1 files changed, 835 insertions, 0 deletions

diff --git a/js/xpconnect/src/xpcpublic.h b/js/xpconnect/src/xpcpublic.h
new file mode 100644
index 0000000000..970912aad7
--- /dev/null
+++ b/js/xpconnect/src/xpcpublic.h
@@ -0,0 +1,835 @@
+/* -*- 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/. */
+
+#ifndef xpcpublic_h
+#define xpcpublic_h
+
+#include <cstddef>
+#include <cstdint>
+#include "ErrorList.h"
+#include "js/BuildId.h"
+#include "js/ErrorReport.h"
+#include "js/GCAPI.h"
+#include "js/Object.h"
+#include "js/RootingAPI.h"
+#include "js/String.h"
+#include "js/TypeDecls.h"
+#include "js/Utility.h"
+#include "js/Value.h"
+#include "jsapi.h"
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/dom/DOMString.h"
+#include "mozilla/fallible.h"
+#include "nsAtom.h"
+#include "nsCOMPtr.h"
+#include "nsISupports.h"
+#include "nsIURI.h"
+#include "nsStringBuffer.h"
+#include "nsStringFwd.h"
+#include "nsTArray.h"
+#include "nsWrapperCache.h"
+
+// XXX only for NukeAllWrappersForRealm, which is only used in
+// dom/base/WindowDestroyedEvent.cpp outside of js
+#include "jsfriendapi.h"
+
+class JSObject;
+class JSString;
+class JSTracer;
+class nsGlobalWindowInner;
+class nsIGlobalObject;
+class nsIHandleReportCallback;
+class nsIPrincipal;
+class nsPIDOMWindowInner;
+struct JSContext;
+struct nsID;
+struct nsXPTInterfaceInfo;
+
+namespace JS {
+class Compartment;
+class ContextOptions;
+class Realm;
+class RealmOptions;
+class Value;
+struct RuntimeStats;
+}  // namespace JS
+
+namespace mozilla {
+class BasePrincipal;
+
+namespace dom {
+class Exception;
+}  // namespace dom
+}  // namespace mozilla
+
+using xpcGCCallback = void (*)(JSGCStatus);
+
+namespace xpc {
+
+class Scriptability {
+ public:
+  explicit Scriptability(JS::Realm* realm);
+  bool Allowed();
+  bool IsImmuneToScriptPolicy();
+
+  void Block();
+  void Unblock();
+  void SetWindowAllowsScript(bool aAllowed);
+
+  static Scriptability& Get(JSObject* aScope);
+
+  // Returns true if scripting is allowed, false otherwise (if no Scriptability
+  // exists, like for example inside a ShadowRealm global, then script execution
+  // is assumed to be allowed)
+  static bool AllowedIfExists(JSObject* aScope);
+
+ private:
+  // Whenever a consumer wishes to prevent script from running on a global,
+  // it increments this value with a call to Block(). When it wishes to
+  // re-enable it (if ever), it decrements this value with a call to Unblock().
+  // Script may not run if this value is non-zero.
+  uint32_t mScriptBlocks;
+
+  // Whether the DOM window allows javascript in this scope. If this scope
+  // doesn't have a window, this value is always true.
+  bool mWindowAllowsScript;
+
+  // Whether this scope is immune to user-defined or addon-defined script
+  // policy.
+  bool mImmuneToScriptPolicy;
+
+  // Whether the new-style domain policy when this compartment was created
+  // forbids script execution.
+  bool mScriptBlockedByPolicy;
+};
+
+JSObject* TransplantObject(JSContext* cx, JS::Handle<JSObject*> origobj,
+                           JS::Handle<JSObject*> target);
+
+JSObject* TransplantObjectRetainingXrayExpandos(JSContext* cx,
+                                                JS::Handle<JSObject*> origobj,
+                                                JS::Handle<JSObject*> target);
+
+// If origObj has an xray waiver, nuke it before transplant.
