1 files changed, 46 insertions, 0 deletions
diff --git a/js/src/util/Memory.h b/js/src/util/Memory.h
new file mode 100644
index 0000000000..e229adbf16
--- /dev/null
+++ b/js/src/util/Memory.h
@@ -0,0 +1,46 @@
+/* -*- 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 util_Memory_h
+#define util_Memory_h
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <type_traits>
+
+static MOZ_ALWAYS_INLINE void* js_memcpy(void* dst_, const void* src_,
+                                         size_t len) {
+  char* dst = (char*)dst_;
+  const char* src = (const char*)src_;
+  MOZ_ASSERT_IF(dst >= src, (size_t)(dst - src) >= len);
+  MOZ_ASSERT_IF(src >= dst, (size_t)(src - dst) >= len);
+
+  return memcpy(dst, src, len);
+}
+
+namespace js {
+
+template <typename T, typename U>
+static constexpr U ComputeByteAlignment(T bytes, U alignment) {
+  static_assert(std::is_unsigned_v<U>, "alignment amount must be unsigned");
+
+  return (alignment - (bytes % alignment)) % alignment;
+}
+
+template <typename T, typename U>
+static constexpr T AlignBytes(T bytes, U alignment) {
+  static_assert(std::is_unsigned_v<U>, "alignment amount must be unsigned");
+
+  return bytes + ComputeByteAlignment(bytes, alignment);
+}
+
+} /* namespace js */
+
+#endif /* util_Memory_h */