Allow structs containing mappings in memory.

libsolidity/AST.cpp

@@ -830,11 +830,14 @@ void FunctionCall::checkTypeRequirements(TypePointers const*)
 		return;
 	}
 
+	/// For error message: Struct members that were removed during conversion to memory.
+	set<string> membersRemovedForStructConstructor;
 	if (isStructConstructorCall())
 	{
 		TypeType const& type = dynamic_cast<TypeType const&>(*expressionType);
 		auto const& structType = dynamic_cast<StructType const&>(*type.getActualType());
 		functionType = structType.constructorType();
+		membersRemovedForStructConstructor = structType.membersMissingInMemory();
 	}
 	else
 		functionType = dynamic_pointer_cast<FunctionType const>(expressionType);
@@ -847,13 +850,22 @@ void FunctionCall::checkTypeRequirements(TypePointers const*)
 	// function parameters
 	TypePointers const& parameterTypes = functionType->getParameterTypes();
 	if (!functionType->takesArbitraryParameters() && parameterTypes.size() != m_arguments.size())
-		BOOST_THROW_EXCEPTION(createTypeError(
+	{
+		string msg =
 			"Wrong argument count for function call: " +
 			toString(m_arguments.size()) +
 			" arguments given but expected " +
 			toString(parameterTypes.size()) +
-			"."
+			".";
-		));
+		// Extend error message in case we try to construct a struct with mapping member.
+		if (isStructConstructorCall() && !membersRemovedForStructConstructor.empty())
+		{
+			msg += " Members that have to be skipped in memory:";
+			for (auto const& member: membersRemovedForStructConstructor)
+				msg += " " + member;
+		}
+		BOOST_THROW_EXCEPTION(createTypeError(msg));
+	}
 
 	if (isPositionalCall)
 	{
@@ -972,10 +984,22 @@ void MemberAccess::checkTypeRequirements(TypePointers const* _argumentTypes)
 				++it;
 	}
 	if (possibleMembers.size() == 0)
+	{
+		auto storageType = ReferenceType::copyForLocationIfReference(
+			DataLocation::Storage,
+			m_expression->getType()
+		);
+		if (!storageType->getMembers().membersByName(*m_memberName).empty())
+			BOOST_THROW_EXCEPTION(createTypeError(
+				"Member \"" + *m_memberName + "\" is not available in " +
+				type.toString() +
+				" outside of storage."
+			));
 		BOOST_THROW_EXCEPTION(createTypeError(
 			"Member \"" + *m_memberName + "\" not found or not visible "
 			"after argument-dependent lookup in " + type.toString()
 		));
+	}
 	else if (possibleMembers.size() > 1)
 		BOOST_THROW_EXCEPTION(createTypeError(
 			"Member \"" + *m_memberName + "\" not unique "

libsolidity/Types.cpp

@@ -1040,14 +1040,6 @@ u256 StructType::getStorageSize() const
 	return max<u256>(1, getMembers().getStorageSize());
 }
 
-bool StructType::canLiveOutsideStorage() const
-{
-	for (auto const& member: getMembers())
-		if (!member.type->canLiveOutsideStorage())
-			return false;
-	return true;
-}
-
 string StructType::toString(bool _short) const
 {
 	string ret = "struct " + m_struct.getName();
@@ -1064,9 +1056,13 @@ MemberList const& StructType::getMembers() const
 		MemberList::MemberMap members;
 		for (ASTPointer<VariableDeclaration> const& variable: m_struct.getMembers())
 		{
+			TypePointer type = variable->getType();
+			// Skip all mapping members if we are not in storage.
+			if (location() != DataLocation::Storage && !type->canLiveOutsideStorage())
+				continue;
 			members.push_back(MemberList::Member(
 				variable->getName(),
-				copyForLocationIfReference(variable->getType()),
+				copyForLocationIfReference(type),
 				variable.get())
 			);
 		}
@@ -1077,8 +1073,7 @@ MemberList const& StructType::getMembers() const
 
