| 1 | ;;; find-gc.el --- detect functions that call the garbage collector |
| 2 | |
| 3 | ;; Copyright (C) 1992, 2001-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;; Maintainer: emacs-devel@gnu.org |
| 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 3 of the License, or |
| 12 | ;; (at your option) 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. If not, see <http://www.gnu.org/licenses/>. |
| 21 | |
| 22 | ;;; Commentary: |
| 23 | |
| 24 | ;; Produce in find-gc-unsafe-list the set of all functions that may invoke GC. |
| 25 | ;; This expects the Emacs sources to live in find-gc-source-directory. |
| 26 | |
| 27 | ;;; Code: |
| 28 | |
| 29 | (defvar find-gc-unsafe-list nil |
| 30 | "The list of unsafe functions is placed here by `find-gc-unsafe'.") |
| 31 | |
| 32 | (defvar find-gc-source-directory |
| 33 | (file-name-as-directory (expand-file-name "src" source-directory)) |
| 34 | "Directory containing Emacs C sources.") |
| 35 | |
| 36 | (defvar find-gc-subrs-callers nil |
| 37 | "Alist of users of subrs, from GC testing. |
| 38 | Each entry has the form (FUNCTION . FUNCTIONS-THAT-CALL-IT).") |
| 39 | |
| 40 | (defvar find-gc-subrs-called nil |
| 41 | "Alist of subrs called, in GC testing. |
| 42 | Each entry has the form (FUNCTION . FUNCTIONS-IT-CALLS).") |
| 43 | |
| 44 | |
| 45 | ;;; Functions on this list are safe, even if they appear to be able |
| 46 | ;;; to call the target. |
| 47 | |
| 48 | (defvar find-gc-noreturn-list '(Fsignal Fthrow wrong_type_argument)) |
| 49 | |
| 50 | ;;; This was originally generated directory-files, but there were |
| 51 | ;;; too many files there that were not actually compiled. The |
| 52 | ;;; list below was created for a HP-UX 7.0 system. |
| 53 | |
| 54 | (defvar find-gc-source-files |
| 55 | '("dispnew.c" "scroll.c" "xdisp.c" "window.c" |
| 56 | "term.c" "cm.c" "emacs.c" "keyboard.c" "macros.c" |
| 57 | "keymap.c" "sysdep.c" "buffer.c" "filelock.c" |
| 58 | "insdel.c" "marker.c" "minibuf.c" "fileio.c" |
| 59 | "dired.c" "cmds.c" "casefiddle.c" |
| 60 | "indent.c" "search.c" "regex.c" "undo.c" |
| 61 | "alloc.c" "data.c" "doc.c" "editfns.c" |
| 62 | "callint.c" "eval.c" "fns.c" "print.c" "lread.c" |
| 63 | "syntax.c" "unexcoff.c" |
| 64 | "bytecode.c" "process.c" "callproc.c" "doprnt.c" |
| 65 | "xterm.c" "xfns.c")) |
| 66 | |
| 67 | |
| 68 | (defun find-gc-unsafe () |
| 69 | "Return a list of unsafe functions--that is, which can call GC. |
| 70 | Also store it in `find-gc-unsafe-list'." |
| 71 | (trace-call-tree nil) |
| 72 | (trace-use-tree) |
| 73 | (find-unsafe-funcs 'Fgarbage_collect) |
| 74 | (setq find-gc-unsafe-list |
| 75 | (sort find-gc-unsafe-list |
| 76 | (function (lambda (x y) |
| 77 | (string-lessp (car x) (car y))))))) |
| 78 | |
| 79 | ;;; This does a depth-first search to find all functions that can |
| 80 | ;;; ultimately call the function "target". The result is an a-list |
| 81 | ;;; in find-gc-unsafe-list; the cars are the unsafe functions, and the cdrs |
| 82 | ;;; are (one of) the unsafe functions that these functions directly |
| 83 | ;;; call. |
| 84 | |
| 85 | (defun find-unsafe-funcs (target) |
| 86 | (setq find-gc-unsafe-list (list (list target))) |
| 87 | (trace-unsafe target)) |
| 88 | |
| 89 | (defun trace-unsafe (func) |
| 90 | (let ((used (assq func find-gc-subrs-callers))) |
| 91 | (or used |
| 92 | (error "No find-gc-subrs-callers for %s" (car find-gc-unsafe-list))) |
| 93 | (while (setq used (cdr used)) |
| 94 | (or (assq (car used) find-gc-unsafe-list) |
| 95 | (memq (car used) find-gc-noreturn-list) |
| 96 | (progn |
| 97 | (push (cons (car used) func) find-gc-unsafe-list) |
| 98 | (trace-unsafe (car used))))))) |
| 99 | |
| 100 | |
| 101 | |
| 102 | |
| 103 | (defun trace-call-tree (&optional ignored) |
| 104 | (message "Setting up directories...") |
| 105 | (setq find-gc-subrs-called nil) |
| 106 | (let ((case-fold-search nil) |
| 107 | (default-directory find-gc-source-directory) |
| 108 | (files find-gc-source-files) |
| 109 | name entry rtlfile) |
| 110 | (dolist (file files) |
| 111 | (message "Compiling %s..." file) |
| 112 | (call-process "gcc" nil nil nil "-I" "." "-I" "../lib" |
| 113 | "-fdump-rtl-expand" "-o" null-device "-c" file) |
| 114 | (setq rtlfile |
| 115 | (file-expand-wildcards (format "%s.*.expand" file) t)) |
| 116 | (if (/= 1 (length rtlfile)) |
| 117 | (message "Error compiling `%s'?" file) |
| 118 | (with-temp-buffer |
| 119 | (insert-file-contents (setq rtlfile (car rtlfile))) |
| 120 | (delete-file rtlfile) |
| 121 | (while (re-search-forward ";; Function \\|(call_insn " nil t) |
| 122 | (if (= (char-after (- (point) 3)) ?o) |
| 123 | (progn |
| 124 | (looking-at "[a-zA-Z0-9_]+") |
| 125 | (setq name (intern (match-string 0))) |
| 126 | (message "%s : %s" (car files) name) |
| 127 | (setq entry (list name) |
| 128 | find-gc-subrs-called |
| 129 | (cons entry find-gc-subrs-called))) |
| 130 | (if (looking-at ".*\n?.*\"\\([A-Za-z0-9_]+\\)\"") |
| 131 | (progn |
| 132 | (setq name (intern (match-string 1))) |
| 133 | (or (memq name (cdr entry)) |
| 134 | (setcdr entry (cons name (cdr entry))))))))))))) |
| 135 | |
| 136 | (defun trace-use-tree () |
| 137 | (setq find-gc-subrs-callers (mapcar 'list (mapcar 'car find-gc-subrs-called))) |
| 138 | (let ((ptr find-gc-subrs-called) |
| 139 | p2 found) |
| 140 | (while ptr |
| 141 | (setq p2 (car ptr)) |
| 142 | (while (setq p2 (cdr p2)) |
| 143 | (if (setq found (assq (car p2) find-gc-subrs-callers)) |
| 144 | (setcdr found (cons (car (car ptr)) (cdr found))))) |
| 145 | (setq ptr (cdr ptr))))) |
| 146 | |
| 147 | (provide 'find-gc) |
| 148 | |
| 149 | ;;; find-gc.el ends here |