/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2014
* Solidity AST to EVM bytecode compiler for expressions.
*/
#include <utility>
#include <numeric>
#include <libdevcore/Common.h>
#include <libdevcrypto/SHA3.h>
#include <libsolidity/AST.h>
#include <libsolidity/ExpressionCompiler.h>
#include <libsolidity/CompilerContext.h>
#include <libsolidity/CompilerUtils.h>
using namespace std;
namespace dev
{
namespace solidity
{
void ExpressionCompiler::compileExpression(CompilerContext& _context, Expression const& _expression, bool _optimize)
{
ExpressionCompiler compiler(_context, _optimize);
_expression.accept(compiler);
}
void ExpressionCompiler::appendTypeConversion(CompilerContext& _context, Type const& _typeOnStack,
Type const& _targetType, bool _cleanupNeeded)
{
ExpressionCompiler compiler(_context);
compiler.appendTypeConversion(_typeOnStack, _targetType, _cleanupNeeded);
}
void ExpressionCompiler::appendStateVariableAccessor(CompilerContext& _context, VariableDeclaration const& _varDecl, bool _optimize)
{
ExpressionCompiler compiler(_context, _optimize);
compiler.appendStateVariableAccessor(_varDecl);
}
bool ExpressionCompiler::visit(Assignment const& _assignment)
{
_assignment.getRightHandSide().accept(*this);
appendTypeConversion(*_assignment.getRightHandSide().getType(), *_assignment.getType());
_assignment.getLeftHandSide().accept(*this);
solAssert(m_currentLValue.isValid(), "LValue not retrieved.");
Token::Value op = _assignment.getAssignmentOperator();
if (op != Token::ASSIGN) // compound assignment
{
if (m_currentLValue.storesReferenceOnStack())
m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2;
m_currentLValue.retrieveValue(_assignment.getType(), _assignment.getLocation(), true);
appendOrdinaryBinaryOperatorCode(Token::AssignmentToBinaryOp(op), *_assignment.getType());
if (m_currentLValue.storesReferenceOnStack())
m_context << eth::Instruction::SWAP1;
}
m_currentLValue.storeValue(_assignment);
m_currentLValue.reset();
return false;
}
bool ExpressionCompiler::visit(UnaryOperation const& _unaryOperation)
{
//@todo type checking and creating code for an operator should be in the same place:
// the operator should know how to convert itself and to which types it applies, so
// put this code together with "Type::acceptsBinary/UnaryOperator" into a class that
// represents the operator
if (_unaryOperation.getType()->getCategory() == Type::Category::INTEGER_CONSTANT)
{
m_context << _unaryOperation.getType()->literalValue(nullptr);
return false;
}
_unaryOperation.getSubExpression().accept(*this);
switch (_unaryOperation.getOperator())
{
case Token::NOT: // !
m_context << eth::Instruction::ISZERO;
break;
case Token::BIT_NOT: // ~
m_context << eth::Instruction::NOT;
break;
case Token::DELETE: // delete
solAssert(m_currentLValue.isValid(), "LValue not retrieved.");
m_currentLValue.setToZero(_unaryOperation);
m_currentLValue.reset();
break;
case Token::INC: // ++ (pre- or postfix)
case Token::DEC: // -- (pre- or postfix)
solAssert(m_currentLValue.isValid(), "LValue not retrieved.");
m_currentLValue.retrieveValue(_unaryOperation.getType(), _unaryOperation.getLocation());
if (!_unaryOperation.isPrefixOperation())
{
if (m_currentLValue.storesReferenceOnStack())
m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2;
else
m_context << eth::Instruction::DUP1;
}
m_context << u256(1);
if (_unaryOperation.getOperator() == Token::INC)
m_context << eth::Instruction::ADD;
else
m_context << eth::Instruction::SWAP1 << eth::Instruction::SUB; // @todo avoid the swap
// Stack for prefix: [ref] (*ref)+-1
// Stack for postfix: *ref [ref] (*ref)+-1
if (m_currentLValue.storesReferenceOnStack())
m_context << eth::Instruction::SWAP1;
m_currentLValue.storeValue(_unaryOperation, !_unaryOperation.isPrefixOperation());
m_currentLValue.reset();
break;
case Token::ADD: // +
// unary add, so basically no-op
break;
case Token::SUB: // -
m_context << u256(0) << eth::Instruction::SUB;
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid unary operator: " +
string(Token::toString(_unaryOperation.getOperator()))));
}
return false;
}
bool ExpressionCompiler::visit(BinaryOperation const& _binaryOperation)
{
Expression const& leftExpression = _binaryOperation.getLeftExpression();
Expression const& rightExpression = _binaryOperation.getRightExpression();
Type const& commonType = _binaryOperation.getCommonType();
Token::Value const c_op = _binaryOperation.getOperator();
if (c_op == Token::AND || c_op == Token::OR) // special case: short-circuiting
appendAndOrOperatorCode(_binaryOperation);
