Changes in multi-return.rs

96e19700 - Migrate the `wasmtime` crate to `wasmtime_environ::error::*` (#12231)

Wed, 07 Jan 2026 17:08:11 +0000

Migrate the `wasmtime` crate to `wasmtime_environ::error::*` (#12231)* Migrate the `wasmtime` crate to `wasmtime_environ::error::*`Instead of `anyhow::Error`.This commit re-exports the `wasmtime_environ::error` as the `wasmtime::error`module, updates the prelude to include these new error-handling types, redirectsour top-level `wasmtime::{Error, Result}` re-exports to re-export`wasmtime::error::{Error, Result}`, and updates various use sites that weredirectly using `anyhow` to use the new `wasmtime` versions.This process also required updating the component macro and wit-bindgen macro touse the new error types instead of `anyhow`.Part of https://github.com/bytecodealliance/wasmtime/issues/12069* Replace wasmtime::error::Thing with wasmtime::Thing where it makes sense* cargo fmt* Move `crate::error::Thing` to `crate::Thing` where it makes sense List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

b221fca7 - update `component-model-async` plumbing (#11123)

Thu, 03 Jul 2025 22:03:59 +0000

update `component-model-async` plumbing (#11123)* [DO NOT MERGE] update `component-model-async` plumbingThis pulls in the latest Component Model async ABI code from the`wasip3-prototyping` repo, including various API refactors and spec updates.This includes all the changes to the `wasmtime` crate from `wasip3-prototyping`_except_ that the `concurrent` submodule and child submodules contain onlynon-functional stubs. For that reason, and the fact thate.g. `Func::call_async` is now implemented in terms of `Func::call_concurrent`,most of the component model tests are failing. This commit is not meant to bemerged as-is; a follow-up commit (to be PR'd separately) will contain the real`concurrent` implementation, at which point the tests will pass again. I'msplitting these into separate PRs to make review easier.Signed-off-by: Joel Dice * Undo wit-bindgen changesNo longer necessary after other refactors* Move back to crates.io-based wit-bindgen* Undo upgrade of http-body-util(deferred for future PR)* Add back in arbitrary use of asyncLooks like it may have been lost by accident* Make imports more conventional for Wasmtime* Some minor changes* Privatize a component field* Cut down a bit on #[cfg]* Undo a no-longer-necessary `pub`* add doc comments for `{Future,Stream,ErrorContext}Any`Signed-off-by: Joel Dice * rename `concurrent` stub module to `concurrent_disabled`...and avoid panicking in the stubs.Signed-off-by: Joel Dice * fix test regressionSigned-off-by: Joel Dice * revert `call_async` and `post_return_impl` changesThese will need to wait until the `component-model-async` feature is fullyimplemented.Signed-off-by: Joel Dice * remove unused structSigned-off-by: Joel Dice * add `Options::callback` fieldThis isn't used yet, but will be used when the real `component-model-async`implementation is merged.Signed-off-by: Joel Dice * Remove no-longer-needed feature* Trim reexports from WasmtimeSome of these are no longer needed or can be avoided with small changes.Some deps are likely needed in the next commit but they'll be best addedthere.* Update test expectations* More trimming of Cargo.toml* Defer `*Buffer` traits to next PRNot needed for this PR I believe.* Use conventional Wasmtime imports + remove dummy_waker* Reduce duplication in `*_disabled`* Remove some unncessary bounds* Remove some `for<'a>` bounds where unnecessary* Remove another bound* Defer more functions to the next PR`drop_fibers` is different in the next PR, so defer it to then.* Remove some reexports no longer necessaryBindings generation changed awhile back so these aren't needed, deferthe implementations to the next PR.* Remove unnecessary dropThis was already moved to `run_manual_drop_routines`* Defer a `pub(crate)` to a future PR* Expand comments in traphandlers* Defer some types to the next PR* Update linker documentation* Add `Send`/`Sync` bounds to `ComponentType`This commit is extracted from from review of #11123 and #11127. Whilenot literally present in those PRs it's my own personal conclusion thatit's best to just go ahead and add these bounds at the "base" of thecomponent trait hierarchy. The current implementation in #11123 addsbounds in many locations and this would remove the need to add boundseverywhere and instead have everything inherited through the `Lift` and`Lower` traits.This raises the question of: why? The main conclusion that I've reachedleading to this change is