Re: Ada Broken with h_errno change

["Joel Sherrill <joel at OARcorp dot com>" <joel dot sherrill at OARcorp dot com>]

Thomas Quinot wrote:
> * Joel Sherrill <joel@OARcorp.com>, 2005-11-16 :
>
>
> > RTEMS has networking functions but they are not available at this stage
> > during the build.
>
>
> I am not sure I understand how this can happen (I am not familiar at all
> with the RTEMS build process). If the network functions are available on
> RTEMS, isn't it the case that corresponding header files should be
> present as well? If so why aren't they available when you build the Ada
> runtime library? If not how are these functions made available to
> applications?

You build RTEMS proper after you build the toolset with which you will 
build it.  So when you gcc, you only have access to .h files which are
properly associated with libc or libm.  Those are provided by newlib.
Headers files for networking, most tasking, and other functionality
is only available later when you build the OS.

To look at it another way, RTEMS doesn't use prebuilt binaries for the 
run-time libraries when building the tools.  We start with a fresh slate 
every time we build gcc and bootstrap our way up.  That way every object 
on the target is compiled by the same gcc.

This lets us get the full benefit of a newer and better gcc every time
we update.

> > this patch is needed to make *-rtems compile again.  OK to commit?
>
>
> I'd first like to understand what exactly the situation is.

I hope the explanation above helps make it clearer.

FWIW the extern might be better stylistically outside the function.  The
function already has more than enough conditional compilation going on.

--joel