# Wasmtime Releases
--------------------------------------------------------------------------------
## Unreleased
## 0.28.0
Released 2021-06-09.
### Changed
* Breaking: Wasmtime's embedding API has been redesigned, as specified in [RFC
11]. Rust users can now enjoy easier times with `Send` and `Sync`, and all
users can now more clearly manage memory, especially in the C API. Language
embeddings have been updated to the new API as well.
[#2897](https://github.com/bytecodealliance/wasmtime/pull/2897)
[RFC 11]: https://github.com/bytecodealliance/rfcs/pull/11
### Added
* A new `InstancePre` type, created with `Linker::instantiate_pre`, has been
added to perform type-checking of an instance once and reduce the work done
for each instantiation of a module:
[#2962](https://github.com/bytecodealliance/wasmtime/pull/2962)
* Deserialization of a module can now optionally skip checking the wasmtime
version string:
[#2945](https://github.com/bytecodealliance/wasmtime/pull/2945)
* A method has been exposed to frontload per-thread initialization costs if the
latency of every last wasm call is important:
[#2946](https://github.com/bytecodealliance/wasmtime/pull/2946)
* Hooks have been added for entry/exit into wasm code to allow embeddings to
track time and other properties about execution in a wasm environment:
[#2952](https://github.com/bytecodealliance/wasmtime/pull/2952)
* A [C++ embedding of Wasmtime has been written][cpp].
[RFC 11]: https://github.com/bytecodealliance/rfcs/pull/11
[cpp]: https://github.com/bytecodealliance/wasmtime-cpp
### Fixed
* Multiple returns on macOS AArch64 have been fixed:
[#2956](https://github.com/bytecodealliance/wasmtime/pull/2956)
## 0.27.0
Released 2021-05-21.
### Security Fixes
* Fixed a security issue in Cranelift's x64 backend that could result in a heap
sandbox escape due to an incorrect sign-extension:
[#2913](https://github.com/bytecodealliance/wasmtime/issues/2913).
### Added
* Support for IBM z/Archiecture (`s390x`) machines in Cranelift and Wasmtime:
[#2836](https://github.com/bytecodealliance/wasmtime/pull/2836),
[#2837](https://github.com/bytecodealliance/wasmtime/pull/2837),
[#2838](https://github.com/bytecodealliance/wasmtime/pull/2838),
[#2843](https://github.com/bytecodealliance/wasmtime/pull/2843),
[#2854](https://github.com/bytecodealliance/wasmtime/pull/2854),
[#2870](https://github.com/bytecodealliance/wasmtime/pull/2870),
[#2871](https://github.com/bytecodealliance/wasmtime/pull/2871),
[#2872](https://github.com/bytecodealliance/wasmtime/pull/2872),
[#2874](https://github.com/bytecodealliance/wasmtime/pull/2874).
* Improved async support in wasi-common runtime:
[#2832](https://github.com/bytecodealliance/wasmtime/pull/2832).
* Added `Store::with_limits`, `StoreLimits`, and `ResourceLimiter` to the
Wasmtime API to help with enforcing resource limits at runtime. The
`ResourceLimiter` trait can be implemented by custom resource limiters to
decide if linear memories or tables can be grown.
* Added `allow-unknown-exports` option for the run command:
[#2879](https://github.com/bytecodealliance/wasmtime/pull/2879).
* Added API to notify that a `Store` has moved to a new thread:
[#2822](https://github.com/bytecodealliance/wasmtime/pull/2822).
* Documented guidance around using Wasmtime in multithreaded contexts:
[#2812](https://github.com/bytecodealliance/wasmtime/pull/2812).
In the future, the Wasmtime API will change to allow some of its core types
to be Send/Sync; see the in-progress
[#2897](https://github.com/bytecodealliance/wasmtime/pull/2897) for details.
* Support calls from native code to multiple-return-value functions:
[#2806](https://github.com/bytecodealliance/wasmtime/pull/2806).
### Changed
* Breaking: `Memory::new` has been changed to return `Result` as creating a
host memory object is now a fallible operation when the initial size of
the memory exceeds the store limits.