+JSObject* TransplantObjectNukingXrayWaiver(JSContext* cx,
+                                           JS::Handle<JSObject*> origObj,
+                                           JS::Handle<JSObject*> target);
+
+bool IsUAWidgetCompartment(JS::Compartment* compartment);
+bool IsUAWidgetScope(JS::Realm* realm);
+bool IsInUAWidgetScope(JSObject* obj);
+
+bool MightBeWebContentCompartment(JS::Compartment* compartment);
+
+void SetCompartmentChangedDocumentDomain(JS::Compartment* compartment);
+
+JSObject* GetUAWidgetScope(JSContext* cx, nsIPrincipal* principal);
+
+JSObject* GetUAWidgetScope(JSContext* cx, JSObject* contentScope);
+
+// Returns whether XBL scopes have been explicitly disabled for code running
+// in this compartment. See the comment around mAllowContentXBLScope.
+bool AllowContentXBLScope(JS::Realm* realm);
+
+// Get the scope for creating reflectors for native anonymous content
+// whose normal global would be the given global.
+JSObject* NACScope(JSObject* global);
+
+bool IsSandboxPrototypeProxy(JSObject* obj);
+bool IsWebExtensionContentScriptSandbox(JSObject* obj);
+
+// The JSContext argument represents the Realm that's asking the question.  This
+// is needed to properly answer without exposing information unnecessarily
+// from behind security wrappers.  There will be no exceptions thrown on this
+// JSContext.
+bool IsReflector(JSObject* obj, JSContext* cx);
+
+bool IsXrayWrapper(JSObject* obj);
+
+// If this function was created for a given XrayWrapper, returns the global of
+// the Xrayed object. Otherwise, returns the global of the function.
+//
+// To emphasize the obvious: the return value here is not necessarily same-
+// compartment with the argument.
+JSObject* XrayAwareCalleeGlobal(JSObject* fun);
+
+void TraceXPCGlobal(JSTracer* trc, JSObject* obj);
+
+/**
+ * Creates a new global object using the given aCOMObj as the global
+ * object. The object will be set up according to the flags (defined
+ * below). If you do not pass INIT_JS_STANDARD_CLASSES, then aCOMObj
+ * must implement nsIXPCScriptable so it can resolve the standard
+ * classes when asked by the JS engine.
+ *
+ * @param aJSContext the context to use while creating the global object.
+ * @param aCOMObj the native object that represents the global object.
+ * @param aPrincipal the principal of the code that will run in this
+ *                   compartment. Can be null if not on the main thread.
+ * @param aFlags one of the flags below specifying what options this
+ *               global object wants.
+ * @param aOptions JSAPI-specific options for the new compartment.
+ */
+nsresult InitClassesWithNewWrappedGlobal(
+    JSContext* aJSContext, nsISupports* aCOMObj, nsIPrincipal* aPrincipal,
+    uint32_t aFlags, JS::RealmOptions& aOptions,
+    JS::MutableHandle<JSObject*> aNewGlobal);
+
+enum InitClassesFlag {
+  INIT_JS_STANDARD_CLASSES = 1 << 0,
+  DONT_FIRE_ONNEWGLOBALHOOK = 1 << 1,
+  OMIT_COMPONENTS_OBJECT = 1 << 2,
+};
+
+} /* namespace xpc */
+
+namespace JS {
+
+struct RuntimeStats;
+
+}  // namespace JS
+
+static_assert(JSCLASS_GLOBAL_APPLICATION_SLOTS > 0,
+              "Need at least one slot for JSCLASS_SLOT0_IS_NSISUPPORTS");
+
+#define XPCONNECT_GLOBAL_FLAGS_WITH_EXTRA_SLOTS(n)    \
+  JSCLASS_DOM_GLOBAL | JSCLASS_SLOT0_IS_NSISUPPORTS | \
+      JSCLASS_GLOBAL_FLAGS_WITH_SLOTS(DOM_GLOBAL_SLOTS + n)
+
+#define XPCONNECT_GLOBAL_EXTRA_SLOT_OFFSET \
+  (JSCLASS_GLOBAL_SLOT_COUNT + DOM_GLOBAL_SLOTS)
+
+#define XPCONNECT_GLOBAL_FLAGS XPCONNECT_GLOBAL_FLAGS_WITH_EXTRA_SLOTS(0)
+
+inline JSObject* xpc_FastGetCachedWrapper(JSContext* cx, nsWrapperCache* cache,
+                                          JS::MutableHandle<JS::Value> vp) {
+  if (cache) {
+    JSObject* wrapper = cache->GetWrapper();
+    if (wrapper &&
+        JS::GetCompartment(wrapper) == js::GetContextCompartment(cx)) {
+      vp.setObject(*wrapper);
+      return wrapper;
+    }
+  }
+
+  return nullptr;
+}
+
+// If aWrappedJS is a JS wrapper, unmark its JSObject.
