Re: Keep local symbols of rump libraries

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Thu, Apr 13, 2017 at 12:22 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
> On Wed, Apr 12, 2017 at 6:58 PM, Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
>> On Wed, Apr 12, 2017 at 9:27 AM, Chuck Silvers <chuq%chuq.com@localhost> wrote:
>>> On Mon, Apr 10, 2017 at 07:22:45PM +0900, Ryota Ozaki wrote:
>>>> Hi,
>>>>
>>>> I'm using ATF tests running rump kernels (rump_server)
>>>> for development and debugging. When a rump kernel gets
>>>> panic, it dumps a core file from which we can obtain
>>>> a backtrace by using gdb.
>>>>
>>>> Unfortunately local symbols (i.e., static functions)
>>>> in a backtrace are unresolved because they are stripped
>>>> by the linker (and objdump). That makes debugging a bit
>>>> difficult.
>>>>
>>>> The patch introduces a compile option for rump kernels
>>>> called RUMP_KEEPSYMBOLS to keep such symbols:
>>>>   http://www.netbsd.org/~ozaki-r/rumplibs-keep-symbols.diff
>>>>
>>>> The option is disabled by default to not increase
>>>> the size of all rump libraries.
>>>>
>>>> I'm not so familiar with the NetBSD build system and
>>>> Makefiles, so the patch may be wrong or clumsy.
>>>>
>>>> Any comments?
>>>
>>> I've been meaning to ask about something similar to this
>>> but for everything in the build (libraries and commands)
>>> for the benefit of dtrace.  dtrace "ustack()" stack traces
>>> are similarly less useful without the static symbols.
>>>
>>> my patch for that was similar to yours, but I changed the
>>> "-Wl,-x" to "-Wl,-X" rather than removing the option entirely.
>>> for OBJCOPYLIBFLAGS I did what you did, though I suppose using "-X"
>>> there too would have been more consistent.
>>
>> Sure. Changing -x to -X works for me.
>>
>>>
>>> if we had an option for preserving static symbols for everything,
>>> would you still want a rump-library-specific option?
>>
>> If it's useful for other than rump libraries, having a new global
>> option would be adequate. I don't have an idea of the name though.
>
> http://www.netbsd.org/~ozaki-r/libs-keep-symbols.diff
>
> So this is a new patch that provides a global option named MKSTRIPSYM.
> (the name is suggested by paulg, thanks!)

The patch is updated; bsd.lua.mk also applies MKSTRIPSYM. Let me know
if the change is wrong.

Thanks,
  ozaki-r