### Fixed
* Many instruction selection improvements on x64 and aarch64:
[#2819](https://github.com/bytecodealliance/wasmtime/pull/2819),
[#2828](https://github.com/bytecodealliance/wasmtime/pull/2828),
[#2823](https://github.com/bytecodealliance/wasmtime/pull/2823),
[#2862](https://github.com/bytecodealliance/wasmtime/pull/2862),
[#2886](https://github.com/bytecodealliance/wasmtime/pull/2886),
[#2889](https://github.com/bytecodealliance/wasmtime/pull/2889),
[#2905](https://github.com/bytecodealliance/wasmtime/pull/2905).
* Improved performance of Wasmtime runtime substantially:
[#2811](https://github.com/bytecodealliance/wasmtime/pull/2811),
[#2818](https://github.com/bytecodealliance/wasmtime/pull/2818),
[#2821](https://github.com/bytecodealliance/wasmtime/pull/2821),
[#2847](https://github.com/bytecodealliance/wasmtime/pull/2847),
[#2900](https://github.com/bytecodealliance/wasmtime/pull/2900).
* Fixed WASI issue with file metadata on Windows:
[#2884](https://github.com/bytecodealliance/wasmtime/pull/2884).
* Fixed an issue with debug info and an underflowing (trapping) offset:
[#2866](https://github.com/bytecodealliance/wasmtime/pull/2866).
* Fixed an issue with unwind information in the old x86 backend:
[#2845](https://github.com/bytecodealliance/wasmtime/pull/2845).
* Fixed i32 spilling in x64 backend:
[#2840](https://github.com/bytecodealliance/wasmtime/pull/2840).
## 0.26.0
Released 2021-04-05.
### Added
* Added the `wasmtime compile` command to support AOT compilation of Wasm
modules. This adds the `Engine::precompile_module` method. Also added the
`Config::target` method to change the compilation target of the
configuration. This can be used in conjunction with
`Engine::precompile_module` to target a different host triple than the
current one.
[#2791](https://github.com/bytecodealliance/wasmtime/pull/2791)
* Support for macOS on aarch64 (Apple M1 Silicon), including Apple-specific
calling convention details and unwinding/exception handling using Mach ports.
[#2742](https://github.com/bytecodealliance/wasmtime/pull/2742),
[#2723](https://github.com/bytecodealliance/wasmtime/pull/2723)
* A number of SIMD instruction implementations in the new x86-64 backend.
[#2771](https://github.com/bytecodealliance/wasmtime/pull/2771)
* Added the `Config::cranelift_flag_enable` method to enable setting Cranelift
boolean flags or presets in a config.
* Added CLI option `--cranelift-enable` to enable boolean settings and ISA presets.
* Deduplicate function signatures in Wasm modules.
[#2772](https://github.com/bytecodealliance/wasmtime/pull/2772)
* Optimize overheads of calling into Wasm functions.
[#2757](https://github.com/bytecodealliance/wasmtime/pull/2757),
[#2759](https://github.com/bytecodealliance/wasmtime/pull/2759)
* Improvements related to Module Linking: compile fewer trampolines;
[#2774](https://github.com/bytecodealliance/wasmtime/pull/2774)
* Re-export sibling crates from `wasmtime-wasi` to make embedding easier
without needing to match crate versions.
[#2776](https://github.com/bytecodealliance/wasmtime/pull/2776)
### Changed
* Switched the default compiler backend on x86-64 to Cranelift's new backend.
This should not have any user-visible effects other than possibly runtime
performance improvements. The old backend is still available with the
`old-x86-backend` feature flag to the `cranelift-codegen` or `wasmtime`
crates, or programmatically with `BackendVariant::Legacy`. We plan to
maintain the old backend for at least one more release and ensure it works on
CI.
[#2718](https://github.com/bytecodealliance/wasmtime/pull/2718)
* Breaking: `Module::deserialize` has been removed in favor of `Module::new`.
* Breaking: `Config::cranelift_clear_cpu_flags` was removed. Use `Config::target`
to clear the CPU flags for the host's target.
* Breaking: `Config::cranelift_other_flag` was renamed to `Config::cranelift_flag_set`.
* CLI changes:
* Wasmtime CLI options to enable WebAssembly features have been replaced with
a singular `--wasm-features` option. The previous options are still
supported, but are not displayed in help text.
