[maemo-developers] Help debugging segfaults

From: Eero Tamminen eero.tamminen at nokia.com
Date: Tue Feb 27 13:31:52 EET 2007

ext Simon Pickering wrote:
>> The reason is that without either debug symbols or 
>> framepointer Gdb doesn't know how many args to skip when 
>> unwinding the stack. Even the first function it shows is 
>> often wrong, because without debug symbols Gdb can try to 
>> match it only to the nearest _exported_ function and the 
>> function might have been a static (non-exported) one.
> Thanks for the explanation. I did compile the icas binary with -g and
> -fno-omit-frame-pointer (and it's unstripped), so presumably this means that gdb
> should know which function in the icas binary has called the failed chain of
> functions?
> Strange that icas is never mentioned, or perhaps it's just because the function
> chain is too long? I'll try compiling libgiac with -g and
> -fno-omit-frame-pointer

Actually you need just either of these. -fno-omit-frame-pointer can have
small adverse effect on performance if the code is calling a lot of
small functions.

If you use "-g", in the debian/rules file you can ask dh_strip to
separate the debug symbols to a separate debian package from the actual
binaries, so that the binary sizes are not affected (full debug
information can take more disk than the stripped binary size).

> (I don't think I really want to try re-compiling gcc
> atm) and see whether I can narrow the error down.

	- Eero

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