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854 lines
31 KiB
EmacsLisp
854 lines
31 KiB
EmacsLisp
;;; debug.el --- debuggers and related commands for Emacs -*- lexical-binding: t -*-
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;; Copyright (C) 1985-1986, 1994, 2001-2016 Free Software Foundation,
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;; Inc.
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;; Maintainer: emacs-devel@gnu.org
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;; Keywords: lisp, tools, maint
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
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;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
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;;; Commentary:
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;; This is a major mode documented in the Emacs Lisp manual.
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;;; Code:
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(require 'button)
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(defgroup debugger nil
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"Debuggers and related commands for Emacs."
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:prefix "debugger-"
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:group 'debug)
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(defcustom debugger-mode-hook nil
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"Hooks run when `debugger-mode' is turned on."
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:type 'hook
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:group 'debugger
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:version "20.3")
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(defcustom debugger-batch-max-lines 40
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"Maximum lines to show in debugger buffer in a noninteractive Emacs.
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When the debugger is entered and Emacs is running in batch mode,
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if the backtrace text has more than this many lines,
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the middle is discarded, and just the beginning and end are displayed."
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:type 'integer
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:group 'debugger
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:version "21.1")
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(defcustom debugger-bury-or-kill 'bury
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"What to do with the debugger buffer when exiting `debug'.
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The value affects the behavior of operations on any window
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previously showing the debugger buffer.
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nil means that if its window is not deleted when exiting the
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debugger, invoking `switch-to-prev-buffer' will usually show
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the debugger buffer again.
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`append' means that if the window is not deleted, the debugger
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buffer moves to the end of the window's previous buffers so
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it's less likely that a future invocation of
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`switch-to-prev-buffer' will switch to it. Also, it moves the
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buffer to the end of the frame's buffer list.
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`bury' means that if the window is not deleted, its buffer is
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removed from the window's list of previous buffers. Also, it
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moves the buffer to the end of the frame's buffer list. This
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value provides the most reliable remedy to not have
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`switch-to-prev-buffer' switch to the debugger buffer again
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without killing the buffer.
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`kill' means to kill the debugger buffer.
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The value used here is passed to `quit-restore-window'."
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:type '(choice
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(const :tag "Keep alive" nil)
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(const :tag "Append" append)
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(const :tag "Bury" bury)
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(const :tag "Kill" kill))
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:group 'debugger
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:version "24.3")
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(defvar debugger-step-after-exit nil
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"Non-nil means \"single-step\" after the debugger exits.")
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(defvar debugger-value nil
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"This is the value for the debugger to return, when it returns.")
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(defvar debugger-old-buffer nil
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"This is the buffer that was current when the debugger was entered.")
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(defvar debugger-previous-window nil
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"This is the window last showing the debugger buffer.")
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(defvar debugger-previous-window-height nil
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"The last recorded height of `debugger-previous-window'.")
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(defvar debugger-previous-backtrace nil
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"The contents of the previous backtrace (including text properties).
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This is to optimize `debugger-make-xrefs'.")
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(defvar debugger-outer-match-data)
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(defvar debugger-will-be-back nil
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"Non-nil if we expect to get back in the debugger soon.")
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(defvar inhibit-debug-on-entry nil
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"Non-nil means that `debug-on-entry' is disabled.")
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(defvar debugger-jumping-flag nil
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"Non-nil means that `debug-on-entry' is disabled.
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This variable is used by `debugger-jump', `debugger-step-through',
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and `debugger-reenable' to temporarily disable debug-on-entry.")
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(defvar inhibit-trace) ;Not yet implemented.
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(defvar debugger-args nil
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"Arguments with which the debugger was called.
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It is a list expected to take the form (CAUSE . REST)
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where CAUSE can be:
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- debug: called for entry to a flagged function.
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- t: called because of debug-on-next-call.
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- lambda: same thing but via `funcall'.
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- exit: called because of exit of a flagged function.
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- error: called because of `debug-on-error'.")