+extern void xpc_TryUnmarkWrappedGrayObject(nsISupports* aWrappedJS);
+
+extern void xpc_UnmarkSkippableJSHolders();
+
+// Defined in XPCDebug.cpp.
+extern bool xpc_DumpJSStack(bool showArgs, bool showLocals, bool showThisProps);
+
+// Return a newly-allocated string containing a representation of the
+// current JS stack. Defined in XPCDebug.cpp.
+extern JS::UniqueChars xpc_PrintJSStack(JSContext* cx, bool showArgs,
+                                        bool showLocals, bool showThisProps);
+
+// readable string conversions, static methods and members only
+class XPCStringConvert {
+ public:
+  // If the string shares the readable's buffer, that buffer will
+  // get assigned to *sharedBuffer.  Otherwise null will be
+  // assigned.
+  static bool ReadableToJSVal(JSContext* cx, const nsAString& readable,
+                              nsStringBuffer** sharedBuffer,
+                              JS::MutableHandle<JS::Value> vp);
+
+  // Convert the given stringbuffer/length pair to a jsval
+  static MOZ_ALWAYS_INLINE bool StringBufferToJSVal(
+      JSContext* cx, nsStringBuffer* buf, uint32_t length,
+      JS::MutableHandle<JS::Value> rval, bool* sharedBuffer) {
+    JSString* str = JS_NewMaybeExternalString(
+        cx, static_cast<char16_t*>(buf->Data()), length,
+        &sDOMStringExternalString, sharedBuffer);
+    if (!str) {
+      return false;
+    }
+    rval.setString(str);
+    return true;
+  }
+
+  static inline bool StringLiteralToJSVal(JSContext* cx,
+                                          const char16_t* literal,
+                                          uint32_t length,
+                                          JS::MutableHandle<JS::Value> rval) {
+    bool ignored;
+    JSString* str = JS_NewMaybeExternalString(
+        cx, literal, length, &sLiteralExternalString, &ignored);
+    if (!str) {
+      return false;
+    }
+    rval.setString(str);
+    return true;
+  }
+
+  static inline bool DynamicAtomToJSVal(JSContext* cx, nsDynamicAtom* atom,
+                                        JS::MutableHandle<JS::Value> rval) {
+    bool sharedAtom;
+    JSString* str =
+        JS_NewMaybeExternalString(cx, atom->GetUTF16String(), atom->GetLength(),
+                                  &sDynamicAtomExternalString, &sharedAtom);
+    if (!str) {
+      return false;
+    }
+    if (sharedAtom) {
+      // We only have non-owning atoms in DOMString for now.
+      // nsDynamicAtom::AddRef is always-inline and defined in a
+      // translation unit we can't get to here.  So we need to go through
+      // nsAtom::AddRef to call it.
+      static_cast<nsAtom*>(atom)->AddRef();
+    }
+    rval.setString(str);
+    return true;
+  }
+
+  static MOZ_ALWAYS_INLINE bool MaybeGetExternalStringChars(
+      JSString* str, const JSExternalStringCallbacks* desiredCallbacks,
+      const char16_t** chars) {
+    const JSExternalStringCallbacks* callbacks;
+    return JS::IsExternalString(str, &callbacks, chars) &&
+           callbacks == desiredCallbacks;
+  }
+
+  // Returns non-null chars if the given string is a literal external string.
