Merge pull request #1414 from LefterisJP/sol_notImplementedFuncs

Interface contracts

libsolidity/AST.cpp

@@ -21,6 +21,7 @@
  */
 
 #include <algorithm>
+#include <boost/range/adaptor/reversed.hpp>
 #include <libsolidity/Utils.h>
 #include <libsolidity/AST.h>
 #include <libsolidity/ASTVisitor.h>
@@ -52,6 +53,7 @@ void ContractDefinition::checkTypeRequirements()
 		baseSpecifier->checkTypeRequirements();
 
 	checkIllegalOverrides();
+	checkAbstractFunctions();
 
 	FunctionDefinition const* constructor = getConstructor();
 	if (constructor && !constructor->getReturnParameters().empty())
@@ -60,6 +62,7 @@ void ContractDefinition::checkTypeRequirements()
 
 	FunctionDefinition const* fallbackFunction = nullptr;
 	for (ASTPointer<FunctionDefinition> const& function: getDefinedFunctions())
+	{
 		if (function->getName().empty())
 		{
 			if (fallbackFunction)
@@ -71,6 +74,9 @@ void ContractDefinition::checkTypeRequirements()
 					BOOST_THROW_EXCEPTION(fallbackFunction->getParameterList().createTypeError("Fallback function cannot take parameters."));
 			}
 		}
+		if (!function->isFullyImplemented())
+			setFullyImplemented(false);
+	}
 	for (ASTPointer<ModifierDefinition> const& modifier: getFunctionModifiers())
 		modifier->checkTypeRequirements();
 
@@ -124,6 +130,28 @@ FunctionDefinition const* ContractDefinition::getFallbackFunction() const
 	return nullptr;
 }
 
+void ContractDefinition::checkAbstractFunctions()
+{
+	map<string, bool> functions;
+
+	// Search from base to derived
+	for (ContractDefinition const* contract: boost::adaptors::reverse(getLinearizedBaseContracts()))
+		for (ASTPointer<FunctionDefinition> const& function: contract->getDefinedFunctions())
+		{
+			string const& name = function->getName();
+			if (!function->isFullyImplemented() && functions.count(name) && functions[name])
+				BOOST_THROW_EXCEPTION(function->createTypeError("Redeclaring an already implemented function as abstract"));
+			functions[name] = function->isFullyImplemented();
+		}
+
+	for (auto const& it: functions)
+		if (!it.second)
+		{
+			setFullyImplemented(false);
+			break;
+		}
+}
+
 void ContractDefinition::checkIllegalOverrides() const
 {
 	// TODO unify this at a later point. for this we need to put the constness and the access specifier
@@ -316,7 +344,7 @@ void FunctionDefinition::checkTypeRequirements()
 		modifier->checkTypeRequirements(isConstructor() ?
 			dynamic_cast<ContractDefinition const&>(*getScope()).getBaseContracts() :
 			vector<ASTPointer<InheritanceSpecifier>>());
-
+	if (m_body)
 		m_body->checkTypeRequirements();
 }
 
@@ -649,6 +677,8 @@ void NewExpression::checkTypeRequirements()
 	m_contract = dynamic_cast<ContractDefinition const*>(m_contractName->getReferencedDeclaration());
 	if (!m_contract)
 		BOOST_THROW_EXCEPTION(createTypeError("Identifier is not a contract."));
+	if (!m_contract->isFullyImplemented())
+		BOOST_THROW_EXCEPTION(m_contract->createTypeError("Trying to create an instance of an abstract contract."));
 	shared_ptr<ContractType const> contractType = make_shared<ContractType>(*m_contract);
 	TypePointers const& parameterTypes = contractType->getConstructorType()->getParameterTypes();
 	m_type = make_shared<FunctionType>(parameterTypes, TypePointers{contractType},

libsolidity/AST.h

@@ -196,6 +196,22 @@ protected:
 	ASTPointer<ASTString> m_documentation;
 };
 
+/**
+ * Abstract class that is added to AST nodes that can be marked as not being fully implemented
+ */
+class ImplementationOptional
+{
+public:
+	explicit ImplementationOptional(bool _implemented): m_implemented(_implemented) {}
+
+	/// @return whether this node is fully implemented or not
+	bool isFullyImplemented() const { return m_implemented; }
+	void setFullyImplemented(bool _implemented) {  m_implemented = _implemented; }
+
+protected:
+	bool m_implemented;
+};
+
 /// @}
 
