Merge pull request #246 from chriseth/refactor

Refactoring - more flexible contracts.

21 files changed, 189 insertions, 247 deletions

diff --git a/libsolidity/analysis/NameAndTypeResolver.cpp b/libsolidity/analysis/NameAndTypeResolver.cpp
index fa894456..612989e1 100644
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@@ -64,7 +64,7 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 	{
 		m_currentScope = &m_scopes[nullptr];
 
-		ReferencesResolver resolver(m_errors, *this, &_contract, nullptr);
+		ReferencesResolver resolver(m_errors, *this, nullptr);
 		bool success = true;
 		for (ASTPointer<InheritanceSpecifier> const& baseContract: _contract.baseContracts())
 			if (!resolver.resolve(*baseContract))
@@ -84,36 +84,11 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 				importInheritedScope(*base);
 		}
 
-		for (ASTPointer<StructDefinition> const& structDef: _contract.definedStructs())
-			if (!resolver.resolve(*structDef))
-				success = false;
-		for (ASTPointer<EnumDefinition> const& enumDef: _contract.definedEnums())
-			if (!resolver.resolve(*enumDef))
-				success = false;
-		for (ASTPointer<VariableDeclaration> const& variable: _contract.stateVariables())
-			if (!resolver.resolve(*variable))
-				success = false;
-		for (ASTPointer<EventDefinition> const& event: _contract.events())
-			if (!resolver.resolve(*event))
-				success = false;
 		// these can contain code, only resolve parameters for now
-		for (ASTPointer<ModifierDefinition> const& modifier: _contract.functionModifiers())
+		for (ASTPointer<ASTNode> const& node: _contract.subNodes())
 		{
-			m_currentScope = &m_scopes[modifier.get()];
-			ReferencesResolver resolver(m_errors, *this, &_contract, nullptr);
-			if (!resolver.resolve(*modifier))
-				success = false;
-		}
-
-		for (ASTPointer<FunctionDefinition> const& function: _contract.definedFunctions())
-		{
-			m_currentScope = &m_scopes[function.get()];
-			if (!ReferencesResolver(
-				m_errors,
-				*this,
-				&_contract,
-				function->returnParameterList().get()
-			).resolve(*function))
+			m_currentScope = &m_scopes[m_scopes.count(node.get()) ? node.get() : &_contract];
+			if (!resolver.resolve(*node))
 				success = false;
 		}
 
@@ -123,21 +98,20 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 		m_currentScope = &m_scopes[&_contract];
 
 		// now resolve references inside the code
-		for (ASTPointer<ModifierDefinition> const& modifier: _contract.functionModifiers())
+		for (ModifierDefinition const* modifier: _contract.functionModifiers())
 		{
-			m_currentScope = &m_scopes[modifier.get()];
-			ReferencesResolver resolver(m_errors, *this, &_contract, nullptr, true);
+			m_currentScope = &m_scopes[modifier];
+			ReferencesResolver resolver(m_errors, *this, nullptr, true);
 			if (!resolver.resolve(*modifier))
 				success = false;
 		}
 
-		for (ASTPointer<FunctionDefinition> const& function: _contract.definedFunctions())
+		for (FunctionDefinition const* function: _contract.definedFunctions())
 		{
-			m_currentScope = &m_scopes[function.get()];
+			m_currentScope = &m_scopes[function];
 			if (!ReferencesResolver(
 				m_errors,
 				*this,
-				&_contract,
 				function->returnParameterList().get(),
 				true
 			).resolve(*function))
diff --git a/libsolidity/analysis/ReferencesResolver.cpp b/libsolidity/analysis/ReferencesResolver.cpp
index f0afc4f9..e5b1c52b 100644
--- a/libsolidity/analysis/ReferencesResolver.cpp
+++ b/libsolidity/analysis/ReferencesResolver.cpp
@@ -50,11 +50,10 @@ bool ReferencesResolver::visit(UserDefinedTypeName const& _typeName)
 
 	_typeName.annotation().referencedDeclaration = declaration;
 
-	_typeName.annotation().contractScope = m_currentContract;
 	return true;
 }
 
-bool ReferencesResolver::resolve(ASTNode& _root)
+bool ReferencesResolver::resolve(ASTNode const& _root)
 {
 	try
 	{
@@ -73,10 +72,7 @@ bool ReferencesResolver::visit(Identifier const& _identifier)
 	if (declarations.empty())
 		fatalDeclarationError(_identifier.location(), "Undeclared identifier.");
 	else if (declarations.size() == 1)
-	{
 		_identifier.annotation().referencedDeclaration = declarations.front();
-		_identifier.annotation().contractScope = m_currentContract;
-	}
 	else
 		_identifier.annotation().overloadedDeclarations =
 			m_resolver.cleanedDeclarations(_identifier, declarations);
diff --git a/libsolidity/analysis/ReferencesResolver.h b/libsolidity/analysis/ReferencesResolver.h
index 62104611..6f5ced8c 100644
--- a/libsolidity/analysis/ReferencesResolver.h
+++ b/libsolidity/analysis/ReferencesResolver.h
@@ -45,19 +45,17 @@ public:
 	ReferencesResolver(
 		ErrorList& _errors,
 		NameAndTypeResolver& _resolver,
-		ContractDefinition const* _currentContract,
 		ParameterList const* _returnParameters,
 		bool _resolveInsideCode = false
 	):
 		m_errors(_errors),
 		m_resolver(_resolver),
-		m_currentContract(_currentContract),
 		m_returnParameters(_returnParameters),
 		m_resolveInsideCode(_resolveInsideCode)
 	{}
 
 	/// @returns true if no errors during resolving
-	bool resolve(ASTNode& _root);
+	bool resolve(ASTNode const& _root);
 
 private:
 	virtual bool visit(Block const&) override { return m_resolveInsideCode; }
@@ -83,7 +81,6 @@ private:
 
 	ErrorList& m_errors;
 	NameAndTypeResolver& m_resolver;
-	ContractDefinition const* m_currentContract;
 	ParameterList const* m_returnParameters;
 	bool const m_resolveInsideCode;
 	bool m_errorOccurred = false;
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 42fdad91..1d2d0258 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -60,7 +60,10 @@ TypePointer const& TypeChecker::type(VariableDeclaration const& _variable) const
 
 bool TypeChecker::visit(ContractDefinition const& _contract)
 {
+	m_scope = &_contract;
+
 	// We force our own visiting order here.
+	//@TODO structs will be visited again below, but it is probably fine.
 	ASTNode::listAccept(_contract.definedStructs(), *this);
 	ASTNode::listAccept(_contract.baseContracts(), *this);
 
@@ -74,7 +77,7 @@ bool TypeChecker::visit(ContractDefinition const& _contract)
 		typeError(function->returnParameterList()->location(), "Non-empty \"returns\" directive for constructor.");
 
 	FunctionDefinition const* fallbackFunction = nullptr;
-	for (ASTPointer<FunctionDefinition> const& function: _contract.definedFunctions())
+	for (FunctionDefinition const* function: _contract.definedFunctions())
 	{
 		if (function->name().empty())
 		{
@@ -86,7 +89,7 @@ bool TypeChecker::visit(ContractDefinition const& _contract)
 			}
 			else
 			{
-				fallbackFunction = function.get();
+				fallbackFunction = function;
 				if (!fallbackFunction->parameters().empty())
 					typeError(fallbackFunction->parameterList().location(), "Fallback function cannot take parameters.");
 			}
@@ -95,10 +98,7 @@ bool TypeChecker::visit(ContractDefinition const& _contract)
 			_contract.annotation().isFullyImplemented = false;
 	}
 
