[patch] Fix oddity in personality routine

[Andrew Haley]

Jack Howarth wrote:
> On Mon, Nov 16, 2009 at 03:16:07PM +0000, Andrew Haley wrote:
>> Jack Howarth wrote:
>>>    I should also add that my results from testing the
>>> various i386 and x86_64 fink gcc44 and gcc45 packages
>>> under darwin9 and darwin10 are confusing. I find for
>>> gcj compiling java (but not class) files...
>>>
>>>            i386-darwin9   x86_64-darwin9  i386-darwin10  x86_darwin10
>>> gcc 4.4.2    works           aborts         aborts          aborts
>>> gcc 4.5      aborts          aborts         aborts          aborts
>>>
>>> I have a backport of the darwin10 patches from gcc 4.4
>>> that I can add to the current gcc 4.3 branch and try that
>>> but my gut instinct is that at best we will only find some
>>> revision where the latent problem is triggered but not
>>> indicating the exact origin of the problem.
>>>                Jack
>>> ps It might still be a good first step to make the Makefiles
>>> coherent (which they don't seem to be at the moment) with
>>> regard to the ecjx linkage flags.
>> The first step surely would be to have a look and see why ecj1 is
>> aborting.

>    I'll double check with my patch from http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41991#c10
> but originally ecj1 was failing as shown in the backtrace of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41991#c1.

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.

Andrew.