1 files changed, 79 insertions, 0 deletions
diff --git a/src/third_party/mozjs-60/extract/js/src/gc/DeletePolicy.h b/src/third_party/mozjs-60/extract/js/src/gc/DeletePolicy.h
new file mode 100644
index 00000000000..bfa21158dbb
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+++ b/src/third_party/mozjs-60/extract/js/src/gc/DeletePolicy.h
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 gc_DeletePolicy_h
+#define gc_DeletePolicy_h
+
+#include "js/TracingAPI.h"
+
+namespace js {
+namespace gc {
+
+struct ClearEdgesTracer : public JS::CallbackTracer
+{
+    ClearEdgesTracer();
+
+#ifdef DEBUG
+    TracerKind getTracerKind() const override { return TracerKind::ClearEdges; }
+#endif
+
+    template <typename T>
+    inline void clearEdge(T** thingp);
+
+    void onObjectEdge(JSObject** objp) override;
+    void onStringEdge(JSString** strp) override;
+    void onSymbolEdge(JS::Symbol** symp) override;
+    void onScriptEdge(JSScript** scriptp) override;
+    void onShapeEdge(js::Shape** shapep) override;
+    void onObjectGroupEdge(js::ObjectGroup** groupp) override;
+    void onBaseShapeEdge(js::BaseShape** basep) override;
+    void onJitCodeEdge(js::jit::JitCode** codep) override;
+    void onLazyScriptEdge(js::LazyScript** lazyp) override;
+    void onScopeEdge(js::Scope** scopep) override;
+    void onRegExpSharedEdge(js::RegExpShared** sharedp) override;
+    void onChild(const JS::GCCellPtr& thing) override;
+};
+
+#ifdef DEBUG
+inline bool
+IsClearEdgesTracer(JSTracer *trc)
+{
+    return trc->isCallbackTracer() &&
+           trc->asCallbackTracer()->getTracerKind() == JS::CallbackTracer::TracerKind::ClearEdges;
+}
+#endif
+
+} // namespace gc
+
+/*
+ * Provides a delete policy that can be used for objects which have their
+ * lifetime managed by the GC so they can be safely destroyed outside of GC.
+ *
+ * This is necessary for example when initializing such an object may fail after
+ * the initial allocation. The partially-initialized object must be destroyed,
+ * but it may not be safe to do so at the current time as the store buffer may
+ * contain pointers into it.
+ *
+ * This policy traces GC pointers in the object and clears them, making sure to
+ * trigger barriers while doing so. This will remove any store buffer pointers
+ * into the object and make it safe to delete.
+ */
+template <typename T>
+struct GCManagedDeletePolicy
+{
+    void operator()(const T* constPtr) {
+        if (constPtr) {
+            auto ptr = const_cast<T*>(constPtr);
+            gc::ClearEdgesTracer trc;
+            ptr->trace(&trc);
+            js_delete(ptr);
+        }
+    }
+};
+
+} // namespace js
+
+#endif // gc_DeletePolicy_h