* Breaking: the CLI option `--cranelift-flags` was changed to
`--cranelift-set`.
* Breaking: the CLI option `--enable-reference-types=false` has been changed
to `--wasm-features=-reference-types`.
* Breaking: the CLI option `--enable-multi-value=false` has been changed to
`--wasm-features=-multi-value`.
* Breaking: the CLI option `--enable-bulk-memory=false` has been changed to
`--wasm-features=-bulk-memory`.
* Improved error-reporting in wiggle.
[#2760](https://github.com/bytecodealliance/wasmtime/pull/2760)
* Make WASI sleeping fallible (some systems do not support sleep).
[#2756](https://github.com/bytecodealliance/wasmtime/pull/2756)
* WASI: Support `poll_oneoff` with a sleep.
[#2753](https://github.com/bytecodealliance/wasmtime/pull/2753)
* Allow a `StackMapSink` to be passed when defining functions with
`cranelift-module`.
[#2739](https://github.com/bytecodealliance/wasmtime/pull/2739)
* Some refactoring in new x86-64 backend to prepare for VEX/EVEX (e.g.,
AVX-512) instruction encodings to be supported.
[#2799](https://github.com/bytecodealliance/wasmtime/pull/2799)
### Fixed
* Fixed a corner case in `srem` (signed remainder) in the new x86-64 backend:
`INT_MIN % -1` should return `0`, rather than trapping. This only occurred
when `avoid_div_traps == false` was set by the embedding.
[#2763](https://github.com/bytecodealliance/wasmtime/pull/2763)
* Fixed a memory leak of the `Store` when an instance traps.
[#2803](https://github.com/bytecodealliance/wasmtime/pull/2803)
* Some fuzzing-related fixes.
[#2788](https://github.com/bytecodealliance/wasmtime/pull/2788),
[#2770](https://github.com/bytecodealliance/wasmtime/pull/2770)
* Fixed memory-initialization bug in uffd allocator that could copy into the
wrong destination under certain conditions. Does not affect the default
wasmtime instance allocator.
[#2801](https://github.com/bytecodealliance/wasmtime/pull/2801)
* Fix printing of float values from the Wasmtime CLI.
[#2797](https://github.com/bytecodealliance/wasmtime/pull/2797)
* Remove the ability for the `Linker` to instantiate modules with duplicate
import strings of different types.
[#2789](https://github.com/bytecodealliance/wasmtime/pull/2789)
## 0.25.0
Released 2021-03-16.
### Added
* An implementation of a pooling instance allocator, optionally backed by
`userfaultfd` on Linux, was added to improve the performance of embeddings
that instantiate a large number of instances continuously.
[#2518](https://github.com/bytecodealliance/wasmtime/pull/2518)
* Host functions can now be defined on `Config` to share the function across all
`Store` objects connected to an `Engine`. This can improve the time it takes
to instantiate instances in a short-lived `Store`.
[#2625](https://github.com/bytecodealliance/wasmtime/pull/2625)
* The `Store` object now supports having typed values attached to it which can
be retrieved from host functions.
[#2625](https://github.com/bytecodealliance/wasmtime/pull/2625)
* The `wiggle` code generator now supports `async` host functions.
[#2701](https://github.com/bytecodealliance/wasmtime/pull/2701)
### Changed
* The `Func::getN{,_async}` APIs have all been removed in favor of a new
`Func::typed` API which should be more compact in terms of API surface area as
well as more flexible in how it can be used.
[#2719](https://github.com/bytecodealliance/wasmtime/pull/2719)
* `Engine::new` has been changed from returning `Engine` to returning
`anyhow::Result<Engine>`. Callers of `Engine::new` will need to be updated to
use the `?` operator on the return value or otherwise unwrap the result to get
the `Engine`.
### Fixed
* Interpretation of timestamps in `poll_oneoff` for WASI have been fixed to
correctly use nanoseconds instead of microseconds.
[#2717](https://github.com/bytecodealliance/wasmtime/pull/2717)
## 0.24.0
Released 2021-03-04.