 /**
@@ -203,10 +219,11 @@ protected:
  * document order. It first visits all struct declarations, then all variable declarations and
  * finally all function declarations.
  */
-class ContractDefinition: public Declaration, public Documented
+class ContractDefinition: public Declaration, public Documented, public ImplementationOptional
 {
 public:
-	ContractDefinition(SourceLocation const& _location,
+	ContractDefinition(
+		SourceLocation const& _location,
 		ASTPointer<ASTString> const& _name,
 		ASTPointer<ASTString> const& _documentation,
 		std::vector<ASTPointer<InheritanceSpecifier>> const& _baseContracts,
@@ -215,8 +232,11 @@ public:
 		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<EventDefinition>> const& _events
-		Declaration(_location, _name), Documented(_documentation),
+	):
+		Declaration(_location, _name),
+		Documented(_documentation),
+		ImplementationOptional(true),
 		m_baseContracts(_baseContracts),
 		m_definedStructs(_definedStructs),
 		m_definedEnums(_definedEnums),
@@ -263,6 +283,7 @@ public:
 
 private:
 	void checkIllegalOverrides() const;
+	void checkAbstractFunctions();
 
 	std::vector<std::pair<FixedHash<4>, FunctionTypePointer>> const& getInterfaceFunctionList() const;
 
@@ -378,18 +399,23 @@ private:
 	std::vector<ASTPointer<VariableDeclaration>> m_parameters;
 };
 
-class FunctionDefinition: public Declaration, public VariableScope, public Documented
+class FunctionDefinition: public Declaration, public VariableScope, public Documented, public ImplementationOptional
 {
 public:
-	FunctionDefinition(SourceLocation const& _location, ASTPointer<ASTString> const& _name,
+	FunctionDefinition(
+		SourceLocation const& _location,
+		ASTPointer<ASTString> const& _name,
 		Declaration::Visibility _visibility, bool _isConstructor,
 		ASTPointer<ASTString> const& _documentation,
 		ASTPointer<ParameterList> const& _parameters,
 		bool _isDeclaredConst,
 		std::vector<ASTPointer<ModifierInvocation>> const& _modifiers,
 		ASTPointer<ParameterList> const& _returnParameters,
-					ASTPointer<Block> const& _body):
+		ASTPointer<Block> const& _body
-	Declaration(_location, _name, _visibility), Documented(_documentation),
+	):
+		Declaration(_location, _name, _visibility),
+		Documented(_documentation),
+		ImplementationOptional(_body != nullptr),
 		m_isConstructor(_isConstructor),
 		m_parameters(_parameters),
 		m_isDeclaredConst(_isDeclaredConst),

libsolidity/AST_accept.h

@@ -175,6 +175,7 @@ void FunctionDefinition::accept(ASTVisitor& _visitor)
 		if (m_returnParameters)
 			m_returnParameters->accept(_visitor);
 		listAccept(m_functionModifiers, _visitor);
+		if (m_body)
 			m_body->accept(_visitor);
 	}
 	_visitor.endVisit(*this);
@@ -188,6 +189,7 @@ void FunctionDefinition::accept(ASTConstVisitor& _visitor) const
 		if (m_returnParameters)
 			m_returnParameters->accept(_visitor);
 		listAccept(m_functionModifiers, _visitor);
+		if (m_body)
 			m_body->accept(_visitor);
 	}
 	_visitor.endVisit(*this);

libsolidity/CompilerStack.cpp

@@ -138,6 +138,8 @@ void CompilerStack::compile(bool _optimize)
 		for (ASTPointer<ASTNode> const& node: source->ast->getNodes())
 			if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
 			{
+				if (!contract->isFullyImplemented())
+					continue;
 				shared_ptr<Compiler> compiler = make_shared<Compiler>(_optimize);
 				compiler->compileContract(*contract, contractBytecode);
 				Contract& compiledContract = m_contracts[contract->getName()];

libsolidity/Parser.cpp

@@ -164,8 +164,17 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition()
 	}
 	nodeFactory.markEndPosition();
 	expectToken(Token::RBrace);
-	return nodeFactory.createNode<ContractDefinition>(name, docString, baseContracts, structs, enums,
+	return nodeFactory.createNode<ContractDefinition>(
-													  stateVariables, functions, modifiers, events);
+		name,
+		docString,
+		baseContracts,
+		structs,
+		enums,
+		stateVariables,
+		functions,
+		modifiers,
+		events
+	);
 }
 