else if (commonType.getCategory() == Type::Category::INTEGER_CONSTANT)
m_context << commonType.literalValue(nullptr);
else
{
bool cleanupNeeded = commonType.getCategory() == Type::Category::INTEGER &&
(Token::isCompareOp(c_op) || c_op == Token::DIV || c_op == Token::MOD);
// for commutative operators, push the literal as late as possible to allow improved optimization
auto isLiteral = [](Expression const& _e)
{
return dynamic_cast<Literal const*>(&_e) || _e.getType()->getCategory() == Type::Category::INTEGER_CONSTANT;
};
bool swap = m_optimize && Token::isCommutativeOp(c_op) && isLiteral(rightExpression) && !isLiteral(leftExpression);
if (swap)
{
leftExpression.accept(*this);
appendTypeConversion(*leftExpression.getType(), commonType, cleanupNeeded);
rightExpression.accept(*this);
appendTypeConversion(*rightExpression.getType(), commonType, cleanupNeeded);
}
else
{
rightExpression.accept(*this);
appendTypeConversion(*rightExpression.getType(), commonType, cleanupNeeded);
leftExpression.accept(*this);
appendTypeConversion(*leftExpression.getType(), commonType, cleanupNeeded);
}
if (Token::isCompareOp(c_op))
appendCompareOperatorCode(c_op, commonType);
else
appendOrdinaryBinaryOperatorCode(c_op, commonType);
}
// do not visit the child nodes, we already did that explicitly
return false;
}
bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
{
using Location = FunctionType::Location;
if (_functionCall.isTypeConversion())
{
//@todo struct construction
solAssert(_functionCall.getArguments().size() == 1, "");
Expression const& firstArgument = *_functionCall.getArguments().front();
firstArgument.accept(*this);
appendTypeConversion(*firstArgument.getType(), *_functionCall.getType());
}
else
{
FunctionType const& function = dynamic_cast<FunctionType const&>(*_functionCall.getExpression().getType());
vector<ASTPointer<Expression const>> arguments = _functionCall.getArguments();
solAssert(arguments.size() == function.getParameterTypes().size(), "");
switch (function.getLocation())
{
case Location::INTERNAL:
{
// Calling convention: Caller pushes return address and arguments
// Callee removes them and pushes return values
eth::AssemblyItem returnLabel = m_context.pushNewTag();
for (unsigned i = 0; i < arguments.size(); ++i)
{
arguments[i]->accept(*this);
appendTypeConversion(*arguments[i]->getType(), *function.getParameterTypes()[i]);
}
_functionCall.getExpression().accept(*this);
m_context.appendJump();
m_context << returnLabel;
unsigned returnParametersSize = CompilerUtils::getSizeOnStack(function.getReturnParameterTypes());
// callee adds return parameters, but removes arguments and return label
m_context.adjustStackOffset(returnParametersSize - CompilerUtils::getSizeOnStack(function.getParameterTypes()) - 1);
// @todo for now, the return value of a function is its first return value, so remove
// all others
for (unsigned i = 1; i < function.getReturnParameterTypes().size(); ++i)
CompilerUtils(m_context).popStackElement(*function.getReturnParameterTypes()[i]);
break;
}
case Location::EXTERNAL:
case Location::BARE:
_functionCall.getExpression().accept(*this);
appendExternalFunctionCall(function, arguments, function.getLocation() == Location::BARE);
break;
case Location::CREATION:
{
_functionCall.getExpression().accept(*this);
solAssert(!function.gasSet(), "Gas limit set for contract creation.");
solAssert(function.getReturnParameterTypes().size() == 1, "");
ContractDefinition const& contract = dynamic_cast<ContractType const&>(
*function.getReturnParameterTypes().front()).getContractDefinition();
// copy the contract's code into memory
bytes const& bytecode = m_context.getCompiledContract(contract);
m_context << u256(bytecode.size());
//@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);
//@todo copy to memory position 0, shift as soon as we use memory
m_context << u256(0) << eth::Instruction::CODECOPY;
unsigned length = bytecode.size();
length += appendArgumentCopyToMemory(function.getParameterTypes(), arguments, length);
// size, offset, endowment
m_context << u256(length) << u256(0);
if (function.valueSet())
m_context << eth::dupInstruction(3);
else
m_context << u256(0);
m_context << eth::Instruction::CREATE;
if (function.valueSet())
m_context << eth::swapInstruction(1) << eth::Instruction::POP;
break;
}
case Location::SET_GAS:
{
// stack layout: contract_address function_id [gas] [value]
_functionCall.getExpression().accept(*this);
arguments.front()->accept(*this);
appendTypeConversion(*arguments.front()->getType(), IntegerType(256), true);
// Note that function is not the original function, but the ".gas" function.
