Err(e),
197 /// },
198 /// };
199 ///
200 /// // Use the `externref`, pass it to Wasm, etc...
201 /// }
202 ///
203 /// // The `externref` is automatically unrooted when we exit the scope.
204 /// # Ok(())
205 /// # }
206 /// ```
207 ///
208 /// # Panics
209 ///
210 /// Panics if the `context` is configured for async; use
211 /// [`ExternRef::new_async`][crate::ExternRef::new_async] to perform
212 /// asynchronous allocation instead.
213 pub fn new<T>(mut store: impl AsContextMut, value: T) -> Result<Rooted<ExternRef>>
214 where
215 T: 'static + Any + Send + Sync,
216 {
217 let (mut limiter, store) = store.as_context_mut().0.resource_limiter_and_store_opaque();
218 assert!(!store.async_support());
219 vm::assert_ready(Self::_new_async(store, limiter.as_mut(), value))
220 }
221
222 /// Asynchronously allocates a new `ExternRef` wrapping the given value.
223 ///
224 /// The resulting value is automatically unrooted when the given `context`'s
225 /// scope is exited. If you need to hold the reference past the `context`'s
226 /// scope, convert the result into a
227 /// [`ManuallyRooted<T>`][crate::ManuallyRooted]. See the documentation for
228 /// [`Rooted<T>`][crate::Rooted] and
229 /// [`ManuallyRooted<T>`][crate::ManuallyRooted] for more details.
230 ///
231 /// # Automatic Garbage Collection
232 ///
233 /// If the GC heap is at capacity, and there isn't room for allocating a new
234 /// `externref`, this method will automatically trigger an asynchronous
235 /// collection in an attempt to free up space in the GC heap.
236 ///
237 /// # Errors
238 ///
239 /// If the allocation cannot be satisfied because the GC heap is currently
240 /// out of memory, then a [`GcHeapOutOfMemory<T>`][crate::GcHeapOutOfMemory]
241 /// error is returned. The allocation might succeed on a second attempt if
242 /// you drop some rooted GC references and try again.
243 ///
244 /// The [`GcHeapOutOfMemory<T>`][crate::GcHeapOutOfMemory] error contains
245 /// the host value that the `externref` would have wrapped. You can extract
246 /// that value from the error and reuse it when attempting to allocate an
247 /// `externref` again after dropping rooted GC references and then
248 /// performing a collection or otherwise do with it whatever you see fit.
249 ///
250 /// # Example
251 ///
252 /// ```
253 /// use wasmtime::*;
254 ///
255 /// # async fn _foo() -> Result<()> {
256 /// let mut store = Store::<()>::default();
257 ///
258 /// {
259 /// let mut scope = RootScope::new(&mut store);
260 ///
261 /// // Create an `externref` wrapping a `String`.
262 /// let externref = match ExternRef::new_async(&mut scope, "hello!".to_string()).await {
263 /// // The allocation succeeded.
264 /// Ok(x) => x,
265 /// // The allocation failed.
266 /// Err(e) => match e.downcast::<GcHeapOutOfMemory<String>>() {
267 /// // The allocation failed because the GC heap does not have
268 /// // capacity for this allocation.
269 /// Ok(oom) => {
270 /// // Take back ownership of our `String`.
271 /// let s = oom.into_inner();
272 /// // Drop some rooted GC refs from our system to potentially
273 /// // free up space for Wasmtime to make this allocation.
274 /// # let drop_some_gc_refs = || {};
275 /// drop_some_gc_refs();
276 /// // Finally, try to allocate again, reusing the original
277 /// // string.
278 /// ExternRef::new_async(&mut scope, s).await?
279 /// }
280 /// Err(e) => return Err(e),
281 /// },
282 /// };
283 ///
284 /// // Use the `externref`, pass it to Wasm, etc...
285 /// }
286 ///
287 /// // The `externref` is automatically unrooted when we exit the scope.
288 /// # Ok(())
289 /// # }
290 /// ```
291 ///
292 /// # Panics
293 ///
294 /// Panics if the `context` is not configured for async; use
295 /// [`ExternRef::new`][crate::ExternRef::new] to perform synchronous
296 /// allocation instead.
