Implement struct encoder.

7 files changed, 177 insertions, 52 deletions

diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 14b30df8..c7843b90 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -1735,7 +1735,15 @@ unsigned StructType::calldataEncodedSize(bool _padded) const
 
 bool StructType::isDynamicallyEncoded() const
 {
-	solAssert(false, "Structs are not yet supported in the ABI.");
+	solAssert(!recursive(), "");
+	for (auto t: memoryMemberTypes())
+	{
+		solAssert(t, "Parameter should have external type.");
+		t = t->interfaceType(false);
+		if (t->isDynamicallyEncoded())
+			return true;
+	}
+	return false;
 }
 
 u256 StructType::memorySize() const
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index dd50c573..cb439693 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -745,7 +745,7 @@ public:
 	virtual MemberList::MemberMap nativeMembers(ContractDefinition const* _currentScope) const override;
 	virtual TypePointer encodingType() const override
 	{
-		return location() == DataLocation::Storage ? std::make_shared<IntegerType>(256) : TypePointer();
+		return location() == DataLocation::Storage ? std::make_shared<IntegerType>(256) : shared_from_this();
 	}
 	virtual TypePointer interfaceType(bool _inLibrary) const override;
 
diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp
index 3a9f1a48..9f6c55ba 100644
--- a/libsolidity/codegen/ABIFunctions.cpp
+++ b/libsolidity/codegen/ABIFunctions.cpp
@@ -404,9 +404,11 @@ string ABIFunctions::abiEncodingFunction(
 		else
 			solAssert(false, "");
 	}
-	else if (dynamic_cast<StructType const*>(&to))
+	else if (auto const* toStruct = dynamic_cast<StructType const*>(&to))
 	{
-		solUnimplementedAssert(false, "Structs not yet implemented.");
+		StructType const* fromStruct = dynamic_cast<StructType const*>(&_from);
+		solAssert(fromStruct, "");
+		return abiEncodingFunctionStruct(*fromStruct, *toStruct, _encodeAsLibraryTypes);
 	}
 	else if (_from.category() == Type::Category::Function)
 		return abiEncodingFunctionFunctionType(
@@ -534,7 +536,7 @@ string ABIFunctions::abiEncodingFunctionSimpleArray(
 					for { let i := 0 } lt(i, length) { i := add(i, 1) }
 					{
 						mstore(pos, sub(tail, headStart))
-						tail := <encodeToMemoryFun>(<arrayElementAccess>(srcPtr), tail)
+						tail := <encodeToMemoryFun>(<arrayElementAccess>, tail)
 						srcPtr := <nextArrayElement>(srcPtr)
 						pos := add(pos, <elementEncodedSize>)
 					}
@@ -549,7 +551,7 @@ string ABIFunctions::abiEncodingFunctionSimpleArray(
 					let srcPtr := <dataAreaFun>(value)
 					for { let i := 0 } lt(i, length) { i := add(i, 1) }
 					{
-						<encodeToMemoryFun>(<arrayElementAccess>(srcPtr), pos)
+						<encodeToMemoryFun>(<arrayElementAccess>, pos)
 						srcPtr := <nextArrayElement>(srcPtr)
 						pos := add(pos, <elementEncodedSize>)
 					}
@@ -573,7 +575,7 @@ string ABIFunctions::abiEncodingFunctionSimpleArray(
 			_encodeAsLibraryTypes,
 			true
 		));
-		templ("arrayElementAccess", inMemory ? "mload" : "sload");
+		templ("arrayElementAccess", inMemory ? "mload(srcPtr)" : _from.baseType()->isValueType() ? "sload(srcPtr)" : "srcPtr" );
 		templ("nextArrayElement", nextArrayElementFunction(_from));
 		return templ.render();
 	});
@@ -726,6 +728,122 @@ string ABIFunctions::abiEncodingFunctionCompactStorageArray(
 	});
 }
 