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;;;###autoload
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(setq debugger 'debug)
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;;;###autoload
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(defun debug (&rest args)
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"Enter debugger. \\<debugger-mode-map>`\\[debugger-continue]' returns from the debugger.
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Arguments are mainly for use when this is called from the internals
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of the evaluator.
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You may call with no args, or you may pass nil as the first arg and
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any other args you like. In that case, the list of args after the
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first will be printed into the backtrace buffer."
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(interactive)
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(if inhibit-redisplay
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;; Don't really try to enter debugger within an eval from redisplay.
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debugger-value
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(unless noninteractive
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(message "Entering debugger..."))
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(let (debugger-value
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(debugger-previous-state
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(if (get-buffer "*Backtrace*")
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(with-current-buffer (get-buffer "*Backtrace*")
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(list major-mode (buffer-string)))))
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(debugger-args args)
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(debugger-buffer (get-buffer-create "*Backtrace*"))
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(debugger-old-buffer (current-buffer))
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(debugger-window nil)
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(debugger-step-after-exit nil)
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(debugger-will-be-back nil)
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;; Don't keep reading from an executing kbd macro!
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(executing-kbd-macro nil)
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;; Save the outer values of these vars for the `e' command
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;; before we replace the values.
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(debugger-outer-match-data (match-data))
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(debugger-with-timeout-suspend (with-timeout-suspend)))
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;; Set this instead of binding it, so that `q'
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;; will not restore it.
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(setq overriding-terminal-local-map nil)
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;; Don't let these magic variables affect the debugger itself.
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(let ((last-command nil) this-command track-mouse
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(inhibit-trace t)
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unread-command-events
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unread-post-input-method-events
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last-input-event last-command-event last-nonmenu-event
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last-event-frame
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overriding-local-map
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load-read-function
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;; If we are inside a minibuffer, allow nesting
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;; so that we don't get an error from the `e' command.
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(enable-recursive-minibuffers
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(or enable-recursive-minibuffers (> (minibuffer-depth) 0)))
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(standard-input t) (standard-output t)
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inhibit-redisplay
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(cursor-in-echo-area nil)
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(window-configuration (current-window-configuration)))
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(unwind-protect
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(save-excursion
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(when (eq (car debugger-args) 'debug)
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;; Skip the frames for backtrace-debug, byte-code,
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;; debug--implement-debug-on-entry and the advice's `apply'.
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(backtrace-debug 4 t)
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;; Place an extra debug-on-exit for macro's.
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(when (eq 'lambda (car-safe (cadr (backtrace-frame 4))))
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(backtrace-debug 5 t)))
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(pop-to-buffer
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debugger-buffer
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`((display-buffer-reuse-window
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display-buffer-in-previous-window)
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. (,(when (and (window-live-p debugger-previous-window)
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(frame-visible-p
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(window-frame debugger-previous-window)))
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`(previous-window . ,debugger-previous-window)))))
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(setq debugger-window (selected-window))
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(if (eq debugger-previous-window debugger-window)
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(when debugger-jumping-flag
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;; Try to restore previous height of debugger
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;; window.
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(condition-case nil
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(window-resize
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debugger-window
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(- debugger-previous-window-height
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(window-total-height debugger-window)))
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(error nil)))
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(setq debugger-previous-window debugger-window))
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(debugger-mode)
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(debugger-setup-buffer debugger-args)
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(when noninteractive
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;; If the backtrace is long, save the beginning
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;; and the end, but discard the middle.
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(when (> (count-lines (point-min) (point-max))
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debugger-batch-max-lines)
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(goto-char (point-min))
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(forward-line (/ 2 debugger-batch-max-lines))
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(let ((middlestart (point)))
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(goto-char (point-max))
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(forward-line (- (/ 2 debugger-batch-max-lines)
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debugger-batch-max-lines))
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(delete-region middlestart (point)))
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(insert "...\n"))
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(goto-char (point-min))
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(message "%s" (buffer-string))
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(kill-emacs -1))
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(message "")
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(let ((standard-output nil)
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(buffer-read-only t))
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(message "")
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;; Make sure we unbind buffer-read-only in the right buffer.
