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authorGlenn Morris <rgm@gnu.org>2014-05-10 18:53:42 -0700
committerGlenn Morris <rgm@gnu.org>2014-05-10 18:53:42 -0700
commite7caef591fa1a4348f40a9da72f2718371bbfefb (patch)
treec68d8aa0ac21f18fa8c03a945f9c7bd9780fbb31 /admin/find-gc.el
parent6d80e8a9eb366714415cc62fcbea88d37526236b (diff)
downloademacs-e7caef591fa1a4348f40a9da72f2718371bbfefb.tar.gz
Move lisp/emacs-lisp/find-gc.el to admin/
Ref: http://lists.gnu.org/archive/html/emacs-devel/2014-05/msg00118.html
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+;;; 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