Bug 717749 - Part 1: Add a slow script debug handler service. (r=smaug)

browser/installer/package-manifest.in

@@ -531,6 +531,9 @@
 @BINPATH@/components/Push.manifest
 @BINPATH@/components/PushServiceLauncher.js
 
+@BINPATH@/components/SlowScriptDebug.manifest
+@BINPATH@/components/SlowScriptDebug.js
+
 #ifndef RELEASE_BUILD
 @BINPATH@/components/InterAppComm.manifest
 @BINPATH@/components/InterAppCommService.js

dom/base/SlowScriptDebug.js

@@ -0,0 +1,21 @@
+/* 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";
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+function SlowScriptDebug() { }
+
+SlowScriptDebug.prototype = {
+  classID: Components.ID("{e740ddb4-18b4-4aac-8ae1-9b0f4320769d}"),
+  classDescription: "Slow script debug handler",
+  contractID: "@mozilla.org/dom/slow-script-debug;1",
+  QueryInterface: XPCOMUtils.generateQI([Components.interfaces.nsISlowScriptDebug]),
+
+  get activationHandler()   { return this._activationHandler; },
+  set activationHandler(cb) { return this._activationHandler = cb; },
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([SlowScriptDebug]);

dom/base/SlowScriptDebug.manifest

@@ -0,0 +1,2 @@
+component {e740ddb4-18b4-4aac-8ae1-9b0f4320769d} SlowScriptDebug.js
+contract @mozilla.org/dom/slow-script-debug;1 {e740ddb4-18b4-4aac-8ae1-9b0f4320769d}

dom/base/moz.build

@@ -13,6 +13,7 @@ XPIDL_SOURCES += [
     'nsIEntropyCollector.idl',
     'nsIScriptChannel.idl',
     'nsISiteSpecificUserAgent.idl',
+    'nsISlowScriptDebug.idl',
 ]
 
 XPIDL_MODULE = 'dom'
@@ -128,6 +129,8 @@ EXTRA_COMPONENTS += [
     'ConsoleAPIStorage.js',
     'SiteSpecificUserAgent.js',
     'SiteSpecificUserAgent.manifest',
+    'SlowScriptDebug.js',
+    'SlowScriptDebug.manifest',
 ]
 
 EXTRA_JS_MODULES += [

dom/base/nsGlobalWindow.cpp

@@ -35,6 +35,7 @@
 #include "nsIScriptTimeoutHandler.h"
 #include "nsIController.h"
 #include "nsScriptNameSpaceManager.h"
+#include "nsISlowScriptDebug.h"
 #include "nsWindowMemoryReporter.h"
 #include "WindowNamedPropertiesHandler.h"
 
@@ -10769,27 +10770,43 @@ nsGlobalWindow::ShowSlowScriptDialog()
   unsigned lineno;
   bool hasFrame = JS::DescribeScriptedCaller(cx, &filename, &lineno);
 
-  bool debugPossible = hasFrame && js::CanCallContextDebugHandler(cx);
+  // Prioritize the SlowScriptDebug interface over JSD1.
-#ifdef MOZ_JSDEBUGGER
+  nsCOMPtr<nsISlowScriptDebugCallback> debugCallback;
-  // Get the debugger service if necessary.
+  bool oldDebugPossible = false;
-  if (debugPossible) {
-    bool jsds_IsOn = false;
-    const char jsdServiceCtrID[] = "@mozilla.org/js/jsd/debugger-service;1";
-    nsCOMPtr<jsdIExecutionHook> jsdHook;
-    nsCOMPtr<jsdIDebuggerService> jsds = do_GetService(jsdServiceCtrID, &rv);
 
-    // Check if there's a user for the debugger service that's 'on' for us
+  if (hasFrame) {
+    const char *debugCID = "@mozilla.org/dom/slow-script-debug;1";
+    nsCOMPtr<nsISlowScriptDebug> debugService = do_GetService(debugCID, &rv);
     if (NS_SUCCEEDED(rv)) {
-      jsds->GetDebuggerHook(getter_AddRefs(jsdHook));
+      debugService->GetActivationHandler(getter_AddRefs(debugCallback));
-      jsds->GetIsOn(&jsds_IsOn);
     }
 
