Attribute for custom memset function

[Andrew Pinski]

On Mon, Sep 8, 2025 at 12:47 AM Chris Packham via Gcc <gcc@gcc.gnu.org> wrote:
>
> Hi GCC,
>
> For various reasons I find myself working with a few code bases that define
> their own wrappers for memset(). Unfortunately these wrappers defeat gccs
> ability to detect when the size of the pointer is passed instead of the
> size of the pointed to object.
>
> Is there any attribute I can set on the memset like functions that will let
> gcc know to perform the same kinds of checks as the standard memset
> function?

There is not one for this specific warning. The code currently does a
check on BUILT_IN_MEMSET in both the C and C++ front-ends.
The calloc warning is based on "alloc_size" attribute though.
So having a new attribute specifically for this kind of warning seems
like a good idea. Can you file a bugzilla to add one that specifies
the 2 arguments for memset ...

Thanks,
Andrew Pinski


>
> Thanks,
> Chris