Re: [commit 7.8] [patch+7.8] Fix 7.8 regression: resolve_dynamic_struct: Assertion `TYPE_NFIELDS (type) > 0' (PR 17642)

["H.J. Lu" <hjl.tools@gmail.com>]

On Mon, Dec 15, 2014 at 1:09 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Mon, Dec 15, 2014 at 12:41 PM, Joel Brobecker <brobecker@adacore.com> wrote:
>>> > This is a fairly big patch...
>>> >   1. How bad is performance without it?
>>>
>>> It was very bad, like > 100x slower.
>>
>> OK, but 100x slower than 1usec is still unnoticeable. When did you start
>> noticing it, for what kind of program (size?), and what type of delay
>> were you seeing? Also, is that a regression compared to 7.7?  The idea
>> is that, if it's just a second or two, or even ten, that's still quite
>> bearable, and unless you are absolutely sure that your patch is safe,
>> perhaps we should pass...
>>
>>> >   2. Can you find a binutils maintainer that will vouch that
>>> >      this patch is 100% safe?
>>>
>>> As the x86 binutils maintainer, do I count?
>>
>> Absolutely. I just need someone who knows the code well enough to
>> be trusted with its maintainance to stand behind the code and
>> confirm that it is considered safe. In this case, I need extra safe,
>> considering the fact that this is a .2 release.
>>
>> I hope I've described my concerns well enough for you to make
>> the decision. Now that I have explained my thought process, I feel
>> you're more qualified to make an informed decision now. Your call.
>>
>> Please remember that, if you do push it to 7.8, you'll need a PR
>> associated to is so you can document the fix in the release wiki
>> page (see fixes in GDB 7.8.2):
>> https://sourceware.org/gdb/wiki/GDB_7.8_Release
>
> The bug was filed against bintuils:
>
> https://sourceware.org/bugzilla/show_bug.cgi?id=17677
>
> since the code in question is in bfd.  But the actual bug is for GDB:
>
> https://bugs.launchpad.net/ubuntu/+source/gdb/+bug/1388999
>
> where the issues was observed.  I will retest by my patch and
> backport it to 7.8 branch.
>

There is no regression in GDB 7.8 testsuite.  I pushed my change
into 7.8 branch.  Its PR is

https://sourceware.org/bugzilla/show_bug.cgi?id=17677

Thanks.

-- 
H.J.