gdbmacs instance, s.t. can always run Emacs under gdb, and for Gnus

2 files changed, 53 insertions, 11 deletions

diff --git a/.emacs.d/eshell/profile b/.emacs.d/eshell/profile
index 59099604..42eb0e8a 100644
--- a/.emacs.d/eshell/profile
+++ b/.emacs.d/eshell/profile
@@ -1,7 +1,7 @@
 # for processes spawned by Eshell, drop the -c/-t set in ~/.shenv, so that the
-# Emacs frame containing Eshell gets reused
-export EDITOR=emacsclient
-export VISUAL=emacsclient
+# Emacs frame containing Eshell gets reused, and pass -s if necessary
+export EDITOR="emacsclient$(if (stringp (daemonp)) (concat \" -s\" (daemonp)) \"\")"
+export VISUAL="$EDITOR"
 
 # debconf will fall back to this frontend but emit a warning; set it ourselves
 # to avoid that warning
diff --git a/.emacs.d/init.el b/.emacs.d/init.el
index c85c779e..559ed09f 100644
--- a/.emacs.d/init.el
+++ b/.emacs.d/init.el
@@ -77,7 +77,10 @@
    ;; we're probably a shortlived instance of Emacs just to test something.
    ;; Set a different background colour to more easily distinguish frames
    ;; belonging to shortlived instances from those belonging to main instance.
-   `(,ws . ((background-color . ,(if (daemonp) "#FFFFF6" "alice blue"))))))
+   `(,ws
+     . ((background-color
+	 . ,(pcase (daemonp)
+	      ('nil "alice blue") ("gdbmacs" "honeydew") (_ "#FFFFF6")))))))
 
 (defun spw/maybe-scale-basic-faces (frame)
   "Entry for `window-size-change-functions' to increase font sizes
@@ -2233,6 +2236,43 @@ Called by '~/src/dotfiles/bin/emacsclient --spw/update-environment'."
 	(let ((slime-dispatching-connection connection))
 	  (slime-eval cl-form))))))
 
+(defvar-local spw/gdbmacs-target-emacs nil)
+
+(defun spw/gdbmacs-attach (pid)
+  (interactive "nEmacs PID: ")
+  (when-let ((proc (and (boundp 'gud-comint-buffer)
+			(get-buffer-process gud-comint-buffer))))
+    (if (string= gdb-inferior-status "signal-received")
+	;; Avoid wiping out useful info.
+	(error "Possibly Emacs just crashed; not attaching for now")
+      (set-process-query-on-exit-flag proc nil)
+      (kill-buffer gud-comint-buffer)))
+  (require 'gdb-mi)
+  (let ((default-directory (expand-file-name "~/src/emacs/")))
+    (gdb-reset)
+    (gdb (format "gdb -i=mi --pid=%d src/emacs" pid))
+    (setq spw/gdbmacs-target-emacs pid)
+    (gud-basic-call "continue")))
+
+(defun spw/remote-gdbmacs-attach ()
+  (interactive)
+  (call-process "emacsclient" nil "*gdbmacs-emacsclient*" nil
+		"--socket-name=gdbmacs" "--spw/installed"
+		"-e" (prin1-to-string `(spw/gdbmacs-attach ,(emacs-pid)))))
+
+(defun spw/maybe-remote-gdbmacs-attach ()
+  (when (and (eq (daemonp) t)
+	     (file-in-directory-p invocation-directory "~/src/emacs/"))
+    (spw/remote-gdbmacs-attach)))
+(add-hook 'after-init-hook #'spw/maybe-remote-gdbmacs-attach)
+
+;; C-c C-z to attempt to return control to the debugger.
+(defun spw/comint-stop-subjob (orig-fun)
+  (if spw/gdbmacs-target-emacs
+      (signal-process spw/gdbmacs-target-emacs 'SIGTSTP)
+    (funcall orig-fun)))
+(advice-add 'comint-stop-subjob :around #'spw/comint-stop-subjob)
+
 ;; open a frame on a new workspace with only the relevant dired buffer open,
 ;; eval this form: (global-set-key "\C-cG" #'spw/grading-advance)
 ;; and then use C-c G to open the first item (will need C-c f t after just
@@ -2678,13 +2718,15 @@ mutt's review view, after exiting EDITOR."
 (defvar gnus-always-read-dribble-file)
 
 (defun spw/gnus-startup-wrapper (orig-fun &rest args)
-  (if (and (daemonp) (file-directory-p "~/.fmail/")
-	   (not (file-exists-p "~/.newsrc.eld")))
-      (user-error "Must use dedicated Emacs for Gnus first run")
-    (let ((gc-cons-percentage 0.6)
-	  (gc-cons-threshold 402653184)
-	  (gnus-always-read-dribble-file (file-exists-p "~/.newsrc.eld")))
-      (apply orig-fun args))))
+  (when-let ((daemon (and (file-directory-p "~/.fmail/") (daemonp))))
+    (unless (file-exists-p "~/.newsrc.eld")
+      (user-error "Must use dedicated Emacs for Gnus first run"))
+    (unless (string= "gdbmacs" daemon)
+      (user-error "This is not the Gnusmacs you're looking for")))
+  (let ((gc-cons-percentage 0.6)
+	(gc-cons-threshold 402653184)
+	(gnus-always-read-dribble-file (file-exists-p "~/.newsrc.eld")))
+    (apply orig-fun args)))
 (advice-add 'gnus :around #'spw/gnus-startup-wrapper)
 (advice-add 'gnus-no-server :around #'spw/gnus-startup-wrapper)