Re: [Emacs-diffs] emacs-25 33ec2ff: Add one more mod-test test

[Eli Zaretskii <eliz@gnu.org>]

> Cc: emacs-devel@gnu.org
> From: Ken Brown <kbrown@cornell.edu>
> Date: Sun, 29 Nov 2015 10:21:39 -0500
> 
> >> Does the missing "from" indicate a bug in the Cygwin build?
> >
> > It indicates that your dladdr implementation doesn't work (probably
> > returns zero).
> >
> > Please ask on the Cygwin list, and if dladdr is indeed missing, the
> > test should be updated to accommodate for this return value on Cygwin.
> 
> Thanks.  In fact, dladdr isn't implemented on Cygwin, so dynlib_addr 
> always returns false.  I'll update the test.

Thanks.

> Should the update be Cygwin-specific?  According to
> http://linux.die.net/man/3/dladdr, dladdr is a glibc extension to
> POSIX, so there could conceivably be other systems with the same
> issue.

Could be, but I don't know which systems might have this problem.  If
you or someone else have access to *BSD or Solaris, please try that
there.  I wouldn't recommend blindly do that everywhere except
GNU/Linux and Windows, because then we could miss some systems where
the functionality is available, but something needs to be done to have
it.  So I think it's best to fail (pun intended) on the safe side.