184 lines
9.1 KiB
EmacsLisp
184 lines
9.1 KiB
EmacsLisp
;;; early-init.el -*- lexical-binding: t; -*-
|
|
;;; Commentary:
|
|
;;
|
|
;; early-init.el was introduced in Emacs 27.1 and is loaded before init.el;
|
|
;; before Emacs initializes package.el and its UI; and before site files are
|
|
;; loaded. This is the best time to tweak Emacs (though any UI work will have to
|
|
;; be deferred), and will always be where Doom's dirtiest (and config-agnostic)
|
|
;; startup optimizations will live.
|
|
;;
|
|
;; Doom uses this file as its universal bootstrapper, for both interactive and
|
|
;; non-interactive sessions. It's also the heart of its bootloader, which lets
|
|
;; you switch between Emacs configs on demand using `--init-directory DIR'
|
|
;; (which it has backported from Emacs 29) or `--profile NAME` (for more about
|
|
;; this, read the Profiles section in docs/developers.org or
|
|
;; `https://docs.doomemacs.org/developers').
|
|
;;
|
|
;; If you're writing a Doom-based batch script, or using Doom's CLI framework,
|
|
;; load this file to initialize Doom and its CLI framework. Then you may
|
|
;; optionally load `doom-start' to initialize your interactive config on top of
|
|
;; it, if you need it.
|
|
;;
|
|
;;; Code:
|
|
|
|
;; PERF: Garbage collection is a big contributor to startup times. This fends it
|
|
;; off, then is reset later by enabling `gcmh-mode'. Not resetting it will
|
|
;; cause stuttering/freezes.
|
|
(setq gc-cons-threshold most-positive-fixnum)
|
|
|
|
(eval-and-compile
|
|
;; PERF: Don't use precious startup time checking mtime on elisp bytecode.
|
|
;; Ensuring correctness is 'doom sync's job, not the interactive session's.
|
|
;; Still, stale byte-code will cause *heavy* losses in startup efficiency.
|
|
(setq load-prefer-newer noninteractive))
|
|
|
|
;; UX: If debug mode is on, be more verbose about loaded files.
|
|
(setq force-load-messages init-file-debug)
|
|
|
|
;; PERF: Employ various startup optimizations. This benefits all sessions,
|
|
;; including noninteractive ones...
|
|
(unless (or (daemonp) ; ...but be more liberal in daemon sessions
|
|
init-file-debug ; ...and don't interfere with the debugger
|
|
(boundp 'doom-version)) ; ...or if doom is already loaded
|
|
|
|
;; PERF: `file-name-handler-alist' is consulted on each `require', `load' and
|
|
;; various path/io functions (like `expand-file-name' or `file-remote-p').
|
|
;; You get a noteable, boost to startup times by unsetting this.
|
|
(let ((old-file-name-handler-alist file-name-handler-alist))
|
|
(setq file-name-handler-alist
|
|
;; HACK: If the bundled elisp for this Emacs install isn't
|
|
;; byte-compiled (but is compressed), then leave the gzip file
|
|
;; handler there so Emacs won't forget how to read read them.
|
|
;;
|
|
;; calc-loaddefs.el is our heuristic for this because it is built-in
|
|
;; to all supported versions of Emacs, and calc.el explicitly loads
|
|
;; it uncompiled. This ensures that the only other, possible
|
|
;; fallback would be calc-loaddefs.el.gz.
|
|
(if (eval-when-compile
|
|
(locate-file-internal "calc-loaddefs.el" load-path nil))
|
|
nil
|
|
(list (rassq 'jka-compr-handler file-name-handler-alist))))
|
|
;; ...but restore `file-name-handler-alist' later, because it is needed for
|
|
;; handling encrypted or compressed files, among other things.
|
|
(defun doom-reset-file-handler-alist-h ()
|
|
(setq file-name-handler-alist
|
|
;; Merge instead of overwrite because there may have been changes to
|
|
;; `file-name-handler-alist' since startup we want to preserve.
|
|
(delete-dups (append file-name-handler-alist
|
|
old-file-name-handler-alist))))
|
|
(add-hook 'emacs-startup-hook #'doom-reset-file-handler-alist-h 101))
|
|
|
|
;; PERF: Site files tend to use `load-file', which emits "Loading X..."
|
|
;; messages in the echo area. Writing to the echo-area triggers a redisplay,
|
|
;; which can be expensive during startup. This can also cause an ugly flash
|
|
;; of white when first creating the frame. This attempts try to avoid both.
|
|
(define-advice load-file (:override (file) silence)
|
|
(load file nil :nomessage))
|
|
|
|
;; FIX: ...Then undo our `load-file' advice later, as to limit the scope of
|
|
;; any edge cases it may possibly introduce.
|
|
(define-advice startup--load-user-init-file (:before (&rest _) init-doom)
|
|
(advice-remove #'load-file #'load-file@silence)))
|
|
|
|
|
|
;;
|
|
;;; Detect `user-emacs-directory'
|
|
|
|
;; Prevent recursive profile processing, in case you're loading a Doom profile.
|
|
(unless (boundp 'doom-version)
|
|
;; Not using `command-switch-alist' to process --profile and --init-directory
|
|
;; was intentional. `command-switch-alist' is processed too late at startup to
|
|
;; change `user-emacs-directory' in time.
