Automake provides a separate variable for preprocessor flags (*_CPPFLAGS). They are already uses in a few places, so make it consistent and use it everywhere. Note that cflags obtained from pkg-config often are cppflags, which is why LIBXML2_CFLAGS moves with into AM_CPPFLAGS, for example. Change-Id: I15feed1d18b2ca497371271c4b5876d5ec6289dd BUG: 862082 Original-author: Jan Engelhardt <jengelh@inai.de> Signed-off-by: Jan Engelhardt <jengelh@inai.de> Signed-off-by: Jeff Darcy <jdarcy@redhat.com> Reviewed-on: http://review.gluster.org/4029 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com>