-	ASTNode::listAccept(_contract.stateVariables(), *this);
-	ASTNode::listAccept(_contract.events(), *this);
-	ASTNode::listAccept(_contract.functionModifiers(), *this);
-	ASTNode::listAccept(_contract.definedFunctions(), *this);
+	ASTNode::listAccept(_contract.subNodes(), *this);
 
 	checkContractExternalTypeClashes(_contract);
 	// check for hash collisions in function signatures
@@ -125,8 +125,8 @@ void TypeChecker::checkContractDuplicateFunctions(ContractDefinition const& _con
 	/// Checks that two functions with the same name defined in this contract have different
 	/// argument types and that there is at most one constructor.
 	map<string, vector<FunctionDefinition const*>> functions;
-	for (ASTPointer<FunctionDefinition> const& function: _contract.definedFunctions())
-		functions[function->name()].push_back(function.get());
+	for (FunctionDefinition const* function: _contract.definedFunctions())
+		functions[function->name()].push_back(function);
 
 	// Constructor
 	if (functions[_contract.name()].size() > 1)
@@ -170,7 +170,7 @@ void TypeChecker::checkContractAbstractFunctions(ContractDefinition const& _cont
 
 	// Search from base to derived
 	for (ContractDefinition const* contract: boost::adaptors::reverse(_contract.annotation().linearizedBaseContracts))
-		for (ASTPointer<FunctionDefinition> const& function: contract->definedFunctions())
+		for (FunctionDefinition const* function: contract->definedFunctions())
 		{
 			auto& overloads = functions[function->name()];
 			FunctionTypePointer funType = make_shared<FunctionType>(*function);
@@ -246,7 +246,7 @@ void TypeChecker::checkContractIllegalOverrides(ContractDefinition const& _contr
 	// We search from derived to base, so the stored item causes the error.
 	for (ContractDefinition const* contract: _contract.annotation().linearizedBaseContracts)
 	{
-		for (ASTPointer<FunctionDefinition> const& function: contract->definedFunctions())
+		for (FunctionDefinition const* function: contract->definedFunctions())
 		{
 			if (function->isConstructor())
 				continue; // constructors can neither be overridden nor override anything
@@ -267,14 +267,14 @@ void TypeChecker::checkContractIllegalOverrides(ContractDefinition const& _contr
 				)
 					typeError(overriding->location(), "Override changes extended function signature.");
 			}
-			functions[name].push_back(function.get());
+			functions[name].push_back(function);
 		}
-		for (ASTPointer<ModifierDefinition> const& modifier: contract->functionModifiers())
+		for (ModifierDefinition const* modifier: contract->functionModifiers())
 		{
 			string const& name = modifier->name();
 			ModifierDefinition const*& override = modifiers[name];
 			if (!override)
-				override = modifier.get();
+				override = modifier;
 			else if (ModifierType(*override) != ModifierType(*modifier))
 				typeError(override->location(), "Override changes modifier signature.");
 			if (!functions[name].empty())
@@ -288,20 +288,20 @@ void TypeChecker::checkContractExternalTypeClashes(ContractDefinition const& _co
 	map<string, vector<pair<Declaration const*, FunctionTypePointer>>> externalDeclarations;
 	for (ContractDefinition const* contract: _contract.annotation().linearizedBaseContracts)
 	{
-		for (ASTPointer<FunctionDefinition> const& f: contract->definedFunctions())
+		for (FunctionDefinition const* f: contract->definedFunctions())
 			if (f->isPartOfExternalInterface())
 			{
 				auto functionType = make_shared<FunctionType>(*f);
 				externalDeclarations[functionType->externalSignature()].push_back(
-					make_pair(f.get(), functionType)
+					make_pair(f, functionType)
 				);
 			}
-		for (ASTPointer<VariableDeclaration> const& v: contract->stateVariables())
+		for (VariableDeclaration const* v: contract->stateVariables())
 			if (v->isPartOfExternalInterface())
 			{
 				auto functionType = make_shared<FunctionType>(*v);
 				externalDeclarations[functionType->externalSignature()].push_back(
-					make_pair(v.get(), functionType)
+					make_pair(v, functionType)
 				);
 			}
 	}
@@ -1057,13 +1057,13 @@ void TypeChecker::endVisit(NewExpression const& _newExpression)
 		if (!contract->annotation().isFullyImplemented)
 			typeError(_newExpression.location(), "Trying to create an instance of an abstract contract.");
 
-		auto scopeContract = contractName->annotation().contractScope;
-		scopeContract->annotation().contractDependencies.insert(contract);
+		solAssert(!!m_scope, "");
+		m_scope->annotation().contractDependencies.insert(contract);
 		solAssert(
 			!contract->annotation().linearizedBaseContracts.empty(),
 			"Linearized base contracts not yet available."
 		);
-		if (contractDependenciesAreCyclic(*scopeContract))
+		if (contractDependenciesAreCyclic(*m_scope))
 			typeError(
 				_newExpression.location(),
 				"Circular reference for contract creation (cannot create instance of derived or same contract)."
@@ -1112,7 +1112,7 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 
 	// Retrieve the types of the arguments if this is used to call a function.
 	auto const& argumentTypes = _memberAccess.annotation().argumentTypes;
-	MemberList::MemberMap possibleMembers = exprType->members().membersByName(memberName);
+	MemberList::MemberMap possibleMembers = exprType->members(m_scope).membersByName(memberName);
 	if (possibleMembers.size() > 1 && argumentTypes)
 	{
 		// do overload resolution
@@ -1131,7 +1131,7 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 			DataLocation::Storage,
 			exprType
 		);
-		if (!storageType->members().membersByName(memberName).empty())
+		if (!storageType->members(m_scope).membersByName(memberName).empty())
 			fatalTypeError(
 				_memberAccess.location(),
 				"Member \"" + memberName + "\" is not available in " +
@@ -1258,7 +1258,7 @@ bool TypeChecker::visit(Identifier const& _identifier)
 
 			for (Declaration const* declaration: annotation.overloadedDeclarations)
 			{
-				TypePointer function = declaration->type(_identifier.annotation().contractScope);
+				TypePointer function = declaration->type();
 				solAssert(!!function, "Requested type not present.");
 				auto const* functionType = dynamic_cast<FunctionType const*>(function.get());
 				if (functionType && functionType->canTakeArguments(*annotation.argumentTypes))
@@ -1277,7 +1277,7 @@ bool TypeChecker::visit(Identifier const& _identifier)
 		"Referenced declaration is null after overload resolution."
 	);
 	annotation.isLValue = annotation.referencedDeclaration->isLValue();
-	annotation.type = annotation.referencedDeclaration->type(_identifier.annotation().contractScope);
+	annotation.type = annotation.referencedDeclaration->type();
 	if (!annotation.type)
 		fatalTypeError(_identifier.location(), "Declaration referenced before type could be determined.");
 	return false;
diff --git a/libsolidity/analysis/TypeChecker.h b/libsolidity/analysis/TypeChecker.h
index 2295bc22..9563d4a9 100644
--- a/libsolidity/analysis/TypeChecker.h
+++ b/libsolidity/analysis/TypeChecker.h
@@ -117,6 +117,8 @@ private:
 	/// Runs type checks on @a _expression to infer its type and then checks that it is an LValue.
 	void requireLValue(Expression const& _expression);
 
+	ContractDefinition const* m_scope = nullptr;
+
 	ErrorList& m_errors;
 };
 
diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index 41a4d182..6006d441 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -74,29 +74,29 @@ map<FixedHash<4>, FunctionTypePointer> ContractDefinition::interfaceFunctions()
 
 FunctionDefinition const* ContractDefinition::constructor() const
 {
-	for (ASTPointer<FunctionDefinition> const& f: m_definedFunctions)
+	for (FunctionDefinition const* f: definedFunctions())
 		if (f->isConstructor())
-			return f.get();
+			return f;
 	return nullptr;
 }
 
