Re: backtrace changes current source location

[Andrew Cagney <cagney@gnu.org>]

Thanks!

Felix Lee wrote:
> Andrew Cagney <cagney@gnu.org>:
> 
>>Can you find out why selected sal is being corrupted, code shouldn't be 
>>modifying it.
> 
> 
> this is happening in stack.c:print_frame_info().  any time
> information about a frame is printed, sal is set to that frame's
> location.  the motivation for that change was an MI issue where
> sal didn't get set when it should be.
> 
> it seems reasonable to me to always set sal when a frame gets
> printed, but this is inconvenient in the case of backtraces.
> backtraces seem like an exception, rather than a flaw in the
> general strategy, which is why I chose to save/restore sal in
> backtrace.

Should:

(gdb) info frame 5

change things to frame 5's sal?

> my feeling is that sal is a user convenience for reducing typing,
> and programs talking to gdb should not depend on it being
> predictable, since it's easy for a program to specify precisely
> what source location they're interested in.  but I don't feel
> strongly about that.

Right.

MI and/or CLI should locally determine current-sal, and pass it down to 
print_frame_info.

> I'll submit a new patch with the changes
> you suggest.

I'm actually not yet suggesting anything yet :-).   I'm just trying to 
understand why two ends of GDB end up fighting over what the value of 
current-sal should be :-(

Lets get the testcase in.

Andrew