lisp/find-gc.el

   1 ;;; find-gc.el --- detect functions that call the garbage collector
   2
   3 ;; Copyright (C) 1992 Free Software Foundation, Inc.
   4
   5 ;; This file is part of GNU Emacs.
   6
   7 ;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation; either version 1, or (at your option)
  10 ;; any later version.
  11
  12 ;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  19 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 ;;; Produce in unsafe-list the set of all functions that may invoke GC.
  22 ;;; This expects the Emacs sources to live in emacs-source-directory.
  23 ;;; It creates a temporary working directory /tmp/esrc.
  24
  25 (defun find-gc-unsafe ()
  26   (trace-call-tree nil)
  27   (trace-use-tree)
  28   (find-unsafe-funcs 'Fgarbage_collect)
  29   (setq unsafe-list (sort unsafe-list
  30                           (function (lambda (x y)
  31                                       (string-lessp (car x) (car y))))))
  32 )
  33
  34 (setq emacs-source-directory "/usr/gnu/src/dist/src")
  35
  36
  37 ;;; This does a depth-first search to find all functions that can
  38 ;;; ultimately call the function "target".  The result is an a-list
  39 ;;; in unsafe-list; the cars are the unsafe functions, and the cdrs
  40 ;;; are (one of) the unsafe functions that these functions directly
  41 ;;; call.
  42
  43 (defun find-unsafe-funcs (target)
  44   (setq unsafe-list (list (list target)))
  45   (trace-unsafe target)
  46 )
  47
  48 (defun trace-unsafe (func)
  49   (let ((used (assq func subrs-used)))
  50     (or used
  51         (error "No subrs-used for %s" (car unsafe-list)))
  52     (while (setq used (cdr used))
  53       (or (assq (car used) unsafe-list)
  54           (memq (car used) noreturn-list)
  55           (progn
  56             (setq unsafe-list (cons (cons (car used) func) unsafe-list))
  57             (trace-unsafe (car used))))))
  58 )
  59
  60
  61 ;;; Functions on this list are safe, even if they appear to be able
  62 ;;; to call the target.
  63
  64 (setq noreturn-list '( Fsignal Fthrow wrong_type_argument ))
  65
  66
  67 ;;; This produces an a-list of functions in subrs-called.  The cdr of
  68 ;;; each entry is a list of functions which the function in car calls.
  69
  70 (defun trace-call-tree (&optional already-setup)
  71   (message "Setting up directories...")
  72   (or already-setup
  73       (progn
  74         ;; Gee, wouldn't a built-in "system" function be handy here.
  75         (call-process "csh" nil nil nil "-c" "rm -rf /tmp/esrc")
  76         (call-process "csh" nil nil nil "-c" "mkdir /tmp/esrc")
  77         (call-process "csh" nil nil nil "-c"
  78                       (format "ln -s %s/*.[ch] /tmp/esrc"
  79                               emacs-source-directory))))
  80   (save-excursion
  81     (set-buffer (get-buffer-create "*Trace Call Tree*"))
  82     (setq subrs-called nil)
  83     (let ((case-fold-search nil)
  84           (files source-files)
  85           name entry)
  86       (while files
  87         (message "Compiling %s..." (car files))
  88         (call-process "csh" nil nil nil "-c"
  89                       (format "gcc -dr -c /tmp/esrc/%s -o /dev/null"
  90                               (car files)))
  91         (erase-buffer)
  92         (insert-file-contents (concat "/tmp/esrc/" (car files) ".rtl"))
  93         (while (re-search-forward ";; Function \\|(call_insn " nil t)
  94           (if (= (char-after (- (point) 3)) ?o)
  95               (progn
  96                 (looking-at "[a-zA-Z0-9_]+")
  97                 (setq name (intern (buffer-substring (match-beginning 0)
  98                                                      (match-end 0))))
  99                 (message "%s : %s" (car files) name)
 100                 (setq entry (list name)
 101                       subrs-called (cons entry subrs-called)))
 102             (if (looking-at ".*\n?.*\"\\([A-Za-z0-9_]+\\)\"")
 103                 (progn
 104                   (setq name (intern (buffer-substring (match-beginning 1)
 105                                                        (match-end 1))))
 106                   (or (memq name (cdr entry))
 107                       (setcdr entry (cons name (cdr entry))))))))
 108         (delete-file (concat "/tmp/esrc/" (car files) ".rtl"))
 109         (setq files (cdr files)))))
 110 )
 111
 112
 113 ;;; This was originally generated directory-files, but there were
 114 ;;; too many files there that were not actually compiled.  The
 115 ;;; list below was created for a HP-UX 7.0 system.
 116
 117 (setq source-files '("dispnew.c" "scroll.c" "xdisp.c" "window.c"
 118                      "term.c" "cm.c" "emacs.c" "keyboard.c" "macros.c"
 119                      "keymap.c" "sysdep.c" "buffer.c" "filelock.c"
 120                      "insdel.c" "marker.c" "minibuf.c" "fileio.c"
 121                      "dired.c" "filemode.c" "cmds.c" "casefiddle.c"
 122                      "indent.c" "search.c" "regex.c" "undo.c"
 123                      "alloc.c" "data.c" "doc.c" "editfns.c"
 124                      "callint.c" "eval.c" "fns.c" "print.c" "lread.c"
 125                      "abbrev.c" "syntax.c" "unexec.c" "mocklisp.c"
 126                      "bytecode.c" "process.c" "callproc.c" "doprnt.c"
 127                      "x11term.c" "x11fns.c"))
 128
 129
 130 ;;; This produces an inverted a-list in subrs-used.  The cdr of each
 131 ;;; entry is a list of functions that call the function in car.
 132
 133 (defun trace-use-tree ()
 134   (setq subrs-used (mapcar 'list (mapcar 'car subrs-called)))
 135   (let ((ptr subrs-called)
 136         p2 found)
 137     (while ptr
 138       (setq p2 (car ptr))
 139       (while (setq p2 (cdr p2))
 140         (if (setq found (assq (car p2) subrs-used))
 141             (setcdr found (cons (car (car ptr)) (cdr found)))))
 142       (setq ptr (cdr ptr))))
 143 )
 144
 145 ;;; find-gc.el ends here