[cocci] [PATCH v3 2/6] coccinelle: misc: Add field_modify script

[Julia Lawall]

On Mon, 19 May 2025, Luo Jie wrote:

>
>
> On 4/24/2025 12:35 AM, Markus Elfring wrote:
> > …
> > > > -reg &= ~mask;
> > > > -reg |= FIELD_PREP
> > > > +       FIELD_MODIFY
> > > >                     (mask,
> > > > +                  &reg,
> > > >                      val
> > > >                     );
> > …
> > > With this code variant, there is no space prior to &reg, here is the
> > > example code changes generated by the SmPL code as below, is this
> > > expected?
> > …
> > > +++ b/drivers/phy/starfive/phy-jh7110-dphy-tx.c
> > > @@ -244,8 +244,7 @@ static int stf_dphy_configure(struct phy
> > >          i = stf_dphy_get_config_index(bitrate);
> > >
> > >          tmp = readl(dphy->topsys + STF_DPHY_APBIFSAIF_SYSCFG(100));
> > > -       tmp &= ~STF_DPHY_REFCLK_IN_SEL;
> > > -       tmp |= FIELD_PREP(STF_DPHY_REFCLK_IN_SEL, STF_DPHY_REFCLK_12M);
> > > +       FIELD_MODIFY(STF_DPHY_REFCLK_IN_SEL,&tmp, STF_DPHY_REFCLK_12M);
> > >          writel(tmp, dphy->topsys + STF_DPHY_APBIFSAIF_SYSCFG(100));
> >
> > The Coccinelle software is still evolving somehow.
> > Thus your test result can trigger further development considerations.
> > I hope that clarifications and corresponding improvements can be achieved
> > also according to such source code layout concerns.
> >
> > Regards,
> > Markus
>
> OK, understand. I will keep the original patch as below for now, as we
> need to ensure the script generates code with the expected style.
> +- reg &= ~mask;
> +- reg |= FIELD_PREP(mask, val);
> ++ FIELD_MODIFY(mask, &reg, val);
>
> In addition, below case is filed to request this improvement on the
> coccinelle project.
> https://github.com/coccinelle/coccinelle/issues/397

Thanks for the report.

julia


>
> Thanks.
>