297 #[cfg(feature = "async")]
298 pub async fn new_async<T>(mut store: impl AsContextMut, value: T) -> Result<Rooted<ExternRef>>
299 where
300 T: 'static + Any + Send + Sync,
301 {
302 let (mut limiter, store) = store.as_context_mut().0.resource_limiter_and_store_opaque();
303 Self::_new_async(store, limiter.as_mut(), value).await
304 }
305
306 pub(crate) async fn _new_async<T>(
307 store: &mut StoreOpaque,
308 limiter: Option<&mut StoreResourceLimiter<'_>>,
309 value: T,
310 ) -> Result<Rooted<ExternRef>>
311 where
312 T: 'static + Any + Send + Sync,
313 {
314 // Allocate the box once, regardless how many gc-and-retry attempts we
315 // make.
316 let value: Box<dyn Any + Send + Sync> = Box::new(value);
317
318 let gc_ref = store
319 .retry_after_gc_async(limiter, value, |store, value| {
320 store
321 .require_gc_store_mut()?
322 .alloc_externref(value)
323 .context("unrecoverable error when allocating new `externref`")?
324 .map_err(|(x, n)| GcHeapOutOfMemory::new(x, n).into())
325 })
326 .await
327 // Translate the `GcHeapOutOfMemory`'s inner value from the boxed
328 // trait object into `T`.
329 .map_err(
330 |e| match e.downcast::<GcHeapOutOfMemory<Box<dyn Any + Send + Sync>>>() {
331 Ok(oom) => oom.map_inner(|x| *x.downcast::<T>().unwrap()).into(),
332 Err(e) => e,
333 },
334 )?;
335
336 let mut ctx = AutoAssertNoGc::new(store);
337 Ok(Self::from_cloned_gc_ref(&mut ctx, gc_ref.into()))
338 }
339
340 /// Convert an `anyref` into an `externref`.
341 ///
342 /// This is equivalent to the `extern.convert_any` instruction in Wasm.
343 ///
344 /// You can get the underlying `anyref` again via the
345 /// [`AnyRef::convert_extern`] method or the `any.convert_extern` Wasm
346 /// instruction.
347 ///
348 /// The resulting `ExternRef` will not have any host data associated with
349 /// it, so [`ExternRef::data`] and [`ExternRef::data_mut`] will both return
350 /// `None`.
351 ///
352 /// Returns an error if the `anyref` GC reference has been unrooted (eg if
353 /// you attempt to use a `Rooted<AnyRef>` after exiting the scope it was
354 /// rooted within). See the documentation for [`Rooted<T>`][crate::Rooted]
355 /// for more details.
356 ///
357 /// # Example
358 ///
359 /// ```
360 /// use wasmtime::*;
361 /// # fn foo() -> Result<()> {
362 /// let engine = Engine::default();
363 /// let mut store = Store::new(&engine, ());
364 ///
365 /// // Create an `anyref`.
366 /// let i31 = I31::wrapping_u32(0x1234);
367 /// let anyref = AnyRef::from_i31(&mut store, i31);
368 ///
369 /// // Convert that `anyref` into an `externref`.
370 /// let externref = ExternRef::convert_any(&mut store, anyref)?;
371 ///
372 /// // This `externref` doesn't have any associated host data.
373 /// assert!(externref.data(&store)?.is_none());
374 ///
375 /// // We can convert it back to an `anyref` and get its underlying `i31`
376 /// // data.
377 /// let anyref = AnyRef::convert_extern(&mut store, externref)?;
378 /// assert_eq!(anyref.unwrap_i31(&store)?.get_u32(), 0x1234);
379 /// # Ok(()) }
380 /// # foo().unwrap();
381 pub fn convert_any(
382 mut context: impl AsContextMut,
383 anyref: Rooted<AnyRef>,
384 ) -> Result<Rooted<ExternRef>> {
385 let mut store = AutoAssertNoGc::new(context.as_context_mut().0);
386 Self::_convert_any(&mut store, anyref)
387 }
388
389 pub(crate) fn _convert_any(
390 store: &mut AutoAssertNoGc<'_>,
391 anyref: Rooted<AnyRef>,
392 ) -> Result<Rooted<ExternRef>> {
393 let gc_ref = anyref.try_clone_gc_ref(store)?;
394 Ok(Self::from_cloned_gc_ref(store, gc_ref))
395 }
396
397 /// Create a new `Rooted<ExternRef>` from the given GC reference.
398 ///
399 /// Does not invoke the `GcRuntime`'s clone hook; callers should ensure it
400 /// has been called.
