Re: gdb says EVERY argument or variable is optimized out (Re: gdb and fission scheme (gcc: -gsplit-dwarf, gnu ld gold :--gdb-index ))

On 2015/01/26 17:48, Andrew Burgess wrote:
> * ISHIKAWA,chiaki <[email protected]> [2015-01-19 12:00:21 +0900]:
>
>> However, for debugging particular class of bugs,
>> I really needed to print some values on the stack trace when a
>> breakpoint is hit, as well as local variables manually.
>> So I made sure that I passed -O instead of higher optimization.
>
> -O is not "no optimisation", do you get better debugging with -O0 ?

This might be it!
I will check and report next week.

>> In my case, disabling -gsplit-dwarf means a very long time (several
>> minutes) of I/O during linking process alone and this is unacceptable
>> overhead for interactive debugging after changing a single C++
>> source file.
>
> OK, but you could try it one time and see if it fixes your problem.
> That would narrow down where the bug is coming from....

I will try it once also as well as -O0 above and report back.

with -gsplit-dwarf and -O0
without -gsplit-dwarf and {-O,-O0}

[Oh wait, I got a better symbol handling the year before, and I think
I used -O instead of -O0. Well, let me try anyway afresh and report back.]

Thank you for the hints!

TIA

>
> Thanks,
> Andrew
>
>