I installed this:
dup2: remove test for existence of fcntl
* m4/dup2.m4 (gl_FUNC_DUP2): Use "#ifdef FD_CLOEXEC", not
"#if HAVE_FCNTL", in the configure-time test program.
This removes the need for the AC_CHECK_FUNCS_ONCE([fcntl]),
and therefore speeds up "configure" a bit. Found while
adding the dup2 module to Emacs.
diff --git a/m4/dup2.m4 b/m4/dup2.m4
index 62e31a8..8d7f62c 100644
--- a/m4/dup2.m4
+++ b/m4/dup2.m4
@@ -1,4 +1,4 @@
-#serial 12
+#serial 13
dnl Copyright (C) 2002, 2005, 2007, 2009-2011 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -17,7 +17,6 @@ AC_DEFUN([gl_FUNC_DUP2],
], [
AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.])
])
- AC_CHECK_FUNCS_ONCE([fcntl])
if test $HAVE_DUP2 = 1; then
AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
[AC_RUN_IFELSE([
@@ -25,13 +24,13 @@ AC_DEFUN([gl_FUNC_DUP2],
#include <fcntl.h>
#include <errno.h>]],
[int result = 0;
-#if HAVE_FCNTL
+#ifdef FD_CLOEXEC
if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
result |= 1;
-#endif HAVE_FCNTL
+#endif
if (dup2 (1, 1) == 0)
result |= 2;
-#if HAVE_FCNTL
+#ifdef FD_CLOEXEC
if (fcntl (1, F_GETFD) != FD_CLOEXEC)
result |= 4;
#endif