// Its values of gasSet and valueSet is equal to the original function's though.
unsigned stackDepth = (function.gasSet() ? 1 : 0) + (function.valueSet() ? 1 : 0);
if (stackDepth > 0)
m_context << eth::swapInstruction(stackDepth);
if (function.gasSet())
m_context << eth::Instruction::POP;
break;
}
case Location::SET_VALUE:
// stack layout: contract_address function_id [gas] [value]
_functionCall.getExpression().accept(*this);
// Note that function is not the original function, but the ".value" function.
// Its values of gasSet and valueSet is equal to the original function's though.
if (function.valueSet())
m_context << eth::Instruction::POP;
arguments.front()->accept(*this);
break;
case Location::SEND:
_functionCall.getExpression().accept(*this);
m_context << u256(0); // 0 gas, we do not want to execute code
arguments.front()->accept(*this);
appendTypeConversion(*arguments.front()->getType(),
*function.getParameterTypes().front(), true);
appendExternalFunctionCall(FunctionType(TypePointers{}, TypePointers{},
Location::EXTERNAL, true, true), {}, true);
break;
case Location::SUICIDE:
arguments.front()->accept(*this);
appendTypeConversion(*arguments.front()->getType(), *function.getParameterTypes().front(), true);
m_context << eth::Instruction::SUICIDE;
break;
case Location::SHA3:
appendExpressionCopyToMemory(*function.getParameterTypes().front(), *arguments.front());
m_context << u256(32) << u256(0) << eth::Instruction::SHA3;
break;
case Location::LOG0:
case Location::LOG1:
case Location::LOG2:
case Location::LOG3:
case Location::LOG4:
{
unsigned logNumber = int(function.getLocation()) - int(Location::LOG0);
for (unsigned arg = logNumber; arg > 0; --arg)
{
arguments[arg]->accept(*this);
appendTypeConversion(*arguments[arg]->getType(), *function.getParameterTypes()[arg], true);
}
unsigned length = appendExpressionCopyToMemory(*function.getParameterTypes().front(),
*arguments.front());
solAssert(length == 32, "Log data should be 32 bytes long (for now).");
m_context << u256(length) << u256(0) << eth::logInstruction(logNumber);
break;
}
case Location::EVENT:
{
_functionCall.getExpression().accept(*this);
auto const& event = dynamic_cast<EventDefinition const&>(function.getDeclaration());
// Copy all non-indexed arguments to memory (data)
unsigned numIndexed = 0;
unsigned memLength = 0;
for (unsigned arg = 0; arg < arguments.size(); ++arg)
if (!event.getParameters()[arg]->isIndexed())
memLength += appendExpressionCopyToMemory(*function.getParameterTypes()[arg],
*arguments[arg], memLength);
// All indexed arguments go to the stack
for (unsigned arg = arguments.size(); arg > 0; --arg)
if (event.getParameters()[arg - 1]->isIndexed())
{
++numIndexed;
arguments[arg - 1]->accept(*this);
appendTypeConversion(*arguments[arg - 1]->getType(),
*function.getParameterTypes()[arg - 1], true);
}
m_context << u256(h256::Arith(dev::sha3(function.getCanonicalSignature(event.getName()))));
++numIndexed;
solAssert(numIndexed <= 4, "Too many indexed arguments.");
m_context << u256(memLength) << u256(0) << eth::logInstruction(numIndexed);
break;
}
case Location::BLOCKHASH:
{
arguments[0]->accept(*this);
appendTypeConversion(*arguments[0]->getType(), *function.getParameterTypes()[0], true);
m_context << eth::Instruction::BLOCKHASH;
break;
}
case Location::ECRECOVER:
case Location::SHA256:
case Location::RIPEMD160:
{
static const map<Location, u256> contractAddresses{{Location::ECRECOVER, 1},
{Location::SHA256, 2},
{Location::RIPEMD160, 3}};
m_context << contractAddresses.find(function.getLocation())->second;
appendExternalFunctionCall(function, arguments, true);
break;
}
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid function type."));
}
}
return false;
}
bool ExpressionCompiler::visit(NewExpression const&)
{
// code is created for the function call (CREATION) only
return false;
}
void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
{
ASTString const& member = _memberAccess.getMemberName();
switch (_memberAccess.getExpression().getType()->getCategory())
{
case Type::Category::CONTRACT:
{
bool alsoSearchInteger = false;
ContractType const& type = dynamic_cast<ContractType const&>(*_memberAccess.getExpression().getType());
if (type.isSuper())
m_context << m_context.getSuperFunctionEntryLabel(member, type.getContractDefinition()).pushTag();
