Re: [Xenomai-core] [RFC] fix XENO_OPT_DEBUG bugs.

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Jan Kiszka wrote:
> Gilles Chanteperdrix wrote:
>> Jan Kiszka wrote:
>>> Gilles Chanteperdrix wrote:
>>>> Hi,
>>>>
>>>> I found some code which was referencing directly some
>>>> CONFIG_XENO_OPT_DEBUG_ variables with things like:
>>>>
>>>> #ifdef CONFIG_XENO_OPT_DEBUG_FOO
>>>>
>>>> This usage is incompatible with the pre-requisites of the assert.h
>>>> header that CONFIG_XENO_OPT_DEBUG_FOO should be defined at all times.
>>>> While grepping for CONFIG_XENO_OPT_DEBUG_, I found that we also have
>>>> many duplicates of construction like:
>>>> #ifndef CONFIG_XENO_OPT_DEBUG_FOO
>>>> #define CONFIG_XENO_OPT_DEBUG_FOO 0
>>>> #endif /* CONFIG_XENO_OPT_DEBUG_FOO */
>>>>
>>>> So, a patch follows which:
>>>> - replace the #ifdef with some #if XENO_DEBUG(FOO)
>>> Should probably come as a separate patch.
>> Come on, the patch is simple, one patch for this is enough.
> 
> One part is an obvious fix, the other a refactoring under discussion.
> 
>>>> - move all the initializations to assert.h
>>>>
>>>> This will make any reference to CONFIG_XENO_OPT_DEBUG_FOO outside of
>>>> assert.h suspicious, and easy to detect.
>>> How many duplicates did you find?
>> A lot, especially for CONFIG_XENO_OPT_DEBUG_NUCLEUS
> 
> That's because the CONFIG_XENO_OPT_DEBUG_NUCLEUS defines were misplaced.
> Besides that we had one CONFIG_XENO_OPT_DEBUG_QUEUE duplicate, but tons
> of proper users. I don't see such an immediate need.
> 
> When adding this kind of switching, it's till more handy to have things
> locally in your subsystem. That also makes reviewing easier when you
> only find changes in files that belong to a subsystem.

That is not the main point, the main point is that putting all these
defines in one files allow to detect easily direct references to the
symbols.

> 
>>> Generally, I'm more a fan of decentralized management here (e.g. this
>>> avoids needless patch conflicts in central files).
>> If we maintain the list in alphabetical order (which I have done), we 
>> reduce the likeliness for conflicts. The aim of doing this is also that 
>> I can check that the sources are clean with:
>>
>> find xenomai-2.5 ! -name 'assert.h' -name '*.[ch]' | xargs grep CONFIG_XENO_OPT_DEBUG_
>>
>> And that I can add this test to the automated build test.
>>
>> Note that forgetting to add a #define to the list yields an immediate
>> compilation error. So, the patch makes things completely safe.
> 
> What did you change to make this happen (for new users of XENO_DEBUG)?

Nothing. If you forget to add the define, and do not enable the debug
option (which everybody does most of the time), you get a compilation
error.

What I changed, however, is that the above find | grep allows
immediately to detect direct users of the symbols.

-- 
					    Gilles.