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(save-excursion
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(recursive-edit))))
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(when (and (window-live-p debugger-window)
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(eq (window-buffer debugger-window) debugger-buffer))
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;; Record height of debugger window.
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(setq debugger-previous-window-height
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(window-total-height debugger-window)))
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(if debugger-will-be-back
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;; Restore previous window configuration (Bug#12623).
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(set-window-configuration window-configuration)
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(when (and (window-live-p debugger-window)
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(eq (window-buffer debugger-window) debugger-buffer))
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(progn
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;; Unshow debugger-buffer.
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(quit-restore-window debugger-window debugger-bury-or-kill)
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;; Restore current buffer (Bug#12502).
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(set-buffer debugger-old-buffer))))
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;; Restore previous state of debugger-buffer in case we were
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;; in a recursive invocation of the debugger, otherwise just
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;; erase the buffer and put it into fundamental mode.
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(when (buffer-live-p debugger-buffer)
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(with-current-buffer debugger-buffer
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(let ((inhibit-read-only t))
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(erase-buffer)
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(if (null debugger-previous-state)
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(fundamental-mode)
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(insert (nth 1 debugger-previous-state))
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(funcall (nth 0 debugger-previous-state))))))
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(with-timeout-unsuspend debugger-with-timeout-suspend)
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(set-match-data debugger-outer-match-data)))
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(setq debug-on-next-call debugger-step-after-exit)
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debugger-value)))
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(defun debugger-setup-buffer (args)
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"Initialize the `*Backtrace*' buffer for entry to the debugger.
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That buffer should be current already."
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(setq buffer-read-only nil)
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(erase-buffer)
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(set-buffer-multibyte t) ;Why was it nil ? -stef
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(setq buffer-undo-list t)
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(let ((standard-output (current-buffer))
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(print-escape-newlines t)
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(print-level 8)
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(print-length 50))
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(backtrace))
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(goto-char (point-min))
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(delete-region (point)
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(progn
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(search-forward "\n debug(")
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(forward-line (if (eq (car args) 'debug)
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;; Remove debug--implement-debug-on-entry
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;; and the advice's `apply' frame.
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3
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1))
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(point)))
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(insert "Debugger entered")
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;; lambda is for debug-on-call when a function call is next.
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;; debug is for debug-on-entry function called.
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(let ((pos (point)))
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(pcase (car args)
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((or `lambda `debug)
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(insert "--entering a function:\n")
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(setq pos (1- (point))))
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;; Exiting a function.
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(`exit
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(insert "--returning value: ")
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(setq pos (point))
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(setq debugger-value (nth 1 args))
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(prin1 debugger-value (current-buffer))
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(insert ?\n)
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(delete-char 1)
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(insert ? )
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(beginning-of-line))
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;; Debugger entered for an error.
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(`error
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(insert "--Lisp error: ")
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(setq pos (point))
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(prin1 (nth 1 args) (current-buffer))
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(insert ?\n))
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;; debug-on-call, when the next thing is an eval.
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(`t
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(insert "--beginning evaluation of function call form:\n")
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(setq pos (1- (point))))
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;; User calls debug directly.
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(_
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(insert ": ")
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(setq pos (point))
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(prin1 (if (eq (car args) 'nil)
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(cdr args) args)
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(current-buffer))
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(insert ?\n)))
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;; Place point on "stack frame 0" (bug#15101).
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(goto-char pos))
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;; After any frame that uses eval-buffer,
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;; insert a line that states the buffer position it's reading at.
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(save-excursion
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(let ((tem eval-buffer-list))
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(while (and tem
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(re-search-forward "^ eval-\\(buffer\\|region\\)(" nil t))
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(end-of-line)
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(insert (format " ; Reading at buffer position %d"
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;; This will get the wrong result
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;; if there are two nested eval-region calls
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;; for the same buffer. That's not a very useful case.
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(with-current-buffer (car tem)
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(point))))
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(pop tem))))
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(debugger-make-xrefs))
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(defun debugger-make-xrefs (&optional buffer)
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"Attach cross-references to function names in the `*Backtrace*' buffer."
