OpenBSD hangs / crashes with Suduku

[Riccardo Mottola]

Hi,

I am able to reproduce the problems Sebastian has on my own OpenBSD/x86 
box. I get this problem only on OpenBSD. I use gcc and its standard 
runtime. The same combination appears to work fine on NetBSD or Linux.

The problem happens with "New" inside Sudoku (latest version from CVS of 
GAP).

The happening is:

1) Sudoku is run  normally (not in GDB). Sudokup.apps remains eternally 
at 99% of CPU usage and hangs
2) If run inside GDB, I get the same broken crash of Sebastian:
#0  0x0d8ea287 in NSCountFrames () at NSDebug.m:1009
#1  0x0d8edf19 in GSPrivateStackAddresses () at NSDebug.m:1112
#2  0x0d902f5f in -[GSStackTrace init] (self=0x7d17a2e8, _cmd=0x2d8e89e8)
    at NSException.m:605
#3  0x0d951942 in +[NSObject new] (self=0x2d8cfac0, _cmd=0x2d8cfb40)
    at NSObject.m:1281
#4  0x0d90387c in -[NSException raise] (self=0x7d17a168, _cmd=0x2d8cfba8)
    at NSException.m:960
#5  0x0d902e04 in +[NSException raise:format:arguments:] (self=0x2d8cf9c0,
    _cmd=0x2d8cfb90, name=0x3c00615c, format=0x3c006150,
    argList=0xcfbf0a80 "ðR÷\213h¾O'\027\003") at NSException.m:849
#6  0x0d903cf3 in +[NSException raise:format:] (self=0x2d8cf9c0,
    _cmd=0x3c0060f8, name=0x3c00615c, format=0x3c006150) at 
NSException.m:835
#7  0x1c0070ad in -[Sudoku doFind:] (self=0x7e509008, _cmd=0x3c0060d8,
    seen=0x87e36fc8) at Sudoku.m:457
#8  0x1c006fbe in -[Sudoku doFind:] (self=0x7e509008, _cmd=0x3c0060d8,
    seen=0x87e36fc8) at Sudoku.m:524
#9  0x1c006fbe in -[Sudoku doFind:] (self=0x7e509008, _cmd=0x3c0060d8,
    seen=0x87e36fc8) at Sudoku.m:524
#10 0x1c006fbe in -[Sudoku doFind:] (self=0x7e509008, _cmd=0x3c0060d8,
    seen=0x87e36fc8) at Sudoku.m:524
#11 0x1c006fbe in -[Sudoku doFind:] (self=0x7e509008, _cmd=0x3c0060d8,
    seen=0x87e36fc8) at Sudoku.m:524


I can also put a breakpoint in NSException raise and get the similar output:

#0  -[NSException raise] (self=0x7c139488, _cmd=0x2835eba8)
    at NSException.m:956
#1  0x08391e04 in +[NSException raise:format:arguments:] (self=0x2835e9c0,
    _cmd=0x2835eb90, name=0x3c006174, format=0x3c006168,
    argList=0xcfbf01f0 "0÷\234\201h®\210&\027\003") at NSException.m:849
#2  0x08392cf3 in +[NSException raise:format:] (self=0x2835e9c0,
    _cmd=0x3c0060f8, name=0x3c006174, format=0x3c006168) at 
NSException.m:835
#3  0x1c006f80 in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:452
#4  0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524
#5  0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524
#6  0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524
#7  0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524
#8  0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524
#9  0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524
#10 0x1c006fbe in -[Sudoku doFind:] (self=0x84f0a008, _cmd=0x3c0060d8,
    seen=0x87651648) at Sudoku.m:524

the exception is raised from line 452;
      [NSException raise:EX_COMPLETE format:EX_COMPLETE_FMT];

line 524:
          [self doFind:seen];

(which means indeed recursion)


Seen as this it looks like a code problem, but if it happens only on  
OpenBSD I think of some kind of corruption. "placed" gets initialized 
before...

Thanks,
  Riccardo


and seq is an object instance variable, which makes me think of 
corruption in the object.