Support for parameterized GNU style attributes on C++ code.

[obra]

Hi folks.

My C++ codebase uses GNU attributes for code like

__attribute__ ((optimize(3))) void readMatrix(void)

Unfortunately, it looks like Sphinx doesn't support them.

Exception occurred:
  File "/usr/local/lib/python3.7/site-packages/sphinx/domains/cpp.py", line 6099, in _parse_type
    raise self._make_multi_error(prevErrors, header)
sphinx.util.cfamily.DefinitionError: Error when parsing function declaration.
If the function has no return type:
  Invalid C++ declaration: Parameterized GNU style attribute not yet supported. [error at 25]
    __attribute__ ((optimize(3))) void readMatrix(void)
    -------------------------^
If the function has a return type:
  Invalid C++ declaration: Parameterized GNU style attribute not yet supported. [error at 25]
    __attribute__ ((optimize(3))) void readMatrix(void)
    -------------------------^

I'm running Sphinx 3.1.1, though this functionality doesn't appear to have changed in 4.

I tried to get clever with the custom attribute support you offer, but can't seem to get that to work either.

cpp_id_attributes = ["aligned","packed","weak","always_inline","noinline","no-unroll-loops","__attribute__((optimize(3)))"]
cpp_paren_attributes = ["optimize","__aligned__","section","deprecated"]

Is there a right way to do this? I'd honestly be fine having the attributes stripped entirely for doc generation if there isn't another option.

Even though I'm bumping up against a sharp edge, I really appreciate Sphinx. Thanks so much for making a useful tool.

[jakobandersen]

I tried to get clever with the custom attribute support you offer, but can't seem to get that to work either.

Unfortunately, Sphinx is cleaver enough to recognize that it definitely is a GNU style attribute, so the custom entries are not even tried.

Is there a right way to do this?

Yes, upgrade to v3.2 once it has been released :-), and until then use the 3.x branch where I added the support.

[obra]

Awesome. Thank you so much!