+string ABIFunctions::abiEncodingFunctionStruct(
+	StructType const& _from,
+	StructType const& _to,
+	bool _encodeAsLibraryTypes
+)
+{
+	string functionName =
+		"abi_encode_" +
+		_from.identifier() +
+		"_to_" +
+		_to.identifier() +
+		(_encodeAsLibraryTypes ? "_library" : "");
+
+	solUnimplementedAssert(!_from.dataStoredIn(DataLocation::CallData), "");
+	solAssert(&_from.structDefinition() == &_to.structDefinition(), "");
+
+	return createFunction(functionName, [&]() {
+		bool fromStorage = _from.location() == DataLocation::Storage;
+		bool dynamic = _to.isDynamicallyEncoded();
+		Whiskers templ(R"(
+			function <functionName>(value, pos) <return> {
+				let tail := add(pos, <headSize>)
+				<init>
+				<#members>
+				{
+					// <memberName>
+					<encode>
+				}
+				</members>
+				<assignEnd>
+			}
+		)");
+		templ("functionName", functionName);
+		templ("return", dynamic ? " -> end " : "");
+		templ("assignEnd", dynamic ? "end := tail" : "");
+		// to avoid multiple loads from the same slot for subsequent members
+		templ("init", fromStorage ? "let slotValue := 0" : "");
+		u256 previousSlotOffset(-1);
+		u256 encodingOffset = 0;
+		vector<map<string, string>> members;
+		for (auto const& member: _to.members(nullptr))
+		{
+			solAssert(member.type, "");
+			if (!member.type->canLiveOutsideStorage())
+				continue;
+			solUnimplementedAssert(
+				member.type->mobileType() &&
+				member.type->mobileType()->interfaceType(_encodeAsLibraryTypes) &&
+				member.type->mobileType()->interfaceType(_encodeAsLibraryTypes)->encodingType(),
+				"Encoding type \"" + member.type->toString() + "\" not yet implemented."
+			);
+			auto memberTypeTo = member.type->mobileType()->interfaceType(_encodeAsLibraryTypes)->encodingType();
+			auto memberTypeFrom = _from.memberType(member.name);
+			solAssert(memberTypeFrom, "");
+			bool dynamicMember = memberTypeTo->isDynamicallyEncoded();
+			if (dynamicMember)
+				solAssert(dynamic, "");
+			Whiskers memberTempl(R"(
+				<preprocess>
+				let memberValue := <retrieveValue>
+				)" + (
+					dynamicMember ?
+					string(R"(
+						mstore(add(pos, <encodingOffset>), sub(tail, pos))
+						tail := <abiEncode>(memberValue, tail)
+					)") :
+					string(R"(
+						<abiEncode>(memberValue, add(pos, <encodingOffset>))
+					)")
+				)
+			);
+			if (fromStorage)
+			{
+				solAssert(memberTypeFrom->isValueType() == memberTypeTo->isValueType(), "");
+				u256 storageSlotOffset;
+				size_t intraSlotOffset;
+				tie(storageSlotOffset, intraSlotOffset) = _from.storageOffsetsOfMember(member.name);
+				if (memberTypeFrom->isValueType())
+				{
+					if (storageSlotOffset != previousSlotOffset)
+					{
+						memberTempl("preprocess", "slotValue := sload(add(value, " + toCompactHexWithPrefix(storageSlotOffset) + "))");
+						previousSlotOffset = storageSlotOffset;
+					}
+					else
+						memberTempl("preprocess", "");
+					memberTempl("retrieveValue", shiftRightFunction(intraSlotOffset * 8, false) + "(slotValue)");
+				}
+				else
+				{
+					solAssert(memberTypeFrom->dataStoredIn(DataLocation::Storage), "");
+					solAssert(intraSlotOffset == 0, "");
+					memberTempl("preprocess", "");
+					memberTempl("retrieveValue", "add(value, " + toCompactHexWithPrefix(storageSlotOffset) + ")");
+				}
+			}
+			else
+			{
+				memberTempl("preprocess", "");
+				string sourceOffset = toCompactHexWithPrefix(_from.memoryOffsetOfMember(member.name));
+				memberTempl("retrieveValue", "mload(add(value, " + sourceOffset + "))");
+			}
+			memberTempl("encodingOffset", toCompactHexWithPrefix(encodingOffset));
+			encodingOffset += dynamicMember ? 0x20 : memberTypeTo->calldataEncodedSize();
+			memberTempl("abiEncode", abiEncodingFunction(*memberTypeFrom, *memberTypeTo, _encodeAsLibraryTypes, false));
+
+			members.push_back({});
+			members.back()["encode"] = memberTempl.render();
+			members.back()["memberName"] = member.name;
+		}
+		templ("members", members);
+		templ("headSize", toCompactHexWithPrefix(encodingOffset));
+		return templ.render();
+	});
+}
+
 string ABIFunctions::abiEncodingFunctionStringLiteral(
 	Type const& _from,
 	Type const& _to,
diff --git a/libsolidity/codegen/ABIFunctions.h b/libsolidity/codegen/ABIFunctions.h
index 5bbd842f..de2a140a 100644
--- a/libsolidity/codegen/ABIFunctions.h
+++ b/libsolidity/codegen/ABIFunctions.h
@@ -123,6 +123,13 @@ private:
 		bool _encodeAsLibraryTypes
 	);
 
