On 17-11-16 23:48, Julia Lawall wrote:
>
>
> On Thu, 17 Nov 2016, Arend Van Spriel wrote:
>
>> Not seen a response on the backports mailing list so subscribed to the
>> cocci mailing list and reposting it.
>
> Sorry to have missed seeing it.
No problem.
>>
>> Attached is a script I want to use to backport drivers. However, the
>> second (unnamed) rule matches for each occurence of 'struct
>> net_device_ops'. Is there a way to disable a rule after a desired amount
>> of matches (in my case once)?
>
> Here is a somewhat clunky solution:
>
> @initialize:python@
> @@
>
> first_ops = 0
>
> @r@
> identifier OPS;
> position p;
> @@
>
> struct net_device_ops OPS@p = { ... };
>
> @script:python depends on r@
> @@
>
> first_ops = 0
>
> @script:python@
> p << r.p;
> @@
>
> ln = int(p[0].line)
> if first_ops == 0 or ln < first_ops:
> first_ops = ln
>
> @script:python@
> p << r.p;
> @@
>
> ln = int(p[0].line)
> if not(first_ops == ln):
> cocci.include_match(False)
>
> @r1 exists@
> expression ndevexp, e1, e2;
> identifier func;
> @@
> func(...) {
> <+...
> - ndevexp->min_mtu = e1;
> - ndevexp->max_mtu = e2;
> ...+>
> }
>
> @r2@
> expression r1.e1,r1.e2;
> identifier r.OPS;
> @@
> + static int __change_mtu(struct net_device *ndev, int new_mtu)
> + {
> + if (new_mtu < e1 || new_mtu > e2)
> + return -EINVAL;
> + ndev->mtu = new_mtu;
> + }
> +
> struct net_device_ops OPS = {
> ...
> };
>
> @depends on r2@
> identifier OPS;
> @@
>
> struct net_device_ops OPS = {
> + .ndo_change_mtu = __change_mtu,
> ...
> };
>
> -------------------------
Big thanks. Have not tried it yet, but do you want me to add your
Signed-off-by given that you mostly solved the problem.
> Basically, the idea is to find the line number of the start of each
> net_device_ops structure. The first script:python rule initializes
> first_ops for the current file. The second one passes through the
> position information for each net_device_ops structure and finds the
> smallest line number. The third python rule discards all matches that
> don't have the name of the structure on the collected smallest line.
Yeah. Was wondering how to tackle that as I read in the documentation
that the order in which matches are processed is not predictable.
> Rule
> r1 then matches the two assignments, rule r2 puts the new function on top
> of the earliest detected structure (determined by the inherited value of
> OPS), and then the last rule added the field to the structure.
Understand. Thanks again.
> I noticed that there is a problem though when the structure is define
> within a function. Then the added function goes in that structure too.
> The affected file is: drivers/tty/n_gsm.c. Maybe you odn't want o
> backport that one?
It is not (yet) in the backports copy-list so we are good for now.
Regards,
Arend
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