Merge pull request #5936 from ethereum/calldataStructsV2

ABIEncoderV2: Implement calldata structs without dynamically encoded members.

libsolidity/analysis/TypeChecker.cpp

@@ -371,10 +371,12 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 
 		if (
 			!m_scope->isInterface() &&
-			baseType->category() == Type::Category::Struct &&
 			baseType->dataStoredIn(DataLocation::CallData)
 		)
-			m_errorReporter.typeError(var->location(), "Calldata structs are not yet supported.");
+			if (auto const* structType = dynamic_cast<StructType const*>(baseType.get()))
+				if (structType->isDynamicallyEncoded())
+					m_errorReporter.typeError(var->location(), "Dynamically encoded calldata structs are not yet supported.");
+
 		checkArgumentAndReturnParameter(*var);
 		var->accept(*this);
 	}
@@ -2085,8 +2087,8 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 				exprType->toString() + " (expected " + funType->selfType()->toString() + ")."
 			);
 
-	if (exprType->category() == Type::Category::Struct)
-		annotation.isLValue = true;
+	if (auto const* structType = dynamic_cast<StructType const*>(exprType.get()))
+		annotation.isLValue = !structType->dataStoredIn(DataLocation::CallData);
 	else if (exprType->category() == Type::Category::Array)
 	{
 		auto const& arrayType(dynamic_cast<ArrayType const&>(*exprType));

libsolidity/ast/Types.cpp

@@ -2053,6 +2053,24 @@ unsigned StructType::calldataEncodedSize(bool) const
 	return size;
 }
 
+unsigned StructType::calldataOffsetOfMember(std::string const& _member) const
+{
+	unsigned offset = 0;
+	for (auto const& member: members(nullptr))
+	{
+		solAssert(member.type->canLiveOutsideStorage(), "");
+		if (member.name == _member)
+			return offset;
+		{
+			// Struct members are always padded.
+			unsigned memberSize = member.type->calldataEncodedSize(true);
+			solAssert(memberSize != 0, "");
+			offset += memberSize;
+		}
+	}
+	solAssert(false, "Struct member not found.");
+}
+
 bool StructType::isDynamicallyEncoded() const
 {
 	solAssert(!recursive(), "");

libsolidity/ast/Types.h

@@ -852,6 +852,7 @@ public:
 
 	std::pair<u256, unsigned> const& storageOffsetsOfMember(std::string const& _name) const;
 	u256 memoryOffsetOfMember(std::string const& _name) const;
+	unsigned calldataOffsetOfMember(std::string const& _name) const;
 
 	StructDefinition const& structDefinition() const { return m_struct; }
 

libsolidity/codegen/ABIFunctions.cpp

@@ -1246,7 +1246,16 @@ string ABIFunctions::abiDecodingFunction(Type const& _type, bool _fromMemory, bo
 			return abiDecodingFunctionArray(*arrayType, _fromMemory);
 	}
 	else if (auto const* structType = dynamic_cast<StructType const*>(decodingType.get()))
-		return abiDecodingFunctionStruct(*structType, _fromMemory);
+	{
+		if (structType->dataStoredIn(DataLocation::CallData))
+		{
+			solAssert(!_fromMemory, "");
+			solUnimplementedAssert(!structType->isDynamicallyEncoded(), "Dynamically encoded calldata structs are not yet implemented.");
+			return abiDecodingFunctionCalldataStruct(*structType);
+		}
+		else
+			return abiDecodingFunctionStruct(*structType, _fromMemory);
+	}
 	else if (auto const* functionType = dynamic_cast<FunctionType const*>(decodingType.get()))
 		return abiDecodingFunctionFunctionType(*functionType, _fromMemory, _forUseOnStack);
 	else
@@ -1423,15 +1432,37 @@ string ABIFunctions::abiDecodingFunctionByteArray(ArrayType const& _type, bool _
 	});
 }
 
