Re: [boost] Running b2 on develop needs asynch-exceptions=on

Subject: Re: [boost] Running b2 on develop needs asynch-exceptions=on
From: Vladimir Prus (vladimir_at_[hidden])
Date: 2015-03-16 14:41:35

On 03/16/2015 09:23 PM, Paul A. Bristow wrote:
>
>
>> -----Original Message-----
>> From: Boost [mailto:boost-bounces_at_[hidden]] On Behalf Of Vladimir Prus
>> Sent: 16 March 2015 16:51
>> To: boost_at_[hidden]
>> Subject: Re: [boost] Running b2 on develop needs asynch-exceptions=on
>>
>> On 03/16/2015 03:19 PM, John Maddock wrote:
>>>
>>>>>
>>>>> http://lists.boost.org/Archives/boost/2015/03/220552.php
>>>>>
>>>>> looks as though a  fix is still needed?
>>>>
>>>> Since I did not get a response, I went ahead removing all
>>>> <asynch-exceptions>on from Boost.Test Jamfile, and pushed to devel branch. Could you give it a
> try?
>>>>
>>>> Should further changes be needed, they can be done at later time -
>>>> subject to keeping top-level build with no options working.
>>>>
>>>
>>> I'm not at all sure this is the right fix: I believe Boost.Test really does need
> asynch-exception support
>> turned on to work it's magic.
>>
>> In that thread, Gennadiy say it does not need that from Boost.System, that it only needs client to
> set that.
>> It's not quite clear whether Boost.Test itself should be built with that or not.
>>
>> Anyway, my primary point, if you allow a bit of ranting, is that it's clearly Boost.Test that
> tries to use
>> custom settings that cause issues, but the people who appear to care most are Jürgen and Paul and
> you
>> and I, neither of whom are Boost.Test maintainers. That's not really productive. So with this
> change, it's up
>> to Boost.Test maintainers to do whatever is right, which might be updating documentation, or using
> just
>> explicit /EHa cflags, or something else.
>
> I'm exceptionally confused, but if I have zillions of VC project files which assume test is built
> with /EHa, then I assume I need the Boost.Test library built with /EHa.
>
> (unless I change them all and/or lose some of Boost.Test functionality - none of which are
> attractive).
>
> I also suspect that I am not alone in this desire.
>
> What I have done (explicit <asynch-exceptions>on)  seems to work.  So do we need to just update the
> docs?  But it had better be in VERY BIG LETTERS  because it would be a breaking change for very many
> users?  I'm the only one shouting because I'd had to rebuild after a GIT glitch, but there be many
> others to follow?

It probably builds, but then Peter has said that building all of Boost with asynch-exceptions is a bad idea.

I still haven't got an authorative answer whether it should be Boost.Test that builds with /EHa (so that it
can catch SEH exception), or whether client code with tests be built with /EHa (so that it converts
SEH exceptions into C++ exceptions) or something else.

-- 
Vladimir Prus
CodeSourcery / Mentor Embedded
http://vladimirprus.com