Wasmtime

Released 2022-09-26

This is a patch release that incorporates a fix for a miscompilation of an
atomic-CAS operator on aarch64. The instruction is not usable from Wasmtime
with default settings, but may be used if the Wasm atomics extension is
enabled. The bug may also be reachable via other uses of Cranelift. Thanks to
bjorn3 for reporting and debugging this issue!

Fixed

* Fixed a miscompilation of `atomic_cas` on aarch64. The output register was
swapped with a temporary register in the register-allocator constraints.
[4959](https://github.com/bytecodealliance/wasmtime/pull/4959)
[4960](https://github.com/bytecodealliance/wasmtime/pull/4960)

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Added

* Stack walking has been reimplemented with frame pointers rather than with
native unwind information. This means that backtraces are feasible to capture
in performance-critical environments and in general stack walking is much
faster than before.
[4431](https://github.com/bytecodealliance/wasmtime/pull/4431)

* The WebAssembly `simd` proposal is now fully implemented for the s390x
backend.
[4427](https://github.com/bytecodealliance/wasmtime/pull/4427)

* Support for AArch64 has been added in the experimental native debuginfo
support that Wasmtime has.
[4468](https://github.com/bytecodealliance/wasmtime/pull/4468)

* Support building the C API of Wasmtime with CMake has been added.
[4369](https://github.com/bytecodealliance/wasmtime/pull/4369)

* Clarification was added to Wasmtime's documentation about "tiers of support"
for various features.
[4479](https://github.com/bytecodealliance/wasmtime/pull/4479)

Fixed

* Support for `filestat_get` has been improved for stdio streams in WASI.
[4531](https://github.com/bytecodealliance/wasmtime/pull/4531)

* Enabling the `vtune` feature no longer breaks builds on AArch64.
[4533](https://github.com/bytecodealliance/wasmtime/pull/4533)

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Released 2022-09-20

This release marks the official 1.0 release of Wasmtime and represents the
culmination of the work amongst over 300 contributors. Wasmtime has been
battle-tested in production through multiple embeddings for quite some time now
and we're confident in releasing a 1.0 version to signify the stability and
quality of the Wasmtime engine.

More information about Wasmtime's 1.0 release is on the [Bytecode Alliance's
blog][ba-blog] with separate posts on [Wasmtime's performance

Released 2022-08-20

This was a relatively quiet release in terms of user-facing features where most
of the work was around the internals of Wasmtime and Cranelift. Improvements
internally have been made along the lines of:

* Many more instructions are now implemented with ISLE instead of handwritten
lowerings.
* Many improvements to the cranelift-based fuzzing.
* Many platform improvements for s390x including full SIMD support, running
`rustc_codegen_cranelift` with features like `i128`, supporting more
ABIs, etc.
* Much more of the component model has been implemented and is now fuzzed.

Finally this release is currently scheduled to be the last `0.*` release of
Wasmtime. The upcoming release of Wasmtime on September 20 is planned to be
Wasmtime's 1.0 release. More information about what 1.0 means for Wasmtime is
available in the [1.0 RFC]

Released 2022-07-20.

Fixed

* An s390x-specific codegen bug in addition to a mistake introduced in the fix
of CVE-2022-31146 were fixed.
[4490](https://github.com/bytecodealliance/wasmtime/pull/4490)

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Released 2022-07-20

Added

* Initial support for shared memories and the `threads` WebAssembly proposal
has been added. Note that this feature is still experimental and not ready
for production use yet.
[4187](https://github.com/bytecodealliance/wasmtime/pull/4187)

* A new `Linker::define_unknown_imports_as_traps` method and
`--trap-unknown-imports` CLI flag have been added to conveniently support
running modules with imports that aren't dynamically called at runtime.
[4312](https://github.com/bytecodealliance/wasmtime/pull/4312)

* The VTune profiling strategy can now be selected through the C API.
[4316](https://github.com/bytecodealliance/wasmtime/pull/4316)

Changed

* Some methods on the `Config` structure now return `&mut Self` instead of
`Result<&mut Self>` since the validation is deferred until `Engine::new`:
`profiler`, `cranelift_flag_enable`, `cranelift_flag_set`, `max_wasm_stack`,
`async_stack_size`, and `strategy`.
[4252](https://github.com/bytecodealliance/wasmtime/pull/4252)
[4262](https://github.com/bytecodealliance/wasmtime/pull/4262)

* Parallel compilation of WebAssembly modules is now enabled in the C API by
default.
[4270](https://github.com/bytecodealliance/wasmtime/pull/4270)

* Implicit Cargo features of the `wasmtime` introduced through `optional`
dependencies may have been removed since namespaced features are now used.
It's recommended to only used the set of named `[features]` for Wasmtime.
[4293](https://github.com/bytecodealliance/wasmtime/pull/4293)

* Register allocation has fixed a few issues related to excessive memory usage
at compile time.
[4324](https://github.com/bytecodealliance/wasmtime/pull/4324)

Fixed

* A refactor of `Config` was made to fix an issue that the order of calls to `Config`
matters now, which may lead to unexpected behavior.
[4252](https://github.com/bytecodealliance/wasmtime/pull/4252)
[4262](https://github.com/bytecodealliance/wasmtime/pull/4262)

* Wasmtime has been fixed to work on SSE2-only x86\_64 platforms when the
`simd` feature is disabled in `Config`.
[4231](https://github.com/bytecodealliance/wasmtime/pull/4231)

* Generation of platform-specific unwinding information is disabled if
`wasm_backtrace` and `wasm_reference_types` are both disabled.
[4351](https://github.com/bytecodealliance/wasmtime/pull/4351)

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