add circuitpython code

1 files changed, 1541 insertions, 0 deletions

diff --git a/circuitpython/py/objtype.c b/circuitpython/py/objtype.c
new file mode 100644
index 0000000..62ea1ed
--- /dev/null
+++ b/circuitpython/py/objtype.c
@@ -0,0 +1,1541 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2013-2018 Damien P. George
+ * SPDX-FileCopyrightText: Copyright (c) 2014-2018 Paul Sokolovsky
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+#include <assert.h>
+
+#include "py/gc_long_lived.h"
+#include "py/objtype.h"
+#include "py/runtime.h"
+
+#include "supervisor/shared/stack.h"
+#include "supervisor/shared/translate.h"
+
+#if MICROPY_DEBUG_VERBOSE // print debugging info
+#define DEBUG_PRINT (1)
+#define DEBUG_printf DEBUG_printf
+#else // don't print debugging info
+#define DEBUG_PRINT (0)
+#define DEBUG_printf(...) (void)0
+#endif
+
+#define ENABLE_SPECIAL_ACCESSORS \
+    (MICROPY_PY_DESCRIPTORS || MICROPY_PY_DELATTR_SETATTR || MICROPY_PY_BUILTINS_PROPERTY)
+
+STATIC mp_obj_t static_class_method_make_new(const mp_obj_type_t *self, size_t n_args, size_t n_kw, const mp_obj_t *args);
+
+/******************************************************************************/
+// instance object
+
+STATIC int instance_count_native_bases(const mp_obj_type_t *type, const mp_obj_type_t **last_native_base) {
+    int count = 0;
+    for (;;) {
+        if (type == &mp_type_object) {
+            // Not a "real" type, end search here.
+            return count;
+        }
+        if (mp_obj_is_native_type(type)) {
+            // Native types don't have parents (at least not from our perspective) so end.
+            *last_native_base = type;
+            return count + 1;
+        }
+        const void *parent = mp_type_get_parent_slot(type);
+        if (parent == NULL) {
+            // No parents so end search here.
+            return count;
+        #if MICROPY_MULTIPLE_INHERITANCE
+        } else if (((mp_obj_base_t *)parent)->type == &mp_type_tuple) {
+            // Multiple parents, search through them all recursively.
+            const mp_obj_tuple_t *parent_tuple = parent;
+            const mp_obj_t *item = parent_tuple->items;
+            const mp_obj_t *top = item + parent_tuple->len;
+            for (; item < top; ++item) {
+                assert(mp_obj_is_type(*item, &mp_type_type));
+                const mp_obj_type_t *bt = (const mp_obj_type_t *)MP_OBJ_TO_PTR(*item);
+                count += instance_count_native_bases(bt, last_native_base);
+            }
+            return count;
+        #endif
+        } else {
+            // A single parent, use iteration to continue the search.
+            type = parent;
+        }
+    }
+}
+
+// This wrapper function is allows a subclass of a native type to call the
+// __init__() method (corresponding to type->make_new) of the native type.
+STATIC mp_obj_t native_base_init_wrapper(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(pos_args[0]);
+    const mp_obj_type_t *native_base = NULL;
+    instance_count_native_bases(self->base.type, &native_base);
+
+    size_t n_kw = kw_args ? kw_args->used : 0;
+
+    // consume the type object
+    pos_args++;
+    n_args--;
+
+    mp_obj_t *args2 = m_new(mp_obj_t, n_args + 2 * n_kw);
+    // copy in args
+    memcpy(args2, pos_args, n_args * sizeof(mp_obj_t));
+    // copy in kwargs
+    memcpy(args2 + n_args, kw_args->table, 2 * n_kw * sizeof(mp_obj_t));
+    self->subobj[0] = native_base->make_new(native_base, n_args, n_kw, args2);
+    m_del(mp_obj_t, args2, n_args + 2 * n_kw);
+
+    return mp_const_none;
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_KW(native_base_init_wrapper_obj, 1, native_base_init_wrapper);
+
+#if !MICROPY_CPYTHON_COMPAT
+STATIC
+#endif
+mp_obj_instance_t *mp_obj_new_instance(const mp_obj_type_t *class, const mp_obj_type_t **native_base) {
+    size_t num_native_bases = instance_count_native_bases(class, native_base);
+    assert(num_native_bases < 2);
+    mp_obj_instance_t *o = m_new_obj_var(mp_obj_instance_t, mp_obj_t, num_native_bases);
+    o->base.type = class;
+    mp_map_init(&o->members, 0);
+    // Initialise the native base-class slot (should be 1 at most) with a valid
+    // object.  It doesn't matter which object, so long as it can be uniquely
+    // distinguished from a native class that is initialised.
+    if (num_native_bases != 0) {
+        o->subobj[0] = MP_OBJ_FROM_PTR(&native_base_init_wrapper_obj);
+    }
+    return o;
+}
+
+// When instances are first created they have the base_init wrapper as their native parent's
+// instance because make_new combines __new__ and __init__. This object is invalid for the native
+// code so it must call this method to ensure that the given object has been __init__'d and is
+// valid.
+void mp_obj_assert_native_inited(mp_obj_t native_object) {
+    if (native_object == MP_OBJ_FROM_PTR(&native_base_init_wrapper_obj)) {
+        mp_raise_NotImplementedError(MP_ERROR_TEXT("Call super().__init__() before accessing native object."));
+    }
+}
+
+// TODO
+// This implements depth-first left-to-right MRO, which is not compliant with Python3 MRO
+// http://python-history.blogspot.com/2010/06/method-resolution-order.html
+// https://www.python.org/download/releases/2.3/mro/
+//
+// will keep lookup->dest[0]'s value (should be MP_OBJ_NULL on invocation) if attribute
+// is not found
+// will set lookup->dest[0] to MP_OBJ_SENTINEL if special method was found in a native
+// type base via slot id (as specified by lookup->meth_offset). As there can be only one
+// native base, it's known that it applies to instance->subobj[0]. In most cases, we also
+// don't need to know which type it was - because instance->subobj[0] is of that type.
+// The only exception is when object is not yet constructed, then we need to know base
+// native type to construct its instance->subobj[0] from. But this case is handled via
+// instance_count_native_bases(), which returns a native base which it saw.
+struct class_lookup_data {
+    mp_obj_instance_t *obj;
+    qstr attr;
+    size_t meth_offset;
+    mp_obj_t *dest;
+    bool is_type;
+};
+
+STATIC void mp_obj_class_lookup(struct class_lookup_data *lookup, const mp_obj_type_t *type) {
+    assert(lookup->dest[0] == MP_OBJ_NULL);
+    assert(lookup->dest[1] == MP_OBJ_NULL);
+    for (;;) {
+        DEBUG_printf("mp_obj_class_lookup: Looking up %s in %s\n", qstr_str(lookup->attr), qstr_str(type->name));
+        // Optimize special method lookup for native types
+        // This avoids extra method_name => slot lookup. On the other hand,
+        // this should not be applied to class types, as will result in extra
+        // lookup either.
+        if (lookup->meth_offset != 0 && mp_obj_is_native_type(type)) {
+            #pragma GCC diagnostic push
+            #pragma GCC diagnostic ignored "-Wcast-align"
+            size_t sz = mp_type_size(type);
+            if (lookup->meth_offset < sz && *(void **)((char *)type + lookup->meth_offset) != NULL) {
+                #pragma GCC diagnostic pop
+                DEBUG_printf("mp_obj_class_lookup: Matched special meth slot (off=%d) for %s\n",
+                    lookup->meth_offset, qstr_str(lookup->attr));
+                lookup->dest[0] = MP_OBJ_SENTINEL;
+                return;
+            }
+        }
+
+        if (type->locals_dict != NULL) {
+            // search locals_dict (the set of methods/attributes)
+            assert(mp_obj_is_dict_or_ordereddict(MP_OBJ_FROM_PTR(type->locals_dict))); // MicroPython restriction, for now
+            mp_map_t *locals_map = &type->locals_dict->map;
+            mp_map_elem_t *elem = mp_map_lookup(locals_map, MP_OBJ_NEW_QSTR(lookup->attr), MP_MAP_LOOKUP);
+            if (elem != NULL) {
+                if (lookup->is_type) {
+                    // If we look up a class method, we need to return original type for which we
+                    // do a lookup, not a (base) type in which we found the class method.
