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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 01:47:29 +0000
commit0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch)
treea31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /dom/bindings/ToJSValue.h
parentInitial commit. (diff)
downloadfirefox-esr-upstream/115.8.0esr.tar.xz
firefox-esr-upstream/115.8.0esr.zip
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'dom/bindings/ToJSValue.h')
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1 files changed, 486 insertions, 0 deletions
diff --git a/dom/bindings/ToJSValue.h b/dom/bindings/ToJSValue.h
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+/* -*- 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 mozilla_dom_ToJSValue_h
+#define mozilla_dom_ToJSValue_h
+
+#include <cstddef> // for size_t
+#include <cstdint> // for int32_t, int64_t, uint32_t, uint64_t
+#include <type_traits> // for is_base_of, enable_if_t, enable_if, is_pointer, is_same, void_t
+#include <utility> // for forward
+#include "ErrorList.h" // for nsresult
+#include "js/Array.h" // for NewArrayObject
+#include "js/GCVector.h" // for RootedVector, MutableWrappedPtrOperations
+#include "js/PropertyAndElement.h" // JS_DefineUCProperty
+#include "js/RootingAPI.h" // for MutableHandle, Rooted, Handle, Heap
+#include "js/Value.h" // for Value
+#include "js/ValueArray.h" // for HandleValueArray
+#include "jsapi.h" // for CurrentGlobalOrNull
+#include "mozilla/Assertions.h" // for AssertionConditionType, MOZ_ASSERT, MOZ_ASSERT_HELPER1
+#include "mozilla/UniquePtr.h" // for UniquePtr
+#include "mozilla/Unused.h" // for Unused
+#include "mozilla/dom/BindingUtils.h" // for MaybeWrapValue, MaybeWrapObjectOrNullValue, XPCOMObjectToJsval, GetOrCreateDOMReflector
+#include "mozilla/dom/CallbackObject.h" // for CallbackObject
+#include "mozilla/dom/Record.h"
+#include "nsID.h" // for NS_GET_TEMPLATE_IID, nsIID
+#include "nsISupports.h" // for nsISupports
+#include "nsStringFwd.h" // for nsAString
+#include "nsTArrayForwardDeclare.h"
+#include "xpcObjectHelper.h" // for xpcObjectHelper
+
+namespace mozilla::dom {
+
+class CallbackObject;
+class Promise;
+class WindowProxyHolder;
+template <typename TypedArrayType>
+class TypedArrayCreator;
+
+// If ToJSValue returns false, it must set an exception on the
+// JSContext.
+
+// Accept strings.
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const nsAString& aArgument,
+ JS::MutableHandle<JS::Value> aValue);
+
+// Treats the input as UTF-8, and throws otherwise.
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const nsACString& aArgument,
+ JS::MutableHandle<JS::Value> aValue);
+
+// Accept booleans. But be careful here: if we just have a function that takes
+// a boolean argument, then any pointer that doesn't match one of our other
+// signatures/templates will get treated as a boolean, which is clearly not
+// desirable. So make this a template that only gets used if the argument type
+// is actually boolean
+template <typename T>
+[[nodiscard]] std::enable_if_t<std::is_same<T, bool>::value, bool> ToJSValue(
+ JSContext* aCx, T aArgument, JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setBoolean(aArgument);
+ return true;
+}
+
+// Accept integer types
+inline bool ToJSValue(JSContext* aCx, int32_t aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setInt32(aArgument);
+ return true;
+}
+
+inline bool ToJSValue(JSContext* aCx, uint32_t aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setNumber(aArgument);
+ return true;
+}
+
+inline bool ToJSValue(JSContext* aCx, int64_t aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setNumber(double(aArgument));
+ return true;
+}
+
+inline bool ToJSValue(JSContext* aCx, uint64_t aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setNumber(double(aArgument));
+ return true;
+}
+
+// accept floating point types
+inline bool ToJSValue(JSContext* aCx, float aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setNumber(aArgument);
+ return true;
+}
+
+inline bool ToJSValue(JSContext* aCx, double aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.set(JS_NumberValue(aArgument));
+ return true;
+}
+
+// Accept CallbackObjects
+[[nodiscard]] inline bool ToJSValue(JSContext* aCx, CallbackObject& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ aValue.setObjectOrNull(aArgument.Callback(aCx));
+
+ return MaybeWrapValue(aCx, aValue);
+}
+
+// Accept objects that inherit from nsWrapperCache (e.g. most
+// DOM objects).