401 ///
402 /// `gc_ref` should be a GC reference pointing to an instance of `externref`
403 /// that is in this store's GC heap. Failure to uphold this invariant is
404 /// memory safe but will result in general incorrectness such as panics and
405 /// wrong results.
406 pub(crate) fn from_cloned_gc_ref(
407 store: &mut AutoAssertNoGc<'_>,
408 gc_ref: VMGcRef,
409 ) -> Rooted<Self> {
410 if !gc_ref.is_i31() {
411 assert!(
412 gc_ref.is_extern_ref(&*store.unwrap_gc_store().gc_heap)
413 || gc_ref.is_any_ref(&*store.unwrap_gc_store().gc_heap),
414 "GC reference {gc_ref:#p} should be an externref or anyref"
415 );
416 }
417 Rooted::new(store, gc_ref)
418 }
419
420 /// Get a shared borrow of the underlying data for this `ExternRef`.
421 ///
422 /// Returns `None` if this is an `externref` wrapper of an `anyref` created
423 /// by the `extern.convert_any` instruction or the
424 /// [`ExternRef::convert_any`] method.
425 ///
426 /// Returns an error if this `externref` GC reference has been unrooted (eg
427 /// if you attempt to use a `Rooted<ExternRef>` after exiting the scope it
428 /// was rooted within). See the documentation for
429 /// [`Rooted<T>`][crate::Rooted] for more details.
430 ///
431 /// # Example
432 ///
433 /// ```
434 /// # use wasmtime::*;
435 /// # fn _foo() -> Result<()> {
436 /// let mut store = Store::<()>::default();
437 ///
438 /// let externref = ExternRef::new(&mut store, "hello")?;
439 ///
440 /// // Access the `externref`'s host data.
441 /// let data = externref.data(&store)?.ok_or_else(|| Error::msg("no host data"))?;
442 /// // Dowcast it to a `&str`.
443 /// let data = data.downcast_ref::<&str>().ok_or_else(|| Error::msg("not a str"))?;
444 /// // We should have got the data we created the `externref` with!
445 /// assert_eq!(*data, "hello");
446 /// # Ok(())
447 /// # }
448 /// ```
449 pub fn data<'a, T>(
450 &self,
451 store: impl Into<StoreContext<'a, T>>,
452 ) -> Result<Option<&'a (dyn Any + Send + Sync)>>
453 where
454 T: 'static,
455 {
456 let store = store.into().0;
457 let gc_ref = self.inner.try_gc_ref(&store)?;
458 if gc_ref.is_i31() {
459 return Ok(None);
460 }
461 let gc_store = store.require_gc_store()?;
462 if let Some(externref) = gc_ref.as_externref(&*gc_store.gc_heap) {
463 Ok(Some(gc_store.externref_host_data(externref)))
464 } else {
465 Ok(None)
466 }
467 }
468
469 /// Get an exclusive borrow of the underlying data for this `ExternRef`.
470 ///
471 /// Returns `None` if this is an `externref` wrapper of an `anyref` created
472 /// by the `extern.convert_any` instruction or the
473 /// [`ExternRef::convert_any`] constructor.
474 ///
475 /// Returns an error if this `externref` GC reference has been unrooted (eg
476 /// if you attempt to use a `Rooted<ExternRef>` after exiting the scope it
477 /// was rooted within). See the documentation for
478 /// [`Rooted<T>`][crate::Rooted] for more details.
479 ///
480 /// # Example
481 ///
482 /// ```
483 /// # use wasmtime::*;
484 /// # fn _foo() -> Result<()> {
485 /// let mut store = Store::<()>::default();
486 ///
487 /// let externref = ExternRef::new::<usize>(&mut store, 0)?;
488 ///
489 /// // Access the `externref`'s host data.
490 /// let data = externref.data_mut(&mut store)?.ok_or_else(|| Error::msg("no host data"))?;
491 /// // Dowcast it to a `usize`.
492 /// let data = data.downcast_mut::<usize>().ok_or_else(|| Error::msg("not a usize"))?;
493 /// // We initialized to zero.
494 /// assert_eq!(*data, 0);
495 /// // And we can mutate the value!
496 /// *data += 10;
497 /// # Ok(())
498 /// # }
499 /// ```
500 pub fn data_mut<'a, T>(
501 &self,
502 store: impl Into<StoreContextMut<'a, T>>,
503 ) -> Result<Option<&'a mut (dyn Any + Send + Sync)>>
504 where
505 T: 'static,
506 {
507 let store = store.into().0;
508 // NB: need to do an unchecked copy to release the borrow on the store
509 // so that we can get the store's GC store. But importantly we cannot
510 // trigger a GC while we are working with `gc_ref` here.