that Wasmtime currently will store `R`, areturn value, on the stack during the lowering process back into linearmemory. This might involve allocation, however, meaning that wasm can beinvoked and a context switch could happen. For Wasmtime's `unsafe impl`of `Send` and `Sync` on fibers to be sound it requires that thisstack-local variable is also `Send` and `Sync` as it's an entirelyuser-provided type. Thus I've concluded that for results it's alwaysrequired for these to be both `Send` and `Sync` (or at the very least,`Send`).Given that I've gone ahead and updated to require both `Send` and `Sync`for both params and results. This is not expected to actually have anyimpact in practice since all primitives are already `Send`/`Sync` (minus`Rc` impls all removed here) and all `bindgen!`-generated types arecompositions of `Send`/`Sync` primitives meaning that they're also`Send` and `Sync`.* Remove some now-unnecessary bounds* Fix build after #11160* Remove some now-unnecessary duplicate bounds* Uncomment test that now works* Undo accidental doc wrap* Clarify comment on `Value` typesDon't leave `TODO` in public-facing documentation ideally* Actually resolve the conflict (forgot to commit)* Avoid returning boxed futures in APIs* Defer making constructors more public to a future PR* Make a method name more conventional* Refactor `linear_lift_into_from_memory`* Drop the `max_count` parameter in favor of slicing the `WasmList` itself. Avoids situations such as what happens if `max_count` is larger than the length of the list.* Don't have the default implementation collect to a vector and then push all that onto a different vector. Instead push each item individually through `extend`.* De-indent a block of code added* Remove unsafety from `prepare_call`Mostly move the parameters themselves to the closure to avoid rawpointers/drop/etc.This will have the consequence of in the future `call_async` is going tonow require `Params: 'static` but that seems more-or-less inevitable atthis point.* Go back to returning box, alas.* Apply same treatment to lift functionMake it a closure and reduce some levels of indirection of the variousfunctions in play.* Refactor `lower_params` to require less context.Relax the bounds on the closure specified since it's immediately calledand then additionally take out parameters/captures that the closure cancarry itself.* Don't pass extraneous `Instance` parameterThis can now be inferred from `Func`.* Clean up some SAFETY comments* Generalize the signature of `lift_results`* Move `lift_results` function to `Func`Also rename the lift/lower helpers to `with_{lift,lower}_context`* Remove parameter from `with_lift_context`Like `with_lower_context` this is fine to capture in the closure passedin.* Simplify the dynamic lifting logicDon't call `with_lift_context` in two locations, only call it once witha dynamic parameter.* Refactor away the `Func::lift_results_sync` helper* Use `with_lift_context` in `call_raw`* Simplify a call to `Func::call_unchecked_raw`* Ungate `with_lift_context` to fix non-cm-async build* Fix compile (bad cherry-pick conflict resolution)* Use `with_lower_context` in `call_raw`Trying to unify the async/concurrent paths as much as possible.* Move params out of `call_raw`Let closures capture the params, no need to thread it through as anunnecessary argument.* Clean up unsafety in `Func::call_raw`* Accurately mark `call_raw` itself as `unsafe`, then document why callers should be safe.* Don't have one large `unsafe` block in `call_raw`, instead split it up with separate safety comments.* Move a one-off type definition closer to its use* Avoid intermediate allocations in dynamic calls* Simplify a future-return site* Deduplicate checking parameter count* Simplify a future invocation with `?`* Simplify a variable declaration* Simplify some function signatures* Remove outdated safety comment* Refactor to not require `Params: 'static` on `call_async`* Remove no-longer-necessary SAFETY comment* Fix typos* Add a fast-path with no `Box` for sync host functionsSpeeds up host calls by ~20% and puts them back on parity with thebeforehand numbers Wasmtime has.* Synchronize signatures of async/concurrent dynamic callsUse slices for both instead of vecs for one and slices for the other.Required some slight rejiggering. Apparently one can solve a closureproblem with another closure, then one surely has no more closureproblems.* Fix non-cm-async build---------Signed-off-by: Joel Dice Co-authored-by: Alex Crichton List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

