1 files changed, 144 insertions, 0 deletions
diff --git a/js/src/gc/Barrier.cpp b/js/src/gc/Barrier.cpp
new file mode 100644
index 0000000000..c0b9d28798
--- /dev/null
+++ b/js/src/gc/Barrier.cpp
@@ -0,0 +1,144 @@
+/* -*- 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 "gc/Barrier.h"
+
+#include "gc/Marking.h"
+#include "jit/JitContext.h"
+#include "js/HashTable.h"
+#include "js/shadow/Zone.h"  // JS::shadow::Zone
+#include "js/Value.h"
+#include "vm/BigIntType.h"  // JS::BigInt
+#include "vm/EnvironmentObject.h"
+#include "vm/GeneratorObject.h"
+#include "vm/JSObject.h"
+#include "vm/PropMap.h"
+#include "wasm/WasmJS.h"
+
+#include "gc/StableCellHasher-inl.h"
+
+namespace js {
+
+bool RuntimeFromMainThreadIsHeapMajorCollecting(JS::shadow::Zone* shadowZone) {
+  MOZ_ASSERT(
+      CurrentThreadCanAccessRuntime(shadowZone->runtimeFromMainThread()));
+  return JS::RuntimeHeapIsMajorCollecting();
+}
+
+#ifdef DEBUG
+
+bool IsMarkedBlack(JSObject* obj) { return obj->isMarkedBlack(); }
+
+bool HeapSlot::preconditionForSet(NativeObject* owner, Kind kind,
+                                  uint32_t slot) const {
+  if (kind == Slot) {
+    return &owner->getSlotRef(slot) == this;
+  }
+
+  uint32_t numShifted = owner->getElementsHeader()->numShiftedElements();
+  MOZ_ASSERT(slot >= numShifted);
+  return &owner->getDenseElement(slot - numShifted) == (const Value*)this;
+}
+
+void HeapSlot::assertPreconditionForPostWriteBarrier(
+    NativeObject* obj, Kind kind, uint32_t slot, const Value& target) const {
+  if (kind == Slot) {
+    MOZ_ASSERT(obj->getSlotAddressUnchecked(slot)->get() == target);
+  } else {
+    uint32_t numShifted = obj->getElementsHeader()->numShiftedElements();
+    MOZ_ASSERT(slot >= numShifted);
+    MOZ_ASSERT(
+        static_cast<HeapSlot*>(obj->getDenseElements() + (slot - numShifted))
+            ->get() == target);
+  }
+
+  if (!obj->zone()->isGCPreparing()) {
+    AssertTargetIsNotGray(obj);
+  }
+}
+
+bool CurrentThreadIsIonCompiling() {
+  jit::JitContext* jcx = jit::MaybeGetJitContext();
+  return jcx && jcx->inIonBackend();
+}
+
+#endif  // DEBUG
+
+#if !MOZ_IS_GCC
+template struct JS_PUBLIC_API StableCellHasher<JSObject*>;
+#endif
+
+}  // namespace js
+
+// Post-write barrier, used by the C++ Heap<T> implementation.
+
+JS_PUBLIC_API void JS::HeapObjectPostWriteBarrier(JSObject** objp,
+                                                  JSObject* prev,
+                                                  JSObject* next) {
+  MOZ_ASSERT(objp);
+  js::InternalBarrierMethods<JSObject*>::postBarrier(objp, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapStringPostWriteBarrier(JSString** strp,
+                                                  JSString* prev,
+                                                  JSString* next) {
+  MOZ_ASSERT(strp);
+  js::InternalBarrierMethods<JSString*>::postBarrier(strp, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapBigIntPostWriteBarrier(JS::BigInt** bip,
+                                                  JS::BigInt* prev,
+                                                  JS::BigInt* next) {
+  MOZ_ASSERT(bip);
+  js::InternalBarrierMethods<JS::BigInt*>::postBarrier(bip, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapValuePostWriteBarrier(JS::Value* valuep,
+                                                 const Value& prev,
+                                                 const Value& next) {
+  MOZ_ASSERT(valuep);
+  js::InternalBarrierMethods<JS::Value>::postBarrier(valuep, prev, next);
+}
+
+// Combined pre- and post-write barriers, used by the rust Heap<T>
+// implementation.
+
+JS_PUBLIC_API void JS::HeapObjectWriteBarriers(JSObject** objp, JSObject* prev,
+                                               JSObject* next) {
+  MOZ_ASSERT(objp);
+  js::InternalBarrierMethods<JSObject*>::preBarrier(prev);
+  js::InternalBarrierMethods<JSObject*>::postBarrier(objp, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapStringWriteBarriers(JSString** strp, JSString* prev,
+                                               JSString* next) {
+  MOZ_ASSERT(strp);
+  js::InternalBarrierMethods<JSString*>::preBarrier(prev);
+  js::InternalBarrierMethods<JSString*>::postBarrier(strp, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapBigIntWriteBarriers(JS::BigInt** bip,
+                                               JS::BigInt* prev,
+                                               JS::BigInt* next) {
+  MOZ_ASSERT(bip);
+  js::InternalBarrierMethods<JS::BigInt*>::preBarrier(prev);
+  js::InternalBarrierMethods<JS::BigInt*>::postBarrier(bip, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapScriptWriteBarriers(JSScript** scriptp,
+                                               JSScript* prev, JSScript* next) {
+  MOZ_ASSERT(scriptp);
+  js::InternalBarrierMethods<JSScript*>::preBarrier(prev);
+  js::InternalBarrierMethods<JSScript*>::postBarrier(scriptp, prev, next);
+}
+
+JS_PUBLIC_API void JS::HeapValueWriteBarriers(JS::Value* valuep,
+                                              const Value& prev,
+                                              const Value& next) {
+  MOZ_ASSERT(valuep);
+  js::InternalBarrierMethods<JS::Value>::preBarrier(prev);
+  js::InternalBarrierMethods<JS::Value>::postBarrier(valuep, prev, next);
+}