### Added
* Implement support for `async` functions in Wasmtime
[#2434](https://github.com/bytecodealliance/wasmtime/pull/2434)
### Fixed
* Fix preservation of the sigaltstack on macOS
[#2676](https://github.com/bytecodealliance/wasmtime/pull/2676)
* Fix incorrect semver dependencies involving fs-set-times.
[#2705](https://github.com/bytecodealliance/wasmtime/pull/2705)
* Fix some `i128` shift-related bugs in x64 backend.
[#2682](https://github.com/bytecodealliance/wasmtime/pull/2682)
* Fix incomplete trap metadata due to multiple traps at one address
[#2685](https://github.com/bytecodealliance/wasmtime/pull/2685)
## 0.23.0
Released 2021-02-16.
### Added
* Support for limiting WebAssembly execution with fuel was added, including
support in the C API.
[#2611](https://github.com/bytecodealliance/wasmtime/pull/2611)
[#2643](https://github.com/bytecodealliance/wasmtime/pull/2643)
* Wasmtime now has more knobs for limiting memory and table allocations
[#2617](https://github.com/bytecodealliance/wasmtime/pull/2617)
* Added a method to share `Config` across machines
[#2608](https://github.com/bytecodealliance/wasmtime/pull/2608)
* Added a safe memory read/write API
[#2528](https://github.com/bytecodealliance/wasmtime/pull/2528)
* Added support for the experimental wasi-crypto APIs
[#2597](https://github.com/bytecodealliance/wasmtime/pull/2597)
* Added an instance limit to `Config`
[#2593](https://github.com/bytecodealliance/wasmtime/pull/2593)
* Implemented module-linking's outer module aliases
[#2590](https://github.com/bytecodealliance/wasmtime/pull/2590)
* Cranelift now supports 128-bit operations for the new x64 backend.
[#2539](https://github.com/bytecodealliance/wasmtime/pull/2539)
* Cranelift now has detailed debug-info (DWARF) support in new backends (initially x64).
[#2565](https://github.com/bytecodealliance/wasmtime/pull/2565)
* Cranelift now uses the `POPCNT`, `TZCNT`, and `LZCNT`, as well as SSE 4.1
rounding instructions on x64 when available.
* Cranelift now uses the `CNT`, instruction on aarch64 when available.
### Changed
* A new WASI implementation built on the new
[`cap-std`](https://github.com/bytecodealliance/cap-std) crate was added,
replacing the previous implementation. This brings improved robustness,
portability, and performance.
* `wasmtime_wasi::WasiCtxBuilder` moved to
`wasi_cap_std_sync::WasiCtxBuilder`.
* The WebAssembly C API is updated, with a few minor API changes
[#2579](https://github.com/bytecodealliance/wasmtime/pull/2579)
### Fixed
* Fixed a panic in WASI `fd_readdir` on large directories
[#2620](https://github.com/bytecodealliance/wasmtime/pull/2620)
* Fixed a memory leak with command modules
[#2017](https://github.com/bytecodealliance/wasmtime/pull/2017)
--------------------------------------------------------------------------------
## 0.22.0
Released 2021-01-07.
### Added
* Experimental support for [the module-linking
proposal](https://github.com/WebAssembly/module-linking) was
added. [#2094](https://github.com/bytecodealliance/wasmtime/pull/2094)
* Added support for [the reference types
proposal](https://webassembly.github.io/reference-types) on the aarch64
architecture. [#2410](https://github.com/bytecodealliance/wasmtime/pull/2410)
* Experimental support for [wasi-nn](https://github.com/WebAssembly/wasi-nn) was
added. [#2208](https://github.com/bytecodealliance/wasmtime/pull/2208)
### Changed
### Fixed
* Fixed an issue where the `select` instruction didn't accept `v128` SIMD
operands. [#2391](https://github.com/bytecodealliance/wasmtime/pull/2391)
* Fixed an issue where Wasmtime could potentially use the wrong stack map during
GCs, leading to a
panic. [#2396](https://github.com/bytecodealliance/wasmtime/pull/2396)
* Fixed an issue where if a host-defined function erroneously returned a value
from a different store, that value would be
leaked. [#2424](https://github.com/bytecodealliance/wasmtime/pull/2424)
* Fixed a bug where in certain cases if a module's instantiation failed, it
could leave trampolines in the store that referenced the no-longer-valid
instance. These trampolines could be reused in future instantiations, leading
to use after free bugs.