else
{
// ordinary contract type
u256 identifier = type.getFunctionIdentifier(member);
if (identifier != Invalid256)
{
appendTypeConversion(type, IntegerType(0, IntegerType::Modifier::ADDRESS), true);
m_context << identifier;
}
else
// not found in contract, search in members inherited from address
alsoSearchInteger = true;
}
if (!alsoSearchInteger)
break;
}
case Type::Category::INTEGER:
if (member == "balance")
{
appendTypeConversion(*_memberAccess.getExpression().getType(),
IntegerType(0, IntegerType::Modifier::ADDRESS), true);
m_context << eth::Instruction::BALANCE;
}
else if (member == "send" || member.substr(0, min<size_t>(member.size(), 4)) == "call")
appendTypeConversion(*_memberAccess.getExpression().getType(),
IntegerType(0, IntegerType::Modifier::ADDRESS), true);
else
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid member access to integer."));
break;
case Type::Category::FUNCTION:
solAssert(!!_memberAccess.getExpression().getType()->getMemberType(member),
"Invalid member access to function.");
break;
case Type::Category::MAGIC:
// we can ignore the kind of magic and only look at the name of the member
if (member == "coinbase")
m_context << eth::Instruction::COINBASE;
else if (member == "timestamp")
m_context << eth::Instruction::TIMESTAMP;
else if (member == "difficulty")
m_context << eth::Instruction::DIFFICULTY;
else if (member == "number")
m_context << eth::Instruction::NUMBER;
else if (member == "gaslimit")
m_context << eth::Instruction::GASLIMIT;
else if (member == "sender")
m_context << eth::Instruction::CALLER;
else if (member == "value")
m_context << eth::Instruction::CALLVALUE;
else if (member == "origin")
m_context << eth::Instruction::ORIGIN;
else if (member == "gas")
m_context << eth::Instruction::GAS;
else if (member == "gasprice")
m_context << eth::Instruction::GASPRICE;
else
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown magic member."));
break;
case Type::Category::STRUCT:
{
StructType const& type = dynamic_cast<StructType const&>(*_memberAccess.getExpression().getType());
m_context << type.getStorageOffsetOfMember(member) << eth::Instruction::ADD;
m_currentLValue = LValue(m_context, LValue::STORAGE, *_memberAccess.getType());
m_currentLValue.retrieveValueIfLValueNotRequested(_memberAccess);
break;
}
case Type::Category::TYPE:
{
TypeType const& type = dynamic_cast<TypeType const&>(*_memberAccess.getExpression().getType());
if (type.getMembers().getMemberType(member))
{
ContractDefinition const& contract = dynamic_cast<ContractType const&>(*type.getActualType())
.getContractDefinition();
for (ASTPointer<FunctionDefinition> const& function: contract.getDefinedFunctions())
if (function->getName() == member)
{
m_context << m_context.getFunctionEntryLabel(*function).pushTag();
return;
}
}
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid member access to " + type.toString()));
}
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Member access to unknown type."));
}
}
bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
{
_indexAccess.getBaseExpression().accept(*this);
TypePointer const& keyType = dynamic_cast<MappingType const&>(*_indexAccess.getBaseExpression().getType()).getKeyType();
unsigned length = appendExpressionCopyToMemory(*keyType, _indexAccess.getIndexExpression());
solAssert(length == 32, "Mapping key has to take 32 bytes in memory (for now).");
// @todo move this once we actually use memory
length += CompilerUtils(m_context).storeInMemory(length);
m_context << u256(length) << u256(0) << eth::Instruction::SHA3;
m_currentLValue = LValue(m_context, LValue::STORAGE, *_indexAccess.getType());
m_currentLValue.retrieveValueIfLValueNotRequested(_indexAccess);
return false;
}
void ExpressionCompiler::endVisit(Identifier const& _identifier)
{
Declaration const* declaration = _identifier.getReferencedDeclaration();
if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
{
if (magicVar->getType()->getCategory() == Type::Category::CONTRACT)
// "this" or "super"
if (!dynamic_cast<ContractType const&>(*magicVar->getType()).isSuper())
m_context << eth::Instruction::ADDRESS;
}
else if (FunctionDefinition const* functionDef = dynamic_cast<FunctionDefinition const*>(declaration))
m_context << m_context.getVirtualFunctionEntryLabel(*functionDef).pushTag();
