Add m-esr52 at 52.6.0

1 files changed, 833 insertions, 0 deletions

diff --git a/dom/base/ScriptSettings.cpp b/dom/base/ScriptSettings.cpp
new file mode 100644
index 000000000..d67f2167a
--- /dev/null
+++ b/dom/base/ScriptSettings.cpp
@@ -0,0 +1,833 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "mozilla/dom/ScriptSettings.h"
+#include "mozilla/ThreadLocal.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/CycleCollectedJSContext.h"
+
+#include "jsapi.h"
+#include "xpcpublic.h"
+#include "nsIGlobalObject.h"
+#include "nsIDocShell.h"
+#include "nsIScriptGlobalObject.h"
+#include "nsIScriptContext.h"
+#include "nsContentUtils.h"
+#include "nsGlobalWindow.h"
+#include "nsPIDOMWindow.h"
+#include "nsTArray.h"
+#include "nsJSUtils.h"
+#include "nsDOMJSUtils.h"
+#include "WorkerPrivate.h"
+
+namespace mozilla {
+namespace dom {
+
+static MOZ_THREAD_LOCAL(ScriptSettingsStackEntry*) sScriptSettingsTLS;
+static bool sScriptSettingsTLSInitialized;
+
+class ScriptSettingsStack {
+public:
+  static ScriptSettingsStackEntry* Top() {
+    return sScriptSettingsTLS.get();
+  }
+
+  static void Push(ScriptSettingsStackEntry *aEntry) {
+    MOZ_ASSERT(!aEntry->mOlder);
+    // Whenever JSAPI use is disabled, the next stack entry pushed must
+    // not be an AutoIncumbentScript.
+    MOZ_ASSERT_IF(!Top() || Top()->NoJSAPI(),
+                  !aEntry->IsIncumbentScript());
+    // Whenever the top entry is not an incumbent canidate, the next stack entry
+    // pushed must not be an AutoIncumbentScript.
+    MOZ_ASSERT_IF(Top() && !Top()->IsIncumbentCandidate(),
+                  !aEntry->IsIncumbentScript());
+
+    aEntry->mOlder = Top();
+    sScriptSettingsTLS.set(aEntry);
+  }
+
+  static void Pop(ScriptSettingsStackEntry *aEntry) {
+    MOZ_ASSERT(aEntry == Top());
+    sScriptSettingsTLS.set(aEntry->mOlder);
+  }
+
+  static nsIGlobalObject* IncumbentGlobal() {
+    ScriptSettingsStackEntry *entry = Top();
+    while (entry) {
+      if (entry->IsIncumbentCandidate()) {
+        return entry->mGlobalObject;
+      }
+      entry = entry->mOlder;
+    }
+    return nullptr;
+  }
+
+  static ScriptSettingsStackEntry* EntryPoint() {
+    ScriptSettingsStackEntry *entry = Top();
+    while (entry) {
+      if (entry->IsEntryCandidate()) {
+        return entry;
+      }
+      entry = entry->mOlder;
+    }
+    return nullptr;
+  }
+
+  static nsIGlobalObject* EntryGlobal() {
+    ScriptSettingsStackEntry *entry = EntryPoint();
+    if (!entry) {
+      return nullptr;
+    }
+    return entry->mGlobalObject;
+  }
+
+#ifdef DEBUG
+  static ScriptSettingsStackEntry* TopNonIncumbentScript() {
+    ScriptSettingsStackEntry *entry = Top();
+    while (entry) {
+      if (!entry->IsIncumbentScript()) {
+        return entry;
+      }
+      entry = entry->mOlder;
+    }
+    return nullptr;
+  }
+#endif // DEBUG
+
+};
+
+static unsigned long gRunToCompletionListeners = 0;
+
+void
+UseEntryScriptProfiling()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  ++gRunToCompletionListeners;
+}
+
+void
