Some compilers do not accept `.mp_obj_type` in 1.20

[embeddedt]

I'm finding that Emscripten's clang version is refusing to accept the way some structs are being initialized now. This doesn't happen before the 1.20 merge so I assume it's related to upstream changing how object types are defined. Any ideas?

build/lvgl/lv_mpy.c:1138:20: error: initializer element is not a compile-time constant
    .mp_obj_type = mp_lv_LV_RES_type_base,
                   ^~~~~~~~~~~~~~~~~~~~~~
build/lvgl/lv_mpy.c:1184:20: error: initializer element is not a compile-time constant
    .mp_obj_type = mp_lv_ENUM_LV_LOG_LEVEL_type_base,
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
build/lvgl/lv_mpy.c:1246:20: error: initializer element is not a compile-time constant
    .mp_obj_type = mp_lv_LV_ALIGN_type_base,
                   ^~~~~~~~~~~~~~~~~~~~~~~~
build/lvgl/lv_mpy.c:1294:20: error: initializer element is not a compile-time constant
    .mp_obj_type = mp_lv_LV_DIR_type_base,

Code near line 1246

```c STATIC MP_DEFINE_CONST_OBJ_TYPE( mp_lv_LV_ALIGN_type_base, MP_QSTR_LV_ALIGN, MP_TYPE_FLAG_NONE, print, LV_ALIGN_print, attr, call_parent_methods, locals_dict, &LV_ALIGN_locals_dict ); STATIC const mp_lv_obj_type_t mp_lv_LV_ALIGN_type = { #ifdef LV_OBJ_T .lv_obj_class = NULL, #endif .mp_obj_type = mp_lv_LV_ALIGN_type_base, }; ```

[amirgon]

Strange. All Micropython types are now defined in the new way, so all ports including wasm are already using them.

Indeed, mp_lv_LV_ALIGN_type_base should be a compile-time constant because mp_lv_LV_ALIGN_type is defined static (When initializing an object of static or thread-local storage duration, every expression in the initializer must be a constant expression or string literal) - but it is! since it's defined itself as STATIC MP_DEFINE_CONST_OBJ_TYPE

I can find examples in upstream Micropython of doing the same thing. For example:

STATIC MP_DEFINE_CONST_OBJ_TYPE(
    mp_type_thread_lock,
    MP_QSTR_lock,
    MP_TYPE_FLAG_NONE,
    locals_dict, &thread_lock_locals_dict
    );

...

STATIC const mp_rom_map_elem_t mp_module_thread_globals_table[] = {
    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR__thread) },
    { MP_ROM_QSTR(MP_QSTR_LockType), MP_ROM_PTR(&mp_type_thread_lock) },

Here too, mp_type_thread_lock is defined as static with MP_DEFINE_CONST_OBJ_TYPE and used to initialize the static const structure mp_module_thread_globals_table.

Could you try to enable MICROPY_PY_THREAD in ports/webassembly/mpconfigport.h and see if you are getting the same error on upstream micropython?

What is the clang version that you are using? Is it possible to switch clang version on Emscripten?

[embeddedt]

Could you try to enable MICROPY_PY_THREAD in ports/webassembly/mpconfigport.h and see if you are getting the same error on upstream micropython?

I don't get the error when I do that.

What is the clang version that you are using? Is it possible to switch clang version on Emscripten?

The previous version of Emscripten I was using included Clang 13. I'll update to the latest version (which uses Clang 17) and see what happens.

[embeddedt]

Exact same error, unfortunately. -Werror is disabled and there is no -pedantic present, so I'm not sure what is causing this. This is the full compiler invocation:

emcc -Wno-unused-function -DFFCONF_H=\"lib/oofatfs/ffconf.h\" -std=gnu99 -Wall -Wno-error -Wdouble-promotion -Wfloat-conversion -DNDEBUG -Os -I../../lib/lv_bindings -I. -I../.. -Ibuild -I/work/emsdk/upstream/emscripten/cache/sysroot/include/freetype2 -fdata-sections -ffunction-sections -DMICROPY_SDL=1 -DMICROPY_QSTR_EXTRA_POOL=mp_qstr_frozen_const_pool -DMICROPY_MODULE_FROZEN_STR -DMICROPY_MODULE_FROZEN_MPY -D MICROPY_FROZEN_MANIFEST=manifest.py -c -MD -o build/build/lvgl/lv_mpy.o build/lvgl/lv_mpy.c

[amirgon]

Could you try branch fix/282? I changed mp_obj_type to pointer, I think it should be anyway.

[embeddedt]

Seems to have moved the problem to a different location. Progress?

build/lvgl/lv_mpy.c:15952:13: error: initializer element is not a compile-time constant
 15952 |     parent, mp_lv_obj_type.mp_obj_type,
       |             ^~~~~~~~~~~~~~~~~~~~~~~~~~
../../py/obj.h:783:250: note: expanded from macro 'MP_DEFINE_CONST_OBJ_TYPE'
  783 | #define MP_DEFINE_CONST_OBJ_TYPE(...) MP_DEFINE_CONST_OBJ_TYPE_EXPAND(MP_DEFINE_CONST_OBJ_TYPE_NARGS(__VA_ARGS__, _INV, 12, _INV, 11, _INV, 10, _INV, 9, _INV, 8, _INV, 7, _INV, 6, _INV, 5, _INV, 4, _INV, 3, _INV, 2, _INV, 1, _INV, 0)(mp_obj_type_t, __VA_ARGS__))
      |                                                                                                                                                                                                                                                          ^~~~~~~~~~~
../../py/obj.h:749:415: note: expanded from macro 'MP_DEFINE_CONST_OBJ_TYPE_NARGS_7'