+  static MOZ_ALWAYS_INLINE bool MaybeGetLiteralStringChars(
+      JSString* str, const char16_t** chars) {
+    return MaybeGetExternalStringChars(str, &sLiteralExternalString, chars);
+  }
+
+  // Returns non-null chars if the given string is a DOM external string.
+  static MOZ_ALWAYS_INLINE bool MaybeGetDOMStringChars(JSString* str,
+                                                       const char16_t** chars) {
+    return MaybeGetExternalStringChars(str, &sDOMStringExternalString, chars);
+  }
+
+ private:
+  struct LiteralExternalString : public JSExternalStringCallbacks {
+    void finalize(char16_t* aChars) const override;
+    size_t sizeOfBuffer(const char16_t* aChars,
+                        mozilla::MallocSizeOf aMallocSizeOf) const override;
+  };
+  struct DOMStringExternalString : public JSExternalStringCallbacks {
+    void finalize(char16_t* aChars) const override;
+    size_t sizeOfBuffer(const char16_t* aChars,
+                        mozilla::MallocSizeOf aMallocSizeOf) const override;
+  };
+  struct DynamicAtomExternalString : public JSExternalStringCallbacks {
+    void finalize(char16_t* aChars) const override;
+    size_t sizeOfBuffer(const char16_t* aChars,
+                        mozilla::MallocSizeOf aMallocSizeOf) const override;
+  };
+  static const LiteralExternalString sLiteralExternalString;
+  static const DOMStringExternalString sDOMStringExternalString;
+  static const DynamicAtomExternalString sDynamicAtomExternalString;
+
+  XPCStringConvert() = delete;
+};
+
+namespace xpc {
+
+// If these functions return false, then an exception will be set on cx.
+bool Base64Encode(JSContext* cx, JS::Handle<JS::Value> val,
+                  JS::MutableHandle<JS::Value> out);
+bool Base64Decode(JSContext* cx, JS::Handle<JS::Value> val,
+                  JS::MutableHandle<JS::Value> out);
+
+/**
+ * Convert an nsString to jsval, returning true on success.
+ * Note, the ownership of the string buffer may be moved from str to rval.
+ * If that happens, str will point to an empty string after this call.
+ */
+bool NonVoidStringToJsval(JSContext* cx, nsAString& str,
+                          JS::MutableHandle<JS::Value> rval);
+inline bool StringToJsval(JSContext* cx, nsAString& str,
+                          JS::MutableHandle<JS::Value> rval) {
+  // From the T_ASTRING case in XPCConvert::NativeData2JS.
+  if (str.IsVoid()) {
+    rval.setNull();
+    return true;
+  }
+  return NonVoidStringToJsval(cx, str, rval);
+}
+
+inline bool NonVoidStringToJsval(JSContext* cx, const nsAString& str,
+                                 JS::MutableHandle<JS::Value> rval) {
+  nsString mutableCopy;
+  if (!mutableCopy.Assign(str, mozilla::fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return false;
+  }
+  return NonVoidStringToJsval(cx, mutableCopy, rval);
+}
+
+inline bool StringToJsval(JSContext* cx, const nsAString& str,
+                          JS::MutableHandle<JS::Value> rval) {
+  nsString mutableCopy;
+  if (!mutableCopy.Assign(str, mozilla::fallible)) {
+    JS_ReportOutOfMemory(cx);
+    return false;
+  }
+  return StringToJsval(cx, mutableCopy, rval);
+}
+
+/**
+ * As above, but for mozilla::dom::DOMString.
