Re: [patch] Fix oddity in personality routine

[Andrew Haley <aph at redhat dot com>]

Jack Howarth wrote:
> On Mon, Nov 16, 2009 at 04:58:10PM +0000, Andrew Haley wrote:
>> Jack Howarth wrote:
>>> On Mon, Nov 16, 2009@03:16:07PM +0000, Andrew Haley wrote:

>> Here:
>>
>>   /* If code == _URC_END_OF_STACK, then we reached top of stack without
>>      finding a handler for the exception.  Since each thread is run in
>>      a try/catch, this oughtn't happen.  If code is something else, we
>>      encountered some sort of heinous lossage from which we could not
>>      recover.  As is the way of such things, almost certainly we will have
>>      crashed before now, rather than actually being able to diagnose the
>>      problem.  */
>>   abort();
>>
>> In other words, the stack unwinder has failed.  I can't see any alternative
>> to stepping through the unwinder to find out why.

>    Can you walk me through the process of stepping through the unwinder?
> Is there a good breakpoint to set so that the process of stepping through
> the unwinder isn't so painful. I think we should start with darwin9 since
> it will be using the FSF libgcc's unwinder.

There's another unwinder?  Gosh.

Set a bp on '_Jv_Throw' and step through.  You'll need to compile libgcc
with -O0 or you'll go insane.  The unwinder is quite complex, and it takes
a fair while to understand it.

Andrew.