Help w/ gdb

D.J. Barrow barrow_dj at yahoo.com
Mon Jan 17 07:41:13 EST 2000


It helps gdb a lot not to compile with optimisation.
e.g. compiling -g -O2 on powerpc stops gcc copying
parameters passed in registers onto the stack
to aid debugging, this results in stack traces &
viewing passed in parameters frequently being rubbish.

Mind you in a project as large as mosizza there may be
inline functions which gcc may refuse to compile
without optimisation.
In short if you can compile for debugging without
using -O2 do so or at least try to compile all the
code
of intrest without the -O2 flag.


--- Kevin Buettner <kev at primenet.com> wrote:
> 
> On Jan 15, 11:12pm, Sean Chitwood wrote:
> 
> > I periodically ask this question here because I
> have never found a
> > more appropriate audience or satisfactory answer.
> > 
> > I am attempting to help w/ the mozilla project,
> but I am having
> > little success due to the following problem.  When
> I attempt to
> > debug an assert/crash as I bring up the stack
> trace I notice that
> > some of the frames point only to the ending curly
> brace of a
> > function (Not always the one it says is being
> debugged).  I cannot
> > examine variables, or learn anything else
> productive about the
> > situation.  I realize I am not familiar w/ gdb, I
> am primarily
> > familiar w/ windows GUI based debuggers, so I
> figure I am missing a
> > configuration setting, but for the life of me I
> can't figure out
> > what it is.  I do know that I am keeping the
> source and binary files
> > synced, so that shouldn't be it.  It seems to load
> the symbols
> > correctly (no complaining about missing symbols),
> butother than that
> > I seem to be clueless.
> 
> I think this is a bug in either the linker or in gdb
> itself.  (If it's
> the bug I'm thinking of, the bug is actually in the
> linker, but is
> more easily worked around in gdb.) Get the gdb
> sources and take a look
> at config/powerpc/tm-linux.h.  Now search for the
> line
> 
> #define SOFUN_ADDRESS_MAYBE_MISSING
> 
> Is it there?  (I'm guessing not.) Try adding the
> above line to
> tm-linux.h and then rebuild gdb.
> 
> Let me know if it fixes your problem.
> 
> Thanks,
> 
> Kevin
> 
> -- 
> Kevin Buettner
> kev at primenet.com, kevinb at cygnus.com
> 
> 

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