pipe: Set errno upon failure.

[gnulib.git] / m4 / sys_utsname_h.m4

diff --git a/m4/sys_utsname_h.m4 b/m4/sys_utsname_h.m4
index 7833536..3a9535c 100644 (file)
--- a/m4/sys_utsname_h.m4
+++ b/m4/sys_utsname_h.m4
@@ -1,5 +1,5 @@
-# sys_utsname_h.m4 serial 3
-dnl Copyright (C) 2009, 2010 Free Software Foundation, Inc.
+# sys_utsname_h.m4 serial 5
+dnl Copyright (C) 2009-2010 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.
@@ -12,6 +12,7 @@ AC_DEFUN([gl_SYS_UTSNAME_H],
   dnl once only, before all statements that occur in other macros.
   AC_REQUIRE([gl_SYS_UTSNAME_H_DEFAULTS])
 
+  dnl <sys/utsname.h> is always overridden, because of GNULIB_POSIXCHECK.
   gl_CHECK_NEXT_HEADERS([sys/utsname.h])
   AC_CHECK_HEADERS_ONCE([sys/utsname.h])
   if test $ac_cv_header_sys_utsname_h != yes; then
@@ -24,6 +25,11 @@ AC_DEFUN([gl_SYS_UTSNAME_H],
       ]])
   fi
   AC_SUBST([HAVE_SYS_UTSNAME_H])
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[#include <sys/utsname.h>
+    ]], [uname])
 ])
 
 AC_DEFUN([gl_SYS_UTSNAME_MODULE_INDICATOR],