+	/// Part of @a abiEncodingFunction for struct types.
+	std::string abiEncodingFunctionStruct(
+		StructType const& _givenType,
+		StructType const& _targetType,
+		bool _encodeAsLibraryTypes
+	);
+
 	// @returns the name of the ABI encoding function with the given type
 	// and queues the generation of the function to the requested functions.
 	// Case for _givenType being a string literal
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index 1e623357..37aa1aea 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -121,7 +121,7 @@ void CompilerUtils::storeInMemoryDynamic(Type const& _type, bool _padToWordBound
 {
 	if (auto ref = dynamic_cast<ReferenceType const*>(&_type))
 	{
-		solAssert(ref->location() == DataLocation::Memory, "");
+		solUnimplementedAssert(ref->location() == DataLocation::Memory, "");
 		storeInMemoryDynamic(IntegerType(256), _padToWordBoundaries);
 	}
 	else if (auto str = dynamic_cast<StringLiteralType const*>(&_type))
diff --git a/test/libsolidity/ABIEncoderTests.cpp b/test/libsolidity/ABIEncoderTests.cpp
index 4ddf17ce..05158601 100644
--- a/test/libsolidity/ABIEncoderTests.cpp
+++ b/test/libsolidity/ABIEncoderTests.cpp
@@ -424,7 +424,43 @@ BOOST_AUTO_TEST_CASE(function_name_collision)
 	)
 }
 
+BOOST_AUTO_TEST_CASE(structs)
+{
+	string sourceCode = R"(
+		contract C {
+			struct S { uint16 a; uint16 b; T[] sub; uint16 c; }
+			struct T { uint64[2] x; }
+			S s;
+			event e(uint16, S);
+			function f() returns (uint, S) {
+				uint16 x = 7;
+				s.a = 8;
+				s.b = 9;
+				s.c = 10;
+				s.sub.length = 3;
+				s.sub[0].x[0] = 11;
+				s.sub[1].x[0] = 12;
+				s.sub[2].x[1] = 13;
+				e(x, s);
+				return (x, s);
+			}
+		}
+	)";
 
+	NEW_ENCODER(
+		compileAndRun(sourceCode, 0, "C");
+		bytes encoded = encodeArgs(
+			u256(7), 0x40,
+			8, 9, 0x80, 10,
+			3,
+			11, 0,
+			12, 0,
+			0, 13
+		);
+		BOOST_CHECK(callContractFunction("f()") == encoded);
+		REQUIRE_LOG_DATA(encoded);
+	)
+}
 
 BOOST_AUTO_TEST_SUITE_END()
 
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 2bdcbd48..f885b0d3 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -9682,50 +9682,6 @@ BOOST_AUTO_TEST_CASE(contracts_separated_with_comment)
 	compileAndRun(sourceCode, 0, "C2");
 }
 
-BOOST_AUTO_TEST_CASE(return_structs)
-{
-	char const* sourceCode = R"(
-		pragma experimental ABIEncoderV2;
-		contract C {
-			struct S { uint a; T[] sub; }
-			struct T { uint[2] x; }
-			function f() returns (uint x, S s) {
-				x = 7;
-				s.a = 8;
-				s.sub = new T[](3);
-				s.sub[0].x[0] = 9;
-				s.sub[1].x[0] = 10;
-				s.sub[2].x[1] = 11;
-			}
-		}
-	)";
-	// This will throw "unimplemented" until it is implemented.
-	BOOST_CHECK_THROW(
-		compileAndRun(sourceCode, 0, "C"),
-		Exception);
-
-//	Will calculate the exact encoding later.
-//	BOOST_CHECK(callContractFunction("f()") == encodeArgs(
-//		u256(7), u256(0x40),
-//		u256(8), u256(0x40),
-//		u256(3),
-//		// s.sub[0]
-//		u256(9), u256(0xc0),
-//		// s.sub[1]
-//		u256(10), u256(0xe0),
-//		// s.sub[2]
-//		u256(11), u256(0x100),
-//		// s.sub[0].sub
-//		u256(2)
-//		// s.sub[0].sub[0].a
-//		u256(8),
-//		u256()
-//		// s.sub[1].sub
-//		u256(0)
-//		// s.sub[2].sub
-//		u256(2)
-//					));
-}
 
 BOOST_AUTO_TEST_CASE(include_creation_bytecode_only_once)
 {