gnu: emacs: Adapt the autoloads auxiliary code to use EMACSLOADPATH.

The Elisp directories to scan for autoloads are now taken from EMACSLOADPATH
instead of from the user profile, environment profile or system profile.
Manually adding the Elisp directories to the `load-path' is no longer
necessary, as this is covered by Emacs when they are in EMACSLOADPATH.  The
caching logic is also removed, as this code is not typically run often and the
gain is marginal (loading autoloads files is cheap).

* gnu/packages/aux-files/emacs/guix-emacs.el (guix-emacs-directory)
(guix-emacs-subdirs, guix-emacs-directories): Remove procedures.
(guix-emacs-find-autoloads): Filter the directory entries by passing the
regexp to `directory-files' directly, which is ten times faster.  Remove
deduplication.
(guix-emacs-autoloads-regexp): Remove the group, which used to filter out the
file extension; it no longer works this way due to passing the regexp to the
`directory-files' procedure directly, which doesn't care about groups.
(guix-emacs-autoload-packages): Update doc.  Search package directories from
EMACSLOADPATH.  Do not populate the load-path.  Remove cache.

1 files changed, 24 insertions, 74 deletions

diff --git a/gnu/packages/aux-files/emacs/guix-emacs.el b/gnu/packages/aux-files/emacs/guix-emacs.el
index 9a49e8861c..46ee557f20 100644
--- a/gnu/packages/aux-files/emacs/guix-emacs.el
+++ b/gnu/packages/aux-files/emacs/guix-emacs.el
@@ -2,6 +2,7 @@
 
 ;; Copyright © 2014, 2015, 2016, 2017 Alex Kost <alezost@gmail.com>
 ;; Copyright © 2017 Kyle Meyer <kyle@kyleam.com>
+;; Copyright © 2019 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 
 ;; This file is part of GNU Guix.
 
@@ -24,91 +25,40 @@
 ;; installed with Guix.
 
 ;;; Code:
-
-(require 'cl-lib)
-
-(defvar guix-user-profile (expand-file-name "~/.guix-profile"))
-
-(defvar guix-emacs-autoloads nil
-  "List of the last loaded Emacs autoloads.")
+(require 'seq)
 
 (defvar guix-emacs-autoloads-regexp
-  (rx (group (* any) "-autoloads")
-      ".el" (zero-or-one "c") string-end)
+  (rx (* any) "-autoloads.el" (zero-or-one "c") string-end)
   "Regexp to match Emacs 'autoloads' file.")
 
-(defun guix-emacs-directory (&optional profile)
-  "Return directory with Emacs packages installed in PROFILE.
-If PROFILE is nil, use `guix-user-profile'."
-  (expand-file-name "share/emacs/site-lisp"
-                    (or profile guix-user-profile)))
-
 (defun guix-emacs-find-autoloads (directory)
   "Return a list of Emacs 'autoloads' files in DIRECTORY.
 The files in the list do not have extensions (.el, .elc)."
-  (cl-remove-duplicates
-   (delq nil
-        (mapcar (lambda (file)
-                  (when (string-match guix-emacs-autoloads-regexp file)
-                    (match-string 1 file)))
-                (directory-files directory 'full-name nil 'no-sort)))
-   :test #'string=))
-
-(defun guix-emacs-subdirs (directory)
-  "Return list of DIRECTORY subdirectories."
-  (cl-remove-if (lambda (file)
-                  (or (string-match-p (rx "/." string-end) file)
-                      (string-match-p (rx "/.." string-end) file)
-                      (not (file-directory-p file))))
-                (directory-files directory 'full-name nil 'no-sort)))
-
-(defun guix-emacs-directories (&optional profile)
-  "Return the list of directories under PROFILE that contain Emacs packages.
-This includes both `share/emacs/site-lisp/guix.d/PACKAGE'
-sub-directories and `share/emacs/site-lisp' itself.
-
-If PROFILE is nil, use `guix-user-profile'.
-Return nil, if Emacs packages are not installed in PROFILE."
-  (let ((root-dir (guix-emacs-directory (or profile guix-user-profile))))
-    (when (file-directory-p root-dir)
-      (let* ((pkgs-dir  (expand-file-name "guix.d" root-dir))
-             (pkgs-dirs (when (file-directory-p pkgs-dir)
-                          (guix-emacs-subdirs pkgs-dir))))
-        (cons root-dir pkgs-dirs)))))
+  ;; `directory-files' doesn't honor group in regexp.
+  (mapcar #'file-name-sans-extension
+          (directory-files directory 'full-name guix-emacs-autoloads-regexp)))
 
 ;;;###autoload
-(defun guix-emacs-autoload-packages (&rest profiles)
-  "Autoload Emacs packages installed in PROFILES.
-If PROFILES are not specified, use a default user and system
-profiles.
+(defun guix-emacs-autoload-packages ()
+  "Autoload Emacs packages found in EMACSLOADPATH.
 
-'Autoload' means add directories with Emacs packages to
-`load-path' and load 'autoloads' files matching
+'Autoload' means to load the 'autoloads' files matching
 `guix-emacs-autoloads-regexp'."
-  (interactive (list (if (fboundp 'guix-read-package-profile)
-                         (funcall 'guix-read-package-profile)
-                       guix-user-profile)))
-  (let* ((env      (getenv "GUIX_ENVIRONMENT"))
-         (profiles (or profiles
-                       (append (list "/run/current-system/profile"
-                                     guix-user-profile)
-                               (and env (list env))))))
-    (dolist (profile profiles)
-      (let ((dirs (guix-emacs-directories profile)))
-        (when dirs
-          (let* ((autoloads     (cl-mapcan #'guix-emacs-find-autoloads
-                                           dirs))
-                 (new-autoloads (cl-nset-difference autoloads
-                                                    guix-emacs-autoloads
-                                                    :test #'string=)))
-            (dolist (dir dirs)
-              (cl-pushnew (directory-file-name dir)
-                          load-path
-                          :test #'string=))
-            (dolist (file new-autoloads)
-              (load file 'noerror))
-            (setq guix-emacs-autoloads
-                  (append new-autoloads guix-emacs-autoloads))))))))
+  ;; FIXME: The autoloads generated by the emacs-build-system are not byte
+  ;; compiled.
+  (interactive)
+  (let* ((emacs-load-path (getenv "EMACSLOADPATH"))
+         (emacs-non-core-load-path-directories
+          ;; Filter out core Elisp directories, which are already autoloaded
+          ;; by Emacs.
+          (seq-filter (lambda (dir)
+                        (string-match-p "/share/emacs/site-lisp" dir))
+                      (split-string emacs-load-path ":")))
+          (autoloads (mapcan #'guix-emacs-find-autoloads
+                             emacs-non-core-load-path-directories)))
+    (mapc (lambda (f)
+            (load f 'noerror))
+          autoloads)))
 
 (provide 'guix-emacs)