[committed][gdb] Add tsan-suppressions.txt

[Tom de Vries <tdevries@suse.de>]

On 7/12/22 12:31, Tom de Vries wrote:
> On 7/12/22 10:39, Tom de Vries wrote:
>> On 7/11/22 12:08, Tom de Vries wrote:
>>> Hi,
>>>
>>> Add a new file tsan-suppressions.txt, to suppress the "unlock 
>>> unlocked mutex"
>>> problem in ncurses, filed in PR29328.
>>>
>>> For now, one needs to specify it manually using something like:
>>> ...
>>> $ export TSAN_OPTIONS=suppressions=$(pwd 
>>> -P)/src/gdb/tsan-suppressions.txt
>>> ...
>>>
>>> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29328
>>>
>>> Any comments?
>>>
>>
>> I just found that we already set ASAN_OPTIONS in lib/gdb.exp, so I've 
>> added this TSAN_OPTIONS setting alongside.
> 
> I furthermore realized that suppression files are not cumulative, so if 
> we have suppressions=a.txt:suppressions=b.txt then only b.txt is used.
> 
> This would mean we ignore any user-specified suppression files, which 
> may contains more suppressions for whatever reason.
> 
> So I've updated the patch to only add the suppressions if the user 
> didn't already do that.

Well, that makes the whole thing harmless enough, so committed.

Thanks,
- Tom