+UnuseEntryScriptProfiling()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(gRunToCompletionListeners > 0);
+  --gRunToCompletionListeners;
+}
+
+void
+InitScriptSettings()
+{
+  bool success = sScriptSettingsTLS.init();
+  if (!success) {
+    MOZ_CRASH();
+  }
+
+  sScriptSettingsTLS.set(nullptr);
+  sScriptSettingsTLSInitialized = true;
+}
+
+void
+DestroyScriptSettings()
+{
+  MOZ_ASSERT(sScriptSettingsTLS.get() == nullptr);
+}
+
+bool
+ScriptSettingsInitialized()
+{
+  return sScriptSettingsTLSInitialized;
+}
+
+ScriptSettingsStackEntry::ScriptSettingsStackEntry(nsIGlobalObject *aGlobal,
+                                                   Type aType)
+  : mGlobalObject(aGlobal)
+  , mType(aType)
+  , mOlder(nullptr)
+{
+  MOZ_ASSERT_IF(IsIncumbentCandidate() && !NoJSAPI(), mGlobalObject);
+  MOZ_ASSERT(!mGlobalObject || mGlobalObject->GetGlobalJSObject(),
+             "Must have an actual JS global for the duration on the stack");
+  MOZ_ASSERT(!mGlobalObject ||
+             JS_IsGlobalObject(mGlobalObject->GetGlobalJSObject()),
+             "No outer windows allowed");
+}
+
+ScriptSettingsStackEntry::~ScriptSettingsStackEntry()
+{
+  // We must have an actual JS global for the entire time this is on the stack.
+  MOZ_ASSERT_IF(mGlobalObject, mGlobalObject->GetGlobalJSObject());
+}
+
+// If the entry or incumbent global ends up being something that the subject
+// principal doesn't subsume, we don't want to use it. This never happens on
+// the web, but can happen with asymmetric privilege relationships (i.e.
+// nsExpandedPrincipal and System Principal).
+//
+// The most correct thing to use instead would be the topmost global on the
+// callstack whose principal is subsumed by the subject principal. But that's
+// hard to compute, so we just substitute the global of the current
+// compartment. In practice, this is fine.
+//
+// Note that in particular things like:
+//
+// |SpecialPowers.wrap(crossOriginWindow).eval(open())|
+//
+// trigger this case. Although both the entry global and the current global
+// have normal principals, the use of Gecko-specific System-Principaled JS
+// puts the code from two different origins on the callstack at once, which
+// doesn't happen normally on the web.
+static nsIGlobalObject*
+ClampToSubject(nsIGlobalObject* aGlobalOrNull)
+{
+  if (!aGlobalOrNull || !NS_IsMainThread()) {
+    return aGlobalOrNull;
+  }
+
+  nsIPrincipal* globalPrin = aGlobalOrNull->PrincipalOrNull();
+  NS_ENSURE_TRUE(globalPrin, GetCurrentGlobal());
+  if (!nsContentUtils::SubjectPrincipalOrSystemIfNativeCaller()->SubsumesConsideringDomain(globalPrin)) {
+    return GetCurrentGlobal();
+  }
+
+  return aGlobalOrNull;
+}
+
+nsIGlobalObject*
+GetEntryGlobal()
+{
+  return ClampToSubject(ScriptSettingsStack::EntryGlobal());
+}
+
+nsIDocument*
+GetEntryDocument()
+{
+  nsIGlobalObject* global = GetEntryGlobal();
+  nsCOMPtr<nsPIDOMWindowInner> entryWin = do_QueryInterface(global);
+
+  // If our entry global isn't a window, see if it's an addon scope associated
+  // with a window. If it is, the caller almost certainly wants that rather
+  // than null.
