Weirdness in parsing cpp macros

[Jani Nikula]

On Wed, 20 Mar 2024, Julia Lawall <julia.lawall at inria.fr> wrote:
> On Wed, 20 Mar 2024, Jani Nikula wrote:
>> Okay, I have another one wrt macros. :)
>>
>> I'm trying to add a completely new variadic macro, but it fails at
>> "...". I've tried all sorts of things, but can't seem to be able to add
>> a literal "...".
>>
>> I've tested that my cocci patch works with x's:
>>
>> + #define fn(p, xxx) foo(__VA_ARGS__)
>>
>> but when I try to make it actually variadic like:
>>
>> + #define fn(p, ...) foo(__VA_ARGS__)
>>
>> it gives me error. Is there a way to escape? Even tried to use a fresh
>> identifier vararg = "..."; but cocci made them unique with numbering
>> "...0" and "...1" etc.
>
> Put 6 dots.  It's silly, but ... is a Coccinelle thing, so we had to use
> something else.

I've tried, but it doesn't seem to work in the + side:

plus: parse error: 
  File "/tmp/tmp.clvvc812Qe", line 20, column 2, charpos = 254
  around = '#define fn(',
  whole content = + #define fn(p, ......) __fn(__to_intel_display(p), __VA_ARGS__)

BR,
Jani.


-- 
Jani Nikula, Intel