 FunctionDefinition const* ContractDefinition::fallbackFunction() const
 {
 	for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
-		for (ASTPointer<FunctionDefinition> const& f: contract->definedFunctions())
+		for (FunctionDefinition const* f: contract->definedFunctions())
 			if (f->name().empty())
-				return f.get();
+				return f;
 	return nullptr;
 }
 
-vector<ASTPointer<EventDefinition>> const& ContractDefinition::interfaceEvents() const
+vector<EventDefinition const*> const& ContractDefinition::interfaceEvents() const
 {
 	if (!m_interfaceEvents)
 	{
 		set<string> eventsSeen;
-		m_interfaceEvents.reset(new vector<ASTPointer<EventDefinition>>());
+		m_interfaceEvents.reset(new vector<EventDefinition const*>());
 		for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
-			for (ASTPointer<EventDefinition> const& e: contract->events())
+			for (EventDefinition const* e: contract->events())
 				if (eventsSeen.count(e->name()) == 0)
 				{
 					eventsSeen.insert(e->name());
@@ -116,10 +116,10 @@ vector<pair<FixedHash<4>, FunctionTypePointer>> const& ContractDefinition::inter
 		for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
 		{
 			vector<FunctionTypePointer> functions;
-			for (ASTPointer<FunctionDefinition> const& f: contract->definedFunctions())
+			for (FunctionDefinition const* f: contract->definedFunctions())
 				if (f->isPartOfExternalInterface())
 					functions.push_back(make_shared<FunctionType>(*f, false));
-			for (ASTPointer<VariableDeclaration> const& v: contract->stateVariables())
+			for (VariableDeclaration const* v: contract->stateVariables())
 				if (v->isPartOfExternalInterface())
 					functions.push_back(make_shared<FunctionType>(*v));
 			for (FunctionTypePointer const& fun: functions)
@@ -176,21 +176,21 @@ vector<Declaration const*> const& ContractDefinition::inheritableMembers() const
 			}
 		};
 
-		for (ASTPointer<FunctionDefinition> const& f: definedFunctions())
-			addInheritableMember(f.get());
+		for (FunctionDefinition const* f: definedFunctions())
+			addInheritableMember(f);
 
-		for (ASTPointer<VariableDeclaration> const& v: stateVariables())
-			addInheritableMember(v.get());
+		for (VariableDeclaration const* v: stateVariables())
+			addInheritableMember(v);
 
-		for (ASTPointer<StructDefinition> const& s: definedStructs())
-			addInheritableMember(s.get());
+		for (StructDefinition const* s: definedStructs())
+			addInheritableMember(s);
 	}
 	return *m_inheritableMembers;
 }
 
-TypePointer ContractDefinition::type(ContractDefinition const* m_currentContract) const
+TypePointer ContractDefinition::type() const
 {
-	return make_shared<TypeType>(make_shared<ContractType>(*this), m_currentContract);
+	return make_shared<TypeType>(make_shared<ContractType>(*this));
 }
 
 ContractDefinitionAnnotation& ContractDefinition::annotation() const
@@ -207,7 +207,7 @@ TypeNameAnnotation& TypeName::annotation() const
 	return static_cast<TypeNameAnnotation&>(*m_annotation);
 }
 
-TypePointer StructDefinition::type(ContractDefinition const*) const
+TypePointer StructDefinition::type() const
 {
 	return make_shared<TypeType>(make_shared<StructType>(*this));
 }
@@ -219,14 +219,14 @@ TypeDeclarationAnnotation& StructDefinition::annotation() const
 	return static_cast<TypeDeclarationAnnotation&>(*m_annotation);
 }
 
-TypePointer EnumValue::type(ContractDefinition const*) const
+TypePointer EnumValue::type() const
 {
 	auto parentDef = dynamic_cast<EnumDefinition const*>(scope());
 	solAssert(parentDef, "Enclosing Scope of EnumValue was not set");
 	return make_shared<EnumType>(*parentDef);
 }
 
-TypePointer EnumDefinition::type(ContractDefinition const*) const
+TypePointer EnumDefinition::type() const
 {
 	return make_shared<TypeType>(make_shared<EnumType>(*this));
 }
@@ -238,7 +238,7 @@ TypeDeclarationAnnotation& EnumDefinition::annotation() const
 	return static_cast<TypeDeclarationAnnotation&>(*m_annotation);
 }
 
-TypePointer FunctionDefinition::type(ContractDefinition const*) const
+TypePointer FunctionDefinition::type() const
 {
 	return make_shared<FunctionType>(*this);
 }
@@ -255,7 +255,7 @@ FunctionDefinitionAnnotation& FunctionDefinition::annotation() const
 	return static_cast<FunctionDefinitionAnnotation&>(*m_annotation);
 }
 
-TypePointer ModifierDefinition::type(ContractDefinition const*) const
+TypePointer ModifierDefinition::type() const
 {
 	return make_shared<ModifierType>(*this);
 }
@@ -267,7 +267,7 @@ ModifierDefinitionAnnotation& ModifierDefinition::annotation() const
 	return static_cast<ModifierDefinitionAnnotation&>(*m_annotation);
 }
 
-TypePointer EventDefinition::type(ContractDefinition const*) const
+TypePointer EventDefinition::type() const
 {
 	return make_shared<FunctionType>(*this);
 }
@@ -324,7 +324,7 @@ bool VariableDeclaration::canHaveAutoType() const
 	return (!!callable && !isCallableParameter());
 }
 
-TypePointer VariableDeclaration::type(ContractDefinition const*) const
+TypePointer VariableDeclaration::type() const
 {
 	return annotation().type;
 }
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index e2ed1853..a28d9f4f 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -58,18 +58,22 @@ public:
 	virtual void accept(ASTVisitor& _visitor) = 0;
 	virtual void accept(ASTConstVisitor& _visitor) const = 0;
 	template <class T>
-	static void listAccept(std::vector<ASTPointer<T>>& _list, ASTVisitor& _visitor)
+	static void listAccept(std::vector<T> const& _list, ASTVisitor& _visitor)
 	{
-		for (ASTPointer<T>& element: _list)
+		for (T const& element: _list)
 			element->accept(_visitor);
 	}
 	template <class T>
-	static void listAccept(std::vector<ASTPointer<T>> const& _list, ASTConstVisitor& _visitor)
+	static void listAccept(std::vector<T> const& _list, ASTConstVisitor& _visitor)
 	{
-		for (ASTPointer<T> const& element: _list)
+		for (T const& element: _list)
 			element->accept(_visitor);
 	}
 
+	/// @returns a copy of the vector containing only the nodes which derive from T.
+	template <class _T>
+	static std::vector<_T const*> filteredNodes(std::vector<ASTPointer<ASTNode>> const& _nodes);
+
 	/// Returns the source code location of this node.
 	SourceLocation const& location() const { return m_location; }
 
@@ -95,6 +99,16 @@ private:
 	SourceLocation m_location;
 };
 
