3ce896f69d
Previously, all Wiggle-generated traits were generated with `&mut self` signatures. With the addition of the `mutable` configuration option to `from_witx!` and `wasmtime_integration!`, one can disable this, emitting instead traits that use `&self` (i.e., `mutable: false`). This change is helpful for implementing wasi-threads: WASI implementations with interior mutability will now be able to communitcate this to their Wiggle-generated code. The other side of this change is the `get_cx` closure passed to Wiggle's generated `add_to_linker` function. When `mutability` is set to `true` (default), the `get_cx` function takes a `&mut` data structure from the store and returns a corresponding `&mut` reference, usually to a field of the passed-in structure. When `mutability: false`, the `get_cx` closure will still take a `&mut` data structure but now will return a `&` reference.
wiggle-generate
This is a library crate that implements all of the component parts of
the wiggle proc-macro crate.
Code lives in a separate non-proc-macro crate so that it can be reused in
other settings, e.g. the lucet-wiggle crate.
Code generated by this crate should not have any references to a particular WebAssembly runtime or engine. It should instead expose traits that may be implemented by an engine. Today, it is consumed by both Lucet and Wasmtime.