+template <class T>
+[[nodiscard]] std::enable_if_t<std::is_base_of<nsWrapperCache, T>::value, bool>
+ToJSValue(JSContext* aCx, T& aArgument, JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ return GetOrCreateDOMReflector(aCx, aArgument, aValue);
+}
+
+// Accept non-refcounted DOM objects that do not inherit from
+// nsWrapperCache. Refcounted ones would be too much of a footgun:
+// you could convert them to JS twice and get two different objects.
+namespace binding_detail {
+template <class T>
+[[nodiscard]] std::enable_if_t<
+ std::is_base_of<NonRefcountedDOMObject, T>::value, bool>
+ToJSValueFromPointerHelper(JSContext* aCx, T* aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ // This is a cut-down version of
+ // WrapNewBindingNonWrapperCachedObject that doesn't need to deal
+ // with nearly as many cases.
+ if (!aArgument) {
+ aValue.setNull();
+ return true;
+ }
+
+ JS::Rooted<JSObject*> obj(aCx);
+ if (!aArgument->WrapObject(aCx, nullptr, &obj)) {
+ return false;
+ }
+
+ aValue.setObject(*obj);
+ return true;
+}
+} // namespace binding_detail
+
+// We can take a non-refcounted non-wrapper-cached DOM object that lives in a
+// UniquePtr.
+template <class T>
+[[nodiscard]] std::enable_if_t<
+ std::is_base_of<NonRefcountedDOMObject, T>::value, bool>
+ToJSValue(JSContext* aCx, UniquePtr<T>&& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ if (!binding_detail::ToJSValueFromPointerHelper(aCx, aArgument.get(),
+ aValue)) {
+ return false;
+ }
+
+ // JS object took ownership
+ Unused << aArgument.release();
+ return true;
+}
+
+// Accept typed arrays built from appropriate nsTArray values
+template <typename T>
+[[nodiscard]]
+typename std::enable_if<std::is_base_of<AllTypedArraysBase, T>::value,
+ bool>::type
+ToJSValue(JSContext* aCx, const TypedArrayCreator<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ JSObject* obj = aArgument.Create(aCx);
+ if (!obj) {
+ return false;
+ }
+ aValue.setObject(*obj);
+ return true;
+}
+
+namespace binding_detail {
+// Helper type alias for picking a script-exposable non-wrappercached XPIDL
+// interface to expose to JS code. Falls back to `nsISupports` if the specific
+// interface type is ambiguous.
+template <typename T, typename = void>
+struct GetScriptableInterfaceType {
+ using Type = nsISupports;
+
+ static_assert(std::is_base_of_v<nsISupports, T>,
+ "T must inherit from nsISupports");
+};
+template <typename T>
+struct GetScriptableInterfaceType<
+ T, std::void_t<typename T::ScriptableInterfaceType>> {
+ using Type = typename T::ScriptableInterfaceType;
+
+ static_assert(std::is_base_of_v<Type, T>,
+ "T must inherit from ScriptableInterfaceType");
+ static_assert(std::is_base_of_v<nsISupports, Type>,
+ "ScriptableInterfaceType must inherit from nsISupports");
+};
+
+template <typename T>
+using ScriptableInterfaceType = typename GetScriptableInterfaceType<T>::Type;
+} // namespace binding_detail
+
+// Accept objects that inherit from nsISupports but not nsWrapperCache (e.g.
+// DOM File).
