Re: [PATCH 06/11] irqchip: mips-cpu: Drop unnecessary static

From: Mark D Rustad
Date: Sun Jul 16 2017 - 02:05:17 EST


> On Jul 15, 2017, at 1:59 PM, Julia Lawall <julia.lawall@xxxxxxx> wrote:
>
> On Sat, 15 Jul 2017, Mark D Rustad wrote:
>
>>
>>> On Jul 15, 2017, at 1:07 PM, Julia Lawall <Julia.Lawall@xxxxxxx> wrote:
>>>
>>> Drop static on a local variable, when the variable is initialized before
>>> any possible use. Thus, the static has no benefit.
>>
>> I think this is in error like the other one. I believe that the irq_chip structure needs a persistent lifetime.
>
> I'm not following in this case. chip is a pointer to a structure, not a
> structure. Its address is not taken. irq_set_chip_and_handler that uses
> it below is a fnuction, so it just gets the value.
>
> julia

Sorry. My mistake. I didn't look quite hard enough at this one.

>>
>>> 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@xxxxxxx>
>>>
>>> ---
>>> These patches are all independent of each other.
>>>
>>> drivers/irqchip/irq-mips-cpu.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff -u -p a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c
>>> --- a/drivers/irqchip/irq-mips-cpu.c
>>> +++ b/drivers/irqchip/irq-mips-cpu.c
>>> @@ -154,7 +154,7 @@ asmlinkage void __weak plat_irq_dispatch
>>> static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq,
>>> irq_hw_number_t hw)
>>> {
>>> - static struct irq_chip *chip;
>>> + struct irq_chip *chip;
>>>
>>> if (hw < 2 && cpu_has_mipsmt) {
>>> /* Software interrupts are used for MT/CMT IPI */
>>>
>>
>> --
>> Mark Rustad, MRustad@xxxxxxxxx

--
Mark Rustad, MRustad@xxxxxxxxx

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