Some questions

Thu Jul 12 04:48:00 GMT 2001

Hi,
On Thu, Jul 12, 2001 at 10:21:37AM +0200, Martin Kahlert wrote:
>> Another strange thing is this:
> In the past i found some errors by running my prog with Electric Fence,
> but now, that doesn't work any more: It seems to loop forever.
> [...]
> The uppermost part is
> (gdb) where
> #0 0x4016db39 in _Jv_IsAssignableFrom(java::lang::Class*, java::lang::Class*)
> (target=0x83fb9a0, source=0x8604fb8) at ../../../libjava/java/lang/natClass.cc:958
> #1 0x4016dc0a in _Jv_IsInstanceOf (obj=0x861efe0, cl=0x83fb9a0) at ../../../libjava/java/lang/natClass.cc:993
> #2 0x4015d81e in __gcj_personality_v0 (version=1, actions=1,
> exception_class=5138137972373280321, ue_header=0x8738320,
> context=0xbf78299c) at ../../../libjava/exception.cc:348
> #3 0x4002734b in _Unwind_RaiseException (exc=0x8738320) at ../../gcc/unwind-dw2.c:981
> #4 0x4015d169 in _Jv_Throw (value=0x861efe0) at ../../../libjava/exception.cc:104
> #5 0x40153624 in _Jv_ThrowSignal () at ../../../libjava/prims.cc:113
> #6 0x40153652 in catch_segv(int) () at ../../../libjava/prims.cc:122
> #7 <signal handler called>
> #8 0x4016db3b in _Jv_IsAssignableFrom(java::lang::Class*,
> java::lang::Class*) (target=0x83fb9a0, source=0x8604fb8)
> at ../../../libjava/java/lang/natClass.cc:958
> #9 0x4016dc0a in _Jv_IsInstanceOf (obj=0x861efe0, cl=0x83fb9a0) at ../../../libjava/java/lang/natClass.cc:993
> #10 0x4015d81e in __gcj_personality_v0 (version=1, actions=1,
> exception_class=5138137972373280321, ue_header=0x8738360,
> context=0xbf782d94) at ../../../libjava/exception.cc:348
> #11 0x4002734b in _Unwind_RaiseException (exc=0x8738360) at ../../gcc/unwind-dw2.c:981
> #12 0x4015d169 in _Jv_Throw (value=0x861efe0) at ../../../libjava/exception.cc:104
> #13 0x40153624 in _Jv_ThrowSignal () at ../../../libjava/prims.cc:113
> #14 0x40153652 in catch_segv(int) () at ../../../libjava/prims.cc:122
> #15 <signal handler called> #16 0x4016db3b in _Jv_IsAssignableFrom(java::lang::Class*,
> java::lang::Class*) (target=0x83fb9a0, source=0x8604fb8)
> at ../../../libjava/java/lang/natClass.cc:958
> #17 0x4016dc0a in _Jv_IsInstanceOf (obj=0x861efe0, cl=0x83fb9a0) at
> ../../../libjava/java/lang/natClass.cc:993 #18 0x4015d81e in __gcj_personality_v0 (version=1,
> actions=1, exception_class=5138137972373280321, ue_header=0x87383a0, context=0xbf78318c)
> at ../../../libjava/exception.cc:348
> #19 0x4002734b in _Unwind_RaiseException (exc=0x87383a0) at ../../gcc/unwind-dw2.c:981
> #20 0x4015d169 in _Jv_Throw (value=0x861efe0) at ../../../libjava/exception.cc:104
This looks a bit like the bug discussed in
< http://gcc.gnu.org/ml/java/2001-05/msg00277.html >
< http://gcc.gnu.org/ml/java/2001-06/msg00003.html >
Maybe the patch in those emails helps?
Note that I don't know exactly why it fixes the problem in that case
and nobody else seems to have looked at it.
> How do you guys debug? Where do i have to set a breakpoint and in which
> thread?
Yeah, I would also like to have a (lib)gcj debugging guide.
Cheers,
Mark
-- 
Stuff to read:
 < http://www.toad.com/gnu/whatswrong.html >
 What's Wrong with Copy Protection, by John Gilmore