solidity/libsolidity/ExpressionCompiler.cpp

1297 lines
43 KiB
C++

/*
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 <boost/range/adaptor/reversed.hpp>
#include <libevmcore/Params.h>
#include <libdevcore/Common.h>
#include <libdevcore/SHA3.h>
#include <libsolidity/AST.h>
#include <libsolidity/ExpressionCompiler.h>
#include <libsolidity/CompilerContext.h>
#include <libsolidity/CompilerUtils.h>
#include <libsolidity/LValue.h>
using namespace std;
namespace dev
{
namespace solidity
{
void ExpressionCompiler::compile(Expression const& _expression)
{
_expression.accept(*this);
}
void ExpressionCompiler::appendStateVariableInitialization(VariableDeclaration const& _varDecl)
{
if (!_varDecl.value())
return;
TypePointer type = _varDecl.value()->type();
solAssert(!!type, "Type information not available.");
CompilerContext::LocationSetter locationSetter(m_context, _varDecl);
_varDecl.value()->accept(*this);
if (_varDecl.type()->dataStoredIn(DataLocation::Storage))
{
// reference type, only convert value to mobile type and do final conversion in storeValue.
utils().convertType(*type, *type->mobileType());
type = type->mobileType();
}
else
{
utils().convertType(*type, *_varDecl.type());
type = _varDecl.type();
}
StorageItem(m_context, _varDecl).storeValue(*type, _varDecl.location(), true);
}
void ExpressionCompiler::appendConstStateVariableAccessor(VariableDeclaration const& _varDecl)
{
solAssert(_varDecl.isConstant(), "");
_varDecl.value()->accept(*this);
utils().convertType(*_varDecl.value()->type(), *_varDecl.type());
// append return
m_context << eth::dupInstruction(_varDecl.type()->sizeOnStack() + 1);
m_context.appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
}
void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const& _varDecl)
{
solAssert(!_varDecl.isConstant(), "");
CompilerContext::LocationSetter locationSetter(m_context, _varDecl);
FunctionType accessorType(_varDecl);
TypePointers const& paramTypes = accessorType.parameterTypes();
// retrieve the position of the variable
auto const& location = m_context.storageLocationOfVariable(_varDecl);
m_context << location.first << u256(location.second);
TypePointer returnType = _varDecl.type();
for (size_t i = 0; i < paramTypes.size(); ++i)
{
if (auto mappingType = dynamic_cast<MappingType const*>(returnType.get()))
{
solAssert(CompilerUtils::freeMemoryPointer >= 0x40, "");
solAssert(
!paramTypes[i]->isDynamicallySized(),
"Accessors for mapping with dynamically-sized keys not yet implemented."
);
// pop offset
m_context << eth::Instruction::POP;
// move storage offset to memory.
utils().storeInMemory(32);
// move key to memory.
utils().copyToStackTop(paramTypes.size() - i, 1);
utils().storeInMemory(0);
m_context << u256(64) << u256(0) << eth::Instruction::SHA3;
// push offset
m_context << u256(0);
returnType = mappingType->valueType();
}
else if (auto arrayType = dynamic_cast<ArrayType const*>(returnType.get()))
{
// pop offset
m_context << eth::Instruction::POP;
utils().copyToStackTop(paramTypes.size() - i + 1, 1);
ArrayUtils(m_context).accessIndex(*arrayType);
returnType = arrayType->baseType();
}
else
solAssert(false, "Index access is allowed only for \"mapping\" and \"array\" types.");
}
// remove index arguments.
