[ORC-RT] Add SPS serialization for std::tuple.

This will be used in upcoming changes to macho_platform.

Author: lhames

compiler-rt/lib/orc/simple_packed_serialization.h

@@ -385,6 +385,44 @@ template <> class SPSSerializationTraits<SPSSequence<char>, span<const char>> {
   }
 };
 
+/// SPSTuple serialization for std::tuple.
+template <typename... SPSTagTs, typename... Ts>
+class SPSSerializationTraits<SPSTuple<SPSTagTs...>, std::tuple<Ts...>> {
+private:
+  using TupleArgList = typename SPSTuple<SPSTagTs...>::AsArgList;
+  using ArgIndices = std::make_index_sequence<sizeof...(Ts)>;
+
+  template <std::size_t... I>
+  static size_t size(const std::tuple<Ts...> &T, std::index_sequence<I...>) {
+    return TupleArgList::size(std::get<I>(T)...);
+  }
+
+  template <std::size_t... I>
+  static bool serialize(SPSOutputBuffer &OB, const std::tuple<Ts...> &T,
+                        std::index_sequence<I...>) {
+    return TupleArgList::serialize(OB, std::get<I>(T)...);
+  }
+
+  template <std::size_t... I>
+  static bool deserialize(SPSInputBuffer &IB, std::tuple<Ts...> &T,
+                          std::index_sequence<I...>) {
+    return TupleArgList::deserialize(IB, std::get<I>(T)...);
+  }
+
+public:
+  static size_t size(const std::tuple<Ts...> &T) {
+    return size(T, ArgIndices{});
+  }
+
+  static bool serialize(SPSOutputBuffer &OB, const std::tuple<Ts...> &T) {
+    return serialize(OB, T, ArgIndices{});
+  }
+
+  static bool deserialize(SPSInputBuffer &IB, std::tuple<Ts...> &T) {
+    return deserialize(IB, T, ArgIndices{});
+  }
+};
+
 /// SPSTuple serialization for std::pair.
 template <typename SPSTagT1, typename SPSTagT2, typename T1, typename T2>
 class SPSSerializationTraits<SPSTuple<SPSTagT1, SPSTagT2>, std::pair<T1, T2>> {

compiler-rt/lib/orc/tests/unit/simple_packed_serialization_test.cpp

@@ -154,6 +154,11 @@ TEST(SimplePackedSerializationTest, SpanSerialization) {
   EXPECT_EQ(InS.data(), Buffer.get() + sizeof(uint64_t));
 }
 
+TEST(SimplePackedSerializationTest, StdTupleSerialization) {
+  std::tuple<int32_t, std::string, bool> P(42, "foo", true);
+  blobSerializationRoundTrip<SPSTuple<int32_t, SPSString, bool>>(P);
+}
+
 TEST(SimplePackedSerializationTest, StdPairSerialization) {
   std::pair<int32_t, std::string> P(42, "foo");
   blobSerializationRoundTrip<SPSTuple<int32_t, SPSString>,