For the sake of brevity I will provide a couple of simple data types and a snippet of Jinja to add to the default C templates. Given the following data type declarations:
stuff/InnerType.1.0.dsdl:
# InnerType.1.0
bool[<=32] some_bits
# Some bits.
@sealed
stuff/OuterType.1.0.dsdl:
# OuterType.1.0
stuff.InnerType.1.0 bits_here;
# Need some bits.
@sealed
If you modify the c/templates/definitions.j2 to add the following macro:
{% macro _count_things(t) %}
{%- set count = namespace(value=0) -%}
{%- for f in t.fields_except_padding %}
{%- if f.data_type is StructureType %}
{%- set count.value = count.value + (_count_things(f.data_type) | trim | int) %}
{%- elif f.data_type is ArrayType %}
{%- if f.data_type is VariableLengthArrayType %}
{#- add 2 for variable length arrays #}
{%- set count.value = count.value + 2 %}
{%- elif f.data_type is FixedLengthArrayType %}
{%- set count.value = count.value + 3 %}
{%- endif %}
{%- else %}
{%- set count.value = count.value + 1 %}
{%- endif %}
{%- endfor %}
{{ count.value }}
{% endmacro %}
And call it like so:
#define {{ ref }}_THING_COUNT_ ({{ _count_things(t) | trim | int }})
What you’ll see is that for InnerType, you see stuff_InnerType_1_0_THING_COUNT_ (2), which is exactly what you’d expect. However, for OuterType, you will see stuff_OuterType_1_0_THING_COUNT_ (3), implying that bits_here.data_type has a field which is FixedLengthArrayType.
Unfortunately, I don’t have any more information to run with than this, but I’d be happy to investigate or provide other information if possible.