+string ABIFunctions::abiDecodingFunctionCalldataStruct(StructType const& _type)
+{
+	solAssert(_type.dataStoredIn(DataLocation::CallData), "");
+	solAssert(_type.calldataEncodedSize(true) != 0, "");
+	string functionName =
+		"abi_decode_" +
+		_type.identifier();
+
+	return createFunction(functionName, [&]() {
+		Whiskers w{R"(
+				// <readableTypeName>
+				function <functionName>(offset, end) -> value {
+					if slt(sub(end, offset), <minimumSize>) { revert(0, 0) }
+					value := offset
+				}
+		)"};
+		w("functionName", functionName);
+		w("readableTypeName", _type.toString(true));
+		w("minimumSize", to_string(_type.calldataEncodedSize(true)));
+		return w.render();
+	});
+}
+
 string ABIFunctions::abiDecodingFunctionStruct(StructType const& _type, bool _fromMemory)
 {
+	solAssert(!_type.dataStoredIn(DataLocation::CallData), "");
 	string functionName =
 		"abi_decode_" +
 		_type.identifier() +
 		(_fromMemory ? "_fromMemory" : "");
 
-	solUnimplementedAssert(!_type.dataStoredIn(DataLocation::CallData), "");
-
 	return createFunction(functionName, [&]() {
 		Whiskers templ(R"(
 			// <readableTypeName>

libsolidity/codegen/ABIFunctions.h

@@ -222,6 +222,8 @@ private:
 	std::string abiDecodingFunctionCalldataArray(ArrayType const& _type);
 	/// Part of @a abiDecodingFunction for byte array types.
 	std::string abiDecodingFunctionByteArray(ArrayType const& _type, bool _fromMemory);
+	/// Part of @a abiDecodingFunction for calldata struct types.
+	std::string abiDecodingFunctionCalldataStruct(StructType const& _type);
 	/// Part of @a abiDecodingFunction for struct types.
 	std::string abiDecodingFunctionStruct(StructType const& _type, bool _fromMemory);
 	/// Part of @a abiDecodingFunction for array types.

libsolidity/codegen/CompilerUtils.cpp

@@ -918,8 +918,7 @@ void CompilerUtils::convertType(
 		auto& targetType = dynamic_cast<StructType const&>(_targetType);
 		auto& typeOnStack = dynamic_cast<StructType const&>(_typeOnStack);
 		solAssert(
-			targetType.location() != DataLocation::CallData &&
-			typeOnStack.location() != DataLocation::CallData
+			targetType.location() != DataLocation::CallData
 		, "");
 		switch (targetType.location())
 		{
@@ -933,9 +932,9 @@ void CompilerUtils::convertType(
 			break;
 		case DataLocation::Memory:
 			// Copy the array to a free position in memory, unless it is already in memory.
-			if (typeOnStack.location() != DataLocation::Memory)
+			switch (typeOnStack.location())
 			{
-				solAssert(typeOnStack.location() == DataLocation::Storage, "");
+			case DataLocation::Storage:
 				// stack: <source ref>
 				m_context << typeOnStack.memorySize();
 				allocateMemory();
@@ -955,6 +954,19 @@ void CompilerUtils::convertType(
 					storeInMemoryDynamic(*targetMemberType, true);
 				}
 				m_context << Instruction::POP << Instruction::POP;
+				break;
+			case DataLocation::CallData:
+			{
+				solUnimplementedAssert(!typeOnStack.isDynamicallyEncoded(), "");
+				m_context << Instruction::DUP1;
+				m_context << Instruction::CALLDATASIZE;
+				m_context << Instruction::SUB;
+				abiDecode({targetType.shared_from_this()}, false);
+				break;
+			}
+			case DataLocation::Memory:
+				// nothing to do
+				break;
 			}
 			break;
 		case DataLocation::CallData:

libsolidity/codegen/ExpressionCompiler.cpp

@@ -1380,6 +1380,24 @@ bool ExpressionCompiler::visit(MemberAccess const& _memberAccess)
 			setLValue<MemoryItem>(_memberAccess, *_memberAccess.annotation().type);
 			break;
 		}
+		case DataLocation::CallData:
+		{
+			solUnimplementedAssert(!type.isDynamicallyEncoded(), "");
+			m_context << type.calldataOffsetOfMember(member) << Instruction::ADD;
+			// For non-value types the calldata offset is returned directly.
+			if (_memberAccess.annotation().type->isValueType())
+			{
+				solAssert(_memberAccess.annotation().type->calldataEncodedSize(false) > 0, "");
+				CompilerUtils(m_context).loadFromMemoryDynamic(*_memberAccess.annotation().type, true, true, false);
+			}
+			else
+				solAssert(
+					_memberAccess.annotation().type->category() == Type::Category::Array ||
+					_memberAccess.annotation().type->category() == Type::Category::Struct,
+					""
+				);
+			break;
+		}
 		default:
 			solAssert(false, "Illegal data location for struct.");
 		}