added a configure check routine to automatically detect a difference(*1) in

TAILQ_FOREACH_REVERSE macros.  (Suggested by Brute STEVANT)

*1)
Some OS (*BSD) adopts the following definition,
	#define	TAILQ_FOREACH_REVERSE(var, head, headname, field)
 but others (MacOS-X, old OpenBSD) adopts the following definition
	#define	TAILQ_FOREACH_REVERSE(var, head, field, headname)

3 files changed, 145 insertions, 0 deletions

diff --git a/common.h b/common.h
index 194829d..c10b65d 100644
--- a/common.h
+++ b/common.h
@@ -84,6 +84,9 @@
 	    (var);							\
 	    (var) = TAILQ_NEXT((var), field))
 #endif
+#ifdef HAVE_TAILQ_FOREACH_REVERSE_OLD
+#undef TAILQ_FOREACH_REVERSE
+#endif
 #ifndef TAILQ_FOREACH_REVERSE
 #define	TAILQ_FOREACH_REVERSE(var, head, headname, field)		\
 	for ((var) = TAILQ_LAST((head), headname);			\
diff --git a/configure b/configure
index 05ad1cc..a0d1dfe 100755
--- a/configure
+++ b/configure
@@ -5293,6 +5293,108 @@ _ACEOF
 esac
 
 
+echo "$as_me:$LINENO: checking checking the existence TAILQ_FOREACH_REVERSE" >&5
+echo $ECHO_N "checking checking the existence TAILQ_FOREACH_REVERSE... $ECHO_C" >&6
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <sys/queue.h>
+ #ifdef TAILQ_FOREACH_REVERSE
+  yes
+#endif
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "yes" >/dev/null 2>&1; then
+  result=yes
+fi
+rm -f conftest*
+
+echo "$as_me:$LINENO: result: $result" >&5
+echo "${ECHO_T}$result" >&6
+case $result in
+yes)	tailq_foreach=yes
+ 	;;
+*)	tailq_foreach=no
+	;;
+esac
+
+if test $tailq_foreach = yes) {
+	echo "$as_me:$LINENO: checking argument order of TAILQ_FOREACH_REVERSE" >&5
+echo $ECHO_N "checking argument order of TAILQ_FOREACH_REVERSE... $ECHO_C" >&6
+	cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+	#include <stdio.h>
+	#include <sys/queue.h>
+
+	TAILQ_HEAD(tailhead, entry) head = TAILQ_HEAD_INITIALIZER(head);
+	struct entry {
+		TAILQ_ENTRY(entry) entries;
+	} *p;
+
+	int i;
+	struct tailhead *headp;
+
+	TAILQ_FOREACH_REVERSE(p, headp, tailhead, entries) {
+	}
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"
+			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  echo "$as_me:$LINENO: result: new" >&5
+echo "${ECHO_T}new" >&6
+	 cat >>confdefs.h <<\_ACEOF
+#define HAVE_TAILQ_FOREACH_REVERSE 1
+_ACEOF
+
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+echo "$as_me:$LINENO: result: old" >&5
+echo "${ECHO_T}old" >&6
+	 cat >>confdefs.h <<\_ACEOF
+#define HAVE_TAILQ_FOREACH_REVERSE_OLD 1
+_ACEOF
+
+fi
+rm -f conftest.err conftest.$ac_objext conftest.$ac_ext;
+fi
+
 
 for ac_header in stdarg.h
 do
diff --git a/configure.in b/configure.in
index 624061f..19e8d38 100644
--- a/configure.in
+++ b/configure.in
@@ -147,6 +147,46 @@ esac
 dnl DHCP option type values not officially defined
 dnl (no such option now)
 
+dnl Checks the existence of TAILQ_FOREACH_REVERSE
+AC_MSG_CHECKING(checking the existence TAILQ_FOREACH_REVERSE)
+AC_EGREP_CPP(yes,
+[#include <sys/queue.h>
+ #ifdef TAILQ_FOREACH_REVERSE
+  yes
+#endif], [result=yes], [result=no])
+AC_MSG_RESULT($result)
+case $result in
+yes)	tailq_foreach=yes
+ 	;;
+*)	tailq_foreach=no
+	;;
+esac
+
+dnl Checks the argument order of TAILQ_FOREACH_REVERSE if it exists
+if test $tailq_foreach = yes ; then
+	AC_MSG_CHECKING(argument order of TAILQ_FOREACH_REVERSE)
+	AC_TRY_COMPILE([],
+	[
+	#include <stdio.h>
+	#include <sys/queue.h>
+
+	TAILQ_HEAD(tailhead, entry) head = TAILQ_HEAD_INITIALIZER(head);
+	struct entry {
+		TAILQ_ENTRY(entry) entries;
+	} *p;
+
+	int i;
+	struct tailhead *headp;
+
+	TAILQ_FOREACH_REVERSE(p, headp, tailhead, entries) {
+	}
+	],
+	[AC_MSG_RESULT(new)
+	 AC_DEFINE(HAVE_TAILQ_FOREACH_REVERSE)],
+	[AC_MSG_RESULT(old)
+	 AC_DEFINE(HAVE_TAILQ_FOREACH_REVERSE_OLD)]);
+fi
+
 AC_CHECK_HEADERS(stdarg.h)
 
 AC_OUTPUT(Makefile)