[#2408](https://github.com/bytecodealliance/wasmtime/pull/2408)
* Fixed a miscompilation on aarch64 where certain instructions would read `SP`
instead of the zero register. This could only affect you if you explicitly
enabled the Wasm SIMD
proposal. [#2548](https://github.com/bytecodealliance/wasmtime/pull/2548)
--------------------------------------------------------------------------------
## 0.21.0
Released 2020-11-05.
### Added
* Experimental support for the multi-memory proposal was added.
[#2263](https://github.com/bytecodealliance/wasmtime/pull/2263)
* The `Trap::trap_code` API enables learning what kind of trap was raised.
[#2309](https://github.com/bytecodealliance/wasmtime/pull/2309)
### Changed
* WebAssembly module validation is now parallelized.
[#2059](https://github.com/bytecodealliance/wasmtime/pull/2059)
* Documentation is now available at docs.wasmtime.dev.
[#2317](https://github.com/bytecodealliance/wasmtime/pull/2317)
* Windows now compiles like other platforms with a huge guard page instead of
having its own custom limit which made modules compile and run more slowly.
[#2326](https://github.com/bytecodealliance/wasmtime/pull/2326)
* The size of the cache entry for serialized modules has been greatly reduced.
[#2321](https://github.com/bytecodealliance/wasmtime/pull/2321)
[#2322](https://github.com/bytecodealliance/wasmtime/pull/2322)
[#2324](https://github.com/bytecodealliance/wasmtime/pull/2324)
[#2325](https://github.com/bytecodealliance/wasmtime/pull/2325)
* The `FuncType` API constructor and accessors are now iterator-based.
[#2365](https://github.com/bytecodealliance/wasmtime/pull/2365)
### Fixed
* A panic in compiling reference-types-using modules has been fixed.
[#2350](https://github.com/bytecodealliance/wasmtime/pull/2350)
--------------------------------------------------------------------------------
## 0.20.0
Released 2020-09-23.
### Added
* Support for explicitly serializing and deserializing compiled wasm modules has
been added.
[#2020](https://github.com/bytecodealliance/wasmtime/pull/2020)
* A `wasmtime_store_gc` C API was added to run GC for `externref`.
[#2052](https://github.com/bytecodealliance/wasmtime/pull/2052)
* Support for atomics in Cranelift has been added. Support is not fully
implemented in Wasmtime at this time, however.
[#2077](https://github.com/bytecodealliance/wasmtime/pull/2077)
* The `Caller::get_export` function is now implemented for `Func` references as
well.
[#2108](https://github.com/bytecodealliance/wasmtime/pull/2108)
### Fixed
* Leaks in the C API have been fixed.
[#2040](https://github.com/bytecodealliance/wasmtime/pull/2040)
* The `wasm_val_copy` C API has been fixed for reference types.
[#2041](https://github.com/bytecodealliance/wasmtime/pull/2041)
* Fix a panic with `Func::new` and reference types when the store doesn't have
reference types enabled.
[#2039](https://github.com/bytecodealliance/wasmtime/pull/2039)
--------------------------------------------------------------------------------
## 0.19.0
Released 2020-07-14.
### Added
* The [WebAssembly reference-types proposal][reftypes] is now supported in
Wasmtime and the C API.
[#1832](https://github.com/bytecodealliance/wasmtime/pull/1832),
[#1882](https://github.com/bytecodealliance/wasmtime/pull/1882),
[#1894](https://github.com/bytecodealliance/wasmtime/pull/1894),
[#1901](https://github.com/bytecodealliance/wasmtime/pull/1901),
[#1923](https://github.com/bytecodealliance/wasmtime/pull/1923),
[#1969](https://github.com/bytecodealliance/wasmtime/pull/1969),
[#1973](https://github.com/bytecodealliance/wasmtime/pull/1973),
[#1982](https://github.com/bytecodealliance/wasmtime/pull/1982),
[#1984](https://github.com/bytecodealliance/wasmtime/pull/1984),
[#1991](https://github.com/bytecodealliance/wasmtime/pull/1991),
[#1996](https://github.com/bytecodealliance/wasmtime/pull/1996)
* The [WebAssembly simd proposal's][simd] spec tests now pass in Wasmtime.