if (paramTypes.size() == 1)
m_context << eth::Instruction::SWAP2 << eth::Instruction::POP << eth::Instruction::SWAP1;
else if (paramTypes.size() >= 2)
{
m_context << eth::swapInstruction(paramTypes.size());
m_context << eth::Instruction::POP;
m_context << eth::swapInstruction(paramTypes.size());
utils().popStackSlots(paramTypes.size() - 1);
}
unsigned retSizeOnStack = 0;
solAssert(accessorType.returnParameterTypes().size() >= 1, "");
auto const& returnTypes = accessorType.returnParameterTypes();
if (StructType const* structType = dynamic_cast<StructType const*>(returnType.get()))
{
// remove offset
m_context << eth::Instruction::POP;
auto const& names = accessorType.returnParameterNames();
// struct
for (size_t i = 0; i < names.size(); ++i)
{
if (returnTypes[i]->category() == Type::Category::Mapping)
continue;
if (auto arrayType = dynamic_cast<ArrayType const*>(returnTypes[i].get()))
if (!arrayType->isByteArray())
continue;
pair<u256, unsigned> const& offsets = structType->storageOffsetsOfMember(names[i]);
m_context << eth::Instruction::DUP1 << u256(offsets.first) << eth::Instruction::ADD << u256(offsets.second);
TypePointer memberType = structType->memberType(names[i]);
StorageItem(m_context, *memberType).retrieveValue(SourceLocation(), true);
utils().convertType(*memberType, *returnTypes[i]);
utils().moveToStackTop(returnTypes[i]->sizeOnStack());
retSizeOnStack += returnTypes[i]->sizeOnStack();
}
// remove slot
m_context << eth::Instruction::POP;
}
else
{
// simple value or array
solAssert(returnTypes.size() == 1, "");
StorageItem(m_context, *returnType).retrieveValue(SourceLocation(), true);
utils().convertType(*returnType, *returnTypes.front());
retSizeOnStack = returnTypes.front()->sizeOnStack();
}
solAssert(retSizeOnStack == utils().sizeOnStack(returnTypes), "");
solAssert(retSizeOnStack <= 15, "Stack is too deep.");
m_context << eth::dupInstruction(retSizeOnStack + 1);
m_context.appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
}
bool ExpressionCompiler::visit(Assignment const& _assignment)
{
CompilerContext::LocationSetter locationSetter(m_context, _assignment);
_assignment.rightHandSide().accept(*this);
TypePointer type = _assignment.rightHandSide().type();
if (!_assignment.type()->dataStoredIn(DataLocation::Storage))
{
utils().convertType(*type, *_assignment.type());
type = _assignment.type();
}
else
{
utils().convertType(*type, *type->mobileType());
type = type->mobileType();
}
_assignment.leftHandSide().accept(*this);
solAssert(!!m_currentLValue, "LValue not retrieved.");
Token::Value op = _assignment.assignmentOperator();
if (op != Token::Assign) // compound assignment
{
solAssert(_assignment.type()->isValueType(), "Compound operators not implemented for non-value types.");
unsigned lvalueSize = m_currentLValue->sizeOnStack();
unsigned itemSize = _assignment.type()->sizeOnStack();
if (lvalueSize > 0)
{
utils().copyToStackTop(lvalueSize + itemSize, itemSize);
utils().copyToStackTop(itemSize + lvalueSize, lvalueSize);
// value lvalue_ref value lvalue_ref
}
m_currentLValue->retrieveValue(_assignment.location(), true);
appendOrdinaryBinaryOperatorCode(Token::AssignmentToBinaryOp(op), *_assignment.type());
if (lvalueSize > 0)
{
solAssert(itemSize + lvalueSize <= 16, "Stack too deep, try removing local variables.");
// value [lvalue_ref] updated_value
for (unsigned i = 0; i < itemSize; ++i)
m_context << eth::swapInstruction(itemSize + lvalueSize) << eth::Instruction::POP;
}
}
m_currentLValue->storeValue(*type, _assignment.location());
m_currentLValue.reset();
return false;
}
bool ExpressionCompiler::visit(UnaryOperation const& _unaryOperation)
{
CompilerContext::LocationSetter locationSetter(m_context, _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.type()->category() == Type::Category::IntegerConstant)
{
m_context << _unaryOperation.type()->literalValue(nullptr);
return false;
}
_unaryOperation.subExpression().accept(*this);
switch (_unaryOperation.getOperator())
{
case Token::Not: // !