+  if (!entryWin && global) {
+    if (auto* win = xpc::AddonWindowOrNull(global->GetGlobalJSObject())) {
+      entryWin = win->AsInner();
+    }
+  }
+
+  return entryWin ? entryWin->GetExtantDoc() : nullptr;
+}
+
+nsIGlobalObject*
+GetIncumbentGlobal()
+{
+  // We need the current JSContext in order to check the JS for
+  // scripted frames that may have appeared since anyone last
+  // manipulated the stack. If it's null, that means that there
+  // must be no entry global on the stack, and therefore no incumbent
+  // global either.
+  JSContext *cx = nsContentUtils::GetCurrentJSContextForThread();
+  if (!cx) {
+    MOZ_ASSERT(ScriptSettingsStack::EntryGlobal() == nullptr);
+    return nullptr;
+  }
+
+  // See what the JS engine has to say. If we've got a scripted caller
+  // override in place, the JS engine will lie to us and pretend that
+  // there's nothing on the JS stack, which will cause us to check the
+  // incumbent script stack below.
+  if (JSObject *global = JS::GetScriptedCallerGlobal(cx)) {
+    return ClampToSubject(xpc::NativeGlobal(global));
+  }
+
+  // Ok, nothing from the JS engine. Let's use whatever's on the
+  // explicit stack.
+  return ClampToSubject(ScriptSettingsStack::IncumbentGlobal());
+}
+
+nsIGlobalObject*
+GetCurrentGlobal()
+{
+  JSContext *cx = nsContentUtils::GetCurrentJSContextForThread();
+  if (!cx) {
+    return nullptr;
+  }
+
+  JSObject *global = JS::CurrentGlobalOrNull(cx);
+  if (!global) {
+    return nullptr;
+  }
+
+  return xpc::NativeGlobal(global);
+}
+
+nsIPrincipal*
+GetWebIDLCallerPrincipal()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  ScriptSettingsStackEntry *entry = ScriptSettingsStack::EntryPoint();
+
+  // If we have an entry point that is not NoJSAPI, we know it must be an
+  // AutoEntryScript.
+  if (!entry || entry->NoJSAPI()) {
+    return nullptr;
+  }
+  AutoEntryScript* aes = static_cast<AutoEntryScript*>(entry);
+
+  return aes->mWebIDLCallerPrincipal;
+}
+
+bool
+IsJSAPIActive()
+{
+  ScriptSettingsStackEntry* topEntry = ScriptSettingsStack::Top();
+  return topEntry && !topEntry->NoJSAPI();
+}
+
+namespace danger {
+JSContext*
+GetJSContext()
+{
+  return CycleCollectedJSContext::Get()->Context();
+}
+} // namespace danger
+
+JS::RootingContext*
+RootingCx()
+{
+  return CycleCollectedJSContext::Get()->RootingCx();
+}
+
+AutoJSAPI::AutoJSAPI()
+  : ScriptSettingsStackEntry(nullptr, eJSAPI)
+  , mCx(nullptr)
+  , mIsMainThread(false) // For lack of anything better
+{
+}
+
+AutoJSAPI::~AutoJSAPI()
+{
+  if (!mCx) {
+    // No need to do anything here: we never managed to Init, so can't have an
+    // exception on our (nonexistent) JSContext.  We also don't need to restore
+    // any state on it.  Finally, we never made it to pushing outselves onto the
+    // ScriptSettingsStack, so shouldn't pop.
+    MOZ_ASSERT(ScriptSettingsStack::Top() != this);
+    return;
+  }
+
+  ReportException();
+
+  if (mOldWarningReporter.isSome()) {
+    JS::SetWarningReporter(cx(), mOldWarningReporter.value());
+  }
+
+  // Leave the request before popping.
