Parsing of not fully implemented functions

- Adding the possibility of omitting a function body by simply ending a
  function definition with a semicolon

- Such a function is marked as not fully implemented and any contract
  that contains such a function is considered a not fully implemented contract

libsolidity/AST.cpp

@@ -311,7 +311,7 @@ void FunctionDefinition::checkTypeRequirements()
 		modifier->checkTypeRequirements(isConstructor() ?
 			dynamic_cast<ContractDefinition const&>(*getScope()).getBaseContracts() :
 			vector<ASTPointer<InheritanceSpecifier>>());
-
+	if (m_body)
 		m_body->checkTypeRequirements();
 }
 

libsolidity/AST.h

@@ -196,6 +196,21 @@ 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; }
+
+protected:
+	bool m_implemented;
+};
+
 /// @}
 
 /**
@@ -203,10 +218,11 @@ 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 +231,12 @@ 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):
-		Declaration(_location, _name), Documented(_documentation),
+		std::vector<ASTPointer<EventDefinition>> const& _events,
+		bool _isFullyImplemented
+	):
+		Declaration(_location, _name),
+		Documented(_documentation),
+		ImplementationOptional(_isFullyImplemented),
 		m_baseContracts(_baseContracts),
 		m_definedStructs(_definedStructs),
 		m_definedEnums(_definedEnums),
@@ -378,18 +398,23 @@ 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):
-	Declaration(_location, _name, _visibility), Documented(_documentation),
+		ASTPointer<Block> const& _body
+	):
+		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/Parser.cpp

@@ -116,6 +116,7 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition()
 {
 	ASTNodeFactory nodeFactory(*this);
 	ASTPointer<ASTString> docString;
+	bool contractFullyImplemented = true;
 	if (m_scanner->getCurrentCommentLiteral() != "")
 		docString = make_shared<ASTString>(m_scanner->getCurrentCommentLiteral());
 	expectToken(Token::Contract);
@@ -141,7 +142,12 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition()
 		if (currentToken == Token::RBrace)
 			break;
 		else if (currentToken == Token::Function)
-			functions.push_back(parseFunctionDefinition(name.get()));
+		{
+			ASTPointer<FunctionDefinition> func = parseFunctionDefinition(name.get());
+			functions.push_back(func);
+			if (!func->isFullyImplemented())
+				contractFullyImplemented = false;
+		}
 		else if (currentToken == Token::Struct)
 			structs.push_back(parseStructDefinition());
 		else if (currentToken == Token::Enum)
@@ -164,8 +170,18 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition()
 	}
 	nodeFactory.markEndPosition();
 	expectToken(Token::RBrace);
-	return nodeFactory.createNode<ContractDefinition>(name, docString, baseContracts, structs, enums,
-													  stateVariables, functions, modifiers, events);
+	return nodeFactory.createNode<ContractDefinition>(
+		name,
+		docString,
+		baseContracts,
+		structs,
+		enums,
+		stateVariables,
+		functions,
+		modifiers,
+		events,
+		contractFullyImplemented
+	);
 }
 
 ASTPointer<InheritanceSpecifier> Parser::parseInheritanceSpecifier()
@@ -247,8 +263,15 @@ 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

@@ -346,6 +346,21 @@ 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");
+	ContractDefinition* contract;
+	for (ASTPointer<ASTNode> const& node: sourceUnit->getNodes())
+		contract = dynamic_cast<ContractDefinition*>(node.get());
+	BOOST_CHECK(contract);
+	BOOST_CHECK(!contract->isFullyImplemented());
+	BOOST_CHECK(!contract->getDefinedFunctions()[0]->isFullyImplemented());
+}
+
 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"