autoconf: Tolerate missing file when grepping.

[sliver-openvswitch.git] / acinclude.m4

diff --git a/acinclude.m4 b/acinclude.m4
index 80794da..0af7fd0 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -108,21 +108,26 @@ dnl
 dnl Greps FILE for REGEX.  If it matches, runs IF-MATCH, otherwise IF-NO-MATCH.
 AC_DEFUN([OVS_GREP_IFELSE], [
   AC_MSG_CHECKING([whether $2 matches in $1])
-  grep '$2' $1 >/dev/null 2>&1
-  status=$?
-  case $status in
-    0) 
-      AC_MSG_RESULT([yes])
-      $3
-      ;;
-    1) 
-      AC_MSG_RESULT([no])
-      $4
-      ;;
-    *) 
-      AC_MSG_ERROR([grep exited with status $status]) 
-      ;;
-  esac
+  if test -f $1; then
+    grep '$2' $1 >/dev/null 2>&1
+    status=$?
+    case $status in
+      0) 
+        AC_MSG_RESULT([yes])
+        $3
+        ;;
+      1) 
+        AC_MSG_RESULT([no])
+        $4
+        ;;
+      *) 
+        AC_MSG_ERROR([grep exited with status $status])
+        ;;
+    esac
+  else
+    AC_MSG_RESULT([file not found])
+    $4
+  fi
 ])
 
 dnl OVS_DEFINE(NAME)
@@ -188,6 +193,8 @@ AC_DEFUN([OVS_CHECK_LINUX26_COMPAT], [
 
   OVS_GREP_IFELSE([$KSRC26/include/linux/types.h], [bool],
                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
+  OVS_GREP_IFELSE([$KSRC26/include/linux/types.h], [__wsum],
+                  [OVS_DEFINE([HAVE_CSUM_TYPES])])
 
   OVS_GREP_IFELSE([$KSRC26/include/net/checksum.h], [csum_unfold],
                   [OVS_DEFINE([HAVE_CSUM_UNFOLD])])