Re: fstack options

[Andrew Cagney <cagney@redhat.com>]

Mark,

A two stage pass might work for an elf based backtrace as only the code 
addresses and address map need to be saved.  However, for a more 
detailed backtrace, involving variable values et.al. the debug info 
needs to be scanned during the first pass to determine what to save for 
that second pass.

Andrew

Mark Wielaard wrote:
> On Thu, 2007-06-14 at 13:51 -0400, Andrew Cagney wrote:
>   
>> fstack's, and its pre-cursors - gstack and pstack, first priority is 
>> speed - get in, get a backtrace, get out - and I think it is fair to 
>> assume that having to scan multi-megabytes of .debug info would run 
>> against that goal (fstack probably shouldn't look in .debug_line by 
>> default either).
>>
>> Perhaps an option << fstack -a >> to reverse the goal and display 
>> everything known about the function would address this.
>>     
>
> So would a 2 stage approach be an idea. fstack just gets the addresses
> on the stack, writes them out (or buffers them) and gets out. Then the
> result gets pushed through addr2line (or a frysk based alternative if
> you want) that pieces together the actual source lines from the
> addresses and the exe associated with the pid?
>
> Cheers,
>
> Mark
>