net_if: new module

[gnulib.git] / m4 / net_if_h.m4

diff --git a/m4/net_if_h.m4 b/m4/net_if_h.m4
new file mode 100644 (file)
index 0000000..171101f
--- /dev/null
+++ b/m4/net_if_h.m4
@@ -0,0 +1,31 @@
+# net_if_h.m4 serial 1
+dnl Copyright (C) 2006-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_HEADER_NET_IF],
+[
+  AC_CACHE_CHECK([whether <net/if.h> is self-contained],
+    [gl_cv_header_net_if_h_selfcontained],
+    [
+      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <net/if.h>]], [[]])],
+        [gl_cv_header_net_if_h_selfcontained=yes],
+        [gl_cv_header_net_if_h_selfcontained=no])
+    ])
+  if test $gl_cv_header_net_if_h_selfcontained = yes; then
+    NET_IF_H=''
+  else
+    NET_IF_H='net/if.h'
+    AC_CHECK_HEADERS([net/if.h], [], [], [[#include <sys/socket.h>]])
+    gl_NEXT_HEADERS([net/if.h])
+    if test $ac_cv_header_net_if_h = yes; then
+      HAVE_NET_IF_H=1
+    else
+      HAVE_NET_IF_H=0
+    fi
+    AC_SUBST([HAVE_NET_IF_H])
+  fi
+  AC_SUBST([NET_IF_H])
+  AM_CONDITIONAL([GL_GENERATE_NET_IF_H], [test -n "$NET_IF_H"])
+])