 ASTPointer<InheritanceSpecifier> Parser::parseInheritanceSpecifier()
@@ -247,8 +256,15 @@ ASTPointer<FunctionDefinition> Parser::parseFunctionDefinition(ASTString const*
 	}
 	else
 		returnParameters = createEmptyParameterList();
-	ASTPointer<Block> block = parseBlock();
+	ASTPointer<Block> block = ASTPointer<Block>();
+	nodeFactory.markEndPosition();
+	if (m_scanner->getCurrentToken() != Token::Semicolon)
+	{
+		block = parseBlock();
 		nodeFactory.setEndPositionFromNode(block);
+	}
+	else
+		m_scanner->next(); // just consume the ';'
 	bool const c_isConstructor = (_contractName && *name == *_contractName);
 	return nodeFactory.createNode<FunctionDefinition>(name, visibility, c_isConstructor, docstring,
 													  parameters, isDeclaredConst, modifiers,

test/SolidityNameAndTypeResolution.cpp

@@ -359,6 +359,63 @@ BOOST_AUTO_TEST_CASE(comparison_bitop_precedence)
 	ETH_TEST_CHECK_NO_THROW(parseTextAndResolveNames(text), "Parsing and Name Resolving Failed");
 }
 
+BOOST_AUTO_TEST_CASE(function_no_implementation)
+{
+	ASTPointer<SourceUnit> sourceUnit;
+	char const* text = "contract test {\n"
+		"  function functionName(bytes32 input) returns (bytes32 out);\n"
+		"}\n";
+	ETH_TEST_REQUIRE_NO_THROW(sourceUnit = parseTextAndResolveNames(text), "Parsing and name Resolving failed");
+	std::vector<ASTPointer<ASTNode>> nodes = sourceUnit->getNodes();
+	ContractDefinition* contract = dynamic_cast<ContractDefinition*>(nodes[0].get());
+	BOOST_CHECK(contract);
+	BOOST_CHECK(!contract->isFullyImplemented());
+	BOOST_CHECK(!contract->getDefinedFunctions()[0]->isFullyImplemented());
+}
+
+BOOST_AUTO_TEST_CASE(abstract_contract)
+{
+	ASTPointer<SourceUnit> sourceUnit;
+	char const* text = R"(
+		contract base { function foo(); }
+		contract derived is base { function foo() {} }
+		)";
+	ETH_TEST_REQUIRE_NO_THROW(sourceUnit = parseTextAndResolveNames(text), "Parsing and name Resolving failed");
+	std::vector<ASTPointer<ASTNode>> nodes = sourceUnit->getNodes();
+	ContractDefinition* base = dynamic_cast<ContractDefinition*>(nodes[0].get());
+	ContractDefinition* derived = dynamic_cast<ContractDefinition*>(nodes[1].get());
+	BOOST_CHECK(base);
+	BOOST_CHECK(!base->isFullyImplemented());
+	BOOST_CHECK(!base->getDefinedFunctions()[0]->isFullyImplemented());
+	BOOST_CHECK(derived);
+	BOOST_CHECK(derived->isFullyImplemented());
+	BOOST_CHECK(derived->getDefinedFunctions()[0]->isFullyImplemented());
+}
+
+BOOST_AUTO_TEST_CASE(create_abstract_contract)
+{
+	ASTPointer<SourceUnit> sourceUnit;
+	char const* text = R"(
+		contract base { function foo(); }
+		contract derived {
+			base b;
+			function foo() { b = new base();}
+			}
+		)";
+	BOOST_CHECK_THROW(parseTextAndResolveNames(text), TypeError);
+}
+
+BOOST_AUTO_TEST_CASE(redeclare_implemented_abstract_function_as_abstract)
+{
+	ASTPointer<SourceUnit> sourceUnit;
+	char const* text = R"(
+		contract base { function foo(); }
+		contract derived is base { function foo() {} }
+		contract wrong is derived { function foo(); }
+		)";
+	BOOST_CHECK_THROW(parseTextAndResolveNames(text), TypeError);
+}
+
 BOOST_AUTO_TEST_CASE(function_canonical_signature)
 {
 	ASTPointer<SourceUnit> sourceUnit;

test/SolidityParser.cpp

@@ -108,6 +108,14 @@ BOOST_AUTO_TEST_CASE(single_function_param)
 	ETH_TEST_CHECK_NO_THROW(parseText(text), "Parsing failed.");
 }
 
+BOOST_AUTO_TEST_CASE(function_no_body)
+{
+	char const* text = "contract test {\n"
+					   "  function functionName(bytes32 input) returns (bytes32 out);\n"
+					   "}\n";
+	ETH_TEST_CHECK_NO_THROW(parseText(text), "Parsing failed.");
+}
+
 BOOST_AUTO_TEST_CASE(missing_parameter_name_in_named_args)
 {
 	char const* text = "contract test {\n"