1 files changed, 107 insertions, 0 deletions
diff --git a/toolkit/components/addoncompat/CompatWarning.jsm b/toolkit/components/addoncompat/CompatWarning.jsm
new file mode 100644
index 000000000..b32409a46
--- /dev/null
+++ b/toolkit/components/addoncompat/CompatWarning.jsm
@@ -0,0 +1,107 @@
+// 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/.
+
+this.EXPORTED_SYMBOLS = ["CompatWarning"];
+
+const Ci = Components.interfaces;
+const Cc = Components.classes;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Preferences.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "console",
+                                  "resource://gre/modules/Console.jsm");
+
+function section(number, url)
+{
+  const baseURL = "https://developer.mozilla.org/en-US/Firefox/Multiprocess_Firefox/Limitations_of_chrome_scripts";
+  return { number, url: baseURL + url };
+}
+
+var CompatWarning = {
+  // Sometimes we want to generate a warning, but put off issuing it
+  // until later. For example, if someone registers a listener, we
+  // might only want to warn about it if the listener actually
+  // fires. However, we want the warning to show a stack for the
+  // registration site.
+  delayedWarning: function(msg, addon, warning) {
+    function isShimLayer(filename) {
+      return filename.indexOf("CompatWarning.jsm") != -1 ||
+        filename.indexOf("RemoteAddonsParent.jsm") != -1 ||
+        filename.indexOf("RemoteAddonsChild.jsm") != -1 ||
+        filename.indexOf("multiprocessShims.js") != -1;
+    }
+
+    let stack = Components.stack;
+    while (stack && isShimLayer(stack.filename))
+      stack = stack.caller;
+
+    let alreadyWarned = false;
+
+    return function() {
+      if (alreadyWarned) {
+        return;
+      }
+      alreadyWarned = true;
+
+      if (addon) {
+        let histogram = Services.telemetry.getKeyedHistogramById("ADDON_SHIM_USAGE");
+        histogram.add(addon, warning ? warning.number : 0);
+      }
+
+      if (!Preferences.get("dom.ipc.shims.enabledWarnings", false))
+        return;
+
+      let error = Cc['@mozilla.org/scripterror;1'].createInstance(Ci.nsIScriptError);
+      if (!error || !Services.console) {
+        // Too late during shutdown to use the nsIConsole
+        return;
+      }
+
+      let message = `Warning: ${msg}`;
+      if (warning)
+        message += `\nMore info at: ${warning.url}`;
+
+      error.init(
+                 /* message*/ message,
+                 /* sourceName*/ stack ? stack.filename : "",
+                 /* sourceLine*/ stack ? stack.sourceLine : "",
+                 /* lineNumber*/ stack ? stack.lineNumber : 0,
+                 /* columnNumber*/ 0,
+                 /* flags*/ Ci.nsIScriptError.warningFlag,
+                 /* category*/ "chrome javascript");
+      Services.console.logMessage(error);
+
+      if (Preferences.get("dom.ipc.shims.dumpWarnings", false)) {
+        dump(message + "\n");
+        while (stack) {
+          dump(stack + "\n");
+          stack = stack.caller;
+        }
+        dump("\n");
+      }
+    };
+  },
+
+  warn: function(msg, addon, warning) {
+    let delayed = this.delayedWarning(msg, addon, warning);
+    delayed();
+  },
+
+  warnings: {
+    content: section(1, "#gBrowser.contentWindow.2C_window.content..."),
+    limitations_of_CPOWs: section(2, "#Limitations_of_CPOWs"),
+    nsIContentPolicy: section(3, "#nsIContentPolicy"),
+    nsIWebProgressListener: section(4, "#nsIWebProgressListener"),
+    observers: section(5, "#Observers_in_the_chrome_process"),
+    DOM_events: section(6, "#DOM_Events"),
+    sandboxes: section(7, "#Sandboxes"),
+    JSMs: section(8, "#JavaScript_code_modules_(JSMs)"),
+    nsIAboutModule: section(9, "#nsIAboutModule"),
+    // If more than 14 values appear here, you need to change the
+    // ADDON_SHIM_USAGE histogram definition in Histograms.json.
+  },
+};