Function vectorcall_function

crates/vm/src/builtins/function.rs:1386–1429

Vectorcall implementation for PyFunction (PEP 590). Takes owned args to avoid cloning when filling fastlocals.

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

/// Vectorcall implementation for PyFunction (PEP 590).
/// Takes owned args to avoid cloning when filling fastlocals.
pub(crate) fn vectorcall_function(
    zelf_obj: &PyObject,
    mut args: Vec<PyObjectRef>,
    nargs: usize,
    kwnames: Option<&[PyObjectRef]>,
    vm: &VirtualMachine,
) -> PyResult {
    let zelf: &Py<PyFunction> = zelf_obj.downcast_ref().unwrap();
    let code: &Py<PyCode> = &zelf.code;

    let has_kwargs = kwnames.is_some_and(|kw| !kw.is_empty());
    let is_simple = !has_kwargs
        && code.flags.contains(bytecode::CodeFlags::OPTIMIZED)
        && !code.flags.contains(bytecode::CodeFlags::VARARGS)
        && !code.flags.contains(bytecode::CodeFlags::VARKEYWORDS)
        && code.kwonlyarg_count == 0
        && !code
            .flags
            .intersects(bytecode::CodeFlags::GENERATOR | bytecode::CodeFlags::COROUTINE);

    if is_simple && nargs == code.arg_count as usize {
        // FAST PATH: simple positional-only call, exact arg count.
        // Move owned args directly into fastlocals — no clone needed.
        args.truncate(nargs);
        let frame = zelf.prepare_exact_args_frame(args, vm);

        let result = vm.run_frame(frame.clone());
        unsafe {
            if let Some(base) = frame.materialize_localsplus() {
                vm.datastack_pop(base);
            }
        }
        return result;
    }

    // SLOW PATH: construct FuncArgs from owned Vec and delegate to invoke()
    let func_args = if has_kwargs {
        FuncArgs::from_vectorcall(&args, nargs, kwnames)
    } else {
        args.truncate(nargs);
        FuncArgs::from(args)
    };
    zelf.invoke(func_args, vm)
}

/// Vectorcall implementation for PyBoundMethod (PEP 590).
fn vectorcall_bound_method(