Commit Graph

3 Commits

Author SHA1 Message Date
Alex Crichton
16804673a2 Support parsing the text format in wasmtime crate (#813)
* Support parsing the text format in `wasmtime` crate

This commit adds support to the `wasmtime::Module` type to parse the
text format. This is often quite convenient to support in testing or
tinkering with the runtime. Additionally the `wat` parser is pretty
lightweight and easy to add to builds, so it's relatively easy for us to
support as well!

The exact manner that this is now supported comes with a few updates to
the existing API:

* A new optional feature of the `wasmtime` crate, `wat`, has been added.
  This is enabled by default.
* The `Module::new` API now takes `impl AsRef<[u8]>` instead of just
  `&[u8]`, and when the `wat` feature is enabled it will attempt to
  interpret it either as a wasm binary or as the text format. Note that
  this check is quite cheap since you just check the first byte.
* A `Module::from_file` API was added as a convenience to parse a file
  from disk, allowing error messages for `*.wat` files on disk to be a
  bit nicer.
* APIs like `Module::new_unchecked` and `Module::validate` remain
  unchanged, they require the binary format to be called.

The intention here is to make this as convenient as possible for new
developers of the `wasmtime` crate. By changing the default behavior
though this has ramifications such as, for example, supporting the text
format implicitly through the C API now.

* Handle review comments

* Update more tests to avoid usage of `wat` crate

* Go back to unchecked for now in wasm_module_new

Looks like C# tests rely on this?
2020-01-24 14:20:51 -06:00
Alex Crichton
0bee67a852 Document and update the API of the externals.rs module (#812)
* Document and update the API of the `externals.rs` module

This commit ensures that all public methods and items are documented in
the `externals.rs` module, notably all external values that can be
imported and exported in WebAssembly. Along the way this also tidies up
the API and fixes a few bugs:

* `Global::new` now returns a `Result` and fails if the provided value
  does not match the type of the global.
* `Global::set` now returns a `Result` and fails if the global is either
  immutable or the provided value doesn't match the type of the global.
* `Table::new` now fails if the provided initializer does not match the
  element type.
* `Table::get` now returns `Option<Val>` instead of implicitly returning
  null.
* `Table::set` now returns `Result<()>`, returning an error on out of
  bounds or if the input type is of the wrong type.
* `Table::grow` now returns `Result<u32>`, returning the previous number
  of table elements if succesful or an error if the maximum is reached
  or the initializer value is of the wrong type. Additionally a bug was
  fixed here where if the wrong initializer was provided the table would
  be grown still, but initialization would fail.
* `Memory::data` was renamed to `Memory::data_unchecked_mut`.
  Additionally `Memory::data_unchecked` was added. Lots of caveats were
  written down about how using the method can go wrong.
* `Memory::grow` now returns `Result<u32>`, returning an error if growth
  fails or the number of pages previous the growth if successful.

* Run rustfmt

* Fix another test

* Update crates/api/src/externals.rs

Co-Authored-By: Sergei Pepyakin <s.pepyakin@gmail.com>

Co-authored-by: Sergei Pepyakin <s.pepyakin@gmail.com>
2020-01-17 09:43:35 -06:00
Alex Crichton
364fa994ed Move the C API to a separate crate (#818)
* Move the C API to a separate crate

This commit moves the C API from `crates/api/src/wasm.rs` to
`crates/capi/src/lib.rs` to be located in a separate crate. There's a
number of reasons for this:

* When a Rust program depends on the `wasmtime` crate, there's no need
  to compile in the C API.
* This should improve compile times of the `wasmtime` crate since it's
  not producing artifacts which aren't always used.
* The development of the C API can be guaranteed to only use the public
  API of the `wasmtime` crate itself.

Some CI pieces are tweaked and this overall shouldn't have much impact
on users, it's intended that it's a cleanup/speedup for developers!

* Disable rustdoc/tests for capi

* Review feedback

* Add back in accidentally deleted comment

* More renamings

* Try to fix dotnet build
2020-01-14 11:36:57 -08:00