toolkit/content/debug.js

   1 # vim:set ts=2 sw=2 sts=2 ci et:
   2 # -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   3 #
   4 # ***** BEGIN LICENSE BLOCK *****
   5 # Version: MPL 1.1/GPL 2.0/LGPL 2.1
   6 #
   7 # The contents of this file are subject to the Mozilla Public License Version
   8 # 1.1 (the "License"); you may not use this file except in compliance with
   9 # the License. You may obtain a copy of the License at
  10 # http://www.mozilla.org/MPL/
  11 #
  12 # Software distributed under the License is distributed on an "AS IS" basis,
  13 # WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  14 # for the specific language governing rights and limitations under the
  15 # License.
  16 #
  17 # The Original Code is the Places Bookmark Properties.
  18 #
  19 # The Initial Developer of the Original Code is
  20 # Google Inc.
  21 # Portions created by the Initial Developer are Copyright (C) 2006
  22 # the Initial Developer. All Rights Reserved.
  23 #
  24 # Contributor(s):
  25 #   Joe Hughes <jhughes@google.com>
  26 #   Ben Goodger <beng@google.com>
  27 #
  28 # Alternatively, the contents of this file may be used under the terms of
  29 # either the GNU General Public License Version 2 or later (the "GPL"), or
  30 # the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  31 # in which case the provisions of the GPL or the LGPL are applicable instead
  32 # of those above. If you wish to allow use of your version of this file only
  33 # under the terms of either the GPL or the LGPL, and not to allow others to
  34 # use your version of this file under the terms of the MPL, indicate your
  35 # decision by deleting the provisions above and replace them with the notice
  36 # and other provisions required by the GPL or the LGPL. If you do not delete
  37 # the provisions above, a recipient may use your version of this file under
  38 # the terms of any one of the MPL, the GPL or the LGPL.
  39 #
  40 # ***** END LICENSE BLOCK *****
  41 #
  42 # This file contains functions that are useful for debugging purposes from
  43 # within JavaScript code.
  44
  45 var EXPORTED_SYMBOLS = ["NS_ASSERT"];
  46
  47 var gTraceOnAssert = true;
  48
  49 /**
  50  * This function provides a simple assertion function for JavaScript.
  51  * If the condition is true, this function will do nothing.  If the
  52  * condition is false, then the message will be printed to the console
  53  * and an alert will appear showing a stack trace, so that the (alpha
  54  * or nightly) user can file a bug containing it.  For future enhancements,
  55  * see bugs 330077 and 330078.
  56  *
  57  * To suppress the dialogs, you can run with the environment variable
  58  * XUL_ASSERT_PROMPT set to 0 (if unset, this defaults to 1).
  59  *
  60  * @param condition represents the condition that we're asserting to be
  61  *                  true when we call this function--should be
  62  *                  something that can be evaluated as a boolean.
  63  * @param message   a string to be displayed upon failure of the assertion
  64  */
  65
  66 function NS_ASSERT(condition, message) {
  67   if (condition)
  68     return;
  69
  70   var releaseBuild = true;
  71   var defB = Components.classes["@mozilla.org/preferences-service;1"]
  72                        .getService(Components.interfaces.nsIPrefService)
  73                        .getDefaultBranch(null);
  74   try {
  75     switch (defB.getCharPref("app.update.channel")) {
  76       case "nightly":
  77       case "beta":
  78       case "default":
  79         releaseBuild = false;
  80     }
  81   } catch(ex) {}
  82
  83   var caller = arguments.callee.caller;
  84   var assertionText = "ASSERT: " + message + "\n";
  85
  86   if (releaseBuild) {
  87     // Just report the error to the console
  88     Components.utils.reportError(assertionText);
  89     return;
  90   }
  91
  92   // Otherwise, dump to stdout and launch an assertion failure dialog
  93   dump(assertionText);
  94
  95   var stackText = "";
  96   if (gTraceOnAssert) {
  97     stackText = "Stack Trace: \n";
  98     var count = 0;
  99     while (caller) {
 100       stackText += count++ + ":" + caller.name + "(";
 101       for (var i = 0; i < caller.arguments.length; ++i) {
 102         var arg = caller.arguments[i];
 103         stackText += arg;
 104         if (i < caller.arguments.length - 1)
 105           stackText += ",";
 106       }
 107       stackText += ")\n";
 108       caller = caller.arguments.callee.caller;
 109     }
 110   }
 111
 112   var environment = Components.classes["@mozilla.org/process/environment;1"].
 113                     getService(Components.interfaces.nsIEnvironment);
 114   if (environment.exists("XUL_ASSERT_PROMPT") &&
 115       !parseInt(environment.get("XUL_ASSERT_PROMPT")))
 116     return;
 117
 118   var source = null;
 119   if (this.window)
 120     source = this.window;
 121   var ps = Components.classes["@mozilla.org/embedcomp/prompt-service;1"].
 122            getService(Components.interfaces.nsIPromptService);
 123   ps.alert(source, "Assertion Failed", assertionText + stackText);
 124 }