Backed out changeset b1fe3750580d (bug 1471989) for build bustages on a CLOSED TREE

dom/base/WindowDestroyedEvent.cpp

@@ -109,9 +109,6 @@ WindowDestroyedEvent::Run() {
         JS::Rooted<JSObject*> obj(cx, currentInner->FastGetGlobalJSObject());
         if (obj && !js::IsSystemRealm(js::GetNonCCWObjectRealm(obj))) {
           JS::Realm* realm = js::GetNonCCWObjectRealm(obj);
-
-          xpc::NukeJSStackFrames(realm);
-
           nsCOMPtr<nsIPrincipal> pc =
               nsJSPrincipals::get(JS::GetRealmPrincipals(realm));
 

dom/bindings/Exceptions.cpp

@@ -10,7 +10,6 @@
 #include "js/TypeDecls.h"
 #include "jsapi.h"
 #include "js/SavedFrameAPI.h"
-#include "xpcpublic.h"
 #include "mozilla/CycleCollectedJSContext.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/DOMException.h"
@@ -198,7 +197,7 @@ already_AddRefed<nsIStackFrame> GetCurrentJSStack(int32_t aMaxDepth) {
 
 namespace exceptions {
 
-class JSStackFrame final : public nsIStackFrame, public xpc::JSStackFrameBase {
+class JSStackFrame : public nsIStackFrame {
  public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(JSStackFrame)
@@ -210,12 +209,6 @@ class JSStackFrame final : public nsIStackFrame, public xpc::JSStackFrameBase {
  private:
   virtual ~JSStackFrame();
 
-  void Clear() override { mStack = nullptr; }
-
-  // Remove this frame from the per-realm list of live frames,
-  // and clear out the stack pointer.
-  void UnregisterAndClear();
-
   JS::Heap<JSObject*> mStack;
   nsString mFormattedStack;
 
@@ -253,29 +246,15 @@ JSStackFrame::JSStackFrame(JS::Handle<JSObject*> aStack)
   MOZ_ASSERT(JS::IsUnwrappedSavedFrame(mStack));
 
   mozilla::HoldJSObjects(this);
-
-  xpc::RegisterJSStackFrame(js::GetNonCCWObjectRealm(aStack), this);
 }
 
-JSStackFrame::~JSStackFrame() {
-  UnregisterAndClear();
-  mozilla::DropJSObjects(this);
-}
-
-void JSStackFrame::UnregisterAndClear() {
-  if (!mStack) {
-    return;
-  }
-
-  xpc::UnregisterJSStackFrame(js::GetNonCCWObjectRealm(mStack), this);
-  Clear();
-}
+JSStackFrame::~JSStackFrame() { mozilla::DropJSObjects(this); }
 
 NS_IMPL_CYCLE_COLLECTION_CLASS(JSStackFrame)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(JSStackFrame)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCaller)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mAsyncCaller)
-  tmp->UnregisterAndClear();
+  tmp->mStack = nullptr;
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(JSStackFrame)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCaller)

js/xpconnect/src/XPCJSRuntime.cpp

@@ -382,51 +382,6 @@ static bool PrincipalImmuneToScriptPolicy(nsIPrincipal* aPrincipal) {
   return false;
 }
 
-void RealmPrivate::RegisterStackFrame(JSStackFrameBase* aFrame) {
-  mJSStackFrames.PutEntry(aFrame);
-}
-
-void RealmPrivate::UnregisterStackFrame(JSStackFrameBase* aFrame) {
-  mJSStackFrames.RemoveEntry(aFrame);
-}
-
-void RealmPrivate::NukeJSStackFrames() {
-  for (auto iter = mJSStackFrames.Iter(); !iter.Done(); iter.Next()) {
-    iter.Get()->GetKey()->Clear();
-  }
-
-  mJSStackFrames.Clear();
-}
-
-void xpc::RegisterJSStackFrame(JS::Realm* aRealm,
-                               JSStackFrameBase* aStackFrame) {
-  RealmPrivate* realmPrivate = RealmPrivate::Get(aRealm);
-  if (!realmPrivate) {
-    return;
-  }
-
-  realmPrivate->RegisterStackFrame(aStackFrame);
-}
-
-void xpc::UnregisterJSStackFrame(JS::Realm* aRealm,
-                                 JSStackFrameBase* aStackFrame) {
-  RealmPrivate* realmPrivate = RealmPrivate::Get(aRealm);
-  if (!realmPrivate) {
-    return;
-  }
-
-  realmPrivate->UnregisterStackFrame(aStackFrame);
-}
-
-void xpc::NukeJSStackFrames(JS::Realm* aRealm) {
-  RealmPrivate* realmPrivate = RealmPrivate::Get(aRealm);
-  if (!realmPrivate) {
-    return;
-  }
-
-  realmPrivate->NukeJSStackFrames();
-}
-
 Scriptability::Scriptability(JS::Realm* realm)
     : mScriptBlocks(0),
       mDocShellAllowsScript(true),

js/xpconnect/src/xpcprivate.h

@@ -2915,19 +2915,11 @@ class RealmPrivate {
     locationURI = aLocationURI;
   }
 
