Re: Some questions

[Mark Wielaard <mark at klomp dot org>]

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
-- 
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