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

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

[Eric Biggers]

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.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 configure.ac         | 3 ---
 include/builddefs.in | 2 +-
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index b88ab7f..ee918d1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -107,9 +107,6 @@ AC_PACKAGE_UTILITIES(xfsprogs)
 AC_MULTILIB($enable_lib64)
 AC_RT($enable_librt)
 
-AC_SYS_LARGEFILE
-AC_NEED_LFS
-
 AC_PACKAGE_NEED_UUID_H
 AC_PACKAGE_NEED_UUIDCOMPARE
 
diff --git a/include/builddefs.in b/include/builddefs.in
index aeb2905..5219071 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -25,7 +25,7 @@ OPTIMIZER = @opt_build@
 MALLOCLIB = @malloc_lib@
 LOADERFLAGS = @LDFLAGS@
 LTLDFLAGS = @LDFLAGS@
-CFLAGS = @CFLAGS@
+CFLAGS = @CFLAGS@ -D_FILE_OFFSET_BITS=64
 
 LIBRT = @librt@
 LIBUUID = @libuuid@
-- 
2.8.0.rc3.226.g39d4020

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

[Felix Janda]

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

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

[Eric Biggers]

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