odk: core serialization structs & functions

odk directory copied from wvgerrit.
branch oemcrypto-v16
commit 0c9a7dc

Bug: 140758896
Test: odk_test
Change-Id: I0c631f771b794468a63e4395f6b9c3b60a1dfd4f

libwvdrmengine/oemcrypto/odk/include/odk_overflow.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2019 Google LLC. All Rights Reserved. This file and proprietary
+ * source code may only be used and distributed under the Widevine Master
+ * License Agreement.
+ */
+
+#ifndef ODK_OVERFLOW_H_
+#define ODK_OVERFLOW_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef __has_builtin
+#  define __has_builtin(x) 0
+#endif
+
+#if (defined(__GNUC__) && __GNUC__ >= 5) || \
+    __has_builtin(__builtin_add_overflow)
+#  define odk_sub_overflow_u64 __builtin_sub_overflow
+#  define odk_add_overflow_u64 __builtin_add_overflow
+#  define odk_add_overflow_ux __builtin_add_overflow
+#else
+int odk_sub_overflow_u64(uint64_t a, uint64_t b, uint64_t* c);
+int odk_add_overflow_u64(uint64_t a, uint64_t b, uint64_t* c);
+int odk_add_overflow_ux(size_t a, size_t b, size_t* c);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ODK_OVERFLOW_H_ */