-;;; debug.el --- debuggers and related commands for Emacs
+;;; debug.el --- debuggers and related commands for Emacs -*- lexical-binding: t -*-
;; Copyright (C) 1985-1986, 1994, 2001-2013 Free Software Foundation,
;; Inc.
:group 'debugger
:version "24.3")
-(defvar debug-function-list nil
- "List of functions currently set for debug on entry.")
-
(defvar debugger-step-after-exit nil
"Non-nil means \"single-step\" after the debugger exits.")
;;;###autoload
(setq debugger 'debug)
;;;###autoload
-(defun debug (&rest debugger-args)
+(defun debug (&rest args)
"Enter debugger. \\<debugger-mode-map>`\\[debugger-continue]' returns from the debugger.
Arguments are mainly for use when this is called from the internals
of the evaluator.
(if (get-buffer "*Backtrace*")
(with-current-buffer (get-buffer "*Backtrace*")
(list major-mode (buffer-string)))))
+ (debugger-args args)
(debugger-buffer (get-buffer-create "*Backtrace*"))
(debugger-old-buffer (current-buffer))
(debugger-window nil)
(save-excursion
(when (eq (car debugger-args) 'debug)
;; Skip the frames for backtrace-debug, byte-code,
- ;; and implement-debug-on-entry.
- (backtrace-debug 3 t)
+ ;; debug--implement-debug-on-entry and the advice's `apply'.
+ (backtrace-debug 4 t)
;; Place an extra debug-on-exit for macro's.
- (when (eq 'lambda (car-safe (cadr (backtrace-frame 3))))
- (backtrace-debug 4 t)))
+ (when (eq 'lambda (car-safe (cadr (backtrace-frame 4))))
+ (backtrace-debug 5 t)))
(pop-to-buffer
debugger-buffer
`((display-buffer-reuse-window
(setq debug-on-next-call debugger-step-after-exit)
debugger-value)))
\f
-(defun debugger-setup-buffer (debugger-args)
+(defun debugger-setup-buffer (args)
"Initialize the `*Backtrace*' buffer for entry to the debugger.
That buffer should be current already."
(setq buffer-read-only nil)
(delete-region (point)
(progn
(search-forward "\n debug(")
- (forward-line (if (eq (car debugger-args) 'debug)
- 2 ; Remove implement-debug-on-entry frame.
+ (forward-line (if (eq (car args) 'debug)
+ ;; Remove debug--implement-debug-on-entry
+ ;; and the advice's `apply' frame.
+ 3
1))
(point)))
(insert "Debugger entered")
;; lambda is for debug-on-call when a function call is next.
;; debug is for debug-on-entry function called.
- (pcase (car debugger-args)
+ (pcase (car args)
((or `lambda `debug)
(insert "--entering a function:\n"))
;; Exiting a function.
(`exit
(insert "--returning value: ")
- (setq debugger-value (nth 1 debugger-args))
+ (setq debugger-value (nth 1 args))
(prin1 debugger-value (current-buffer))
(insert ?\n)
(delete-char 1)
;; Debugger entered for an error.
(`error
(insert "--Lisp error: ")
- (prin1 (nth 1 debugger-args) (current-buffer))
+ (prin1 (nth 1 args) (current-buffer))
(insert ?\n))
;; debug-on-call, when the next thing is an eval.
(`t
;; User calls debug directly.
(_
(insert ": ")
- (prin1 (if (eq (car debugger-args) 'nil)
- (cdr debugger-args) debugger-args)
+ (prin1 (if (eq (car args) 'nil)
+ (cdr args) args)
(current-buffer))
(insert ?\n)))
;; After any frame that uses eval-buffer,
(count 0))
(while (not (eq (cadr (backtrace-frame count)) 'debug))
(setq count (1+ count)))
- ;; Skip implement-debug-on-entry frame.
- (when (eq 'implement-debug-on-entry (cadr (backtrace-frame (1+ count))))
- (setq count (1+ count)))
+ ;; Skip debug--implement-debug-on-entry frame.
