Changes in matching.rs

1f16b28f - Refactor `String` usage in `wasmtime_environ::Module` (#12565)

Thu, 12 Feb 2026 21:27:05 +0000

Refactor `String` usage in `wasmtime_environ::Module` (#12565)* Refactor `String` usage in `wasmtime_environ::Module`Do not hold regular `String`s; instead use our own OOM-handling`wasmtime_core::alloc::String` or, even better, an interned `Atom` from the`StringPool`.Also avoid `IndexMap`, as it doesn't handle OOMs.* Use OOM-handling `IndexMap` in `wasmtime_environ::Module`* review feedback List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

ff33e949 - Do not re-export `anyhow!` in the `wasmtime::prelude` (#12298)

Fri, 09 Jan 2026 19:23:56 +0000

Do not re-export `anyhow!` in the `wasmtime::prelude` (#12298)We are trying to move to `format_err!` instead. List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

8fbe4c2c - Fix some panics compiling components and resources (#11798)

Mon, 06 Oct 2025 22:36:55 +0000

Fix some panics compiling components and resources (#11798)In working on bytecodealliance/wasm-tools#2335 I found that there's afew test cases in wasm-tools which Wasmtime was panicking to compile.The issues were all related to resource types and how information wasn'tregistered ahead of time before it was translated from wasmparser'srepresentation to Wasmtime's representation. The high-level cause forthis had to do with how component and instance types are handled, asopposed to concrete components or instances themselves. This waseffectively a hole in Wasmtime's translation process for componentswhich has never been filled out since the original implementation ofresources. The reason that this never came up before is:* Most components don't currently import or export a component itself.* Most components don't currently import or export component or instance types (as opposed to values).One of these was required to trigger this issue. The solutionimplemented in this commit is to plumb the concept of an "abstractresource" which is part of a type but not actually ever used at runtimeexcept for type equality during type reflection. This is expected tohave little-to-no impact on real-world components given that thesesituations are rarely occurring. List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.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/wasmtime/src/runtime/component/matching.rs

8fb9d189 - Remove `Stored` usage from `wasmtime::component::Instance` (#10913)

Tue, 03 Jun 2025 20:21:59 +0000

Remove `Stored` usage from `wasmtime::component::Instance` (#10913)* Remove mutability required on a number of component methodsPowered by previous refactorings it's possible to just take`&StoreOpaque` in these locations.* Move core instance map into `ComponentInstance`This commit moves the mapping from a `RuntimeInstanceIndex` to a`wasmtime::Instance` from `wasmtime::component::InstanceData` into theinternal `ComponentInstance` structure. This is done in preparation toremove `InstanceData` eventually.* Move `Component` to live in `ComponentInstance`Previously this lived in `InstanceData` but that's just a historicalartifact of the old `wasmtime` and `wasmtime-runtime` split. Nowadaysit's possible to store `Component` directly to further move informationout of `InstanceData`.* Move `InstanceData::imports` to `ComponentInstance`More preparation for the removal of `InstanceData` entirely.* Move lookup functions from `InstanceData` to `ComponentInstance`More prep for the removal of `InstanceData`.* Reduce some more reliance on `InstanceState`Just removing it from some type signatures to make future removaleasier.* Remove an unused result from a helper functionNo caller needs it, so go ahead and remove it.* Make `ComponentInstance::imports` privateThis moves some methods around and documents preexisting `unsafe`contracts to get this field private and prevent external access to it.* Remove `InstanceData` from `Instantiator`.Use `OwnedComponentInstance` instead.* Remove `InstanceData`, refactor `Instance`This commit refactors the representation of `component::Instance` to bepurely index-based to data already within a store. This makes creationof an `Instance` free compared to before where auxiliary data needed tobe created. Note that this doesn't actually change storage within a`Store` as instances are still there, it's just that now the storagelives in a non-`Stored`-related location. List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

90ac295e - Update Wasmtime to the 2024 Rust Edition (#10806)