+template <class _T>
+std::vector<_T const*> ASTNode::filteredNodes(std::vector<ASTPointer<ASTNode>> const& _nodes)
+{
+	std::vector<_T const*> ret;
+	for (auto const& n: _nodes)
+		if (auto const* nt = dynamic_cast<_T const*>(n.get()))
+			ret.push_back(nt);
+	return ret;
+}
+
 /**
  * Source unit containing import directives and contract definitions.
  */
@@ -168,7 +182,7 @@ public:
 	/// The current contract has to be given since this context can change the type, especially of
 	/// contract types.
 	/// This can only be called once types of variable declarations have already been resolved.
-	virtual TypePointer type(ContractDefinition const* m_currentContract = nullptr) const = 0;
+	virtual TypePointer type() const = 0;
 
 protected:
 	virtual Visibility defaultVisibility() const { return Visibility::Public; }
@@ -238,23 +252,13 @@ public:
 		ASTPointer<ASTString> const& _name,
 		ASTPointer<ASTString> const& _documentation,
 		std::vector<ASTPointer<InheritanceSpecifier>> const& _baseContracts,
-		std::vector<ASTPointer<StructDefinition>> const& _definedStructs,
-		std::vector<ASTPointer<EnumDefinition>> const& _definedEnums,
-		std::vector<ASTPointer<VariableDeclaration>> const& _stateVariables,
-		std::vector<ASTPointer<FunctionDefinition>> const& _definedFunctions,
-		std::vector<ASTPointer<ModifierDefinition>> const& _functionModifiers,
-		std::vector<ASTPointer<EventDefinition>> const& _events,
+		std::vector<ASTPointer<ASTNode>> const& _subNodes,
 		bool _isLibrary
 	):
 		Declaration(_location, _name),
 		Documented(_documentation),
 		m_baseContracts(_baseContracts),
-		m_definedStructs(_definedStructs),
-		m_definedEnums(_definedEnums),
-		m_stateVariables(_stateVariables),
-		m_definedFunctions(_definedFunctions),
-		m_functionModifiers(_functionModifiers),
-		m_events(_events),
+		m_subNodes(_subNodes),
 		m_isLibrary(_isLibrary)
 	{}
 
@@ -262,13 +266,14 @@ public:
 	virtual void accept(ASTConstVisitor& _visitor) const override;
 
 	std::vector<ASTPointer<InheritanceSpecifier>> const& baseContracts() const { return m_baseContracts; }
-	std::vector<ASTPointer<StructDefinition>> const& definedStructs() const { return m_definedStructs; }
-	std::vector<ASTPointer<EnumDefinition>> const& definedEnums() const { return m_definedEnums; }
-	std::vector<ASTPointer<VariableDeclaration>> const& stateVariables() const { return m_stateVariables; }
-	std::vector<ASTPointer<ModifierDefinition>> const& functionModifiers() const { return m_functionModifiers; }
-	std::vector<ASTPointer<FunctionDefinition>> const& definedFunctions() const { return m_definedFunctions; }
-	std::vector<ASTPointer<EventDefinition>> const& events() const { return m_events; }
-	std::vector<ASTPointer<EventDefinition>> const& interfaceEvents() const;
+	std::vector<ASTPointer<ASTNode>> const& subNodes() const { return m_subNodes; }
+	std::vector<StructDefinition const*> definedStructs() const { return filteredNodes<StructDefinition>(m_subNodes); }
+	std::vector<EnumDefinition const*> definedEnums() const { return filteredNodes<EnumDefinition>(m_subNodes); }
+	std::vector<VariableDeclaration const*> stateVariables() const { return filteredNodes<VariableDeclaration>(m_subNodes); }
+	std::vector<ModifierDefinition const*> functionModifiers() const { return filteredNodes<ModifierDefinition>(m_subNodes); }
+	std::vector<FunctionDefinition const*> definedFunctions() const { return filteredNodes<FunctionDefinition>(m_subNodes); }
+	std::vector<EventDefinition const*> events() const { return filteredNodes<EventDefinition>(m_subNodes); }
+	std::vector<EventDefinition const*> const& interfaceEvents() const;
 	bool isLibrary() const { return m_isLibrary; }
 
 	/// @returns a map of canonical function signatures to FunctionDefinitions
@@ -290,18 +295,13 @@ public:
 	std::string const& devDocumentation() const;
 	void setDevDocumentation(std::string const& _devDocumentation);
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual ContractDefinitionAnnotation& annotation() const override;
 
 private:
 	std::vector<ASTPointer<InheritanceSpecifier>> m_baseContracts;
-	std::vector<ASTPointer<StructDefinition>> m_definedStructs;
-	std::vector<ASTPointer<EnumDefinition>> m_definedEnums;
-	std::vector<ASTPointer<VariableDeclaration>> m_stateVariables;
-	std::vector<ASTPointer<FunctionDefinition>> m_definedFunctions;
-	std::vector<ASTPointer<ModifierDefinition>> m_functionModifiers;
-	std::vector<ASTPointer<EventDefinition>> m_events;
+	std::vector<ASTPointer<ASTNode>> m_subNodes;
 	bool m_isLibrary;
 
 	// parsed Natspec documentation of the contract.
@@ -310,7 +310,7 @@ private:
 
 	std::vector<ContractDefinition const*> m_linearizedBaseContracts;
 	mutable std::unique_ptr<std::vector<std::pair<FixedHash<4>, FunctionTypePointer>>> m_interfaceFunctionList;
-	mutable std::unique_ptr<std::vector<ASTPointer<EventDefinition>>> m_interfaceEvents;
+	mutable std::unique_ptr<std::vector<EventDefinition const*>> m_interfaceEvents;
 	mutable std::unique_ptr<std::vector<Declaration const*>> m_inheritableMembers;
 };
 
@@ -350,7 +350,7 @@ public:
 
 	std::vector<ASTPointer<VariableDeclaration>> const& members() const { return m_members; }
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual TypeDeclarationAnnotation& annotation() const override;
 
@@ -372,7 +372,7 @@ public:
 
 	std::vector<ASTPointer<EnumValue>> const& members() const { return m_members; }
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual TypeDeclarationAnnotation& annotation() const override;
 
@@ -392,7 +392,7 @@ public:
 	virtual void accept(ASTVisitor& _visitor) override;
 	virtual void accept(ASTConstVisitor& _visitor) const override;
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 };
 
 /**
@@ -490,7 +490,7 @@ public:
 	/// arguments separated by commas all enclosed in parentheses without any spaces.
 	std::string externalSignature() const;
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual FunctionDefinitionAnnotation& annotation() const override;
 
@@ -551,7 +551,7 @@ public:
 	bool isConstant() const { return m_isConstant; }
 	Location referenceLocation() const { return m_location; }
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual VariableDeclarationAnnotation& annotation() const override;
 
@@ -593,7 +593,7 @@ public:
 
 	Block const& body() const { return *m_body; }
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual ModifierDefinitionAnnotation& annotation() const override;
 
@@ -649,7 +649,7 @@ public:
 
 	bool isAnonymous() const { return m_anonymous; }
 
-	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
+	virtual TypePointer type() const override;
 
 	virtual EventDefinitionAnnotation& annotation() const override;
 
@@ -675,7 +675,7 @@ public:
 		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("MagicVariableDeclaration used inside real AST."));
 	}
 
-	virtual TypePointer type(ContractDefinition const*) const override { return m_type; }
+	virtual TypePointer type() const override { return m_type; }
 
 private:
 	std::shared_ptr<Type const> m_type;
diff --git a/libsolidity/ast/ASTAnnotations.h b/libsolidity/ast/ASTAnnotations.h
index b9667302..4e0187cf 100644
--- a/libsolidity/ast/ASTAnnotations.h
+++ b/libsolidity/ast/ASTAnnotations.h
@@ -138,9 +138,6 @@ struct ExpressionAnnotation: ASTAnnotation
 