511 let gc_ref = self.inner.try_gc_ref(store)?.unchecked_copy();
512 if gc_ref.is_i31() {
513 return Ok(None);
514 }
515 let gc_store = store.require_gc_store_mut()?;
516 if let Some(externref) = gc_ref.as_externref(&*gc_store.gc_heap) {
517 Ok(Some(gc_store.externref_host_data_mut(externref)))
518 } else {
519 Ok(None)
520 }
521 }
522
523 /// Creates a new strongly-owned [`ExternRef`] from the raw value provided.
524 ///
525 /// This is intended to be used in conjunction with [`Func::new_unchecked`],
526 /// [`Func::call_unchecked`], and [`ValRaw`] with its `externref` field.
527 ///
528 /// This function assumes that `raw` is an externref value which is
529 /// currently rooted within the [`Store`].
530 ///
531 /// # Correctness
532 ///
533 /// This function is tricky to get right because `raw` not only must be a
534 /// valid `externref` value produced prior by [`ExternRef::to_raw`] but it
535 /// must also be correctly rooted within the store. When arguments are
536 /// provided to a callback with [`Func::new_unchecked`], for example, or
537 /// returned via [`Func::call_unchecked`], if a GC is performed within the
538 /// store then floating `externref` values are not rooted and will be GC'd,
539 /// meaning that this function will no longer be correct to call with the
540 /// values cleaned up. This function must be invoked *before* possible GC
541 /// operations can happen (such as calling Wasm).
542 ///
543 ///
544 /// When in doubt try to not use this. Instead use the Rust APIs of
545 /// [`TypedFunc`] and friends. Note though that this function is not
546 /// `unsafe` as any value can be passed in. Incorrect values can result in
547 /// runtime panics, however, so care must still be taken with this method.
548 ///
549 /// [`Func::call_unchecked`]: crate::Func::call_unchecked
550 /// [`Func::new_unchecked`]: crate::Func::new_unchecked
551 /// [`Store`]: crate::Store
552 /// [`TypedFunc`]: crate::TypedFunc
553 /// [`ValRaw`]: crate::ValRaw
554 pub fn from_raw(mut store: impl AsContextMut, raw: u32) -> Option<Rooted<ExternRef>> {
555 let mut store = AutoAssertNoGc::new(store.as_context_mut().0);
556 Self::_from_raw(&mut store, raw)
557 }
558
559 // (Not actually memory unsafe since we have indexed GC heaps.)
560 pub(crate) fn _from_raw(store: &mut AutoAssertNoGc, raw: u32) -> Option<Rooted<ExternRef>> {
561 let gc_ref = VMGcRef::from_raw_u32(raw)?;
562 let gc_ref = store.clone_gc_ref(&gc_ref);
563 Some(Self::from_cloned_gc_ref(store, gc_ref))
564 }
565
566 /// Converts this [`ExternRef`] to a raw value suitable to store within a
567 /// [`ValRaw`].
568 ///
569 /// Returns an error if this `externref` has been unrooted.
570 ///
571 /// # Correctness
572 ///
573 /// Produces a raw value which is only valid to pass into a store if a GC
574 /// doesn't happen between when the value is produce and when it's passed
575 /// into the store.
