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Diffstat (limited to 'm4/config-if-present.m4')
| -rw-r--r-- | m4/config-if-present.m4 | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/m4/config-if-present.m4 b/m4/config-if-present.m4 new file mode 100644 index 0000000..ed402ff --- /dev/null +++ b/m4/config-if-present.m4 @@ -0,0 +1,23 @@ +dnl while we can get autoconf to properly handle nonexisting +dnl directories (e.g., because a sub-package only requires and +dnl distributes a subset of the directories under ssrlApps) +dnl via +dnl if [ -d somedir ] ; then AC_CONFIG_FILES([somedir/Makefile]) ; fi +dnl this doesn't work for automake -- automake doesn't understand +dnl the shell commands. +dnl +dnl The 'TILLAC_M4_IF_PRESENT' macro tests at 'autoconf/automake'-time +dnl if the argument file with '.am' appended exists and expands +dnl $2 if it does. Otherwise, $2 is suppressed. +dnl +dnl USAGE: +dnl +dnl TILLAC_M4_IR_PRESENT( +dnl [mysubdir/Makefile], +dnl [<configure commands to configure 'mysubdir' +dnl including AC_CONFIG_FILES([mysubdir/Makefile])]) +dnl +AC_DEFUN([TILLAC_M4_IF_PRESENT], +[m4_syscmd([test -d $1]) +m4_if(0,m4_sysval,[$2])]dnl +) |