m_context << eth::Instruction::ISZERO;
break;
case Token::BitNot: // ~
m_context << eth::Instruction::NOT;
break;
case Token::After: // after
m_context << eth::Instruction::TIMESTAMP << eth::Instruction::ADD;
break;
case Token::Delete: // delete
solAssert(!!m_currentLValue, "LValue not retrieved.");
m_currentLValue->setToZero(_unaryOperation.location());
m_currentLValue.reset();
break;
case Token::Inc: // ++ (pre- or postfix)
case Token::Dec: // -- (pre- or postfix)
solAssert(!!m_currentLValue, "LValue not retrieved.");
m_currentLValue->retrieveValue(_unaryOperation.location());
if (!_unaryOperation.isPrefixOperation())
{
// store value for later
solAssert(_unaryOperation.type()->sizeOnStack() == 1, "Stack size != 1 not implemented.");
m_context << eth::Instruction::DUP1;
if (m_currentLValue->sizeOnStack() > 0)
for (unsigned i = 1 + m_currentLValue->sizeOnStack(); i > 0; --i)
m_context << eth::swapInstruction(i);
}
m_context << u256(1);
if (_unaryOperation.getOperator() == Token::Inc)
m_context << eth::Instruction::ADD;
else
m_context << eth::Instruction::SWAP1 << eth::Instruction::SUB;
// Stack for prefix: [ref...] (*ref)+-1
// Stack for postfix: *ref [ref...] (*ref)+-1
for (unsigned i = m_currentLValue->sizeOnStack(); i > 0; --i)
m_context << eth::swapInstruction(i);
m_currentLValue->storeValue(
*_unaryOperation.type(), _unaryOperation.location(),
!_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)
{
CompilerContext::LocationSetter locationSetter(m_context, _binaryOperation);
Expression const& leftExpression = _binaryOperation.leftExpression();
Expression const& rightExpression = _binaryOperation.rightExpression();
Type const& commonType = _binaryOperation.commonType();
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.category() == Type::Category::IntegerConstant)
m_context << commonType.literalValue(nullptr);
else
{
bool cleanupNeeded = commonType.category() == 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.type()->category() == Type::Category::IntegerConstant;
};
bool swap = m_optimize && Token::isCommutativeOp(c_op) && isLiteral(rightExpression) && !isLiteral(leftExpression);
if (swap)
{
leftExpression.accept(*this);
utils().convertType(*leftExpression.type(), commonType, cleanupNeeded);
rightExpression.accept(*this);
utils().convertType(*rightExpression.type(), commonType, cleanupNeeded);
}
else
{
rightExpression.accept(*this);
utils().convertType(*rightExpression.type(), commonType, cleanupNeeded);
leftExpression.accept(*this);
utils().convertType(*leftExpression.type(), 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)
{
CompilerContext::LocationSetter locationSetter(m_context, _functionCall);
using Location = FunctionType::Location;
if (_functionCall.isTypeConversion())
{
solAssert(_functionCall.arguments().size() == 1, "");
solAssert(_functionCall.names().empty(), "");
Expression const& firstArgument = *_functionCall.arguments().front();
firstArgument.accept(*this);
utils().convertType(*firstArgument.type(), *_functionCall.type());
return false;
}
FunctionTypePointer functionType;
if (_functionCall.isStructConstructorCall())
{
auto const& type = dynamic_cast<TypeType const&>(*_functionCall.expression().type());
auto const& structType = dynamic_cast<StructType const&>(*type.actualType());
functionType = structType.constructorType();
}
else
functionType = dynamic_pointer_cast<FunctionType const>(_functionCall.expression().type());
TypePointers const& parameterTypes = functionType->parameterTypes();
vector<ASTPointer<Expression const>> const& callArguments = _functionCall.arguments();
vector<ASTPointer<ASTString>> const& callArgumentNames = _functionCall.names();
if (!functionType->takesArbitraryParameters())
solAssert(callArguments.size() == parameterTypes.size(), "");
vector<ASTPointer<Expression const>> arguments;
if (callArgumentNames.empty())
// normal arguments
arguments = callArguments;
else
// named arguments