+  if (mIsMainThread) {
+    mAutoRequest.reset();
+  }
+
+  ScriptSettingsStack::Pop(this);
+}
+
+void
+WarningOnlyErrorReporter(JSContext* aCx, JSErrorReport* aRep);
+
+void
+AutoJSAPI::InitInternal(nsIGlobalObject* aGlobalObject, JSObject* aGlobal,
+                        JSContext* aCx, bool aIsMainThread)
+{
+  MOZ_ASSERT(aCx);
+  MOZ_ASSERT(aCx == danger::GetJSContext());
+  MOZ_ASSERT(aIsMainThread == NS_IsMainThread());
+  MOZ_ASSERT(bool(aGlobalObject) == bool(aGlobal));
+  MOZ_ASSERT_IF(aGlobalObject, aGlobalObject->GetGlobalJSObject() == aGlobal);
+#ifdef DEBUG
+  bool haveException = JS_IsExceptionPending(aCx);
+#endif // DEBUG
+
+  mCx = aCx;
+  mIsMainThread = aIsMainThread;
+  mGlobalObject = aGlobalObject;
+  if (aIsMainThread) {
+    // We _could_ just unconditionally emplace mAutoRequest here.  It's just not
+    // needed on worker threads, and we're hoping to kill it on the main thread
+    // too.
+    mAutoRequest.emplace(mCx);
+  }
+  if (aGlobal) {
+    JS::ExposeObjectToActiveJS(aGlobal);
+  }
+  mAutoNullableCompartment.emplace(mCx, aGlobal);
+
+  ScriptSettingsStack::Push(this);
+
+  mOldWarningReporter.emplace(JS::GetWarningReporter(aCx));
+
+  JS::SetWarningReporter(aCx, WarningOnlyErrorReporter);
+
+#ifdef DEBUG
+  if (haveException) {
+    JS::Rooted<JS::Value> exn(aCx);
+    JS_GetPendingException(aCx, &exn);
+
+    JS_ClearPendingException(aCx);
+    if (exn.isObject()) {
+      JS::Rooted<JSObject*> exnObj(aCx, &exn.toObject());
+
+      nsAutoJSString stack, filename, name, message;
+      int32_t line;
+
+      JS::Rooted<JS::Value> tmp(aCx);
+      if (!JS_GetProperty(aCx, exnObj, "filename", &tmp)) {
+        JS_ClearPendingException(aCx);
+      }
+      if (tmp.isUndefined()) {
+        if (!JS_GetProperty(aCx, exnObj, "fileName", &tmp)) {
+          JS_ClearPendingException(aCx);
+        }
+      }
+
+      if (!filename.init(aCx, tmp)) {
+        JS_ClearPendingException(aCx);
+      }
+
+      if (!JS_GetProperty(aCx, exnObj, "stack", &tmp) ||
+          !stack.init(aCx, tmp)) {
+        JS_ClearPendingException(aCx);
+      }
+
+      if (!JS_GetProperty(aCx, exnObj, "name", &tmp) ||
+          !name.init(aCx, tmp)) {
+        JS_ClearPendingException(aCx);
+      }
+
+      if (!JS_GetProperty(aCx, exnObj, "message", &tmp) ||
+          !message.init(aCx, tmp)) {
+        JS_ClearPendingException(aCx);
+      }
+
+      if (!JS_GetProperty(aCx, exnObj, "lineNumber", &tmp) ||
+          !JS::ToInt32(aCx, tmp, &line)) {
+        JS_ClearPendingException(aCx);
+        line = 0;
+      }
+
+      printf_stderr("PREEXISTING EXCEPTION OBJECT: '%s: %s'\n%s:%d\n%s\n",
+                    NS_ConvertUTF16toUTF8(name).get(),
+                    NS_ConvertUTF16toUTF8(message).get(),
+                    NS_ConvertUTF16toUTF8(filename).get(), line,
+                    NS_ConvertUTF16toUTF8(stack).get());
+    } else {
+      // It's a primitive... not much we can do other than stringify it.
