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diff --git a/js/src/jit/InterpreterEntryTrampoline.h b/js/src/jit/InterpreterEntryTrampoline.h
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+++ b/js/src/jit/InterpreterEntryTrampoline.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 jit_InterpreterEntryTrampoline_h
+#define jit_InterpreterEntryTrampoline_h
+
+#include "gc/Barrier.h"
+#include "gc/Tracer.h"
+#include "jit/JitCode.h"
+#include "js/AllocPolicy.h"
+#include "js/HashTable.h"
+#include "js/RootingAPI.h"
+
+namespace js {
+
+void ClearInterpreterEntryMap(JSRuntime* runtime);
+
+namespace jit {
+
+/*
+ *  The EntryTrampolineMap is used to cache the trampoline code for
+ *  each script as they are created.  These trampolines are created
+ *  only under --emit-interpreter-entry and are used to identify which
+ *  script is being interpeted when profiling with external profilers
+ *  such as perf.
+ *
+ *  The map owns the JitCode objects that are created for each script,
+ *  and keeps them alive at least as long as the script associated
+ *  with it in case we need to re-enter the trampoline again.
+ *
+ *  As each script is finalized, the entry is manually removed from
+ *  the table in BaseScript::finalize which will also release the
+ *  trampoline code associated with it.
+ *
+ *  During a moving GC, the table is rekeyed in case any scripts
+ *  have relocated.
+ */
+
+class EntryTrampoline {
+  HeapPtr<JitCode*> entryTrampoline_;
+
+ public:
+  void trace(JSTracer* trc) {
+    TraceNullableEdge(trc, &entryTrampoline_, "interpreter-entry-trampoline");
+  }
+
+  explicit EntryTrampoline(JSContext* cx, JitCode* code) {
+    MOZ_ASSERT(code);
+    entryTrampoline_ = code;
+  }
+
+  uint8_t* raw() {
+    MOZ_ASSERT(entryTrampoline_, "Empty trampoline code.");
+    return entryTrampoline_->raw();
+  }
+
+#ifdef JSGC_HASH_TABLE_CHECKS
+  void checkTrampolineAfterMovingGC();
+#endif
+};
+
+using JSScriptToTrampolineMap =
+    HashMap<HeapPtr<BaseScript*>, EntryTrampoline,
+            DefaultHasher<HeapPtr<BaseScript*>>, SystemAllocPolicy>;
+class EntryTrampolineMap : public JSScriptToTrampolineMap {
+ public:
+  void traceTrampolineCode(JSTracer* trc);
+  void updateScriptsAfterMovingGC(void);
+#ifdef JSGC_HASH_TABLE_CHECKS
+  void checkScriptsAfterMovingGC();
+#endif
+};
+
+}  // namespace jit
+}  // namespace js
+#endif /* jit_InterpreterEntryTrampoline_h */