wasmtime-internal-cranelift 47.0.2

INTERNAL: Integration between Cranelift and Wasmtime
Documentation 
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//! All the runtime support necessary for the wasm to cranelift translation is formalized by the
//! traits `FunctionEnvironment` and `ModuleEnvironment`.
//!
//! There are skeleton implementations of these traits in the `dummy` module, and complete
//! implementations in [Wasmtime].
//!
//! [Wasmtime]: https://github.com/bytecodealliance/wasmtime

use cranelift_codegen::ir;
use cranelift_codegen::isa::TargetFrontendConfig;
use smallvec::SmallVec;
use wasmtime_environ::{Tunables, TypeConvert, WasmHeapType};

/// Environment affecting the translation of a WebAssembly.
pub trait TargetEnvironment: TypeConvert {
    /// Get the information needed to produce Cranelift IR for the given target.
    fn target_config(&self) -> TargetFrontendConfig;

    /// Whether to enable Spectre mitigations for heap accesses.
    fn heap_access_spectre_mitigation(&self) -> bool;

    /// Get the Cranelift reference type to use for the given Wasm reference
    /// type.
    ///
    /// Returns a pair of the CLIF reference type to use and a boolean that
    /// describes whether the value should be included in GC stack maps or not.
    fn reference_type(&self, ty: WasmHeapType) -> (ir::Type, bool);

    /// Returns the compilation knobs that are in effect.
    fn tunables(&self) -> &Tunables;
}

/// A smallvec that holds the IR values for a struct's fields.
pub type StructFieldsVec = SmallVec<[ir::Value; 4]>;