Re: [PATCH] coccinelle: if(ret)return ret; return ret; semantic patch

From: Greg Dietsche
Date: Tue Jun 07 2011 - 11:48:04 EST

Hi Julia,

On 06/05/2011 11:55 PM, Julia Lawall wrote:
Thanks. I tried this too, but I wasn't sure about the results. The
question is why stop here.
very interesting! Honestly I hadn't thought much further than what you see in my semantic patch. I'd noticed piece of code in the iwlegacy driver and wondered what'd happen if I taught myself a little bit about cocci :)
For example, there are IS_ERR calls that one
could consider as well. Or ret< 0. Or why not just:

expression ret;

- if (...) return ret;
return ret;

Although there might be function calls that one doesn't want to touch, so:

identifier f != IS_ERR;
expression ret;
statement S;

if (<+...f(...)...+>) S
- if (...) return ret;
return ret;


There seem to be many variations on the theme to consider... though hopefully the compiler optimizes most of these out... For example, in sound/soc/codecs/wm8940.c, Jonathan Cameron pointed some code out to me that looks like this:

if (ret)
goto error_ret;

return ret;

As an aside, I added a feature to the script for myself so that I can for example write 'make coccicheck M=drivers/net/wireless/' for example to focus in on that directory and just run the checks there... I can submit a patch for this... though I was wondering if there is already a way to do this and I just missed it. The thought was to make it work the same way you'd build a module.


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