Mon, 19 May 2025 16:40:55 +0000

Update Wasmtime to the 2024 Rust Edition (#10806)* Update Wasmtime to the 2024 Rust EditionNow that our MSRV supports the 2024 edition it's possible to make thisswitch. This commit moves Wasmtime to the 2024 Edition to keepup-to-date with Rust idioms and access many of the edition featuresexclusive to the 2024 edition.prtest:full* Reformat with the 2024 edition List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

39f49fe8 - wasmtime: remove Any-typing from the vm's representation of resource types table (#10607)

Wed, 16 Apr 2025 23:39:09 +0000

wasmtime: remove Any-typing from the vm's representation of resource types table (#10607)This any-typing is a left over escape hatch from the wasmtime /wasmtime-runtime divide, but now that the types all live in the samecrate we can eliminate the Any and just use the concrete typeeverywhere. List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

cb235ecf - Wasm GC: Fix an incorrect assertion and canonicalize types for runtime usage in ExternType::from_wasmtime (#10223)

Fri, 14 Feb 2025 17:03:26 +0000

Wasm GC: Fix an incorrect assertion and canonicalize types for runtime usage in ExternType::from_wasmtime (#10223)* Fix assertion in `PartialEq` for `RegisteredType` againIt is possible for two `WasmSubType`s to be equal to each other, as far as`derive(PartialEq)` is concerned, but still different from each other if theyare in different rec groups or even if they are at different indices within thesame rec group. The assertion mistakenly did not permit either of these,however.Fixes #9714* Canonicalize all types for runtime usage when creating `wasmtime::{Module,Component}`sRather than canonicalizing them on demand in functions like`{Func,Global,Table}Type::from_wasmtime` and other places. Instead, we do it inone place, up front, so that it is very unlikely we miss anything. Doing thisinvolves changing some things from `ModuleInternedTypeIndex`es to`EngineOrModuleTypeIndex`es in `wasmtime_environ`, which means that a bunch ofuses of those things need to unwrap the appropriate kind of type index at usagesites (e.g. compilation uses will unwrap `ModuleInternedTypeIndex`es, runtimeuses usage will unwrap `VMSharedTypeIndex`es). And it additionally requiredimplementing the `TypeTrace` trait for a handful of things to unlock theprovided `canonicalize_for_runtime_usage` trait method for those things.All this machinery is required to avoid an assertion failure in the regressiontest introduced in the previous commit, which was triggered because we werefailing to canonicalize type indices inside `ExternType`s for runtime usage onsome code paths. We shouldn't have to play that kind of whack-a-mole in thefuture, thanks to this new approach.* Fix a warning in no-default-features builds* Fix another warning in weird cfg builds List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

9bdb731a - Implement semver compatibility for exports (#8830)

Tue, 18 Jun 2024 18:08:43 +0000

Implement semver compatibility for exports (#8830)* Implement semver compatibility for exportsThis commit is an implementation of component model semver compatibilityfor export lookups. Previously in #7994 component imports were madesemver-aware to ensure that bumping version numbers would not be abreaking change. This commit implements the same feature for componentexports. This required some refactoring to move the definition of semvercompat around and the previous refactoring in #8786 enables frontloadingthis work to happen before instantiation.Closes #8395* Review comments* Fix tests List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

1512a954 - Add `anyhow` stuff to our internal `wasmtime` crate prelude (#8804)

Fri, 14 Jun 2024 15:24:12 +0000

Add `anyhow` stuff to our internal `wasmtime` crate prelude (#8804)* Add `anyhow` stuff to our internal `wasmtime` crate preludeWe use it basically everywhere and it is annoying to have to import.I also did an audit of existing `use` statements and removed the now-redundantones and replaced one-off imports with usage of the prelude, so that the preludeis available by default in more places.* Fix `cargo doc` List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

0e9121da - Fix some typos (#8641)

Thu, 16 May 2024 23:21:22 +0000

Fix some typos (#8641)* occurred* winch typos* tests typos* cli typos* fuzz typos* examples typos* docs typos* crates/wasmtime typos* crates/environ typos* crates/cranelift typos* crates/test-programs typos* crates/c-api typos* crates/cache typos* crates other typos* cranelift/codegen/src/isa typos* cranelift/codegen/src other typos* cranelift/codegen other typos* cranelift other typos* ci js typo* .github workflows typo* RELEASES typo* Fix clang-format documentation line---------Co-authored-by: Andrew Brown List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