for (auto const& parameterName: functionType->parameterNames())
{
bool found = false;
for (size_t j = 0; j < callArgumentNames.size() && !found; j++)
if ((found = (parameterName == *callArgumentNames[j])))
// we found the actual parameter position
arguments.push_back(callArguments[j]);
solAssert(found, "");
}
if (_functionCall.isStructConstructorCall())
{
TypeType const& type = dynamic_cast<TypeType const&>(*_functionCall.expression().type());
auto const& structType = dynamic_cast<StructType const&>(*type.actualType());
m_context << u256(max(32u, structType.calldataEncodedSize(true)));
utils().allocateMemory();
m_context << eth::Instruction::DUP1;
for (unsigned i = 0; i < arguments.size(); ++i)
{
arguments[i]->accept(*this);
utils().convertType(*arguments[i]->type(), *functionType->parameterTypes()[i]);
utils().storeInMemoryDynamic(*functionType->parameterTypes()[i]);
}
m_context << eth::Instruction::POP;
}
else
{
FunctionType const& function = *functionType;
switch (function.location())
{
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);
utils().convertType(*arguments[i]->type(), *function.parameterTypes()[i]);
}
_functionCall.expression().accept(*this);
m_context.appendJump(eth::AssemblyItem::JumpType::IntoFunction);
m_context << returnLabel;
unsigned returnParametersSize = CompilerUtils::sizeOnStack(function.returnParameterTypes());
// callee adds return parameters, but removes arguments and return label
m_context.adjustStackOffset(returnParametersSize - CompilerUtils::sizeOnStack(function.parameterTypes()) - 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.returnParameterTypes().size(); ++i)
utils().popStackElement(*function.returnParameterTypes()[i]);
break;
}
case Location::External:
case Location::CallCode:
case Location::Bare:
case Location::BareCallCode:
_functionCall.expression().accept(*this);
appendExternalFunctionCall(function, arguments);
break;
case Location::Creation:
{
_functionCall.expression().accept(*this);
solAssert(!function.gasSet(), "Gas limit set for contract creation.");
solAssert(function.returnParameterTypes().size() == 1, "");
TypePointers argumentTypes;
for (auto const& arg: arguments)
{
arg->accept(*this);
argumentTypes.push_back(arg->type());
}
ContractDefinition const& contract =
dynamic_cast<ContractType const&>(*function.returnParameterTypes().front()).contractDefinition();
// copy the contract's code into memory
eth::Assembly const& assembly = m_context.compiledContract(contract);
utils().fetchFreeMemoryPointer();
// 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;
utils().encodeToMemory(argumentTypes, function.parameterTypes());
// now on stack: memory_end_ptr
// need: size, offset, endowment
utils().toSizeAfterFreeMemoryPointer();
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::SetGas:
{
// stack layout: contract_address function_id [gas] [value]
_functionCall.expression().accept(*this);
arguments.front()->accept(*this);
utils().convertType(*arguments.front()->type(), 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::SetValue:
// stack layout: contract_address function_id [gas] [value]
_functionCall.expression().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.expression().accept(*this);
m_context << u256(0); // do not send gas (there still is the stipend)
arguments.front()->accept(*this);
utils().convertType(
*arguments.front()->type(),
*function.parameterTypes().front(), true
);
appendExternalFunctionCall(
FunctionType(
TypePointers{},
TypePointers{},
strings(),
strings(),
Location::Bare,
false,
nullptr,
true,
true
),
{}
);
break;
case Location::Suicide:
arguments.front()->accept(*this);
utils().convertType(*arguments.front()->type(), *function.parameterTypes().front(), true);
m_context << eth::Instruction::SUICIDE;
break;
case Location::SHA3:
{
TypePointers argumentTypes;
for (auto const& arg: arguments)
{
arg->accept(*this);
argumentTypes.push_back(arg->type());
}