[#1765](https://github.com/bytecodealliance/wasmtime/pull/1765),
[#1876](https://github.com/bytecodealliance/wasmtime/pull/1876),
[#1941](https://github.com/bytecodealliance/wasmtime/pull/1941),
[#1957](https://github.com/bytecodealliance/wasmtime/pull/1957),
[#1990](https://github.com/bytecodealliance/wasmtime/pull/1990),
[#1994](https://github.com/bytecodealliance/wasmtime/pull/1994)
* Wasmtime can now be compiled without the usage of threads for parallel
compilation, although this is still enabled by default.
[#1903](https://github.com/bytecodealliance/wasmtime/pull/1903)
* The C API is [now
documented](https://bytecodealliance.github.io/wasmtime/c-api/).
[#1928](https://github.com/bytecodealliance/wasmtime/pull/1928),
[#1959](https://github.com/bytecodealliance/wasmtime/pull/1959),
[#1968](https://github.com/bytecodealliance/wasmtime/pull/1968)
* A `wasmtime_linker_get_one_by_name` function was added to the C API.
[#1897](https://github.com/bytecodealliance/wasmtime/pull/1897)
* A `wasmtime_trap_exit_status` function was added to the C API.
[#1912](https://github.com/bytecodealliance/wasmtime/pull/1912)
* Compilation for the `aarch64-linux-android` target should now work, although
keep in mind this platform is not fully tested still.
[#2002](https://github.com/bytecodealliance/wasmtime/pull/2002)
[reftypes]: https://github.com/WebAssembly/reference-types
### Fixed
* Runtime warnings when using Wasmtime on musl have been fixed.
[#1914](https://github.com/bytecodealliance/wasmtime/pull/1914)
* A bug affecting Windows unwind information with functions that have spilled
floating point registers has been fixed.
[#1983](https://github.com/bytecodealliance/wasmtime/pull/1983)
### Changed
* Wasmtime's default branch and development now happens on the `main` branch
instead of `master`.
[#1924](https://github.com/bytecodealliance/wasmtime/pull/1924)
### Removed
* The "host info" support in the C API has been removed since it was never fully
or correctly implemented.
[#1922](https://github.com/bytecodealliance/wasmtime/pull/1922)
* Support for the `*_same` functions in the C API has been removed in the same
vein as the host info APIs.
[#1926](https://github.com/bytecodealliance/wasmtime/pull/1926)
--------------------------------------------------------------------------------
## 0.18.0
Release 2020-06-09.
### Added
The `WasmTy` trait is now implemented for `u32` and `u64`.
[#1808](https://github.com/bytecodealliance/wasmtime/pull/1808)
--------------------------------------------------------------------------------
## 0.17.0
Released 2020-06-01.
### Added
* The [Commands and Reactors ABI] is now supported in the Rust API. `Linker::module`
loads a module and automatically handles Commands and Reactors semantics.
[#1565](https://github.com/bytecodealliance/wasmtime/pull/1565)
[Commands and Reactors ABI]: https://github.com/WebAssembly/WASI/blob/master/design/application-abi.md#current-unstable-abi
The `Table::grow` function now returns the previous table size, making it consistent
with the `table.grow` instruction.
[#1653](https://github.com/bytecodealliance/wasmtime/pull/1653)
New Wasmtime-specific C APIs for working with tables were added which provide more
detailed error information and which make growing a table more consistent with the
`table.grow` instruction as well.
[#1654](https://github.com/bytecodealliance/wasmtime/pull/1654)
The C API now includes support for enabling logging in Wasmtime.
[#1737](https://github.com/bytecodealliance/wasmtime/pull/1737)
### Changed
The WASI `proc_exit` function no longer exits the host process. It now unwinds the
callstack back to the wasm entrypoint, and the exit value is available from the
`Trap::i32_exit_status` method.
[#1646](https://github.com/bytecodealliance/wasmtime/pull/1646)
The WebAssembly [multi-value](https://github.com/WebAssembly/multi-value/) proposal
is now enabled by default.
