[FFmpeg-devel] Moving if(constant expression) to preprocessor?

[Måns Rullgård]

Luca Barbato <lu_zero at gentoo.org> writes:

> On 09/20/2010 03:31 PM, M?ns Rullg?rd wrote:
>>> step backward, 
>> 
>> Huh?
>
> gdb) help rs
> Step program backward until it reaches the beginning of another source line.
> Argument N means do this N times (or till program stops for another reason).
> (gdb) help rsi
> Step backward exactly one instruction.
> Argument N means do this N times (or till program stops for another reason).
> (gdb) help rn
> Step program backward, proceeding through subroutine calls.
> Like the "reverse-step" command as long as subroutine calls do not happen;
> when they do, the call is treated as one instruction.
> Argument N means do this N times (or till program stops for another reason).
> (gdb) help rni
> Step backward one instruction, but proceed through called subroutines.
> Argument N means do this N times (or till program stops for another reason).

Does this stuff actually work in a usable manner?  Doesn't it require
(slow) tracing of the execution to record the state after each instruction?

>>> if it fails that it is not only not wonderfull but not even average
>
> reverse debugging is implemented elsewhere? For elf? Remote debugging?
> online evaluation/call?
>
> gdb is quite good IMHO.

gdb is reasonably good.  It has lots of nice features, although it can
be a bit annoying at times.  It is of course difficult to make a tool
that is easy to use in all situation, especially one so featureful as
gdb.  On the whole, I think it strikes a pretty good balance.

-- 
M?ns Rullg?rd
mans at mansr.com