Merge pull request #66 from chriseth/sol_libraries

Calling libraries.

15 files changed, 159 insertions, 87 deletions

diff --git a/libsolidity/AST.cpp b/libsolidity/AST.cpp
index 1ad34cfe..674f33b7 100644
--- a/libsolidity/AST.cpp
+++ b/libsolidity/AST.cpp
@@ -106,6 +106,9 @@ void ContractDefinition::checkTypeRequirements()
 			));
 		hashes.insert(hash);
 	}
+
+	if (isLibrary())
+		checkLibraryRequirements();
 }
 
 map<FixedHash<4>, FunctionTypePointer> ContractDefinition::interfaceFunctions() const
@@ -335,6 +338,17 @@ void ContractDefinition::checkExternalTypeClashes() const
 					));
 }
 
+void ContractDefinition::checkLibraryRequirements() const
+{
+	solAssert(m_isLibrary, "");
+	if (!m_baseContracts.empty())
+		BOOST_THROW_EXCEPTION(createTypeError("Library is not allowed to inherit."));
+
+	for (auto const& var: m_stateVariables)
+		if (!var->isConstant())
+			BOOST_THROW_EXCEPTION(var->createTypeError("Library cannot have non-constant state variables"));
+}
+
 vector<ASTPointer<EventDefinition>> const& ContractDefinition::interfaceEvents() const
 {
 	if (!m_interfaceEvents)
@@ -452,6 +466,10 @@ void InheritanceSpecifier::checkTypeRequirements()
 
 	ContractDefinition const* base = dynamic_cast<ContractDefinition const*>(&m_baseName->referencedDeclaration());
 	solAssert(base, "Base contract not available.");
+
+	if (base->isLibrary())
+		BOOST_THROW_EXCEPTION(createTypeError("Libraries cannot be inherited from."));
+
 	TypePointers parameterTypes = ContractType(*base).constructorType()->parameterTypes();
 	if (!m_arguments.empty() && parameterTypes.size() != m_arguments.size())
 		BOOST_THROW_EXCEPTION(createTypeError(
diff --git a/libsolidity/AST.h b/libsolidity/AST.h
index 48790e6a..da6a7d58 100644
--- a/libsolidity/AST.h
+++ b/libsolidity/AST.h
@@ -215,7 +215,7 @@ protected:
 /// @}
 
 /**
- * Definition of a contract. This is the only AST nodes where child nodes are not visited in
+ * Definition of a contract or library. This is the only AST nodes where child nodes are not visited in
  * document order. It first visits all struct declarations, then all variable declarations and
  * finally all function declarations.
  */
@@ -232,7 +232,8 @@ 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,
+		bool _isLibrary
 	):
 		Declaration(_location, _name),
 		Documented(_documentation),
@@ -243,7 +244,8 @@ public:
 		m_stateVariables(_stateVariables),
 		m_definedFunctions(_definedFunctions),
 		m_functionModifiers(_functionModifiers),
-		m_events(_events)
+		m_events(_events),
+		m_isLibrary(_isLibrary)
 	{}
 
 	virtual void accept(ASTVisitor& _visitor) override;
@@ -257,6 +259,7 @@ public:
 	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;
+	bool isLibrary() const { return m_isLibrary; }
 
 	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
 
@@ -297,6 +300,8 @@ private:
 	/// Checks that different functions with external visibility end up having different
 	/// external argument types (i.e. different signature).
 	void checkExternalTypeClashes() const;
+	/// Checks that all requirements for a library are fulfilled if this is a library.
+	void checkLibraryRequirements() const;
 
 	std::vector<std::pair<FixedHash<4>, FunctionTypePointer>> const& interfaceFunctionList() const;
 
@@ -307,6 +312,7 @@ private:
 	std::vector<ASTPointer<FunctionDefinition>> m_definedFunctions;
 	std::vector<ASTPointer<ModifierDefinition>> m_functionModifiers;
 	std::vector<ASTPointer<EventDefinition>> m_events;
+	bool m_isLibrary;
 