+      nsAutoJSString exnStr;
+      if (!exnStr.init(aCx, exn)) {
+        JS_ClearPendingException(aCx);
+      }
+
+      printf_stderr("PREEXISTING EXCEPTION PRIMITIVE: %s\n",
+                    NS_ConvertUTF16toUTF8(exnStr).get());
+    }
+    MOZ_ASSERT(false, "We had an exception; we should not have");
+  }
+#endif // DEBUG
+}
+
+AutoJSAPI::AutoJSAPI(nsIGlobalObject* aGlobalObject,
+                     bool aIsMainThread,
+                     Type aType)
+  : ScriptSettingsStackEntry(aGlobalObject, aType)
+  , mIsMainThread(aIsMainThread)
+{
+  MOZ_ASSERT(aGlobalObject);
+  MOZ_ASSERT(aGlobalObject->GetGlobalJSObject(), "Must have a JS global");
+  MOZ_ASSERT(aIsMainThread == NS_IsMainThread());
+
+  InitInternal(aGlobalObject, aGlobalObject->GetGlobalJSObject(),
+               danger::GetJSContext(), aIsMainThread);
+}
+
+void
+AutoJSAPI::Init()
+{
+  MOZ_ASSERT(!mCx, "An AutoJSAPI should only be initialised once");
+
+  InitInternal(/* aGlobalObject */ nullptr, /* aGlobal */ nullptr,
+               danger::GetJSContext(), NS_IsMainThread());
+}
+
+bool
+AutoJSAPI::Init(nsIGlobalObject* aGlobalObject, JSContext* aCx)
+{
+  MOZ_ASSERT(!mCx, "An AutoJSAPI should only be initialised once");
+  MOZ_ASSERT(aCx);
+
+  if (NS_WARN_IF(!aGlobalObject)) {
+    return false;
+  }
+
+  JSObject* global = aGlobalObject->GetGlobalJSObject();
+  if (NS_WARN_IF(!global)) {
+    return false;
+  }
+
+  InitInternal(aGlobalObject, global, aCx, NS_IsMainThread());
+  return true;
+}
+
+bool
+AutoJSAPI::Init(nsIGlobalObject* aGlobalObject)
+{
+  return Init(aGlobalObject, danger::GetJSContext());
+}
+
+bool
+AutoJSAPI::Init(JSObject* aObject)
+{
+  return Init(xpc::NativeGlobal(aObject));
+}
+
+bool
+AutoJSAPI::Init(nsPIDOMWindowInner* aWindow, JSContext* aCx)
+{
+  return Init(nsGlobalWindow::Cast(aWindow), aCx);
+}
+
+bool
+AutoJSAPI::Init(nsPIDOMWindowInner* aWindow)
+{
+  return Init(nsGlobalWindow::Cast(aWindow));
+}
+
+bool
+AutoJSAPI::Init(nsGlobalWindow* aWindow, JSContext* aCx)
+{
+  return Init(static_cast<nsIGlobalObject*>(aWindow), aCx);
+}
+
+bool
+AutoJSAPI::Init(nsGlobalWindow* aWindow)
+{
+  return Init(static_cast<nsIGlobalObject*>(aWindow));
+}
+
+// Even with autoJSAPIOwnsErrorReporting, the JS engine still sends warning
+// reports to the JSErrorReporter as soon as they are generated. These go
+// directly to the console, so we can handle them easily here.
+//
+// Eventually, SpiderMonkey will have a special-purpose callback for warnings
+// only.
+void
+WarningOnlyErrorReporter(JSContext* aCx, JSErrorReport* aRep)
+{
+  MOZ_ASSERT(JSREPORT_IS_WARNING(aRep->flags));
+  if (!NS_IsMainThread()) {
+    // Reporting a warning on workers is a bit complicated because we have to
+    // climb our parent chain until we get to the main thread.  So go ahead and
+    // just go through the worker ReportError codepath here.
+    //
+    // That said, it feels like we should be able to short-circuit things a bit
+    // here by posting an appropriate runnable to the main thread directly...
+    // Worth looking into sometime.
