scanner.py: add support for "original_type" attribute of "Argument" XML tag

[pdatkinson]

scanner.py: add support for "original_type" attribute of "Argument" XML tag. For array args this means avoiding losing the delcared width of the array and having its decl_type show as pointer_t.

Fall back on "type" (current default-no-matter-what) attribute when "original_type" is not present.

XML generated by pygccxml+CastXML:

Behaviour:

classes_obj                       = global_ns.classes()
class_im_looking_for              = [d for d in classes_obj.declarations if "class_im_looking_for" in d.name][0]
method_im_looking_for_declaration = [d for d in class_im_looking_for.declarations if d.name == "method_name"][0]
method_arguments                  = method_im_looking_for_declaration.arguments
argument                          = method_arguments[0]

# pre-PR this gives:
argument.decl_type.decl_string
Out[2]: '::my_namespace::my_type *'
pygccxml.declarations.type_traits.array_size(argument.decl_type)
#AssertionError: 
#> path/to/site-packages/pygccxml/declarations/type_traits.py(293)array_size()
#    291     nake_type = remove_reference(nake_type)
#    292     nake_type = remove_cv(nake_type)
#--> 293     assert isinstance(nake_type, cpptypes.array_t)
#    294     return nake_type.size

# post-PR this gives:
argument.decl_type.decl_string
Out[4]: '::my_namespace::my_type[1024]'
pygccxml.declarations.type_traits.array_size(argument.decl_type)
Out[5]: 1024

[pdatkinson]

Overwrote previous commit to avoid linter complaints.

[pdatkinson]

Overwrote previous commit to fix silly oversight where decl_type fallback assignment value was XML_AN_TYPE ("type" literal) and not the value in attrs mapped to by XML_AN_TYPE.

[iMichka]

Looks great. Please ignore the macos runner errors, these are pre-existing.

Do you think you could add a test for this?

Most of the tests are now in the tests folder (ran with pytest), and some legacy tests are in the unitest folder. Either one of these can be extended or a new one can be written.

[pdatkinson]

Overwrote previous commit to include tests/test_array_argument.py (left out of first commit of the pair - kind of important I guess 😋)

[pdatkinson]

Overwrote previous commit to avoid the stern gaze of the linter.

[iMichka]

Thanks for the test!

How quickly do you need this in a new release? I will probably do one before end of 2024, if you need the change in a release faster than that, I can do one next week.

[pdatkinson]

Thanks for the merge!

No rush re a release. I'm working off of a local copy currently and can continue to do so.

[iMichka]

@pdatkinson v2.6.0 is out and contains the change

[pdatkinson]

@iMichka awesome - thank you!