 	// parsed Natspec documentation of the contract.
 	std::string m_userDocumentation;
diff --git a/libsolidity/Compiler.cpp b/libsolidity/Compiler.cpp
index 8394efa3..9bdf45f8 100644
--- a/libsolidity/Compiler.cpp
+++ b/libsolidity/Compiler.cpp
@@ -48,8 +48,10 @@ private:
 	unsigned stackHeight;
 };
 
-void Compiler::compileContract(ContractDefinition const& _contract,
-							   map<ContractDefinition const*, bytes const*> const& _contracts)
+void Compiler::compileContract(
+	ContractDefinition const& _contract,
+	std::map<const ContractDefinition*, eth::Assembly const*> const& _contracts
+)
 {
 	m_context = CompilerContext(); // clear it just in case
 	{
@@ -70,7 +72,7 @@ void Compiler::compileContract(ContractDefinition const& _contract,
 
 void Compiler::compileClone(
 	ContractDefinition const& _contract,
-	map<ContractDefinition const*, bytes const*> const& _contracts
+	map<ContractDefinition const*, eth::Assembly const*> const& _contracts
 )
 {
 	m_context = CompilerContext(); // clear it just in case
@@ -98,11 +100,13 @@ eth::AssemblyItem Compiler::functionEntryLabel(FunctionDefinition const& _functi
 	return m_runtimeContext.functionEntryLabelIfExists(_function);
 }
 
-void Compiler::initializeContext(ContractDefinition const& _contract,
-								 map<ContractDefinition const*, bytes const*> const& _contracts)
+void Compiler::initializeContext(
+	ContractDefinition const& _contract,
+	map<ContractDefinition const*, eth::Assembly const*> const& _compiledContracts
+)
 {
 	CompilerUtils(m_context).initialiseFreeMemoryPointer();
-	m_context.setCompiledContracts(_contracts);
+	m_context.setCompiledContracts(_compiledContracts);
 	m_context.setInheritanceHierarchy(_contract.linearizedBaseContracts());
 	registerStateVariables(_contract);
 	m_context.resetVisitedNodes(&_contract);
diff --git a/libsolidity/Compiler.h b/libsolidity/Compiler.h
index f283683f..7e1d3222 100644
--- a/libsolidity/Compiler.h
+++ b/libsolidity/Compiler.h
@@ -42,16 +42,19 @@ public:
 	{
 	}
 
-	void compileContract(ContractDefinition const& _contract,
-						 std::map<ContractDefinition const*, bytes const*> const& _contracts);
+	void compileContract(
+		ContractDefinition const& _contract,
+		std::map<ContractDefinition const*, eth::Assembly const*> const& _contracts
+	);
 	/// Compiles a contract that uses CALLCODE to call into a pre-deployed version of the given
 	/// contract at runtime, but contains the full creation-time code.
 	void compileClone(
 		ContractDefinition const& _contract,
-		std::map<ContractDefinition const*, bytes const*> const& _contracts
+		std::map<ContractDefinition const*, eth::Assembly const*> const& _contracts
 	);
-	bytes assembledBytecode() { return m_context.assembledBytecode(); }
-	bytes runtimeBytecode() { return m_context.assembledRuntimeBytecode(m_runtimeSub); }
+	eth::Assembly const& assembly() { return m_context.assembly(); }
+	eth::LinkerObject assembledObject() { return m_context.assembledObject(); }
+	eth::LinkerObject runtimeObject() { return m_context.assembledRuntimeObject(m_runtimeSub); }
 	/// @arg _sourceCodes is the map of input files to source code strings
 	/// @arg _inJsonFromat shows whether the out should be in Json format
 	Json::Value streamAssembly(std::ostream& _stream, StringMap const& _sourceCodes = StringMap(), bool _inJsonFormat = false) const
@@ -69,8 +72,10 @@ public:
 
 private:
 	/// Registers the non-function objects inside the contract with the context.
-	void initializeContext(ContractDefinition const& _contract,
-						   std::map<ContractDefinition const*, bytes const*> const& _contracts);
+	void initializeContext(
+		ContractDefinition const& _contract,
+		std::map<ContractDefinition const*, eth::Assembly const*> const& _compiledContracts
+	);
 	/// Adds the code that is run at creation time. Should be run after exchanging the run-time context
 	/// with a new and initialized context. Adds the constructor code.
 	void packIntoContractCreator(ContractDefinition const& _contract, CompilerContext const& _runtimeContext);
diff --git a/libsolidity/CompilerContext.cpp b/libsolidity/CompilerContext.cpp
index af93578f..717627a5 100644
--- a/libsolidity/CompilerContext.cpp
+++ b/libsolidity/CompilerContext.cpp
@@ -65,7 +65,7 @@ void CompilerContext::removeVariable(VariableDeclaration const& _declaration)
 	m_localVariables.erase(&_declaration);
 }
 
