Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 205 insertions, 0 deletions

diff --git a/js/src/vm/RealmFuses.cpp b/js/src/vm/RealmFuses.cpp
new file mode 100644
index 0000000000..3ceac2dd25
--- /dev/null
+++ b/js/src/vm/RealmFuses.cpp
@@ -0,0 +1,205 @@
+/* -*- 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 "vm/RealmFuses.h"
+
+#include "vm/GlobalObject.h"
+#include "vm/NativeObject.h"
+#include "vm/ObjectOperations.h"
+#include "vm/Realm.h"
+#include "vm/SelfHosting.h"
+
+void js::PopsOptimizedGetIteratorFuse::popFuse(JSContext* cx,
+                                               RealmFuses& realmFuses) {
+  // Pop Self.
+  RealmFuse::popFuse(cx);
+
+  // Pop associated fuse in same realm as current object.
+  realmFuses.optimizeGetIteratorFuse.popFuse(cx, realmFuses);
+}
+
+int32_t js::RealmFuses::fuseOffsets[uint8_t(
+    RealmFuses::FuseIndex::LastFuseIndex)] = {
+#define FUSE(Name, LowerName) offsetof(RealmFuses, LowerName),
+    FOR_EACH_REALM_FUSE(FUSE)
+#undef FUSE
+};
+
+// static
+int32_t js::RealmFuses::offsetOfFuseWordRelativeToRealm(
+    RealmFuses::FuseIndex index) {
+  int32_t base_offset = offsetof(Realm, realmFuses);
+  int32_t fuse_offset = RealmFuses::fuseOffsets[uint8_t(index)];
+  int32_t fuseWordOffset = GuardFuse::fuseOffset();
+
+  return base_offset + fuse_offset + fuseWordOffset;
+}
+
+const char* js::RealmFuses::fuseNames[] = {
+#define FUSE(Name, LowerName) #LowerName,
+    FOR_EACH_REALM_FUSE(FUSE)
+#undef FUSE
+};
+
+// TODO: It is not elegant that we have both this mechanism, but also
+// GuardFuse::name, and all the overrides for naming fuses. The issue is
+// that this method is static to handle consumers that don't have a
+// RealmFuses around but work with indexes (e.g. spew code).
+//
+// I'd love it if we had a better answer.
+const char* js::RealmFuses::getFuseName(RealmFuses::FuseIndex index) {
+  uint8_t rawIndex = uint8_t(index);
+  MOZ_ASSERT(rawIndex > 0 && index < RealmFuses::FuseIndex::LastFuseIndex);
+  return fuseNames[rawIndex];
+}
+
+bool js::OptimizeGetIteratorFuse::checkInvariant(JSContext* cx) {
+  // Simple invariant: this fuse merely reflects the conjunction of a group of
+  // fuses, so if this fuse is intact, then the invariant it asserts is that
+  // these two realm fuses are also intact.
+  auto& realmFuses = cx->realm()->realmFuses;
+  return realmFuses.arrayPrototypeIteratorFuse.intact() &&
+         realmFuses.arrayPrototypeIteratorNextFuse.intact() &&
+         realmFuses.arrayIteratorPrototypeHasNoReturnProperty.intact() &&
+         realmFuses.iteratorPrototypeHasNoReturnProperty.intact() &&
+         realmFuses.arrayIteratorPrototypeHasIteratorProto.intact() &&
+         realmFuses.iteratorPrototypeHasObjectProto.intact() &&
+         realmFuses.objectPrototypeHasNoReturnProperty.intact();
+}
+
+bool js::ArrayPrototypeIteratorFuse::checkInvariant(JSContext* cx) {
+  // Prototype must be Array.prototype.
+  auto* proto = cx->global()->maybeGetArrayPrototype();
+  if (!proto) {
+    // No proto, invariant still holds
+    return true;
+  }
+
+  PropertyKey iteratorKey =
+      PropertyKey::Symbol(cx->wellKnownSymbols().iterator);
+
+  // Ensure that Array.prototype's @@iterator slot is unchanged.
