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Diffstat (limited to 'admin/find-gc.el')
| -rw-r--r-- | admin/find-gc.el | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/admin/find-gc.el b/admin/find-gc.el new file mode 100644 index 00000000000..83eb26e86d7 --- /dev/null +++ b/admin/find-gc.el @@ -0,0 +1,149 @@ +;;; find-gc.el --- detect functions that call the garbage collector + +;; Copyright (C) 1992, 2001-2014 Free Software Foundation, Inc. + +;; Maintainer: emacs-devel@gnu.org + +;; This file is part of GNU Emacs. + +;; GNU Emacs is free software: you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; GNU Emacs is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. + +;;; Commentary: + +;; Produce in find-gc-unsafe-list the set of all functions that may invoke GC. +;; This expects the Emacs sources to live in find-gc-source-directory. + +;;; Code: + +(defvar find-gc-unsafe-list nil + "The list of unsafe functions is placed here by `find-gc-unsafe'.") + +(defvar find-gc-source-directory + (file-name-as-directory (expand-file-name "src" source-directory)) + "Directory containing Emacs C sources.") + +(defvar find-gc-subrs-callers nil + "Alist of users of subrs, from GC testing. +Each entry has the form (FUNCTION . FUNCTIONS-THAT-CALL-IT).") + +(defvar find-gc-subrs-called nil + "Alist of subrs called, in GC testing. +Each entry has the form (FUNCTION . FUNCTIONS-IT-CALLS).") + + +;;; Functions on this list are safe, even if they appear to be able +;;; to call the target. + +(defvar find-gc-noreturn-list '(Fsignal Fthrow wrong_type_argument)) + +;;; This was originally generated directory-files, but there were +;;; too many files there that were not actually compiled. The +;;; list below was created for a HP-UX 7.0 system. + +(defvar find-gc-source-files + '("dispnew.c" "scroll.c" "xdisp.c" "window.c" + "term.c" "cm.c" "emacs.c" "keyboard.c" "macros.c" + "keymap.c" "sysdep.c" "buffer.c" "filelock.c" + "insdel.c" "marker.c" "minibuf.c" "fileio.c" + "dired.c" "cmds.c" "casefiddle.c" + "indent.c" "search.c" "regex.c" "undo.c" + "alloc.c" "data.c" "doc.c" "editfns.c" + "callint.c" "eval.c" "fns.c" "print.c" "lread.c" + "syntax.c" "unexcoff.c" + "bytecode.c" "process.c" "callproc.c" "doprnt.c" + "xterm.c" "xfns.c")) + + +(defun find-gc-unsafe () + "Return a list of unsafe functions--that is, which can call GC. +Also store it in `find-gc-unsafe-list'." + (trace-call-tree nil) + (trace-use-tree) + (find-unsafe-funcs 'Fgarbage_collect) + (setq find-gc-unsafe-list + (sort find-gc-unsafe-list + (function (lambda (x y) + (string-lessp (car x) (car y))))))) + +;;; This does a depth-first search to find all functions that can +;;; ultimately call the function "target". The result is an a-list +;;; in find-gc-unsafe-list; the cars are the unsafe functions, and the cdrs +;;; are (one of) the unsafe functions that these functions directly +;;; call. + +(defun find-unsafe-funcs (target) + (setq find-gc-unsafe-list (list (list target))) + (trace-unsafe target)) + +(defun trace-unsafe (func) + (let ((used (assq func find-gc-subrs-callers))) + (or used + (error "No find-gc-subrs-callers for %s" (car find-gc-unsafe-list))) + (while (setq used (cdr used)) + (or (assq (car used) find-gc-unsafe-list) + (memq (car used) find-gc-noreturn-list) + (progn + (push (cons (car used) func) find-gc-unsafe-list) + (trace-unsafe (car used))))))) + + + + +(defun trace-call-tree (&optional ignored) + (message "Setting up directories...") + (setq find-gc-subrs-called nil) + (let ((case-fold-search nil) + (default-directory find-gc-source-directory) + (files find-gc-source-files) + name entry rtlfile) + (dolist (file files) + (message "Compiling %s..." file) + (call-process "gcc" nil nil nil "-I" "." "-I" "../lib" + "-fdump-rtl-expand" "-o" null-device "-c" file) + (setq rtlfile + (file-expand-wildcards (format "%s.*.expand" file) t)) + (if (/= 1 (length rtlfile)) + (message "Error compiling `%s'?" file) + (with-temp-buffer + (insert-file-contents (setq rtlfile (car rtlfile))) + (delete-file rtlfile) + (while (re-search-forward ";; Function \\|(call_insn " nil t) + (if (= (char-after (- (point) 3)) ?o) + (progn + (looking-at "[a-zA-Z0-9_]+") + (setq name (intern (match-string 0))) + (message "%s : %s" (car files) name) + (setq entry (list name) + find-gc-subrs-called + (cons entry find-gc-subrs-called))) + (if (looking-at ".*\n?.*\"\\([A-Za-z0-9_]+\\)\"") + (progn + (setq name (intern (match-string 1))) + (or (memq name (cdr entry)) + (setcdr entry (cons name (cdr entry))))))))))))) + +(defun trace-use-tree () + (setq find-gc-subrs-callers (mapcar 'list (mapcar 'car find-gc-subrs-called))) + (let ((ptr find-gc-subrs-called) + p2 found) + (while ptr + (setq p2 (car ptr)) + (while (setq p2 (cdr p2)) + (if (setq found (assq (car p2) find-gc-subrs-callers)) + (setcdr found (cons (car (car ptr)) (cdr found))))) + (setq ptr (cdr ptr))))) + +(provide 'find-gc) + +;;; find-gc.el ends here |