BREAKING: Implement delegatecall and make default for library calls.

6 files changed, 51 insertions, 43 deletions

diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index bca83d59..0696b908 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -333,6 +333,7 @@ MemberList::MemberMap IntegerType::nativeMembers(ContractDefinition const*) cons
 			{"balance", make_shared<IntegerType >(256)},
 			{"call", make_shared<FunctionType>(strings(), strings{"bool"}, FunctionType::Location::Bare, true)},
 			{"callcode", make_shared<FunctionType>(strings(), strings{"bool"}, FunctionType::Location::BareCallCode, true)},
+			{"delegatecall", make_shared<FunctionType>(strings(), strings{"bool"}, FunctionType::Location::BareDelegateCall, true)},
 			{"send", make_shared<FunctionType>(strings{"uint"}, strings{"bool"}, FunctionType::Location::Send)}
 		};
 	else
@@ -1561,9 +1562,9 @@ unsigned FunctionType::sizeOnStack() const
 	}
 
 	unsigned size = 0;
-	if (location == Location::External || location == Location::CallCode)
+	if (location == Location::External || location == Location::CallCode || location == Location::DelegateCall)
 		size = 2;
-	else if (location == Location::Bare || location == Location::BareCallCode)
+	else if (location == Location::Bare || location == Location::BareCallCode || location == Location::BareDelegateCall)
 		size = 1;
 	else if (location == Location::Internal)
 		size = 1;
@@ -1619,9 +1620,11 @@ MemberList::MemberMap FunctionType::nativeMembers(ContractDefinition const*) con
 	case Location::RIPEMD160:
 	case Location::Bare:
 	case Location::BareCallCode:
+	case Location::BareDelegateCall:
 	{
-		MemberList::MemberMap members{
-			{
+		MemberList::MemberMap members;
+		if (m_location != Location::BareDelegateCall)
+			members.push_back(MemberList::Member(
 				"value",
 				make_shared<FunctionType>(
 					parseElementaryTypeVector({"uint"}),
@@ -1634,25 +1637,22 @@ MemberList::MemberMap FunctionType::nativeMembers(ContractDefinition const*) con
 					m_gasSet,
 					m_valueSet
 				)
-			}
-		};
+			));
 		if (m_location != Location::Creation)
-			members.push_back(
-				MemberList::Member(
-					"gas",
-					make_shared<FunctionType>(
-						parseElementaryTypeVector({"uint"}),
-						TypePointers{copyAndSetGasOrValue(true, false)},
-						strings(),
-						strings(),
-						Location::SetGas,
-						false,
-						nullptr,
-						m_gasSet,
-						m_valueSet
-					)
+			members.push_back(MemberList::Member(
+				"gas",
+				make_shared<FunctionType>(
+					parseElementaryTypeVector({"uint"}),
+					TypePointers{copyAndSetGasOrValue(true, false)},
+					strings(),
+					strings(),
+					Location::SetGas,
+					false,
+					nullptr,
+					m_gasSet,
+					m_valueSet
 				)
-			);
+			));
 		return members;
 	}
 	default:
@@ -1700,6 +1700,7 @@ bool FunctionType::isBareCall() const
 	{
 	case Location::Bare:
 	case Location::BareCallCode:
+	case Location::BareDelegateCall:
 	case Location::ECRecover:
 	case Location::SHA256:
 	case Location::RIPEMD160:
@@ -1785,7 +1786,7 @@ FunctionTypePointer FunctionType::asMemberFunction(bool _inLibrary, bool _bound)
 		returnParameterTypes,
 		m_parameterNames,
 		returnParameterNames,
-		_inLibrary ? Location::CallCode : m_location,
+		_inLibrary ? Location::DelegateCall : m_location,
 		m_arbitraryParameters,
 		m_declaration,
 		m_gasSet,
@@ -1884,7 +1885,7 @@ MemberList::MemberMap TypeType::nativeMembers(ContractDefinition const* _current
 			for (auto const& it: contract.interfaceFunctions())
 				members.push_back(MemberList::Member(
 					it.second->declaration().name(),
-					it.second->asMemberFunction(true), // use callcode
+					it.second->asMemberFunction(true),
 					&it.second->declaration()
 				));
 		if (isBase)
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index b4a2d573..189dd10a 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -732,8 +732,10 @@ public:
 		Internal, ///< stack-call using plain JUMP
 		External, ///< external call using CALL
 		CallCode, ///< extercnal call using CALLCODE, i.e. not exchanging the storage
+		DelegateCall, ///< extercnal call using DELEGATECALL, i.e. not exchanging the storage
 		Bare, ///< CALL without function hash
 		BareCallCode, ///< CALLCODE without function hash
+		BareDelegateCall, ///< DELEGATECALL without function hash
 		Creation, ///< external call using CREATE
 		Send, ///< CALL, but without data and gas
 		SHA3, ///< SHA3
@@ -869,7 +871,7 @@ 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.
-	/// @param _inLibrary if true, uses CallCode as location.
+	/// @param _inLibrary if true, uses DelegateCall as location.
 	/// @param _bound if true, the argumenst are placed as `arg1.functionName(arg2, ..., argn)`.
 	FunctionTypePointer asMemberFunction(bool _inLibrary, bool _bound = false) const;
 