else if (dynamic_cast<VariableDeclaration const*>(declaration))
{
m_currentLValue.fromIdentifier(_identifier, *declaration);
m_currentLValue.retrieveValueIfLValueNotRequested(_identifier);
}
else if (dynamic_cast<ContractDefinition const*>(declaration))
{
// no-op
}
else if (dynamic_cast<EventDefinition const*>(declaration))
{
// no-op
}
else
{
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Identifier type not expected in expression context."));
}
}
void ExpressionCompiler::endVisit(Literal const& _literal)
{
switch (_literal.getType()->getCategory())
{
case Type::Category::INTEGER_CONSTANT:
case Type::Category::BOOL:
case Type::Category::STRING:
m_context << _literal.getType()->literalValue(&_literal);
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Only integer, boolean and string literals implemented for now."));
}
}
void ExpressionCompiler::appendAndOrOperatorCode(BinaryOperation const& _binaryOperation)
{
Token::Value const c_op = _binaryOperation.getOperator();
solAssert(c_op == Token::OR || c_op == Token::AND, "");
_binaryOperation.getLeftExpression().accept(*this);
m_context << eth::Instruction::DUP1;
if (c_op == Token::AND)
m_context << eth::Instruction::ISZERO;
eth::AssemblyItem endLabel = m_context.appendConditionalJump();
m_context << eth::Instruction::POP;
_binaryOperation.getRightExpression().accept(*this);
m_context << endLabel;
}
void ExpressionCompiler::appendCompareOperatorCode(Token::Value _operator, Type const& _type)
{
if (_operator == Token::EQ || _operator == Token::NE)
{
m_context << eth::Instruction::EQ;
if (_operator == Token::NE)
m_context << eth::Instruction::ISZERO;
}
else
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
bool const c_isSigned = type.isSigned();
switch (_operator)
{
case Token::GTE:
m_context << (c_isSigned ? eth::Instruction::SLT : eth::Instruction::LT)
<< eth::Instruction::ISZERO;
break;
case Token::LTE:
m_context << (c_isSigned ? eth::Instruction::SGT : eth::Instruction::GT)
<< eth::Instruction::ISZERO;
break;
case Token::GT:
m_context << (c_isSigned ? eth::Instruction::SGT : eth::Instruction::GT);
break;
case Token::LT:
m_context << (c_isSigned ? eth::Instruction::SLT : eth::Instruction::LT);
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown comparison operator."));
}
}
}
void ExpressionCompiler::appendOrdinaryBinaryOperatorCode(Token::Value _operator, Type const& _type)
{
if (Token::isArithmeticOp(_operator))
appendArithmeticOperatorCode(_operator, _type);
else if (Token::isBitOp(_operator))
appendBitOperatorCode(_operator);
else if (Token::isShiftOp(_operator))
appendShiftOperatorCode(_operator);
else
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown binary operator."));
}
void ExpressionCompiler::appendArithmeticOperatorCode(Token::Value _operator, Type const& _type)
{
IntegerType const& type = dynamic_cast<IntegerType const&>(_type);
bool const c_isSigned = type.isSigned();
switch (_operator)
{
case Token::ADD:
m_context << eth::Instruction::ADD;
break;
case Token::SUB:
m_context << eth::Instruction::SUB;
break;
case Token::MUL:
m_context << eth::Instruction::MUL;
break;
case Token::DIV:
m_context << (c_isSigned ? eth::Instruction::SDIV : eth::Instruction::DIV);
break;
case Token::MOD:
m_context << (c_isSigned ? eth::Instruction::SMOD : eth::Instruction::MOD);
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown arithmetic operator."));
}
}
void ExpressionCompiler::appendBitOperatorCode(Token::Value _operator)
{
switch (_operator)
{
case Token::BIT_OR:
m_context << eth::Instruction::OR;
break;
case Token::BIT_AND:
m_context << eth::Instruction::AND;
break;
case Token::BIT_XOR:
m_context << eth::Instruction::XOR;
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown bit operator."));
}
}
void ExpressionCompiler::appendShiftOperatorCode(Token::Value _operator)
{
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Shift operators not yet implemented."));
switch (_operator)
{
case Token::SHL:
break;
case Token::SAR:
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown shift operator."));
}
}
void ExpressionCompiler::appendTypeConversion(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded)
{
// For a type extension, we need to remove all higher-order bits that we might have ignored in
// previous operations.
