micropython/py/objboundmeth.c

#include <string.h>

#include "mpconfig.h"
#include "nlr.h"
#include "misc.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"

typedef struct _mp_obj_bound_meth_t {
    mp_obj_base_t base;
    mp_obj_t meth;
    mp_obj_t self;
} mp_obj_bound_meth_t;

mp_obj_t bound_meth_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
    mp_obj_bound_meth_t *self = self_in;

    // need to insert self->self before all other args and then call self->meth

    int n_total = n_args + 2 * n_kw;
    if (n_total <= 4) {
        // use stack to allocate temporary args array
        mp_obj_t args2[5];
        args2[0] = self->self;
        memcpy(args2 + 1, args, n_total * sizeof(mp_obj_t));
        return mp_call_function_n_kw(self->meth, n_args + 1, n_kw, &args2[0]);
    } else {
        // use heap to allocate temporary args array
        mp_obj_t *args2 = m_new(mp_obj_t, 1 + n_total);
        args2[0] = self->self;
        memcpy(args2 + 1, args, n_total * sizeof(mp_obj_t));
        mp_obj_t res = mp_call_function_n_kw(self->meth, n_args + 1, n_kw, &args2[0]);
        m_del(mp_obj_t, args2, 1 + n_total);
        return res;
    }
}

const mp_obj_type_t bound_meth_type = {
    { &mp_type_type },
    .name = MP_QSTR_bound_method,
    .call = bound_meth_call,
};

mp_obj_t mp_obj_new_bound_meth(mp_obj_t meth, mp_obj_t self) {
    mp_obj_bound_meth_t *o = m_new_obj(mp_obj_bound_meth_t);
    o->base.type = &bound_meth_type;
    o->meth = meth;
    o->self = self;
    return o;
}