1dnl ###################################################################### 2dnl NTP_VPATH_HACK 3dnl 4dnl Compiling ntpd doesn't require YACC or Bison unless ntp_parser.y is 5dnl modified, because the output ntp_parser.[ch] are committed. This 6dnl raises an issue with Automake-generated Makefiles on non-GNU make 7dnl used from a build tree outside the source tree. 8dnl 9dnl With GNU make, ylwrap updates $srcdir/ntp_parser.[ch] directly. 10dnl Under Sun or BSD make, ylwrap needs those files to be in the build 11dnl tree. 12dnl 13dnl With VPATH_HACK enabled, ntpd/Makefile.am includes code to symlink 14dnl from ntp_parser.[ch] in the build tree to the corresponding files 15dnl in $srcdir, and to check for ylwrap replacing the .h with a normal 16dnl file, and in that case copy the updated .h to $srcdir and restore 17dnl the symlink. 18dnl 19dnl if we are building outside the srcdir and either 20dnl force_ntp_vpath_hack is yes 21dnl or 22dnl we're not using GNU make 23dnl then we want VPATH_HACK to be true for .am tests 24dnl 25AC_DEFUN([NTP_VPATH_HACK], [ 26AC_MSG_CHECKING([to see if we need ylwrap VPATH hack]) 27ntp_vpath_hack="no" 28case "$srcdir::${force_ntp_vpath_hack-no}" in 29 .::*) 30 ;; # VPATH_HACK path is for VPATH builds only. 31 *::yes) 32 ntp_vpath_hack="yes" 33 ;; 34 *::*) 35 case "`${MAKE-make} -v -f /dev/null 2>/dev/null | grep 'GNU Make'`" in 36 '') 37 ntp_vpath_hack="yes" 38 esac 39esac 40AC_MSG_RESULT([$ntp_vpath_hack]) 41AM_CONDITIONAL([VPATH_HACK], [test x$ntp_vpath_hack = xyes]) 42]) 43dnl ====================================================================== 44