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SubjectRe: [PATCH 10/10] check pr_debug() arguments
On Fri,  8 Sep 2006 15:55:29 -0700 (PDT)
Zach Brown <zach.brown@oracle.com> wrote:

> check pr_debug() arguments
>
> When DEBUG isn't defined pr_debug() is defined away as an empty macro. By
> throwing away the arguments we allow completely incorrect code to build.
>
> Instead let's make it an empty inline which checks arguments and mark it so gcc
> can check the format specification.

Desirable.

> This results in a seemingly insignificant code size increase. A x86-64
> allyesconfig:
>
> text data bss dec hex filename
> 25354768 7191098 4854720 37400586 23ab00a vmlinux.before
> 25354945 7191138 4854720 37400803 23ab0e3 vmlinux

Which would indicate that we might have expressions-with-side-effects
inside pr_debug() statements somewhere, which is risky. I wonder where?

It looks like the version of gcc which you used is correctly discarding the
pr_debug() format string. gcc hasn't always done that, and there's a risk
of bloatiness on older gccs. I checked gcc-3.3.2/x86 and it does the right
thing, so...

btw, what's up with aio.c using a combination of pr_debug() and dprintk(),
and a combination of `#ifdef DEBUG' and `#if DEBUG > 1'? Confusing.


It would be nice to have a single way of doing developer-debug in-tree. We
have 182(!) different definitions of dprintk(). Please nobody cc me on that
discussion though ;)
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