+template <class T>
+[[nodiscard]] std::enable_if_t<!std::is_base_of<nsWrapperCache, T>::value &&
+ !std::is_base_of<CallbackObject, T>::value &&
+ std::is_base_of<nsISupports, T>::value,
+ bool>
+ToJSValue(JSContext* aCx, T& aArgument, JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ xpcObjectHelper helper(ToSupports(&aArgument));
+ JS::Rooted<JSObject*> scope(aCx, JS::CurrentGlobalOrNull(aCx));
+ const nsIID& iid =
+ NS_GET_TEMPLATE_IID(binding_detail::ScriptableInterfaceType<T>);
+ return XPCOMObjectToJsval(aCx, scope, helper, &iid, true, aValue);
+}
+
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const WindowProxyHolder& aArgument,
+ JS::MutableHandle<JS::Value> aValue);
+
+// Accept nsRefPtr/nsCOMPtr
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const nsCOMPtr<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, *aArgument.get(), aValue);
+}
+
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const RefPtr<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, *aArgument.get(), aValue);
+}
+
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const NonNull<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, *aArgument.get(), aValue);
+}
+
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const OwningNonNull<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, *aArgument.get(), aValue);
+}
+
+// Accept WebIDL dictionaries
+template <class T>
+[[nodiscard]] std::enable_if_t<std::is_base_of<DictionaryBase, T>::value, bool>
+ToJSValue(JSContext* aCx, const T& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return aArgument.ToObjectInternal(aCx, aValue);
+}
+
+// Accept existing JS values (which may not be same-compartment with us
+[[nodiscard]] inline bool ToJSValue(JSContext* aCx, const JS::Value& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ aValue.set(aArgument);
+ return MaybeWrapValue(aCx, aValue);
+}
+[[nodiscard]] inline bool ToJSValue(JSContext* aCx,
+ JS::Handle<JS::Value> aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ aValue.set(aArgument);
+ return MaybeWrapValue(aCx, aValue);
+}
+
+// Accept existing JS values on the Heap (which may not be same-compartment with
+// us
+[[nodiscard]] inline bool ToJSValue(JSContext* aCx,
+ const JS::Heap<JS::Value>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ aValue.set(aArgument);
+ return MaybeWrapValue(aCx, aValue);
+}
+
+// Accept existing rooted JS values (which may not be same-compartment with us
+[[nodiscard]] inline bool ToJSValue(JSContext* aCx,
+ const JS::Rooted<JS::Value>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ aValue.set(aArgument);
+ return MaybeWrapValue(aCx, aValue);
+}
+
+// Accept existing rooted JS objects (which may not be same-compartment with
+// us).
+[[nodiscard]] inline bool ToJSValue(JSContext* aCx,
+ const JS::Rooted<JSObject*>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ aValue.setObjectOrNull(aArgument);
+ return MaybeWrapObjectOrNullValue(aCx, aValue);
+}
+
+// Accept nsresult, for use in rejections, and create an XPCOM
+// exception object representing that nsresult.
+[[nodiscard]] bool ToJSValue(JSContext* aCx, nsresult aArgument,
+ JS::MutableHandle<JS::Value> aValue);
+
+// Accept ErrorResult, for use in rejections, and create an exception
+// representing the failure. Note, the ErrorResult must indicate a failure
+// with aArgument.Failure() returning true.
+[[nodiscard]] bool ToJSValue(JSContext* aCx, ErrorResult&& aArgument,
+ JS::MutableHandle<JS::Value> aValue);
+
+// Accept owning WebIDL unions.
+template <typename T>
+[[nodiscard]] std::enable_if_t<std::is_base_of<AllOwningUnionBase, T>::value,
+ bool>
+ToJSValue(JSContext* aCx, const T& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ JS::Rooted<JSObject*> global(aCx, JS::CurrentGlobalOrNull(aCx));
+ return aArgument.ToJSVal(aCx, global, aValue);
+}
+
+// Accept pointers to other things we accept
+template <typename T>
+[[nodiscard]] std::enable_if_t<std::is_pointer<T>::value, bool> ToJSValue(
+ JSContext* aCx, T aArgument, JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, *aArgument, aValue);
+}
+
+// Accept Promise objects, which need special handling.