+ (when (eq 'debug--implement-debug-on-entry
+ (cadr (backtrace-frame (1+ count))))
+ (setq count (+ 2 count)))
(goto-char (point-min))
(when (looking-at "Debugger entered--\\(Lisp error\\|returning value\\):")
(goto-char (match-end 0))
:help "Continue to exit from this frame, with all debug-on-entry suspended"))
(define-key menu-map [deb-cont]
'(menu-item "Continue" debugger-continue
- :help "Continue, evaluating this expression without stopping"))
+ :help "Continue, evaluating this expression without stopping"))
(define-key menu-map [deb-step]
'(menu-item "Step through" debugger-step-through
- :help "Proceed, stepping through subexpressions of this expression"))
+ :help "Proceed, stepping through subexpressions of this expression"))
map))
(put 'debugger-mode 'mode-class 'special)
\f
;; When you change this, you may also need to change the number of
;; frames that the debugger skips.
-(defun implement-debug-on-entry ()
+(defun debug--implement-debug-on-entry (&rest _ignore)
"Conditionally call the debugger.
A call to this function is inserted by `debug-on-entry' to cause
functions to break on entry."
nil
(funcall debugger 'debug)))
-(defun debugger-special-form-p (symbol)
- "Return whether SYMBOL is a special form."
- (and (fboundp symbol)
- (subrp (symbol-function symbol))
- (eq (cdr (subr-arity (symbol-function symbol))) 'unevalled)))
-
;;;###autoload
(defun debug-on-entry (function)
"Request FUNCTION to invoke debugger each time it is called.
Redefining FUNCTION also cancels it."
(interactive
(let ((fn (function-called-at-point)) val)
- (when (debugger-special-form-p fn)
+ (when (special-form-p fn)
(setq fn nil))
(setq val (completing-read
(if fn
obarray
#'(lambda (symbol)
(and (fboundp symbol)
- (not (debugger-special-form-p symbol))))
+ (not (special-form-p symbol))))
t nil nil (symbol-name fn)))
(list (if (equal val "") fn (intern val)))))
- ;; FIXME: Use advice.el.
- (when (debugger-special-form-p function)
- (error "Function %s is a special form" function))
- (if (or (symbolp (symbol-function function))
- (subrp (symbol-function function)))
- ;; The function is built-in or aliased to another function.
- ;; Create a wrapper in which we can add the debug call.
- (fset function `(lambda (&rest debug-on-entry-args)
- ,(interactive-form (symbol-function function))
- (apply ',(symbol-function function)
- debug-on-entry-args)))
- (when (autoloadp (symbol-function function))
- ;; The function is autoloaded. Load its real definition.
- (autoload-do-load (symbol-function function) function))
- (when (or (not (consp (symbol-function function)))
- (and (eq (car (symbol-function function)) 'macro)
- (not (consp (cdr (symbol-function function))))))
- ;; The function is byte-compiled. Create a wrapper in which
- ;; we can add the debug call.
- (debug-convert-byte-code function)))
- (unless (consp (symbol-function function))
- (error "Definition of %s is not a list" function))
- (fset function (debug-on-entry-1 function t))
- (unless (memq function debug-function-list)
- (push function debug-function-list))
+ (advice-add function :before #'debug--implement-debug-on-entry)
function)
+(defun debug--function-list ()
+ "List of functions currently set for debug on entry."
+ (let ((funs '()))
+ (mapatoms
+ (lambda (s)
+ (when (advice-member-p #'debug--implement-debug-on-entry s)
+ (push s funs))))
+ funs))
+
;;;###autoload
(defun cancel-debug-on-entry (&optional function)
"Undo effect of \\[debug-on-entry] on FUNCTION.
(list (let ((name
(completing-read
"Cancel debug on entry to function (default all functions): "
- (mapcar 'symbol-name debug-function-list) nil t)))
+ (mapcar #'symbol-name (debug--function-list)) nil t)))
(when name
(unless (string= name "")
(intern name))))))
- (if (and function
- (not (string= function ""))) ; Pre 22.1 compatibility test.
+ (if function
(progn
- (let ((defn (debug-on-entry-1 function nil)))
- (condition-case nil
- (when (and (equal (nth 1 defn) '(&rest debug-on-entry-args))
- (eq (car (nth 3 defn)) 'apply))
- ;; `defn' is a wrapper introduced in debug-on-entry.
