Re: [PATCH 0/4] varargs functions with __attributes__(())

Jeff King [off-list ref] writes:

On Sat, Jun 08, 2024 at 11:37:43AM -0700, Junio C Hamano wrote:

quoted

There are several varargs functions that take either NULL-terminated
list of parameters, or printf-like format followed by list of
parameters, that are not declared as such with __attributes__(()).

Adding such a missing attribute to trace2_region_enter_printf()
revealed that an existing call to it was trying to format a value of
type size_t using "%d", which is not such an excellent idea.  Other
functions that were lacking attributes fortunately did not have any
broken existing callers.

Great, I am happy to see these. I assume you found them all by grepping?

I wonder if there is a way to convince the compiler (or coccinelle) to
complain about any varargs function that does not have one of our
usual annotations. It's possible to have other conventions (e.g., an
"int" up front specifying the number of entries) but in practice I doubt
we would ever use one.

Still, I suspect the answer is probably "no", there is not an easy way
to do it.

I just went from grepping for fixed "...)" in *.[ch] files.  I do
admit I wished some form of automation, but didn't come up with one.

I was happy that the exercise found a real bug ;-)  I started it
only as a clean-up topic.