// @todo: store in the AST whether the operand might have "dirty" higher order bits
if (_typeOnStack == _targetType && !_cleanupNeeded)
return;
Type::Category stackTypeCategory = _typeOnStack.getCategory();
Type::Category targetTypeCategory = _targetType.getCategory();
if (stackTypeCategory == Type::Category::STRING)
{
if (targetTypeCategory == Type::Category::INTEGER)
{
// conversion from string to hash. no need to clean the high bit
// only to shift right because of opposite alignment
IntegerType const& targetIntegerType = dynamic_cast<IntegerType const&>(_targetType);
StaticStringType const& typeOnStack = dynamic_cast<StaticStringType const&>(_typeOnStack);
solAssert(targetIntegerType.isHash(), "Only conversion between String and Hash is allowed.");
solAssert(targetIntegerType.getNumBits() == typeOnStack.getNumBytes() * 8, "The size should be the same.");
m_context << (u256(1) << (256 - typeOnStack.getNumBytes() * 8)) << eth::Instruction::SWAP1 << eth::Instruction::DIV;
}
else
{
solAssert(targetTypeCategory == Type::Category::STRING, "Invalid type conversion requested.");
// nothing to do, strings are high-order-bit-aligned
//@todo clear lower-order bytes if we allow explicit conversion to shorter strings
}
}
else if (stackTypeCategory == Type::Category::INTEGER || stackTypeCategory == Type::Category::CONTRACT ||
stackTypeCategory == Type::Category::INTEGER_CONSTANT)
{
if (targetTypeCategory == Type::Category::STRING && stackTypeCategory == Type::Category::INTEGER)
{
// conversion from hash to string. no need to clean the high bit
// only to shift left because of opposite alignment
StaticStringType const& targetStringType = dynamic_cast<StaticStringType const&>(_targetType);
IntegerType const& typeOnStack = dynamic_cast<IntegerType const&>(_typeOnStack);
solAssert(typeOnStack.isHash(), "Only conversion between String and Hash is allowed.");
solAssert(typeOnStack.getNumBits() == targetStringType.getNumBytes() * 8, "The size should be the same.");
m_context << (u256(1) << (256 - typeOnStack.getNumBits())) << eth::Instruction::MUL;
}
else
{
solAssert(targetTypeCategory == Type::Category::INTEGER || targetTypeCategory == Type::Category::CONTRACT, "");
IntegerType addressType(0, IntegerType::Modifier::ADDRESS);
IntegerType const& targetType = targetTypeCategory == Type::Category::INTEGER
? dynamic_cast<IntegerType const&>(_targetType) : addressType;
if (stackTypeCategory == Type::Category::INTEGER_CONSTANT)
{
IntegerConstantType const& constType = dynamic_cast<IntegerConstantType const&>(_typeOnStack);
// We know that the stack is clean, we only have to clean for a narrowing conversion
// where cleanup is forced.
if (targetType.getNumBits() < constType.getIntegerType()->getNumBits() && _cleanupNeeded)
appendHighBitsCleanup(targetType);
}
else
{
IntegerType const& typeOnStack = stackTypeCategory == Type::Category::INTEGER
? dynamic_cast<IntegerType const&>(_typeOnStack) : addressType;
// Widening: clean up according to source type width
// Non-widening and force: clean up according to target type bits
if (targetType.getNumBits() > typeOnStack.getNumBits())
appendHighBitsCleanup(typeOnStack);
else if (_cleanupNeeded)
appendHighBitsCleanup(targetType);
}
}
}
else if (_typeOnStack != _targetType)
// All other types should not be convertible to non-equal types.
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid type conversion requested."));
}
void ExpressionCompiler::appendHighBitsCleanup(IntegerType const& _typeOnStack)
{
if (_typeOnStack.getNumBits() == 256)
return;
else if (_typeOnStack.isSigned())
m_context << u256(_typeOnStack.getNumBits() / 8 - 1) << eth::Instruction::SIGNEXTEND;
else
m_context << ((u256(1) << _typeOnStack.getNumBits()) - 1) << eth::Instruction::AND;
}
void ExpressionCompiler::appendExternalFunctionCall(FunctionType const& _functionType,
vector<ASTPointer<Expression const>> const& _arguments,
bool bare)
{
solAssert(_arguments.size() == _functionType.getParameterTypes().size(), "");
// Assumed stack content here:
// <stack top>
// value [if _functionType.valueSet()]
// gas [if _functionType.gasSet()]
// function identifier [unless bare]
// contract address
unsigned gasValueSize = (_functionType.gasSet() ? 1 : 0) + (_functionType.valueSet() ? 1 : 0);
unsigned contractStackPos = m_context.currentToBaseStackOffset(1 + gasValueSize + (bare ? 0 : 1));
unsigned gasStackPos = m_context.currentToBaseStackOffset(gasValueSize);
unsigned valueStackPos = m_context.currentToBaseStackOffset(1);
if (!bare)
{
// copy function identifier
m_context << eth::dupInstruction(gasValueSize + 1);
