elispcomp - Compile Emacs Lisp code from the command-line

The elispcomp command line tool allows compiling Emacs Lisp (Elisp) code directly from the terminal or from a shell script. It facilitates the generation of optimized .elc (byte-compiled) and .eln (native-compiled) files, which can significantly improve the performance of Emacs.

The command line tool executes a headless instance of Emacs and Elisp that recursively scans the specified directories, byte compiling and native compiling all the .el files that haven't been compiled yet. It supports various configuration options, allowing you to adapt the compilation process to suit your needs.

When configured appropriately, Emacs can compile to both .elc and .eln files. However, for those who wish to automate the background compilation of .el files using a script, the elispcomp command-line tool can be beneficial in ensuring that their Emacs setup remains up-to-date without manual intervention and without starting an Emacs instance.

Installation

To get started with elispcomp, you can install it using pip:

pip install --user elispcomp

This command installs elispcomp and places the executable in your ~/.local/bin/ directory, making it easily accessible from your command line.

Requirements

• Python 3
• Emacs >= 28

Usage

The elispcomp command line tool is straightforward to use.

First example: To compile all .el files located in the ~/.emacs.d/lisp directory:

elispcomp ~/.emacs.d/lisp

Second example: To compile all .el files located in the ~/.emacs.d/lisp directory, and store the native-compiled files in the ~/.emacs.d/eln-cache directory:

elispcomp --eln-cache ~/.emacs.d/eln-cache ~/.emacs.d/lisp

Command line options

usage: elispcomp [--option] [N]

Recursively byte and native compile .el files.

positional arguments:
  N                     The directories to be scanned recursively by Emacs to locate the '.el'
                        files for compilation.

options:
  -h, --help            show this help message and exit
  -c ELN_CACHE, --eln-cache ELN_CACHE
                        The eln-cache directory where Emacs stores the compiled native compiled
                        code. Defaults to the default Emacs eln-cache directory.
  -e EMACS_BIN, --emacs-bin EMACS_BIN
                        Path to the Emacs binary. Defaults: emacs
  -j JOBS, --jobs JOBS  Specify the number of parallel jobs for compilation. Default: Half the
                        number of available CPUs
  -b, --disable-byte-compile, --disable-byte-comp
                        Disable byte compile. Default: enabled
  -n, --disable-native-compile, --disable-native-comp
                        Disable native compilation. Default: enabled
  -i LOAD_PATH, --load-path LOAD_PATH
                        Recursively adds the subdirectories of the specified directory to the
                        Emacs `load-path`. This option can be used multiple times to include
                        several directories.
  -a, --ensure-native-compile-available, --ensure-native-comp-available
                        Fail when native compilation is not available.

Frequently asked questions

Can't I achieve the same result using Emacs?

Indeed, when configured appropriately, Emacs can compile to both .elc and .eln files.

The elispcomp command-line tool is an Emacs wrapper that makes it easy to compile Emacs Lisp (Elisp) code directly from the terminal or from a script. It provides options and ensures that the byte compilation and native compilation processes are truly finished before quitting.

The elispcomp command-line tool can also be used in conjunction with other tools like parallel to speed up the compilation process.

How does the author utilize elispcomp?

The author utilizes the elispcomp tool to compile multiple Emacs Lisp files across various machines and Emacs versions. With a diverse range of machines and Emacs versions in his workflow, elispcomp ensures consistent compilation results and compatibility.

Additionally, the author employs the parallel command-line tool to enhance the efficiency of the byte-compilation process. This tool allows the distribution of the compilation workload across multiple processors, significantly accelerating the process.

Is elispcomp written in Python or Elisp?

Most of what elispcomp does is written in Elisp (Emacs Lisp), including scanning directories, which is handled by the Emacs functions (byte-recompile-directory) and (native-compile-async). Python handles the command-line interface (arguments), and Emacs and the Elisp code does the rest (byte compilation, native compilation, and waiting until all the .el files are byte compiled and native compiled).

License

The elispcomp Emacs package has been written by James Cherti and is distributed under terms of the GNU General Public License version 3, or, at your choice, any later version.

Copyright (c) 2024 James Cherti

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/.

Links

• elispcomp @GitHub
• elispcomp @PyPI
• Article: Introducing elispcomp: Compiling Elisp code directly from the command line

Other Emacs packages by the same author:

• minimal-emacs.d: This repository hosts a minimal Emacs configuration designed to serve as a foundation for your vanilla Emacs setup and provide a solid base for an enhanced Emacs experience.
• vim-tab-bar.el: Make the Emacs tab-bar Look Like Vim’s Tab Bar.
• outline-indent.el: An Emacs package that provides a minor mode that enables code folding and outlining based on indentation levels for various indentation-based text files, such as YAML, Python, and any other indented text files.
• easysession.el: Easysession is lightweight Emacs session manager that can persist and restore file editing buffers, indirect buffers/clones, Dired buffers, the tab-bar, and the Emacs frames (with or without the Emacs frames size, width, and height).
• tomorrow-night-deepblue-theme.el: The Tomorrow Night Deepblue Emacs theme is a beautiful deep blue variant of the Tomorrow Night theme, which is renowned for its elegant color palette that is pleasing to the eyes. It features a deep blue background color that creates a calming atmosphere. The theme is also a great choice for those who miss the blue themes that were trendy a few years ago.
• Ultyas: A command-line tool designed to simplify the process of converting code snippets from UltiSnips to YASnippet format.
• dir-config.el: Automatically find and evaluate .dir-config.el Elisp files to configure directory-specific settings.
• flymake-bashate.el: A package that provides a Flymake backend for the bashate Bash script style checker.
• flymake-ansible-lint.el: An Emacs package that offers a Flymake backend for ansible-lint.