+                    const mp_obj_type_t *org_type = (const mp_obj_type_t *)lookup->obj;
+                    mp_convert_member_lookup(MP_OBJ_NULL, org_type, elem->value, lookup->dest);
+                } else if (mp_obj_is_type(elem->value, &mp_type_property)) {
+                    lookup->dest[0] = elem->value;
+                    return;
+                } else {
+                    mp_obj_instance_t *obj = lookup->obj;
+                    mp_convert_member_lookup(MP_OBJ_FROM_PTR(obj), type, elem->value, lookup->dest);
+                }
+                #if DEBUG_PRINT
+                DEBUG_printf("mp_obj_class_lookup: Returning: ");
+                mp_obj_print_helper(MICROPY_DEBUG_PRINTER, lookup->dest[0], PRINT_REPR);
+                if (lookup->dest[1] != MP_OBJ_NULL) {
+                    // Don't try to repr() lookup->dest[1], as we can be called recursively
+                    DEBUG_printf(" <%s @%p>", mp_obj_get_type_str(lookup->dest[1]), MP_OBJ_TO_PTR(lookup->dest[1]));
+                }
+                DEBUG_printf("\n");
+                #endif
+                return;
+            }
+        }
+
+        // Previous code block takes care about attributes defined in .locals_dict,
+        // but some attributes of native types may be handled using .load_attr method,
+        // so make sure we try to lookup those too.
+        if (lookup->obj != NULL && !lookup->is_type && mp_obj_is_native_type(type) && type != &mp_type_object /* object is not a real type */) {
+            mp_load_method_maybe(lookup->obj->subobj[0], lookup->attr, lookup->dest);
+            if (lookup->dest[0] != MP_OBJ_NULL) {
+                return;
+            }
+        }
+
+        // attribute not found, keep searching base classes
+
+        const void *parent = mp_type_get_parent_slot(type);
+        if (parent == NULL) {
+            DEBUG_printf("mp_obj_class_lookup: No more parents\n");
+            return;
+        }
+        #if MICROPY_MULTIPLE_INHERITANCE
+        if (((mp_obj_base_t *)parent)->type == &mp_type_tuple) {
+            const mp_obj_tuple_t *parent_tuple = parent;
+            const mp_obj_t *item = parent_tuple->items;
+            const mp_obj_t *top = item + parent_tuple->len - 1;
+            for (; item < top; ++item) {
+                assert(mp_obj_is_type(*item, &mp_type_type));
+                mp_obj_type_t *bt = (mp_obj_type_t *)MP_OBJ_TO_PTR(*item);
+                if (bt == &mp_type_object) {
+                    // Not a "real" type
+                    continue;
+                }
+                mp_obj_class_lookup(lookup, bt);
+                if (lookup->dest[0] != MP_OBJ_NULL) {
+                    return;
+                }
+            }
+
+            // search last base (simple tail recursion elimination)
+            assert(mp_obj_is_type(*item, &mp_type_type));
+            type = (mp_obj_type_t *)MP_OBJ_TO_PTR(*item);
+            continue;
+        }
+        #endif
+        type = parent;
+        if (type == &mp_type_object) {
+            // Not a "real" type
+            return;
+        }
+    }
+}
+
+STATIC void instance_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+    qstr meth = (kind == PRINT_STR) ? MP_QSTR___str__ : MP_QSTR___repr__;
+    mp_obj_t member[2] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = meth,
+        .meth_offset = offsetof(mp_obj_type_t, print),
+        .dest = member,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+    if (member[0] == MP_OBJ_NULL && kind == PRINT_STR) {
+        // If there's no __str__, fall back to __repr__
+        lookup.attr = MP_QSTR___repr__;
+        lookup.meth_offset = 0;
+        mp_obj_class_lookup(&lookup, self->base.type);
+    }
+
+    if (member[0] == MP_OBJ_SENTINEL) {
+        // Handle Exception subclasses specially
+        if (mp_obj_is_native_exception_instance(self->subobj[0])) {
+            if (kind != PRINT_STR) {
+                mp_print_str(print, qstr_str(self->base.type->name));
+            }
+            mp_obj_print_helper(print, self->subobj[0], kind | PRINT_EXC_SUBCLASS);
+        } else {
+            mp_obj_print_helper(print, self->subobj[0], kind);
+        }
+        return;
+    }
+
+    if (member[0] != MP_OBJ_NULL) {
+        mp_obj_t r = mp_call_function_1(member[0], self_in);
+        mp_obj_print_helper(print, r, PRINT_STR);
+        return;
+    }
+
+    // TODO: CPython prints fully-qualified type name
+    mp_printf(print, "<%q object at %p>", mp_obj_get_type_qstr(self_in), self);
+}
+
+mp_obj_t mp_obj_instance_make_new(const mp_obj_type_t *self, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    assert(mp_obj_is_instance_type(self));
+
+    // look for __new__ function
+    mp_obj_t init_fn[2] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = NULL,
+        .attr = MP_QSTR___new__,
+        .meth_offset = offsetof(mp_obj_type_t, make_new),
+        .dest = init_fn,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self);
+
+    const mp_obj_type_t *native_base = NULL;
+    mp_obj_instance_t *o;
+    if (init_fn[0] == MP_OBJ_NULL || init_fn[0] == MP_OBJ_SENTINEL) {
+        // Either there is no __new__() method defined or there is a native
+        // constructor.  In both cases create a blank instance.
+        o = mp_obj_new_instance(self, &native_base);
+
+        // Since type->make_new() implements both __new__() and __init__() in
+        // one go, of which the latter may be overridden by the Python subclass,
+        // we defer (see the end of this function) the call of the native
+        // constructor to give a chance for the Python __init__() method to call
+        // said native constructor.
+
+    } else {
+        // Call Python class __new__ function with all args to create an instance
+        mp_obj_t new_ret;
+        if (n_args == 0 && n_kw == 0) {
+            mp_obj_t args2[1] = {MP_OBJ_FROM_PTR(self)};
+            new_ret = mp_call_function_n_kw(init_fn[0], 1, 0, args2);
+        } else {
+            // TODO(tannewt): Could this be on the stack? It's deleted below.
+            mp_obj_t *args2 = m_new(mp_obj_t, 1 + n_args + 2 * n_kw);
+            args2[0] = MP_OBJ_FROM_PTR(self);
+            memcpy(args2 + 1, args, (n_args + 2 * n_kw) * sizeof(mp_obj_t));
+            new_ret = mp_call_function_n_kw(init_fn[0], n_args + 1, n_kw, args2);
+            m_del(mp_obj_t, args2, 1 + n_args + 2 * n_kw);
+        }
+
+        // https://docs.python.org/3.4/reference/datamodel.html#object.__new__
+        // "If __new__() does not return an instance of cls, then the new
+        // instance's __init__() method will not be invoked."
+        if (mp_obj_get_type(new_ret) != self) {
+            return new_ret;
+        }
+
+        // The instance returned by __new__() becomes the new object
+        o = MP_OBJ_TO_PTR(new_ret);
+    }
+
+    // now call Python class __init__ function with all args
+    // This method has a chance to call super().__init__() to construct a
+    // possible native base class.
+    init_fn[0] = init_fn[1] = MP_OBJ_NULL;
+    lookup.obj = o;
+    lookup.attr = MP_QSTR___init__;
+    lookup.meth_offset = 0;
+    mp_obj_class_lookup(&lookup, self);
+    if (init_fn[0] != MP_OBJ_NULL) {
+        mp_obj_t init_ret;
+        if (n_args == 0 && n_kw == 0) {
+            init_ret = mp_call_method_n_kw(0, 0, init_fn);
+        } else {
+            // TODO(tannewt): Could this be on the stack? It's deleted below.