81a89169 - Add support for `#![no_std]` to the `wasmtime` crate (#8533)

Sat, 04 May 2024 22:02:26 +0000

Add support for `#![no_std]` to the `wasmtime` crate (#8533)* Always fall back to custom platform for WasmtimeThis commit updates Wasmtime's platform support to no longer require anopt-in `RUSTFLAGS` `--cfg` flag to be specified. With `no_std` becomingofficially supported this should provide a better onboarding experiencewhere the fallback custom platform is used. This will cause linkererrors if the symbols aren't implemented and searching/googling shouldlead back to our docs/repo (eventually, hopefully).* Change Wasmtime's TLS state to a single pointerThis commit updates the management of TLS to rely on just a singlepointer rather than a pair of a pointer and a `bool`. Additionallymanagement of the TLS state is pushed into platform-specific modules toenable different means of managing it, namely the "custom" platform nowhas a C function required to implement TLS state for Wasmtime.* Delay conversion to `Instant` in atomic intrinsicsThe `Duration` type is available in `no_std` but the `Instant` type isnot. The intention is to only support the `threads` proposal if `std` isactive but to assist with this split push the `Duration` further intoWasmtime to avoid using a type that can't be mentioned in `no_std`.* Gate more parts of Wasmtime on the `profiling` featureMove `serde_json` to an optional dependency and gate the guest profilerentirely on the `profiling` feature.* Refactor conversion to `anyhow::Error` in `wasmtime-environ`Have a dedicated trait for consuming `self` in addition to a`Result`-friendly trait.* Gate `gimli` in Wasmtime on `addr2line`Cut down the dependency list if `addr2line` isn't enabled since thenthe dependency is not used. While here additionally lift the versionrequirement for `addr2line` up to the workspace level.* Update `bindgen!` to have `no_std`-compatible outputPull most types from Wasmtime's `__internal` module as the source oftruth.* Use an `Option` for `gc_store` instead of `OnceCell`No need for synchronization here when mutability is already available inthe necessary contexts.* Enable embedder-defined host feature detection* Add `#![no_std]` support to the `wasmtime` crateThis commit enables compiling the `runtime`, `gc`, and `component-model`features of the `wasmtime` crate on targets that do not have `std`. Thistags the crate as `#![no_std]` and then updates everything internally toimport from `core` or `alloc` and adapt for the various idioms. Thisended up requiring some relatively extensive changes, but nothing tootoo bad in the grand scheme of things.* Require `std` for the perfmap profiling agentprtest:full* Fix build on wasm* Fix windows build* Remove unused import* Fix Windows/Unix build without `std` feature* Fix some doc links* Remove unused import* Fix build of wasi-common in isolation* Fix no_std build on macos* Re-fix build* Fix standalone build of wasmtime-cli-flags* Resolve a merge conflict* Review comments* Remove unused import List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

72004aad - Turn the `wasmtime-runtime` crate into the `wasmtime::runtime::vm` module (#8501)

Tue, 30 Apr 2024 18:52:45 +0000

Turn the `wasmtime-runtime` crate into the `wasmtime::runtime::vm` module (#8501)* Expose `wasmtime-runtime` as `crate::runtime::vm` internally for the `wasmtime` crate* Rewrite uses of `wasmtime_runtime` to `crate::runtime::vm`* Remove dep on `wasmtime-runtime` from `wasmtime-cli`* Move the `wasmtime-runtime` crate into the `wasmtime::runtime::vm` module* Update labeler for merged crates* Fix `publish verify`prtest:full List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

67adf149 - Update nightly used in CI and fix warnings (#8416)

Fri, 19 Apr 2024 20:16:47 +0000

Update nightly used in CI and fix warnings (#8416)Fixes some warnings that nightly Rust has started emitting. List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

45a8da69 - Add a component type accessor for `Component` (#8078)

