[alsa-devel] Kill snd_assert()

[Takashi Iwai]

Hi,

as some people already mentioned, we have a pretty ugly macro, snd_assert().
Actually, this macro is sometimes useful, but the implementation including
the code flow in arguments is really bad.

I tried to kill this, either the following way:

 - replace
	snd_assert(cond, flow...);
   with
	if (snd_BUG_ON(!cond))
		flow...;

 - use WARN_ON() if the check is needed essentially regardless of
   CONFIG_SND_DBEBUG value

 - remove snd_assert() for obviously unneeded code-paths

The new snd_BUG_ON() macro takes the condition, and works like
WARN_ON() if CONFIG_SND_DEBUG=y: prints the warning with stack trace, 
and returns the evaluated value.  When CONFIG_SND_DEBUG=n, the macro
returns always zero, so that the compiler will optimize out the
unreached flows.

Since snd_BUG_ON() takes the condition of a bug, it's a negative
condition against snd_assert().  It follows BUG_ON() and WARN_ON(),
and easier to understand, IMO.


The patches are found on topic/remove-assert branch of my git tree:

   git://git.kernel.org/pub/scm/linux/kernel/tiwai/sound-2.6.git

For gitweb,
   http://git.kernel.org/?p=linux/kernel/git/tiwai/sound-2.6.git;a=shortlog;h=topic/remove-assert

I haven't merged this topic yet.  If you have a big objection or a
better implementation idea, please let me know.


Takashi