+            mp_obj_t *args2 = m_new(mp_obj_t, 2 + n_args + 2 * n_kw);
+            args2[0] = init_fn[0];
+            args2[1] = init_fn[1];
+            // copy in kwargs
+            memcpy(args2 + 2, args, (n_args + 2 * n_kw) * sizeof(mp_obj_t));
+            init_ret = mp_call_method_n_kw(n_args, n_kw, args2);
+            m_del(mp_obj_t, args2, 2 + n_args + 2 * n_kw);
+        }
+        if (init_ret != mp_const_none) {
+            #if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_TERSE
+            mp_raise_TypeError(MP_ERROR_TEXT("__init__() should return None"));
+            #else
+            mp_raise_TypeError_varg(MP_ERROR_TEXT("__init__() should return None, not '%q'"),
+                mp_obj_get_type_qstr(init_ret));
+            #endif
+        }
+    }
+
+    // If the type had a native base that was not explicitly initialised
+    // (constructed) by the Python __init__() method then construct it now.
+    if (native_base != NULL && o->subobj[0] == MP_OBJ_FROM_PTR(&native_base_init_wrapper_obj)) {
+        o->subobj[0] = native_base->make_new(native_base, n_args, n_kw, args);
+    }
+
+    return MP_OBJ_FROM_PTR(o);
+}
+
+// Qstrs for special methods are guaranteed to have a small value, so we use byte
+// type to represent them.
+const byte mp_unary_op_method_name[MP_UNARY_OP_NUM_RUNTIME] = {
+    [MP_UNARY_OP_BOOL] = MP_QSTR___bool__,
+    [MP_UNARY_OP_LEN] = MP_QSTR___len__,
+    [MP_UNARY_OP_HASH] = MP_QSTR___hash__,
+    [MP_UNARY_OP_INT] = MP_QSTR___int__,
+    #if MICROPY_PY_ALL_SPECIAL_METHODS
+    [MP_UNARY_OP_POSITIVE] = MP_QSTR___pos__,
+    [MP_UNARY_OP_NEGATIVE] = MP_QSTR___neg__,
+    [MP_UNARY_OP_INVERT] = MP_QSTR___invert__,
+    [MP_UNARY_OP_ABS] = MP_QSTR___abs__,
+    #endif
+    #if MICROPY_PY_SYS_GETSIZEOF
+    [MP_UNARY_OP_SIZEOF] = MP_QSTR___sizeof__,
+    #endif
+};
+
+STATIC mp_obj_t instance_unary_op(mp_unary_op_t op, mp_obj_t self_in) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+
+    #if MICROPY_PY_SYS_GETSIZEOF
+    if (MP_UNLIKELY(op == MP_UNARY_OP_SIZEOF)) {
+        // TODO: This doesn't count inherited objects (self->subobj)
+        const mp_obj_type_t *native_base;
+        size_t num_native_bases = instance_count_native_bases(mp_obj_get_type(self_in), &native_base);
+
+        size_t sz = sizeof(*self) + sizeof(*self->subobj) * num_native_bases
+            + sizeof(*self->members.table) * self->members.alloc;
+        return MP_OBJ_NEW_SMALL_INT(sz);
+    }
+    #endif
+
+    qstr op_name = mp_unary_op_method_name[op];
+    /* Still try to lookup native slot
+    if (op_name == 0) {
+        return MP_OBJ_NULL;
+    }
+    */
+    mp_obj_t member[2] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = op_name,
+        .meth_offset = offsetof(mp_obj_type_t, ext[0].unary_op),
+        .dest = member,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+    if (member[0] == MP_OBJ_SENTINEL) {
+        return mp_unary_op(op, self->subobj[0]);
+    } else if (member[0] != MP_OBJ_NULL) {
+        mp_obj_t val = mp_call_function_1(member[0], self_in);
+
+        switch (op) {
+            case MP_UNARY_OP_HASH:
+                // __hash__ must return a small int
+                val = MP_OBJ_NEW_SMALL_INT(mp_obj_get_int_truncated(val));
+                break;
+            case MP_UNARY_OP_INT:
+                // Must return int
+                if (!mp_obj_is_int(val)) {
+                    mp_raise_TypeError(NULL);
+                }
+                break;
+            default:
+                // No need to do anything
+                ;
+        }
+        return val;
+    } else {
+        if (op == MP_UNARY_OP_HASH) {
+            lookup.attr = MP_QSTR___eq__;
+            mp_obj_class_lookup(&lookup, self->base.type);
+            if (member[0] == MP_OBJ_NULL) {
+                // https://docs.python.org/3/reference/datamodel.html#object.__hash__
+                // "User-defined classes have __eq__() and __hash__() methods by default;
+                // with them, all objects compare unequal (except with themselves) and
+                // x.__hash__() returns an appropriate value such that x == y implies
+                // both that x is y and hash(x) == hash(y)."
+                return MP_OBJ_NEW_SMALL_INT((mp_uint_t)self_in);
+            }
+            // "A class that overrides __eq__() and does not define __hash__() will have its __hash__() implicitly set to None.
+            // When the __hash__() method of a class is None, instances of the class will raise an appropriate TypeError"
+        }
+
+        return MP_OBJ_NULL; // op not supported
+    }
+}
+
+// Binary-op enum values not listed here will have the default value of 0 in the
+// table, corresponding to MP_QSTRnull, and are therefore unsupported (a lookup will
+// fail).  They can be added at the expense of code size for the qstr.
+// Qstrs for special methods are guaranteed to have a small value, so we use byte
+// type to represent them.
+const byte mp_binary_op_method_name[MP_BINARY_OP_NUM_RUNTIME] = {
+    [MP_BINARY_OP_LESS] = MP_QSTR___lt__,
+    [MP_BINARY_OP_MORE] = MP_QSTR___gt__,
+    [MP_BINARY_OP_EQUAL] = MP_QSTR___eq__,
+    [MP_BINARY_OP_LESS_EQUAL] = MP_QSTR___le__,
+    [MP_BINARY_OP_MORE_EQUAL] = MP_QSTR___ge__,
+    [MP_BINARY_OP_NOT_EQUAL] = MP_QSTR___ne__,
+    [MP_BINARY_OP_CONTAINS] = MP_QSTR___contains__,
+
+    // If an inplace method is not found a normal method will be used as a fallback
+    [MP_BINARY_OP_INPLACE_ADD] = MP_QSTR___iadd__,
+    [MP_BINARY_OP_INPLACE_SUBTRACT] = MP_QSTR___isub__,
+    #if MICROPY_PY_ALL_INPLACE_SPECIAL_METHODS
+    [MP_BINARY_OP_INPLACE_MULTIPLY] = MP_QSTR___imul__,
+    [MP_BINARY_OP_INPLACE_MAT_MULTIPLY] = MP_QSTR___imatmul__,
+    [MP_BINARY_OP_INPLACE_FLOOR_DIVIDE] = MP_QSTR___ifloordiv__,
+    [MP_BINARY_OP_INPLACE_TRUE_DIVIDE] = MP_QSTR___itruediv__,
+    [MP_BINARY_OP_INPLACE_MODULO] = MP_QSTR___imod__,
+    [MP_BINARY_OP_INPLACE_POWER] = MP_QSTR___ipow__,
+    [MP_BINARY_OP_INPLACE_OR] = MP_QSTR___ior__,
+    [MP_BINARY_OP_INPLACE_XOR] = MP_QSTR___ixor__,
+    [MP_BINARY_OP_INPLACE_AND] = MP_QSTR___iand__,
+    [MP_BINARY_OP_INPLACE_LSHIFT] = MP_QSTR___ilshift__,
+    [MP_BINARY_OP_INPLACE_RSHIFT] = MP_QSTR___irshift__,
+    #endif
+
+    [MP_BINARY_OP_ADD] = MP_QSTR___add__,
+    [MP_BINARY_OP_SUBTRACT] = MP_QSTR___sub__,
+    #if MICROPY_PY_ALL_SPECIAL_METHODS
+    [MP_BINARY_OP_MULTIPLY] = MP_QSTR___mul__,
+    [MP_BINARY_OP_MAT_MULTIPLY] = MP_QSTR___matmul__,
+    [MP_BINARY_OP_FLOOR_DIVIDE] = MP_QSTR___floordiv__,
+    [MP_BINARY_OP_TRUE_DIVIDE] = MP_QSTR___truediv__,
+    [MP_BINARY_OP_MODULO] = MP_QSTR___mod__,
+    [MP_BINARY_OP_DIVMOD] = MP_QSTR___divmod__,
+    [MP_BINARY_OP_POWER] = MP_QSTR___pow__,
+    [MP_BINARY_OP_OR] = MP_QSTR___or__,
+    [MP_BINARY_OP_XOR] = MP_QSTR___xor__,
+    [MP_BINARY_OP_AND] = MP_QSTR___and__,
+    [MP_BINARY_OP_LSHIFT] = MP_QSTR___lshift__,
+    [MP_BINARY_OP_RSHIFT] = MP_QSTR___rshift__,
+    #endif
+
+    #if MICROPY_PY_REVERSE_SPECIAL_METHODS
+    [MP_BINARY_OP_REVERSE_ADD] = MP_QSTR___radd__,
+    [MP_BINARY_OP_REVERSE_SUBTRACT] = MP_QSTR___rsub__,
+    #if MICROPY_PY_ALL_SPECIAL_METHODS
+    [MP_BINARY_OP_REVERSE_MULTIPLY] = MP_QSTR___rmul__,
+    [MP_BINARY_OP_REVERSE_MAT_MULTIPLY] = MP_QSTR___rmatmul__,
+    [MP_BINARY_OP_REVERSE_FLOOR_DIVIDE] = MP_QSTR___rfloordiv__,
+    [MP_BINARY_OP_REVERSE_TRUE_DIVIDE] = MP_QSTR___rtruediv__,
+    [MP_BINARY_OP_REVERSE_MODULO] = MP_QSTR___rmod__,
+    [MP_BINARY_OP_REVERSE_POWER] = MP_QSTR___rpow__,
+    [MP_BINARY_OP_REVERSE_OR] = MP_QSTR___ror__,
+    [MP_BINARY_OP_REVERSE_XOR] = MP_QSTR___rxor__,
+    [MP_BINARY_OP_REVERSE_AND] = MP_QSTR___rand__,
+    [MP_BINARY_OP_REVERSE_LSHIFT] = MP_QSTR___rlshift__,
+    [MP_BINARY_OP_REVERSE_RSHIFT] = MP_QSTR___rrshift__,
+    #endif
+    #endif
+};
+
+STATIC mp_obj_t instance_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
+    // Note: For ducktyping, CPython does not look in the instance members or use
+    // __getattr__ or __getattribute__.  It only looks in the class dictionary.
