Function vectorcall_native_function

crates/vm/src/builtins/builtin_func.rs:231–257

Vectorcall for builtin functions (PEP 590). Avoids `prepend_arg` O(n) shift by building args with self at front.

(
    zelf_obj: &PyObject,
    args: Vec<PyObjectRef>,
    nargs: usize,
    kwnames: Option<&[PyObjectRef]>,
    vm: &VirtualMachine,
)

/// Vectorcall for builtin functions (PEP 590).
/// Avoids `prepend_arg` O(n) shift by building args with self at front.
fn vectorcall_native_function(
    zelf_obj: &PyObject,
    args: Vec<PyObjectRef>,
    nargs: usize,
    kwnames: Option<&[PyObjectRef]>,
    vm: &VirtualMachine,
) -> PyResult {
    let zelf: &Py<PyNativeFunction> = zelf_obj.downcast_ref().unwrap();

    // Build FuncArgs with self already at position 0 (no insert(0) needed)
    let needs_self = zelf
        .zelf
        .as_ref()
        .is_some_and(|_| !zelf.value.flags.contains(PyMethodFlags::STATIC));

    let func_args = if needs_self {
        let self_obj = zelf.zelf.as_ref().unwrap().clone();
        let mut all_args = Vec::with_capacity(args.len() + 1);
        all_args.push(self_obj);
        all_args.extend(args);
        FuncArgs::from_vectorcall(&all_args, nargs + 1, kwnames)
    } else {
        FuncArgs::from_vectorcall(&args, nargs, kwnames)
    };

    (zelf.value.func)(vm, func_args)
}

pub fn init(context: &'static Context) {
    PyNativeFunction::extend_class(context, context.types.builtin_function_or_method_type);