+  mozilla::Maybe<PropertyInfo> prop = proto->lookupPure(iteratorKey);
+  if (prop.isNothing() || !prop->isDataProperty()) {
+    return false;
+  }
+
+  auto slot = prop->slot();
+  const Value& iterVal = proto->getSlot(slot);
+  if (!iterVal.isObject() || !iterVal.toObject().is<JSFunction>()) {
+    return false;
+  }
+
+  auto* iterFun = &iterVal.toObject().as<JSFunction>();
+  return IsSelfHostedFunctionWithName(iterFun, cx->names().dollar_ArrayValues_);
+}
+
+/* static */
+bool js::ArrayPrototypeIteratorNextFuse::checkInvariant(JSContext* cx) {
+  auto* proto = cx->global()->maybeGetArrayIteratorPrototype();
+
+  if (!proto) {
+    // Invariant holds if there is no array iterator proto.
+    return true;
+  }
+
+  // Ensure that %ArrayIteratorPrototype%'s "next" slot is unchanged.
+  mozilla::Maybe<PropertyInfo> prop = proto->lookupPure(cx->names().next);
+  if (prop.isNothing() || !prop->isDataProperty()) {
+    // Next property has been modified, return false, invariant no longer holds.
+    return false;
+  }
+
+  auto slot = prop->slot();
+
+  const Value& nextVal = proto->getSlot(slot);
+  if (!nextVal.isObject() || !nextVal.toObject().is<JSFunction>()) {
+    // Next property has been modified, return false, invariant no longer holds.
+    return false;
+  }
+
+  auto* nextFun = &nextVal.toObject().as<JSFunction>();
+  return IsSelfHostedFunctionWithName(nextFun, cx->names().ArrayIteratorNext);
+}
+
+static bool HasNoReturnName(JSContext* cx, JS::HandleObject proto) {
+  if (!proto) {
+    // Invariant holds if there is no array iterator proto.
+    return true;
+  }
+
+  JS::RootedId returnName(cx, NameToId(cx->names().return_));
+
+  // An alternative design here would chain together all the has-return-property
+  // fuses such that the fuses each express a stronger invariant; for now these
+  // fuses have only the invariant that each object -itself- has no return
+  // property.
+  bool found = true;
+  if (!HasOwnProperty(cx, proto, returnName, &found)) {
+    cx->recoverFromOutOfMemory();
+    return true;
+  }
+
+  return !found;
+}
+
+/* static */
+bool js::ArrayIteratorPrototypeHasNoReturnProperty::checkInvariant(
+    JSContext* cx) {
+  RootedObject proto(cx, cx->global()->maybeGetArrayIteratorPrototype());
+
+  if (!proto) {
+    // Invariant holds if there is no array iterator proto.
+    return true;
+  }
+
+  return HasNoReturnName(cx, proto);
+}
+
+/* static */
+bool js::IteratorPrototypeHasNoReturnProperty::checkInvariant(JSContext* cx) {
+  RootedObject proto(cx, cx->global()->maybeGetIteratorPrototype());
+
+  if (!proto) {
+    // Invariant holds if there is no array iterator proto.
+    return true;
+  }
+
+  return HasNoReturnName(cx, proto);
+}
+
+/* static */
+bool js::ArrayIteratorPrototypeHasIteratorProto::checkInvariant(JSContext* cx) {
+  RootedObject proto(cx, cx->global()->maybeGetArrayIteratorPrototype());
+  if (!proto) {
+    // Invariant holds if there is no array iterator proto.
+    return true;
+  }
+
+  RootedObject iterProto(cx, cx->global()->maybeGetIteratorPrototype());
+  if (!iterProto) {
+    MOZ_CRASH("Can we have the array iter proto without the iterator proto?");
+    return true;
+  }
+
+  return proto->staticPrototype() == iterProto;
+}
+
+/* static */
+bool js::IteratorPrototypeHasObjectProto::checkInvariant(JSContext* cx) {
+  RootedObject proto(cx, cx->global()->maybeGetIteratorPrototype());
+  if (!proto) {
+    // Invariant holds if there is no array iterator proto.
+    return true;
+  }
+
+  return proto->staticPrototype() == &cx->global()->getObjectPrototype();
+}
+
+/* static */
+bool js::ObjectPrototypeHasNoReturnProperty::checkInvariant(JSContext* cx) {
+  RootedObject proto(cx, &cx->global()->getObjectPrototype());
+  return HasNoReturnName(cx, proto);
+}