[PATCH v3] Fix building xfsprogs on 32-bit platforms

[Eric Biggers <ebiggers@google.com>]

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 +-
 m4/package_libcdev.m4 | 16 ----------------
 3 files changed, 1 insertion(+), 20 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@
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index e3c59d8..7d5a42d 100644
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -258,22 +258,6 @@ AC_DEFUN([AC_HAVE_MREMAP],
   ])
 
 #
-# Check if transparent LFS is enabled
-#
-AC_DEFUN([AC_NEED_LFS],
-  [ AC_MSG_CHECKING([whether large file support works])
-    AC_TRY_COMPILE([
-#include <unistd.h>
-    ], [
-         int i[sizeof(off_t)-8];
-    ], AC_MSG_RESULT(yes),
-       [AC_MSG_RESULT(no)
-       echo
-       echo 'FATAL ERROR: C library does not support transparent LFS.'
-       exit 1])
-  ])
-
-#
 # Check if we need to override the system struct fsxattr with
 # the internal definition.  This /only/ happens if the system
 # actually defines struct fsxattr /and/ the system definition
-- 
2.8.0.rc3.226.g39d4020