PERFORCE change 48556 for review

[Poul-Henning Kamp]

In message <200403100801.i2A810eC071863 at repoman.freebsd.org>, Marcel Moolenaar 
writes:
>http://perforce.freebsd.org/chv.cgi?CH=48556
>
>Change 48556 by marcel at marcel_nfs on 2004/03/10 00:00:12
>
>	Revamp the kernel debugger support. There's a non-optional
>	front-end which constitutes the interface. Behind it are
>	the debugger back-ends. The back-ends, currently only DDB
>	and GDB, are optional and selectable at runtime.
>	
>	This commit replaces Debugger() and backtrace() references
>	with kdb_enter() and kdb_backtrace() respectively. Where
>	appropriate, <sys/kdb.h> is included.
>	
>	Note that most #ifdef DDB instances have to be replaced
>	with #ifdef DEBUG, because DDB is specific to a single
>	back-end, not to having debugging support in general. A
>	new option, GDB, has been added to add support for gdb.
>	This has to be worked-out still.

#ifdef DEBUG is a singulary bad choice since much code have private
use of that macro.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.