Scopes do not have to be declarations.

libsolidity/analysis/NameAndTypeResolver.cpp

@@ -244,19 +244,24 @@ void NameAndTypeResolver::warnVariablesNamedLikeInstructions()
 	}
 }
 
+void NameAndTypeResolver::setScope(ASTNode const* _node)
+{
+	m_currentScope = m_scopes[_node].get();
+}
+
 bool NameAndTypeResolver::resolveNamesAndTypesInternal(ASTNode& _node, bool _resolveInsideCode)
 {
 	if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(&_node))
 	{
 		bool success = true;
-		m_currentScope = m_scopes[contract->scope()].get();
+		setScope(contract->scope());
 		solAssert(!!m_currentScope, "");
 
 		for (ASTPointer<InheritanceSpecifier> const& baseContract: contract->baseContracts())
 			if (!resolveNamesAndTypes(*baseContract, true))
 				success = false;
 
-		m_currentScope = m_scopes[contract].get();
+		setScope(contract);
 
 		if (success)
 		{
@@ -273,7 +278,7 @@ bool NameAndTypeResolver::resolveNamesAndTypesInternal(ASTNode& _node, bool _res
 		// these can contain code, only resolve parameters for now
 		for (ASTPointer<ASTNode> const& node: contract->subNodes())
 		{
-			m_currentScope = m_scopes[contract].get();
+			setScope(contract);
 			if (!resolveNamesAndTypes(*node, false))
 			{
 				success = false;
@@ -287,12 +292,12 @@ bool NameAndTypeResolver::resolveNamesAndTypesInternal(ASTNode& _node, bool _res
 		if (!_resolveInsideCode)
 			return success;
 
-		m_currentScope = m_scopes[contract].get();
+		setScope(contract);
 
 		// now resolve references inside the code
 		for (ASTPointer<ASTNode> const& node: contract->subNodes())
 		{
-			m_currentScope = m_scopes[contract].get();
+			setScope(contract);
 			if (!resolveNamesAndTypes(*node, true))
 				success = false;
 		}
@@ -301,7 +306,7 @@ bool NameAndTypeResolver::resolveNamesAndTypesInternal(ASTNode& _node, bool _res
 	else
 	{
 		if (m_scopes.count(&_node))
-			m_currentScope = m_scopes[&_node].get();
+			setScope(&_node);
 		return ReferencesResolver(m_errorReporter, *this, _resolveInsideCode).resolve(_node);
 	}
 }
@@ -632,14 +637,17 @@ void DeclarationRegistrationHelper::endVisit(EventDefinition&)
 	closeCurrentScope();
 }
 
-void DeclarationRegistrationHelper::enterNewSubScope(Declaration const& _declaration)
+void DeclarationRegistrationHelper::enterNewSubScope(ASTNode& _subScope)
 {
+	if (auto s = dynamic_cast<Scopable*>(&_subScope))
+		s->setScope(m_currentScope);
+
 	map<ASTNode const*, shared_ptr<DeclarationContainer>>::iterator iter;
 	bool newlyAdded;
 	shared_ptr<DeclarationContainer> container(new DeclarationContainer(m_currentScope, m_scopes[m_currentScope].get()));
-	tie(iter, newlyAdded) = m_scopes.emplace(&_declaration, move(container));
+	tie(iter, newlyAdded) = m_scopes.emplace(&_subScope, move(container));
 	solAssert(newlyAdded, "Unable to add new scope.");
-	m_currentScope = &_declaration;
+	m_currentScope = &_subScope;
 }
 
 void DeclarationRegistrationHelper::closeCurrentScope()
@@ -669,9 +677,10 @@ void DeclarationRegistrationHelper::registerDeclaration(Declaration& _declaratio
 
 	registerDeclaration(*m_scopes[m_currentScope], _declaration, nullptr, nullptr, warnAboutShadowing, m_errorReporter);
 
-	_declaration.setScope(m_currentScope);
 	if (_opensScope)
 		enterNewSubScope(_declaration);
+	else
+		_declaration.setScope(m_currentScope);
 }
 
 string DeclarationRegistrationHelper::currentCanonicalName() const

libsolidity/analysis/NameAndTypeResolver.h

@@ -97,6 +97,9 @@ public:
 	/// @returns a list of similar identifiers in the current and enclosing scopes. May return empty string if no suggestions.
 	std::string similarNameSuggestions(ASTString const& _name) const;
 