- ;; Get rid of it since we don't need it any more.
- (setq defn (nth 1 (nth 1 (nth 3 defn)))))
- (error nil))
- (fset function defn))
- (setq debug-function-list (delq function debug-function-list))
+ (advice-remove function #'debug--implement-debug-on-entry)
function)
(message "Cancelling debug-on-entry for all functions")
- (mapcar 'cancel-debug-on-entry debug-function-list)))
-
-(defun debug-arglist (definition)
- ;; FIXME: copied from ad-arglist.
- "Return the argument list of DEFINITION."
- (require 'help-fns)
- (help-function-arglist definition 'preserve-names))
-
-(defun debug-convert-byte-code (function)
- (let* ((defn (symbol-function function))
- (macro (eq (car-safe defn) 'macro)))
- (when macro (setq defn (cdr defn)))
- (when (byte-code-function-p defn)
- (let* ((args (debug-arglist defn))
- (body
- `((,(if (memq '&rest args) #'apply #'funcall)
- ,defn
- ,@(remq '&rest (remq '&optional args))))))
- (if (> (length defn) 5)
- ;; The mere presence of field 5 is sufficient to make
- ;; it interactive.
- (push `(interactive ,(aref defn 5)) body))
- (if (and (> (length defn) 4) (aref defn 4))
- ;; Use `documentation' here, to get the actual string,
- ;; in case the compiled function has a reference
- ;; to the .elc file.
- (setq body (cons (documentation function) body)))
- (setq defn `(closure (t) ,args ,@body)))
- (when macro (setq defn (cons 'macro defn)))
- (fset function defn))))
-
-(defun debug-on-entry-1 (function flag)
- (let* ((defn (symbol-function function))
- (tail defn))
- (when (eq (car-safe tail) 'macro)
- (setq tail (cdr tail)))
- (if (not (memq (car-safe tail) '(closure lambda)))
- ;; Only signal an error when we try to set debug-on-entry.
- ;; When we try to clear debug-on-entry, we are now done.
- (when flag
- (error "%s is not a user-defined Lisp function" function))
- (if (eq (car tail) 'closure) (setq tail (cdr tail)))
- (setq tail (cdr tail))
- ;; Skip the docstring.
- (when (and (stringp (cadr tail)) (cddr tail))
- (setq tail (cdr tail)))
- ;; Skip the interactive form.
- (when (eq 'interactive (car-safe (cadr tail)))
- (setq tail (cdr tail)))
- (unless (eq flag (equal (cadr tail) '(implement-debug-on-entry)))
- ;; Add/remove debug statement as needed.
- (setcdr tail (if flag
- (cons '(implement-debug-on-entry) (cdr tail))
- (cddr tail)))))
- defn))
+ (mapcar #'cancel-debug-on-entry (debug--function-list))))
(defun debugger-list-functions ()
"Display a list of all the functions now set to debug on entry."
(called-interactively-p 'interactive))
(with-output-to-temp-buffer (help-buffer)
(with-current-buffer standard-output
- (if (null debug-function-list)
- (princ "No debug-on-entry functions now\n")
- (princ "Functions set to debug on entry:\n\n")
- (dolist (fun debug-function-list)
- (make-text-button (point) (progn (prin1 fun) (point))
- 'type 'help-function
- 'help-args (list fun))
- (terpri))
- (terpri)
- (princ "Note: if you have redefined a function, then it may no longer\n")
- (princ "be set to debug on entry, even if it is in the list.")))))
+ (let ((funs (debug--function-list)))
+ (if (null funs)
+ (princ "No debug-on-entry functions now\n")
+ (princ "Functions set to debug on entry:\n\n")
+ (dolist (fun funs)
+ (make-text-button (point) (progn (prin1 fun) (point))
+ 'type 'help-function
+ 'help-args (list fun))
+ (terpri))
+ (terpri)
+ (princ "Note: if you have redefined a function, then it may no longer\n")
+ (princ "be set to debug on entry, even if it is in the list."))))))
(provide 'debug)