+    mp_obj_instance_t *lhs = MP_OBJ_TO_PTR(lhs_in);
+retry:;
+    qstr op_name = mp_binary_op_method_name[op];
+    /* Still try to lookup native slot
+    if (op_name == 0) {
+        return MP_OBJ_NULL;
+    }
+    */
+    mp_obj_t dest[3] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = lhs,
+        .attr = op_name,
+        .meth_offset = offsetof(mp_obj_type_t, ext[0].binary_op),
+        .dest = dest,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, lhs->base.type);
+
+    mp_obj_t res;
+    if (dest[0] == MP_OBJ_SENTINEL) {
+        res = mp_binary_op(op, lhs->subobj[0], rhs_in);
+    } else if (dest[0] != MP_OBJ_NULL) {
+        dest[2] = rhs_in;
+        res = mp_call_method_n_kw(1, 0, dest);
+    } else {
+        // If this was an inplace method, fallback to normal method
+        // https://docs.python.org/3/reference/datamodel.html#object.__iadd__ :
+        // "If a specific method is not defined, the augmented assignment
+        // falls back to the normal methods."
+        if (op >= MP_BINARY_OP_INPLACE_OR && op <= MP_BINARY_OP_INPLACE_POWER) {
+            op -= MP_BINARY_OP_INPLACE_OR - MP_BINARY_OP_OR;
+            goto retry;
+        }
+        return MP_OBJ_NULL; // op not supported
+    }
+
+    #if MICROPY_PY_BUILTINS_NOTIMPLEMENTED
+    // NotImplemented means "try other fallbacks (like calling __rop__
+    // instead of __op__) and if nothing works, raise TypeError". As
+    // MicroPython doesn't implement any fallbacks, signal to raise
+    // TypeError right away.
+    if (res == mp_const_notimplemented) {
+        return MP_OBJ_NULL; // op not supported
+    }
+    #endif
+
+    return res;
+}
+
+STATIC void mp_obj_instance_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+    // logic: look in instance members then class locals
+    assert(mp_obj_is_instance_type(mp_obj_get_type(self_in)));
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+
+    // Note: This is fast-path'ed in the VM for the MP_BC_LOAD_ATTR operation.
+    mp_map_elem_t *elem = mp_map_lookup(&self->members, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP);
+    if (elem != NULL) {
+        // object member, always treated as a value
+        dest[0] = elem->value;
+        return;
+    }
+    #if MICROPY_CPYTHON_COMPAT
+    if (attr == MP_QSTR___dict__) {
+        // Create a new dict with a copy of the instance's map items.
+        // This creates, unlike CPython, a read-only __dict__ that can't be modified.
+        mp_obj_dict_t dict;
+        dict.base.type = &mp_type_dict;
+        dict.map = self->members;
+        dest[0] = mp_obj_dict_copy(MP_OBJ_FROM_PTR(&dict));
+        mp_obj_dict_t *dest_dict = MP_OBJ_TO_PTR(dest[0]);
+        dest_dict->map.is_fixed = 1;
+        return;
+    }
+    #endif
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = attr,
+        .meth_offset = 0,
+        .dest = dest,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+    mp_obj_t member = dest[0];
+    if (member != MP_OBJ_NULL) {
+        if (!(self->base.type->flags & MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS)) {
+            // Class doesn't have any special accessors to check so return straightaway
+            return;
+        }
+
+        #if MICROPY_PY_BUILTINS_PROPERTY
+        if (mp_obj_is_type(member, &mp_type_property)) {
+            // object member is a property; delegate the load to the property
+            // Note: This is an optimisation for code size and execution time.
+            // The proper way to do it is have the functionality just below
+            // in a __get__ method of the property object, and then it would
+            // be called by the descriptor code down below.  But that way
+            // requires overhead for the nested mp_call's and overhead for
+            // the code.
+            size_t n_proxy;
+            const mp_obj_t *proxy = mp_obj_property_get(member, &n_proxy);
+            if (proxy[0] == mp_const_none) {
+                mp_raise_AttributeError(MP_ERROR_TEXT("unreadable attribute"));
+            } else {
+                dest[0] = mp_call_function_n_kw(proxy[0], 1, 0, &self_in);
+            }
+            return;
+        }
+        #endif
+
+        #if MICROPY_PY_DESCRIPTORS
+        // found a class attribute; if it has a __get__ method then call it with the
+        // class instance and class as arguments and return the result
+        // Note that this is functionally correct but very slow: each load_attr
+        // requires an extra mp_load_method_maybe to check for the __get__.
+        mp_obj_t attr_get_method[4];
+        mp_load_method_maybe(member, MP_QSTR___get__, attr_get_method);
+        if (attr_get_method[0] != MP_OBJ_NULL) {
+            attr_get_method[2] = self_in;
+            attr_get_method[3] = MP_OBJ_FROM_PTR(mp_obj_get_type(self_in));
+            dest[0] = mp_call_method_n_kw(2, 0, attr_get_method);
+        }
+        #endif
+        return;
+    }
+
+    // try __getattr__
+    if (attr != MP_QSTR___getattr__) {
+        #if MICROPY_PY_DELATTR_SETATTR
+        // If the requested attr is __setattr__/__delattr__ then don't delegate the lookup
+        // to __getattr__.  If we followed CPython's behaviour then __setattr__/__delattr__
+        // would have already been found in the "object" base class.
+        if (attr == MP_QSTR___setattr__ || attr == MP_QSTR___delattr__) {
+            return;
+        }
+        #endif
+
+        mp_obj_t dest2[3];
+        mp_load_method_maybe(self_in, MP_QSTR___getattr__, dest2);
+        if (dest2[0] != MP_OBJ_NULL) {
+            // __getattr__ exists, call it and return its result
+            dest2[2] = MP_OBJ_NEW_QSTR(attr);
+            dest[0] = mp_call_method_n_kw(1, 0, dest2);
+            return;
+        }
+    }
+}
+
+STATIC bool mp_obj_instance_store_attr(mp_obj_t self_in, qstr attr, mp_obj_t value) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+
+    if (!(self->base.type->flags & MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS)) {
+        // Class doesn't have any special accessors so skip their checks
+        goto skip_special_accessors;
+    }
+
+    #if MICROPY_PY_BUILTINS_PROPERTY || MICROPY_PY_DESCRIPTORS
+    // With property and/or descriptors enabled we need to do a lookup
+    // first in the class dict for the attribute to see if the store should
+    // be delegated.
