Re: Emacs hangs enabling debug-on-error

[Robert Mecklenburg]

KFS> I'm not sure why that causes a hang, but once we understand what
KFS> triggers it, it will be easier to solve that as well.
KFS> 
KFS> Can you try to look at the following data objects:
KFS> 
RM> #26 0x0817fa39 in call_debugger (arg=-1455901112) at eval.c:265
KFS> 
KFS> p arg
KFS> pr

(gdb) frame 26
#26 0x0817fa39 in call_debugger (arg=-1446621520) at eval.c:265
265       val = apply1 (Vdebugger, arg);
(gdb) p arg
$2 = -1446621520
(gdb) pr
(error (void-function nil))


RM> #28 0x081814e7 in Fsignal (error_symbol=675401312, data=-1455901008) at 
eval.c:1507
KFS> 
KFS> p error_symbol
KFS> pr

(gdb) frame 28
#28 0x081814e7 in Fsignal (error_symbol=675401312, data=-1446621496) at 
eval.c:1507
1507          clause = find_handler_clause (handlerlist->handler, conditions,
(gdb) p error_symbol
$3 = 675401312
(gdb) pr
void-function


KFS> p data
KFS> pr

Oops, I missed this one.  I'll send it along with the next hang.


RM> #29 0x0817290c in Findirect_function (object=675340304) at data.c:1923
KFS> 
KFS> p object
KFS> pr

(gdb) frame 29
#29 0x0817290c in Findirect_function (object=675340304) at data.c:1923
1923        return Fsignal (Qvoid_function, Fcons (object, Qnil));
(gdb) p object
$4 = 675340304
(gdb) pr
nil


RM> #30 0x08182107 in Feval (form=-1458405528) at eval.c:2006
KFS> 
KFS> p form
KFS> pr

(gdb) frame 30
#30 0x08182107 in Feval (form=-1457499584) at eval.c:2006
2006      fun = Findirect_function (original_fun);
(gdb) p form
$5 = -1457499584
(gdb) pr
(nil)


RMS> Is it really hanging or is it looping?
RMS> If it is looping, please look at the instructions
RMS> in etc/DEBUG about such cases.  If it is really hanging,
RMS> please try to see why the system call doesn't wake up.

I sent the process a TSTP and then typed step, the process appeared
to hang.  Repeat and then typed finish, the process appeared to
hang - at least neither step nor finish returned a gdb prompt.

Hope this helps,
-- 
Robert