636435f1 - async/stream/future support for wasmtime-wit-bindgen (#10044)

Wed, 22 Jan 2025 17:19:46 +0000

async/stream/future support for wasmtime-wit-bindgen (#10044)* async/stream/future support for wasmtime-wit-bindgenI've split this out of #9582 to make review easier.This patch adds async/stream/future/error-context support to the host bindinggenerator, along with placeholder type and function definitions in the`wasmtime` crate which the generated bindings can refer to. Seehttps://github.com/dicej/rfcs/blob/component-async/accepted/component-model-async.md#componentbindgen-updatesfor the design and rationale.Note that I've added temporary `[patch.crates-io]` overrides in Cargo.toml untilhttps://github.com/bytecodealliance/wit-bindgen/pull/1130 andhttps://github.com/bytecodealliance/wasm-tools/pull/1978 have been released.Also note that we emit a `T: 'static` bound for `AsContextMut` whengenerating bindings with `concurrent_imports: true`. This is only because`rustc` insists that the closure we're passing to`LinkerInstance::func_wrap_concurrent` captures the lifetime of `T` despite mybest efforts to convince it otherwise. Alex and I suspect this is a limitationin the compiler, and I asked about it on the rust-lang Zulip, but we haven'tbeen able to determine a workaround so far.Signed-off-by: Joel Dice remove obsolete TODO commentSigned-off-by: Joel Dice make `futures` dep optionalSigned-off-by: Joel Dice update `wasm-tools` and `wit-bindgen`Signed-off-by: Joel Dice * run cargo vetSigned-off-by: Joel Dice ---------Signed-off-by: Joel Dice List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

afd8bb39 - Add async example to bindgen_examples (#9822)

Fri, 20 Dec 2024 19:34:10 +0000

Add async example to bindgen_examples (#9822)* add async example* fix bindgen bug to make CI happySee https://github.com/bytecodealliance/wasmtime/pull/9822#issuecomment-2546851949* update test expectations* remove async_trait List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

99d861cb - Expand the set of constructors of `bindgen!`-generated bindings (#9177)

Wed, 28 Aug 2024 16:36:26 +0000

Expand the set of constructors of `bindgen!`-generated bindings (#9177)* Expand the set of constructors of `bindgen!`-generated bindingsThis commit expands the set of supported constructors for `bindgen!`generated structures with the goal of bringing back`World::new(&mut store, instance)`. This method was removed previouslyin a refactoring to add `*Pre` structures but refactoring preexistingcode to use `*Pre` isn't always easy, so these extra generated bindingsprovide a smoother migration path for code from before.* Update test expectations List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

5393c2bf - Reduce typo count (#8951)

Mon, 15 Jul 2024 14:26:59 +0000

Reduce typo count (#8951) List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

f471b4dc - Refactor and document the wasmtime-wasi-http more (#8861)

