Re: gcc build with -O0 results in corrupted -debuginfo package

On Fri, 2014-04-25 at 14:03 -0400, Adam Jackson wrote: > On Fri, 2014-04-25 at 18:10 +0200, Kevin Kofler wrote: >> Petr Spacek wrote: >>> I'm going to reproduce and debug issue in named. Do you see any specific >>> reason why I should use -O2 for serious debugging/development sessions? >> >> IMHO, you should always debug with optimization enabled.

Kevin, have you ever debugged with -O2 ? It's more than reasonable to want -O0. At -O2 some code becomes really annoying to follow because gcc will optimize away way too much of it into registers (and gdb will not print you the values you need to see) or will make stepping a nightmare with gdb jumping in an out of the function as it gets inlined and then some stuff moved "out of the original function" and things like that. I've been more than once in gdb with -O2, it is *not* pretty, nor useful.

debug symbols at -O2 are mostly useful to get backtraces, but if you need to really step through with gdb in some complicated, highly optimizable code, often it does not cut it, you have to rebuild with -O0 to regain debuggability and sanity.