+    workers::WorkerPrivate* worker = workers::GetWorkerPrivateFromContext(aCx);
+    MOZ_ASSERT(worker);
+
+    worker->ReportError(aCx, JS::ConstUTF8CharsZ(), aRep);
+    return;
+  }
+
+  RefPtr<xpc::ErrorReport> xpcReport = new xpc::ErrorReport();
+  nsGlobalWindow* win = xpc::CurrentWindowOrNull(aCx);
+  if (!win) {
+    // We run addons in a separate privileged compartment, but if we're in an
+    // addon compartment we should log warnings to the console of the associated
+    // DOM Window.
+    win = xpc::AddonWindowOrNull(JS::CurrentGlobalOrNull(aCx));
+  }
+  xpcReport->Init(aRep, nullptr, nsContentUtils::IsCallerChrome(),
+                  win ? win->AsInner()->WindowID() : 0);
+  xpcReport->LogToConsole();
+}
+
+void
+AutoJSAPI::ReportException()
+{
+  if (!HasException()) {
+    return;
+  }
+
+  // AutoJSAPI uses a JSAutoNullableCompartment, and may be in a null
+  // compartment when the destructor is called. However, the JS engine
+  // requires us to be in a compartment when we fetch the pending exception.
+  // In this case, we enter the privileged junk scope and don't dispatch any
+  // error events.
+  JS::Rooted<JSObject*> errorGlobal(cx(), JS::CurrentGlobalOrNull(cx()));
+  if (!errorGlobal) {
+    if (mIsMainThread) {
+      errorGlobal = xpc::PrivilegedJunkScope();
+    } else {
+      errorGlobal = workers::GetCurrentThreadWorkerGlobal();
+    }
+  }
+  JSAutoCompartment ac(cx(), errorGlobal);
+  JS::Rooted<JS::Value> exn(cx());
+  js::ErrorReport jsReport(cx());
+  if (StealException(&exn) &&
+      jsReport.init(cx(), exn, js::ErrorReport::WithSideEffects)) {
+    if (mIsMainThread) {
+      RefPtr<xpc::ErrorReport> xpcReport = new xpc::ErrorReport();
+
+      RefPtr<nsGlobalWindow> win = xpc::WindowGlobalOrNull(errorGlobal);
+      if (!win) {
+        // We run addons in a separate privileged compartment, but they still
+        // expect to trigger the onerror handler of their associated DOM Window.
+        win = xpc::AddonWindowOrNull(errorGlobal);
+      }
+      nsPIDOMWindowInner* inner = win ? win->AsInner() : nullptr;
+      xpcReport->Init(jsReport.report(), jsReport.toStringResult().c_str(),
+                      nsContentUtils::IsCallerChrome(),
+                      inner ? inner->WindowID() : 0);
+      if (inner && jsReport.report()->errorNumber != JSMSG_OUT_OF_MEMORY) {
+        JS::RootingContext* rcx = JS::RootingContext::get(cx());
+        DispatchScriptErrorEvent(inner, rcx, xpcReport, exn);
+      } else {
+        JS::Rooted<JSObject*> stack(cx(),
+          xpc::FindExceptionStackForConsoleReport(inner, exn));
+        xpcReport->LogToConsoleWithStack(stack);
+      }
+    } else {
+      // On a worker, we just use the worker error reporting mechanism and don't
+      // bother with xpc::ErrorReport.  This will ensure that all the right
+      // events (which are a lot more complicated than in the window case) get
+      // fired.
+      workers::WorkerPrivate* worker = workers::GetCurrentThreadWorkerPrivate();
+      MOZ_ASSERT(worker);
+      MOZ_ASSERT(worker->GetJSContext() == cx());
+      // Before invoking ReportError, put the exception back on the context,
+      // because it may want to put it in its error events and has no other way
+      // to get hold of it.  After we invoke ReportError, clear the exception on
+      // cx(), just in case ReportError didn't.
