POSIX Compilance- #2966, GSoC Project 2019

[Joel Sherrill]

On Mon, Mar 18, 2019 at 9:06 AM Vaibhav Gupta <vaibhavgupta40 at gmail.com>
wrote:

> Okay, i read the header file, the functions defined in
>
> https://docs.rtems.org/branches/master/posix-compliance/posix-compliance.html#id396
> are still missing.
> .
> Can they be taken up for SoC project?
>

Yep. As I tried to make clear on the other response, the implementation of
fenv.h
is target architecture dependent.

+ The Cygwin fenv.h is possibly x86 and/or x86_64. It can be moved as
appropriate
so the implementation is available to all users of that architecture.

+ Other architectures like ARM, PowerPC, SPARC, etc will need to be located
and ported to newlib or written. Just a quick search of the net turned up
this
directory from FreeBSD's github which has a number of architectures.

This by itself is not going to be a full GSoC project but it is a good
first ticket to
tackle in a set of POSIX Compliance tasks.

--joel


> On Mon, Mar 18, 2019 at 7:19 PM Vaibhav Gupta <vaibhavgupta40 at gmail.com>
> wrote:
>
>> Ticket no #2971 https://devel.rtems.org/ticket/2971
>>
>> The header file is present in newlib:
>>
>> $ find ./ -name \fenv.h
>> ./newlib-cygwin/winsup/cygwin/include/fenv.h
>> ./newlib-cygwin/newlib/libc/machine/spu/sys/fenv.h
>> ./newlib-cygwin/newlib/libc/machine/spu/include/fenv.h
>> ./newlib-cygwin/newlib/libc/machine/riscv/sys/fenv.h
>> ./newlib-cygwin/newlib/libc/machine/riscv/include/fenv.h
>>
>> ./newlib-cygwin/winsup/cygwin/include/fenv.h   contains full
>> imlementation
>> as defined on http://pubs.opengroup.org/onlinepubs/9699919799/
>>
>> On Mon, Mar 18, 2019 at 7:04 PM Vaibhav Gupta <vaibhavgupta40 at gmail.com>
>> wrote:
>>
>>> Ticket no #3650 https://devel.rtems.org/ticket/3650
>>>
>>> The header file is present in newlib:
>>> $ find ./ -name \ipc.h
>>> ./newlib-cygwin/winsup/cygwin/include/sys/ipc.h
>>> ./newlib-cygwin/winsup/cygwin/include/cygwin/ipc.h
>>> ./newlib-cygwin/newlib/libc/sys/phoenix/sys/ipc.h
>>> .
>>> and
>>> ./newlib-cygwin/winsup/cygwin/include/cygwin/ipc.h contains whole
>>> implementation.
>>> I guess, now we can enable the sys/ipc.h POSIX API Compliance Tests.
>>>
>>> On Sun, Mar 17, 2019 at 11:03 PM Vaibhav Gupta <vaibhavgupta40 at gmail.com>
>>> wrote:
>>>
>>>>
>>>>
>>>> On Sun, Mar 17, 2019 at 9:43 PM Joel Sherrill <joel at rtems.org> wrote:
>>>>
>>>>>
>>>>>
>>>>> On Sat, Mar 16, 2019, 2:49 PM Vaibhav Gupta <vaibhavgupta40 at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Hello,
>>>>>> As mentioned by Dr Joel that high priority is to be given to
>>>>>> implementations missing in FACE GPP 3.0.
>>>>>> So, I have got FACE Technical Standard 3.0 pdf downloaded. And its
>>>>>> pretty easy to compare tickets now.
>>>>>>
>>>>>
>>>>> The FACE Technical Standard is a long and sleep inducing read. :)
>>>>>
>>>>> We have a POSIX Compliance document which tracks RTEMS vs various
>>>>> POSIX profiles. Many standards have POSIX profiles. SCA is for software
>>>>> radios. FACE TS was designed for cockpit software. Use the compliance
>>>>> document for ease:
>>>>>
>>>>> https://docs.rtems.org/branches/master/posix-compliance/index.html
>>>>>
>>>> Thanks, I guess this document contains the list of methods that are
>>>> already supported. I was comparing tickets with FACE to find which all are
>>>> still in need to be addressed.
>>>>
>>>>
>>>>>
>>>>> I track compliance against every standard I can find.
>>>>>
>>>> This is best for RTEMS
>>>>
>>>>>
>>>>> FYI I have supported the FACE Consortium for a number of years in
>>>>> various roles.
>>>>>
>>>>>
>>>>>
>>>>> .
>>>>>> And while exploring big picture I got many questions:
>>>>>>
>>>>>> 1 - It is mentioned in the ticket #2966, *"RTEMS POSIX Compliance is
>>>>>> achieved via a combination of methods and .h files in RTEMS and the newlib
>>>>>> C Library."* .
>>>>>> So, if a method or a header is present in Newlib C, it is not
>>>>>> required to be present in RTEMS library? But that would mean Newlib is
>>>>>> directly ported to RTEMS.
>>>>>>
>>>>>
>>>>> POSIX includes the entire C Library in its definition. Newlib is our C
>>>>> Library so if the method makes sense to be there, we add it to Newlib.
>>>>>
>>>>> In general, threading and synchronisation go in RTEMS. But ask for
>>>>> specific methods. It isn't always obvious.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> .
>>>>>>
>>>>>> *> I had an off-list talk with Vijay, he proved to be very helpful. I
>>>>>> asked him same question (question 1), I would like to conclude what we
>>>>>> discussed. *
>>>>>>
>>>>>> *> He told that "RTEMS uses its own version of Newlib C as it cannot
>>>>>> directly mirror original Newlib as, if methods change the way it works,
>>>>>> they can break RTEMS".*
>>>>>>
>>>>>>
>>>>>> *> But then my doubt was, if that's the case, why keep modified
>>>>>> headers of original Newlib under separate Newlib C folder in RTEMS? Why not
>>>>>> directly include them in RTEMS library? (As I found newlib-1d35a003f.tar.gz
>>>>>> in {RTEMS-ROOT}/rsb/rtems/sources/    )*
>>>>>> *.*
>>>>>> *> To which he replied,  "RTEMS version of newlib is being used as a
>>>>>> libraby of RTEMS only and the posix functions are being linked to this
>>>>>> newlib"*
>>>>>> .
>>>>>> 2- So, My second doubt is that our target is to contribute to Newlib
>>>>>> C or RTEMS Library? Or we will add methods to Newlib C and link them to
>>>>>> RTEMS?
>>>>>>
>>>>>> Thanks
>>>>>> Vaibhav Gupta
>>>>>>
>>>>>
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