 TypePointer StructType::copyForLocation(DataLocation _location, bool _isPointer) const
 {
-	auto copy = make_shared<StructType>(m_struct);
+	auto copy = make_shared<StructType>(m_struct, _location);
-	copy->m_location = _location;
 	copy->m_isPointer = _isPointer;
 	return copy;
 }
@@ -1122,6 +1117,15 @@ u256 StructType::memoryOffsetOfMember(string const& _name) const
 	return 0;
 }
 
+set<string> StructType::membersMissingInMemory() const
+{
+	set<string> missing;
+	for (ASTPointer<VariableDeclaration> const& variable: m_struct.getMembers())
+		if (!variable->getType()->canLiveOutsideStorage())
+			missing.insert(variable->getName());
+	return missing;
+}
+
 TypePointer EnumType::unaryOperatorResult(Token::Value _operator) const
 {
 	return _operator == Token::Delete ? make_shared<VoidType>() : TypePointer();

libsolidity/Types.h

@@ -574,14 +574,14 @@ class StructType: public ReferenceType
 {
 public:
 	virtual Category getCategory() const override { return Category::Struct; }
-	explicit StructType(StructDefinition const& _struct):
+	explicit StructType(StructDefinition const& _struct, DataLocation _location = DataLocation::Storage):
-		ReferenceType(DataLocation::Storage), m_struct(_struct) {}
+		ReferenceType(_location), m_struct(_struct) {}
 	virtual bool isImplicitlyConvertibleTo(const Type& _convertTo) const override;
 	virtual bool operator==(Type const& _other) const override;
 	virtual unsigned getCalldataEncodedSize(bool _padded) const override;
 	u256 memorySize() const;
 	virtual u256 getStorageSize() const override;
-	virtual bool canLiveOutsideStorage() const override;
+	virtual bool canLiveOutsideStorage() const override { return true; }
 	virtual std::string toString(bool _short) const override;
 
 	virtual MemberList const& getMembers() const override;
@@ -597,6 +597,9 @@ public:
 
 	StructDefinition const& structDefinition() const { return m_struct; }
 
+	/// @returns the set of all members that are removed in the memory version (typically mappings).
+	std::set<std::string> membersMissingInMemory() const;
+
 private:
 	StructDefinition const& m_struct;
 	/// List of member types, will be lazy-initialized because of recursive references.

test/libsolidity/SolidityEndToEndTest.cpp

@@ -5034,6 +5034,29 @@ BOOST_AUTO_TEST_CASE(literal_strings)
 }
 
 
+BOOST_AUTO_TEST_CASE(memory_structs_with_mappings)
+{
+	char const* sourceCode = R"(
+		contract Test {
+			struct S { uint8 a; mapping(uint => uint) b; uint8 c; }
+			S s;
+			function f() returns (uint) {
+				S memory x;
+				if (x.a != 0 || x.c != 0) return 1;
+				x.a = 4; x.c = 5;
+				s = x;
+				if (s.a != 4 || s.c != 5) return 2;
+				x = S(2, 3);
+				if (x.a != 2 || x.c != 3) return 3;
+				x = s;
+				if (s.a != 4 || s.c != 5) return 4;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Test");
+	BOOST_CHECK(callContractFunction("f()") == encodeArgs(u256(0)));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }

test/libsolidity/SolidityNameAndTypeResolution.cpp

@@ -2134,6 +2134,21 @@ BOOST_AUTO_TEST_CASE(invalid_integer_literal_exp)
 	BOOST_CHECK_THROW(parseTextAndResolveNames(text), TypeError);
 }
 
+BOOST_AUTO_TEST_CASE(memory_structs_with_mappings)
+{
+	char const* text = R"(
+		contract Test {
+			struct S { uint8 a; mapping(uint => uint) b; uint8 c; }
+			S s;
+			function f() {
+				S memory x;
+				x.b[1];
+			}
+		}
+	)";
+	BOOST_CHECK_THROW(parseTextAndResolveNames(text), TypeError);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }