1 files changed, 65 insertions, 0 deletions
diff --git a/js/src/frontend/StencilXdr.h b/js/src/frontend/StencilXdr.h
new file mode 100644
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+++ b/js/src/frontend/StencilXdr.h
@@ -0,0 +1,65 @@
+/* -*- 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 frontend_StencilXdr_h
+#define frontend_StencilXdr_h
+
+#include "frontend/ObjLiteral.h"  // ObjLiteralStencil
+#include "frontend/Stencil.h"     // *Stencil
+#include "vm/Scope.h"             // Scope, ScopeKindString
+#include "vm/Xdr.h"               // XDRMode, XDRResult, XDREncoder
+
+namespace js {
+namespace frontend {
+
+// Check that we can copy data to disk and restore it in another instance of
+// the program in a different address space.
+template <typename DataT>
+struct CanCopyDataToDisk {
+  // Check that the object is fully packed, to save disk space.
+#ifdef __cpp_lib_has_unique_object_representations
+  static constexpr bool unique_repr =
+      std::has_unique_object_representations<DataT>();
+#else
+  static constexpr bool unique_repr = true;
+#endif
+
+  // Approximation which assumes that 32bits variant of the class would not
+  // have pointers if the 64bits variant does not have pointer.
+  static constexpr bool no_pointer =
+      alignof(DataT) < alignof(void*) || sizeof(void*) == sizeof(uint32_t);
+
+  static constexpr bool value = unique_repr && no_pointer;
+};
+
+// This is just a namespace class that can be used in friend declarations,
+// so that the statically declared XDR methods within have access to the
+// relevant struct internals.
+class StencilXDR {
+ public:
+  template <XDRMode mode>
+  static XDRResult ScopeData(XDRState<mode>* xdr, ScopeStencil& stencil,
+                             BaseParserScopeData*& baseScopeData);
+
+  template <XDRMode mode, typename ScopeT>
+  static XDRResult ScopeSpecificData(XDRState<mode>* xdr,
+                                     BaseParserScopeData*& baseScopeData);
+
+  template <XDRMode mode>
+  static XDRResult ObjLiteral(XDRState<mode>* xdr, ObjLiteralStencil& stencil);
+
+  template <XDRMode mode>
+  static XDRResult BigInt(XDRState<mode>* xdr, BigIntStencil& stencil);
+
+  template <XDRMode mode>
+  static XDRResult SharedData(js::XDRState<mode>* xdr,
+                              RefPtr<SharedImmutableScriptData>& sisd);
+};
+
+} /* namespace frontend */
+} /* namespace js */
+
+#endif /* frontend_StencilXdr_h */