utils().fetchFreeMemoryPointer();
utils().encodeToMemory(argumentTypes, TypePointers(), function.padArguments(), true);
utils().toSizeAfterFreeMemoryPointer();
m_context << eth::Instruction::SHA3;
break;
}
case Location::Log0:
case Location::Log1:
case Location::Log2:
case Location::Log3:
case Location::Log4:
{
unsigned logNumber = int(function.location()) - int(Location::Log0);
for (unsigned arg = logNumber; arg > 0; --arg)
{
arguments[arg]->accept(*this);
utils().convertType(*arguments[arg]->type(), *function.parameterTypes()[arg], true);
}
arguments.front()->accept(*this);
utils().fetchFreeMemoryPointer();
utils().encodeToMemory(
{arguments.front()->type()},
{function.parameterTypes().front()},
false,
true);
utils().toSizeAfterFreeMemoryPointer();
m_context << eth::logInstruction(logNumber);
break;
}
case Location::Event:
{
_functionCall.expression().accept(*this);
auto const& event = dynamic_cast<EventDefinition const&>(function.declaration());
unsigned numIndexed = 0;
// All indexed arguments go to the stack
for (unsigned arg = arguments.size(); arg > 0; --arg)
if (event.parameters()[arg - 1]->isIndexed())
{
++numIndexed;
arguments[arg - 1]->accept(*this);
utils().convertType(
*arguments[arg - 1]->type(),
*function.parameterTypes()[arg - 1],
true
);
}
if (!event.isAnonymous())
{
m_context << u256(h256::Arith(dev::sha3(function.externalSignature(event.name()))));
++numIndexed;
}
solAssert(numIndexed <= 4, "Too many indexed arguments.");
// Copy all non-indexed arguments to memory (data)
// Memory position is only a hack and should be removed once we have free memory pointer.
TypePointers nonIndexedArgTypes;
TypePointers nonIndexedParamTypes;
for (unsigned arg = 0; arg < arguments.size(); ++arg)
if (!event.parameters()[arg]->isIndexed())
{
arguments[arg]->accept(*this);
nonIndexedArgTypes.push_back(arguments[arg]->type());
nonIndexedParamTypes.push_back(function.parameterTypes()[arg]);
}
utils().fetchFreeMemoryPointer();
utils().encodeToMemory(nonIndexedArgTypes, nonIndexedParamTypes);
// need: topic1 ... topicn memsize memstart
utils().toSizeAfterFreeMemoryPointer();
m_context << eth::logInstruction(numIndexed);
break;
}
case Location::BlockHash:
{
arguments[0]->accept(*this);
utils().convertType(*arguments[0]->type(), *function.parameterTypes()[0], true);
m_context << eth::Instruction::BLOCKHASH;
break;
}
case Location::ECRecover:
case Location::SHA256:
case Location::RIPEMD160:
{
_functionCall.expression().accept(*this);
static const map<Location, u256> contractAddresses{{Location::ECRecover, 1},
{Location::SHA256, 2},
{Location::RIPEMD160, 3}};
m_context << contractAddresses.find(function.location())->second;
for (unsigned i = function.sizeOnStack(); i > 0; --i)
m_context << eth::swapInstruction(i);
appendExternalFunctionCall(function, arguments);
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)
{
CompilerContext::LocationSetter locationSetter(m_context, _memberAccess);
ASTString const& member = _memberAccess.memberName();
switch (_memberAccess.expression().type()->category())
{
case Type::Category::Contract:
{
bool alsoSearchInteger = false;
ContractType const& type = dynamic_cast<ContractType const&>(*_memberAccess.expression().type());
if (type.isSuper())
{
solAssert(!!_memberAccess.referencedDeclaration(), "Referenced declaration not resolved.");
m_context << m_context.superFunctionEntryLabel(
dynamic_cast<FunctionDefinition const&>(*_memberAccess.referencedDeclaration()),
type.contractDefinition()
).pushTag();
}
else
{
// ordinary contract type
if (Declaration const* declaration = _memberAccess.referencedDeclaration())
{
u256 identifier;
if (auto const* variable = dynamic_cast<VariableDeclaration const*>(declaration))
identifier = FunctionType(*variable).externalIdentifier();
else if (auto const* function = dynamic_cast<FunctionDefinition const*>(declaration))
identifier = FunctionType(*function).externalIdentifier();
else
