xfsprogs: don't warn about packed members

gcc 9.2.1 throws lots of new warnings during the build like this:

xfs_format.h:790:3: warning: taking address of packed member of ‘struct xfs_agfl’ may result in an unaligned pointer value [-Waddress-of-packed-member]
  790 |   &(XFS_BUF_TO_AGFL(bp)->agfl_bno[0]) : \
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xfs_alloc.c:3149:13: note: in expansion of macro ‘XFS_BUF_TO_AGFL_BNO’
 3149 |  agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
      |             ^~~~~~~~~~~~~~~~~~~

We know this packed structure aligned correctly, so turn off this
warning to shut gcc up.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
[sandeen: kernel has done this globally as well in 6f303d60534]
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/include/builddefs.in b/include/builddefs.in
index 2987f0b8972240d2f689b676fcc15f9317c15c1d..891bf93d7aa38bcaa3ca71e505ccb849dfcd7cf1 100644 (file)
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -13,7 +13,7 @@ OPTIMIZER = @opt_build@
 MALLOCLIB = @malloc_lib@
 LOADERFLAGS = @LDFLAGS@
 LTLDFLAGS = @LDFLAGS@
-CFLAGS = @CFLAGS@ -D_FILE_OFFSET_BITS=64
+CFLAGS = @CFLAGS@ -D_FILE_OFFSET_BITS=64 -Wno-address-of-packed-member
 BUILD_CFLAGS = @BUILD_CFLAGS@ -D_FILE_OFFSET_BITS=64
 
 LIBRT = @librt@