carbon2-commit: when `debug', abort when lisp error during loadup

[Ben Wing]

changeset:   4889:3465c3161fea
user:        Ben Wing <ben at xemacs.org>
date:        Wed Jan 13 01:55:56 2010 -0600
files:       lisp/ChangeLog lisp/loadup.el src/ChangeLog src/cmdloop.c src/lisp.h
description:
when `debug', abort when lisp error during loadup

loadup.el: When featurep `debug-xemacs' (configure --with-debug), set
	debug-on-error, so that we get an exit-to-debugger/assertion
	failure upon Lisp error during loadup.  Unset before dumping.

cmdloop.c: During really-early-error-handler, exit to the debugger and abort
	if an error occurs and
lisp.h: extern Vdebug_on_error.


diff -r 17b3dc5500b0 -r 3465c3161fea lisp/ChangeLog
--- a/lisp/ChangeLog	Tue Jan 12 23:19:13 2010 -0600
+++ b/lisp/ChangeLog	Wed Jan 13 01:55:56 2010 -0600
@@ -1,3 +1,12 @@
+2010-01-13  Ben Wing  <ben at xemacs.org>
+
+	* loadup.el:
+	* loadup.el (featurep):
+	* loadup.el (member):
+	When featurep `debug-xemacs' (configure --with-debug), set
+	debug-on-error, so that we get an exit-to-debugger/assertion
+	failure upon Lisp error during loadup.  Unset before dumping.
+
 2010-01-10  Ben Wing  <ben at xemacs.org>
 
 	* mule/mule-cmds.el (get-native-coding-system-from-language-environment):
diff -r 17b3dc5500b0 -r 3465c3161fea lisp/loadup.el
--- a/lisp/loadup.el	Tue Jan 12 23:19:13 2010 -0600
+++ b/lisp/loadup.el	Wed Jan 13 01:55:56 2010 -0600
@@ -2,7 +2,7 @@
 
 ;; Copyright (C) 1985, 1986, 1992, 1994, 1997 Free Software Foundation, Inc.
 ;; Copyright (C) 1996 Richard Mlynarik.
-;; Copyright (C) 1995, 1996, 2003 Ben Wing.
+;; Copyright (C) 1995, 1996, 2003, 2005 Ben Wing.
 
 ;; Maintainer: XEmacs Development Team
 ;; Keywords: internal, dumped
@@ -44,6 +44,12 @@
 ;; Help debug problems.
 (setq stack-trace-on-error t
       load-always-display-messages t)
+(when (featurep 'debug-xemacs)
+  ;; Immediately dump core upon an unhandled error, rather than just quitting
+  ;; the program.  This can also be achieved by setting an environment variable
+  ;; XEMACSDEBUG to contain '(setq debug-on-error t)', e.g.
+  ;; export XEMACSDEBUG='(setq debug-on-error t)'
+  (setq debug-on-error t))
 
 ;(princ (format "command-line-args: %s\n" command-line-args))
 ;(princ (format "configure-lisp-directory: %S\n" configure-lisp-directory))
@@ -239,7 +245,8 @@
     (really-free))
   ;; Make sure we don't dump with debugging messages turned on.
   (setq stack-trace-on-error nil
-	load-always-display-messages nil)
+	load-always-display-messages nil
+	debug-on-error nil)
   (dump-emacs
    (cond
     ((featurep 'infodock) "infodock")
diff -r 17b3dc5500b0 -r 3465c3161fea src/ChangeLog
--- a/src/ChangeLog	Tue Jan 12 23:19:13 2010 -0600
+++ b/src/ChangeLog	Wed Jan 13 01:55:56 2010 -0600
@@ -1,3 +1,10 @@
+2010-01-13  Ben Wing  <ben at xemacs.org>
+
+	* cmdloop.c:
+	During really-early-error-handler, exit to the debugger and abort
+	if an error occurs and 
+	* lisp.h: extern Vdebug_on_error.
+
 2010-01-12  Ben Wing  <ben at xemacs.org>
 
 	* sheap.c:
diff -r 17b3dc5500b0 -r 3465c3161fea src/cmdloop.c
--- a/src/cmdloop.c	Tue Jan 12 23:19:13 2010 -0600
+++ b/src/cmdloop.c	Wed Jan 13 01:55:56 2010 -0600
@@ -1,6 +1,6 @@
 /* Editor command loop.
    Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
-   Copyright (C) 1995, 1996, 2001, 2002, 2003 Ben Wing.
+   Copyright (C) 1995, 1996, 2001, 2002, 2003, 2005 Ben Wing.
 
 This file is part of XEmacs.
 
@@ -137,6 +137,30 @@
   stderr_out ("*** Backtrace\n");
   Fbacktrace (Qexternal_debugging_output, Qt);
   stderr_out ("*** Killing XEmacs\n");
+#ifdef DEBUG_XEMACS
+  /* When configured --with-debug, and debug-on-error is set, exit to the
+     debugger and abort.  This will happen during loadup/dumping.  There is
+     also code in signal_call_debugger() to do the same whenever running
+     noninteractively.  That's intended for use debugging e.g. batch byte
+     compilation, AFTER dumping has already happened, where the XEMACSDEBUG
+     variable can be set to '(setq debug-on-error t)' to trigger the
+     behavior.
+
+     Why do we need to duplicate the bomb-out check here?  Well,
+     signal_call_debugger() doesn't want to bomb out unless it has an
+     uncaught error, and in this case, we've installed a
+     call-with-condition-case handler, and so signal_call_debugger() can't
+     bomb out before calling us.  If we returned and let the error be
+     processed further, it *would* trigger the bomb-out-to-debugger
+     behavior, but in fact it never gets there because we do `kill-emacs'.
+     Therefore, we have to provide the bomb-to-debugger feature
+     ourselves. */
+  if (!NILP (Vdebug_on_error))
+    {
+      stderr_out ("XEmacs exiting to debugger.\n");
+      Fforce_debugging_signal (Qt);
+    }
+#endif
 #ifdef HAVE_MS_WINDOWS
   Fmswindows_message_box (build_msg_string ("Initialization error"),
 			  Qnil, Qnil);
diff -r 17b3dc5500b0 -r 3465c3161fea src/lisp.h
--- a/src/lisp.h	Tue Jan 12 23:19:13 2010 -0600
+++ b/src/lisp.h	Wed Jan 13 01:55:56 2010 -0600
@@ -4574,6 +4574,7 @@
 				...) PRINTF_ARGS (3, 4);
 extern int backtrace_with_internal_sections;
 
+extern Lisp_Object Vdebug_on_error;
 extern Lisp_Object Vstack_trace_on_error;
 
 /* Defined in event-stream.c */