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(interactive "b")
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(with-current-buffer (or buffer (current-buffer))
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(save-excursion
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(setq buffer (current-buffer))
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(let ((inhibit-read-only t)
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(old-end (point-min)) (new-end (point-min)))
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;; If we saved an old backtrace, find the common part
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;; between the new and the old.
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;; Compare line by line, starting from the end,
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;; because that's the part that is likely to be unchanged.
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(if debugger-previous-backtrace
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(let (old-start new-start (all-match t))
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(goto-char (point-max))
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(with-temp-buffer
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(insert debugger-previous-backtrace)
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(while (and all-match (not (bobp)))
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(setq old-end (point))
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(forward-line -1)
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(setq old-start (point))
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(with-current-buffer buffer
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(setq new-end (point))
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(forward-line -1)
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(setq new-start (point)))
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(if (not (zerop
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(let ((case-fold-search nil))
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(compare-buffer-substrings
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(current-buffer) old-start old-end
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buffer new-start new-end))))
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(setq all-match nil))))
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;; Now new-end is the position of the start of the
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;; unchanged part in the current buffer, and old-end is
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;; the position of that same text in the saved old
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;; backtrace. But we must subtract (point-min) since strings are
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;; indexed in origin 0.
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;; Replace the unchanged part of the backtrace
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;; with the text from debugger-previous-backtrace,
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;; since that already has the proper xrefs.
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;; With this optimization, we only need to scan
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;; the changed part of the backtrace.
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(delete-region new-end (point-max))
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(goto-char (point-max))
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(insert (substring debugger-previous-backtrace
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(- old-end (point-min))))
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;; Make the unchanged part of the backtrace inaccessible
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;; so it won't be scanned.
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(narrow-to-region (point-min) new-end)))
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;; Scan the new part of the backtrace, inserting xrefs.
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(goto-char (point-min))
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(while (progn
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(goto-char (+ (point) 2))
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(skip-syntax-forward "^w_")
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(not (eobp)))
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(let* ((beg (point))
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(end (progn (skip-syntax-forward "w_") (point)))
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(sym (intern-soft (buffer-substring-no-properties
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beg end)))
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(file (and sym (symbol-file sym 'defun))))
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(when file
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(goto-char beg)
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;; help-xref-button needs to operate on something matched
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;; by a regexp, so set that up for it.
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(re-search-forward "\\(\\sw\\|\\s_\\)+")
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(help-xref-button 0 'help-function-def sym file)))
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(forward-line 1))
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(widen))
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(setq debugger-previous-backtrace (buffer-string)))))
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(defun debugger-step-through ()
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"Proceed, stepping through subexpressions of this expression.
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Enter another debugger on next entry to eval, apply or funcall."
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(interactive)
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(setq debugger-step-after-exit t)
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(setq debugger-jumping-flag t)
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(setq debugger-will-be-back t)
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(add-hook 'post-command-hook 'debugger-reenable)
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(message "Proceeding, will debug on next eval or call.")
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(exit-recursive-edit))
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(defun debugger-continue ()
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"Continue, evaluating this expression without stopping."
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(interactive)
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(unless debugger-may-continue
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(error "Cannot continue"))
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(message "Continuing.")
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(save-excursion
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;; Check to see if we've flagged some frame for debug-on-exit, in which
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;; case we'll probably come back to the debugger soon.
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(goto-char (point-min))
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(if (re-search-forward "^\\* " nil t)
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(setq debugger-will-be-back t)))
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(exit-recursive-edit))
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(defun debugger-return-value (val)
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"Continue, specifying value to return.
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This is only useful when the value returned from the debugger
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will be used, such as in a debug on exit from a frame."
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(interactive "XReturn value (evaluated): ")
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(when (memq (car debugger-args) '(t lambda error debug))
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(error "Cannot return a value %s"
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(if (eq (car debugger-args) 'error)
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"from an error" "at function entrance")))
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(setq debugger-value val)
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(princ "Returning " t)
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(prin1 debugger-value)
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(save-excursion
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;; Check to see if we've flagged some frame for debug-on-exit, in which
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;; case we'll probably come back to the debugger soon.
