Redesign function configuration in `bindgen!` (#11328)

* Redesign function configuration in `bindgen!`

This commit is a redesign of how function-level configuration works in
Wasmtime's `bindgen!` m

Redesign function configuration in `bindgen!` (#11328)

* Redesign function configuration in `bindgen!`

This commit is a redesign of how function-level configuration works in
Wasmtime's `bindgen!` macro. The main goal of this redesign is to
better support WASIp3 and component model async functions. Prior to this
redesign there was a mish mash of mechanisms to configure behavior of
imports/exports:

* The `async` configuration could turn everything async, nothing async,
only some imports async, or everything except some imports async.

* The `concurrent_{imports,exports}` keys were required to explicitly
opt-in to component model async signatures and applied to all
imports/exports.

* The `trappable_imports` configuration would indicate a list of imports
allowed to trap and it had special configuration for everything,
nothing, and only a certain list.

* The `tracing` and `verbose_tracing` keys could be applied to either
nothing or all functions.

Overall the previous state of configuration in `bindgen!` was clearly a
hodgepodge of systems that organically grew over time. In my personal
opinion it was in dire need of a refresh to take into account how
component-model-async ended up being implemented as well as
consolidating the one-off systems amongst all of these configuration
keys. A major motivation of this redesign, for example, was to inherit
behavior from WIT files by default. An `async` function in WIT should
not require `concurrent_*` keys to be configured, but rather it should
generate correct bindings by default.

In this commit, all of the above keys were removed. All keys have been
replaced with `imports` and `exports` configuration keys. Each behaves
the same way and looks like so:

bindgen!({
// ...
imports: {
// enable tracing for just this function
"my:local/interface/func": tracing,

// enable verbose tracing for just this function
"my:local/interface/other-func": tracing | verbose_tracing,

// this is blocking in WIT, but generate async bindings for
// it
"my:local/interface/[method]io.block": async,

// like above, but use "concurrent" bindings which have
// access to the store.
"my:local/interface/[method]io.block-again": async | store,

// everything else is, by default, trappable
default: trappable,
},
});

Effectively all the function-level configuration items are now bitflags.
These bitflags are by default inherited from the WIT files itself (e.g.
`async` functions are `async | store` by default). Further configuration
is then layered on top at the desires of the embedder. Supported keys are:

* `async` - this means that a Rust-level `async` function should be
generated. This is either `CallStyle::Async` or
`CallStyle::Concurrent` as it was prior, depending on ...

* `store` - this means that the generated function will have access to
the store on the host. This is only implemented right now for `async |
store` functions which map to `CallStyle::Concurrent`. In the future
I'd like to support just-`store` functions which means that you could
define a synchronous function with access to the store in addition to
an asynchronous function.

* `trappable` - this means that the function returns a
`wasmtime::Result<TheWitBindingType>`. If `trappable_errors` is
applicable then it means just a `Result<TheWitOkType,
TrappableErrorType>` is returned (like before)

* `tracing` - this enables `tracing!` integration for this function.

* `verbose_tracing` - this logs all argument values for this function
(including lists).

* `ignore_wit` - this ignores the WIT-level defaults of the function
(e.g. ignoring WIT `async`).

The way this then works is all modeled is that for any WIT function
being generated there are a set of flags associated with that function.
To calculate the flags the algorithm looks like:

1. Find the first matching rule in the `imports` or `exports` map
depending on if the function is imported or exported. If there is no
matching rule then use the `default` rule if present. This is the
initial set of flags for the function (or empty if nothing was
found).

2. If `ignore_wit` is present, return the flags from step 1. Otherwise
add in `async | store` if the function is `async` in WIT.

The resulting set of flags are then used to control how everything is
generated. For example the same split traits of today are still
generated and it's controlled based on the flags. Note though that the
previous `HostConcurrent` trait was renamed to `HostWithStore` to make
space for synchronous functions in this trait in the future too.

The end result of all these changes is that configuring imports/exports
now uses the exact same selection system as the `with` replacement map,
meaning there's only one system of selecting functions instead of 3.
WIT-level `async` is now respected by default meaning that bindings work
by default without further need to configure anything (unless more
functionality is desired).

One final minor change made here as well is that auto-generated
`instantiate` methods are now always synchronous and an
`instantiate_async` method is unconditionally generated for async mode.
This means that bindings always generate both functions and it's up to
the embedder to choose the appropriate one.

Closes #11246
Closes #11247

* Update expanded test expectations

prtest:full

* Fix the min platform embedding example

* Fix doc tests

* Always generate `*WithStore` traits

This helps when using the `with` mapping since that can always assume
that `HostWithStore` is available in the generated bindings, avoiding
the need to duplicate configuration options.

* Update test expectations

* Review comments

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add Component Model async ABI tests (#11136)

* add Component Model async ABI tests

This pulls in the tests from the `wasip3-prototyping` repo, minus the ones
requiring WASIp3 support in `wasmtime-w

add Component Model async ABI tests (#11136)

* add Component Model async ABI tests

This pulls in the tests from the `wasip3-prototyping` repo, minus the ones
requiring WASIp3 support in `wasmtime-wasi[-http]`, which will be PR'd
separately.

* add audits and exemptions for new `component-async-tests` deps

In order to convince `cargo vet` that we only needed these deps to be
`safe-to-run` (not necessarily `safe-to-deploy`, since it's test code), I've
moved the `wasm-compose` dep to the `dev-dependencies` section of the
`Cargo.toml` file, which required rearranging some code.

I've exempted `wasm-compose` since it's a BA project, and also exempted all but
one of the remaining new deps since they each get well over 10,000 downloads per
day from crates.io. I've audited and certified the remaining dep, `im-rc`,
which came in a bit shy of the 10,000-per-day mark.

Signed-off-by: Joel Dice <[email protected]>

* simplify `component_async_tests::util::sleep`

Signed-off-by: Joel Dice <[email protected]>

---------

Signed-off-by: Joel Dice <[email protected]>

show more ...