+ */
+inline bool NonVoidStringToJsval(JSContext* cx, mozilla::dom::DOMString& str,
+                                 JS::MutableHandle<JS::Value> rval) {
+  if (str.IsEmpty()) {
+    rval.set(JS_GetEmptyStringValue(cx));
+    return true;
+  }
+
+  if (str.HasStringBuffer()) {
+    uint32_t length = str.StringBufferLength();
+    nsStringBuffer* buf = str.StringBuffer();
+    bool shared;
+    if (!XPCStringConvert::StringBufferToJSVal(cx, buf, length, rval,
+                                               &shared)) {
+      return false;
+    }
+    if (shared) {
+      // JS now needs to hold a reference to the buffer
+      str.RelinquishBufferOwnership();
+    }
+    return true;
+  }
+
+  if (str.HasLiteral()) {
+    return XPCStringConvert::StringLiteralToJSVal(cx, str.Literal(),
+                                                  str.LiteralLength(), rval);
+  }
+
+  if (str.HasAtom()) {
+    return XPCStringConvert::DynamicAtomToJSVal(cx, str.Atom(), rval);
+  }
+
+  // It's an actual XPCOM string
+  return NonVoidStringToJsval(cx, str.AsAString(), rval);
+}
+
+MOZ_ALWAYS_INLINE
+bool StringToJsval(JSContext* cx, mozilla::dom::DOMString& str,
+                   JS::MutableHandle<JS::Value> rval) {
+  if (str.IsNull()) {
+    rval.setNull();
+    return true;
+  }
+  return NonVoidStringToJsval(cx, str, rval);
+}
+
+mozilla::BasePrincipal* GetRealmPrincipal(JS::Realm* realm);
+
+void NukeAllWrappersForRealm(JSContext* cx, JS::Realm* realm,
+                             js::NukeReferencesToWindow nukeReferencesToWindow =
+                                 js::NukeWindowReferences);
+
+void SetLocationForGlobal(JSObject* global, const nsACString& location);
+void SetLocationForGlobal(JSObject* global, nsIURI* locationURI);
+
+// ReportJSRuntimeExplicitTreeStats will expect this in the |extra| member
+// of JS::ZoneStats.
+class ZoneStatsExtras {
+ public:
+  ZoneStatsExtras() = default;
+
+  nsCString pathPrefix;
+
+ private:
+  ZoneStatsExtras(const ZoneStatsExtras& other) = delete;
+  ZoneStatsExtras& operator=(const ZoneStatsExtras& other) = delete;
+};
+
+// ReportJSRuntimeExplicitTreeStats will expect this in the |extra| member
+// of JS::RealmStats.
+class RealmStatsExtras {
+ public:
+  RealmStatsExtras() = default;
+
+  nsCString jsPathPrefix;
+  nsCString domPathPrefix;
+  nsCOMPtr<nsIURI> location;
+
+ private:
+  RealmStatsExtras(const RealmStatsExtras& other) = delete;
+  RealmStatsExtras& operator=(const RealmStatsExtras& other) = delete;
+};
+
+// This reports all the stats in |rtStats| that belong in the "explicit" tree,
+// (which isn't all of them).
+// @see ZoneStatsExtras
+// @see RealmStatsExtras
+void ReportJSRuntimeExplicitTreeStats(const JS::RuntimeStats& rtStats,
+                                      const nsACString& rtPath,
+                                      nsIHandleReportCallback* handleReport,
+                                      nsISupports* data, bool anonymize,
+                                      size_t* rtTotal = nullptr);
+
+/**
+ * Throws an exception on cx and returns false.
+ */
+bool Throw(JSContext* cx, nsresult rv);
+
+/**
+ * Returns the nsISupports native behind a given reflector (either DOM or
+ * XPCWN).  If a non-reflector object is passed in, null will be returned.
+ *
+ * This function will not correctly handle Window or Location objects behind
+ * cross-compartment wrappers: it will return null.  If you care about getting
+ * non-null for Window or Location, use ReflectorToISupportsDynamic.
+ */
+already_AddRefed<nsISupports> ReflectorToISupportsStatic(JSObject* reflector);
+
+/**
+ * Returns the nsISupports native behind a given reflector (either DOM or
+ * XPCWN).  If a non-reflector object is passed in, null will be returned.
+ *
+ * The JSContext argument represents the Realm that's asking for the
+ * nsISupports.  This is needed to properly handle Window and Location objects,
+ * which do dynamic security checks.
+ */
+already_AddRefed<nsISupports> ReflectorToISupportsDynamic(JSObject* reflector,
+                                                          JSContext* cx);
+
+/**
+ * Singleton scopes for stuff that really doesn't fit anywhere else.
