Re: GDB record target 0.0.1 for GDB-6.6 release (It make GDB support Reversible Debugging)

["Robert Bu" <robert.bu@gmail.com>]

> ------------------------------------------------------------------------
>
> 主题:
> Re: GDB record target 0.0.1 for GDB-6.6 release (It make GDB support
> Reversible Debugging)
> 发件人:
> Daniel Jacobowitz <drow@false.org>
> 日期:
> Fri, 10 Aug 2007 14:18:17 -0400
> 收件人:
> teawater <teawater@gmail.com>
>
> 收件人:
> teawater <teawater@gmail.com>
> 抄送:
> gdb@sources.redhat.com
>
>
> On Fri, Aug 10, 2007 at 05:31:51PM +0800, teawater wrote:
>> Hi All,
>>
>> The attachment is a patch for the GDB-6.6 that will add two commands
>> ("record" and "reverse") and a new target "record" to the GDB-6.6.
>>
>> The command "record" can record running message such as the program pc
>> register value and some frame message to a record file that default
>> name is "now.rec".
>>
>> The target "record" can open this record file and debug the program.
>> And if the current target is the "record", you can use command
>> "reverse" set debug to the reverse debug mode. If you set GDB to the
>> reverse debug mode. The program will reverse run. Most of GDB command
>> such as "step", "next" and "breakpoint" can be use in this mode.
>>
>> Maybe the record function can make GDB debug real time program more
>> easy than before because you can record all the running message when
>> the real time program cannot be interrupt and debug it after it was
>> running.
>
> I took a look at your patch.  The record command single steps the
> program until it exits, right?  That will not be very useful for real
> time programs, because it will be extraordinarily slow the first time.
>
> You might want to take a look at my paper in this year's GCC Summit
> proceedings:
>
>   http://gcc.gnu.org/wiki/HomePage?action=AttachFile&do=get&target=GCC2007-Proceedings.pdf
>
> We'll be publishing the code for "reverse-step" using qemu soon.

The qemu method is appropriate for native-debugging. However, it's
really not possible for remote-debugging, in which case the mothod of
this patch may apply if we can put up with the poor performance.

> We're not trying to hold on to it, especially - just haven't found the
> time yet to submit it.  This is basically similar to what you've done,
> except higher performance.
>
> Actually, your work also reminds me of Amber:
>   http://weblogs.mozillazine.org/roc/archives/2006/12/more_about_ambe.html
>
>
>

robert