ddfadaeb38
* Remove unnecessary into_iter/map Forgotten from a previous refactoring, this variable was already of the right type! * Move `wasmtime_jit::Compiler` into `wasmtime` This `Compiler` struct is mostly a historical artifact at this point and wasn't necessarily pulling much weight any more. This organization also doesn't lend itself super well to compiling out `cranelift` when the `Compiler` here is used for both parallel iteration configuration settings as well as compilation. The movement into `wasmtime` is relatively small, with `Module::build_artifacts` being the main function added here which is a merging of the previous functions removed from the `wasmtime-jit` crate. * Add a `cranelift` compile-time feature to `wasmtime` This commit concludes the saga of refactoring Wasmtime and making Cranelift an optional dependency by adding a new Cargo feature to the `wasmtime` crate called `cranelift`, which is enabled by default. This feature is implemented by having a new cfg for `wasmtime` itself, `cfg(compiler)`, which is used wherever compilation is necessary. This bubbles up to disable APIs such as `Module::new`, `Func::new`, `Engine::precompile_module`, and a number of `Config` methods affecting compiler configuration. Checks are added to CI that when built in this mode Wasmtime continues to successfully build. It's hoped that although this is effectively "sprinkle `#[cfg]` until things compile" this won't be too too bad to maintain over time since it's also an use case we're interested in supporting. With `cranelift` disabled the only way to create a `Module` is with the `Module::deserialize` method, which requires some form of precompiled artifact. Two consequences of this change are: * `Module::serialize` is also disabled in this mode. The reason for this is that serialized modules contain ISA/shared flags encoded in them which were used to produce the compiled code. There's no storage for this if compilation is disabled. This could probably be re-enabled in the future if necessary, but it may not end up being all that necessary. * Deserialized modules are not checked to ensure that their ISA/shared flags are compatible with the host CPU. This is actually already the case, though, with normal modules. We'll likely want to fix this in the future using a shared implementation for both these locations. Documentation should be updated to indicate that `cranelift` can be disabled, although it's not really the most prominent documentation because this is expected to be a somewhat niche use case (albeit important, just not too common). * Always enable cranelift for the C API * Fix doc example builds * Fix check tests on GitHub Actions
21 lines
994 B
Rust
21 lines
994 B
Rust
fn main() {
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// Code in the `wasmtime` crate will use #[cfg(compiler)] conditional
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// compilation when runtime compilation is supported or not. This #[cfg] is
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// defined by this build script here, and is guarded with a conditional.
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// Currently this conditional is #[cfg(feature = "cranelift")] since that's
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// the only supported compiler.
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//
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// Note that #[doc(cfg)] throughout the `wasmtime` crate points here. We
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// want the rustdoc documentation to accurately reflect the requirements for
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// APIs, so the condition here is duplicated into all #[doc(cfg)]
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// attributes. If this condition is updated to emit #[cfg(compiler)] more
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// frequently then all rustdoc attributes also need to be updated with the
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// new condition to ensure the documentation accurately reflects when an API
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// is available.
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if cfg!(feature = "cranelift") {
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println!("cargo:rustc-cfg=compiler");
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}
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println!("cargo:rerun-if-changed=build.rs");
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}
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