view m4/pipe2.m4 @ 15426:60c6b6da0198

ffs: avoid undefined behavior * lib/ffs.c (ffs): Provide fallback for non-32-bit int. * tests/test-ffs.c (naive, main): Avoid signed shifts. Reported by Bruno Haible. Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Fri, 15 Jul 2011 14:26:43 -0600
parents 97fc9a21a8fb
children 8250f2777afc
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# pipe2.m4 serial 2
dnl Copyright (C) 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,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_PIPE2],
[
  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])

  dnl Persuade glibc <unistd.h> to declare pipe2().
  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])

  AC_CHECK_FUNCS_ONCE([pipe2])
  if test $ac_cv_func_pipe2 != yes; then
    HAVE_PIPE2=0
  fi
])