Lisp: Auto-generate SBCL core to speed up SLY startup.

.emacs.d/lisp/init-lisp.el

@@ -46,11 +46,44 @@
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Sly
+
+(defun dump-sbcl-core-for-sly ()        ; REVIEW: This probably works for SLIME too.
+  (cl-flet ((read-bytes (path)
+                        (with-temp-buffer
+                          ;; (set-buffer-multibyte nil)
+                          ;; (setq buffer-file-coding-system 'binary)
+                          (insert-file-contents-literally path)
+                          (buffer-substring-no-properties (point-min) (point-max)))))
+    (let* ((sbcl-core-dir (expand-file-name "sly/" user-emacs-directory))
+           (sbcl-core (expand-file-name "sbcl.core-for-sly" sbcl-core-dir))
+           (sbcl-core-version (expand-file-name "sbcl.version" sbcl-core-dir))
+           (current-sbcl-version (cadr (split-string
+                                        (with-temp-buffer
+                                          (call-process "sbcl" nil t nil "--version")
+                                          (buffer-string))))))
+      (when (or (not (file-exists-p sbcl-core-version))
+                (version< (car (split-string (read-bytes sbcl-core-version)))
+                          current-sbcl-version))
+        (make-directory sbcl-core-dir :parents)
+        (call-process
+         "sbcl" nil nil nil
+         "--eval" "(mapc 'require '(sb-bsd-sockets sb-posix sb-introspect sb-cltl2 asdf))"
+         "--eval" (format "(save-lisp-and-die %S)" sbcl-core))
+        (with-temp-file sbcl-core-version
+          (insert current-sbcl-version)))
+      (when (file-exists-p sbcl-core)
+        sbcl-core))))
+
 (with-eval-after-load 'sly
-  (setq sly-lisp-implementations
-        '((sbcl ("sbcl" "--noinform"))
-          (ccl ("ccl"))
-          (ecl ("ecl"))))
+  (let ((core (dump-sbcl-core-for-sly)))
+    (setq sly-lisp-implementations
+          `((sbcl ("sbcl"
+                   ,@(if core
+                         `("--core" ,core)
+                       '())))
+            ;; (sbcl ("sbcl" "--noinform"))
+            (ccl ("ccl"))
+            (ecl ("ecl")))))
   (with-eval-after-load 'sly-mrepl
     (setq sly-mrepl-history-file-name (expand-file-name "sly-mrepl-history" user-emacs-directory))
     (define-key sly-mrepl-mode-map (kbd "C-c M-o") 'sly-mrepl-clear-repl))