- (dtucker) [configure.ac openbsd-compat/sys-tree.h] Test if compiler allows

__attribute__ on return values and work around if necessary.  ok djm@

ChangeLog

@@ -1,6 +1,8 @@
 20130208
  - (djm) [contrib/redhat/sshd.init] treat RETVAL as an integer;
    patch from Iain Morgan in bz#2059
+ - (dtucker) [configure.ac openbsd-compat/sys-tree.h] Test if compiler allows
+   __attribute__ on return values and work around if necessary.  ok djm@
 
 20130207
  - (djm) [configure.ac] Don't probe seccomp capability of running kernel

configure.ac

@@ -1,4 +1,4 @@
-# $Id: configure.ac,v 1.501 2013/02/06 23:11:05 djm Exp $
+# $Id: configure.ac,v 1.502 2013/02/08 00:50:09 dtucker Exp $
 #
 # Copyright (c) 1999-2004 Damien Miller
 #
@@ -15,7 +15,7 @@
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 AC_INIT([OpenSSH], [Portable], [openssh-unix-dev@mindrot.org])
-AC_REVISION($Revision: 1.501 $)
+AC_REVISION($Revision: 1.502 $)
 AC_CONFIG_SRCDIR([ssh.c])
 AC_LANG([C])
 
@@ -238,6 +238,18 @@ if test "$GCC" = "yes" || test "$GCC" = "egcs"; then
 	fi
 fi
 
+AC_MSG_CHECKING([if compiler allows __attribute__ on return types])
+AC_COMPILE_IFELSE(
+    [AC_LANG_PROGRAM([[
+#include <stdlib.h>
+__attribute__((__unused__)) static void foo(void){return;}]],
+    [[ exit(0); ]])],
+    [ AC_MSG_RESULT([yes]) ],
+    [ AC_MSG_RESULT([no])
+      AC_DEFINE(NO_ATTRIBUTE_ON_RETURN_TYPE, 1,
+	 [compiler does not accept __attribute__ on return types]) ]
+)
+
 if test "x$no_attrib_nonnull" != "x1" ; then
 	AC_DEFINE([HAVE_ATTRIBUTE__NONNULL__], [1], [Have attribute nonnull])
 fi

openbsd-compat/sys-tree.h

@@ -26,6 +26,11 @@
 
 /* OPENBSD ORIGINAL: sys/sys/tree.h */
 
+#include "config.h"
+#ifdef NO_ATTRIBUTE_ON_RETURN_TYPE
+# define __attribute__(x)
+#endif
+
 #ifndef	_SYS_TREE_H_
 #define	_SYS_TREE_H_