CompilerUtils(m_context).storeInMemory(0, CompilerUtils::dataStartOffset);
}
// reserve space for the function identifier
unsigned dataOffset = bare ? 0 : CompilerUtils::dataStartOffset;
dataOffset += appendArgumentCopyToMemory(_functionType.getParameterTypes(), _arguments, dataOffset);
//@todo only return the first return value for now
Type const* firstType = _functionType.getReturnParameterTypes().empty() ? nullptr :
_functionType.getReturnParameterTypes().front().get();
unsigned retSize = firstType ? CompilerUtils::getPaddedSize(firstType->getCalldataEncodedSize()) : 0;
// CALL arguments: outSize, outOff, inSize, inOff, value, addr, gas (stack top)
m_context << u256(retSize) << u256(0) << u256(dataOffset) << u256(0);
if (_functionType.valueSet())
m_context << eth::dupInstruction(m_context.baseToCurrentStackOffset(valueStackPos));
else
m_context << u256(0);
m_context << eth::dupInstruction(m_context.baseToCurrentStackOffset(contractStackPos));
if (_functionType.gasSet())
m_context << eth::dupInstruction(m_context.baseToCurrentStackOffset(gasStackPos));
else
// send all gas except for the 21 needed to execute "SUB" and "CALL"
m_context << u256(21) << eth::Instruction::GAS << eth::Instruction::SUB;
m_context << eth::Instruction::CALL
<< eth::Instruction::POP; // @todo do not ignore failure indicator
if (_functionType.valueSet())
m_context << eth::Instruction::POP;
if (_functionType.gasSet())
m_context << eth::Instruction::POP;
if (!bare)
m_context << eth::Instruction::POP;
m_context << eth::Instruction::POP; // pop contract address
if (retSize > 0)
{
bool const c_leftAligned = firstType->getCategory() == Type::Category::STRING;
CompilerUtils(m_context).loadFromMemory(0, retSize, c_leftAligned, false, true);
}
}
unsigned ExpressionCompiler::appendArgumentCopyToMemory(TypePointers const& _types,
vector<ASTPointer<Expression const>> const& _arguments,
unsigned _memoryOffset)
{
unsigned length = 0;
for (unsigned i = 0; i < _arguments.size(); ++i)
length += appendExpressionCopyToMemory(*_types[i], *_arguments[i], _memoryOffset + length);
return length;
}
unsigned ExpressionCompiler::appendExpressionCopyToMemory(Type const& _expectedType,
Expression const& _expression, unsigned _memoryOffset)
{
_expression.accept(*this);
appendTypeConversion(*_expression.getType(), _expectedType, true);
unsigned const c_numBytes = CompilerUtils::getPaddedSize(_expectedType.getCalldataEncodedSize());
if (c_numBytes == 0 || c_numBytes > 32)
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Type " + _expectedType.toString() + " not yet supported."));
bool const c_leftAligned = _expectedType.getCategory() == Type::Category::STRING;
bool const c_padToWords = true;
return CompilerUtils(m_context).storeInMemory(_memoryOffset, c_numBytes, c_leftAligned, c_padToWords);
}
void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const& _varDecl)
{
m_currentLValue.fromStateVariable(_varDecl, _varDecl.getType());
solAssert(m_currentLValue.isInStorage(), "");
m_currentLValue.retrieveValue(_varDecl.getType(), Location(), true);
}
ExpressionCompiler::LValue::LValue(CompilerContext& _compilerContext, LValueType _type, Type const& _dataType,
unsigned _baseStackOffset):
m_context(&_compilerContext), m_type(_type), m_baseStackOffset(_baseStackOffset)
{
//@todo change the type cast for arrays
solAssert(_dataType.getStorageSize() <= numeric_limits<unsigned>::max(), "The storage size of " +_dataType.toString() + " should fit in unsigned");
if (m_type == STORAGE)
m_size = unsigned(_dataType.getStorageSize());
else
m_size = unsigned(_dataType.getSizeOnStack());
}
void ExpressionCompiler::LValue::retrieveValue(TypePointer const& _type, Location const& _location, bool _remove) const
{
switch (m_type)
{
case STACK:
{
unsigned stackPos = m_context->baseToCurrentStackOffset(unsigned(m_baseStackOffset));
if (stackPos >= 15) //@todo correct this by fetching earlier or moving to memory
BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(_location)
<< errinfo_comment("Stack too deep."));
for (unsigned i = 0; i < m_size; ++i)
*m_context << eth::dupInstruction(stackPos + 1);
break;
}
case STORAGE:
retrieveValueFromStorage(_type, _remove);
break;
case MEMORY:
if (!_type->isValueType())
break; // no distinction between value and reference for non-value types
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_location)
<< errinfo_comment("Location type not yet implemented."));
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_location)
<< errinfo_comment("Unsupported location type."));
break;
}
}
void ExpressionCompiler::LValue::retrieveValueFromStorage(TypePointer const& _type, bool _remove) const