+	/// Sets the current scope.
+	void setScope(ASTNode const* _node);
+
 private:
 	/// Internal version of @a resolveNamesAndTypes (called from there) throws exceptions on fatal errors.
 	bool resolveNamesAndTypesInternal(ASTNode& _node, bool _resolveInsideCode = true);
@@ -169,7 +172,7 @@ private:
 	bool visit(EventDefinition& _event) override;
 	void endVisit(EventDefinition& _event) override;
 
-	void enterNewSubScope(Declaration const& _declaration);
+	void enterNewSubScope(ASTNode& _subScope);
 	void closeCurrentScope();
 	void registerDeclaration(Declaration& _declaration, bool _opensScope);
 

libsolidity/ast/AST.cpp

@@ -98,11 +98,12 @@ set<SourceUnit const*> SourceUnit::referencedSourceUnits(bool _recurse, set<Sour
 
 SourceUnit const& Declaration::sourceUnit() const
 {
-	solAssert(!!m_scope, "");
+	ASTNode const* s = scope();
-	ASTNode const* scope = m_scope;
+	solAssert(s, "");
-	while (dynamic_cast<Declaration const*>(scope) && dynamic_cast<Declaration const*>(scope)->m_scope)
+	// will not always be a declaratoion
-		scope = dynamic_cast<Declaration const*>(scope)->m_scope;
+	while (dynamic_cast<Scopable const*>(s) && dynamic_cast<Scopable const*>(s)->scope())
-	return dynamic_cast<SourceUnit const&>(*scope);
+		s = dynamic_cast<Scopable const*>(s)->scope();
+	return dynamic_cast<SourceUnit const&>(*s);
 }
 
 string Declaration::sourceUnitName() const

libsolidity/ast/AST.h

@@ -139,10 +139,26 @@ private:
 	std::vector<ASTPointer<ASTNode>> m_nodes;
 };
 
+/**
+ * Abstract class that is added to each AST node that is stored inside a scope
+ * (including scopes).
+ */
+class Scopable
+{
+public:
+	/// @returns the scope this declaration resides in. Can be nullptr if it is the global scope.
+	/// Available only after name and type resolution step.
+	ASTNode const* scope() const { return m_scope; }
+	void setScope(ASTNode const* _scope) { m_scope = _scope; }
+
+protected:
+	ASTNode const* m_scope = nullptr;
+};
+
 /**
  * Abstract AST class for a declaration (contract, function, struct, variable, import directive).
  */
-class Declaration: public ASTNode
+class Declaration: public ASTNode, public Scopable
 {
 public:
 	/// Visibility ordered from restricted to unrestricted.
@@ -171,7 +187,7 @@ public:
 		ASTPointer<ASTString> const& _name,
 		Visibility _visibility = Visibility::Default
 	):
-		ASTNode(_location), m_name(_name), m_visibility(_visibility), m_scope(nullptr) {}
+		ASTNode(_location), m_name(_name), m_visibility(_visibility) {}
 
 	/// @returns the declared name.
 	ASTString const& name() const { return *m_name; }
@@ -181,11 +197,6 @@ public:
 	virtual bool isVisibleInContract() const { return visibility() != Visibility::External; }
 	bool isVisibleInDerivedContracts() const { return isVisibleInContract() && visibility() >= Visibility::Internal; }
 
-	/// @returns the scope this declaration resides in. Can be nullptr if it is the global scope.
-	/// Available only after name and type resolution step.
-	ASTNode const* scope() const { return m_scope; }
-	void setScope(ASTNode const* _scope) { m_scope = _scope; }
-
 	/// @returns the source unit this declaration is present in.
 	SourceUnit const& sourceUnit() const;
 
@@ -213,7 +224,6 @@ protected:
 private:
 	ASTPointer<ASTString> m_name;
 	Visibility m_visibility;
-	ASTNode const* m_scope;
 };
 
 /**