  749 | #define MP_DEFINE_CONST_OBJ_TYPE_NARGS_7(_struct_type, _typename, _name, _flags, f1, v1, f2, v2, f3, v3, f4, v4, f5, v5, f6, v6, f7, v7) const _struct_type _typename = { .base = { &mp_type_type }, .name = _name, .flags = _flags, .slot_index_##f1 = 1, .slot_index_##f2 = 2, .slot_index_##f3 = 3, .slot_index_##f4 = 4, .slot_index_##f5 = 5, .slot_index_##f6 = 6, .slot_index_##f7 = 7, .slots = { v1, v2, v3, v4, v5, v6, v7, } }
      |                                                                                                                                                                                                                                                                                                                                                                                                                               ^~
../../py/obj.h:770:44: note: expanded from macro 'MP_DEFINE_CONST_OBJ_TYPE_EXPAND'
  770 | #define MP_DEFINE_CONST_OBJ_TYPE_EXPAND(x) x
      |                                            ^

STATIC MP_DEFINE_CONST_OBJ_TYPE(
    mp_lv_canvas_type_base,
    MP_QSTR_canvas,
    MP_TYPE_FLAG_NONE,
    print, canvas_print,
    make_new, canvas_make_new,
    binary_op, mp_lv_obj_binary_op,
    attr, call_parent_methods,
    buffer, mp_lv_obj_get_buffer,
    parent, mp_lv_obj_type.mp_obj_type, // <---- this is the line that errors
    locals_dict, &canvas_locals_dict
);

[amirgon]

Seems to have moved the problem to a different location. Progress?

Maybe...
I've updated the branch, could you try again?

[embeddedt]

Unfortunately looks about the same to me.

build/lvgl/lv_mpy.c:15429:34: error: initializer element is not a compile-time constant
 15429 |     { MP_ROM_QSTR(MP_QSTR_CTRL), MP_ROM_PTR(mp_lv_LV_BTNMATRIX_CTRL_type.mp_obj_type) },
       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../py/obj.h:348:23: note: expanded from macro 'MP_ROM_PTR'
  348 | #define MP_ROM_PTR(p) (p)
      |                       ^~~
build/lvgl/lv_mpy.c:15462:13: error: initializer element is not a compile-time constant
 15462 |     parent, mp_lv_obj_type.mp_obj_type,
       |             ^~~~~~~~~~~~~~~~~~~~~~~~~~
../../py/obj.h:783:250: note: expanded from macro 'MP_DEFINE_CONST_OBJ_TYPE'
  783 | #define MP_DEFINE_CONST_OBJ_TYPE(...) MP_DEFINE_CONST_OBJ_TYPE_EXPAND(MP_DEFINE_CONST_OBJ_TYPE_NARGS(__VA_ARGS__, _INV, 12, _INV, 11, _INV, 10, _INV, 9, _INV, 8, _INV, 7, _INV, 6, _INV, 5, _INV, 4, _INV, 3, _INV, 2, _INV, 1, _INV, 0)(mp_obj_type_t, __VA_ARGS__))
      |                                                                                                                                                                                                                                                          ^~~~~~~~~~~
../../py/obj.h:749:415: note: expanded from macro 'MP_DEFINE_CONST_OBJ_TYPE_NARGS_7'
  749 | #define MP_DEFINE_CONST_OBJ_TYPE_NARGS_7(_struct_type, _typename, _name, _flags, f1, v1, f2, v2, f3, v3, f4, v4, f5, v5, f6, v6, f7, v7) const _struct_type _typename = { .base = { &mp_type_type }, .name = _name, .flags = _flags, .slot_index_##f1 = 1, .slot_index_##f2 = 2, .slot_index_##f3 = 3, .slot_index_##f4 = 4, .slot_index_##f5 = 5, .slot_index_##f6 = 6, .slot_index_##f7 = 7, .slots = { v1, v2, v3, v4, v5, v6, v7, } }
      |                                                                                                                                                                                                                                                                                                                                                                                                                               ^~
../../py/obj.h:770:44: note: expanded from macro 'MP_DEFINE_CONST_OBJ_TYPE_EXPAND'
  770 | #define MP_DEFINE_CONST_OBJ_TYPE_EXPAND(x) x
      |                                            ^
build/lvgl/lv_mpy.c:15771:13: error: initializer element is not a compile-time constant
 15771 |     parent, mp_lv_obj_type.mp_obj_type,
       |             ^~~~~~~~~~~~~~~~~~~~~~~~~~

[amirgon]

Unfortunately looks about the same to me.

Forgot to push, sorry.... Try now?

[embeddedt]

Much better, now only the MP_ROM_PTR one remains.

build/lvgl/lv_mpy.c:12731:34: error: initializer element is not a compile-time constant
 12731 |     { MP_ROM_QSTR(MP_QSTR_FLAG), MP_ROM_PTR(mp_lv_LV_OBJ_FLAG_type.mp_obj_type) },
       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../py/obj.h:348:23: note: expanded from macro 'MP_ROM_PTR'
  348 | #define MP_ROM_PTR(p) (p)
      |                       ^~~

[amirgon]

Much better, now only the MP_ROM_PTR one remains.

Fixed now?

[embeddedt]

Seems to have carried on compiling now! Thank you!

[amirgon]

When it's all good - we can merge https://github.com/lvgl/lv_binding_micropython/pull/284