-  // JSStackFrames are tracked on a per-realm basis so they
-  // can be cleared when the associated window goes away.
-  void RegisterStackFrame(JSStackFrameBase* aFrame);
-  void UnregisterStackFrame(JSStackFrameBase* aFrame);
-  void NukeJSStackFrames();
-
  private:
   nsCString location;
   nsCOMPtr<nsIURI> locationURI;
 
   bool TryParseLocationURI(LocationHint aType, nsIURI** aURI);
-
-  nsTHashtable<nsPtrHashKey<JSStackFrameBase>> mJSStackFrames;
 };
 
 inline XPCWrappedNativeScope* ObjectScope(JSObject* obj) {

js/xpconnect/src/xpcpublic.h

@@ -714,15 +714,6 @@ bool IfaceID2JSValue(JSContext* aCx, const nsXPTInterfaceInfo& aInfo,
 bool ContractID2JSValue(JSContext* aCx, JSString* aContract,
                         JS::MutableHandleValue aVal);
 
-class JSStackFrameBase {
- public:
-  virtual void Clear() = 0;
-};
-
-void RegisterJSStackFrame(JS::Realm* aRealm, JSStackFrameBase* aStackFrame);
-void UnregisterJSStackFrame(JS::Realm* aRealm, JSStackFrameBase* aStackFrame);
-void NukeJSStackFrames(JS::Realm* aRealm);
-
 }  // namespace xpc
 
 namespace mozilla {

js/xpconnect/tests/browser/browser.ini

@@ -1,6 +1,4 @@
 [DEFAULT]
 support-files =
-  browser_consoleStack.html
   browser_deadObjectOnUnload.html
 [browser_dead_object.js]
-[browser_exception_leak.js]

js/xpconnect/tests/browser/browser_consoleStack.html

@@ -1,21 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<!--
-Test page for https://bugzilla.mozilla.org/show_bug.cgi?id=1471989
--->
-<head>
-  <meta charset="utf-8">
-  <title>Test page for Bug 1471989</title>
-</head>
-<body onUnload="onUnload();">
-<p><span id="samplepage">sample page</span></p>
-<script type="application/javascript">
-  // Get something sent to ConsoleStorageAPI that has a stack.
-  console.trace("whatever");
-
-  function onUnload() {
-    console.log('in unload');
-  }
-</script>
-</body>
-</html>

js/xpconnect/tests/browser/browser_exception_leak.js

@@ -1,52 +0,0 @@
-/* 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/.
- */
-
-// For bug 1471989, test that an exception saved by chrome code can't leak the page.
-
-add_task(async function test() {
-  const url = "http://mochi.test:8888/browser/js/xpconnect/tests/browser/browser_consoleStack.html";
-  let newTab = await BrowserTestUtils.openNewForegroundTab(gBrowser, url);
-  let browser = gBrowser.selectedBrowser;
-  let innerWindowId = browser.innerWindowID;
-
-  let stackTraceEmpty = await ContentTask.spawn(browser, {innerWindowId}, async function(args) {
-    let {TestUtils} = ChromeUtils.import("resource://testing-common/TestUtils.jsm", {});
-    let {Assert} = ChromeUtils.import("resource://testing-common/Assert.jsm", {});
-
-    const ConsoleAPIStorage = Cc["@mozilla.org/consoleAPI-storage;1"].getService(Ci.nsIConsoleAPIStorage);
-    let consoleEvents = ConsoleAPIStorage.getEvents(args.innerWindowId);
-    Assert.equal(consoleEvents.length, 1, "Should only be one console event for the window");
-
-    // Intentionally hold a reference to the console event.
-    let leakedConsoleEvent = consoleEvents[0];
-
-    let doc = content.document;
-    let promise = TestUtils.topicObserved("inner-window-nuked", (subject, data) => {
-      let id = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
-      return id == args.innerWindowId;
-    });
-    content.location = "http://example.org/";
-    await promise;
-
-    // This string should be empty. For that to happen, two things
-    // need to be true:
-    //
-    // a) ConsoleCallData::mStack is not null. This means that the
-    // stack trace was not reified before the page was nuked. If it
-    // was, then the correct |filename| value would be stored on the
-    // object. (This is not a problem, except that it stops us from
-    // testing the next condition.)
-    //
-    // b) ConsoleData::mStack.mStack is null. This means that the
-    // JSStackFrame is keeping alive the JS object in the page after
-    // the page was nuked, which leaks the page.
-    return leakedConsoleEvent.stacktrace[0].filename;
-  });
-
-  is(stackTraceEmpty, "",
-     "JSStackFrame shouldn't leak mStack after window nuking");
-
-  BrowserTestUtils.removeTab(newTab);
-});