+ *
+ * If you find yourself wanting to use these compartments, you're probably doing
+ * something wrong. Callers MUST consult with the XPConnect module owner before
+ * using this compartment. If you don't, bholley will hunt you down.
+ */
+JSObject* UnprivilegedJunkScope();
+
+JSObject* UnprivilegedJunkScope(const mozilla::fallible_t&);
+
+bool IsUnprivilegedJunkScope(JSObject*);
+
+/**
+ * This will generally be the shared JSM global, but callers should not depend
+ * on that fact.
+ */
+JSObject* PrivilegedJunkScope();
+
+/**
+ * Shared compilation scope for XUL prototype documents and XBL
+ * precompilation.
+ */
+JSObject* CompilationScope();
+
+/**
+ * Returns the nsIGlobalObject corresponding to |obj|'s JS global. |obj| must
+ * not be a cross-compartment wrapper: CCWs are not associated with a single
+ * global.
+ */
+nsIGlobalObject* NativeGlobal(JSObject* obj);
+
+/**
+ * Returns the nsIGlobalObject corresponding to |cx|'s JS global. Must not be
+ * called when |cx| is not in a Realm.
+ */
+nsIGlobalObject* CurrentNativeGlobal(JSContext* cx);
+
+/**
+ * If |aObj| is a window, returns the associated nsGlobalWindow.
+ * Otherwise, returns null.
+ */
+nsGlobalWindowInner* WindowOrNull(JSObject* aObj);
+
+/**
+ * If |aObj| has a window for a global, returns the associated nsGlobalWindow.
+ * Otherwise, returns null. Note: aObj must not be a cross-compartment wrapper
+ * because CCWs are not associated with a single global/realm.
+ */
+nsGlobalWindowInner* WindowGlobalOrNull(JSObject* aObj);
+
+/**
+ * If |aObj| is a Sandbox object associated with a DOMWindow via a
+ * sandboxPrototype, then return that DOMWindow.
+ * |aCx| is used for checked unwrapping of the Window.
+ */
+nsGlobalWindowInner* SandboxWindowOrNull(JSObject* aObj, JSContext* aCx);
+
+/**
+ * If |cx| is in a realm whose global is a window, returns the associated
+ * nsGlobalWindow. Otherwise, returns null.
+ */
+nsGlobalWindowInner* CurrentWindowOrNull(JSContext* cx);
+
+class MOZ_RAII AutoScriptActivity {
+  bool mActive;
+  bool mOldValue;
+
+ public:
+  explicit AutoScriptActivity(bool aActive);
+  ~AutoScriptActivity();
+};
+
+// This function may be used off-main-thread, in which case it is benignly
+// racey.
+bool ShouldDiscardSystemSource();
+
+void SetPrefableRealmOptions(JS::RealmOptions& options);
+void SetPrefableContextOptions(JS::ContextOptions& options);
+
+class ErrorBase {
+ public:
+  nsString mErrorMsg;
+  nsString mFileName;
+  uint32_t mSourceId;
+  uint32_t mLineNumber;
+  uint32_t mColumn;
+
+  ErrorBase() : mSourceId(0), mLineNumber(0), mColumn(0) {}
+
+  void Init(JSErrorBase* aReport);
+
+  void AppendErrorDetailsTo(nsCString& error);
+};
+
+class ErrorNote : public ErrorBase {
+ public:
+  void Init(JSErrorNotes::Note* aNote);
+
+  // Produce an error event message string from the given JSErrorNotes::Note.
+  // This may produce an empty string if aNote doesn't have a message
+  // attached.
+  static void ErrorNoteToMessageString(JSErrorNotes::Note* aNote,
+                                       nsAString& aString);
+
+  // Log the error note to the stderr.
