Extract make clean/clean-cache into elisp; new doom-etc-dir for non-volatile temp files

Makefile

@@ -21,11 +21,10 @@ compile: init.el clean
 	@$(EMACS) -l core/core.el -f 'doom/recompile'
 
 clean:
-	@rm -fv init.elc
-	@find {core,modules} -type f -iname '*.elc' -exec rm \-fv {} \;
+	@$(EMACS) -l core/core.el -f 'doom/clear-compiled'
 
 clean-cache:
-	@$(EMACS) -l core/core.el --eval '(delete-directory doom-cache-dir t)'
+	@$(EMACS) -l core/core.el -f 'doom/clear-cache'
 
 # This is only useful if your emacs.d is somewhere other than ~/.emacs.d (for
 # development purposes for instance).

core/core-packages.el

@@ -115,7 +115,7 @@ to speed up startup."
           package-activated-list nil)
 
     ;; Ensure core folders exist
-    (dolist (dir (list doom-local-dir doom-cache-dir package-user-dir))
+    (dolist (dir (list doom-local-dir doom-etc-dir doom-cache-dir package-user-dir))
       (unless (file-directory-p dir)
         (make-directory dir t)))
 
@@ -458,6 +458,22 @@ This may take a while."
         (message "\n%s" (mapconcat (lambda (file) (concat "+ ERROR: " (car file)))
                                    (nreverse errors) "\n"))))))
 
+(defun doom/clear-cache ()
+  "Clear local cache (`doom-cache-dir'). You may need to restart Emacs for some
+components to feel its effects."
+  (delete-directory doom-cache-dir t)
+  (make-directory doom-cache-dir t))
+
+(defun doom/clear-compiled ()
+  "Delete all compiled elc files in DOOM emacs, excluding compiled ELPA/QUELPA
+package files."
+  (interactive)
+  (when-let (elc-files (cl-remove-if (lambda (file) (file-in-directory-p file doom-local-dir))
+                                     (directory-files-recursively doom-emacs-dir "\\.elc$")))
+    (dolist (file elc-files)
+      (delete-file file)
+      (message "Deleting %s" (abbreviate-file-name file)))))
+
 
 ;;
 ;; Package.el modifications

core/core.el

@@ -32,17 +32,29 @@ line or use --debug-init to enable this.")
 (defvar doom-modules-dir (concat doom-emacs-dir "modules/")
   "Where configuration modules are stored.")
 
+
+;; Multi-host directories: I namespace `doom-etc-dir' and `doom-cache-dir' with
+;; host names because I use the same (often symlinked) emacs.d across several
+;; computers -- often simultaneously. Cache or other temporary files would
+;; conflict otherwise.
+
 (defvar doom-local-dir (concat doom-emacs-dir ".local/")
-  "Untracked directory for local Emacs files, including the cache
-(`doom-cache-dir'), packages (`doom-packages-dir') and autoloads file.")
+  "Root directory for local Emacs files.")
+
+(defvar doom-packages-dir (concat doom-local-dir "packages/")
+  "Where package.el and quelpa plugins (and their caches) are kept.")
+
+(defvar doom-etc-dir
+  (concat doom-local-dir "etc/" (system-name) "/")
+  "Hostname-based directory for non-volatile temporary files. These are not
+deleted or tampored with by DOOM functions. It should not be used for transient
+or unstable files.")
 
 (defvar doom-cache-dir
   (concat doom-local-dir "cache/" (system-name) "/")
-  "Hostname-based directory for temporary files.")
-
-(defvar doom-packages-dir
-  (concat doom-local-dir "packages/")
-  "Where package.el and quelpa plugins (and their caches) are kept.")
+  "Hostname-based directory for volatile temporary files. They are deleted when
+`doom/clear-cache' is called. For more stable local storage, use
+`doom-local-dir'.")
 
 (defvar doom-autoload-file
   (concat doom-local-dir "autoloads.el")
@@ -71,7 +83,7 @@ line or use --debug-init to enable this.")
  compilation-ask-about-save nil   ; save all buffers on `compile'
  compilation-scroll-output t
  confirm-nonexistent-file-or-buffer t
- custom-file (concat doom-cache-dir "custom.el")
+ custom-file (concat doom-etc-dir "custom.el")
  enable-recursive-minibuffers nil
  debug-on-error (and (not noninteractive) doom-debug-mode)
  idle-update-delay 1              ; update ui less often

modules/lang/cc/config.el

@@ -108,7 +108,7 @@
 (def-package! irony
   :after cc-mode
   :config
-  (setq irony-server-install-prefix (concat doom-cache-dir "irony-server/"))
+  (setq irony-server-install-prefix (concat doom-etc-dir "irony-server/"))
   (add-hook! 'irony-mode-hook '(irony-eldoc flycheck-mode))
   (add-hook! 'c++-mode-hook
     (make-local-variable 'irony-additional-clang-options)

modules/lang/java/config.el

@@ -8,7 +8,7 @@
   (set! :build 'compile-file    'java-mode 'meghanada-compile-file)
   (set! :build 'compile-project 'java-mode 'meghanada-compile-project)
 
-  (setq meghanada-server-install-dir (expand-file-name "meghanada-server/" doom-cache-dir)
+  (setq meghanada-server-install-dir (concat doom-etc-dir "meghanada-server/")
         meghanada-use-company t
         meghanada-use-flycheck t
         meghanada-use-auto-start t)

modules/lang/php/config.el

@@ -49,7 +49,7 @@
   :init
   (add-hook 'php-mode-hook 'eldoc-mode)
   :config
-  (setq php-extras-eldoc-functions-file (concat doom-cache-dir "php-extras-eldoc-functions"))
+  (setq php-extras-eldoc-functions-file (concat doom-etc-dir "php-extras-eldoc-functions"))
 
   ;; company will set up itself
   (advice-add 'php-extras-company-setup :override 'ignore)

modules/lang/python/config.el

@@ -30,7 +30,7 @@
   :init
   (add-hook 'python-mode-hook 'anaconda-mode)
   (add-hook 'anaconda-mode-hook 'anaconda-eldoc-mode)
-  (setq anaconda-mode-installation-directory (concat doom-cache-dir "anaconda/")
+  (setq anaconda-mode-installation-directory (concat doom-etc-dir "anaconda/")
         anaconda-mode-eldoc-as-single-line t)
 
   :config