errno.h: ESTRPIPE

[Jeff Johnston]

Ralf Corsepius wrote:
> Christopher Faylor wrote:
>> On Mon, Mar 16, 2009 at 08:29:26AM +0100, Ralf Corsepius wrote:
>>  
>>> newlib should stay with well established standards and not be polluted
>>> with underdocumented, proprietary extensions.
>>>     
>>
>> Do you have any other irrational prejudices you'd like to share with us?
> No, simply point me to an official (POSIX, IEEE, ANSII or similar) 
> standard documenting ESTRPIPE.
>
> Ralf
>
Hi Ralf,

According to Posix Section 2.4 states:

"Implementations may support additional errors not listed in this 
clause, but shall not generate a different error number from one 
required  by this part of ISO/IEC 9945 for an error condition described 
in this part of ISO/IEC 9945...."

Similarly under SUSV:

"Additional implementation-dependent error numbers may be defined in 
<errno.h>"

Finally, glibc contains a number of errno extensions and it includes 
ESTRPIPE.  Newlib often adopts glibc extensions as requested in the 
interest of making it easier to port code to newlib.

That said, if RTEMS absolutely doesn't want any of these extensions 
there are two alternatives.  1. Simply write a sys/errno.h file with 
only standard-provided errno values.  If only standard-provided errnos 
plus RTEMS extensions are to be supported, this makes the most sense as 
you don't really require a common file and it will likely rarely require 
maintenance.  2. Add flag checks to sys/errno.h that segregate the 
extensions and only remove them if the flag is defined (by default all 
are provided).  For example,  __NO_ERRNO_EXTENSIONS__.

Seem reasonable?

-- Jeff J.