Re: [PATCH v2] Fix building xfsprogs on 32-bit platforms

[Eric Biggers <ebiggers@google.com>]

On Wed, Nov 30, 2016 at 07:20:50PM -0500, Felix Janda wrote:
> Eric Biggers wrote:
> > xfslibs now requires that its users enable transparent largefile
> > support.  This broke building xfsprogs on 32-bit Linux (with glibc)
> > because _FILE_OFFSET_BITS=64 was not getting defined.  Although the
> > autoconf macro AC_SYS_LARGEFILE was intended to define it, this didn't
> > work because AC_SYS_LARGEFILE will only define _FILE_OFFSET_BITS in a
> > config header, which doesn't work for xfsprogs because not all .c files
> > include platform_defs.h as their first include.  Also,
> > platform_defs.h.in is not generated by autoheader and didn't contain a
> > template for _FILE_OFFSET_BITS.
> > 
> > Therefore, to fix the problem remove the useless autoconf macros and
> > instead add -D_FILE_OFFSET_BITS=64 to CFLAGS in builddefs.in.  Use
> > CFLAGS rather than PCFLAGS because this definition could be needed by
> > platforms other than "linux", and it doesn't hurt to always define it.
> 
> Sorry, for this breakage. Patch looks good to me except that also the
> now unecessary definition of AC_NEED_LFS should be removed from
> m4/package_libcdev.m4.
> 
> Removing AC_SYS_LARGEFILE also has the advantage that the configure
> script does no longer have a --disable-largefile option.
> 
> Felix

Indeed, the AC_NEED_LFS definition should be removed.  I forgot it wasn't
provided by autoconf.

I do notice that without AC_SYS_LARGEFILE we won't get largefile support for the
configuration tests in m4/package_libcdev.m4 anymore.  I think it doesn't
actually matter though.

Eric