@node ax_elisp
@unnumberedsec ax_elisp

@majorheading Synopsis

@smallexample
AX_ELISP_CONFIG_FILE(FILENAME)
AX_ELISP_CHECK(SYMBOL,DESCRIPTION,BODY,SUCCESS-EXPR)
AX_ELISP_CHECK_FEATURE(SYMBOL)
AX_ELISP_CHECK_FBOUNDP(SYMBOL,[FEATURE [...]])
AX_ELISP_CHECK_BOUNDP(SYMBOL,[FEATURE [...]])
@end smallexample

@majorheading Description

This is a simple library to check the Emacs reality by way of Emacs Lisp
forms evaluated under $EMACS --batch -Q. This means you MUST have the
shell variable EMACS set to a valid Emacs executable prior to the first
call to any of the AX_ELISP_CHECK et al macros. Those work by saving
their results to the file defined by calling AX_ELISP_CONFIG_FILE so you
MUST call that prior, too. For example:

@smallexample
  dnl Arrange to save config answers in $top_builddir/lisp/config.el.
  AX_ELISP_CONFIG_FILE([lisp/config.el])
@end smallexample

@smallexample
  dnl Set shell variable EMACS and AC_SUBST it, too.
  dnl (NB: This is a separate Autoconf Archive macro.)
  AX_PROG_EMACS
@end smallexample

In the following detailed descriptions, SYMBOL stands for an Emacs Lisp
symbol, which may contain hyphens, e.g., 'define-error' or 'org-src'.
Likewise, FEATURE is an Emacs Lisp symbol (naming a feature). BODY and
SUCCESS-EXPR are Emacs Lisp forms, zero or more for BODY and exactly one
for SUCCESS-EXPR. In these forms you must take care to avoid apostrophe
(U+27). Instead of 'foo, write (quote foo).

* AX_ELISP_CONFIG_FILE(FILENAME)

This arranges for future AX_ELISP_CHECK (et al) calls to save their
results in FILENAME. May be called multiple times. FILENAME should be
relative to the top build dir.

* AX_ELISP_CHECK(SYMBOL,DESCRIPTION,BODY,SUCCESS-EXPR)

This is the general macro that the other AX_ELISP_CHECK* macros use. It
constructs a short Emacs Lisp file comprising BODY and evaluates it via
$EMACS --batch -Q. The exit value of this script depends on the result
of evaluating SUCCESS-EXPR: non-nil is success and nil is failure. On
success, append SYMBOL on a line of its own to the config file. This
macro uses AC_CACHE_CHECK and passes DESCRIPTION to it.

* AX_ELISP_CHECK_FEATURE(FEATURE)

This checks if (require (quote FEATURE)) is successful. If so, add
featurep-FEATURE to the config file (NB the "featurep-" prefix).

* AX_ELISP_CHECK_FBOUNDP(SYMBOL,[FEATURE [...]])

This checks if (fboundp (quote SYMBOL)) is successful. If so, append
SYMBOL to the config file. Optional 2nd arg is a space-separated list of
features to require prior to the fboundp check.

* AX_ELISP_CHECK_BOUNDP(SYMBOL,[FEATURE [...]])

This checks if (boundp (quote SYMBOL)) is successful. If so, append
SYMBOL to the config file. Optional 2nd arg is a space-separated list of
features to require prior to the boundp check.

@majorheading Source Code

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

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