Add the necessary autoconf magic in order to be able to compile
anything dependent from libattr, e.g. xfs_reno. 

Shamelessly stolen from xfsdump.

Thanks to Dave Chinner for advice.

Signed-off-by: Hans-Peter Jansen <hpj@xxxxxxxxx>


Index: b/configure.ac
===================================================================
--- a/configure.ac
+++ b/configure.ac
@@ -101,6 +101,10 @@ AC_PACKAGE_NEED_UUIDCOMPARE
 AC_PACKAGE_NEED_PTHREAD_H
 AC_PACKAGE_NEED_PTHREADMUTEXINIT
 
+AC_PACKAGE_NEED_ATTRIBUTES_H
+AC_PACKAGE_NEED_ATTRIBUTES_MACROS
+AC_PACKAGE_NEED_ATTRGET_LIBATTR
+
 AC_HAVE_FADVISE
 AC_HAVE_MADVISE
 AC_HAVE_MINCORE
Index: b/include/builddefs.in
===================================================================
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -34,6 +34,7 @@ LIBTERMCAP = @libtermcap@
 LIBEDITLINE = @libeditline@
 LIBREADLINE = @libreadline@
 LIBBLKID = @libblkid@
+LIBATTR = @libattr@
 LIBXFS = $(TOPDIR)/libxfs/libxfs.la
 LIBXCMD = $(TOPDIR)/libxcmd/libxcmd.la
 LIBXLOG = $(TOPDIR)/libxlog/libxlog.la
Index: b/m4/package_attrdev.m4
===================================================================
--- /dev/null
+++ b/m4/package_attrdev.m4
@@ -0,0 +1,79 @@
+AC_DEFUN([AC_PACKAGE_NEED_ATTR_XATTR_H],
+  [ AC_CHECK_HEADERS([attr/xattr.h])
+    if test "$ac_cv_header_attr_xattr_h" != "yes"; then
+        echo
+        echo 'FATAL ERROR: attr/xattr.h does not exist.'
+        echo 'Install the extended attributes (attr) development package.'
+        echo 'Alternatively, run "make install-dev" from the attr source.'
+        exit 1
+    fi
+  ])
+
+AC_DEFUN([AC_PACKAGE_NEED_ATTR_ERROR_H],
+  [ AC_CHECK_HEADERS([attr/error_context.h])
+    if test "$ac_cv_header_attr_error_context_h" != "yes"; then
+        echo
+        echo 'FATAL ERROR: attr/error_context.h does not exist.'
+        echo 'Install the extended attributes (attr) development package.'
+        echo 'Alternatively, run "make install-dev" from the attr source.'
+        exit 1
+    fi
+  ])
+
+AC_DEFUN([AC_PACKAGE_NEED_ATTRIBUTES_H],
+  [ have_attributes_h=false
+    AC_CHECK_HEADERS([attr/attributes.h sys/attributes.h], [have_attributes_h=true], )
+    if test "$have_attributes_h" = "false"; then
+        echo
+        echo 'FATAL ERROR: attributes.h does not exist.'
+        echo 'Install the extended attributes (attr) development package.'
+        echo 'Alternatively, run "make install-dev" from the attr source.'
+        exit 1
+    fi
+  ])
+
+AC_DEFUN([AC_PACKAGE_WANT_ATTRLIST_LIBATTR],
+  [ AC_CHECK_LIB(attr, attr_list, [have_attr_list=true], [have_attr_list=false])
+    AC_SUBST(have_attr_list)
+  ])
+
+AC_DEFUN([AC_PACKAGE_NEED_GETXATTR_LIBATTR],
+  [ AC_CHECK_LIB(attr, getxattr,, [
+        echo
+        echo 'FATAL ERROR: could not find a valid Extended Attributes library.'
+        echo 'Install the extended attributes (attr) development package.'
+        echo 'Alternatively, run "make install-lib" from the attr source.'
+        exit 1
+    ])
+    libattr="-lattr"
+    test -f ${libexecdir}${libdirsuffix}/libattr.la && \
+	libattr="${libexecdir}${libdirsuffix}/libattr.la"
+    AC_SUBST(libattr)
+  ])
+
+AC_DEFUN([AC_PACKAGE_NEED_ATTRGET_LIBATTR],
+  [ AC_CHECK_LIB(attr, attr_get,, [
+        echo
+        echo 'FATAL ERROR: could not find a valid Extended Attributes library.'
+        echo 'Install the extended attributes (attr) development package.'
+        echo 'Alternatively, run "make install-lib" from the attr source.'
+        exit 1
+    ])
+    libattr="-lattr"
+    test -f ${libexecdir}${libdirsuffix}/libattr.la && \
+	libattr="${libexecdir}${libdirsuffix}/libattr.la"
+    AC_SUBST(libattr)
+  ])
+
+AC_DEFUN([AC_PACKAGE_NEED_ATTRIBUTES_MACROS],
+  [ AC_MSG_CHECKING([macros in attr/attributes.h])
+    AC_TRY_LINK([
+#include <sys/types.h>
+#include <attr/attributes.h>],
+    [ int x = ATTR_SECURE; ], [ echo ok ], [
+        echo
+	echo 'FATAL ERROR: could not find a current attributes header.'
+        echo 'Upgrade the extended attributes (attr) development package.'
+        echo 'Alternatively, run "make install-dev" from the attr source.'
+	exit 1 ])
+  ])