+  void LogToStderr();
+};
+
+class ErrorReport : public ErrorBase {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ErrorReport);
+
+  nsTArray<ErrorNote> mNotes;
+
+  nsCString mCategory;
+  nsString mSourceLine;
+  nsString mErrorMsgName;
+  uint64_t mWindowID;
+  bool mIsWarning;
+  bool mIsMuted;
+  bool mIsPromiseRejection;
+
+  ErrorReport()
+      : mWindowID(0),
+        mIsWarning(false),
+        mIsMuted(false),
+        mIsPromiseRejection(false) {}
+
+  void Init(JSErrorReport* aReport, const char* aToStringResult, bool aIsChrome,
+            uint64_t aWindowID);
+  void Init(JSContext* aCx, mozilla::dom::Exception* aException, bool aIsChrome,
+            uint64_t aWindowID);
+
+  // Log the error report to the console.  Which console will depend on the
+  // window id it was initialized with.
+  void LogToConsole();
+  // Log to console, using the given stack object (which should be a stack of
+  // the sort that JS::CaptureCurrentStack produces).  aStack is allowed to be
+  // null. If aStack is non-null, aStackGlobal must be a non-null global
+  // object that's same-compartment with aStack. Note that aStack might be a
+  // CCW.
+  void LogToConsoleWithStack(nsGlobalWindowInner* aWin,
+                             JS::Handle<mozilla::Maybe<JS::Value>> aException,
+                             JS::Handle<JSObject*> aStack,
+                             JS::Handle<JSObject*> aStackGlobal);
+
+  // Produce an error event message string from the given JSErrorReport.  Note
+  // that this may produce an empty string if aReport doesn't have a
+  // message attached.
+  static void ErrorReportToMessageString(JSErrorReport* aReport,
+                                         nsAString& aString);
+
+  // Log the error report to the stderr.
+  void LogToStderr();
+
+  bool IsWarning() const { return mIsWarning; };
+
+ private:
+  ~ErrorReport() = default;
+};
+
+void DispatchScriptErrorEvent(nsPIDOMWindowInner* win,
+                              JS::RootingContext* rootingCx,
+                              xpc::ErrorReport* xpcReport,
+                              JS::Handle<JS::Value> exception,
+                              JS::Handle<JSObject*> exceptionStack);
+
+// Get a stack (as stackObj outparam) of the sort that can be passed to
+// xpc::ErrorReport::LogToConsoleWithStack from the given exception value.  Can
+// be nullptr if the exception value doesn't have an associated stack, and if
+// there is no stack supplied by the JS engine in exceptionStack.  The
+// returned stack, if any, may also not be in the same compartment as
+// exceptionValue.
+//
+// The "win" argument passed in here should be the same as the window whose
+// WindowID() is used to initialize the xpc::ErrorReport.  This may be null, of
+// course.  If it's not null, this function may return a null stack object if
+// the window is far enough gone, because in those cases we don't want to have
+// the stack in the console message keeping the window alive.
+//
+// If this function sets stackObj to a non-null value, stackGlobal is set to
+// either the JS exception object's global or the global of the SavedFrame we
+// got from a DOM or XPConnect exception. In all cases, stackGlobal is an
+// unwrapped global object and is same-compartment with stackObj.
+void FindExceptionStackForConsoleReport(
+    nsPIDOMWindowInner* win, JS::Handle<JS::Value> exceptionValue,
+    JS::Handle<JSObject*> exceptionStack, JS::MutableHandle<JSObject*> stackObj,
+    JS::MutableHandle<JSObject*> stackGlobal);
+
+// Return a name for the realm.
+// This function makes reasonable efforts to make this name both mostly
+// human-readable and unique. However, there are no guarantees of either
+// property.
+extern void GetCurrentRealmName(JSContext*, nsCString& name);
+
+nsCString GetFunctionName(JSContext* cx, JS::Handle<JSObject*> obj);
+
+void AddGCCallback(xpcGCCallback cb);
+void RemoveGCCallback(xpcGCCallback cb);
+
+// We need an exact page size only if we run the binary in automation.
+#if defined(XP_DARWIN) && defined(__aarch64__)
+const size_t kAutomationPageSize = 16384;
+#else
+const size_t kAutomationPageSize = 4096;
+#endif
+
+struct alignas(kAutomationPageSize) ReadOnlyPage final {
+  bool mNonLocalConnectionsDisabled = false;
+  bool mTurnOffAllSecurityPref = false;
+
+  static void Init();
+
+#ifdef MOZ_TSAN
+  // TSan is confused by write access to read-only section.
