@node ax_prog_emacs
@unnumberedsec ax_prog_emacs

@majorheading Synopsis

@smallexample
AX_PROG_EMACS
@end smallexample

@majorheading Description

This macro allows the end user to specify a particular Emacs executable
via a configure script command-line arg. For example:

@smallexample
  ./configure EMACS=$HOME/build/GNU/emacs/src/emacs
@end smallexample

It also arranges to mention env var EMACS in the './configure --help'
output. See info node "(autoconf) Generic Programs" for details.

More precisely...

If env var EMACS is set, try to use its value directly, but avoid
getting fooled by value 't' (set by older Emacsen for subprocesses). If
no joy from the environment, search for "emacs" via AC_CHECK_PROG. If
still no joy, display "Emacs not found; required!" and make configure
exit failurefully. Otherwise, set shell var EMACS and AC_SUBST it, too.

@majorheading Source Code

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

@majorheading License

@w{Copyright @copyright{} 2016-2017 Thien-Thi Nguyen}

This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.

You should have received a copy of the GNU General Public License along
with this program. If not, see <https://www.gnu.org/licenses/>.

As a special exception, the respective Autoconf Macro's copyright owner
gives unlimited permission to copy, distribute and modify the configure
scripts that are the output of Autoconf when processing the Macro. You
need not follow the terms of the GNU General Public License when using
or distributing such scripts, even though portions of the text of the
Macro appear in them. The GNU General Public License (GPL) does govern
all other use of the material that constitutes the Autoconf Macro.

This special exception to the GPL applies to versions of the Autoconf
Macro released by the Autoconf Archive. When you make and distribute a
modified version of the Autoconf Macro, you may extend this special
exception to the GPL to apply to your modified version as well.