diff --git a/libsolidity/codegen/Compiler.cpp b/libsolidity/codegen/Compiler.cpp
index 18803b71..c7eb71a8 100644
--- a/libsolidity/codegen/Compiler.cpp
+++ b/libsolidity/codegen/Compiler.cpp
@@ -773,15 +773,13 @@ eth::Assembly Compiler::cloneRuntime()
 	a << u256(0) << eth::Instruction::DUP1 << eth::Instruction::CALLDATACOPY;
 	//@todo adjust for larger return values, make this dynamic.
 	a << u256(0x20) << u256(0) << eth::Instruction::CALLDATASIZE;
-	// unfortunately, we have to send the value again, so that CALLVALUE returns the correct value
-	// in the callcoded contract.
-	a << u256(0) << eth::Instruction::CALLVALUE;
+	a << u256(0);
 	// this is the address which has to be substituted by the linker.
 	//@todo implement as special "marker" AssemblyItem.
 	a << u256("0xcafecafecafecafecafecafecafecafecafecafe");
-	a << u256(schedule.callGas + schedule.callValueTransferGas + 10) << eth::Instruction::GAS << eth::Instruction::SUB;
-	a << eth::Instruction::CALLCODE;
-	//Propagate error condition (if CALLCODE pushes 0 on stack).
+	a << u256(schedule.callGas + 10) << eth::Instruction::GAS << eth::Instruction::SUB;
+	a << eth::Instruction::DELEGATECALL;
+	//Propagate error condition (if DELEGATECALL pushes 0 on stack).
 	a << eth::Instruction::ISZERO;
 	a.appendJumpI(a.errorTag());
 	//@todo adjust for larger return values, make this dynamic.
diff --git a/libsolidity/codegen/Compiler.h b/libsolidity/codegen/Compiler.h
index 9d069f7c..fa33bd30 100644
--- a/libsolidity/codegen/Compiler.h
+++ b/libsolidity/codegen/Compiler.h
@@ -44,7 +44,7 @@ public:
 		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
+	/// Compiles a contract that uses DELEGATECALL 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,
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 58db07b1..e0b2b5f6 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -465,8 +465,8 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 	{
 		FunctionType const& function = *functionType;
 		if (function.bound())
-			// Only callcode functions can be bound, this might be lifted later.
-			solAssert(function.location() == Location::CallCode, "");
+			// Only delegatecall functions can be bound, this might be lifted later.
+			solAssert(function.location() == Location::DelegateCall, "");
 		switch (function.location())
 		{
 		case Location::Internal:
@@ -492,8 +492,10 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 		}
 		case Location::External:
 		case Location::CallCode:
+		case Location::DelegateCall:
 		case Location::Bare:
 		case Location::BareCallCode:
+		case Location::BareDelegateCall:
 			_functionCall.expression().accept(*this);
 			appendExternalFunctionCall(function, arguments);
 			break;
@@ -875,7 +877,7 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 			);
 			m_context << eth::Instruction::BALANCE;
 		}
-		else if ((set<string>{"send", "call", "callcode"}).count(member))
+		else if ((set<string>{"send", "call", "callcode", "delegatecall"}).count(member))
 			utils().convertType(
 				*_memberAccess.expression().annotation().type,
 				IntegerType(0, IntegerType::Modifier::Address),
@@ -1356,6 +1358,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
 	FunctionKind funKind = _functionType.location();
 	bool returnSuccessCondition = funKind == FunctionKind::Bare || funKind == FunctionKind::BareCallCode;
 	bool isCallCode = funKind == FunctionKind::BareCallCode || funKind == FunctionKind::CallCode;
+	bool isDelegateCall = funKind == FunctionKind::BareDelegateCall || funKind == FunctionKind::DelegateCall;
 