[#1667](https://github.com/bytecodealliance/wasmtime/pull/1667)
The Rust API does not require a store provided during `Module::new` operation. The `Module` can be send accross threads and instantiate for a specific store. The `Instance::new` now requires the store.
[#1761](https://github.com/bytecodealliance/wasmtime/pull/1761)
--------------------------------------------------------------------------------
## 0.16.0
Released 2020-04-29.
### Added
* The `Instance` struct has new accessors, `get_func`, `get_table`,
`get_memory`, and `get_global` for quickly looking up exported
functions, tables, memories, and globals by name.
[#1524](https://github.com/bytecodealliance/wasmtime/pull/1524)
* The C API has a number of new `wasmtime_*` functions which return error
objects to get detailed error information when an API fails.
[#1467](https://github.com/bytecodealliance/wasmtime/pull/1467)
* Users now have fine-grained control over creation of instances of `Memory`
with a new `MemoryCreator` trait.
[#1400](https://github.com/bytecodealliance/wasmtime/pull/1400)
* Go bindings for Wasmtime are [now available][go-bindings].
[#1481](https://github.com/bytecodealliance/wasmtime/pull/1481)
* APIs for looking up values in a `Linker` have been added.
[#1480](https://github.com/bytecodealliance/wasmtime/pull/1480)
* Preliminary support for AArch64, also known as ARM64.
[#1581](https://github.com/bytecodealliance/wasmtime/pull/1581)
[go-bindings]: https://github.com/bytecodealliance/wasmtime-go
### Changed
* `Instance::exports` now returns `Export` objects which contain
the `name`s of the exports in addition to their `Extern` definitions,
so it's no longer necessary to use `Module::exports` to obtain the
export names.
[#1524](https://github.com/bytecodealliance/wasmtime/pull/1524)
* The `Func::call` API has changed its error type from `Trap` to `anyhow::Error`
to distinguish between wasm traps and runtime violations (like the wrong
number of parameters).
[#1467](https://github.com/bytecodealliance/wasmtime/pull/1467)
* A number of `wasmtime_linker_*` and `wasmtime_config_*` C APIs have new type
signatures which reflect returning errors.
[#1467](https://github.com/bytecodealliance/wasmtime/pull/1467)
* Bindings for .NET have moved to
https://github.com/bytecodealliance/wasmtime-dotnet.
[#1477](https://github.com/bytecodealliance/wasmtime/pull/1477)
* Passing too many imports to `Instance::new` is now considered an error.
[#1478](https://github.com/bytecodealliance/wasmtime/pull/1478)
### Fixed
* Spurious segfaults due to out-of-stack conditions when handling signals have
been fixed.
[#1315](https://github.com/bytecodealliance/wasmtime/pull/1315)
--------------------------------------------------------------------------------
## 0.15.0
Released 2020-03-31.
### Fixed
Full release produced for all artifacts to account for hiccups in 0.13.0 and
0.14.0.
--------------------------------------------------------------------------------
## 0.14.0
*This version ended up not getting a full release*
### Fixed
Fix build errors in wasi-common on Windows.
--------------------------------------------------------------------------------
## 0.13.0
Released 2020-03-24.
### Added
* Lots of documentation of `wasmtime` has been updated. Be sure to check out the
[book](https://bytecodealliance.github.io/wasmtime/) and [API
documentation](https://bytecodealliance.github.io/wasmtime/api/wasmtime/)!
* All wasmtime example programs are now in a top-level `examples` directory and
are available in both C and Rust.
[#1286](https://github.com/bytecodealliance/wasmtime/pull/1286)
* A `wasmtime::Linker` type was added to conveniently link link wasm modules
together and create instances that reference one another.
[#1384](https://github.com/bytecodealliance/wasmtime/pull/1384)
* Wasmtime now has "jitdump" support enabled by default which allows [profiling
wasm code on linux][jitdump].
[#1310](https://github.com/bytecodealliance/wasmtime/pull/1310)
* The `wasmtime::Caller` type now exists as a first-class way to access the
caller's exports, namely memory, when implementing host APIs. This can be the
first argument of functions defined with `Func::new` or `Func::wrap` which
allows easily implementing methods which take a pointer into wasm memory. Note
that this only works for accessing the caller's `Memory` for now and it must
be exported. This will eventually be replaced with a more general-purpose
mechanism like interface types.
