From a828bf5f58982c01c69b8ccf0f2c81eb109071c1 Mon Sep 17 00:00:00 2001
From: Rahul Frias <rfrias@google.com>
Date: Fri, 12 Mar 2021 00:57:07 -0800
Subject: [PATCH] Annotate fallthrough in OEC Testbed

[ Merge of http://go/wvgerrit/119230 ]

This patch adds an annotation to the one place in the codebase where we
intentionally fall through between switch statement cases, in order to
appease stricter compilers.

Bug: 182058081
Test: compile, WV unit/integration tests
Change-Id: I004a6a6e61681fcf22c6bf25d9b0284b8b64e776
---
 libwvdrmengine/cdm/util/include/util_common.h | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/libwvdrmengine/cdm/util/include/util_common.h b/libwvdrmengine/cdm/util/include/util_common.h
index 5e7b1661..7b28c482 100644
--- a/libwvdrmengine/cdm/util/include/util_common.h
+++ b/libwvdrmengine/cdm/util/include/util_common.h
@@ -5,20 +5,27 @@
 #ifndef WVCDM_UTIL_UTIL_COMMON_H_
 #define WVCDM_UTIL_UTIL_COMMON_H_
 
+// This section deals with defines that are platform-specific.
+
 #ifdef _WIN32
+
 #  ifdef CORE_UTIL_IMPLEMENTATION
 #    define CORE_UTIL_EXPORT __declspec(dllexport)
 #  else
 #    define CORE_UTIL_EXPORT __declspec(dllimport)
 #  endif
+
 #  define CORE_UTIL_IGNORE_DEPRECATED
 #  define CORE_UTIL_RESTORE_WARNINGS
+
 #else
+
 #  ifdef CORE_UTIL_IMPLEMENTATION
 #    define CORE_UTIL_EXPORT __attribute__((visibility("default")))
 #  else
 #    define CORE_UTIL_EXPORT
 #  endif
+
 #  ifdef __GNUC__
 #    define CORE_UTIL_IGNORE_DEPRECATED \
       _Pragma("GCC diagnostic push")    \
@@ -28,6 +35,23 @@
 #    define CORE_UTIL_IGNORE_DEPRECATED
 #    define CORE_UTIL_RESTORE_WARNINGS
 #  endif
+
+#endif
+
+// This section deals with attribute-detection and is platform-agnostic.
+
+#if !defined(__has_cpp_attribute)
+#  define __has_cpp_attribute(x) 0
+#endif
+
+#if __has_cpp_attribute(fallthrough)
+#  define CORE_UTIL_FALLTHROUGH [[fallthrough]]
+#elif __has_cpp_attribute(clang::fallthrough)
+#  define CORE_UTIL_FALLTHROUGH [[clang::fallthrough]]
+#elif __has_cpp_attribute(gnu::fallthrough)
+#  define CORE_UTIL_FALLTHROUGH [[gnu::fallthrough]]
+#else
+#  define CORE_UTIL_FALLTHROUGH
 #endif
 
 #endif  // WVCDM_UTIL_UTIL_COMMON_H_