errno (was: Weekly reports - B)

[Solar Designer <solar@openwall.com>]

Rich,

On Mon, Jun 13, 2011 at 12:54:18AM -0400, Rich Felker wrote:
> ... errno is a macro and has been for a
> long time (ever since threads) on most systems. It's required by the
> standard to be an lvalue macro.

Any idea why glibc has __set_errno() internally instead of assigning to
its errno directly, then?  The implementation for __set_errno() does a
direct assignment anyway.  What did the glibc developers need
__set_errno() for if errno is required to be an lvalue, and do they
still need __set_errno() or is it legacy?

Meanwhile, I continue to use __set_errno() in my glibc patches, at least
for consistency with upstream's code.

Thanks,

Alexander