gecko/toolkit/modules/Deprecated.jsm

82 lines
2.4 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
this.EXPORTED_SYMBOLS = [ "Deprecated" ];
const Cu = Components.utils;
const Ci = Components.interfaces;
const PREF_DEPRECATION_WARNINGS = "devtools.errorconsole.deprecation_warnings";
Cu.import("resource://gre/modules/Services.jsm");
// A flag that indicates whether deprecation warnings should be logged.
var logWarnings = Services.prefs.getBoolPref(PREF_DEPRECATION_WARNINGS);
Services.prefs.addObserver(PREF_DEPRECATION_WARNINGS,
function (aSubject, aTopic, aData) {
logWarnings = Services.prefs.getBoolPref(PREF_DEPRECATION_WARNINGS);
}, false);
/**
* Build a callstack log message.
*
* @param nsIStackFrame aStack
* A callstack to be converted into a string log message.
*/
function stringifyCallstack (aStack) {
// If aStack is invalid, use Components.stack (ignoring the last frame).
if (!aStack || !(aStack instanceof Ci.nsIStackFrame)) {
aStack = Components.stack.caller;
}
let frame = aStack.caller;
let msg = "";
// Get every frame in the callstack.
while (frame) {
msg += frame.filename + " " + frame.lineNumber +
" " + frame.name + "\n";
frame = frame.caller;
}
return msg;
}
this.Deprecated = {
/**
* Log a deprecation warning.
*
* @param string aText
* Deprecation warning text.
* @param string aUrl
* A URL pointing to documentation describing deprecation
* and the way to address it.
* @param nsIStackFrame aStack
* An optional callstack. If it is not provided a
* snapshot of the current JavaScript callstack will be
* logged.
*/
warning: function (aText, aUrl, aStack) {
if (!logWarnings) {
return;
}
// If URL is not provided, report an error.
if (!aUrl) {
Cu.reportError("Error in Deprecated.warning: warnings must " +
"provide a URL documenting this deprecation.");
return;
}
let textMessage = "DEPRECATION WARNING: " + aText +
"\nYou may find more details about this deprecation at: " +
aUrl + "\n" +
// Append a callstack part to the deprecation message.
stringifyCallstack(aStack);
// Report deprecation warning.
Cu.reportError(textMessage);
}
};