1 files changed, 160 insertions, 0 deletions
diff --git a/dom/script/AutoEntryScript.cpp b/dom/script/AutoEntryScript.cpp
new file mode 100644
index 0000000000..f1afa25b48
--- /dev/null
+++ b/dom/script/AutoEntryScript.cpp
@@ -0,0 +1,160 @@
+/* -*- 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/AutoEntryScript.h"
+
+#include <stdint.h>
+#include <utility>
+#include "js/ProfilingCategory.h"
+#include "js/ProfilingStack.h"
+#include "jsapi.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Span.h"
+#include "nsCOMPtr.h"
+#include "nsContentUtils.h"
+#include "nsGlobalWindowInner.h"
+#include "nsIDocShell.h"
+#include "nsJSUtils.h"
+#include "nsPIDOMWindow.h"
+#include "nsPIDOMWindowInlines.h"
+#include "nsString.h"
+#include "xpcpublic.h"
+
+namespace mozilla::dom {
+
+namespace {
+// Assert if it's not safe to run script. The helper class
+// AutoAllowLegacyScriptExecution allows to allow-list
+// legacy cases where it's actually not safe to run script.
+#ifdef DEBUG
+void AssertIfNotSafeToRunScript() {
+  // if it's safe to run script, then there is nothing to do here.
+  if (nsContentUtils::IsSafeToRunScript()) {
+    return;
+  }
+
+  // auto allowing legacy script execution is fine for now.
+  if (AutoAllowLegacyScriptExecution::IsAllowed()) {
+    return;
+  }
+
+  MOZ_ASSERT(false, "is it safe to run script?");
+}
+#endif
+
+static unsigned long gRunToCompletionListeners = 0;
+
+}  // namespace
+
+void UseEntryScriptProfiling() {
+  MOZ_ASSERT(NS_IsMainThread());
+  ++gRunToCompletionListeners;
+}
+
+void UnuseEntryScriptProfiling() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(gRunToCompletionListeners > 0);
+  --gRunToCompletionListeners;
+}
+
+AutoEntryScript::AutoEntryScript(nsIGlobalObject* aGlobalObject,
+                                 const char* aReason, bool aIsMainThread)
+    : AutoJSAPI(aGlobalObject, aIsMainThread, eEntryScript),
+      mWebIDLCallerPrincipal(nullptr)
+      // This relies on us having a cx() because the AutoJSAPI constructor
+      // already ran.
+      ,
+      mCallerOverride(cx()),
+      mAutoProfilerLabel(
+          "", aReason, JS::ProfilingCategoryPair::JS,
+          uint32_t(js::ProfilingStackFrame::Flags::RELEVANT_FOR_JS)),
+      mJSThreadExecution(aGlobalObject, aIsMainThread) {
+  MOZ_ASSERT(aGlobalObject);
+
+  if (aIsMainThread) {
+#ifdef DEBUG
+    AssertIfNotSafeToRunScript();
+#endif
+    if (gRunToCompletionListeners > 0) {
+      mDocShellEntryMonitor.emplace(cx(), aReason);
+    }
+    mScriptActivity.emplace(true);
+  }
+}
+
+AutoEntryScript::AutoEntryScript(JSObject* aObject, const char* aReason,
+                                 bool aIsMainThread)
+    : AutoEntryScript(xpc::NativeGlobal(aObject), aReason, aIsMainThread) {
+  // xpc::NativeGlobal uses JS::GetNonCCWObjectGlobal, which asserts that
+  // aObject is not a CCW.
+}
+
+AutoEntryScript::~AutoEntryScript() = default;
+
+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 = xpc::CurrentWindowOrNull(aCx);
+  if (!window || !window->GetDocShell() ||
+      !window->GetDocShell()->GetRecordProfileTimelineMarkers()) {
+    return;
+  }
+
+  nsCOMPtr<nsIDocShell> docShellForJSRunToCompletion = window->GetDocShell();
+
+  nsAutoJSString functionName;
+  if (rootedFunction) {
+    JS::Rooted<JSString*> displayId(aCx,
+                                    JS_GetFunctionDisplayId(rootedFunction));
+    if (displayId) {
+      if (!functionName.init(aCx, displayId)) {
+        JS_ClearPendingException(aCx);
+        return;
+      }
+    }
+  }
+
+  nsString filename;
+  uint32_t lineNumber = 0;
+  if (!rootedScript) {
+    rootedScript = JS_GetFunctionScript(aCx, rootedFunction);
+  }
+  if (rootedScript) {
+    CopyUTF8toUTF16(MakeStringSpan(JS_GetScriptFilename(rootedScript)),
+                    filename);
+    lineNumber = JS_GetScriptBaseLineNumber(aCx, rootedScript);
+  }
+
+  if (!filename.IsEmpty() || !functionName.IsEmpty()) {
+    docShellForJSRunToCompletion->NotifyJSRunToCompletionStart(
+        mReason, functionName, filename, lineNumber, aAsyncStack, aAsyncCause);
+  }
+}
+
+void AutoEntryScript::DocshellEntryMonitor::Exit(JSContext* aCx) {
+  nsCOMPtr<nsPIDOMWindowInner> window = xpc::CurrentWindowOrNull(aCx);
+  // Not really worth checking GetRecordProfileTimelineMarkers here.
+  if (window && window->GetDocShell()) {
+    nsCOMPtr<nsIDocShell> docShellForJSRunToCompletion = window->GetDocShell();
+    docShellForJSRunToCompletion->NotifyJSRunToCompletionStop();
+  }
+}
+
+}  // namespace mozilla::dom