+# Function to check if compiler flag works
+# Usage: SILC_ADD_CFLAGS(FLAGS, [ACTION-IF-FAILED])
+AC_DEFUN([SILC_ADD_CFLAGS],
+[ tmp_CFLAGS="$CFLAGS"
+ CFLAGS="$CFLAGS $1"
+ AC_MSG_CHECKING(whether $CC accepts $1 flag)
+ AC_TRY_LINK([], [], [AC_MSG_RESULT(yes)], [AC_MSG_RESULT(no)
+ CFLAGS="$tmp_CFLAGS"
+ $2])
+ unset tmp_CFLAGS
+])
+
+# Function to check if compiler flag works, destination specifiable
+# Usage: SILC_ADD_CC_FLAGS(VAR, FLAGS, [ACTION-IF-FAILED])
+AC_DEFUN([SILC_ADD_CC_FLAGS],
+[ tmp_CFLAGS="$1_CFLAGS"
+ $1_CFLAGS="${$1_CFLAGS} $2"
+ AC_MSG_CHECKING(whether $CC accepts $2 flag)
+ AC_TRY_LINK([], [], [AC_MSG_RESULT(yes)], [AC_MSG_RESULT(no)
+ $1_CFLAGS="$tmp_CFLAGS"
+ $3])
+ unset tmp_CFLAGS
+])
+