|
|
|
|
;; DEPRECATED: Backported from Emacs 29.
|
|
(let ((initdir (or (cadr (member "--init-directory" command-line-args))
|
|
(getenv-internal "EMACSDIR"))))
|
|
(when initdir
|
|
;; FIX: Discard the switch to prevent "invalid option" errors later.
|
|
(push (cons "--init-directory" (lambda (_) (pop argv))) command-switch-alist)
|
|
(setq user-emacs-directory (expand-file-name initdir))))
|
|
|
|
(let ((profile (or (cadr (member "--profile" command-line-args))
|
|
(getenv-internal "DOOMPROFILE"))))
|
|
(when profile
|
|
;; FIX: Discard the switch to prevent "invalid option" errors later.
|
|
(push (cons "--profile" (lambda (_) (pop argv))) command-switch-alist)
|
|
;; While processing the requested profile, Doom loosely expects
|
|
;; `user-emacs-directory' to be changed. If it doesn't, then you're using
|
|
;; profiles.el as a glorified, runtime dir-locals.el (which is fine, if
|
|
;; intended).
|
|
(catch 'found
|
|
(let ((profiles-file (expand-file-name "profiles.el" user-emacs-directory)))
|
|
(when (file-exists-p profiles-file)
|
|
(with-temp-buffer
|
|
(let ((coding-system-for-read 'utf-8-auto))
|
|
(insert-file-contents profiles-file))
|
|
(condition-case-unless-debug e
|
|
(let ((profile-data (cdr (assq (intern profile) (read (current-buffer))))))
|
|
(dolist (var profile-data (if profile-data (throw 'found t)))
|
|
(if (eq (car var) 'env)
|
|
(dolist (env (cdr var)) (setenv (car env) (cdr env)))
|
|
(set (car var) (cdr var)))))
|
|
(error (error "Failed to parse profiles.el: %s" (error-message-string e))))))
|
|
;; If the requested profile isn't in profiles.el, then see if
|
|
;; $EMACSDIR/profiles/$DOOMPROFILE exists. These are implicit
|
|
;; profiles, where `emacs --profile foo` will be equivalent to `emacs
|
|
;; --init-directory $EMACSDIR/profile/foo', if that directory exists.
|
|
(let ((profile-dir
|
|
(expand-file-name
|
|
profile (or (getenv-internal "DOOMPROFILESDIR")
|
|
(expand-file-name "profiles/" user-emacs-directory)))))
|
|
(when (file-directory-p profile-dir)
|
|
(setq user-emacs-directory profile-dir)
|
|
(throw 'found t)))
|
|
|
|
(user-error "No %S profile found" profile)))
|
|
|
|
(when init-file-debug
|
|
(message "Selected profile: %s" profile))
|
|
;; Ensure the selected profile persists through the session
|
|
(setenv "DOOMPROFILE" profile))))
|
|
|
|
|
|
;;
|
|
;;; Bootstrap
|
|
|
|
(let (init-file)
|
|
;; Load the heart of Doom Emacs
|
|
(if (load (expand-file-name "lisp/doom" user-emacs-directory) 'noerror 'nomessage)
|
|
;; ...and prepare for an interactive session.
|
|
(if noninteractive
|
|
(require 'doom-cli)
|
|
(setq init-file (expand-file-name "doom-start" doom-core-dir)))
|
|
;; ...but if that fails, then this is likely not a Doom config.
|
|
(setq early-init-file (expand-file-name "early-init" user-emacs-directory))
|
|
(load early-init-file 'noerror 'nomessage))
|
|
|
|
;; We hijack Emacs' initfile resolver to inject our own entry point. Why do
|
|
;; this? Because:
|
|
;;
|
|
;; - It spares Emacs the effort of looking for/loading useless initfiles, like
|
|
;; ~/.emacs and ~/_emacs. And skips ~/.emacs.d/init.el, which won't exist if
|
|
;; you're using Doom (fyi: doom hackers or chemacs users could then use
|
|
;; $EMACSDIR as their $DOOMDIR, if they wanted).
|
|
;; - Later, 'doom sync' will dynamically generate its bootstrap file, which
|
|
;; will be important for Doom's profile system later. Until then, we'll use
|
|
;; lisp/doom-start.el.
|
|
;; - A "fallback" initfile can be trivially specified, in case the
|
|
;; bootstrapper is missing (if the user hasn't run 'doom sync' or is a
|
|
;; first-timer). This is an opportunity to display a "safe mode" environment
|
|
;; that's less intimidating and more helpful than the broken state errors
|
|
;; would've left Emacs in, otherwise.
|
|
;; - A generated config allows for a file IO optimized startup.
|
|
(define-advice startup--load-user-init-file (:filter-args (args) init-doom)
|
|
"Initialize Doom Emacs in an interactive session."
|
|
(list (lambda ()
|
|
(or init-file
|
|
(expand-file-name "init.el" user-emacs-directory)))
|
|
(when (boundp 'doom-profiles-dir)
|
|
(lambda ()
|
|
(expand-file-name "safe-mode@static/init.el" doom-profiles-dir)))
|
|
(caddr args))))
|
|
|
|
;;; early-init.el ends here
|