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[PATCH 07/11] mfd: Drop unnecessary static

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  [PATCH 07/11] mfd: Drop unnecessary static Julia Lawall <Julia.Lawall@lip6.fr> - 2017-07-15 22:40 +0200
    Re: [PATCH 07/11] mfd: Drop unnecessary static Mark D Rustad <mrustad@gmail.com> - 2017-07-15 23:00 +0200
      Re: [PATCH 07/11] mfd: Drop unnecessary static Julia Lawall <julia.lawall@lip6.fr> - 2017-07-15 23:00 +0200

#1687994 — [PATCH 07/11] mfd: Drop unnecessary static

Drop static on a local variable, when the variable is initialized before
any possible use.  Thus, the static has no benefit.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@bad exists@
position p;
identifier x;
type T;
@@
static T x@p;
...
x = <+...x...+>

@@
identifier x;
expression e;
type T;
position p != bad.p;
@@
-static
 T x@p;
 ... when != x
     when strict
?x = e;
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
These patches are all independent of each other.

 drivers/mfd/twl4030-irq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -u -p a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c
--- a/drivers/mfd/twl4030-irq.c
+++ b/drivers/mfd/twl4030-irq.c
@@ -685,7 +685,7 @@ int twl4030_sih_setup(struct device *dev
 
 int twl4030_init_irq(struct device *dev, int irq_num)
 {
-	static struct irq_chip	twl4030_irq_chip;
+	struct irq_chip		twl4030_irq_chip;
 	int			status, i;
 	int			irq_base, irq_end, nr_irqs;
 	struct			device_node *node = dev->of_node;

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#1688005

[Multipart message — attachments visible in raw view] — view raw

> On Jul 15, 2017, at 1:07 PM, Julia Lawall <Julia.Lawall@lip6.fr> wrote:
> 
> Drop static on a local variable, when the variable is initialized before
> any possible use.  Thus, the static has no benefit.

I think in this case the use relies on the structure continuing to exist, so a stack object is not an acceptable substitute. Just because it is initialized doesn't mean that it doesn't need a persistent lifetime.

> The semantic patch that fixes this problem is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @bad exists@
> position p;
> identifier x;
> type T;
> @@
> static T x@p;
> ...
> x = <+...x...+>
> 
> @@
> identifier x;
> expression e;
> type T;
> position p != bad.p;
> @@
> -static
> T x@p;
> ... when != x
>     when strict
> ?x = e;
> // </smpl>
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> 
> ---
> These patches are all independent of each other.
> 
> drivers/mfd/twl4030-irq.c |    2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff -u -p a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c
> --- a/drivers/mfd/twl4030-irq.c
> +++ b/drivers/mfd/twl4030-irq.c
> @@ -685,7 +685,7 @@ int twl4030_sih_setup(struct device *dev
> 
> int twl4030_init_irq(struct device *dev, int irq_num)
> {
> -	static struct irq_chip	twl4030_irq_chip;
> +	struct irq_chip		twl4030_irq_chip;
> 	int			status, i;
> 	int			irq_base, irq_end, nr_irqs;
> 	struct			device_node *node = dev->of_node;

--
Mark Rustad, MRustad@gmail.com

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#1688006

On Sat, 15 Jul 2017, Mark D Rustad wrote:

> > On Jul 15, 2017, at 1:07 PM, Julia Lawall <Julia.Lawall@lip6.fr> wrote:
> >
> > Drop static on a local variable, when the variable is initialized before
> > any possible use.  Thus, the static has no benefit.
>
> I think in this case the use relies on the structure continuing to exist, so a stack object is not an acceptable substitute. Just because it is initialized doesn't mean that it doesn't need a persistent lifetime.

OK, I see.  Thanks for the feedback.  I'll extend the rule to ensure that
the address of the variable is not taken.  Ignore this patch in any case.

julia

>
> > The semantic patch that fixes this problem is as follows:
> > (http://coccinelle.lip6.fr/)
> >
> > // <smpl>
> > @bad exists@
> > position p;
> > identifier x;
> > type T;
> > @@
> > static T x@p;
> > ...
> > x = <+...x...+>
> >
> > @@
> > identifier x;
> > expression e;
> > type T;
> > position p != bad.p;
> > @@
> > -static
> > T x@p;
> > ... when != x
> >     when strict
> > ?x = e;
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> >
> > ---
> > These patches are all independent of each other.
> >
> > drivers/mfd/twl4030-irq.c |    2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff -u -p a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c
> > --- a/drivers/mfd/twl4030-irq.c
> > +++ b/drivers/mfd/twl4030-irq.c
> > @@ -685,7 +685,7 @@ int twl4030_sih_setup(struct device *dev
> >
> > int twl4030_init_irq(struct device *dev, int irq_num)
> > {
> > -	static struct irq_chip	twl4030_irq_chip;
> > +	struct irq_chip		twl4030_irq_chip;
> > 	int			status, i;
> > 	int			irq_base, irq_end, nr_irqs;
> > 	struct			device_node *node = dev->of_node;
>
> --
> Mark Rustad, MRustad@gmail.com
>
>

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