[Cocci] metavariables for initialize/finalize

[Cocci] metavariables for initialize/finalize

[Julia Lawall]

SmPL allows defining initialize and finalize script rules that are rnu 
before and after the treatment of any files, repectively.  They are useful 
for managing counters, hash tables, etc. and for defining frequently used 
script functions.

At the moment, they do not allow the declaration of any metavariables.  In 
particular the syntax is, eg:

@initialize:python@

python code

without the second @@ as found in all other kinds of rules.

The problem is that this makes it impossible to refer to command line 
arguments (ie virtual identifiers) in the initialize and finalize rules, 
which can be useful.

One possibility would be to add metavariable declarations, as found 
elsewhere.  This would mean adding @@ to any existing semantic patches 
that contain initialize and finalize rules.

Another option would be to make the second @@ optional.  This preserves 
backward compatability, but it makes the language more complex, and it is 
not so easy to implement, because normally I don't parse the script code.

A third option would be to make it possible to refer to eg virtual.xyz 
directly in the script code, regardless of the language.  These would then 
get replaced by their values from the command line before passing the code 
to the interpreter of the script language.

What do you think?  I prefer the fist option, because the language remains 
(indeed, becomes more) uniform.  But the backward compatability is an 
issue.  On the other hand, maybe most people don't use initialize and 
finalize rules?

Thanks,
julia

[Cocci] Improvements for Coccinelle API

[SF Markus Elfring]

> A third option would be to make it possible to refer to eg virtual.xyz
> directly in the script code, regardless of the language.

I would prefer such an approach. I'd like to suggest that a specific 
function will return an object which provides access to a general 
application programming interface for Coccinelle.

Regards,
Markus

[Cocci] Improvements for Coccinelle API

[Nicolas Palix]

On Fri, Jun 21, 2013 at 9:29 AM, SF Markus Elfring
<elfring@users.sourceforge.net> wrote:
>
>> A third option would be to make it possible to refer to eg virtual.xyz
>> directly in the script code, regardless of the language.
>
>
> I would prefer such an approach.

For me, it is the worst of the three options.
Are you going to implement it
and to maintain it in the long term ?


> I'd like to suggest that a specific
> function will return an object which provides access to a general
> application programming interface for Coccinelle.

We already have that...

>
> Regards,
> Markus
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--
Nicolas Palix
Tel: +33 4 76 51 46 27
http://membres-liglab.imag.fr/palix/