+      JS_SetPendingException(cx(), exn);
+      worker->ReportError(cx(), jsReport.toStringResult(), jsReport.report());
+      ClearException();
+    }
+  } else {
+    NS_WARNING("OOMed while acquiring uncaught exception from JSAPI");
+    ClearException();
+  }
+}
+
+bool
+AutoJSAPI::PeekException(JS::MutableHandle<JS::Value> aVal)
+{
+  MOZ_ASSERT_IF(mIsMainThread, IsStackTop());
+  MOZ_ASSERT(HasException());
+  MOZ_ASSERT(js::GetContextCompartment(cx()));
+  if (!JS_GetPendingException(cx(), aVal)) {
+    return false;
+  }
+  return true;
+}
+
+bool
+AutoJSAPI::StealException(JS::MutableHandle<JS::Value> aVal)
+{
+  if (!PeekException(aVal)) {
+    return false;
+  }
+  JS_ClearPendingException(cx());
+  return true;
+}
+
+#ifdef DEBUG
+bool
+AutoJSAPI::IsStackTop() const
+{
+  return ScriptSettingsStack::TopNonIncumbentScript() == this;
+}
+#endif // DEBUG
+
+AutoEntryScript::AutoEntryScript(nsIGlobalObject* aGlobalObject,
+                                 const char *aReason,
+                                 bool aIsMainThread)
+  : AutoJSAPI(aGlobalObject, aIsMainThread, eEntryScript)
+  , mWebIDLCallerPrincipal(nullptr)
+{
+  MOZ_ASSERT(aGlobalObject);
+
+  if (aIsMainThread && gRunToCompletionListeners > 0) {
+    mDocShellEntryMonitor.emplace(cx(), aReason);
+  }
+}
+
+AutoEntryScript::AutoEntryScript(JSObject* aObject,
+                                 const char *aReason,
+                                 bool aIsMainThread)
+  : AutoEntryScript(xpc::NativeGlobal(aObject), aReason, aIsMainThread)
+{
+}
+
+AutoEntryScript::~AutoEntryScript()
+{
+  // GC when we pop a script entry point. This is a useful heuristic that helps
+  // us out on certain (flawed) benchmarks like sunspider, because it lets us
+  // avoid GCing during the timing loop.
+  JS_MaybeGC(cx());
+}
+
+AutoEntryScript::DocshellEntryMonitor::DocshellEntryMonitor(JSContext* aCx,
+                                                            const char* aReason)
+  : JS::dbg::AutoEntryMonitor(aCx)
+  , mReason(aReason)
+{
+}
+
+void
+AutoEntryScript::DocshellEntryMonitor::Entry(JSContext* aCx, JSFunction* aFunction,
+                                             JSScript* aScript, JS::Handle<JS::Value> aAsyncStack,
+                                             const char* aAsyncCause)
+{
+  JS::Rooted<JSFunction*> rootedFunction(aCx);
+  if (aFunction) {
+    rootedFunction = aFunction;
+  }
+  JS::Rooted<JSScript*> rootedScript(aCx);
+  if (aScript) {
+    rootedScript = aScript;
+  }
+
+  nsCOMPtr<nsPIDOMWindowInner> window =
+    do_QueryInterface(xpc::NativeGlobal(JS::CurrentGlobalOrNull(aCx)));
+  if (!window || !window->GetDocShell() ||
+      !window->GetDocShell()->GetRecordProfileTimelineMarkers()) {
+    return;
+  }
+
+  nsCOMPtr<nsIDocShell> docShellForJSRunToCompletion = window->GetDocShell();
+  nsString filename;
+  uint32_t lineNumber = 0;
+
+  js::AutoStableStringChars functionName(aCx);
+  if (rootedFunction) {
+    JS::Rooted<JSString*> displayId(aCx, JS_GetFunctionDisplayId(rootedFunction));
+    if (displayId) {
+      if (!functionName.initTwoByte(aCx, displayId)) {
+        JS_ClearPendingException(aCx);
+        return;
+      }
+    }
+  }
+
+  if (!rootedScript) {
+    rootedScript = JS_GetFunctionScript(aCx, rootedFunction);
+  }
+  if (rootedScript) {
+    filename = NS_ConvertUTF8toUTF16(JS_GetScriptFilename(rootedScript));
+    lineNumber = JS_GetScriptBaseLineNumber(aCx, rootedScript);
+  }
+
+  if (!filename.IsEmpty() || functionName.isTwoByte()) {
+    const char16_t* functionNameChars = functionName.isTwoByte() ?
