1# ioctl.m4 serial 4
2dnl Copyright (C) 2008-2014 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7AC_DEFUN([gl_FUNC_IOCTL],
8[
9  AC_REQUIRE([gl_SYS_IOCTL_H_DEFAULTS])
10  AC_REQUIRE([gl_HEADER_SYS_SOCKET])
11  HAVE_IOCTL=1
12  if test "$ac_cv_header_winsock2_h" = yes; then
13    dnl Even if the 'socket' module is not used here, another part of the
14    dnl application may use it and pass file descriptors that refer to
15    dnl sockets to the ioctl() function. So enable the support for sockets.
16    HAVE_IOCTL=0
17  else
18    AC_CHECK_FUNCS([ioctl])
19    dnl On glibc systems, the second parameter is 'unsigned long int request',
20    dnl not 'int request'. We cannot simply cast the function pointer, but
21    dnl instead need a wrapper.
22    AC_CACHE_CHECK([for ioctl with POSIX signature],
23      [gl_cv_func_ioctl_posix_signature],
24      [AC_COMPILE_IFELSE(
25         [AC_LANG_PROGRAM(
26            [[#include <sys/ioctl.h>]],
27            [[extern
28              #ifdef __cplusplus
29              "C"
30              #endif
31              int ioctl (int, int, ...);
32            ]])
33         ],
34         [gl_cv_func_ioctl_posix_signature=yes],
35         [gl_cv_func_ioctl_posix_signature=no])
36      ])
37    if test $gl_cv_func_ioctl_posix_signature != yes; then
38      REPLACE_IOCTL=1
39    fi
40  fi
41])
42