Option -pthread in test suite with cross compilers

[Joel Sherrill]

On 05/18/2012 10:50 AM, Ian Lance Taylor wrote:
> Joel Sherrill<joel.sherrill@oarcorp.com>  writes:
>
>> On 05/18/2012 09:05 AM, Ian Lance Taylor wrote:
>>> Joel Sherrill<joel.sherrill@oarcorp.com>   writes:
>>>
>>>> On 05/18/2012 08:27 AM, Ian Lance Taylor wrote:
>>>>> Ralf Corsepius<ralf.corsepius@rtems.org>    writes:
>>>>>
>>>>>> I am not sure, but AFAICT, -pthread is Linux-specific.
>>>>> It's not properly documented, but -pthread works on a number of hosts,
>>>>> including Solaris, Darwin, FreeBSD, NetBSD, OpenBSD, AIX.
>>>> Ian.. Is it better to make it a noop for RTEMS or fix the test
>>>> infrastructure that is turning it on where it doesn't exist?
>>> Sorry to be vague, but I think it depends on whether the tests are
>>> meaningful on RTEMS.  If dg-require-effective-target pthread_h lets a
>>> test run, then I suppose I think the -pthread option ought to work.
>> Ok to be vague. :)
>>
>> Is there an implicit assumption that having pthread.h
>> means a target has libpthread.a and support for the
>> -pthread option?
>>
>> That's a bit of a reach. We have good pthread.h support
>> but include that in librtemscpu.a which is implicitly linked
>> against all the time. And obviously no -pthread option.
>>
>> if the tests are checking some pthread capability, then
>> we should be running them.
>>
>> I don't mind having -pthread be a noop but the leap
>> from a having a header file to having a specific gcc
>> option is a stretch IMO. Unless EVERY gcc target with
>> pthread support is required by gcc to have that option.
>> Is that the undocumented(?) intent?
> Some systems require the -pthread option to get fully correct behaviour
> for threaded programs (the -pthread option implies -lpthread,
> incidentally).  I think it would be reasonable for RTEMS to accept the
> -pthread option.  I also think it would be reasonable to fix the
> testsuite to only use -pthread on systems that require it.
Ian for President in 2012! Way to walk the fence :)

I agree with you on this one. Would it be a good general
rule that on a system with pthreads, -pthread should be
accepted by gcc? You didn't mention Cygwin in your list
but otherwise, it is pretty complete.
> Ian


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