+    mp_obj_t member[2] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = attr,
+        .meth_offset = 0,
+        .dest = member,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+
+    if (member[0] != MP_OBJ_NULL) {
+        #if MICROPY_PY_BUILTINS_PROPERTY
+        if (mp_obj_is_type(member[0], &mp_type_property)) {
+            // attribute exists and is a property; delegate the store/delete
+            // Note: This is an optimisation for code size and execution time.
+            // The proper way to do it is have the functionality just below in
+            // a __set__/__delete__ method of the property object, and then it
+            // would be called by the descriptor code down below.  But that way
+            // requires overhead for the nested mp_call's and overhead for
+            // the code.
+            size_t n_proxy;
+            const mp_obj_t *proxy = mp_obj_property_get(member[0], &n_proxy);
+            mp_obj_t dest[2] = {self_in, value};
+            if (value == MP_OBJ_NULL) {
+                // delete attribute
+                if (n_proxy < 3 || proxy[2] == mp_const_none) {
+                    // TODO better error message?
+                    return false;
+                } else {
+                    mp_call_function_n_kw(proxy[2], 1, 0, dest);
+                    return true;
+                }
+            } else {
+                // store attribute
+                if (n_proxy < 2 || proxy[1] == mp_const_none) {
+                    // TODO better error message?
+                    return false;
+                } else {
+                    mp_call_function_n_kw(proxy[1], 2, 0, dest);
+                    return true;
+                }
+            }
+        }
+        #endif
+
+        #if MICROPY_PY_DESCRIPTORS
+        // found a class attribute; if it has a __set__/__delete__ method then
+        // call it with the class instance (and value) as arguments
+        if (value == MP_OBJ_NULL) {
+            // delete attribute
+            mp_obj_t attr_delete_method[3];
+            mp_load_method_maybe(member[0], MP_QSTR___delete__, attr_delete_method);
+            if (attr_delete_method[0] != MP_OBJ_NULL) {
+                attr_delete_method[2] = self_in;
+                mp_call_method_n_kw(1, 0, attr_delete_method);
+                return true;
+            }
+        } else {
+            // store attribute
+            mp_obj_t attr_set_method[4];
+            mp_load_method_maybe(member[0], MP_QSTR___set__, attr_set_method);
+            if (attr_set_method[0] != MP_OBJ_NULL) {
+                attr_set_method[2] = self_in;
+                attr_set_method[3] = value;
+                mp_call_method_n_kw(2, 0, attr_set_method);
+                return true;
+            }
+        }
+        #endif
+    }
+    #endif
+
+    #if MICROPY_PY_DELATTR_SETATTR
+    if (value == MP_OBJ_NULL) {
+        // delete attribute
+        // try __delattr__ first
+        mp_obj_t attr_delattr_method[3];
+        mp_load_method_maybe(self_in, MP_QSTR___delattr__, attr_delattr_method);
+        if (attr_delattr_method[0] != MP_OBJ_NULL) {
+            // __delattr__ exists, so call it
+            attr_delattr_method[2] = MP_OBJ_NEW_QSTR(attr);
+            mp_call_method_n_kw(1, 0, attr_delattr_method);
+            return true;
+        }
+    } else {
+        // store attribute
+        // try __setattr__ first
+        mp_obj_t attr_setattr_method[4];
+        mp_load_method_maybe(self_in, MP_QSTR___setattr__, attr_setattr_method);
+        if (attr_setattr_method[0] != MP_OBJ_NULL) {
+            // __setattr__ exists, so call it
+            attr_setattr_method[2] = MP_OBJ_NEW_QSTR(attr);
+            attr_setattr_method[3] = value;
+            mp_call_method_n_kw(2, 0, attr_setattr_method);
+            return true;
+        }
+    }
+    #endif
+
+skip_special_accessors:
+
+    if (value == MP_OBJ_NULL) {
+        // delete attribute
+        mp_map_elem_t *elem = mp_map_lookup(&self->members, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP_REMOVE_IF_FOUND);
+        return elem != NULL;
+    } else {
+        // store attribute
+        mp_map_lookup(&self->members, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND)->value = value;
+        return true;
+    }
+}
+
+STATIC void mp_obj_instance_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+    if (dest[0] == MP_OBJ_NULL) {
+        mp_obj_instance_load_attr(self_in, attr, dest);
+    } else {
+        if (mp_obj_instance_store_attr(self_in, attr, dest[1])) {
+            dest[0] = MP_OBJ_NULL; // indicate success
+        }
+    }
+}
+
+STATIC mp_obj_t instance_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_obj_t member[4] = {MP_OBJ_NULL, MP_OBJ_NULL, index, value};
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .meth_offset = offsetof(mp_obj_type_t, ext[0].subscr),
+        .dest = member,
+        .is_type = false,
+    };
+    if (value == MP_OBJ_NULL) {
+        // delete item
+        lookup.attr = MP_QSTR___delitem__;
+    } else if (value == MP_OBJ_SENTINEL) {
+        // load item
+        lookup.attr = MP_QSTR___getitem__;
+    } else {
+        // store item
+        lookup.attr = MP_QSTR___setitem__;
+    }
+    mp_obj_class_lookup(&lookup, self->base.type);
+    if (member[0] == MP_OBJ_SENTINEL) {
+        const mp_obj_type_t *subobj_type = mp_obj_get_type(self->subobj[0]);
+        mp_obj_t ret = subobj_type->ext[0].subscr(self_in, index, value);
+        // May have called port specific C code. Make sure it didn't mess up the heap.
+        assert_heap_ok();
+        return ret;
+    } else if (member[0] != MP_OBJ_NULL) {
+        size_t n_args = value == MP_OBJ_NULL || value == MP_OBJ_SENTINEL ? 1 : 2;
+        mp_obj_t ret = mp_call_method_n_kw(n_args, 0, member);
+        if (value == MP_OBJ_SENTINEL) {
+            return ret;
+        } else {
+            return mp_const_none;
+        }
+    } else {
+        return MP_OBJ_NULL; // op not supported
+    }
+}
+
+STATIC mp_obj_t mp_obj_instance_get_call(mp_obj_t self_in, mp_obj_t *member) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = MP_QSTR___call__,
+        .meth_offset = offsetof(mp_obj_type_t, ext[0].call),
+        .dest = member,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+    return member[0];
+}
+
+bool mp_obj_instance_is_callable(mp_obj_t self_in) {
+    mp_obj_t member[2] = {MP_OBJ_NULL, MP_OBJ_NULL};
+    return mp_obj_instance_get_call(self_in, member) != MP_OBJ_NULL;
+}
+
+mp_obj_t mp_obj_instance_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    mp_obj_t member[2] = {MP_OBJ_NULL, MP_OBJ_NULL};
+    mp_obj_t call = mp_obj_instance_get_call(self_in, member);
+    if (call == MP_OBJ_NULL) {
+        #if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_TERSE
+        mp_raise_TypeError(MP_ERROR_TEXT("object not callable"));
+        #else
+        mp_raise_TypeError_varg(MP_ERROR_TEXT("'%q' object is not callable"),
+            mp_obj_get_type_qstr(self_in));
+        #endif
+    }
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+    if (call == MP_OBJ_SENTINEL) {
+        return mp_call_function_n_kw(self->subobj[0], n_args, n_kw, args);
+    }
+
+    return mp_call_method_self_n_kw(member[0], member[1], n_args, n_kw, args);
+}
+
+// Note that iter_buf may be NULL, and needs to be allocated if needed
+mp_obj_t mp_obj_instance_getiter(mp_obj_t self_in, mp_obj_iter_buf_t *iter_buf) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_obj_t member[2] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = MP_QSTR___iter__,
+        .meth_offset = offsetof(mp_obj_type_t, ext[0].getiter),
+        .dest = member,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+    if (member[0] == MP_OBJ_NULL) {
+        return MP_OBJ_NULL;
+    } else if (member[0] == MP_OBJ_SENTINEL) {
+        const mp_obj_type_t *type = mp_obj_get_type(self->subobj[0]);