 struct IdentifierAnnotation: ExpressionAnnotation
 {
-	/// Stores a reference to the current contract.
-	/// This is needed because types of base contracts change depending on the context.
-	ContractDefinition const* contractScope = nullptr;
 	/// Referenced declaration, set at latest during overload resolution stage.
 	Declaration const* referencedDeclaration = nullptr;
 	/// List of possible declarations it could refer to.
diff --git a/libsolidity/ast/AST_accept.h b/libsolidity/ast/AST_accept.h
index 99d1bf6a..f65595b8 100644
--- a/libsolidity/ast/AST_accept.h
+++ b/libsolidity/ast/AST_accept.h
@@ -62,12 +62,7 @@ void ContractDefinition::accept(ASTVisitor& _visitor)
 	if (_visitor.visit(*this))
 	{
 		listAccept(m_baseContracts, _visitor);
-		listAccept(m_definedStructs, _visitor);
-		listAccept(m_definedEnums, _visitor);
-		listAccept(m_stateVariables, _visitor);
-		listAccept(m_events, _visitor);
-		listAccept(m_functionModifiers, _visitor);
-		listAccept(m_definedFunctions, _visitor);
+		listAccept(m_subNodes, _visitor);
 	}
 	_visitor.endVisit(*this);
 }
@@ -77,12 +72,7 @@ void ContractDefinition::accept(ASTConstVisitor& _visitor) const
 	if (_visitor.visit(*this))
 	{
 		listAccept(m_baseContracts, _visitor);
-		listAccept(m_definedStructs, _visitor);
-		listAccept(m_definedEnums, _visitor);
-		listAccept(m_stateVariables, _visitor);
-		listAccept(m_events, _visitor);
-		listAccept(m_functionModifiers, _visitor);
-		listAccept(m_definedFunctions, _visitor);
+		listAccept(m_subNodes, _visitor);
 	}
 	_visitor.endVisit(*this);
 }
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index cb97eae8..96f44571 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -858,7 +858,7 @@ string ArrayType::canonicalName(bool _addDataLocation) const
 	return ret;
 }
 
-MemberList const& ArrayType::members() const
+MemberList const& ArrayType::members(ContractDefinition const*) const
 {
 	if (!m_members)
 	{
@@ -956,7 +956,7 @@ string ContractType::canonicalName(bool) const
 	return m_contract.annotation().canonicalName;
 }
 
-MemberList const& ContractType::members() const
+MemberList const& ContractType::members(ContractDefinition const*) const
 {
 	// We need to lazy-initialize it because of recursive references.
 	if (!m_members)
@@ -970,7 +970,7 @@ MemberList const& ContractType::members() const
 		{
 			// add the most derived of all functions which are visible in derived contracts
 			for (ContractDefinition const* base: m_contract.annotation().linearizedBaseContracts)
-				for (ASTPointer<FunctionDefinition> const& function: base->definedFunctions())
+				for (FunctionDefinition const* function: base->definedFunctions())
 				{
 					if (!function->isVisibleInDerivedContracts())
 						continue;
@@ -991,7 +991,7 @@ MemberList const& ContractType::members() const
 						members.push_back(MemberList::Member(
 							function->name(),
 							functionType,
-							function.get()
+							function
 						));
 				}
 		}
@@ -1024,9 +1024,9 @@ vector<tuple<VariableDeclaration const*, u256, unsigned>> ContractType::stateVar
 {
 	vector<VariableDeclaration const*> variables;
 	for (ContractDefinition const* contract: boost::adaptors::reverse(m_contract.annotation().linearizedBaseContracts))
-		for (ASTPointer<VariableDeclaration> const& variable: contract->stateVariables())
+		for (VariableDeclaration const* variable: contract->stateVariables())
 			if (!variable->isConstant())
-				variables.push_back(variable.get());
+				variables.push_back(variable);
 	TypePointers types;
 	for (auto variable: variables)
 		types.push_back(variable->annotation().type);
@@ -1064,7 +1064,7 @@ bool StructType::operator==(Type const& _other) const
 unsigned StructType::calldataEncodedSize(bool _padded) const
 {
 	unsigned size = 0;
-	for (auto const& member: members())
+	for (auto const& member: members(nullptr))
 		if (!member.type->canLiveOutsideStorage())
 			return 0;
 		else
@@ -1080,7 +1080,7 @@ unsigned StructType::calldataEncodedSize(bool _padded) const
 u256 StructType::memorySize() const
 {
 	u256 size;
-	for (auto const& member: members())
+	for (auto const& member: members(nullptr))
 		if (member.type->canLiveOutsideStorage())
 			size += member.type->memoryHeadSize();
 	return size;
@@ -1088,7 +1088,7 @@ u256 StructType::memorySize() const
 
 u256 StructType::storageSize() const
 {
-	return max<u256>(1, members().storageSize());
+	return max<u256>(1, members(nullptr).storageSize());
 }
 
 string StructType::toString(bool _short) const
@@ -1099,7 +1099,7 @@ string StructType::toString(bool _short) const
 	return ret;
 }
 
-MemberList const& StructType::members() const
+MemberList const& StructType::members(ContractDefinition const*) const
 {
 	// We need to lazy-initialize it because of recursive references.
 	if (!m_members)
@@ -1149,7 +1149,7 @@ FunctionTypePointer StructType::constructorType() const
 {
 	TypePointers paramTypes;
 	strings paramNames;
-	for (auto const& member: members())
+	for (auto const& member: members(nullptr))
 	{
 		if (!member.type->canLiveOutsideStorage())
 			continue;
@@ -1167,7 +1167,7 @@ FunctionTypePointer StructType::constructorType() const
 
 pair<u256, unsigned> const& StructType::storageOffsetsOfMember(string const& _name) const
 {
-	auto const* offsets = members().memberStorageOffset(_name);
+	auto const* offsets = members(nullptr).memberStorageOffset(_name);
 	solAssert(offsets, "Storage offset of non-existing member requested.");
 	return *offsets;
 }
@@ -1175,7 +1175,7 @@ pair<u256, unsigned> const& StructType::storageOffsetsOfMember(string const& _na
 u256 StructType::memoryOffsetOfMember(string const& _name) const
 {
 	u256 offset;
-	for (auto const& member: members())
+	for (auto const& member: members(nullptr))
 		if (member.name == _name)
 			return offset;
 		else
@@ -1395,7 +1395,7 @@ FunctionType::FunctionType(VariableDeclaration const& _varDecl):
 	vector<string> retParamNames;
 	if (auto structType = dynamic_cast<StructType const*>(returnType.get()))
 	{
-		for (auto const& member: structType->members())
+		for (auto const& member: structType->members(nullptr))
 			if (member.type->category() != Category::Mapping)
 			{
 				if (auto arrayType = dynamic_cast<ArrayType const*>(member.type.get()))
@@ -1533,7 +1533,7 @@ FunctionTypePointer FunctionType::interfaceFunctionType() const
 	return make_shared<FunctionType>(paramTypes, retParamTypes, m_parameterNames, m_returnParameterNames, m_location, m_arbitraryParameters);
 }
 
-MemberList const& FunctionType::members() const
+MemberList const& FunctionType::members(ContractDefinition const*) const
 {
 	switch (m_location)
 	{
@@ -1784,10 +1784,10 @@ unsigned TypeType::sizeOnStack() const
 	return 0;
 }
 
-MemberList const& TypeType::members() const
+MemberList const& TypeType::members(ContractDefinition const* _currentScope) const
 {
 	// We need to lazy-initialize it because of recursive references.
-	if (!m_members)
+	if (!m_members || m_cachedScope != _currentScope)
 	{
 		MemberList::MemberMap members;
 		if (m_actualType->category() == Category::Contract)
@@ -1800,9 +1800,9 @@ MemberList const& TypeType::members() const
 						it.second->asMemberFunction(true), // use callcode
 						&it.second->declaration()
 					));
-			else if (m_currentContract != nullptr)
+			else if (_currentScope != nullptr)
 			{
-				auto const& currentBases = m_currentContract->annotation().linearizedBaseContracts;
+				auto const& currentBases = _currentScope->annotation().linearizedBaseContracts;
 				if (find(currentBases.begin(), currentBases.end(), &contract) != currentBases.end())
 					// We are accessing the type of a base contract, so add all public and protected
 					// members. Note that this does not add inherited functions on purpose.
@@ -1818,6 +1818,7 @@ MemberList const& TypeType::members() const
 				members.push_back(MemberList::Member(enumValue->name(), enumType));
 		}
 		m_members.reset(new MemberList(members));
+		m_cachedScope = _currentScope;
 	}
 	return *m_members;
 }
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index 63207a51..f841a1be 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -217,9 +217,13 @@ public:
 	}
 
