LD linker stubs?

[Jeff Bailey]

I found the code in libc for creating "link_warning" constructs.  Is
there a similar construct that emulates #error in the same way?  I'm
going to hack together an initial pthreads library that will allow us
to begin porting the Hurd, but I want to make sure that any other
functions that are defined in the Header file will refuse to link if
the appropriate function is linked in.

The idea is that I want to slowly implement the functions, and make
sure that the user compiling the software is *very* aware when an
expected function is going to fail. (And hopefully force them to use
--without-threads or something)

It's late, so if this doesn't make sense, I'll resend in the morning. =)

Tks,
Jeff Bailey