+  static ReadOnlyPage sInstance;
+#else
+  static const volatile ReadOnlyPage sInstance;
+#endif
+
+ private:
+  constexpr ReadOnlyPage() = default;
+  ReadOnlyPage(const ReadOnlyPage&) = delete;
+  void operator=(const ReadOnlyPage&) = delete;
+
+  static void Write(const volatile bool* aPtr, bool aValue);
+};
+
+inline bool AreNonLocalConnectionsDisabled() {
+  return ReadOnlyPage::sInstance.mNonLocalConnectionsDisabled;
+}
+
+inline bool IsInAutomation() {
+  if (!ReadOnlyPage::sInstance.mTurnOffAllSecurityPref) {
+    return false;
+  }
+  MOZ_RELEASE_ASSERT(AreNonLocalConnectionsDisabled());
+  return true;
+}
+
+void InitializeJSContext();
+
+/**
+ * Extract the native nsID object from a JS ID, IfaceID, ClassID, or ContractID
+ * value.
+ *
+ * Returns 'Nothing()' if 'aVal' does is not one of the supported ID types.
+ */
+mozilla::Maybe<nsID> JSValue2ID(JSContext* aCx, JS::Handle<JS::Value> aVal);
+
+/**
+ * Reflect an ID into JS
+ */
+bool ID2JSValue(JSContext* aCx, const nsID& aId,
+                JS::MutableHandle<JS::Value> aVal);
+
+/**
+ * Reflect an IfaceID into JS
+ *
+ * This object will expose constants from the selected interface, and support
+ * 'instanceof', in addition to the other methods available on JS ID objects.
+ *
+ * Use 'xpc::JSValue2ID' to unwrap JS::Values created with this function.
+ */
+bool IfaceID2JSValue(JSContext* aCx, const nsXPTInterfaceInfo& aInfo,
+                     JS::MutableHandle<JS::Value> aVal);
+
+/**
+ * Reflect a ContractID into JS
+ *
+ * This object will expose 'getService' and 'createInstance' methods in addition
+ * to the other methods available on nsID objects.
+ *
+ * Use 'xpc::JSValue2ID' to unwrap JS::Values created with this function.
+ */
+bool ContractID2JSValue(JSContext* aCx, JSString* aContract,
+                        JS::MutableHandle<JS::Value> 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);
+
+// Check whether the given jsid is a property name (string or symbol) whose
+// value can be gotten cross-origin.  Cross-origin gets always return undefined
+// as the value, unless the Xray actually provides a different value.
+bool IsCrossOriginWhitelistedProp(JSContext* cx,
+                                  JS::Handle<JS::PropertyKey> id);
+
+// Appends to props the jsids for property names (strings or symbols) whose
+// value can be gotten cross-origin.
+bool AppendCrossOriginWhitelistedPropNames(
+    JSContext* cx, JS::MutableHandle<JS::StackGCVector<JS::PropertyKey>> props);
+}  // namespace xpc
+
+namespace mozilla {
+namespace dom {
+
+/**
+ * This is used to prevent UA widget code from directly creating and adopting
+ * nodes via the content document, since they should use the special
+ * create-and-insert apis instead.
+ */
+bool IsNotUAWidget(JSContext* cx, JSObject* /* unused */);
+
+/**
+ * A test for whether WebIDL methods that should only be visible to
+ * chrome, XBL scopes, or UA Widget scopes.
+ */
+bool IsChromeOrUAWidget(JSContext* cx, JSObject* /* unused */);
+
+/**
+ * Same as IsChromeOrUAWidget but can be used in worker threads as well.
+ */
+bool ThreadSafeIsChromeOrUAWidget(JSContext* cx, JSObject* obj);
+
+}  // namespace dom
+
+/**
+ * Fill the given vector with the buildid.
+ */
+bool GetBuildId(JS::BuildIdCharVector* aBuildID);
+
+}  // namespace mozilla
+
+#endif