 	/// Returns the list of all members of this type. Default implementation: no members.
-	virtual MemberList const& members() const { return EmptyMemberList; }
+	/// @param _currentScope scope in which the members are accessed.
+	virtual MemberList const& members(ContractDefinition const* /*_currentScope*/) const { return EmptyMemberList; }
 	/// Convenience method, returns the type of the given named member or an empty pointer if no such member exists.
-	TypePointer memberType(std::string const& _name) const { return members().memberType(_name); }
+	TypePointer memberType(std::string const& _name, ContractDefinition const* _currentScope = nullptr) const
+	{
+		return members(_currentScope).memberType(_name);
+	}
 
 	virtual std::string toString(bool _short) const = 0;
 	std::string toString() const { return toString(false); }
@@ -277,7 +281,10 @@ public:
 	virtual unsigned storageBytes() const override { return m_bits / 8; }
 	virtual bool isValueType() const override { return true; }
 
-	virtual MemberList const& members() const override { return isAddress() ? AddressMemberList : EmptyMemberList; }
+	virtual MemberList const& members(ContractDefinition const* /*_currentScope*/) const override
+	{
+		return isAddress() ? AddressMemberList : EmptyMemberList;
+	}
 
 	virtual std::string toString(bool _short) const override;
 
@@ -510,7 +517,7 @@ public:
 	virtual unsigned sizeOnStack() const override;
 	virtual std::string toString(bool _short) const override;
 	virtual std::string canonicalName(bool _addDataLocation) const override;
-	virtual MemberList const& members() const override;
+	virtual MemberList const& members(ContractDefinition const* _currentScope) const override;
 	virtual TypePointer encodingType() const override;
 	virtual TypePointer decodingType() const override;
 	virtual TypePointer interfaceType(bool _inLibrary) const override;
@@ -563,7 +570,7 @@ public:
 	virtual std::string toString(bool _short) const override;
 	virtual std::string canonicalName(bool _addDataLocation) const override;
 
-	virtual MemberList const& members() const override;
+	virtual MemberList const& members(ContractDefinition const* _currentScope) const override;
 	virtual TypePointer encodingType() const override
 	{
 		return std::make_shared<IntegerType>(160, IntegerType::Modifier::Address);
@@ -616,7 +623,7 @@ public:
 	virtual bool canLiveOutsideStorage() const override { return true; }
 	virtual std::string toString(bool _short) const override;
 
-	virtual MemberList const& members() const override;
+	virtual MemberList const& members(ContractDefinition const* _currentScope) const override;
 	virtual TypePointer encodingType() const override
 	{
 		return location() == DataLocation::Storage ? std::make_shared<IntegerType>(256) : TypePointer();
@@ -810,7 +817,7 @@ public:
 	virtual u256 storageSize() const override;
 	virtual bool canLiveOutsideStorage() const override { return false; }
 	virtual unsigned sizeOnStack() const override;
-	virtual MemberList const& members() const override;
+	virtual MemberList const& members(ContractDefinition const* _currentScope) const override;
 
 	/// @returns TypePointer of a new FunctionType object. All input/return parameters are an
 	/// appropriate external types (i.e. the interfaceType()s) of input/return parameters of
@@ -918,8 +925,7 @@ class TypeType: public Type
 {
 public:
 	virtual Category category() const override { return Category::TypeType; }
-	explicit TypeType(TypePointer const& _actualType, ContractDefinition const* _currentContract = nullptr):
-		m_actualType(_actualType), m_currentContract(_currentContract) {}
+	explicit TypeType(TypePointer const& _actualType): m_actualType(_actualType) {}
 	TypePointer const& actualType() const { return m_actualType; }
 
 	virtual TypePointer binaryOperatorResult(Token::Value, TypePointer const&) const override { return TypePointer(); }
@@ -929,14 +935,13 @@ public:
 	virtual bool canLiveOutsideStorage() const override { return false; }
 	virtual unsigned sizeOnStack() const override;
 	virtual std::string toString(bool _short) const override { return "type(" + m_actualType->toString(_short) + ")"; }
-	virtual MemberList const& members() const override;
+	virtual MemberList const& members(ContractDefinition const* _currentScope) const override;
 
 private:
 	TypePointer m_actualType;
-	/// Context in which this type is used (influences visibility etc.), can be nullptr.
-	ContractDefinition const* m_currentContract;
 	/// List of member types, will be lazy-initialized because of recursive references.
 	mutable std::unique_ptr<MemberList> m_members;
+	mutable ContractDefinition const* m_cachedScope = nullptr;
 };
 
 
@@ -983,7 +988,7 @@ public:
 	virtual bool canBeStored() const override { return false; }
 	virtual bool canLiveOutsideStorage() const override { return true; }
 	virtual unsigned sizeOnStack() const override { return 0; }
-	virtual MemberList const& members() const override { return m_members; }
+	virtual MemberList const& members(ContractDefinition const*) const override { return m_members; }
 
 	virtual std::string toString(bool _short) const override;
 
diff --git a/libsolidity/codegen/Compiler.cpp b/libsolidity/codegen/Compiler.cpp
index 055e607f..f1d95980 100644
--- a/libsolidity/codegen/Compiler.cpp
+++ b/libsolidity/codegen/Compiler.cpp
@@ -385,7 +385,7 @@ void Compiler::registerStateVariables(ContractDefinition const& _contract)
 
 void Compiler::initializeStateVariables(ContractDefinition const& _contract)
 {
-	for (ASTPointer<VariableDeclaration> const& variable: _contract.stateVariables())
+	for (VariableDeclaration const* variable: _contract.stateVariables())
 		if (variable->value() && !variable->isConstant())
 			ExpressionCompiler(m_context, m_optimize).appendStateVariableInitialization(*variable);
 }
diff --git a/libsolidity/codegen/CompilerContext.cpp b/libsolidity/codegen/CompilerContext.cpp
index 00b9d87c..9e2405cc 100644
--- a/libsolidity/codegen/CompilerContext.cpp
+++ b/libsolidity/codegen/CompilerContext.cpp
@@ -133,9 +133,9 @@ ModifierDefinition const& CompilerContext::functionModifier(string const& _name)
 {
 	solAssert(!m_inheritanceHierarchy.empty(), "No inheritance hierarchy set.");
 	for (ContractDefinition const* contract: m_inheritanceHierarchy)
-		for (ASTPointer<ModifierDefinition> const& modifier: contract->functionModifiers())
+		for (ModifierDefinition const* modifier: contract->functionModifiers())
 			if (modifier->name() == _name)
-				return *modifier.get();
+				return *modifier;
 	BOOST_THROW_EXCEPTION(InternalCompilerError()
 		<< errinfo_comment("Function modifier " + _name + " not found."));
 }
@@ -195,7 +195,7 @@ eth::AssemblyItem CompilerContext::virtualFunctionEntryLabel(
 	FunctionType functionType(_function);
 	auto it = _searchStart;
 	for (; it != m_inheritanceHierarchy.end(); ++it)
-		for (ASTPointer<FunctionDefinition> const& function: (*it)->definedFunctions())
+		for (FunctionDefinition const* function: (*it)->definedFunctions())
 			if (
 				function->name() == name &&
 				!function->isConstructor() &&
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index 357013e6..b57f5b29 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -542,7 +542,7 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
 				allocateMemory();
 				m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2;
 				// stack: <memory ptr> <source ref> <memory ptr>
-				for (auto const& member: typeOnStack.members())
+				for (auto const& member: typeOnStack.members(nullptr))
 				{
 					if (!member.type->canLiveOutsideStorage())
 						continue;
@@ -642,7 +642,7 @@ void CompilerUtils::pushZeroValue(Type const& _type)
 	m_context << eth::Instruction::DUP1;
 
