@node ax_require_defined
@unnumberedsec ax_require_defined

@majorheading Synopsis

@smallexample
AX_REQUIRE_DEFINED(MACRO)
@end smallexample

@majorheading Description

AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
been defined and thus are available for use.  This avoids random issues
where a macro isn't expanded.  Instead the configure script emits a
non-fatal:

@smallexample
  ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
@end smallexample

It's like AC_REQUIRE except it doesn't expand the required macro.

Here's an example:

@smallexample
  AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
@end smallexample

@majorheading Source Code

Download the
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_require_defined.m4,latest
version of @file{ax_require_defined.m4}} or browse
@uref{http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_require_defined.m4,the
macro's revision history}.

@majorheading License

@w{Copyright @copyright{} 2014 Mike Frysinger @email{vapier@@gentoo.org}}

Copying and distribution of this file, with or without modification, are
permitted in any medium without royalty provided the copyright notice
and this notice are preserved. This file is offered as-is, without any
warranty.