{
if (!_type->isValueType())
return; // no distinction between value and reference for non-value types
if (!_remove)
*m_context << eth::Instruction::DUP1;
if (m_size == 1)
*m_context << eth::Instruction::SLOAD;
else
for (unsigned i = 0; i < m_size; ++i)
{
*m_context << eth::Instruction::DUP1 << eth::Instruction::SLOAD << eth::Instruction::SWAP1;
if (i + 1 < m_size)
*m_context << u256(1) << eth::Instruction::ADD;
else
*m_context << eth::Instruction::POP;
}
}
void ExpressionCompiler::LValue::storeValue(Expression const& _expression, bool _move) const
{
switch (m_type)
{
case STACK:
{
unsigned stackDiff = m_context->baseToCurrentStackOffset(unsigned(m_baseStackOffset)) - m_size + 1;
if (stackDiff > 16)
BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Stack too deep."));
else if (stackDiff > 0)
for (unsigned i = 0; i < m_size; ++i)
*m_context << eth::swapInstruction(stackDiff) << eth::Instruction::POP;
if (!_move)
retrieveValue(_expression.getType(), _expression.getLocation());
break;
}
case LValue::STORAGE:
if (!_expression.getType()->isValueType())
break; // no distinction between value and reference for non-value types
// stack layout: value value ... value ref
if (!_move) // copy values
{
if (m_size + 1 > 16)
BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Stack too deep."));
for (unsigned i = 0; i < m_size; ++i)
*m_context << eth::dupInstruction(m_size + 1) << eth::Instruction::SWAP1;
}
if (m_size > 0) // store high index value first
*m_context << u256(m_size - 1) << eth::Instruction::ADD;
for (unsigned i = 0; i < m_size; ++i)
{
if (i + 1 >= m_size)
*m_context << eth::Instruction::SSTORE;
else
// v v ... v v r+x
*m_context << eth::Instruction::SWAP1 << eth::Instruction::DUP2
<< eth::Instruction::SSTORE
<< u256(1) << eth::Instruction::SWAP1 << eth::Instruction::SUB;
}
break;
case LValue::MEMORY:
if (!_expression.getType()->isValueType())
break; // no distinction between value and reference for non-value types
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Location type not yet implemented."));
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Unsupported location type."));
break;
}
}
void ExpressionCompiler::LValue::setToZero(Expression const& _expression) const
{
switch (m_type)
{
case STACK:
{
unsigned stackDiff = m_context->baseToCurrentStackOffset(unsigned(m_baseStackOffset));
if (stackDiff > 16)
BOOST_THROW_EXCEPTION(CompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Stack too deep."));
solAssert(stackDiff >= m_size - 1, "");
for (unsigned i = 0; i < m_size; ++i)
*m_context << u256(0) << eth::swapInstruction(stackDiff + 1 - i)
<< eth::Instruction::POP;
break;
}
case LValue::STORAGE:
if (m_size == 0)
*m_context << eth::Instruction::POP;
for (unsigned i = 0; i < m_size; ++i)
{
if (i + 1 >= m_size)
*m_context << u256(0) << eth::Instruction::SWAP1 << eth::Instruction::SSTORE;
else
*m_context << u256(0) << eth::Instruction::DUP2 << eth::Instruction::SSTORE
<< u256(1) << eth::Instruction::ADD;
}
break;
case LValue::MEMORY:
if (!_expression.getType()->isValueType())
break; // no distinction between value and reference for non-value types
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Location type not yet implemented."));
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_expression.getLocation())
<< errinfo_comment("Unsupported location type."));
break;
}
}
void ExpressionCompiler::LValue::retrieveValueIfLValueNotRequested(Expression const& _expression)
{
if (!_expression.lvalueRequested())
{
retrieveValue(_expression.getType(), _expression.getLocation(), true);
reset();
}
}
void ExpressionCompiler::LValue::fromStateVariable(Declaration const& _varDecl, TypePointer const& _type)
{
m_type = STORAGE;
solAssert(_type->getStorageSize() <= numeric_limits<unsigned>::max(), "The storage size of " + _type->toString() + " should fit in an unsigned");
*m_context << m_context->getStorageLocationOfVariable(_varDecl);
m_size = unsigned(_type->getStorageSize());
}
void ExpressionCompiler::LValue::fromIdentifier(Identifier const& _identifier, Declaration const& _declaration)
{
if (m_context->isLocalVariable(&_declaration))
{
m_type = STACK;
m_size = _identifier.getType()->getSizeOnStack();
m_baseStackOffset = m_context->getBaseStackOffsetOfVariable(_declaration);
}
else if (m_context->isStateVariable(&_declaration))
{
fromStateVariable(_declaration, _identifier.getType());
}
else
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_sourceLocation(_identifier.getLocation())
<< errinfo_comment("Identifier type not supported or identifier not found."));
}
}
}