code.delx.au - gnu-emacs/blob - lisp/emacs-lisp/find-gc.el

   1 ;;; find-gc.el --- detect functions that call the garbage collector
   2
   3 ;; Copyright (C) 1992, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22 ;; Boston, MA 02110-1301, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; Produce in find-gc-unsafe-list the set of all functions that may invoke GC.
  27 ;; This expects the Emacs sources to live in find-gc-source-directory.
  28 ;; It creates a temporary working directory /tmp/esrc.
  29
  30 ;;; Code:
  31
  32 (defvar find-gc-unsafe-list nil
  33   "The list of unsafe functions is placed here by `find-gc-unsafe'.")
  34
  35 (defvar find-gc-source-directory)
  36
  37 (defvar find-gc-subrs-callers nil
  38   "Alist of users of subrs, from GC testing.
  39 Each entry has the form (FUNCTION . FUNCTIONS-THAT-CALL-IT).")
  40
  41 (defvar find-gc-subrs-called nil
  42   "Alist of subrs called, in GC testing.
  43 Each entry has the form (FUNCTION . FUNCTIONS-IT-CALLS).")
  44
  45
  46 ;;; Functions on this list are safe, even if they appear to be able
  47 ;;; to call the target.
  48
  49 (defvar find-gc-noreturn-list '(Fsignal Fthrow wrong_type_argument))
  50
  51 ;;; This was originally generated directory-files, but there were
  52 ;;; too many files there that were not actually compiled.  The
  53 ;;; list below was created for a HP-UX 7.0 system.
  54
  55 (defvar find-gc-source-files
  56   '("dispnew.c" "scroll.c" "xdisp.c" "window.c"
  57     "term.c" "cm.c" "emacs.c" "keyboard.c" "macros.c"
  58     "keymap.c" "sysdep.c" "buffer.c" "filelock.c"
  59     "insdel.c" "marker.c" "minibuf.c" "fileio.c"
  60     "dired.c" "filemode.c" "cmds.c" "casefiddle.c"
  61     "indent.c" "search.c" "regex.c" "undo.c"
  62     "alloc.c" "data.c" "doc.c" "editfns.c"
  63     "callint.c" "eval.c" "fns.c" "print.c" "lread.c"
  64     "abbrev.c" "syntax.c" "unexec.c"
  65     "bytecode.c" "process.c" "callproc.c" "doprnt.c"
  66     "x11term.c" "x11fns.c"))
  67
  68
  69 (defun find-gc-unsafe ()
  70   "Return a list of unsafe functions--that is, which can call GC.
  71 Also store it in `find-gc-unsafe'."
  72   (trace-call-tree nil)
  73   (trace-use-tree)
  74   (find-unsafe-funcs 'Fgarbage_collect)
  75   (setq find-gc-unsafe-list
  76         (sort find-gc-unsafe-list
  77               (function (lambda (x y)
  78                           (string-lessp (car x) (car y))))))
  79 )
  80
  81 ;;; This does a depth-first search to find all functions that can
  82 ;;; ultimately call the function "target".  The result is an a-list
  83 ;;; in find-gc-unsafe-list; the cars are the unsafe functions, and the cdrs
  84 ;;; are (one of) the unsafe functions that these functions directly
  85 ;;; call.
  86
  87 (defun find-unsafe-funcs (target)
  88   (setq find-gc-unsafe-list (list (list target)))
  89   (trace-unsafe target)
  90 )
  91
  92 (defun trace-unsafe (func)
  93   (let ((used (assq func find-gc-subrs-callers)))
  94     (or used
  95         (error "No find-gc-subrs-callers for %s" (car find-gc-unsafe-list)))
  96     (while (setq used (cdr used))
  97       (or (assq (car used) find-gc-unsafe-list)
  98           (memq (car used) find-gc-noreturn-list)
  99           (progn
 100             (push (cons (car used) func) find-gc-unsafe-list)
 101             (trace-unsafe (car used))))))
 102 )
 103
 104
 105
 106
 107 (defun trace-call-tree (&optional already-setup)
 108   (message "Setting up directories...")
 109   (or already-setup
 110       (progn
 111         ;; Gee, wouldn't a built-in "system" function be handy here.
 112         (call-process "csh" nil nil nil "-c" "rm -rf /tmp/esrc")
 113         (call-process "csh" nil nil nil "-c" "mkdir /tmp/esrc")
 114         (call-process "csh" nil nil nil "-c"
 115                       (format "ln -s %s/*.[ch] /tmp/esrc"
 116                               find-gc-source-directory))))
 117   (save-excursion
 118     (set-buffer (get-buffer-create "*Trace Call Tree*"))
 119     (setq find-gc-subrs-called nil)
 120     (let ((case-fold-search nil)
 121           (files find-gc-source-files)
 122           name entry)
 123       (while files
 124         (message "Compiling %s..." (car files))
 125         (call-process "csh" nil nil nil "-c"
 126                       (format "gcc -dr -c /tmp/esrc/%s -o /dev/null"
 127                               (car files)))
 128         (erase-buffer)
 129         (insert-file-contents (concat "/tmp/esrc/" (car files) ".rtl"))
 130         (while (re-search-forward ";; Function \\|(call_insn " nil t)
 131           (if (= (char-after (- (point) 3)) ?o)
 132               (progn
 133                 (looking-at "[a-zA-Z0-9_]+")
 134                 (setq name (intern (buffer-substring (match-beginning 0)
 135                                                      (match-end 0))))
 136                 (message "%s : %s" (car files) name)
 137                 (setq entry (list name)
 138                       find-gc-subrs-called (cons entry find-gc-subrs-called)))
 139             (if (looking-at ".*\n?.*\"\\([A-Za-z0-9_]+\\)\"")
 140                 (progn
 141                   (setq name (intern (buffer-substring (match-beginning 1)
 142                                                        (match-end 1))))
 143                   (or (memq name (cdr entry))
 144                       (setcdr entry (cons name (cdr entry))))))))
 145         (delete-file (concat "/tmp/esrc/" (car files) ".rtl"))
 146         (setq files (cdr files)))))
 147 )
 148
 149
 150 (defun trace-use-tree ()
 151   (setq find-gc-subrs-callers (mapcar 'list (mapcar 'car find-gc-subrs-called)))
 152   (let ((ptr find-gc-subrs-called)
 153         p2 found)
 154     (while ptr
 155       (setq p2 (car ptr))
 156       (while (setq p2 (cdr p2))
 157         (if (setq found (assq (car p2) find-gc-subrs-callers))
 158             (setcdr found (cons (car (car ptr)) (cdr found)))))
 159       (setq ptr (cdr ptr))))
 160 )
 161
 162 (provide 'find-gc)
 163
 164 ;;; arch-tag: 4a26a538-a008-40d9-a1ef-23bb6dbecef4
 165 ;;; find-gc.el ends here