+        if (iter_buf == NULL) {
+            iter_buf = m_new_obj(mp_obj_iter_buf_t);
+        }
+        return type->ext[0].getiter(self->subobj[0], iter_buf);
+    } else {
+        return mp_call_method_n_kw(0, 0, member);
+    }
+}
+
+STATIC mp_int_t instance_get_buffer(mp_obj_t self_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
+    mp_obj_instance_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_obj_t member[2] = {MP_OBJ_NULL};
+    struct class_lookup_data lookup = {
+        .obj = self,
+        .attr = MP_QSTR_, // don't actually look for a method
+        .meth_offset = offsetof(mp_obj_type_t, ext[0].buffer_p.get_buffer),
+        .dest = member,
+        .is_type = false,
+    };
+    mp_obj_class_lookup(&lookup, self->base.type);
+    if (member[0] == MP_OBJ_SENTINEL) {
+        const mp_obj_type_t *type = mp_obj_get_type(self->subobj[0]);
+        return type->ext[0].buffer_p.get_buffer(self->subobj[0], bufinfo, flags);
+    } else {
+        return 1; // object does not support buffer protocol
+    }
+}
+
+/******************************************************************************/
+// type object
+//  - the struct is mp_obj_type_t and is defined in obj.h so const types can be made
+//  - there is a constant mp_obj_type_t (called mp_type_type) for the 'type' object
+//  - creating a new class (a new type) creates a new mp_obj_type_t
+
+#if ENABLE_SPECIAL_ACCESSORS
+STATIC bool check_for_special_accessors(mp_obj_t key, mp_obj_t value) {
+    #if MICROPY_PY_DELATTR_SETATTR
+    if (key == MP_OBJ_NEW_QSTR(MP_QSTR___setattr__) || key == MP_OBJ_NEW_QSTR(MP_QSTR___delattr__)) {
+        return true;
+    }
+    #endif
+    #if MICROPY_PY_BUILTINS_PROPERTY
+    if (mp_obj_is_type(value, &mp_type_property)) {
+        return true;
+    }
+    #endif
+    #if MICROPY_PY_DESCRIPTORS
+    static const uint8_t to_check[] = {
+        MP_QSTR___get__, MP_QSTR___set__, MP_QSTR___delete__,
+    };
+    for (size_t i = 0; i < MP_ARRAY_SIZE(to_check); ++i) {
+        mp_obj_t dest_temp[2];
+        mp_load_method_protected(value, to_check[i], dest_temp, true);
+        if (dest_temp[0] != MP_OBJ_NULL) {
+            return true;
+        }
+    }
+    #endif
+    return false;
+}
+
+STATIC bool map_has_special_accessors(const mp_map_t *map) {
+    if (map == NULL) {
+        return false;
+    }
+    for (size_t i = 0; i < map->alloc; i++) {
+        if (mp_map_slot_is_filled(map, i)) {
+            const mp_map_elem_t *elem = &map->table[i];
+            if (check_for_special_accessors(elem->key, elem->value)) {
+                return true;
+            }
+        }
+    }
+    return false;
+}
+#endif
+
+STATIC void type_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    (void)kind;
+    mp_obj_type_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_printf(print, "<class '%q'>", self->name);
+}
+
+STATIC mp_obj_t type_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    (void)type_in;
+
+    mp_arg_check_num(n_args, n_kw, 1, 3, false);
+
+    switch (n_args) {
+        case 1:
+            return MP_OBJ_FROM_PTR(mp_obj_get_type(args[0]));
+
+        case 3:
+            // args[0] = name
+            // args[1] = bases tuple
+            // args[2] = locals dict
+            return mp_obj_new_type(mp_obj_str_get_qstr(args[0]), args[1], args[2]);
+
+        default:
+            mp_raise_TypeError(MP_ERROR_TEXT("type takes 1 or 3 arguments"));
+    }
+}
+
+STATIC mp_obj_t type_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    // instantiate an instance of a class
+
+    mp_obj_type_t *self = MP_OBJ_TO_PTR(self_in);
+
+    if (self->make_new == NULL) {
+        #if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_TERSE
+        mp_raise_TypeError(MP_ERROR_TEXT("cannot create instance"));
+        #else
+        mp_raise_TypeError_varg(MP_ERROR_TEXT("cannot create '%q' instances"), self->name);
+        #endif
+    }
+
+    mp_obj_t o = self->make_new(self, n_args, n_kw, args);
+
+    // return new instance
+    return o;
+}
+
+STATIC void type_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+    assert(mp_obj_is_type(self_in, &mp_type_type));
+    mp_obj_type_t *self = MP_OBJ_TO_PTR(self_in);
+
+    if (dest[0] == MP_OBJ_NULL) {
+        // load attribute
+        #if MICROPY_CPYTHON_COMPAT
+        if (attr == MP_QSTR___name__) {
+            dest[0] = MP_OBJ_NEW_QSTR(self->name);
+            return;
+        }
+        #if MICROPY_CPYTHON_COMPAT
+        if (attr == MP_QSTR___dict__) {
+            // Returns a read-only dict of the class attributes.
+            // If the internal locals is not fixed, a copy will be created.
+            const mp_obj_dict_t *dict = self->locals_dict;
+            if (!dict) {
+                dict = &mp_const_empty_dict_obj;
+            }
+            if (dict->map.is_fixed) {
+                dest[0] = MP_OBJ_FROM_PTR(dict);
+            } else {
+                dest[0] = mp_obj_dict_copy(MP_OBJ_FROM_PTR(dict));
+                mp_obj_dict_t *dict_copy = MP_OBJ_TO_PTR(dest[0]);
+                dict_copy->map.is_fixed = 1;
+            }
+            return;
+        }
+        #endif
+        if (attr == MP_QSTR___bases__) {
+            if (self == &mp_type_object) {
+                dest[0] = mp_const_empty_tuple;
+                return;
+            }
+            const void *parent = mp_type_get_parent_slot(self);
+            mp_obj_t parent_obj = parent ? MP_OBJ_FROM_PTR(parent) : MP_OBJ_FROM_PTR(&mp_type_object);
+            #if MICROPY_MULTIPLE_INHERITANCE
+            if (mp_obj_is_type(parent_obj, &mp_type_tuple)) {
+                dest[0] = parent_obj;
+                return;
+            }
+            #endif
+            dest[0] = mp_obj_new_tuple(1, &parent_obj);
+            return;
+        }
+        #endif
+        struct class_lookup_data lookup = {
+            .obj = (mp_obj_instance_t *)self,
+            .attr = attr,
+            .meth_offset = 0,
+            .dest = dest,
+            .is_type = true,
+        };
+        mp_obj_class_lookup(&lookup, self);
+    } else {
+        // delete/store attribute
+
+        if (self->locals_dict != NULL) {
+            assert(mp_obj_is_dict_or_ordereddict(MP_OBJ_FROM_PTR(self->locals_dict))); // MicroPython restriction, for now
+            mp_map_t *locals_map = &self->locals_dict->map;
+            if (locals_map->is_fixed) {
+                // can't apply delete/store to a fixed map
+                return;
+            }
+            if (dest[1] == MP_OBJ_NULL) {
+                // delete attribute
+                mp_map_elem_t *elem = mp_map_lookup(locals_map, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP_REMOVE_IF_FOUND);
+                if (elem != NULL) {
+                    dest[0] = MP_OBJ_NULL; // indicate success
+                }
+            } else {
+                #if ENABLE_SPECIAL_ACCESSORS
+                // Check if we add any special accessor methods with this store
+                if (!(self->flags & MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS)) {
+                    if (check_for_special_accessors(MP_OBJ_NEW_QSTR(attr), dest[1])) {
+                        if (self->flags & MP_TYPE_FLAG_IS_SUBCLASSED) {
+                            // This class is already subclassed so can't have special accessors added
+                            mp_raise_msg(&mp_type_AttributeError, MP_ERROR_TEXT("can't add special method to already-subclassed class"));
+                        }
+                        self->flags |= MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS;
+                    }
+                }
+                #endif
+
+                // store attribute
+                mp_map_elem_t *elem = mp_map_lookup(locals_map, MP_OBJ_NEW_QSTR(attr), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND);
+                elem->value = dest[1];
+                dest[0] = MP_OBJ_NULL; // indicate success
+            }