-bytes const& CompilerContext::compiledContract(const ContractDefinition& _contract) const
+eth::Assembly const& CompilerContext::compiledContract(const ContractDefinition& _contract) const
 {
 	auto ret = m_compiledContracts.find(&_contract);
 	solAssert(ret != m_compiledContracts.end(), "Compiled contract not found.");
diff --git a/libsolidity/CompilerContext.h b/libsolidity/CompilerContext.h
index 590c8797..39f4e75f 100644
--- a/libsolidity/CompilerContext.h
+++ b/libsolidity/CompilerContext.h
@@ -47,8 +47,8 @@ public:
 	void addVariable(VariableDeclaration const& _declaration, unsigned _offsetToCurrent = 0);
 	void removeVariable(VariableDeclaration const& _declaration);
 
-	void setCompiledContracts(std::map<ContractDefinition const*, bytes const*> const& _contracts) { m_compiledContracts = _contracts; }
-	bytes const& compiledContract(ContractDefinition const& _contract) const;
+	void setCompiledContracts(std::map<ContractDefinition const*, eth::Assembly const*> const& _contracts) { m_compiledContracts = _contracts; }
+	eth::Assembly const& compiledContract(ContractDefinition const& _contract) const;
 
 	void setStackOffset(int _offset) { m_asm.setDeposit(_offset); }
 	void adjustStackOffset(int _adjustment) { m_asm.adjustDeposit(_adjustment); }
@@ -112,6 +112,8 @@ public:
 	void appendProgramSize() { return m_asm.appendProgramSize(); }
 	/// Adds data to the data section, pushes a reference to the stack
 	eth::AssemblyItem appendData(bytes const& _data) { return m_asm.append(_data); }
+	/// Appends the address (virtual, will be filled in by linker) of a library.
+	void appendLibraryAddress(std::string const& _identifier) { m_asm.appendLibraryAddress(_identifier); }
 	/// Resets the stack of visited nodes with a new stack having only @c _node
 	void resetVisitedNodes(ASTNode const* _node);
 	/// Pops the stack of visited nodes
@@ -135,8 +137,8 @@ public:
 		return m_asm.stream(_stream, "", _sourceCodes, _inJsonFormat);
 	}
 
-	bytes assembledBytecode() { return m_asm.assemble(); }
-	bytes assembledRuntimeBytecode(size_t _subIndex) { m_asm.assemble(); return m_asm.data(u256(_subIndex)); }
+	eth::LinkerObject const& assembledObject() { return m_asm.assemble(); }
+	eth::LinkerObject const& assembledRuntimeObject(size_t _subIndex) { return m_asm.sub(_subIndex).assemble(); }
 
 	/**
 	 * Helper class to pop the visited nodes stack when a scope closes
@@ -164,7 +166,7 @@ private:
 	/// Magic global variables like msg, tx or this, distinguished by type.
 	std::set<Declaration const*> m_magicGlobals;
 	/// Other already compiled contracts to be used in contract creation calls.
-	std::map<ContractDefinition const*, bytes const*> m_compiledContracts;
+	std::map<ContractDefinition const*, eth::Assembly const*> m_compiledContracts;
 	/// Storage offsets of state variables
 	std::map<Declaration const*, std::pair<u256, unsigned>> m_stateVariables;
 	/// Offsets of local variables on the stack (relative to stack base).
diff --git a/libsolidity/CompilerStack.cpp b/libsolidity/CompilerStack.cpp
index 385533b2..3da982a4 100644
--- a/libsolidity/CompilerStack.cpp
+++ b/libsolidity/CompilerStack.cpp
@@ -153,7 +153,7 @@ void CompilerStack::compile(bool _optimize, unsigned _runs)
 	if (!m_parseSuccessful)
 		parse();
 
