cranelift

rust jit wasm webassembly runtime wasi cranelift sandbox wasmtime

Nick Fitzgerald ff93bce067 Wasmtime: Finish support for the typed function references proposal (#7943 ) * Wasmtime: Finish support for the typed function references proposal While we supported the function references proposal inside Wasm, we didn't support it on the "outside" in the Wasmtime embedder APIs. So much of the work here is exposing typed function references, and their type system updates, in the embedder API. These changes include: * `ValType::FuncRef` and `ValType::ExternRef` are gone, replaced with the introduction of the `RefType` and `HeapType` types and a `ValType::Ref(RefType)` variant. * `ValType` and `FuncType` no longer implement `Eq` and `PartialEq`. Instead there are `ValType::matches` and `FuncType::matches` methods which check directional subtyping. I also added `ValType::eq` and `FuncType::eq` static methods for the rare case where someone needs to check precise equality, but that is almost never actually the case, 99.99% of the time you want to check subtyping. * There are also public `Val::matches_ty` predicates for checking if a value is an instance of a type, as well as internal helpers like `Val::ensure_matches_ty` that return a formatted error if the value does not match the given type. These helpers are used throughout Wasmtime internals now. * There is now a dedicated `wasmtime::Ref` type that represents reference values. Table operations have been updated to take and return `Ref`s rather than `Val`s. Furthermore, this commit also includes type registry changes to correctly manage lifetimes of types that reference other types. This wasn't previously an issue because the only thing that could reference types that reference other types was a Wasm module that added all the types that could reference each other at the same time and removed them all at the same time. But now that the previously discussed work to expose these things in the embedder API is done, type lifetime management in the registry becomes a little trickier because the embedder might grab a reference to a type that references another type, and then unload the Wasm module that originally defined that type, but then the user should still be able use that type and the other types it transtively references. Before, we were refcounting individual registry entries. Now, we still are refcounting individual entries, but now we are also accounting for type-to-type references and adding a new type to the registry will increment the refcounts of each of the types that it references, and removing a type from the registry will decrement the refcounts of each of the types it references, and then recursively (logically, not literally) remove any types whose refcount has now reached zero. Additionally, this PR adds support for subtyping to `Func::typed`- and `Func::wrap`-style APIs. For result types, you can always use a supertype of the WebAssembly function's actual declared return type in `Func::typed`. And for param types, you can always use a subtype of the Wasm function's actual declared param type. Doing these things essentially erases information but is always correct. But additionally, for functions which take a reference to a concrete type as a parameter, you can also use the concrete type's supertype. Consider a WebAssembly function that takes a reference to a function with a concrete type: `(ref null <func type index>)`. In this scenario, there is no static `wasmtime::Foo` Rust type that corresponds to that particular Wasm-defined concrete reference type because Wasm modules are loaded dynamically at runtime. You could do `f.typed::<Option<NoFunc>, ()>()`, and while that is correctly typed and valid, it is often overly restrictive. The only value you could call the resulting typed function with is the null function reference, but we'd like to call it with non-null function references that happen to be of the correct type. Therefore, `f.typed<Option<Func>, ()>()` is also allowed in this case, even though `Option<Func>` represents `(ref null func)` which is the supertype, not subtype, of `(ref null <func type index>)`. This does imply some minimal dynamic type checks in this case, but it is supported for better ergonomics, to enable passing non-null references into the function. We can investigate whether it is possible to use generic type parameters and combinators to define Rust types that precisely match concrete reference types in future, follow-up pull requests. But for now, we've made things usable, at least. Finally, this also takes the first baby step towards adding support for the Wasm GC proposal. Right now the only thing that is supported is `nofunc` references, and this was mainly to make testing function reference subtyping easier. But that does mean that supporting `nofunc` references entailed also adding a `wasmtime::NoFunc` type as well as the `Config::wasm_gc(enabled)` knob. So we officially have an in-progress implementation of Wasm GC in Wasmtime after this PR lands! Fixes https://github.com/bytecodealliance/wasmtime/issues/6455 * Fix WAT in test to be valid * Check that dependent features are enabled for function-references and GC * Remove unnecessary engine parameters from a few methods Ever since `FuncType`'s internal `RegisteredType` holds onto its own `Engine`, we don't need these anymore. Still useful to keep the `Engine` parameter around for the `ensure_matches` methods because that can be used to check correct store/engine usage for embedders. * Add missing dependent feature enabling for some tests * Remove copy-paste bit from test * match self to show it is uninhabited * Add a missing `is_v128` method * Short circuit a few func type comparisons * Turn comment into part of doc comment * Add test for `Global::new` and subtyping * Add tests for embedder API, tables, and subtyping * Add an embedder API test for setting globals and subtyping * Construct realloc's type from its index, rather than from scratch * Help LLVM better optimize our dynamic type checks in `TypedFunc::call_raw` * Fix call benchmark compilation * Change `WasmParams::into_abi` to take the whole func type instead of iter of params * Fix doc links prtest:full * Fix size assertion on s390x		9 months ago
..
src	Wasmtime: Finish support for the typed function references proposal (#7943)	9 months ago
Cargo.toml	Decouple `serde` from its `derive` crate (#6917)	1 year ago
LICENSE	Add license file to wasmtime-types	3 years ago