 	if (auto structType = dynamic_cast<StructType const*>(&_type))
-		for (auto const& member: structType->members())
+		for (auto const& member: structType->members(nullptr))
 		{
 			pushZeroValue(*member.type);
 			storeInMemoryDynamic(*member.type);
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index c94c988b..6c288ae7 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -888,10 +888,6 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 	case Type::Category::TypeType:
 	{
 		TypeType const& type = dynamic_cast<TypeType const&>(*_memberAccess.expression().annotation().type);
-		solAssert(
-			!type.members().membersByName(_memberAccess.memberName()).empty(),
-			"Invalid member access to " + type.toString(false)
-		);
 
 		if (dynamic_cast<ContractType const*>(type.actualType().get()))
 		{
@@ -1043,11 +1039,11 @@ void ExpressionCompiler::endVisit(Identifier const& _identifier)
 	Declaration const* declaration = _identifier.annotation().referencedDeclaration;
 	if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
 	{
-		switch (magicVar->type(_identifier.annotation().contractScope)->category())
+		switch (magicVar->type()->category())
 		{
 		case Type::Category::Contract:
 			// "this" or "super"
-			if (!dynamic_cast<ContractType const&>(*magicVar->type(_identifier.annotation().contractScope)).isSuper())
+			if (!dynamic_cast<ContractType const&>(*magicVar->type()).isSuper())
 				m_context << eth::Instruction::ADDRESS;
 			break;
 		case Type::Category::Integer:
diff --git a/libsolidity/codegen/LValue.cpp b/libsolidity/codegen/LValue.cpp
index 864f28d0..fdef6937 100644
--- a/libsolidity/codegen/LValue.cpp
+++ b/libsolidity/codegen/LValue.cpp
@@ -273,7 +273,7 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc
 				"Struct assignment with conversion."
 			);
 			solAssert(sourceType.location() != DataLocation::CallData, "Structs in calldata not supported.");
-			for (auto const& member: structType.members())
+			for (auto const& member: structType.members(nullptr))
 			{
 				// assign each member that is not a mapping
 				TypePointer const& memberType = member.type;
@@ -336,7 +336,7 @@ void StorageItem::setToZero(SourceLocation const&, bool _removeReference) const
 		// @todo this can be improved: use StorageItem for non-value types, and just store 0 in
 		// all slots that contain value types later.
 		auto const& structType = dynamic_cast<StructType const&>(*m_dataType);
-		for (auto const& member: structType.members())
+		for (auto const& member: structType.members(nullptr))
 		{
 			// zero each member that is not a mapping
 			TypePointer const& memberType = member.type;
diff --git a/libsolidity/formal/Why3Translator.cpp b/libsolidity/formal/Why3Translator.cpp
index fe3729d4..5028e2c3 100644
--- a/libsolidity/formal/Why3Translator.cpp
+++ b/libsolidity/formal/Why3Translator.cpp
@@ -145,8 +145,8 @@ bool Why3Translator::visit(ContractDefinition const& _contract)
 
 	addLine("type state = {");
 	indent();
-	m_stateVariables = &_contract.stateVariables();
-	for (auto const& variable: _contract.stateVariables())
+	m_stateVariables = _contract.stateVariables();
+	for (VariableDeclaration const* variable: m_stateVariables)
 	{
 		string varType = toFormalType(*variable->annotation().type);
 		if (varType.empty())
@@ -174,7 +174,7 @@ bool Why3Translator::visit(ContractDefinition const& _contract)
 
 void Why3Translator::endVisit(ContractDefinition const& _contract)
 {
-	m_stateVariables = nullptr;
+	m_stateVariables.clear();
 	addSourceFromDocStrings(_contract.annotation());
 	unindent();
 	addLine("end");
@@ -600,17 +600,12 @@ bool Why3Translator::visit(Literal const& _literal)
 
 bool Why3Translator::isStateVariable(VariableDeclaration const* _var) const
 {
-	solAssert(!!m_stateVariables, "");
-	for (auto const& var: *m_stateVariables)
-		if (var.get() == _var)
-			return true;
-	return false;
+	return contains(m_stateVariables, _var);
 }
 
 bool Why3Translator::isStateVariable(string const& _name) const
 {
-	solAssert(!!m_stateVariables, "");
-	for (auto const& var: *m_stateVariables)
+	for (auto const& var: m_stateVariables)
 		if (var->name() == _name)
 			return true;
 	return false;
diff --git a/libsolidity/formal/Why3Translator.h b/libsolidity/formal/Why3Translator.h
index e5c298b4..f4315a7a 100644
--- a/libsolidity/formal/Why3Translator.h
+++ b/libsolidity/formal/Why3Translator.h
@@ -117,7 +117,7 @@ private:
 	bool m_seenContract = false;
 	bool m_errorOccured = false;
 
-	std::vector<ASTPointer<VariableDeclaration>> const* m_stateVariables = nullptr;
+	std::vector<VariableDeclaration const*> m_stateVariables;
 	std::map<std::string, VariableDeclaration const*> m_localVariables;
 
 	struct Line
diff --git a/libsolidity/interface/InterfaceHandler.cpp b/libsolidity/interface/InterfaceHandler.cpp
index 30cd9724..e254137f 100644
--- a/libsolidity/interface/InterfaceHandler.cpp
+++ b/libsolidity/interface/InterfaceHandler.cpp
@@ -120,7 +120,7 @@ string InterfaceHandler::ABISolidityInterface(ContractDefinition const& _contrac
 		{
 			ret += "struct " + stru->name() + "{";
 			for (ASTPointer<VariableDeclaration> const& _member: stru->members())
-				ret += _member->type(nullptr)->canonicalName(false) + " " + _member->name() + ";";
+				ret += _member->type()->canonicalName(false) + " " + _member->name() + ";";
 			ret += "}";
 		}
 		for (auto const& enu: _contractDef.definedEnums())
diff --git a/libsolidity/parsing/Parser.cpp b/libsolidity/parsing/Parser.cpp
index 2d4ca43e..9272eb4b 100644
--- a/libsolidity/parsing/Parser.cpp
+++ b/libsolidity/parsing/Parser.cpp
@@ -132,12 +132,6 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition(bool _isLibrary)
 	expectToken(_isLibrary ? Token::Library : Token::Contract);
 	ASTPointer<ASTString> name = expectIdentifierToken();
 	vector<ASTPointer<InheritanceSpecifier>> baseContracts;
-	vector<ASTPointer<StructDefinition>> structs;
-	vector<ASTPointer<EnumDefinition>> enums;
-	vector<ASTPointer<VariableDeclaration>> stateVariables;
-	vector<ASTPointer<FunctionDefinition>> functions;
-	vector<ASTPointer<ModifierDefinition>> modifiers;
-	vector<ASTPointer<EventDefinition>> events;
 	if (m_scanner->currentToken() == Token::Is)
 		do
 		{
@@ -145,6 +139,7 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition(bool _isLibrary)
 			baseContracts.push_back(parseInheritanceSpecifier());
 		}
 		while (m_scanner->currentToken() == Token::Comma);
+	vector<ASTPointer<ASTNode>> subNodes;
 	expectToken(Token::LBrace);
 	while (true)
 	{
@@ -152,11 +147,11 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition(bool _isLibrary)
 		if (currentTokenValue == Token::RBrace)
 			break;
 		else if (currentTokenValue == Token::Function)
-			functions.push_back(parseFunctionDefinition(name.get()));
+			subNodes.push_back(parseFunctionDefinition(name.get()));
 		else if (currentTokenValue == Token::Struct)
-			structs.push_back(parseStructDefinition());
+			subNodes.push_back(parseStructDefinition());
 		else if (currentTokenValue == Token::Enum)
-			enums.push_back(parseEnumDefinition());
+			subNodes.push_back(parseEnumDefinition());
 		else if (
 			currentTokenValue == Token::Identifier ||
 			currentTokenValue == Token::Mapping ||
@@ -166,13 +161,13 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition(bool _isLibrary)
 			VarDeclParserOptions options;
 			options.isStateVariable = true;
 			options.allowInitialValue = true;
-			stateVariables.push_back(parseVariableDeclaration(options));
+			subNodes.push_back(parseVariableDeclaration(options));
 			expectToken(Token::Semicolon);
 		}
 		else if (currentTokenValue == Token::Modifier)
-			modifiers.push_back(parseModifierDefinition());
+			subNodes.push_back(parseModifierDefinition());
 		else if (currentTokenValue == Token::Event)
-			events.push_back(parseEventDefinition());
+			subNodes.push_back(parseEventDefinition());
 		else
 			fatalParserError(std::string("Function, variable, struct or modifier declaration expected."));
 	}
@@ -182,12 +177,7 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition(bool _isLibrary)
 		name,
 		docString,
 		baseContracts,
-		structs,
-		enums,
-		stateVariables,
-		functions,
-		modifiers,
-		events,
+		subNodes,
 		_isLibrary
 	);
 }
diff --git a/test/libsolidity/SolidityParser.cpp b/test/libsolidity/SolidityParser.cpp
index beb71942..7451397e 100644
--- a/test/libsolidity/SolidityParser.cpp
+++ b/test/libsolidity/SolidityParser.cpp
@@ -73,7 +73,7 @@ bool successParse(std::string const& _source)
 }
 