-	map<ContractDefinition const*, bytes const*> contractBytecode;
+	map<ContractDefinition const*, eth::Assembly const*> compiledContracts;
 	for (Source const* source: m_sourceOrder)
 		for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 			if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
@@ -161,26 +161,24 @@ void CompilerStack::compile(bool _optimize, unsigned _runs)
 				if (!contract->isFullyImplemented())
 					continue;
 				shared_ptr<Compiler> compiler = make_shared<Compiler>(_optimize, _runs);
-				compiler->compileContract(*contract, contractBytecode);
+				compiler->compileContract(*contract, compiledContracts);
 				Contract& compiledContract = m_contracts.at(contract->name());
-				compiledContract.bytecode = compiler->assembledBytecode();
-				compiledContract.runtimeBytecode = compiler->runtimeBytecode();
-				compiledContract.compiler = move(compiler);
-				compiler = make_shared<Compiler>(_optimize, _runs);
-				compiler->compileContract(*contract, contractBytecode);
-				contractBytecode[compiledContract.contract] = &compiledContract.bytecode;
+				compiledContract.compiler = compiler;
+				compiledContract.object = compiler->assembledObject();
+				compiledContract.runtimeObject = compiler->runtimeObject();
+				compiledContracts[compiledContract.contract] = &compiler->assembly();
 
 				Compiler cloneCompiler(_optimize, _runs);
-				cloneCompiler.compileClone(*contract, contractBytecode);
-				compiledContract.cloneBytecode = cloneCompiler.assembledBytecode();
+				cloneCompiler.compileClone(*contract, compiledContracts);
+				compiledContract.cloneObject = cloneCompiler.assembledObject();
 			}
 }
 
-bytes const& CompilerStack::compile(string const& _sourceCode, bool _optimize)
+eth::LinkerObject const& CompilerStack::compile(string const& _sourceCode, bool _optimize)
 {
 	parse(_sourceCode);
 	compile(_optimize);
-	return bytecode();
+	return object();
 }
 
 eth::AssemblyItems const* CompilerStack::assemblyItems(string const& _contractName) const
@@ -195,24 +193,28 @@ eth::AssemblyItems const* CompilerStack::runtimeAssemblyItems(string const& _con
 	return currentContract.compiler ? &contract(_contractName).compiler->runtimeAssemblyItems() : nullptr;
 }
 
-bytes const& CompilerStack::bytecode(string const& _contractName) const
+eth::LinkerObject const& CompilerStack::object(string const& _contractName) const
 {
-	return contract(_contractName).bytecode;
+	return contract(_contractName).object;
 }
 
-bytes const& CompilerStack::runtimeBytecode(string const& _contractName) const
+eth::LinkerObject const& CompilerStack::runtimeObject(string const& _contractName) const
 {
-	return contract(_contractName).runtimeBytecode;
+	return contract(_contractName).runtimeObject;
 }
 
-bytes const& CompilerStack::cloneBytecode(string const& _contractName) const
+eth::LinkerObject const& CompilerStack::cloneObject(string const& _contractName) const
 {
-	return contract(_contractName).cloneBytecode;
+	return contract(_contractName).cloneObject;
 }
 
 dev::h256 CompilerStack::contractCodeHash(string const& _contractName) const
 {
-	return dev::sha3(runtimeBytecode(_contractName));
+	auto const& obj = runtimeObject(_contractName);
+	if (obj.bytecode.empty() || !obj.linkReferences.empty())
+		return dev::h256();
+	else
+		return dev::sha3(obj.bytecode);
 }
 
 Json::Value CompilerStack::streamAssembly(ostream& _outStream, string const& _contractName, StringMap _sourceCodes, bool _inJsonFormat) const
@@ -305,7 +307,7 @@ size_t CompilerStack::functionEntryPoint(
 	return 0;
 }
 
