Initial revision

1 files changed, 127 insertions, 0 deletions

diff --git a/lisp/find-gc.el b/lisp/find-gc.el
new file mode 100644
index 00000000000..3504d2949d8
--- /dev/null
+++ b/lisp/find-gc.el
@@ -0,0 +1,127 @@
+;;;; find-gc.el
+
+
+;;; Produce in unsafe-list the set of all functions that may invoke GC.
+;;; This expects the Emacs sources to live in emacs-source-directory.
+;;; It creates a temporary working directory /tmp/esrc.
+
+(defun find-gc-unsafe ()
+  (trace-call-tree nil)
+  (trace-use-tree)
+  (find-unsafe-funcs 'Fgarbage_collect)
+  (setq unsafe-list (sort unsafe-list
+                          (function (lambda (x y)
+                                      (string-lessp (car x) (car y))))))
+)
+
+(setq emacs-source-directory "/usr/gnu/src/dist/src")
+
+
+;;; This does a depth-first search to find all functions that can
+;;; ultimately call the function "target".  The result is an a-list
+;;; in 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 unsafe-list (list (list target)))
+  (trace-unsafe target)
+)
+
+(defun trace-unsafe (func)
+  (let ((used (assq func subrs-used)))
+    (or used
+        (error "No subrs-used for %s" (car unsafe-list)))
+    (while (setq used (cdr used))
+      (or (assq (car used) unsafe-list)
+          (memq (car used) noreturn-list)
+          (progn
+            (setq unsafe-list (cons (cons (car used) func) unsafe-list))
+            (trace-unsafe (car used))))))
+)
+
+
+;;; Functions on this list are safe, even if they appear to be able
+;;; to call the target.
+
+(setq noreturn-list '( Fsignal Fthrow wrong_type_argument ))
+
+
+;;; This produces an a-list of functions in subrs-called.  The cdr of
+;;; each entry is a list of functions which the function in car calls.
+
+(defun trace-call-tree (&optional already-setup)
+  (message "Setting up directories...")
+  (or already-setup
+      (progn
+        ;; Gee, wouldn't a built-in "system" function be handy here.
+        (call-process "csh" nil nil nil "-c" "rm -rf /tmp/esrc")
+        (call-process "csh" nil nil nil "-c" "mkdir /tmp/esrc")
+        (call-process "csh" nil nil nil "-c"
+                      (format "ln -s %s/*.[ch] /tmp/esrc"
+                              emacs-source-directory))))
+  (save-excursion
+    (set-buffer (get-buffer-create "*Trace Call Tree*"))
+    (setq subrs-called nil)
+    (let ((case-fold-search nil)
+          (files source-files)
+          name entry)
+      (while files
+        (message "Compiling %s..." (car files))
+        (call-process "csh" nil nil nil "-c"
+                      (format "gcc -dr -c /tmp/esrc/%s -o /dev/null"
+                              (car files)))
+        (erase-buffer)
+        (insert-file-contents (concat "/tmp/esrc/" (car files) ".rtl"))
+        (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 (buffer-substring (match-beginning 0)
+                                                     (match-end 0))))
+                (message "%s : %s" (car files) name)
+                (setq entry (list name)
+                      subrs-called (cons entry subrs-called)))
+            (if (looking-at ".*\n?.*\"\\([A-Za-z0-9_]+\\)\"")
+                (progn
+                  (setq name (intern (buffer-substring (match-beginning 1)
+                                                       (match-end 1))))
+                  (or (memq name (cdr entry))
+                      (setcdr entry (cons name (cdr entry))))))))
+        (delete-file (concat "/tmp/esrc/" (car files) ".rtl"))
+        (setq files (cdr files)))))
+)
+
+
+;;; 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.
+
+(setq 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" "filemode.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"
+                     "abbrev.c" "syntax.c" "unexec.c" "mocklisp.c"
+                     "bytecode.c" "process.c" "callproc.c" "doprnt.c"
+                     "x11term.c" "x11fns.c"))
+
+
+;;; This produces an inverted a-list in subrs-used.  The cdr of each
+;;; entry is a list of functions that call the function in car.
+
+(defun trace-use-tree ()
+  (setq subrs-used (mapcar 'list (mapcar 'car subrs-called)))
+  (let ((ptr subrs-called)
+        p2 found)
+    (while ptr
+      (setq p2 (car ptr))
+      (while (setq p2 (cdr p2))
+        (if (setq found (assq (car p2) subrs-used))
+            (setcdr found (cons (car (car ptr)) (cdr found)))))
+      (setq ptr (cdr ptr))))
+)
+