Re: ["Eli Zaretskii" <address@hidden>] Re: configure: a.out.h vs nlist.h

[Akim Demaille]

| It seems like AC_FUNC_GETLOADAVG does not define NLIST_STRUCT any more,
| even though getloadavg.c needs it and it is documentated.
| 
| Andreas.
| 
| From: "Eli Zaretskii" <address@hidden>
| Subject: Re: configure: a.out.h vs nlist.h
| To: Andreas Schwab <address@hidden>
| Cc: address@hidden, address@hidden
| X-Sent: 6 days, 1 hour, 6 minutes, 56 seconds ago
| Reply-To: Eli Zaretskii <address@hidden>
| 
| > From: Sam Steingold <address@hidden>
| > Date: 24 Oct 2001 16:24:28 -0400
| > 
| > > > From: Sam Steingold <address@hidden>
| > > > Date: 24 Oct 2001 12:55:05 -0400
| > > > 
| > > > On the current CVS emacs, I get this:
| > > > getloadavg.c:356:24: a.out.h: No such file or directory
| > > > after 'make distclean; ./configure; make bootstrap'
| > > > on Solaris 2.5.1, gcc 3.0, autoconf 2.52.
| > > 
| > > That's weird: according to "cvs log", getloadavg.c didn't change since
| > > June 2000.  Could you please look closer at this and see what changed
| > > since the last pretest you built (did you build any pretests on that
| > > machine?).
| > > 
| > > Is it possible that this is the first time some of the tools are used,
| > > or a new version of some tool?
| > 
| > I think I was not clear enough.
| > the problem is obviously with the recent changes in the configuration
| > process, i.e., the check for a.out.h vs nlist.h (see the subject line)
| > in configure.  I suspect that when aclocal.m4 was dropped, the check
| > went away too, so the default include (a.out.h) is used now always.
| 
| The problem is not with aclocal.m4, it's with the new Autoconf: its
| AC_FUNC_GETLOADAVG macro doesn't seem to define NLIST_STRUCT, and
| getloadavg.c needs that, at least on your system.
| 
| Andreas, could you please look into this?
| 
| ----------

I don't think this was meant :(

But looking at the code from 2.13:

  AC_CHECK_HEADER(nlist.h,
  [AC_DEFINE(NLIST_STRUCT)
  AC_CACHE_CHECK([for n_un in struct nlist], ac_cv_struct_nlist_n_un,
  [AC_TRY_COMPILE([#include <nlist.h>],

it seems useless: Just check HAVE_NLIST_H (the code in 2.50 does
define the symbol).  As a matter of fact, looking at the version in
the fileutils, I see:

# ifndef NLIST_STRUCT
#  if HAVE_NLIST_H
#   define NLIST_STRUCT
#  endif
# endif

Can't getloadavg.c be simplified instead?  What is its master?