From: Pierre Labastie <>

Autoheader uses the AC_DEFINE macros (and a few others) to populate
the file. The autotools documentation does not tell
what happens if AC_DEFINE is used twice for the same identifier.

This patch prevents using AC_DEFINE twice for
HAVE_OWN_FIEMAP_EXTENT_DEFINE, preserving the logic (using the
fact that an undefined identifier in a preprocessor directive is
taken as zero).

Note that I doubt this check is needed in configure:
HAVE_OWN_FIEMAP_EXTENT_DEFINE is used only once in cmds/filesystem-du.c
but HAVE_OWN_FIEMAP_EXTENT_SHARED_DEFINE is set to 1 by configure only if
FIEMAP_EXTENT_SHARED is not defined in the kernel headers.

If you agree, I'll send a patch to completely remove this check.

Pierre Labastie (1):
  btrfs-progs: build system - do not use AC_DEFINE twice | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)


Reply via email to