Use XELB's debugging facilities

* exwm-debug.el: Move to XELB as `xcb-debug'.
* exwm-core.el (exwm--log): Use it.
(exwm--log): Support switching debugging output at runtime.

exwm-core.el

@@ -31,7 +31,7 @@
 (require 'xcb)
 (require 'xcb-icccm)
 (require 'xcb-ewmh)
-(require 'exwm-debug)
+(require 'xcb-debug)
 
 (defvar exwm--connection nil "X connection.")
 
@@ -68,21 +68,22 @@
 (declare-function exwm-workspace-move-window "exwm-workspace.el"
                   (frame-or-index &optional id))
 
+(defvar exwm-debug-on nil "Non-nil to turn on debug for EXWM.")
+
+(defmacro exwm--debug (&rest forms)
+  (when exwm-debug-on `(progn ,@forms)))
+
 (defmacro exwm--log (&optional format-string &rest objects)
   "Emit a message prepending the name of the function being executed.
 
 FORMAT-STRING is a string specifying the message to output, as in
 `format'.  The OBJECTS arguments specify the substitutions."
-  (when exwm-debug-on
-    (unless format-string (setq format-string ""))
-    `(progn
-       (exwm-debug--message (concat "%s:\t" ,format-string "\n")
-                            (exwm-debug--compile-time-function-name)
-                            ,@objects)
-       nil)))
-
-(defmacro exwm--debug (&rest forms)
-  (when exwm-debug-on `(progn ,@forms)))
+  (unless format-string (setq format-string ""))
+  `(when exwm-debug-on
+     (xcb-debug-message ,(concat "%s:\t" format-string "\n")
+                        (xcb-debug-compile-time-function-name)
+                        ,@objects)
+     nil))
 
 (defsubst exwm--id->buffer (id)
   "X window ID => Emacs buffer."
@@ -291,8 +292,8 @@ least SECS seconds later."
 
 (exwm--debug
   (let ((map exwm-mode-map))
-    (define-key map "\C-c\C-l" #'exwm-debug-clear)
-    (define-key map "\C-c\C-m" #'exwm-debug-mark)))
+    (define-key map "\C-c\C-l" #'xcb-debug-clear)
+    (define-key map "\C-c\C-m" #'xcb-debug-mark)))
 
 (define-derived-mode exwm-mode nil "EXWM"
   "Major mode for managing X windows.

exwm-debug.el

@@ -1,113 +0,0 @@
-;;; exwm-debug.el --- Debugging helpers for EXWM  -*- lexical-binding: t -*-
-
-;; Copyright (C) 2018 Free Software Foundation, Inc.
-
-;; Author: Adrián Medraño Calvo <adrian@medranocalvo.com>
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs is free software: you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation, either version 3 of the License, or
-;; (at your option) any later version.
-
-;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-;; GNU General Public License for more details.
-
-;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
-
-;;; Commentary:
-
-;; This module collects functions that help in debugging EXWM.
-
-;;; Code:
-
-(eval-and-compile
-  (defvar exwm-debug-on nil "Non-nil to turn on debug for EXWM."))
-
-(defvar exwm-debug-buffer "*EXWM-DEBUG*" "Buffer to write debug messages to.")
-
-(defvar exwm-debug-backtrace-start-frame 5
-  "From which frame to start collecting backtraces.")
-
-(defun exwm-debug--call-stack ()
-  "Return the current call stack frames."
-  (let (frames frame
-        ;; No need to acount for our setq, while, let, ...
-        (index exwm-debug-backtrace-start-frame))
-    (while (setq frame (backtrace-frame index))
-      (push frame frames)
-      (cl-incf index))
-    (cl-remove-if-not 'car frames)))
-
-(defmacro exwm-debug--compile-time-function-name ()
-  "Get the name of outermost definition at expansion time."
-  (let* ((frame (cl-find-if
-		 (lambda (frame)
-		   (ignore-errors
-		     (let ((clause (car (cl-third frame))))
-		       (or (equal clause 'defalias)
-			   (equal clause 'cl-defmethod)))))
-		 (reverse (exwm-debug--call-stack))))
-	 (defn (cl-third frame))
-	 (deftype (car defn)))
-    (cl-case deftype
-      ((defalias) (symbol-name (cl-cadadr defn)))
-      ((cl-defmethod) (symbol-name (cadr defn)))
-      (t "<unknown function>"))))
-
-(defmacro exwm-debug--with-debug-buffer (&rest forms)
-  "Evaluate FORMS making sure `exwm-debug-buffer' is correctly updated."
-  `(with-current-buffer (get-buffer-create exwm-debug-buffer)
-     (let (windows-eob)
-       ;; Note windows whose point is at EOB.
-       (dolist (w (get-buffer-window-list exwm-debug-buffer t t))
-         (when (= (window-point w) (point-max))
-           (push w windows-eob)))
-       (save-excursion
-         (goto-char (point-max))
-         ,@forms)
-       ;; Restore point.
-       (dolist (w windows-eob)
-         (set-window-point w (point-max))))))
-
-(defun exwm-debug--message (format-string &rest objects)
-  "Print a message to `exwm-debug-buffer'.
-
-The FORMAT-STRING argument follows the speficies how to print each of
-the passed OBJECTS.  See `format' for details."
-  (exwm-debug--with-debug-buffer
-   (insert (apply #'format format-string objects))))
-
-(defmacro exwm-debug--backtrace ()
-  "Print a backtrace to the `exwm-debug-buffer'."
-  '(exwm-debug--with-debug-buffer
-    (let ((standard-output exwm-debug-buffer))
-      (backtrace))))
-
-(defmacro exwm-debug--backtrace-on-error (&rest forms)
-  "Evaluate FORMS.  Printing a backtrace if an error is signaled."
-  `(let ((debug-on-error t)
-         (debugger (lambda (&rest _) (exwm-debug--backtrace))))
-     ,@forms))
-
-(defun exwm-debug-clear ()
-  "Clear the debug buffer."
-  (interactive)
-  (exwm-debug--with-debug-buffer
-   (erase-buffer)))
-
-(defun exwm-debug-mark ()
-  "Insert a mark in the debug buffer."
-  (interactive)
-  (exwm-debug--with-debug-buffer
-   (insert "\n")))
-
-
-
-(provide 'exwm-debug)
-
-;;; exwm-debug.el ends here