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(goto-char (point-min))
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(if (re-search-forward "^\\* " nil t)
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(setq debugger-will-be-back t)))
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(exit-recursive-edit))
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(defun debugger-jump ()
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"Continue to exit from this frame, with all debug-on-entry suspended."
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(interactive)
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(debugger-frame)
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(setq debugger-jumping-flag t)
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(add-hook 'post-command-hook 'debugger-reenable)
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(message "Continuing through this frame")
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(setq debugger-will-be-back t)
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(exit-recursive-edit))
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|
||
(defun debugger-reenable ()
|
||
"Turn all debug-on-entry functions back on.
|
||
This function is put on `post-command-hook' by `debugger-jump' and
|
||
removes itself from that hook."
|
||
(setq debugger-jumping-flag nil)
|
||
(remove-hook 'post-command-hook 'debugger-reenable))
|
||
|
||
(defun debugger-frame-number (&optional skip-base)
|
||
"Return number of frames in backtrace before the one point points at."
|
||
(save-excursion
|
||
(beginning-of-line)
|
||
(if (looking-at " *;;;\\|[a-z]")
|
||
(error "This line is not a function call"))
|
||
(let ((opoint (point))
|
||
(count 0))
|
||
(unless skip-base
|
||
(while (not (eq (cadr (backtrace-frame count)) 'debug))
|
||
(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))
|
||
(forward-sexp 1))
|
||
(forward-line 1)
|
||
(while (progn
|
||
(forward-char 2)
|
||
(cond ((debugger--locals-visible-p)
|
||
(goto-char (next-single-char-property-change
|
||
(point) 'locals-visible)))
|
||
((= (following-char) ?\()
|
||
(forward-sexp 1))
|
||
(t
|
||
(forward-sexp 2)))
|
||
(forward-line 1)
|
||
(<= (point) opoint))
|
||
(if (looking-at " *;;;")
|
||
(forward-line 1))
|
||
(setq count (1+ count)))
|
||
count)))
|
||
|
||
(defun debugger-frame ()
|
||
"Request entry to debugger when this frame exits.
|
||
Applies to the frame whose line point is on in the backtrace."
|
||
(interactive)
|
||
(backtrace-debug (debugger-frame-number) t)
|
||
(beginning-of-line)
|
||
(if (= (following-char) ? )
|
||
(let ((inhibit-read-only t))
|
||
(delete-char 1)
|
||
(insert ?*)))
|
||
(beginning-of-line))
|
||
|
||
(defun debugger-frame-clear ()
|
||
"Do not enter debugger when this frame exits.
|
||
Applies to the frame whose line point is on in the backtrace."
|
||
(interactive)
|
||
(backtrace-debug (debugger-frame-number) nil)
|
||
(beginning-of-line)
|
||
(if (= (following-char) ?*)
|
||
(let ((inhibit-read-only t))
|
||
(delete-char 1)
|
||
(insert ? )))
|
||
(beginning-of-line))
|
||
|
||
(defmacro debugger-env-macro (&rest body)
|
||
"Run BODY in original environment."
|
||
(declare (indent 0))
|
||
`(progn
|
||
(set-match-data debugger-outer-match-data)
|
||
(prog1
|
||
(progn ,@body)
|
||
(setq debugger-outer-match-data (match-data)))))
|
||
|
||
(defun debugger--backtrace-base ()
|
||
"Return the function name that marks the top of the backtrace.
|
||
See `backtrace-frame'."
|
||
(cond ((eq 'debug--implement-debug-on-entry
|
||
(cadr (backtrace-frame 1 'debug)))
|
||
'debug--implement-debug-on-entry)
|
||
(t 'debug)))
|
||
|
||
(defun debugger-eval-expression (exp &optional nframe)
|
||
"Eval an expression, in an environment like that outside the debugger.
|
||
The environment used is the one when entering the activation frame at point."