 void checkFunctionNatspec(
-	ASTPointer<FunctionDefinition> _function,
+	FunctionDefinition const* _function,
 	std::string const& _expectedDoc
 )
 {
@@ -191,20 +191,18 @@ BOOST_AUTO_TEST_CASE(function_natspec_documentation)
 					   "  function functionName(bytes32 input) returns (bytes32 out) {}\n"
 					   "}\n";
 	BOOST_CHECK(successParse(text));
-	ErrorList e;
-	ASTPointer<ContractDefinition> contract = parseText(text, e);
-	ASTPointer<FunctionDefinition> function;
-
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	FunctionDefinition const* function = nullptr;
+	auto functions = contract->definedFunctions();
+
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	checkFunctionNatspec(function, "This is a test function");
 }
 
 BOOST_AUTO_TEST_CASE(function_normal_comments)
 {
-	ASTPointer<ContractDefinition> contract;
-	ASTPointer<FunctionDefinition> function;
+	FunctionDefinition const* function = nullptr;
 	char const* text = "contract test {\n"
 					   "  uint256 stateVar;\n"
 					   "  // We won't see this comment\n"
@@ -212,7 +210,8 @@ BOOST_AUTO_TEST_CASE(function_normal_comments)
 					   "}\n";
 	BOOST_CHECK(successParse(text));
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	auto functions = contract->definedFunctions();
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	BOOST_CHECK_MESSAGE(function->documentation() == nullptr,
 						"Should not have gotten a Natspecc comment for this function");
@@ -220,8 +219,7 @@ BOOST_AUTO_TEST_CASE(function_normal_comments)
 
 BOOST_AUTO_TEST_CASE(multiple_functions_natspec_documentation)
 {
-	ASTPointer<ContractDefinition> contract;
-	ASTPointer<FunctionDefinition> function;
+	FunctionDefinition const* function = nullptr;
 	char const* text = "contract test {\n"
 					   "  uint256 stateVar;\n"
 					   "  /// This is test function 1\n"
@@ -235,7 +233,8 @@ BOOST_AUTO_TEST_CASE(multiple_functions_natspec_documentation)
 					   "}\n";
 	BOOST_CHECK(successParse(text));
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	auto functions = contract->definedFunctions();
 
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	checkFunctionNatspec(function, "This is test function 1");
@@ -253,8 +252,7 @@ BOOST_AUTO_TEST_CASE(multiple_functions_natspec_documentation)
 
 BOOST_AUTO_TEST_CASE(multiline_function_documentation)
 {
-	ASTPointer<ContractDefinition> contract;
-	ASTPointer<FunctionDefinition> function;
+	FunctionDefinition const* function = nullptr;
 	char const* text = "contract test {\n"
 					   "  uint256 stateVar;\n"
 					   "  /// This is a test function\n"
@@ -263,7 +261,8 @@ BOOST_AUTO_TEST_CASE(multiline_function_documentation)
 					   "}\n";
 	BOOST_CHECK(successParse(text));
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	auto functions = contract->definedFunctions();
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	checkFunctionNatspec(function, "This is a test function\n"
 						 " and it has 2 lines");
@@ -271,8 +270,7 @@ BOOST_AUTO_TEST_CASE(multiline_function_documentation)
 
 BOOST_AUTO_TEST_CASE(natspec_comment_in_function_body)
 {
-	ASTPointer<ContractDefinition> contract;
-	ASTPointer<FunctionDefinition> function;
+	FunctionDefinition const* function = nullptr;
 	char const* text = "contract test {\n"
 					   "  /// fun1 description\n"
 					   "  function fun1(uint256 a) {\n"
@@ -288,7 +286,8 @@ BOOST_AUTO_TEST_CASE(natspec_comment_in_function_body)
 					   "}\n";
 	BOOST_CHECK(successParse(text));
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	auto functions = contract->definedFunctions();
 
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	checkFunctionNatspec(function, "fun1 description");
@@ -300,8 +299,7 @@ BOOST_AUTO_TEST_CASE(natspec_comment_in_function_body)
 
 BOOST_AUTO_TEST_CASE(natspec_docstring_between_keyword_and_signature)
 {
-	ASTPointer<ContractDefinition> contract;
-	ASTPointer<FunctionDefinition> function;
+	FunctionDefinition const* function = nullptr;
 	char const* text = "contract test {\n"
 					   "  uint256 stateVar;\n"
 					   "  function ///I am in the wrong place \n"
@@ -315,7 +313,8 @@ BOOST_AUTO_TEST_CASE(natspec_docstring_between_keyword_and_signature)
 					   "}\n";
 	BOOST_CHECK(successParse(text));
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	auto functions = contract->definedFunctions();
 
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	BOOST_CHECK_MESSAGE(!function->documentation(),
@@ -324,8 +323,7 @@ BOOST_AUTO_TEST_CASE(natspec_docstring_between_keyword_and_signature)
 
 BOOST_AUTO_TEST_CASE(natspec_docstring_after_signature)
 {
-	ASTPointer<ContractDefinition> contract;
-	ASTPointer<FunctionDefinition> function;
+	FunctionDefinition const* function = nullptr;
 	char const* text = "contract test {\n"
 					   "  uint256 stateVar;\n"
 					   "  function fun1(uint256 a) {\n"
@@ -339,7 +337,8 @@ BOOST_AUTO_TEST_CASE(natspec_docstring_after_signature)
 					   "}\n";
 	BOOST_CHECK(successParse(text));
 	ErrorList errors;
-	auto functions = parseText(text, errors)->definedFunctions();
+	ASTPointer<ContractDefinition> contract = parseText(text, errors);
+	auto functions = contract->definedFunctions();
 
 	ETH_TEST_REQUIRE_NO_THROW(function = functions.at(0), "Failed to retrieve function");
 	BOOST_CHECK_MESSAGE(!function->documentation(),