gdb and core files

[Jon Turney]

On 30/06/2020 04:24, Mark Geisert wrote:
> Ken Brown via Cygwin wrote:
>> On 6/28/2020 9:31 AM, Jon Turney wrote:
>>> On 28/06/2020 01:50, Ken Brown via Cygwin wrote:
>>>> Following the instructions at 
>>>> https://cygwin.com/cygwin-ug-net/using-cygwinenv.html, I tried to 
>>>> create a core file that I could examine with gdb, but I apparently 
>>>> ran into a gdb bug. I tried both gdb 9.2-1 and 8.3.1-1.  Here are 
>>>> the results with 9.2-1.
>>>>
>>> [...]
>>>
>>> Unfortunately, I think dumper doesn't produce anything useful on 
>>> x86_64. See [1] et seq.
>>
>> Thanks.  Sorry I didn't notice that people had asked the same question 
>> before.
>>
>> We should probably fix the documentation:
>>
>>    https://cygwin.com/cygwin-ug-net/using-cygwinenv.html
>>    https://cygwin.com/cygwin-ug-net/dumper.html

Yeah, with hindsight, that would have been a good idea.

> I hesitate to comment when I can't immediately work on this, but, 
> ...making dumper work on 64-bit Cygwin is on my TODO list but not right 
> at the top.  It would be helpful to keep the program around in its 
> current 32-bit state as a template for 64-bit.

I had a poke at this problem this week.

[1] https://cygwin.com/pipermail/cygwin-patches/2020q3/010313.html
[2] https://sourceware.org/pipermail/gdb-patches/2020-July/170023.html

> P.S. For the long term, I think it was Jon who suggested dumper generate 
> Windows minidumps rather than the current Frankensteinish dumps.  I 
> intend to investigate that when I get to this project.

Not quite.  There's already a tool ('minidumper') to generate minidumps. 
  But gdb can't read those (yet).