Re: [RFC v1 14/25] genirq: Kill the first parameter 'irq' of irq_flow_handler_t

Thomas Gleixner
2015-06-24T21:12:09Z

On Sat, 13 Jun 2015, Julia Lawall wrote:
> On Sat, 13 Jun 2015, Thomas Gleixner wrote:
>
> > On Sat, 13 Jun 2015, Julia Lawall wrote:
> >
> > > The following are the cases that require some manual attention, either
> > > because the handler is a local variable or because it is some other kind
> > > of expression.
> >
> > yep, found it in the logs already and found a missing search expression:
> >
> > |
> > gpiochip_set_chained_irqchip@p(e1,e2,e3,\(lih\|ih\|eh\))
> >
> > This is really impressive work!!!!
>
> Thanks :)
>
> I'll add the above pattern, but I guess you already have the results for
> that case.

Yes.

I did some more experiments and analyzed all functions which have the
signature

[static] void f(T irq, struct irq_desc *desc)

where T is either 'unsigned int' or 'u32'

That throws up a handful of false positives, but those are functions
which are called from a real handler function, so we want to look at
those anyway.

Now where my cocci foo ends is when I try to match both types in the
same rule, i.e.

@ fun exists @
identifier hf,irq,desc;
typedef u32;
@@

(
void hf(unsigned irq, struct irq_desc *desc) { ... }
|
void hf(u32 irq, struct irq_desc *desc) { ... }
)

results in:
Fatal error: exception Failure("minus: parse error:
= File "../cocci/find-pot-handler.cocci", line 7, column 5, charpos = 63
around = 'hf', whole content = void hf(unsigned irq, struct irq_desc *desc) { ... }
")

I tried a couple of other variants, but finally gave up and ran a
cocci script first which does s/u32/unsigned/ on those functions, but
of course because I'm lazy I wanted to do everything in one go. :)

Aside of that the ruleset you gave me works nicely except for that
part:

// no uses of the first parameter before the assignment
@@
identifier fun.hf,irq;
expression e;
type T;
fresh identifier firq = "__" ## irq;
position r.p,p1 != {s.p1,s1.p1};
@@

hf(T@p
- irq
+ firq
,...) {
... when != irq
when strict
? irq@p1 = e
... when any
}

That lacks a:

+ unsigned int irq;

and therefor missed to add the local variable 'unsigned int irq' in
case the parameter is only used for local storage.

That was simple enough to fix even for me :)

Thanks,

tglx