feat(cli): add -j/--jobs NUM options

To 'doom sync', 'doom upgrade', and 'doom build'. So users can decide
whether they want Doom 100%'ing their CPUs.

After 3.0, many of these commands will be merged, so a little code
duplication is fine for now.

core/cli/packages.el

@@ -17,12 +17,15 @@
 
 ;; DEPRECATED Replace with "doom sync --rebuild"
 (defcli! ((build b))
-    ((rebuild-p ("-r") "Only rebuild packages that need rebuilding"))
+    ((rebuild-p ("-r") "Only rebuild packages that need rebuilding")
+     (jobs      ("-j" "--jobs" num) "How many CPUs to use for native compilation"))
   "Byte-compiles & symlinks installed packages.
 
 This ensures that all needed files are symlinked from their package repo and
 their elisp files are byte-compiled. This is especially necessary if you upgrade
 Emacs (as byte-code is generally not forward-compatible)."
+  (when jobs
+    (setq native-comp-async-jobs-number (truncate jobs)))
   (when (doom-packages-build (not rebuild-p))
     (doom-autoloads-reload))
   t)

core/cli/sync.el

@@ -24,7 +24,8 @@
     ((noenvvar? ("-e") "Don't regenerate the envvar file")
      (noelc?    ("-c") "Don't recompile config")
      (update?   ("-u") "Update installed packages after syncing")
-     (purge?    ("-p") "Purge orphaned package repos & regraft them"))
+     (purge?    ("-p") "Purge orphaned package repos & regraft them")
+     (jobs      ("-j" "--jobs" num) "How many CPUs to use for native compilation"))
   "Synchronize your config with Doom Emacs.
 
 This is the equivalent of running autoremove, install, autoloads, then
@@ -37,10 +38,17 @@ recompile. Run this whenever you:
 
 It will ensure that unneeded packages are removed, all needed packages are
 installed, autoloads files are up-to-date and no byte-compiled files have gone
-stale."
+stale.
+
+OPTIONS:
+  -j, --jobs
+    Defaults to the maximum number of threads (or 1, if your CPU's threadcount
+    can't be determined)."
   :benchmark t
   (run-hooks 'doom-before-sync-hook)
   (add-hook 'kill-emacs-hook #'doom-sync--abort-warning-h)
+  (when jobs
+    (setq native-comp-async-jobs-number (truncate jobs)))
   (print! (start "Synchronizing your config with Doom Emacs..."))
   (unwind-protect
       (print-group!

core/cli/upgrade.el

@@ -20,6 +20,7 @@
 
 (defcli! ((upgrade up))
     ((packages?  ("-p" "--packages") "Only upgrade packages, not Doom")
+     (jobs       ("-j" "--jobs" num) "How many CPUs to use for native compilation")
      &context context)
   "Updates Doom and packages.
 
@@ -31,7 +32,7 @@ following shell commands:
     doom clean
     doom sync -u"
   (let* ((force? (doom-cli-context-suppress-prompts-p context))
-         (sync-cmd '("sync" "-u")))
+         (sync-cmd (append '("sync" "-u") (if jobs `("-j" ,num)))))
     (cond
      (packages?
       (call! sync-cmd)
@@ -41,7 +42,9 @@ following shell commands:
       ;; Reload Doom's CLI & libraries, in case there were any upstream changes.
       ;; Major changes will still break, however
       (print! (item "Reloading Doom Emacs"))
-      (exit! "doom" "upgrade" "-p" (if force? "--force")))
+      (exit! "doom" "upgrade" "-p"
+             (if force? "--force")
+             (if jobs (format "--jobs=%d" jobs))))
 
      ((print! "Doom is up-to-date!")
       (call! sync-cmd)))))