On Thu, Feb 04, 2021 at 10:46:58AM +0100, Jan Beulich wrote: > On 04.02.2021 10:38, Roger Pau Monne wrote: > > --- a/tools/configure.ac > > +++ b/tools/configure.ac > > @@ -74,6 +74,7 @@ m4_include([../m4/ax_compare_version.m4]) > > m4_include([../m4/paths.m4]) > > m4_include([../m4/systemd.m4]) > > m4_include([../m4/golang.m4]) > > +m4_include([../m4/header.m4]) > > > > AX_XEN_EXPAND_CONFIG() > > > > @@ -517,4 +518,6 @@ AC_ARG_ENABLE([pvshim], > > ]) > > AC_SUBST(pvshim) > > > > +AX_FIND_HEADER([INCLUDE_ENDIAN_H], [endian.h sys/endian.h]) > > Instead of a new macro, can't you use AC_CHECK_HEADERS()?
AC_CHECK_HEADERS doesn't do what we want here: it will instead produce a HAVE_header-file define for each header on the list that's present, and the action-if-found doesn't get passed the path of the found header according to the documentation. Here I want the variable to be set to the include path of the first header on the list that's present on the system. > I'm also not certain about the order of checks - what if both > exist? With my macro the first one will be picked. Thanks, Roger.