576 ///
577 /// [`ValRaw`]: crate::ValRaw
578 pub fn to_raw(&self, mut store: impl AsContextMut) -> Result<u32> {
579 let mut store = AutoAssertNoGc::new(store.as_context_mut().0);
580 self._to_raw(&mut store)
581 }
582
583 pub(crate) fn _to_raw(&self, store: &mut AutoAssertNoGc) -> Result<u32> {
584 let gc_ref = self.inner.try_clone_gc_ref(store)?;
585 let raw = store.unwrap_gc_store_mut().expose_gc_ref_to_wasm(gc_ref);
586 Ok(raw.get())
587 }
588}
589
590unsafe impl WasmTy for Rooted<ExternRef> {
591 #[inline]
592 fn valtype() -> ValType {
593 ValType::Ref(RefType::new(false, HeapType::Extern))
594 }
595
596 #[inline]
597 fn compatible_with_store(&self, store: &StoreOpaque) -> bool {
598 self.comes_from_same_store(store)
599 }
600
601 #[inline]
602 fn dynamic_concrete_type_check(&self, _: &StoreOpaque, _: bool, _: &HeapType) -> Result<()> {
603 unreachable!()
604 }
605
606 fn store(self, store: &mut AutoAssertNoGc<'_>, ptr: &mut MaybeUninit<ValRaw>) -> Result<()> {
607 self.wasm_ty_store(store, ptr, ValRaw::externref)
608 }
609
610 unsafe fn load(store: &mut AutoAssertNoGc<'_>, ptr: &ValRaw) -> Self {
611 Self::wasm_ty_load(store, ptr.get_externref(), ExternRef::from_cloned_gc_ref)
612 }
613}
614
615unsafe impl WasmTy for Option<Rooted<ExternRef>> {
616 #[inline]
617 fn valtype() -> ValType {
618 ValType::EXTERNREF
619 }
620
621 #[inline]
622 fn compatible_with_store(&self, store: &StoreOpaque) -> bool {
623 self.map_or(true, |x| x.comes_from_same_store(store))
624 }
625
626 #[inline]
627 fn dynamic_concrete_type_check(&self, _: &StoreOpaque, _: bool, _: &HeapType) -> Result<()> {
628 unreachable!()
629 }
630
631 #[inline]
632 fn is_vmgcref_and_points_to_object(&self) -> bool {
633 self.is_some()
634 }
635
636 fn store(self, store: &mut AutoAssertNoGc<'_>, ptr: &mut MaybeUninit<ValRaw>) -> Result<()> {
637 <Rooted<ExternRef>>::wasm_ty_option_store(self, store, ptr, ValRaw::externref)
638 }
639
640 unsafe fn load(store: &mut AutoAssertNoGc<'_>, ptr: &ValRaw) -> Self {
641 <Rooted<ExternRef>>::wasm_ty_option_load(
642 store,
643 ptr.get_externref(),
644 ExternRef::from_cloned_gc_ref,
645 )
646 }
647}
648
649unsafe impl WasmTy for ManuallyRooted<ExternRef> {
650 #[inline]
651 fn valtype() -> ValType {
652 ValType::Ref(RefType::new(false, HeapType::Extern))
653 }
654
655 #[inline]
656 fn compatible_with_store(&self, store: &StoreOpaque) -> bool {
657 self.comes_from_same_store(store)
658 }
659
660 #[inline]
661 fn dynamic_concrete_type_check(&self, _: &StoreOpaque, _: bool, _: &HeapType) -> Result<()> {
662 unreachable!()
663 }
664
665 #[inline]
666 fn is_vmgcref_and_points_to_object(&self) -> bool {
667 true
668 }
669
670 fn store(self, store: &mut AutoAssertNoGc<'_>, ptr: &mut MaybeUninit<ValRaw>) -> Result<()> {
671 self.wasm_ty_store(store, ptr, ValRaw::externref)
672 }
673
674 unsafe fn load(store: &mut AutoAssertNoGc<'_>, ptr: &ValRaw) -> Self {
675 Self::wasm_ty_load(store, ptr.get_externref(), ExternRef::from_cloned_gc_ref)
676 }
677}
678
679unsafe impl WasmTy for Option<ManuallyRooted<ExternRef>> {
680 #[inline]
681 fn valtype() -> ValType {
682 ValType::EXTERNREF
683 }
684
685 #[inline]
686 fn compatible_with_store(&self, store: &StoreOpaque) -> bool {
687 self.as_ref()
688 .map_or(true, |x| x.comes_from_same_store(store))
689 }
690
691 #[inline]
692 fn dynamic_concrete_type_check(&self, _: &StoreOpaque, _: bool, _: &HeapType) -> Result<()> {
693 unreachable!()
694 }
695
696 #[inline]
697 fn is_vmgcref_and_points_to_object(&self) -> bool {
698 self.is_some()
699 }
700
701 fn store(self, store: &mut AutoAssertNoGc<'_>, ptr: &mut MaybeUninit<ValRaw>) -> Result<()> {
702 <ManuallyRooted<ExternRef>>::wasm_ty_option_store(self, store, ptr, ValRaw::externref)
703 }
704
705 unsafe fn load(store: &mut AutoAssertNoGc<'_>, ptr: &ValRaw) -> Self {
706 <ManuallyRooted<ExternRef>>::wasm_ty_option_load(
707 store,
708 ptr.get_externref(),
709 ExternRef::from_cloned_gc_ref,
710 )
711 }
712}