-bytes CompilerStack::staticCompile(std::string const& _sourceCode, bool _optimize)
+eth::LinkerObject CompilerStack::staticCompile(std::string const& _sourceCode, bool _optimize)
 {
 	CompilerStack stack;
 	return stack.compile(_sourceCode, _optimize);
diff --git a/libsolidity/CompilerStack.h b/libsolidity/CompilerStack.h
index 0d812e02..8db8aff4 100644
--- a/libsolidity/CompilerStack.h
+++ b/libsolidity/CompilerStack.h
@@ -32,6 +32,7 @@
 #include <libdevcore/Common.h>
 #include <libdevcore/FixedHash.h>
 #include <libevmasm/SourceLocation.h>
+#include <libevmasm/LinkerObject.h>
 
 namespace dev
 {
@@ -92,23 +93,25 @@ public:
 	/// Compiles the source units that were previously added and parsed.
 	void compile(bool _optimize = false, unsigned _runs = 200);
 	/// Parses and compiles the given source code.
-	/// @returns the compiled bytecode
-	bytes const& compile(std::string const& _sourceCode, bool _optimize = false);
+	/// @returns the compiled linker object
+	eth::LinkerObject const& compile(std::string const& _sourceCode, bool _optimize = false);
 
-	/// @returns the assembled bytecode for a contract.
-	bytes const& bytecode(std::string const& _contractName = "") const;
-	/// @returns the runtime bytecode for the contract, i.e. the code that is returned by the constructor.
-	bytes const& runtimeBytecode(std::string const& _contractName = "") const;
+	/// @returns the assembled bytecode for a contract (empty if it has to be linked or lacks implementation).
+	eth::LinkerObject const& object(std::string const& _contractName = "") const;
+	/// @returns the runtime bytecode for the contract (empty if it has to be linked or lacks implementation).
+	eth::LinkerObject const& runtimeObject(std::string const& _contractName = "") const;
 	/// @returns the bytecode of a contract that uses an already deployed contract via CALLCODE.
 	/// The returned bytes will contain a sequence of 20 bytes of the format "XXX...XXX" which have to
 	/// substituted by the actual address. Note that this sequence starts end ends in three X
 	/// characters but can contain anything in between.
-	bytes const& cloneBytecode(std::string const& _contractName = "") const;
+	eth::LinkerObject const& cloneObject(std::string const& _contractName = "") const;
 	/// @returns normal contract assembly items
 	eth::AssemblyItems const* assemblyItems(std::string const& _contractName = "") const;
 	/// @returns runtime contract assembly items
 	eth::AssemblyItems const* runtimeAssemblyItems(std::string const& _contractName = "") const;
-	/// @returns hash of the runtime bytecode for the contract, i.e. the code that is returned by the constructor.
+	/// @returns hash of the runtime bytecode for the contract, i.e. the code that is
+	/// returned by the constructor or the zero-h256 if the contract still needs to be linked or
+	/// does not have runtime code.
 	dev::h256 contractCodeHash(std::string const& _contractName = "") const;
 
 	/// Streams a verbose version of the assembly to @a _outStream.
@@ -146,7 +149,7 @@ public:
 
 	/// Compile the given @a _sourceCode to bytecode. If a scanner is provided, it is used for
 	/// scanning the source code - this is useful for printing exception information.
-	static bytes staticCompile(std::string const& _sourceCode, bool _optimize = false);
+	static eth::LinkerObject staticCompile(std::string const& _sourceCode, bool _optimize = false);
 
 	/// Helper function for logs printing. Do only use in error cases, it's quite expensive.
 	/// line and columns are numbered starting from 1 with following order:
@@ -170,9 +173,9 @@ private:
 	{
 		ContractDefinition const* contract = nullptr;
 		std::shared_ptr<Compiler> compiler;
-		bytes bytecode;
-		bytes runtimeBytecode;
-		bytes cloneBytecode;
+		eth::LinkerObject object;
+		eth::LinkerObject runtimeObject;
+		eth::LinkerObject cloneObject;
 		std::shared_ptr<InterfaceHandler> interfaceHandler;
 		mutable std::unique_ptr<std::string const> interface;
 		mutable std::unique_ptr<std::string const> solidityInterface;
diff --git a/libsolidity/ExpressionCompiler.cpp b/libsolidity/ExpressionCompiler.cpp
index d5a8362e..b22a78dc 100644
--- a/libsolidity/ExpressionCompiler.cpp
+++ b/libsolidity/ExpressionCompiler.cpp
@@ -454,12 +454,11 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 			ContractDefinition const& contract =
 				dynamic_cast<ContractType const&>(*function.returnParameterTypes().front()).contractDefinition();
 			// copy the contract's code into memory
-			bytes const& bytecode = m_context.compiledContract(contract);
+			eth::Assembly const& assembly = m_context.compiledContract(contract);
 			utils().fetchFreeMemoryPointer();
-			m_context << u256(bytecode.size()) << eth::Instruction::DUP1;
-			//@todo could be done by actually appending the Assembly, but then we probably need to compile
-			// multiple times. Will revisit once external fuctions are inlined.
-			m_context.appendData(bytecode);
+			// pushes size
+			eth::AssemblyItem subroutine = m_context.addSubroutine(assembly);
+			m_context << eth::Instruction::DUP1 << subroutine;
 			m_context << eth::Instruction::DUP4 << eth::Instruction::CODECOPY;
 
