Function make_native_binding

compiler/src/main/abi_bridge.rs:342–377

Builds a NativeBinding that marshals handles around `host_call_native`. Kept out of resolver.rs so the resolver stays ABI-agnostic. */

(name: String, id: u32)

/* Builds a NativeBinding that marshals handles around `host_call_native`. Kept out of resolver.rs so the resolver stays ABI-agnostic. */
pub(super) fn make_native_binding(name: String, id: u32) -> NativeBinding {
    let closure = move |_: &mut crate::modules::vm::types::HeapPool, args: &[Val], kwargs: Option<Val>| -> Result<Val, VmErr> {
        /* 1. Register positional args as handles the guest will see; append the kwargs handle (0 means no kwargs). */
        let mut argv: Vec<u32> = args.iter().map(|v| put_val(*v)).collect();
        argv.push(kwargs.map_or(0, put_val));
        let mut out_handle: u32 = 0;

        // call_id is what call_extern will park with on defer; lets the host route the result back.
        let call_id = with_vm(|vm| vm.next_host_call_id as u32).unwrap_or(0);
        let status = unsafe {
            host_call_native(
                id, call_id,
                argv.as_ptr(), argv.len() as u32,
                &mut out_handle as *mut u32,
            )
        };

        /* 3. Read result BEFORE releasing argv: a returned input would point into slots we're about to free. */
        // Status 2 = DEFERRED: handler has captured what it needs; release argv and park the VM.
        if status == 2 {
            release_handles(&argv);
            return Err(VmErr::HostCallDeferred);
        }
        if status != 0 {
            release_handles(&argv);
            let (kind, msg) = with_runtime(|rt| rt.error_stash.take())
                .unwrap_or((ErrorKind::Runtime as u32, String::from("native call failed")));
            return Err(error_from_kind(kind, msg));
        }
        let result = get_val(out_handle).ok_or(VmErr::Runtime("native returned invalid handle"))?;
        argv.push(out_handle);
        release_handles(&argv);
        Ok(result)
    };
    NativeBinding { name, func: Arc::new(closure), pure: false }
}