Mon, 11 Mar 2024 20:39:32 +0000

Add a component type accessor for `Component` (#8078)* Add a component type accessor for `Component`All the bits are already in place so all that's needed is to touch upsome docs and fixup a minor case uncovered through testing. Otherwisethis enables runtime reflection over the imports and exports of anuninstantiated component.* Run test through miri List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

57132f01 - Better error message for wrong import implementation (#7645)

Mon, 11 Mar 2024 18:18:25 +0000

Better error message for wrong import implementation (#7645)Signed-off-by: Ryan Levick List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

dd3f8d8b - Move dtor information from `ResourceAny` into a `Store` (#8061)

Fri, 08 Mar 2024 16:08:54 +0000

Move dtor information from `ResourceAny` into a `Store` (#8061)* Move dtor information from `ResourceAny` into a `Store`This commit moves the internals of the `ResourceAny` type related todestructors into the auxiliary data within a `Store`. This avoids theneed to carry around pointers with `ResourceAny` and additionally makesit easier to work with.As part of this commit this also updates the behavior of`ResourceAny::try_from_resource` to no longer need an `InstancePre` andtype information. This was required originally to get`ResourceAny::resource_drop` working to drop the host resource. Inretrospect I'm not sure if this was the best goal to achieve because`Resource` already has no destructor support and one of the morecommon use cases for the conversion is to simply turn around and give itback to a component where a component already has enough destructorinformation.In the end this should make both `ResourceAny` and `Resource` prettyclose to "just an index" which is easier to reason about when workingwith resources than carrying additional pointers.* Remove now-unneeded ResourceImportIndex machinery List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

868dfb95 - Make `component::Linker` semver-aware (#7994)

Tue, 27 Feb 2024 19:34:27 +0000

Make `component::Linker` semver-aware (#7994)This commit is an implementation of #7860 for Wasmtime where`wasmtime::component::Linker` is now "semver aware". This means that itassumes that hosts are always managing WIT interfaces in asemver-aare fashion meaning that semver-compatible upgrade exclusivelyadds functionality. This neatly fits into the idea of subtyping at theinstance-level where if a binary built against 0.2.0 only requests asubset of functionality from a runtime that provides 0.2.1, that shouldwork just fine.Specifically what this change does is:* For all names inserted into a `Linker` there might also be a "semver compatible name" which is registered as well. For example `..@1.0.0` is also registered as `..@1`.* Semver-compatible names are only provided for versions without a prerelease and with either a nonzero major or minor version number.* When looking up an item in the linker if no exact match is found then if a semver-compatible-name is available for the lookup key then that's consulted as well.This semantically means that if a components imports WASI 0.2.0 then aruntime which only provides WASI 0.2.1 will be able to instantiate thecomponent. Furthermore if a component imports WASI 0.2.1 but onlyimports the subset of WASI that was available in 0.2.0 then it will beinstantiable in a runtime that only supports 0.2.0.This implementation is intended to be a crucial part of the evolution toWASI to make it more seamless to upgrade WASI from both a host and guestperspective. This no longer requires everyone to upgrade to the sameversion all at the same time but instead decouples the upgradeschedules.Closes #7860 List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs

d4242001 - Support compilation-only build by adding a `runtime` feature (#7766)

Mon, 29 Jan 2024 15:51:43 +0000

Support compilation-only build by adding a `runtime` feature (#7766)* Add `runtime` feature to `wasmtime` crateThis feature can be disabled to build `wasmtime` only for compilation.This can be useful when cross-compiling, especially on a target thatcan't run wasmtime itself (e.g. `wasm32`).* prtest:full* don't round pages without runtime feature* fix async assertions* move profiling into runtime* enable runtime for wasmtime-wasi* enable runtime for c-api* fix build_artifacts in non-cache case* fix miri extensions* enable runtime for wast* enable runtime for explorer* support cranelift all-arch on wasm32* add doc links for `WeakEngine`* simplify lib runtime cfgs* move limits and resources to runtime* move stack to runtime* move coredump and debug to runtime* add runtime to coredump and async features* add wasm32 build job* combine engine modules* single compile mod* remove allow for macro paths* add comments List of files: /wasmtime-44.0.1/crates/wasmtime/src/runtime/component/matching.rs