 			m_context << eth::Instruction::ADD;
@@ -773,9 +772,15 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 
 		if (dynamic_cast<ContractType const*>(type.actualType().get()))
 		{
-			auto const* function = dynamic_cast<FunctionDefinition const*>(_memberAccess.referencedDeclaration());
-			solAssert(!!function, "Function not found in member access");
-			m_context << m_context.functionEntryLabel(*function).pushTag();
+			auto const& funType = dynamic_cast<FunctionType const&>(*_memberAccess.type());
+			if (funType.location() != FunctionType::Location::Internal)
+				m_context << funType.externalIdentifier();
+			else
+			{
+				auto const* function = dynamic_cast<FunctionDefinition const*>(_memberAccess.referencedDeclaration());
+				solAssert(!!function, "Function not found in member access");
+				m_context << m_context.functionEntryLabel(*function).pushTag();
+			}
 		}
 		else if (auto enumType = dynamic_cast<EnumType const*>(type.actualType().get()))
 			m_context << enumType->memberValue(_memberAccess.memberName());
@@ -924,9 +929,11 @@ void ExpressionCompiler::endVisit(Identifier const& _identifier)
 			utils().convertType(*variable->value()->type(), *variable->type());
 		}
 	}
-	else if (dynamic_cast<ContractDefinition const*>(declaration))
+	else if (auto contract = dynamic_cast<ContractDefinition const*>(declaration))
 	{
-		// no-op
+		if (contract->isLibrary())
+			//@todo name should be unique, change once we have module management
+			m_context.appendLibraryAddress(contract->name());
 	}
 	else if (dynamic_cast<EventDefinition const*>(declaration))
 	{
diff --git a/libsolidity/Parser.cpp b/libsolidity/Parser.cpp
index 7f779ed0..24f7734c 100644
--- a/libsolidity/Parser.cpp
+++ b/libsolidity/Parser.cpp
@@ -71,13 +71,14 @@ ASTPointer<SourceUnit> Parser::parse(shared_ptr<Scanner> const& _scanner)
 	vector<ASTPointer<ASTNode>> nodes;
 	while (m_scanner->currentToken() != Token::EOS)
 	{
-		switch (m_scanner->currentToken())
+		switch (auto token = m_scanner->currentToken())
 		{
 		case Token::Import:
 			nodes.push_back(parseImportDirective());
 			break;
 		case Token::Contract:
-			nodes.push_back(parseContractDefinition());
+		case Token::Library:
+			nodes.push_back(parseContractDefinition(token == Token::Library));
 			break;
 		default:
 			BOOST_THROW_EXCEPTION(createParserError(std::string("Expected import directive or contract definition.")));
@@ -113,13 +114,13 @@ ASTPointer<ImportDirective> Parser::parseImportDirective()
 	return nodeFactory.createNode<ImportDirective>(url);
 }
 
