[Libcdio-devel] LARGEFILE changes

[R. Bernstein]

The ever-watchful Steven M. Schultz reports:
 > Hi -
 > 
 >      Weirdness in the largefile changes.  I'd have thought that the
 >      AC_SYS_LARGEFILE would have been enough but apparently not...
 > 
 >      Anyhow, on OSX when running ./autogen.sh I get
 > 
 > Running autoheader...
 > autoheader: warning: missing template: HAVE_LARGEFILE_SUPPORT
 > autoheader: Use AC_DEFINE([HAVE_LARGEFILE_SUPPORT], [], [Description])
 > autoheader: warning: missing template: _FILE_OFFSET_BITS
 > autoheader: warning: missing template: _LARGE_FILES
 > Running automake --include-deps --add-missing --gnu  ...
 > 
 >      Missing AH_ line in configure.ac perhaps?
 > 
 >      Then running 'make':
 > 
 > [larry:src/libcdio-cvs] sms% gmake
 > cd . && /bin/sh /usr/local/src/libcdio-cvs/missing --run autoheader
 > autoheader: warning: missing template: HAVE_LARGEFILE_SUPPORT
 > autoheader: Use AC_DEFINE([HAVE_LARGEFILE_SUPPORT], [], [Description])
 > autoheader: warning: missing template: _FILE_OFFSET_BITS
 > autoheader: warning: missing template: _LARGE_FILES
 > 
 >      If I manually re-run ./configure again after ./autogen.sh then
 >      'make' works and compilation proceeds.
 > 
 >      I'm curious what triggered the need for the extra/different checks since
 >      other programs get by with just AC_SYS_LARGEFILE
...

Probably this is because those other programs use the AC_SYS_LARGEFILE
that comes with autoconf. I've just made a change to use that as well.

When I first tried that I noticed LARGEFILE defines were not added on
compilations on my GNU/Linux box which has glibc 2.3.90. Then I read
this from wxGTK-2.5.4/aclocal.m4:

dnl AC_SYS_LARGEFILE (partly based on the code from autoconf 2.5x)
...
dnl NB: original autoconf test was checking if compiler supported 6 bit off_t
dnl     arithmetic properly but this failed miserably with gcc under Linux
dnl     whereas the system still supports 64 bit files, so now simply check
dnl     that off_t is big enough

Believing that to be the case, I took the m4 code from wxGTK. And
probably my adapation of gave the error. I really don't know what the
current situation is with respect to autoconf 2.59 and large-file
support and don't want to know this all that well. So I've gone back
to the simple naive approach of assuming that autoconf has been fixed
since that comment.

If folks out there want to advise on this I'd be grateful.