Wasmtime Releases

0.15.0

Unreleased

Fix build errors in wasi-common on Windows.

Released 2020-03-24.

Lots of documentation of wasmtime has been updated. Be sure to check out the book and API documentation!
All wasmtime example programs are now in a top-level examples directory and are available in both C and Rust. #1286
A wasmtime::Linker type was added to conveniently link link wasm modules together and create instances that reference one another. #1384
Wasmtime now has "jitdump" support enabled by default which allows profiling wasm code on linux. #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
The bulk memory proposal has been fully implemented. #1264 #976
Virtual file support has been added to wasi-common. #701
The C API has been enhanced with a Wasmtime-specific wasmtime_wat2wasm to parse *.wat files via the C API. #1206

The wast and wasm2obj standalone binaries have been removed. They're available via the wasmtime wast and wasmtime wasm2obj subcommands. #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
Wasmtime no longer has a dependency on a C++ compiler. #1365
The Func::wrapN APIs have been consolidated into one Func::wrap API. #1363
The Callable trait has been removed and now Func::new takes a closure directly. #1363
The Cranelift repository has been merged into the Wasmtime repository.
Support for interface types has been temporarily removed. #1292
The exit code of the wasmtime CLI has changed if the program traps. #1274
The wasmtime CLI now logs to stderr by default and the -d flag has been renamed to --log-to-file. #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

Released 2020-02-26.

Support for the WebAssembly text annotations proposal has been added. #998
An initial C API for instantiating WASI modules has been added. #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
Initial support for profiling JIT code through perf jitdump has been added. #360
More CLI flags corresponding to proposed WebAssembly features have been added. #917

The wasmtime CLI as well as embedding API will optimize WebAssembly code by default now. #973 #988
The verifier pass in Cranelift is now no longer run by default when using the embedding API. #882

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
Automated releases for tags should be up and running again, along with automatic publication of the wasmtime Python package. #971