-ASTPointer<ContractDefinition> Parser::parseContractDefinition()
+ASTPointer<ContractDefinition> Parser::parseContractDefinition(bool _isLibrary)
 {
 	ASTNodeFactory nodeFactory(*this);
 	ASTPointer<ASTString> docString;
 	if (m_scanner->currentCommentLiteral() != "")
 		docString = make_shared<ASTString>(m_scanner->currentCommentLiteral());
-	expectToken(Token::Contract);
+	expectToken(_isLibrary ? Token::Library : Token::Contract);
 	ASTPointer<ASTString> name = expectIdentifierToken();
 	vector<ASTPointer<InheritanceSpecifier>> baseContracts;
 	vector<ASTPointer<StructDefinition>> structs;
@@ -177,7 +178,8 @@ ASTPointer<ContractDefinition> Parser::parseContractDefinition()
 		stateVariables,
 		functions,
 		modifiers,
-		events
+		events,
+		_isLibrary
 	);
 }
 
diff --git a/libsolidity/Parser.h b/libsolidity/Parser.h
index 36302f74..79eb73f0 100644
--- a/libsolidity/Parser.h
+++ b/libsolidity/Parser.h
@@ -61,15 +61,17 @@ private:
 	///@{
 	///@name Parsing functions for the AST nodes
 	ASTPointer<ImportDirective> parseImportDirective();
-	ASTPointer<ContractDefinition> parseContractDefinition();
+	ASTPointer<ContractDefinition> parseContractDefinition(bool _isLibrary);
 	ASTPointer<InheritanceSpecifier> parseInheritanceSpecifier();
 	Declaration::Visibility parseVisibilitySpecifier(Token::Value _token);
 	ASTPointer<FunctionDefinition> parseFunctionDefinition(ASTString const* _contractName);
 	ASTPointer<StructDefinition> parseStructDefinition();
 	ASTPointer<EnumDefinition> parseEnumDefinition();
 	ASTPointer<EnumValue> parseEnumValue();
-	ASTPointer<VariableDeclaration> parseVariableDeclaration(VarDeclParserOptions const& _options = VarDeclParserOptions(),
-		ASTPointer<TypeName> const& _lookAheadArrayType = ASTPointer<TypeName>());
+	ASTPointer<VariableDeclaration> parseVariableDeclaration(
+		VarDeclParserOptions const& _options = VarDeclParserOptions(),
+		ASTPointer<TypeName> const& _lookAheadArrayType = ASTPointer<TypeName>()
+	);
 	ASTPointer<ModifierDefinition> parseModifierDefinition();
 	ASTPointer<EventDefinition> parseEventDefinition();
 	ASTPointer<ModifierInvocation> parseModifierInvocation();
diff --git a/libsolidity/Token.h b/libsolidity/Token.h
index bc242ecf..1632a693 100644
--- a/libsolidity/Token.h
+++ b/libsolidity/Token.h
@@ -160,6 +160,7 @@ namespace solidity
 	K(Internal, "internal", 0)                                         \
 	K(Import, "import", 0)                                             \
 	K(Is, "is", 0)                                                     \
+	K(Library, "library", 0)                                           \
 	K(Mapping, "mapping", 0)                                           \
 	K(Memory, "memory", 0)                                             \
 	K(Modifier, "modifier", 0)                                         \
@@ -305,7 +306,7 @@ namespace solidity
 	/* Identifiers (not keywords or future reserved words). */         \
 	T(Identifier, NULL, 0)                                             \
 	\
-	/* Keywords reserved for future. use. */                           \
+	/* Keywords reserved for future use. */                            \
 	K(As, "as", 0)                                                     \
 	K(Case, "case", 0)                                                 \
 	K(Catch, "catch", 0)                                               \
diff --git a/libsolidity/Types.cpp b/libsolidity/Types.cpp
index d1c59ba5..5bc7cd43 100644
--- a/libsolidity/Types.cpp
+++ b/libsolidity/Types.cpp
@@ -971,7 +971,7 @@ MemberList const& ContractType::members() const
 			for (auto const& it: m_contract.interfaceFunctions())
 				members.push_back(MemberList::Member(
 					it.second->declaration().name(),
-					it.second->asMemberFunction(),
+					it.second->asMemberFunction(false),
 					&it.second->declaration()
 				));
 		m_members.reset(new MemberList(members));
@@ -1538,7 +1538,7 @@ TypePointer FunctionType::copyAndSetGasOrValue(bool _setGas, bool _setValue) con
 	);
 }
 
