Re: [cocci] Checking SmPL support for two special expressions

On Tue, 11 Nov 2025, Markus Elfring wrote:

> Hello,
>
> I constructed another SmPL script variant. It exported some data from
> selected function implementations which were found in header files.
> Data processing difficulties were detected then.
>
> See also:
> https://elixir.bootlin.com/linux/v6.18-rc5/source/include/drm/drm_crtc.h#L48-L55
>
> It seems that contents can usually be handled from such a file.
>
> Markus_Elfring@Sonne:…/Projekte/Linux/next-analyses> /usr/bin/spatch --parse-c include/drm/drm_crtc.h
> …
> nb good = 1344,  nb bad = 0 =========> 100.00% good or passed
>
>
> Two SmPL rules were generated accordingly.
> Unfortunately, I am wondering about the following information.
> Questionable test results (according to the software combination “Coccinelle 1.3.0”):
>
> A)
> @r26@
> expression val;
> @@
> -( uint64_t ) * ( ( uint64_t * ) & val )
> +I642U64(val)
>
> Markus_Elfring@Sonne:…/Projekte/Coccinelle/Probe> /usr/bin/spatch --parse-cocci drm_crtc-I642U64-20251111.cocci
> …
> minus: parse error:
>   File "drm_crtc-I642U64-20251111.cocci", line 4, column 31, charpos = 56
>   around = ')',
>   whole content = -( uint64_t ) * ( ( uint64_t * ) & val )
>
> B)
> @r27@
> expression val;
> @@
> -( int64_t ) * ( ( int64_t * ) & val )
> +U642I64(val)
>
> Markus_Elfring@Sonne:…/Projekte/Coccinelle/Probe> /usr/bin/spatch --parse-cocci drm_crtc-U642I64-20251111.cocci
> …
> minus: parse error:
>   File "drm_crtc-U642I64-20251111.cocci", line 4, column 29, charpos = 54
>   around = ')',
>   whole content = -( int64_t ) * ( ( int64_t * ) & val )
>
>
> Under which circumstances will such data processing become better supported?

Coccinelle doesn't know these types.  You have to declare them with
typedef.

julia