diff options
Diffstat (limited to 'm4/jhflags.m4')
| -rw-r--r-- | m4/jhflags.m4 | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/m4/jhflags.m4 b/m4/jhflags.m4 new file mode 100644 index 0000000..222e4b0 --- /dev/null +++ b/m4/jhflags.m4 @@ -0,0 +1,21 @@ +dnl +dnl JH_ADD_CFLAG(FLAG) +dnl checks whether the C compiler supports the given flag, and if so, adds +dnl it to $CFLAGS. If the flag is already present in the list, then the +dnl check is not performed. +AC_DEFUN([JH_ADD_CFLAG], +[ +case " $CFLAGS " in +*@<:@\ \ @:>@$1@<:@\ \ @:>@*) + ;; +*) + save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS $1" + AC_MSG_CHECKING([whether [$]CC understands $1]) + AC_TRY_COMPILE([], [], [jh_has_option=yes], [jh_has_option=no]) + AC_MSG_RESULT($jh_has_option) + if test $jh_has_option = no; then + CFLAGS="$save_CFLAGS" + fi + ;; +esac]) |