Messages in this thread | | | Date | Sun, 20 Jul 2014 21:23:15 +0200 | From | Sam Ravnborg <> | Subject | Re: [PATCH 2/2] Kbuild: Add a option to enable dwarf4 |
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On Wed, Jul 16, 2014 at 01:16:12AM +0200, Andi Kleen wrote: > From: Andi Kleen <ak@linux.intel.com> > > I found that a lot of unresolvable variables when using gdb on the kernel > become resolvable when dwarf4 is enabled. So add a Kconfig flag to enable it. > > It definitely increases the debug information size, but on the other > hand this isn't so bad when debug fusion is used.
Would it not make sense to try to enable degug info like this: First try -gdwarf-4 If this fails try -gdwarf-3 If this fails try -gdwarf-2 And if this also fails fallback to -g
We could then us a Kconfig option to enable the highest debug level - where 4 for now is the highest. On the other hand if most people have revent utils then they all have -gdwarf-4 supported and then it is no big deal.
Sam
> > Signed-off-by: Andi Kleen <ak@linux.intel.com> > --- > Makefile | 3 +++ > lib/Kconfig.debug | 9 +++++++++ > 2 files changed, 12 insertions(+) > > diff --git a/Makefile b/Makefile > index 953659e..9c4080b 100644 > --- a/Makefile > +++ b/Makefile > @@ -690,6 +690,9 @@ KBUILD_CFLAGS += -g > KBUILD_AFLAGS += -Wa,-gdwarf-2 > endif > endif > +ifdef CONFIG_DEBUG_INFO_DWARF4 > +KBUILD_CFLAGS += -gdwarf-4 > +endif Should we sue $(call cc-option ...) here as not all gcc's supports this today?
Sam
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