binutils/dwarf-mode.el

   1 ;;; dwarf-mode.el --- Browser for DWARF information.
   2
   3 ;; Version: 1.0
   4
   5 ;; This file is not part of GNU Emacs, but is distributed under the
   6 ;; same terms:
   7
   8 ;; GNU Emacs is free software: you can redistribute it and/or modify
   9 ;; it under the terms of the GNU General Public License as published by
  10 ;; the Free Software Foundation, either version 3 of the License, or
  11 ;; (at your option) any later version.
  12
  13 ;; GNU Emacs is distributed in the hope that it will be useful,
  14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;; GNU General Public License for more details.
  17
  18 ;; You should have received a copy of the GNU General Public License
  19 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 ;;; Code:
  22
  23 (defvar dwarf-objdump-program "objdump")
  24
  25 (defconst dwarf-font-lock-keywords
  26   '(
  27     ;; Name and linkage name.
  28     ("DW_AT_[a-z_]*name\\s *: .*:\\(.*\\)\\s *$"
  29      (1 font-lock-function-name-face))
  30
  31     ("Compilation Unit @ offset 0x[0-9a-f]+"
  32      (0 font-lock-string-face))
  33     ))
  34
  35 (defvar dwarf-file nil
  36   "Buffer-local variable holding the file name passed to objdump.")
  37
  38 ;; Expand a "..." to show all the child DIES.  NEW-DEPTH controls how
  39 ;; deep to display the new dies; `nil' means display all of them.
  40 (defun dwarf-do-insert-substructure (new-depth die)
  41   (let ((inhibit-read-only t))
  42     (beginning-of-line)
  43     (delete-region (point) (progn
  44                              (end-of-line)
  45                              (forward-char)
  46                              (point)))
  47     (save-excursion
  48       (apply #'call-process dwarf-objdump-program nil (current-buffer) nil
  49              "-Wi" (concat "--dwarf-start=0x" die)
  50              (expand-file-name dwarf-file)
  51              (if new-depth (list (concat "--dwarf-depth="
  52                                          (int-to-string new-depth))))))
  53     (set-buffer-modified-p nil)))
  54
  55 (defun dwarf-insert-substructure-button (die)
  56   (beginning-of-line)
  57   (unless (looking-at "^ <\\([0-9]+\\)>")
  58     (error "Unrecognized line."))
  59   (let ((new-depth (1+ (string-to-int (match-string 1)))))
  60     (dwarf-do-insert-substructure new-depth die)))
  61
  62 (defun dwarf-insert-substructure (arg)
  63   "Expand a `...' to show children of the current DIE.
  64 By default, expands just one level of children.
  65 A prefix argument means expand all children."
  66   (interactive "P")
  67   (beginning-of-line)
  68   (unless (looking-at "^ <\\([0-9]+\\)><\\([0-9a-f]+\\)>")
  69     (error "Unrecognized line."))
  70   (let ((die (match-string 2)))
  71     (if arg
  72         (dwarf-do-insert-substructure nil die)
  73       (dwarf-insert-substructure-button die))))
  74
  75 ;; Called when a button is pressed.
  76 ;; Either follows a DIE reference, or expands a "...".
  77 (defun dwarf-die-button-action (button)
  78   (let* ((die (button-get button 'die))
  79          ;; Note that the first number can only be decimal.
  80          (die-rx (concat "^\\s *\\(<[0-9]+>\\)?<"
  81                          die ">[^<]"))
  82          (old (point))
  83          (is-ref (button-get button 'die-ref)))
  84     (if is-ref
  85         (progn
  86           (goto-char (point-min))
  87           (if (re-search-forward die-rx nil 'move)
  88               (push-mark old)
  89             (goto-char old)
  90             (error "Could not find DIE <0x%s>" die)))
  91       (dwarf-insert-substructure-button die))))
  92
  93 ;; Button definition.
  94 (define-button-type 'dwarf-die-button
  95   'follow-link t
  96   'action #'dwarf-die-button-action)
  97
  98 ;; Helper regexp to match a DIE reference.
  99 (defconst dwarf-die-reference ": \\(<0x\\([0-9a-f]+\\)>\\)\\s *$")
 100
 101 ;; Helper regexp to match a `...' indicating that there are hidden
 102 ;; children.
 103 (defconst dwarf-die-more "^ <[0-9]+><\\([0-9a-z]+\\)>: \\([.][.][.]\\)")
 104
 105 ;; jit-lock callback function to fontify a region.  This applies the
 106 ;; buttons, since AFAICT there is no good way to apply buttons via
 107 ;; font-lock.
 108 (defun dwarf-fontify-region (start end)
 109   (save-excursion
 110     (let ((beg-line (progn (goto-char start) (line-beginning-position)))
 111           (end-line (progn (goto-char end) (line-end-position))))
 112       (goto-char beg-line)
 113       (while (re-search-forward dwarf-die-reference end-line 'move)
 114         (let ((b-start (match-beginning 1))
 115               (b-end (match-end 1))
 116               (hex (match-string-no-properties 2)))
 117           (make-text-button b-start b-end :type 'dwarf-die-button
 118                             'die hex 'die-ref t)))
 119       ;; This is a bogus approach.  Why can't we make buttons from the
 120       ;; font-lock defaults?
 121       (goto-char beg-line)
 122       (while (re-search-forward dwarf-die-more end-line 'move)
 123         (let ((hex (match-string-no-properties 1))
 124               (b-start (match-beginning 2))
 125               (b-end (match-end 2)))
 126           (make-text-button b-start b-end :type 'dwarf-die-button
 127                             'die hex 'die-ref nil))))))
 128
 129 ;; Run objdump and insert the contents into the buffer.  The arguments
 130 ;; are the way they are because this is also called as a
 131 ;; revert-buffer-function.
 132 (defun dwarf-do-refresh (&rest ignore)
 133   (let ((inhibit-read-only t))
 134     (erase-buffer)
 135     (save-excursion
 136       (call-process dwarf-objdump-program
 137                     nil (current-buffer) nil
 138                     "-Wi" "--dwarf-depth=1"
 139                     (expand-file-name dwarf-file)))
 140     (set-buffer-modified-p nil)))
 141
 142 ;;;###autoload
 143 (define-derived-mode dwarf-mode special-mode "DWARF"
 144   "Major mode for browsing DWARF output.
 145
 146 \\{dwarf-mode-map}"
 147
 148   (set (make-local-variable 'font-lock-defaults) '(dwarf-font-lock-keywords))
 149   ;; FIXME: we could be smarter and check the file time.
 150   (set (make-local-variable 'revert-buffer-function) #'dwarf-do-refresh)
 151   (jit-lock-register #'dwarf-fontify-region))
 152
 153 (define-key dwarf-mode-map [(control ?m)] #'dwarf-insert-substructure)
 154
 155 ;;:###autoload
 156 (defun dwarf-browse (file)
 157   "Invoke `objdump' and put output into a `dwarf-mode' buffer.
 158 This is the main interface to `dwarf-mode'."
 159   (interactive "fFile name: ")
 160   (let* ((base-name (file-name-nondirectory file))
 161          (buffer (generate-new-buffer (concat "*DWARF for " base-name "*"))))
 162     (pop-to-buffer buffer)
 163     (dwarf-mode)
 164     (set (make-local-variable 'dwarf-file) file)
 165     (dwarf-do-refresh)))
 166
 167 (provide 'dwarf-mode)