Re: [Swarm-Support] Re:Cannot access memory 0x2000000

[Bill Northcott]

Hi Xiaojun

If you are properly running the code under gdb (see the GDB manual) 
then when it breaks you will get the error message followed by a gdb 
prompt.   Typing bt at that prompt will give you a dump of the call 
frame stack.  It does not make sense to get nothing.  You need a 
version of gdb that understands Objective-C.  With other versions you 
will get a back trace but it is harder to understand.

Your gdb session should look something like this:
[PBG4-BN:apps/objc/heatbugs] billn% gdb yourprogram
GNU gdb 5.3-20030128 (Apple version gdb-330.1) (Fri Jul 16 21:42:28 GMT 
2004)
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and 
you are
welcome to change it and/or distribute copies of it under certain 
conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for 
details.
This GDB was configured as "powerpc-apple-darwin".
Reading symbols for shared libraries ........... done
(gdb) run
Starting program: /Somepath/yourprograms
Reading symbols for shared libraries 
+++......................................................... done
error: cannot access memory 0x2000000

Program received signal SIGABRT, Aborted.
0x900429ac in kill ()
(gdb) bt
#0  0x900429ac in kill ()
#1  0x9009eb1c in abort ()
#2  0x01837004 in objc_verror (object=0x115d340, code=0, fmt=0xbffff570 
"error: TkExtra (instance)\n\n", ap=0xbffff5f4 "\001\206\212T") at 
../../../libobjc/misc.c:66
#3  0x0182de14 in -[Object error:] (self=0x115d340, _cmd=0x187f9c4, 
aString=0xa089d0c "") at ../../../libobjc/Object.m:345
#4  0x01765c90 in -[TkInterp preInitWithArgc:argv:] (self=0x115d340, 
_cmd=0x187f194, argc=1, argv=0x113bc38) at 
../../../../src/tclobjc/TkInterp.m:177
#5  0x01752338 in -[TkExtra preInitWithArgc:argv:] (self=0x115d340, 
_cmd=0x187f6e4, argc=1, argv=0x113bc38) at 
../../../../src/tkobjc/TkExtra.m:99
#6  0x017617e8 in -[TclInterp initWithArgc:argv:] (self=0x115d340, 
_cmd=0x187f9cc, argc=1, argv=0x113bc38) at 
../../../../src/tclobjc/TclInterp.m:301
#7  0x01765e4c in -[TkInterp initWithArgc:argv:] (self=0x115d340, 
_cmd=0x187f568, argc=1, argv=0x113bc38) at 
../../../../src/tclobjc/TkInterp.m:197
#8  0x01759afc in tkobjc_initTkInterp (arguments=0x113b648) at 
../../../../src/tkobjc/internal.m:154
#9  0x01758d84 in initTkObjc (arguments=0x113b648) at 
../../../../src/tkobjc/tkobjc.m:50
#10 0x016b5d4c in initSimtoolsGUI () at 
../../../../src/simtoolsgui/simtoolsgui.m:31
#11 0x01697c5c in -[SwarmEnvironment createEnd] (self=0x113b1d8, 
_cmd=0x187b0d0) at ../../../src/SwarmEnvironment.m:151
#12 0x01698bb8 in _initSwarm_ (argc=1, argv=0xbffffbdc, appName=0x947c 
"heatbugs", version=0x9488 "2.1.1", bugAddress=0x9490 
"address@hidden", argumentsClass=0x0, options=0x0, optionFunc=0, 
forceBatchMode=0 '\000', inhibitExecutableSearchFlag=0 '\000') at 
../../../src/SwarmEnvironment.m:339
#13 0x0000456c in main (argc=1, argv=0xbffffbdc) at main.m:22
(gdb)

What you need to look at is that call frame stack.

Bill

On 13/11/2004, at 2:22 PM, ºúС¾ü wrote:

> hi,Bill
>
> Thanks for your answer.
> I run the experiment model under gdb and after the programe crash, I 
> did a
> backtrace through bt and the only information i got was:
> cannot access memory 0x2000000,nothing else.
> I could not find the pointer which got the wrong value through (gdb) 
> bt.
> I am not sure if I need to add some parameters for example -d(?) to 
> allow gdb to
> debug the process.
> I'd have a try.
>
>  Best regards!
>
>  HU Xiaojun
>  Tsinghua University
>  Beijing, China
>
>
> _______________________________________________
> Support mailing list
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