Re: Document reasonable portability targets

[Bruno Haible]

Hello Bastien,

> I am trying to help bruce with error.c in order to determine the program name 
> automatically on the so called "reasonable portability targets", but I could 
> not find a list of this targets...
> 
> Could we document it ?

It's already implicitly documented, in the chapter about each function:
<http://www.gnu.org/software/gnulib/manual/gnulib.html#Function-Substitutes>
For example, the function posix_trace_attr_init, which no system implements,
is marked as:
  "This function is missing on some platforms:
   glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1,
   HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, Interix 3.5, BeOS."

Eliminate the version numbers, and you have the systems about which we worry:

  glibc, MacOS X, FreeBSD, NetBSD, OpenBSD, AIX, HP-UX IRIX, OSF/1, Solaris,
  Cygwin, mingw, Interix, BeOS.

Over time we've effectively dropped Interix and BeOS and started to support
MirBSD instead:

  glibc, MacOS X, FreeBSD, NetBSD, OpenBSD, MirBSD, AIX, HP-UX, IRIX, OSF/1,
  Solaris, Cygwin, mingw.

Bruno