+        }
+    }
+}
+
+const mp_obj_type_t mp_type_type = {
+    { &mp_type_type },
+    .flags = MP_TYPE_FLAG_EXTENDED,
+    .name = MP_QSTR_type,
+    .print = type_print,
+    .make_new = type_make_new,
+    .attr = type_attr,
+    MP_TYPE_EXTENDED_FIELDS(
+        .call = type_call,
+        .unary_op = mp_generic_unary_op,
+        ),
+};
+
+mp_obj_t mp_obj_new_type(qstr name, mp_obj_t bases_tuple, mp_obj_t locals_dict) {
+    // Verify input objects have expected type
+    if (!mp_obj_is_type(bases_tuple, &mp_type_tuple)) {
+        mp_raise_TypeError(NULL);
+    }
+    if (!mp_obj_is_dict_or_ordereddict(locals_dict)) {
+        mp_raise_TypeError(NULL);
+    }
+
+    // TODO might need to make a copy of locals_dict; at least that's how CPython does it
+
+    // Basic validation of base classes
+    uint16_t base_flags = MP_TYPE_FLAG_EQ_NOT_REFLEXIVE
+        | MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE | MP_TYPE_FLAG_EQ_HAS_NEQ_TEST | MP_TYPE_FLAG_EXTENDED;
+    size_t bases_len;
+    mp_obj_t *bases_items;
+    mp_obj_tuple_get(bases_tuple, &bases_len, &bases_items);
+    for (size_t i = 0; i < bases_len; i++) {
+        if (!mp_obj_is_type(bases_items[i], &mp_type_type)) {
+            mp_raise_TypeError(MP_ERROR_TEXT("type is not an acceptable base type"));
+        }
+        mp_obj_type_t *t = MP_OBJ_TO_PTR(bases_items[i]);
+        // TODO: Verify with CPy, tested on function type
+        if (t->make_new == NULL) {
+            #if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_TERSE
+            mp_raise_TypeError(MP_ERROR_TEXT("type is not an acceptable base type"));
+            #else
+            mp_raise_TypeError_varg(
+                MP_ERROR_TEXT("type '%q' is not an acceptable base type"), t->name);
+            #endif
+        }
+        #if ENABLE_SPECIAL_ACCESSORS
+        if (mp_obj_is_instance_type(t)) {
+            t->flags |= MP_TYPE_FLAG_IS_SUBCLASSED;
+            base_flags |= t->flags & MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS;
+        }
+        #endif
+    }
+
+    mp_obj_full_type_t *o = m_new0_ll(mp_obj_full_type_t, 1);
+    o->base.type = &mp_type_type;
+    o->flags = base_flags;
+    o->name = name;
+    o->print = instance_print;
+    o->make_new = mp_obj_instance_make_new;
+    o->attr = mp_obj_instance_attr;
+    o->MP_TYPE_CALL = mp_obj_instance_call;
+    o->MP_TYPE_UNARY_OP = instance_unary_op;
+    o->MP_TYPE_BINARY_OP = instance_binary_op;
+    o->MP_TYPE_SUBSCR = instance_subscr;
+    o->MP_TYPE_GETITER = mp_obj_instance_getiter;
+    // o->iternext = ; not implemented
+    o->MP_TYPE_GET_BUFFER = instance_get_buffer;
+
+    if (bases_len > 0) {
+        // Inherit protocol from a base class. This allows to define an
+        // abstract base class which would translate C-level protocol to
+        // Python method calls, and any subclass inheriting from it will
+        // support this feature.
+        o->MP_TYPE_PROTOCOL = mp_type_get_protocol_slot((mp_obj_type_t *)MP_OBJ_TO_PTR(bases_items[0]));
+
+        if (bases_len >= 2) {
+            #if MICROPY_MULTIPLE_INHERITANCE
+            o->parent = MP_OBJ_TO_PTR(bases_tuple);
+            #else
+            mp_raise_NotImplementedError(MP_ERROR_TEXT("multiple inheritance not supported"));
+            #endif
+        } else {
+            o->parent = MP_OBJ_TO_PTR(bases_items[0]);
+        }
+    }
+
+    o->locals_dict = make_dict_long_lived(MP_OBJ_TO_PTR(locals_dict), 10);
+
+    #if ENABLE_SPECIAL_ACCESSORS
+    // Check if the class has any special accessor methods
+    if (!(o->flags & MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS)) {
+        for (size_t i = 0; i < o->locals_dict->map.alloc; i++) {
+            if (mp_map_slot_is_filled(&o->locals_dict->map, i)) {
+                const mp_map_elem_t *elem = &o->locals_dict->map.table[i];
+                if (check_for_special_accessors(elem->key, elem->value)) {
+                    o->flags |= MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS;
+                    break;
+                }
+            }
+        }
+    }
+    #endif
+
+    const mp_obj_type_t *native_base;
+    size_t num_native_bases = instance_count_native_bases((mp_obj_type_t *)o, &native_base);
+    if (num_native_bases > 1) {
+        mp_raise_TypeError(MP_ERROR_TEXT("multiple bases have instance lay-out conflict"));
+    }
+
+    mp_map_t *locals_map = &o->locals_dict->map;
+    #if ENABLE_SPECIAL_ACCESSORS
+    // Check if the class has any special accessor methods
+    if (!(o->flags & MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS) &&
+        (map_has_special_accessors(locals_map) ||
+         (num_native_bases == 1 &&
+          native_base->locals_dict != NULL &&
+          map_has_special_accessors(&native_base->locals_dict->map)))) {
+        o->flags |= MP_TYPE_FLAG_HAS_SPECIAL_ACCESSORS;
+    }
+    #endif
+
+    mp_map_elem_t *elem = mp_map_lookup(locals_map, MP_OBJ_NEW_QSTR(MP_QSTR___new__), MP_MAP_LOOKUP);
+    if (elem != NULL) {
+        // __new__ slot exists; check if it is a function
+        if (mp_obj_is_fun(elem->value)) {
+            // __new__ is a function, wrap it in a staticmethod decorator
+            elem->value = static_class_method_make_new(&mp_type_staticmethod, 1, 0, &elem->value);
+        }
+    }
+
+    return MP_OBJ_FROM_PTR(o);
+}
+
+/******************************************************************************/
+// super object
+
+typedef struct _mp_obj_super_t {
+    mp_obj_base_t base;
+    mp_obj_t type;
+    mp_obj_t obj;
+} mp_obj_super_t;
+
+STATIC void super_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    (void)kind;
+    mp_obj_super_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_print_str(print, "<super: ");
+    mp_obj_print_helper(print, self->type, PRINT_STR);
+    mp_print_str(print, ", ");
+    mp_obj_print_helper(print, self->obj, PRINT_STR);
+    mp_print_str(print, ">");
+}
+
+STATIC mp_obj_t super_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    (void)type_in;
+    // 0 arguments are turned into 2 in the compiler
+    // 1 argument is not yet implemented
+    mp_arg_check_num(n_args, n_kw, 2, 2, false);
+    if (!mp_obj_is_type(args[0], &mp_type_type)) {
+        mp_raise_TypeError(MP_ERROR_TEXT("first argument to super() must be type"));
+    }
+    mp_obj_super_t *o = m_new_obj(mp_obj_super_t);
+    *o = (mp_obj_super_t) {{type_in}, args[0], args[1]};
+    return MP_OBJ_FROM_PTR(o);
+}
+
+STATIC void super_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+    if (dest[0] != MP_OBJ_NULL) {
+        // not load attribute
+        return;
+    }
+
+    assert(mp_obj_is_type(self_in, &mp_type_super));
+    mp_obj_super_t *self = MP_OBJ_TO_PTR(self_in);
+
+    assert(mp_obj_is_type(self->type, &mp_type_type));
+
+    mp_obj_type_t *type = MP_OBJ_TO_PTR(self->type);
+
+    struct class_lookup_data lookup = {
+        .obj = MP_OBJ_TO_PTR(self->obj),
+        .attr = attr,
+        .meth_offset = 0,
+        .dest = dest,
+        .is_type = false,
+    };
+
+    // Allow a call super().__init__() to reach any native base classes
+    if (attr == MP_QSTR___init__) {
+        lookup.meth_offset = offsetof(mp_obj_type_t, make_new);
+    }
+
+    const void *parent = mp_type_get_parent_slot(type);
+    if (parent == NULL) {
+        // no parents, do nothing
+    #if MICROPY_MULTIPLE_INHERITANCE
+    } else if (((mp_obj_base_t *)parent)->type == &mp_type_tuple) {
+        const mp_obj_tuple_t *parent_tuple = parent;
+        size_t len = parent_tuple->len;
+        const mp_obj_t *items = parent_tuple->items;
+        for (size_t i = 0; i < len; i++) {
+            assert(mp_obj_is_type(items[i], &mp_type_type));
+            if (MP_OBJ_TO_PTR(items[i]) == &mp_type_object) {
+                // The "object" type will be searched at the end of this function,
+                // and we don't want to lookup native methods in object.
