Enum HostCall

pub enum HostCall {
    ArrayCall,
    Builtin(BuiltinFunctionIndex),
    ComponentLowerImport,
    ComponentBuiltin(ComponentBuiltinFunctionIndex),
}

Enumeration of all possible ways that wasm may execute code in the host.

This type is intended to be serialized into a 32-bit index (or smaller) and is used by Pulley for example to identify how transitions from the guest to the host are performed.

Variants

ArrayCall

An “array call” is being done which means that the wasm is calling the host using the array calling convention (e.g. VMArrayCallNative).

Builtin(BuiltinFunctionIndex)

A builtin function, e.g. for memory.grow, is being called. Each builtin has its own ABI.

ComponentLowerImport

A lowered component function is being called. This is done by a trampoline generated by Cranelift and is distinct from the array calling convention.

This correspond to VMLoweringCallee.

ComponentBuiltin(ComponentBuiltinFunctionIndex)

A builtin function, but specifically for components. For example string transcoders.

Implementations

impl HostCall

pub const fn index(&self) -> u32

Returns a 32-bit index for this hostcall.

Trait Implementations

impl From<BuiltinFunctionIndex> for HostCall

fn from(idx: BuiltinFunctionIndex) -> HostCall

Converts to this type from the input type.

impl From<ComponentBuiltinFunctionIndex> for HostCall

fn from(idx: ComponentBuiltinFunctionIndex) -> HostCall

Converts to this type from the input type.