Blocks and for loops can be scopes.

libsolidity/analysis/NameAndTypeResolver.cpp

@@ -610,6 +610,30 @@ void DeclarationRegistrationHelper::endVisit(ModifierDefinition&)
 	closeCurrentScope();
 }
 
+bool DeclarationRegistrationHelper::visit(Block& _block)
+{
+	enterNewSubScope(_block);
+	return true;
+}
+
+void DeclarationRegistrationHelper::endVisit(Block&)
+{
+	closeCurrentScope();
+}
+
+bool DeclarationRegistrationHelper::visit(ForStatement& _for)
+{
+	// TODO special scoping rules for the init statement - if it is a block, then it should
+	// not open its own scope.
+	enterNewSubScope(_for);
+	return true;
+}
+
+void DeclarationRegistrationHelper::endVisit(ForStatement&)
+{
+	closeCurrentScope();
+}
+
 void DeclarationRegistrationHelper::endVisit(VariableDeclarationStatement& _variableDeclarationStatement)
 {
 	// Register the local variables with the function

libsolidity/analysis/NameAndTypeResolver.h

@@ -167,6 +167,10 @@ private:
 	void endVisit(FunctionDefinition& _function) override;
 	bool visit(ModifierDefinition& _modifier) override;
 	void endVisit(ModifierDefinition& _modifier) override;
+	bool visit(Block& _block) override;
+	void endVisit(Block& _block) override;
+	bool visit(ForStatement& _forLoop) override;
+	void endVisit(ForStatement& _forLoop) override;
 	void endVisit(VariableDeclarationStatement& _variableDeclarationStatement) override;
 	bool visit(VariableDeclaration& _declaration) override;
 	bool visit(EventDefinition& _event) override;

libsolidity/analysis/ReferencesResolver.cpp

@@ -43,6 +43,37 @@ bool ReferencesResolver::resolve(ASTNode const& _root)
 	return !m_errorOccurred;
 }
 
+bool ReferencesResolver::visit(Block const& _block)
+{
+	if (!m_resolveInsideCode)
+		return false;
+	m_resolver.setScope(&_block);
+	return true;
+}
+
+void ReferencesResolver::endVisit(Block const& _block)
+{
+	if (!m_resolveInsideCode)
+		return;
+
+	m_resolver.setScope(_block.scope());
+}
+
+bool ReferencesResolver::visit(ForStatement const& _for)
+{
+	if (!m_resolveInsideCode)
+		return false;
+	m_resolver.setScope(&_for);
+	return true;
+}
+
+void ReferencesResolver::endVisit(ForStatement const& _for)
+{
+	if (!m_resolveInsideCode)
+		return;
+	m_resolver.setScope(_for.scope());
+}
+
 bool ReferencesResolver::visit(Identifier const& _identifier)
 {
 	auto declarations = m_resolver.nameFromCurrentScope(_identifier.name());

libsolidity/analysis/ReferencesResolver.h

@@ -57,7 +57,10 @@ public:
 	bool resolve(ASTNode const& _root);
 
 private:
-	virtual bool visit(Block const&) override { return m_resolveInsideCode; }
+	virtual bool visit(Block const& _block) override;
+	virtual void endVisit(Block const& _block) override;
+	virtual bool visit(ForStatement const& _for) override;
+	virtual void endVisit(ForStatement const& _for) override;
 	virtual bool visit(Identifier const& _identifier) override;
 	virtual bool visit(ElementaryTypeName const& _typeName) override;
 	virtual bool visit(FunctionDefinition const& _functionDefinition) override;

libsolidity/ast/AST.cpp

@@ -415,6 +415,15 @@ bool VariableDeclaration::isLValue() const
 	return !isExternalCallableParameter() && !m_isConstant;
 }
 
+bool VariableDeclaration::isLocalVariable() const
+{
+	auto s = scope();
+	return
+		dynamic_cast<CallableDeclaration const*>(s) ||
+		dynamic_cast<Block const*>(s) ||
+		dynamic_cast<ForStatement const*>(s);
+}
+
 bool VariableDeclaration::isCallableParameter() const
 {
 	auto const* callable = dynamic_cast<CallableDeclaration const*>(scope());
@@ -460,8 +469,7 @@ bool VariableDeclaration::isExternalCallableParameter() const
 
 bool VariableDeclaration::canHaveAutoType() const
 {
-	auto const* callable = dynamic_cast<CallableDeclaration const*>(scope());
-	return (!!callable && !isCallableParameter());
+	return isLocalVariable() && !isCallableParameter();
 }
 
 TypePointer VariableDeclaration::type() const

libsolidity/ast/AST.h

@@ -299,6 +299,8 @@ private:
 
 /**
  * Abstract class that is added to each AST node that can store local variables.
+ * Local variables in functions are always added to functions, even though they are not
+ * in scope for the whole function.
  */
 class VariableScope
 {
@@ -672,7 +674,7 @@ public:
 	virtual bool isLValue() const override;
 	virtual bool isPartOfExternalInterface() const override { return isPublic(); }
 
-	bool isLocalVariable() const { return !!dynamic_cast<CallableDeclaration const*>(scope()); }
+	bool isLocalVariable() const;
 	/// @returns true if this variable is a parameter or return parameter of a function.
 	bool isCallableParameter() const;
 	/// @returns true if this variable is a return parameter of a function.
@@ -1014,7 +1016,7 @@ private:
 /**
  * Brace-enclosed block containing zero or more statements.
  */
-class Block: public Statement
+class Block: public Statement, public Scopable
 {
 public:
 	Block(
@@ -1121,7 +1123,7 @@ private:
 /**
  * For loop statement
  */
-class ForStatement: public BreakableStatement
+class ForStatement: public BreakableStatement, public Scopable
 {
 public:
 	ForStatement(