Mon, 24 Jun 2024 15:24:58 +0000

Refactor and document the wasmtime-wasi-http more (#8861)* Improve some documentation of the `wasmtime-wasi` crateShow a few examples of using `with` to point to upstream `wasmtime-wasi`for bindings.* Refactor and document the `wasmtime-wasi-http` moreThis commit primarily adds a complete example of using`wasmtime-wasi-http` to the documentation. Along the way I've done anumber of other refactorings too:* `bindgen!`-generated `*Pre` structures now implement `Clone`.* `bindgen!`-generated `*Pre` structures now have an `engine` method.* `bindgen!`-generated `*Pre` structures now have an `instance_pre` method.* The structure of `wasmtime-wasi-http` now matches `wasmtime-wasi`, notably: * The `proxy` module is removed * `wasmtime_wasi_http::add_to_linker_{a,}sync` is the top level add-to-linker function. * The `bindings` module now contains `Proxy` and `ProxyPre` along with a `sync` submodule. * The `bindings` module contains all bindings for `wasi:http` things.* The `add_only_*` methods are un-hidden and documented.* Code processing `req` has been simplified by avoiding decomposing-and-reconstructing a request.* The `new_incoming_request` method is now generic to avoid callers having to do boxing/mapping themselves.* Update expanded macro expectations* Remove unused import List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

3171ef6d - Redesign how component exports work (#8786)

Tue, 18 Jun 2024 01:05:39 +0000

Redesign how component exports work (#8786)* Un-nest exports in a componentThis commit flattens the representation of exports in a component tomake them more easily indexable without forcing traversal through thehierarchy of instance imports/exports to get there.* Guarantee type information on component exportsDon't have it optional in some cases and present in others, insteadensure there's type information for all component exports immediatelyavailable.* Refactor how component instance exports are loadedThis commit is a change to Wasmtime's public API for`wasmtime::component::Instance` that reorganizes how component exportsare loaded. Previously there was a system where `Instance::exports()`was called that that was sort of "iterated over" in a builder-stylepattern to acquire the actual export desired. This required lifetimetrickery for nested instances and some unfortunate API bloat. The majordownside of this approach is that it requires unconditional stringlookups at runtime for exports and additionally does not serve as agreat place to implement the semver-compatible logic of #8395. The goalof this refactoring is to pave the way to improving this.The new APIs for loading exports now look a bit more similar to what'savailable for core modules. Notably there's a new`Component::export_index` method which enables performing a stringlookup and returning an index. This index can in turn be passed to`Instance::get_*` to skip the string lookup when exports are loaded. The`Instance::exports` API is then entirely removed and dismantled.The only piece remaining is the ability to load nested exports which isdone through an `Option` parameter to `Component::export_index`. Theway to load a nested instance is now to first lookup the instance with`None` as this parameter an then the instance itself is `Some` to lookup an export of that instance. This removes the need for arecursive-style lifetime-juggling API from wasmtime and in theory helpssimplify the usage of loading exports.* Update `bindgen!` generated structures for exportsThis commit updates the output of `bindgen!` to have a different setupfor exports of worlds to handle the changes from the previous commit.This introduces new `*Pre` structures which are generated alongside theexisting `Guest` structures for example. The `*Pre` versions contain`ComponentExportIndex` from the previous commit and serve as a path toaccelerating instantiation because all name lookups are skipped.* Update test expectations for `bindgen!`-generated output* Review comments* Fix doc link List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

3cd96e17 - Add `GetHost` to generated bindings for more flexible linking (#8448)

Mon, 13 May 2024 18:07:02 +0000

Add `GetHost` to generated bindings for more flexible linking (#8448)* Remove unused generated `add_root_to_linker` method* WIP: bindgen GetHost* Compile with Rust 1.78+Use as a guide of how to implement this by making the `GetHost` trait a bituglier.* Add an option to skip `&mut T -> T` implsAlso enable this for WASI crates since they do their own thing with`WasiView` for now. A future refactoring should be able to remove thisoption entirely and switch wasi crates to a new design of `WasiView`.* Update test expectations* Review comments* Undo temporary change* Handle some TODOs* Remove no-longer-relevant note* Fix wasmtime-wasi-http doc link---------Co-authored-by: Alex Crichton List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs

eea68f59 - bindgen: Commit expanded bindgen output for tests (#8558)

Tue, 07 May 2024 00:58:19 +0000

bindgen: Commit expanded bindgen output for tests (#8558)These outputs are checked in and verified to be fresh by a test so thatthey can be relied on for code review. List of files: /wasmtime-44.0.1/crates/component-macro/tests/expanded/multi-return.rs