1 files changed, 79 insertions, 0 deletions
diff --git a/m4/sys_ioctl_h.m4 b/m4/sys_ioctl_h.m4
new file mode 100644
index 0000000..be65364
--- /dev/null
+++ b/m4/sys_ioctl_h.m4
@@ -0,0 +1,79 @@
+# sys_ioctl_h.m4 serial 15
+dnl Copyright (C) 2008-2022 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.
+
+dnl Written by Bruno Haible.
+
+AC_DEFUN_ONCE([gl_SYS_IOCTL_H],
+[
+  dnl Ensure to expand the default settings once only, before all statements
+  dnl that occur in other macros.
+  AC_REQUIRE([gl_SYS_IOCTL_H_DEFAULTS])
+
+  AC_CHECK_HEADERS_ONCE([sys/ioctl.h])
+  if test $ac_cv_header_sys_ioctl_h = yes; then
+    HAVE_SYS_IOCTL_H=1
+    dnl Test whether <sys/ioctl.h> declares ioctl(), or whether some other
+    dnl header file, such as <unistd.h> or <stropts.h>, is needed for that.
+    AC_CACHE_CHECK([whether <sys/ioctl.h> declares ioctl],
+      [gl_cv_decl_ioctl_in_sys_ioctl_h],
+      [dnl We cannot use AC_CHECK_DECL because it produces its own messages.
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[#include <sys/ioctl.h>]],
+            [[(void) ioctl;]])],
+         [gl_cv_decl_ioctl_in_sys_ioctl_h=yes],
+         [gl_cv_decl_ioctl_in_sys_ioctl_h=no])
+      ])
+  else
+    HAVE_SYS_IOCTL_H=0
+  fi
+  AC_SUBST([HAVE_SYS_IOCTL_H])
+  dnl <sys/ioctl.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([sys/ioctl.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/ioctl.h>
+/* Some platforms declare ioctl in the wrong header.  */
+#if !(defined __GLIBC__ && !defined __UCLIBC__)
+# include <unistd.h>
+#endif
+    ]], [ioctl])
+])
+
+# gl_SYS_IOCTL_MODULE_INDICATOR([modulename])
+# sets the shell variable that indicates the presence of the given module
+# to a C preprocessor expression that will evaluate to 1.
+# This macro invocation must not occur in macros that are AC_REQUIREd.
+AC_DEFUN([gl_SYS_IOCTL_MODULE_INDICATOR],
+[
+  dnl Ensure to expand the default settings once only.
+  gl_SYS_IOCTL_H_REQUIRE_DEFAULTS
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+# Initializes the default values for AC_SUBSTed shell variables.
+# This macro must not be AC_REQUIREd.  It must only be invoked, and only
+# outside of macros or in macros that are not AC_REQUIREd.
+AC_DEFUN([gl_SYS_IOCTL_H_REQUIRE_DEFAULTS],
+[
+  m4_defun(GL_MODULE_INDICATOR_PREFIX[_SYS_IOCTL_H_MODULE_INDICATOR_DEFAULTS], [
+    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_IOCTL])
+  ])
+  m4_require(GL_MODULE_INDICATOR_PREFIX[_SYS_IOCTL_H_MODULE_INDICATOR_DEFAULTS])
+  AC_REQUIRE([gl_SYS_IOCTL_H_DEFAULTS])
+])
+
+AC_DEFUN([gl_SYS_IOCTL_H_DEFAULTS],
+[
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  SYS_IOCTL_H_HAVE_WINSOCK2_H=0; AC_SUBST([SYS_IOCTL_H_HAVE_WINSOCK2_H])
+  SYS_IOCTL_H_HAVE_WINSOCK2_H_AND_USE_SOCKETS=0;
+                        AC_SUBST([SYS_IOCTL_H_HAVE_WINSOCK2_H_AND_USE_SOCKETS])
+  REPLACE_IOCTL=0;      AC_SUBST([REPLACE_IOCTL])
+])