+      functionName.twoByteChars() : nullptr;
+
+    docShellForJSRunToCompletion->NotifyJSRunToCompletionStart(mReason,
+                                                               functionNameChars,
+                                                               filename.BeginReading(),
+                                                               lineNumber, aAsyncStack,
+                                                               aAsyncCause);
+  }
+}
+
+void
+AutoEntryScript::DocshellEntryMonitor::Exit(JSContext* aCx)
+{
+  nsCOMPtr<nsPIDOMWindowInner> window =
+    do_QueryInterface(xpc::NativeGlobal(JS::CurrentGlobalOrNull(aCx)));
+  // Not really worth checking GetRecordProfileTimelineMarkers here.
+  if (window && window->GetDocShell()) {
+    nsCOMPtr<nsIDocShell> docShellForJSRunToCompletion = window->GetDocShell();
+    docShellForJSRunToCompletion->NotifyJSRunToCompletionStop();
+  }
+}
+
+AutoIncumbentScript::AutoIncumbentScript(nsIGlobalObject* aGlobalObject)
+  : ScriptSettingsStackEntry(aGlobalObject, eIncumbentScript)
+  , mCallerOverride(nsContentUtils::GetCurrentJSContextForThread())
+{
+  ScriptSettingsStack::Push(this);
+}
+
+AutoIncumbentScript::~AutoIncumbentScript()
+{
+  ScriptSettingsStack::Pop(this);
+}
+
+AutoNoJSAPI::AutoNoJSAPI()
+  : ScriptSettingsStackEntry(nullptr, eNoJSAPI)
+{
+  ScriptSettingsStack::Push(this);
+}
+
+AutoNoJSAPI::~AutoNoJSAPI()
+{
+  ScriptSettingsStack::Pop(this);
+}
+
+} // namespace dom
+
+AutoJSContext::AutoJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMPL)
+  : mCx(nullptr)
+{
+  JS::AutoSuppressGCAnalysis nogc;
+  MOZ_ASSERT(!mCx, "mCx should not be initialized!");
+  MOZ_ASSERT(NS_IsMainThread());
+
+  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+
+  if (dom::IsJSAPIActive()) {
+    mCx = dom::danger::GetJSContext();
+  } else {
+    mJSAPI.Init();
+    mCx = mJSAPI.cx();
+  }
+}
+
+AutoJSContext::operator JSContext*() const
+{
+  return mCx;
+}
+
+AutoSafeJSContext::AutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMPL)
+  : AutoJSAPI()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+
+  DebugOnly<bool> ok = Init(xpc::UnprivilegedJunkScope());
+  MOZ_ASSERT(ok,
+             "This is quite odd.  We should have crashed in the "
+             "xpc::NativeGlobal() call if xpc::UnprivilegedJunkScope() "
+             "returned null, and inited correctly otherwise!");
+}
+
+AutoSlowOperation::AutoSlowOperation(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMPL)
+  : AutoJSAPI()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+
+  Init();
+}
+
+void
+AutoSlowOperation::CheckForInterrupt()
+{
+  // JS_CheckForInterrupt expects us to be in a compartment.
+  JSAutoCompartment ac(cx(), xpc::UnprivilegedJunkScope());
+  JS_CheckForInterrupt(cx());
+}
+
+} // namespace mozilla