-    // If there is a debug handler registered for this runtime AND
+    if (!debugCallback) {
-    // ((jsd is on AND has a hook) OR (jsd isn't on (something else debugs)))
+      oldDebugPossible = js::CanCallContextDebugHandler(cx);
-    // then something useful will be done with our request to debug.
+#ifdef MOZ_JSDEBUGGER
-    debugPossible = ((jsds_IsOn && (jsdHook != nullptr)) || !jsds_IsOn);
+      // Get the debugger service if necessary.
-  }
+      if (oldDebugPossible) {
+        bool jsds_IsOn = false;
+        const char jsdServiceCtrID[] = "@mozilla.org/js/jsd/debugger-service;1";
+        nsCOMPtr<jsdIExecutionHook> jsdHook;
+        nsCOMPtr<jsdIDebuggerService> jsds = do_GetService(jsdServiceCtrID, &rv);
+
+        // Check if there's a user for the debugger service that's 'on' for us
+        if (NS_SUCCEEDED(rv)) {
+          jsds->GetDebuggerHook(getter_AddRefs(jsdHook));
+          jsds->GetIsOn(&jsds_IsOn);
+        }
+
+        // If there is a debug handler registered for this runtime AND
+        // ((jsd is on AND has a hook) OR (jsd isn't on (something else debugs)))
+        // then something useful will be done with our request to debug.
+        oldDebugPossible = ((jsds_IsOn && (jsdHook != nullptr)) || !jsds_IsOn);
+      }
 #endif
+    }
+  }
+
+  bool showDebugButton = debugCallback || oldDebugPossible;
 
   // Get localizable strings
   nsXPIDLString title, msg, stopButton, waitButton, debugButton, neverShowDlg;
@@ -10820,7 +10837,7 @@ nsGlobalWindow::ShowSlowScriptDialog()
   }
 
 
-  if (debugPossible) {
+  if (showDebugButton) {
     tmp = nsContentUtils::GetLocalizedString(nsContentUtils::eDOM_PROPERTIES,
                                              "DebugScriptButton",
                                              debugButton);
@@ -10846,7 +10863,7 @@ nsGlobalWindow::ShowSlowScriptDialog()
 
   // GetStringFromName can return NS_OK and still give nullptr string
   if (NS_FAILED(rv) || !title || !msg || !stopButton || !waitButton ||
-      (!debugButton && debugPossible) || !neverShowDlg) {
+      (!debugButton && showDebugButton) || !neverShowDlg) {
     NS_ERROR("Failed to get localized strings.");
     return ContinueSlowScript;
   }
@@ -10876,7 +10893,7 @@ nsGlobalWindow::ShowSlowScriptDialog()
                           (nsIPrompt::BUTTON_POS_0 + nsIPrompt::BUTTON_POS_1));
 
   // Add a third button if necessary.
-  if (debugPossible)
+  if (showDebugButton)
     buttonFlags += nsIPrompt::BUTTON_TITLE_IS_STRING * nsIPrompt::BUTTON_POS_2;
 
   // Null out the operation callback while we're re-entering JS here.
@@ -10893,8 +10910,15 @@ nsGlobalWindow::ShowSlowScriptDialog()
   if (NS_SUCCEEDED(rv) && (buttonPressed == 0)) {
     return neverShowDlgChk ? AlwaysContinueSlowScript : ContinueSlowScript;
   }
-  if ((buttonPressed == 2) && debugPossible) {
+  if (buttonPressed == 2) {
-    return js_CallContextDebugHandler(cx) ? ContinueSlowScript : KillSlowScript;
+    if (debugCallback) {
+      rv = debugCallback->HandleSlowScriptDebug(this);
+      return NS_SUCCEEDED(rv) ? ContinueSlowScript : KillSlowScript;
+    }
+
+    if (oldDebugPossible) {
+      return js_CallContextDebugHandler(cx) ? ContinueSlowScript : KillSlowScript;
+    }
   }
   JS_ClearPendingException(cx);
   return KillSlowScript;

dom/base/nsISlowScriptDebug.idl

@@ -0,0 +1,19 @@
+/* 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/. */
+
+#include "nsISupports.idl"
+
+interface nsIDOMWindow;
+
+[scriptable, function, uuid(f7dbb80c-5d1e-4fd9-b55c-a9ffda4a75b1)]
+interface nsISlowScriptDebugCallback : nsISupports
+{
+  void handleSlowScriptDebug(in nsIDOMWindow aWindow);
+};
+
+[scriptable, uuid(f75d4164-3aa7-4395-ba44-a5f95b2e8427)]
+interface nsISlowScriptDebug : nsISupports
+{
+  attribute nsISlowScriptDebugCallback activationHandler;
+};