-FunctionTypePointer FunctionType::asMemberFunction() const
+FunctionTypePointer FunctionType::asMemberFunction(bool _inLibrary) const
 {
 	TypePointers parameterTypes;
 	for (auto const& t: m_parameterTypes)
@@ -1563,7 +1563,7 @@ FunctionTypePointer FunctionType::asMemberFunction() const
 		returnParameterTypes,
 		m_parameterNames,
 		returnParameterNames,
-		m_location,
+		_inLibrary ? Location::CallCode : m_location,
 		m_arbitraryParameters,
 		m_declaration,
 		m_gasSet,
@@ -1633,21 +1633,39 @@ u256 TypeType::storageSize() const
 			<< errinfo_comment("Storage size of non-storable type type requested."));
 }
 
+unsigned TypeType::sizeOnStack() const
+{
+	if (auto contractType = dynamic_cast<ContractType const*>(m_actualType.get()))
+		if (contractType->contractDefinition().isLibrary())
+			return 1;
+	return 0;
+}
+
 MemberList const& TypeType::members() const
 {
 	// We need to lazy-initialize it because of recursive references.
 	if (!m_members)
 	{
 		MemberList::MemberMap members;
-		if (m_actualType->category() == Category::Contract && m_currentContract != nullptr)
+		if (m_actualType->category() == Category::Contract)
 		{
 			ContractDefinition const& contract = dynamic_cast<ContractType const&>(*m_actualType).contractDefinition();
-			vector<ContractDefinition const*> currentBases = m_currentContract->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.
-				for (Declaration const* decl: contract.inheritableMembers())
-					members.push_back(MemberList::Member(decl->name(), decl->type(), decl));
+			if (contract.isLibrary())
+				for (auto const& it: contract.interfaceFunctions())
+					members.push_back(MemberList::Member(
+						it.second->declaration().name(),
+						it.second->asMemberFunction(true), // use callcode
+						&it.second->declaration()
+					));
+			else if (m_currentContract != nullptr)
+			{
+				vector<ContractDefinition const*> currentBases = m_currentContract->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.
+					for (Declaration const* decl: contract.inheritableMembers())
+						members.push_back(MemberList::Member(decl->name(), decl->type(), decl));
+			}
 		}
 		else if (m_actualType->category() == Category::Enum)
 		{
diff --git a/libsolidity/Types.h b/libsolidity/Types.h
index 17ae0ce0..11218b7a 100644
--- a/libsolidity/Types.h
+++ b/libsolidity/Types.h
@@ -517,7 +517,7 @@ private:
 };
 
 /**
- * The type of a contract instance, there is one distinct type for each contract definition.
+ * The type of a contract instance or library, there is one distinct type for each contract definition.
  */
 class ContractType: public Type
 {
@@ -788,7 +788,8 @@ public:
 	/// removed and the location of reference types is changed from CallData to Memory.
 	/// This is needed if external functions are called on other contracts, as they cannot return
 	/// dynamic values.
-	FunctionTypePointer asMemberFunction() const;
+	/// @param _inLibrary if true, uses CallCode as location.
+	FunctionTypePointer asMemberFunction(bool _inLibrary) const;
 
 private:
 	static TypePointers parseElementaryTypeVector(strings const& _types);
@@ -851,6 +852,7 @@ public:
 /**
  * The type of a type reference. The type of "uint32" when used in "a = uint32(2)" is an example
  * of a TypeType.
+ * For super contracts or libraries, this has members directly.
  */
 class TypeType: public Type
 {
@@ -865,7 +867,7 @@ public:
 	virtual bool canBeStored() const override { return false; }
 	virtual u256 storageSize() const override;
 	virtual bool canLiveOutsideStorage() const override { return false; }
-	virtual unsigned sizeOnStack() const override { return 0; }
+	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;
 
diff --git a/libsolidity/grammar.txt b/libsolidity/grammar.txt
index 6503516c..467aebee 100644
--- a/libsolidity/grammar.txt
+++ b/libsolidity/grammar.txt
@@ -1,4 +1,4 @@
-ContractDefinition = 'contract' Identifier
+ContractDefinition = ( 'contract' | 'library' ) Identifier
                      ( 'is' InheritanceSpecifier (',' InheritanceSpecifier )* )?
                      '{' ContractPart* '}'
 ContractPart = StateVariableDeclaration | StructDefinition | ModifierDefinition | FunctionDefinition | EnumDefinition