[#1290](https://github.com/bytecodealliance/wasmtime/pull/1290)
* The bulk memory proposal has been fully implemented.
[#1264](https://github.com/bytecodealliance/wasmtime/pull/1264)
[#976](https://github.com/bytecodealliance/wasmtime/pull/976)
* Virtual file support has been added to `wasi-common`.
[#701](https://github.com/bytecodealliance/wasmtime/pull/701)
* The C API has been enhanced with a Wasmtime-specific `wasmtime_wat2wasm` to
parse `*.wat` files via the C API.
[#1206](https://github.com/bytecodealliance/wasmtime/pull/1206)
[jitdump]: https://bytecodealliance.github.io/wasmtime/examples-profiling.html
### Changed
* The `wast` and `wasm2obj` standalone binaries have been removed. They're
available via the `wasmtime wast` and `wasmtime wasm2obj` subcommands.
[#1372](https://github.com/bytecodealliance/wasmtime/pull/1372)
* The `wasi-common` crate now uses the new `wiggle` crate to auto-generate a
trait which is implemented for the current wasi snapshot.
[#1202](https://github.com/bytecodealliance/wasmtime/pull/1202)
* Wasmtime no longer has a dependency on a C++ compiler.
[#1365](https://github.com/bytecodealliance/wasmtime/pull/1365)
* The `Func::wrapN` APIs have been consolidated into one `Func::wrap` API.
[#1363](https://github.com/bytecodealliance/wasmtime/pull/1363)
* The `Callable` trait has been removed and now `Func::new` takes a closure
directly.
[#1363](https://github.com/bytecodealliance/wasmtime/pull/1363)
* The Cranelift repository has been merged into the Wasmtime repository.
* Support for interface types has been temporarily removed.
[#1292](https://github.com/bytecodealliance/wasmtime/pull/1292)
* The exit code of the `wasmtime` CLI has changed if the program traps.
[#1274](https://github.com/bytecodealliance/wasmtime/pull/1274)
* The `wasmtime` CLI now logs to stderr by default and the `-d` flag has been
renamed to `--log-to-file`.
[#1266](https://github.com/bytecodealliance/wasmtime/pull/1266)
* Values cannot cross `Store` objects, meaning you can't instantiate a module
with values from different stores nor pass values from different stores into
methods.
[#1016](https://github.com/bytecodealliance/wasmtime/pull/1016)
--------------------------------------------------------------------------------
## 0.12.0
Released 2020-02-26.
### Added
* Support for the [WebAssembly text annotations proposal][annotations-proposal]
has been added.
[#998](https://github.com/bytecodealliance/wasmtime/pull/998)
* An initial C API for instantiating WASI modules has been added.
[#977](https://github.com/bytecodealliance/wasmtime/pull/977)
* A new suite of `Func::getN` functions have been added to the `wasmtime` API to
call statically-known function signatures in a highly optimized fashion.
[#955](https://github.com/bytecodealliance/wasmtime/pull/955)
* Initial support for profiling JIT code through perf jitdump has been added.
[#360](https://github.com/bytecodealliance/wasmtime/pull/360)
* More CLI flags corresponding to proposed WebAssembly features have been added.
[#917](https://github.com/bytecodealliance/wasmtime/pull/917)
[annotations-proposal]: https://github.com/webassembly/annotations
### Changed
* The `wasmtime` CLI as well as embedding API will optimize WebAssembly code by
default now.
[#973](https://github.com/bytecodealliance/wasmtime/pull/973)
[#988](https://github.com/bytecodealliance/wasmtime/pull/988)
* The `verifier` pass in Cranelift is now no longer run by default when using
the embedding API.
[#882](https://github.com/bytecodealliance/wasmtime/pull/882)
### Fixed
* Code caching now accurately accounts for optimization levels, ensuring that if
you ask for optimized code you're not accidentally handed unoptimized code
from the cache.
[#974](https://github.com/bytecodealliance/wasmtime/pull/974)
* Automated releases for tags should be up and running again, along with
automatic publication of the `wasmtime` Python package.
[#971](https://github.com/bytecodealliance/wasmtime/pull/971)