Resurrect edebug-set-initial-mode, repurposing it to set the global mode.

lisp/emacs-lisp/edebug.el (edebug-initial-mode-alist): Uncomment, and
amend to match current modes and functions.
(edebug-set-initial-mode): Uncomment and change from setting a defun's
`edebug-initial-mode''s property to setting the variable
`edebug-initial-mode'.
(top level): Create new binding C-x C-a C-m for
`edebug-set-initial-mode'.

doc/lispref/edebug.texi (Edebug Execution Modes): document
`edebug-set-initial-mode' and its new key binding.
(Edebug Options): Mention the new command in the pertinent place.

etc/NEWS: Write entry for this change.

1 files changed, 28 insertions, 38 deletions

diff --git a/lisp/emacs-lisp/edebug.el b/lisp/emacs-lisp/edebug.el
index e437c587df4..a3e3b567cc4 100644
--- a/lisp/emacs-lisp/edebug.el
+++ b/lisp/emacs-lisp/edebug.el
@@ -3216,57 +3216,45 @@ This is useful for exiting even if `unwind-protect' code may be executed."
   (setq edebug-execution-mode 'Go-nonstop)
   (top-level))
 
-
 ;;(defun edebug-exit-out ()
 ;;  "Go until the current function exits."
 ;;  (interactive)
 ;;  (edebug-set-mode 'exiting "Exit..."))
 
-
-;;; The following initial mode setting definitions are not used yet.
-
-'(defconst edebug-initial-mode-alist
-  '((edebug-Continue-fast . Continue-fast)
-    (edebug-Trace-fast . Trace-fast)
-    (edebug-continue . continue)
-    (edebug-trace . trace)
-    (edebug-go . go)
-    (edebug-step-through . step)
-    (edebug-Go-nonstop . Go-nonstop)
-    )
+(defconst edebug-initial-mode-alist
+  '((edebug-step-mode . step)
+    (edebug-next-mode . next)
+    (edebug-trace-mode . trace)
+    (edebug-Trace-fast-mode . Trace-fast)
+    (edebug-go-mode . go)
+    (edebug-continue-mode . continue)
+    (edebug-Continue-fast-mode . Continue-fast)
+    (edebug-Go-nonstop-mode . Go-nonstop))
   "Association list between commands and the modes they set.")
 
+(defvar edebug-mode-map)                ; will be defined fully later.
 
-'(defun edebug-set-initial-mode ()
-  "Ask for the initial mode of the enclosing function.
+(defun edebug-set-initial-mode ()
+  "Set the initial execution mode of Edebug.
 The mode is requested via the key that would be used to set the mode in
 edebug-mode."
   (interactive)
-  (let* ((this-function (edebug-which-function))
-         (keymap (if (eq edebug-mode-map (current-local-map))
-                     edebug-mode-map))
-         (old-mode (or (get this-function 'edebug-initial-mode)
-                       edebug-initial-mode))
+  (let* ((old-mode edebug-initial-mode)
          (key (read-key-sequence
                (format
-                "Change initial edebug mode for %s from %s (%s) to (enter key): "
-                       this-function
-                       old-mode
-                       (where-is-internal
-                        (car (rassq old-mode edebug-initial-mode-alist))
-                        keymap 'firstonly
-                        ))))
-         (mode (cdr (assq (key-binding key) edebug-initial-mode-alist)))
-         )
-    (if (and mode
-             (or (get this-function 'edebug-initial-mode)
-                 (not (eq mode edebug-initial-mode))))
+                "Change initial edebug mode from %s (%c) to (enter key): "
+                old-mode
+                (aref (where-is-internal
+                       (car (rassq old-mode edebug-initial-mode-alist))
+                       edebug-mode-map 'firstonly)
+                      0))))
+         (mode (cdr (assq (lookup-key edebug-mode-map key)
+                          edebug-initial-mode-alist))))
+    (if mode
         (progn
-          (put this-function 'edebug-initial-mode mode)
-          (message "Initial mode for %s is now: %s"
-                   this-function mode))
-      (error "Key must map to one of the mode changing commands")
-      )))
+          (setq edebug-initial-mode mode)
+          (message "Edebug's initial mode is now: %s" mode))
+      (error "Key must map to one of the mode changing commands"))))
 
 ;;; Evaluation of expressions
 
@@ -3425,7 +3413,9 @@ be installed in `emacs-lisp-mode-map'.")
   (define-key emacs-lisp-mode-map "\C-x\C-a\C-s" 'edebug-step-mode)
   (define-key emacs-lisp-mode-map "\C-x\C-a\C-n" 'edebug-next-mode)
   (define-key emacs-lisp-mode-map "\C-x\C-a\C-c" 'edebug-go-mode)
-  (define-key emacs-lisp-mode-map "\C-x\C-a\C-l" 'edebug-where))
+  (define-key emacs-lisp-mode-map "\C-x\C-a\C-l" 'edebug-where)
+  ;; The following isn't a GUD binding.
+  (define-key emacs-lisp-mode-map "\C-x\C-a\C-m" 'edebug-set-initial-mode))
 
 (defvar edebug-mode-map
   (let ((map (copy-keymap emacs-lisp-mode-map)))