|
||
(interactive
|
||
(list (read--expression "Eval in stack frame: ")))
|
||
(let ((nframe (or nframe
|
||
(condition-case nil (1+ (debugger-frame-number 'skip-base))
|
||
(error 0)))) ;; If on first line.
|
||
(base (debugger--backtrace-base)))
|
||
(debugger-env-macro
|
||
(let ((val (backtrace-eval exp nframe base)))
|
||
(prog1
|
||
(prin1 val t)
|
||
(let ((str (eval-expression-print-format val)))
|
||
(if str (princ str t))))))))
|
||
|
||
(defun debugger--locals-visible-p ()
|
||
"Are the local variables of the current stack frame visible?"
|
||
(save-excursion
|
||
(move-to-column 2)
|
||
(get-text-property (point) 'locals-visible)))
|
||
|
||
(defun debugger--insert-locals (locals)
|
||
"Insert the local variables LOCALS at point."
|
||
(cond ((null locals)
|
||
(insert "\n [no locals]"))
|
||
(t
|
||
(let ((print-escape-newlines t))
|
||
(dolist (s+v locals)
|
||
(let ((symbol (car s+v))
|
||
(value (cdr s+v)))
|
||
(insert "\n ")
|
||
(prin1 symbol (current-buffer))
|
||
(insert " = ")
|
||
(prin1 value (current-buffer))))))))
|
||
|
||
(defun debugger--show-locals ()
|
||
"For the frame at point, insert locals and add text properties."
|
||
(let* ((nframe (1+ (debugger-frame-number 'skip-base)))
|
||
(base (debugger--backtrace-base))
|
||
(locals (backtrace--locals nframe base))
|
||
(inhibit-read-only t))
|
||
(save-excursion
|
||
(let ((start (progn
|
||
(move-to-column 2)
|
||
(point))))
|
||
(end-of-line)
|
||
(debugger--insert-locals locals)
|
||
(add-text-properties start (point) '(locals-visible t))))))
|
||
|
||
(defun debugger--hide-locals ()
|
||
"Delete local variables and remove the text property."
|
||
(let* ((col (current-column))
|
||
(end (progn
|
||
(move-to-column 2)
|
||
(next-single-char-property-change (point) 'locals-visible)))
|
||
(start (previous-single-char-property-change end 'locals-visible))
|
||
(inhibit-read-only t))
|
||
(remove-text-properties start end '(locals-visible))
|
||
(goto-char start)
|
||
(end-of-line)
|
||
(delete-region (point) end)
|
||
(move-to-column col)))
|
||
|
||
(defun debugger-toggle-locals ()
|
||
"Show or hide local variables of the current stack frame."
|
||
(interactive)
|
||
(cond ((debugger--locals-visible-p)
|
||
(debugger--hide-locals))
|
||
(t
|
||
(debugger--show-locals))))
|
||
|
||
|
||
(defvar debugger-mode-map
|
||
(let ((map (make-keymap))
|
||
(menu-map (make-sparse-keymap)))
|
||
(set-keymap-parent map button-buffer-map)
|
||
(suppress-keymap map)
|
||
(define-key map "-" 'negative-argument)
|
||
(define-key map "b" 'debugger-frame)
|
||
(define-key map "c" 'debugger-continue)
|
||
(define-key map "j" 'debugger-jump)
|
||
(define-key map "r" 'debugger-return-value)
|
||
(define-key map "u" 'debugger-frame-clear)
|
||
(define-key map "d" 'debugger-step-through)
|
||
(define-key map "l" 'debugger-list-functions)
|
||
(define-key map "h" 'describe-mode)
|
||
(define-key map "q" 'top-level)
|
||
(define-key map "e" 'debugger-eval-expression)
|
||
(define-key map "v" 'debugger-toggle-locals) ; "v" is for "variables".
