Re: [RFA][PR 16361] Add warnings for NULL pointer dereferences and such

[Florian Weimer <fweimer at redhat dot com>]

On 01/27/2014 08:09 PM, Jeff Law wrote:

> +		      if (dereference)
> +			warning_at ((gimple_location (use_stmt)
> +				     ? gimple_location (use_stmt)
> +				     : gimple_phi_arg_location (phi, i)),
> +				    OPT_Wnull_dereference,
> +				    "Potential NULL pointer dereference");

I think warnings should start with a small letter (unless the first word 
is capitalized for other reasons).  Two more instances follow.

Instead of "Potential invalid NULL argument or return value", "potential 
NULL value used in non-NULL context" would be clearer.  It would be 
really nice if you could add a note that points to the declaration of 
non-NULL-ness for the context.

After the change, the third argument to infer_nonnull_range seems always 
true, including the call in tre-vrp.c:infer_value_range, so there's a 
minor cleanup opportunity.

Looking at infer_nonnull_range, there's an undocumented interaction with 
-fdelete-null-pointer-checks.

--
Florian Weimer / Red Hat Product Security Team