[Cocci] minus: parse error:

[Julia Lawall]

On Fri, 24 Sep 2010, Greg McGary wrote:

>  Yes, the two-rule approach works--that's what I started with.  The ioctl_ref rule
> is the anchor for a series of six follow-on rules that apply transformations to
> ioctl-func decls.   If I have two rules, then I need to replicate the six follow-on
> rules with trivial modifications, one for each of unlocked_ioctl and compat_ioctl.
> The unified rule using (...|...) is highly desirable to avoid duplication for sake
> of development and maintenance.

Undoubtedly, it would be better to have disjunctions in this case as well.  
Without that there is a slightly convoluted way that you can avoid 
duplicating all of the rest of the rules:

@ ioctl_ref @
identifier fops_id;
identifier ioctl_id;
identifier I;
position p;
@@
struct file_operations fops_id  = {
   .I = ioctl_id at p,
};

@ 

@ ui @
identifier ioctl_ref.fops_id;
position ioctl_ref.p;
@@
struct file_operations fops_id  = {
   .unlocked_ioctl = ioctl_id at p,
};

@ ci @
identifier ioctl_ref.fops_id;
position ioctl_ref.p;
@@
struct file_operations fops_id  = {
   .compat_ioctl = ioctl_id at p,
};

@depends on ui || ci@
position ioctl_ref.p;
@@

...

In the last rule, you can do what you like with the structure, and if you 
put @p on ioctl_id then you will be touching one of the desired 
initializations.

A weak point of this strategy, though is that you can't inherit position 
variables over transformation rules.  So you can only have one 
transformation rule at the end.

julia