|
||
(define-key map " " 'next-line)
|
||
(define-key map "R" 'debugger-record-expression)
|
||
(define-key map "\C-m" 'debug-help-follow)
|
||
(define-key map [mouse-2] 'push-button)
|
||
(define-key map [menu-bar debugger] (cons "Debugger" menu-map))
|
||
(define-key menu-map [deb-top]
|
||
'(menu-item "Quit" top-level
|
||
:help "Quit debugging and return to top level"))
|
||
(define-key menu-map [deb-s0] '("--"))
|
||
(define-key menu-map [deb-descr]
|
||
'(menu-item "Describe Debugger Mode" describe-mode
|
||
:help "Display documentation for debugger-mode"))
|
||
(define-key menu-map [deb-hfol]
|
||
'(menu-item "Help Follow" debug-help-follow
|
||
:help "Follow cross-reference"))
|
||
(define-key menu-map [deb-nxt]
|
||
'(menu-item "Next Line" next-line
|
||
:help "Move cursor down"))
|
||
(define-key menu-map [deb-s1] '("--"))
|
||
(define-key menu-map [deb-lfunc]
|
||
'(menu-item "List debug on entry functions" debugger-list-functions
|
||
:help "Display a list of all the functions now set to debug on entry"))
|
||
(define-key menu-map [deb-fclear]
|
||
'(menu-item "Cancel debug frame" debugger-frame-clear
|
||
:help "Do not enter debugger when this frame exits"))
|
||
(define-key menu-map [deb-frame]
|
||
'(menu-item "Debug frame" debugger-frame
|
||
:help "Request entry to debugger when this frame exits"))
|
||
(define-key menu-map [deb-s2] '("--"))
|
||
(define-key menu-map [deb-ret]
|
||
'(menu-item "Return value..." debugger-return-value
|
||
:help "Continue, specifying value to return."))
|
||
(define-key menu-map [deb-rec]
|
||
'(menu-item "Display and Record Expression" debugger-record-expression
|
||
:help "Display a variable's value and record it in `*Backtrace-record*' buffer"))
|
||
(define-key menu-map [deb-eval]
|
||
'(menu-item "Eval Expression..." debugger-eval-expression
|
||
:help "Eval an expression, in an environment like that outside the debugger"))
|
||
(define-key menu-map [deb-jump]
|
||
'(menu-item "Jump" debugger-jump
|
||
: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"))
|
||
(define-key menu-map [deb-step]
|
||
'(menu-item "Step through" debugger-step-through
|
||
:help "Proceed, stepping through subexpressions of this expression"))
|
||
map))
|
||
|
||
(put 'debugger-mode 'mode-class 'special)
|
||
|
||
(define-derived-mode debugger-mode fundamental-mode "Debugger"
|
||
"Mode for backtrace buffers, selected in debugger.
|
||
\\<debugger-mode-map>
|
||
A line starts with `*' if exiting that frame will call the debugger.
|
||
Type \\[debugger-frame] or \\[debugger-frame-clear] to set or remove the `*'.
|
||
|
||
When in debugger due to frame being exited,
|
||
use the \\[debugger-return-value] command to override the value
|
||
being returned from that frame.
|
||
|
||
Use \\[debug-on-entry] and \\[cancel-debug-on-entry] to control
|
||
which functions will enter the debugger when called.
|
||
|
||
Complete list of commands:
|
||
\\{debugger-mode-map}"
|
||
(setq truncate-lines t)
|
||
(set-syntax-table emacs-lisp-mode-syntax-table)
|
||
(use-local-map debugger-mode-map))
|
||
|
||
(defcustom debugger-record-buffer "*Debugger-record*"
|
||
"Buffer name for expression values, for \\[debugger-record-expression]."
|
||
:type 'string
|
||
:group 'debugger
|
||
:version "20.3")
|
||
|
||
(defun debugger-record-expression (exp)
|
||
"Display a variable's value and record it in `*Backtrace-record*' buffer."
|
||
(interactive
|
||
(list (read--expression "Record Eval: ")))
|
||
(let* ((buffer (get-buffer-create debugger-record-buffer))
|
||
(standard-output buffer))
|
||
(princ (format "Debugger Eval (%s): " exp))
|
||
(princ (debugger-eval-expression exp))
|
||
(terpri))
|
||
|
||
(with-current-buffer (get-buffer debugger-record-buffer)
|
||
(message "%s"
|
||
(buffer-substring (line-beginning-position 0)
|
||
(line-end-position 0)))))
|
||
|
||
(defun debug-help-follow (&optional pos)
|
||
"Follow cross-reference at POS, defaulting to point.