 	unsigned retSize = 0;
 	if (returnSuccessCondition)
@@ -1371,13 +1374,13 @@ void ExpressionCompiler::appendExternalFunctionCall(
 	TypePointers argumentTypes;
 	TypePointers parameterTypes = _functionType.parameterTypes();
 	bool manualFunctionId =
-		(funKind == FunctionKind::Bare || funKind == FunctionKind::BareCallCode) &&
+		(funKind == FunctionKind::Bare || funKind == FunctionKind::BareCallCode || funKind == FunctionKind::BareDelegateCall) &&
 		!_arguments.empty() &&
 		_arguments.front()->annotation().type->mobileType()->calldataEncodedSize(false) ==
 			CompilerUtils::dataStartOffset;
 	if (manualFunctionId)
 	{
-		// If we have a BareCall or BareCallCode and the first type has exactly 4 bytes, use it as
+		// If we have a Bare* and the first type has exactly 4 bytes, use it as
 		// function identifier.
 		_arguments.front()->accept(*this);
 		utils().convertType(
@@ -1416,7 +1419,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
 		parameterTypes,
 		_functionType.padArguments(),
 		_functionType.takesArbitraryParameters(),
-		isCallCode
+		isCallCode || isDelegateCall
 	);
 
 	// Stack now:
@@ -1435,8 +1438,10 @@ void ExpressionCompiler::appendExternalFunctionCall(
 	m_context << eth::Instruction::DUP2;
 
 	// CALL arguments: outSize, outOff, inSize, inOff (already present up to here)
-	// value, addr, gas (stack top)
-	if (_functionType.valueSet())
+	// [value,] addr, gas (stack top)
+	if (isDelegateCall)
+		solAssert(!_functionType.valueSet(), "Value set for delegatecall");
+	else if (_functionType.valueSet())
 		m_context << eth::dupInstruction(m_context.baseToCurrentStackOffset(valueStackPos));
 	else
 		m_context << u256(0);
@@ -1446,20 +1451,22 @@ void ExpressionCompiler::appendExternalFunctionCall(
 		m_context << eth::dupInstruction(m_context.baseToCurrentStackOffset(gasStackPos));
 	else
 	{
-		eth::EVMSchedule schedule;// TODO: Make relevant to current suppose context.
+		eth::EVMSchedule schedule;
 		// send all gas except the amount needed to execute "SUB" and "CALL"
 		// @todo this retains too much gas for now, needs to be fine-tuned.
 		u256 gasNeededByCaller = schedule.callGas + 10;
 		if (_functionType.valueSet())
 			gasNeededByCaller += schedule.callValueTransferGas;
-		if (!isCallCode)
+		if (!isCallCode && !isDelegateCall)
 			gasNeededByCaller += schedule.callNewAccountGas; // we never know
 		m_context <<
 			gasNeededByCaller <<
 			eth::Instruction::GAS <<
 			eth::Instruction::SUB;
 	}
-	if (isCallCode)
+	if (isDelegateCall)
+		m_context << eth::Instruction::DELEGATECALL;
+	else if (isCallCode)
 		m_context << eth::Instruction::CALLCODE;
 	else
 		m_context << eth::Instruction::CALL;
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index 517d0055..1d13a23c 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -124,7 +124,7 @@ public:
 	eth::LinkerObject const& object(std::string const& _contractName = "") const;
 	/// @returns the runtime object for the contract.
 	eth::LinkerObject const& runtimeObject(std::string const& _contractName = "") const;
-	/// @returns the bytecode of a contract that uses an already deployed contract via CALLCODE.
+	/// @returns the bytecode of a contract that uses an already deployed contract via DELEGATECALL.
 	/// 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.