+                continue;
+            }
+            mp_obj_class_lookup(&lookup, (mp_obj_type_t *)MP_OBJ_TO_PTR(items[i]));
+            if (dest[0] != MP_OBJ_NULL) {
+                break;
+            }
+        }
+    #endif
+    } else if (parent != &mp_type_object) {
+        mp_obj_class_lookup(&lookup, parent);
+    }
+
+    if (dest[0] != MP_OBJ_NULL) {
+        if (dest[0] == MP_OBJ_SENTINEL) {
+            // Looked up native __init__ so defer to it
+            dest[0] = MP_OBJ_FROM_PTR(&native_base_init_wrapper_obj);
+            dest[1] = self->obj;
+        } else {
+            mp_obj_t member = dest[0];
+            // changes to mp_obj_instance_load_attr may require changes
+            // here...
+            #if MICROPY_PY_BUILTINS_PROPERTY
+            if (mp_obj_is_type(member, &mp_type_property)) {
+                size_t n_proxy;
+                const mp_obj_t *proxy = mp_obj_property_get(member, &n_proxy);
+                if (proxy[0] == mp_const_none) {
+                    mp_raise_AttributeError(MP_ERROR_TEXT("unreadable attribute"));
+                } else {
+                    dest[0] = mp_call_function_n_kw(proxy[0], 1, 0, &self_in);
+                }
+            }
+            #endif
+            #if MICROPY_PY_DESCRIPTORS
+            mp_obj_t attr_get_method[4];
+            mp_load_method_maybe(member, MP_QSTR___get__, attr_get_method);
+            if (attr_get_method[0] != MP_OBJ_NULL) {
+                attr_get_method[2] = self_in;
+                attr_get_method[3] = MP_OBJ_FROM_PTR(mp_obj_get_type(self_in));
+                dest[0] = mp_call_method_n_kw(2, 0, attr_get_method);
+            }
+            #endif
+        }
+        return;
+    }
+
+    // Reset meth_offset so we don't look up any native methods in object,
+    // because object never takes up the native base-class slot.
+    lookup.meth_offset = 0;
+
+    mp_obj_class_lookup(&lookup, &mp_type_object);
+}
+
+const mp_obj_type_t mp_type_super = {
+    { &mp_type_type },
+    .name = MP_QSTR_super,
+    .print = super_print,
+    .make_new = super_make_new,
+    .attr = super_attr,
+};
+
+void mp_load_super_method(qstr attr, mp_obj_t *dest) {
+    mp_obj_super_t super = {{&mp_type_super}, dest[1], dest[2]};
+    mp_load_method(MP_OBJ_FROM_PTR(&super), attr, dest);
+}
+
+/******************************************************************************/
+// subclassing and built-ins specific to types
+
+// object and classinfo should be type objects
+// (but the function will fail gracefully if they are not)
+bool mp_obj_is_subclass_fast(mp_const_obj_t object, mp_const_obj_t classinfo) {
+    for (;;) {
+        if (object == classinfo) {
+            return true;
+        }
+
+        // not equivalent classes, keep searching base classes
+
+        // object should always be a type object, but just return false if it's not
+        if (!mp_obj_is_type(object, &mp_type_type)) {
+            return false;
+        }
+
+        const mp_obj_type_t *self = MP_OBJ_TO_PTR(object);
+        const void *parent = mp_type_get_parent_slot(self);
+
+        if (parent == NULL) {
+            // type has no parents
+            return false;
+        #if MICROPY_MULTIPLE_INHERITANCE
+        } else if (((mp_obj_base_t *)parent)->type == &mp_type_tuple) {
+            // get the base objects (they should be type objects)
+            const mp_obj_tuple_t *parent_tuple = parent;
+            const mp_obj_t *item = parent_tuple->items;
+            const mp_obj_t *top = item + parent_tuple->len - 1;
+
+            // iterate through the base objects
+            for (; item < top; ++item) {
+                if (mp_obj_is_subclass_fast(*item, classinfo)) {
+                    return true;
+                }
+            }
+
+            // search last base (simple tail recursion elimination)
+            object = *item;
+        #endif
+        } else {
+            // type has 1 parent
+            object = MP_OBJ_FROM_PTR(parent);
+        }
+    }
+}
+
+STATIC mp_obj_t mp_obj_is_subclass(mp_obj_t object, mp_obj_t classinfo) {
+    size_t len;
+    mp_obj_t *items;
+    if (mp_obj_is_type(classinfo, &mp_type_type)) {
+        len = 1;
+        items = &classinfo;
+    } else if (mp_obj_is_type(classinfo, &mp_type_tuple)) {
+        mp_obj_tuple_get(classinfo, &len, &items);
+    } else {
+        mp_raise_TypeError(MP_ERROR_TEXT("issubclass() arg 2 must be a class or a tuple of classes"));
+    }
+
+    for (size_t i = 0; i < len; i++) {
+        // We explicitly check for 'object' here since no-one explicitly derives from it
+        if (items[i] == MP_OBJ_FROM_PTR(&mp_type_object) || mp_obj_is_subclass_fast(object, items[i])) {
+            return mp_const_true;
+        }
+    }
+    return mp_const_false;
+}
+
+STATIC mp_obj_t mp_builtin_issubclass(mp_obj_t object, mp_obj_t classinfo) {
+    if (!mp_obj_is_type(object, &mp_type_type)) {
+        mp_raise_TypeError(MP_ERROR_TEXT("issubclass() arg 1 must be a class"));
+    }
+    return mp_obj_is_subclass(object, classinfo);
+}
+
+MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_issubclass_obj, mp_builtin_issubclass);
+
+STATIC mp_obj_t mp_builtin_isinstance(mp_obj_t object, mp_obj_t classinfo) {
+    return mp_obj_is_subclass(MP_OBJ_FROM_PTR(mp_obj_get_type(object)), classinfo);
+}
+
+MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_isinstance_obj, mp_builtin_isinstance);
+
+mp_obj_t mp_obj_cast_to_native_base(mp_obj_t self_in, mp_const_obj_t native_type) {
+    const mp_obj_type_t *self_type = mp_obj_get_type(self_in);
+
+    if (MP_OBJ_FROM_PTR(self_type) == native_type) {
+        return self_in;
+    } else if (!mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(self_type), native_type)) {
+        return MP_OBJ_NULL;
+    } else {
+        mp_obj_instance_t *self = (mp_obj_instance_t *)MP_OBJ_TO_PTR(self_in);
+        return self->subobj[0];
+    }
+}
+
+/******************************************************************************/
+// staticmethod and classmethod types (probably should go in a different file)
+
+STATIC mp_obj_t static_class_method_make_new(const mp_obj_type_t *self, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    assert(self == &mp_type_staticmethod || self == &mp_type_classmethod);
+
+    mp_arg_check_num(n_args, n_kw, 1, 1, false);
+
+    mp_obj_static_class_method_t *o = m_new_obj(mp_obj_static_class_method_t);
+    *o = (mp_obj_static_class_method_t) {{self}, args[0]};
+    return MP_OBJ_FROM_PTR(o);
+}
+
+const mp_obj_type_t mp_type_staticmethod = {
+    { &mp_type_type },
+    .name = MP_QSTR_staticmethod,
+    .make_new = static_class_method_make_new,
+};
+
+const mp_obj_type_t mp_type_classmethod = {
+    { &mp_type_type },
+    .name = MP_QSTR_classmethod,
+    .make_new = static_class_method_make_new,
+};