How to create property rnas?

Archive Blender Development
3

I’ve tried to add a float property but it prints an error about pointer alignment, I have no idea of what I did wrong.

on rna_brush.c ive added the property definition with a copy paste, edit.

 ...
RNA_def_property_ui_text(prop, "Autosmooth", "Amount of smoothing to automatically apply to each stroke");
RNA_def_property_update(prop, 0, "rna_Brush_update");

prop = RNA_def_property(srna, "toporake_factor", PROP_FLOAT, PROP_FACTOR);
RNA_def_property_float_sdna(prop, NULL, "toporake_factor");
RNA_def_property_float_default(prop, 0);
RNA_def_property_range(prop, 0.0f, 1.0f);
RNA_def_property_ui_range(prop, 0.0f, 1.0f, 0.001, 3);
RNA_def_property_ui_text(prop, "Toporake", "Automatically align dyntopo to the brush movement direction");
RNA_def_property_update(prop, 0, "rna_Brush_update");

prop = RNA_def_property(srna, "stencil_pos", PROP_FLOAT, PROP_XYZ);
RNA_def_property_float_sdna(prop, NULL, "stencil_pos");
...
...

and on DNA_brush_types.c I added float definition.

float autosmooth_factor;

float toporake_factor;

float crease_pinch_factor;

but during compile it prints this error message:

4>Align pointer error in struct (len_native 8): Brush *gpencil_settings
4>Align pointer error in struct (len_64 8): Brush *gpencil_settings
4>Sizeerror 8 in struct: Brush (add 4 bytes)