1  # ===========================================================================
 2  #    http://www.gnu.org/software/autoconf-archive/ax_require_defined.html
 3  # ===========================================================================
 4  #
 5  # SYNOPSIS
 6  #
 7  #   AX_REQUIRE_DEFINED(MACRO)
 8  #
 9  # DESCRIPTION
10  #
11  #   AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
12  #   been defined and thus are available for use.  This avoids random issues
13  #   where a macro isn't expanded.  Instead the configure script emits a
14  #   non-fatal:
15  #
16  #     ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
17  #
18  #   It's like AC_REQUIRE except it doesn't expand the required macro.
19  #
20  #   Here's an example:
21  #
22  #     AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
23  #
24  # LICENSE
25  #
26  #   Copyright (c) 2014 Mike Frysinger <vapier@gentoo.org>
27  #
28  #   Copying and distribution of this file, with or without modification, are
29  #   permitted in any medium without royalty provided the copyright notice
30  #   and this notice are preserved. This file is offered as-is, without any
31  #   warranty.
32  
33  #serial 1
34  
35  AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
36    m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])
37  ])dnl AX_REQUIRE_DEFINED