Re: [RFC] Clarification for “undefined behaviour”?

[Dan Carpenter]

On Wed, Mar 05, 2025 at 09:40:43AM +0100, Markus Elfring wrote:
> >>> The address of a data structure member was determined before
> >>> a corresponding null pointer check in the implementation of
> >>> the functions “dpu_hw_pp_enable_te” and “dpu_hw_pp_get_vsync_info”.
> >>>
> >>> Thus avoid the risk for undefined behaviour by removing extra
> >>> initialisations for the variable “c” (also because it was already
> >>> reassigned with the same value behind this pointer check).
> > There is no undefined behavior here.
> 
> Is there a need to improve the wording precision?
> 
> There are words which denote a special meaning according to aspects of
> the programming language “C”.
> https://en.cppreference.com/w/c/language/behavior
> 
> Dereferences of null pointers are treated in special ways.

This not a dereference.  It's just pointer math.

regards,
dan carpenter