|
||
|
||
For the cross-reference format, see `help-make-xrefs'."
|
||
(interactive "d")
|
||
;; Ideally we'd just do (call-interactively 'help-follow) except that this
|
||
;; assumes we're already in a *Help* buffer and reuses it, so it ends up
|
||
;; incorrectly "reusing" the *Backtrace* buffer to show the help info.
|
||
(unless pos
|
||
(setq pos (point)))
|
||
(unless (push-button pos)
|
||
;; check if the symbol under point is a function or variable
|
||
(let ((sym
|
||
(intern
|
||
(save-excursion
|
||
(goto-char pos) (skip-syntax-backward "w_")
|
||
(buffer-substring (point)
|
||
(progn (skip-syntax-forward "w_")
|
||
(point)))))))
|
||
(when (or (boundp sym) (fboundp sym) (facep sym))
|
||
(describe-symbol sym)))))
|
||
|
||
;; When you change this, you may also need to change the number of
|
||
;; frames that the debugger skips.
|
||
(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."
|
||
(if (or inhibit-debug-on-entry debugger-jumping-flag)
|
||
nil
|
||
(let ((inhibit-debug-on-entry t))
|
||
(funcall debugger 'debug))))
|
||
|
||
;;;###autoload
|
||
(defun debug-on-entry (function)
|
||
"Request FUNCTION to invoke debugger each time it is called.
|
||
|
||
When called interactively, prompt for FUNCTION in the minibuffer.
|
||
|
||
This works by modifying the definition of FUNCTION. If you tell the
|
||
debugger to continue, FUNCTION's execution proceeds. If FUNCTION is a
|
||
normal function or a macro written in Lisp, you can also step through
|
||
its execution. FUNCTION can also be a primitive that is not a special
|
||
form, in which case stepping is not possible. Break-on-entry for
|
||
primitive functions only works when that function is called from Lisp.
|
||
|
||
Use \\[cancel-debug-on-entry] to cancel the effect of this command.
|
||
Redefining FUNCTION also cancels it."
|
||
(interactive
|
||
(let ((fn (function-called-at-point)) val)
|
||
(when (special-form-p fn)
|
||
(setq fn nil))
|
||
(setq val (completing-read
|
||
(if fn
|
||
(format "Debug on entry to function (default %s): " fn)
|
||
"Debug on entry to function: ")
|
||
obarray
|
||
#'(lambda (symbol)
|
||
(and (fboundp symbol)
|
||
(not (special-form-p symbol))))
|
||
t nil nil (symbol-name fn)))
|
||
(list (if (equal val "") fn (intern val)))))
|
||
(advice-add function :before #'debug--implement-debug-on-entry
|
||
'((depth . -100)))
|
||
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.
|
||
If FUNCTION is nil, cancel debug-on-entry for all functions.
|
||
When called interactively, prompt for FUNCTION in the minibuffer.
|
||
To specify a nil argument interactively, exit with an empty minibuffer."
|
||
(interactive
|
||
(list (let ((name
|
||
(completing-read
|
||
"Cancel debug on entry to function (default all functions): "
|
||
(mapcar #'symbol-name (debug--function-list)) nil t)))
|
||
(when name
|
||
(unless (string= name "")
|
||
(intern name))))))
|
||
(if function
|
||
(progn
|
||
(advice-remove function #'debug--implement-debug-on-entry)
|
||
function)
|
||
(message "Canceling debug-on-entry for all functions")
|
||
(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."
|
||
(interactive)
|
||
(require 'help-mode)
|
||
(help-setup-xref '(debugger-list-functions)
|
||
(called-interactively-p 'interactive))
|
||
(with-output-to-temp-buffer (help-buffer)
|
||
(with-current-buffer standard-output
|
||
(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)
|
||
|
||
;;; debug.el ends here
|