+[[nodiscard]] bool ToJSValue(JSContext* aCx, Promise& aArgument,
+ JS::MutableHandle<JS::Value> aValue);
+
+// Accept arrays (and nested arrays) of other things we accept
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, T* aArguments, size_t aLength,
+ JS::MutableHandle<JS::Value> aValue);
+
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const nsTArray<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, aArgument.Elements(), aArgument.Length(), aValue);
+}
+
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const FallibleTArray<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, aArgument.Elements(), aArgument.Length(), aValue);
+}
+
+template <typename T, int N>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const T (&aArgument)[N],
+ JS::MutableHandle<JS::Value> aValue) {
+ return ToJSValue(aCx, aArgument, N, aValue);
+}
+
+// Accept arrays of other things we accept
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, T* aArguments, size_t aLength,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ JS::RootedVector<JS::Value> v(aCx);
+ if (!v.resize(aLength)) {
+ return false;
+ }
+ for (size_t i = 0; i < aLength; ++i) {
+ if (!ToJSValue(aCx, aArguments[i], v[i])) {
+ return false;
+ }
+ }
+ JSObject* arrayObj = JS::NewArrayObject(aCx, v);
+ if (!arrayObj) {
+ return false;
+ }
+ aValue.setObject(*arrayObj);
+ return true;
+}
+
+// Accept tuple of other things we accept. The result will be a JS array object.
+template <typename... Elements>
+[[nodiscard]] bool ToJSValue(JSContext* aCx,
+ const std::tuple<Elements...>& aArguments,
+ JS::MutableHandle<JS::Value> aValue) {
+ // Make sure we're called in a compartment
+ MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
+
+ JS::RootedVector<JS::Value> v(aCx);
+ if (!v.resize(sizeof...(Elements))) {
+ return false;
+ }
+ bool ok = true;
+ size_t i = 0;
+ auto Callable = [aCx, &ok, &v, &i](auto& aElem) {
+ ok = ok && ToJSValue(aCx, aElem, v[i++]);
+ };
+ std::apply([Callable](auto&&... args) { (Callable(args), ...); }, aArguments);
+
+ if (!ok) {
+ return false;
+ }
+ JSObject* arrayObj = JS::NewArrayObject(aCx, v);
+ if (!arrayObj) {
+ return false;
+ }
+ aValue.setObject(*arrayObj);
+ return true;
+}
+
+// Accept records of other things we accept. N.B. This assumes that
+// keys are either UTF-8 or UTF-16-ish. See Bug 1706058.
+template <typename K, typename V>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const Record<K, V>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ JS::Rooted<JSObject*> recordObj(aCx, JS_NewPlainObject(aCx));
+ if (!recordObj) {
+ return false;
+ }
+
+ for (auto& entry : aArgument.Entries()) {
+ JS::Rooted<JS::Value> value(aCx);
+ if (!ToJSValue(aCx, entry.mValue, &value)) {
+ return false;
+ }
+
+ if constexpr (std::is_same_v<nsCString, decltype(entry.mKey)>) {
+ NS_ConvertUTF8toUTF16 expandedKey(entry.mKey);
+ if (!JS_DefineUCProperty(aCx, recordObj, expandedKey.BeginReading(),
+ expandedKey.Length(), value, JSPROP_ENUMERATE)) {
+ return false;
+ }
+ } else {
+ if (!JS_DefineUCProperty(aCx, recordObj, entry.mKey.BeginReading(),
+ entry.mKey.Length(), value, JSPROP_ENUMERATE)) {
+ return false;
+ }
+ }
+ }
+
+ aValue.setObject(*recordObj);
+ return true;
+}
+
+template <typename T>
+[[nodiscard]] bool ToJSValue(JSContext* aCx, const Nullable<T>& aArgument,
+ JS::MutableHandle<JS::Value> aValue) {
+ if (aArgument.IsNull()) {
+ aValue.setNull();
+ return true;
+ }
+
+ return ToJSValue(aCx, aArgument.Value(), aValue);
+}
+
+} // namespace mozilla::dom
+
+#endif /* mozilla_dom_ToJSValue_h */