Time for turning off gdb by default? Or worse...

[Ian Lepore]

On Tue, 2014-04-08 at 15:43 -0600, Warner Losh wrote:
> On Apr 8, 2014, at 3:24 PM, Steve Kargl <sgk at troutmask.apl.washington.edu> wrote:
> 
> > On Tue, Apr 08, 2014 at 02:34:35PM -0600, Warner Losh wrote:
> > 
> > (courtesy line wrap to something well below 80 characters)
> > 
> >> The gdb in the tree seems to be of very limited usefulness
> >> these days. It doesn?t seem to work on clang-enabled
> >> architectures w/o building -gdwarf-2, it doesn?t seem to work
> >> with threaded applications, and on some architectures it
> >> doesn?t seem to work at all (mips comes to mind, but it may
> >> have been the two binaries I tried).
> >> 
> > 
> > (patch removed)
> > 
> >> to the tree, which will turn gdb off by default.  It may make
> >> more sense to just remove it entirely, but I?m not sure I want
> >> to go there just yet in case there are things that I?m missing.
> >> I believe that the port will be adequate for all architectures
> >> we support, but haven?t tested this directly yet. I do know
> >> that on amd64, the port just worked, where the in-tree gdb
> >> was an epic fail.
> > 
> > I suppose the obvious questions are:
> > 
> > 1) Is lldb ready for prime time?
> 
> Doesn’t matter.
> 
> > 2) What effect does this have on kgdb?  Note, /sys/conf/NOTES contains
> 
> Unfortunately, kgdb isn’t available as a port, so that does matter. It is one thing arguing against this change.
> 
> > #makeoptions	DEBUG=-g		#Build kernel with gdb(1) debug symbols
> > 
> > Should this be updates to DEBUG=-gdwarf-2?
> 
> Nope. It should stay exactly as it is. We convert -g to -gdwarf-2 for those compilers that need it.

Only when building the kernel.  For userland we've got nothing.  gdb
aside, even addr2line doesn't work on userland binaries anymore.  It
used to be hard to do debugging for arm.  Now it's impossible.

-- Ian