solAssert(false, "Contract member is neither variable nor function.");
utils().convertType(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")
{
utils().convertType(
*_memberAccess.expression().type(),
IntegerType(0, IntegerType::Modifier::Address),
true
);
m_context << eth::Instruction::BALANCE;
}
else if ((set<string>{"send", "call", "callcode"}).count(member))
utils().convertType(
*_memberAccess.expression().type(),
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.expression().type()->memberType(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 if (member == "data")
m_context << u256(0) << eth::Instruction::CALLDATASIZE;
else if (member == "sig")
m_context << u256(0) << eth::Instruction::CALLDATALOAD
<< (u256(0xffffffff) << (256 - 32)) << eth::Instruction::AND;
else
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown magic member."));
break;
case Type::Category::Struct:
{
StructType const& type = dynamic_cast<StructType const&>(*_memberAccess.expression().type());
switch (type.location())
{
case DataLocation::Storage:
{
pair<u256, unsigned> const& offsets = type.storageOffsetsOfMember(member);
m_context << offsets.first << eth::Instruction::ADD << u256(offsets.second);
setLValueToStorageItem(_memberAccess);
break;
}
case DataLocation::Memory:
{
m_context << type.memoryOffsetOfMember(member) << eth::Instruction::ADD;
setLValue<MemoryItem>(_memberAccess, *_memberAccess.type());
break;
}
default:
solAssert(false, "Illegal data location for struct.");
}
break;
}
case Type::Category::Enum:
{
EnumType const& type = dynamic_cast<EnumType const&>(*_memberAccess.expression().type());
m_context << type.memberValue(_memberAccess.memberName());
break;
}
case Type::Category::TypeType:
{
TypeType const& type = dynamic_cast<TypeType const&>(*_memberAccess.expression().type());
solAssert(
!type.members().membersByName(_memberAccess.memberName()).empty(),
"Invalid member access to " + type.toString(false)
);
if (dynamic_cast<ContractType const*>(type.actualType().get()))
{
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());
break;
}
case Type::Category::Array:
{
solAssert(member == "length", "Illegal array member.");
auto const& type = dynamic_cast<ArrayType const&>(*_memberAccess.expression().type());
if (!type.isDynamicallySized())
{
utils().popStackElement(type);
m_context << type.length();
}
else
switch (type.location())
{
case DataLocation::CallData:
m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
break;
case DataLocation::Storage:
setLValue<StorageArrayLength>(_memberAccess, type);
break;
case DataLocation::Memory:
m_context << eth::Instruction::MLOAD;
break;
}
break;
}
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Member access to unknown type."));
}
}
bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
{
CompilerContext::LocationSetter locationSetter(m_context, _indexAccess);
_indexAccess.baseExpression().accept(*this);
Type const& baseType = *_indexAccess.baseExpression().type();
if (baseType.category() == Type::Category::Mapping)
{
// stack: storage_base_ref
TypePointer keyType = dynamic_cast<MappingType const&>(baseType).keyType();
solAssert(_indexAccess.indexExpression(), "Index expression expected.");
if (keyType->isDynamicallySized())
{
_indexAccess.indexExpression()->accept(*this);
utils().fetchFreeMemoryPointer();
// stack: base index mem
// note: the following operations must not allocate memory!
utils().encodeToMemory(
TypePointers{_indexAccess.indexExpression()->type()},
TypePointers{keyType},
false,
true
);
m_context << eth::Instruction::SWAP1;
utils().storeInMemoryDynamic(IntegerType(256));
utils().toSizeAfterFreeMemoryPointer();
}
else
{
m_context << u256(0); // memory position
appendExpressionCopyToMemory(*keyType, *_indexAccess.indexExpression());
m_context << eth::Instruction::SWAP1;
solAssert(CompilerUtils::freeMemoryPointer >= 0x40, "");
utils().storeInMemoryDynamic(IntegerType(256));
m_context << u256(0);
}
m_context << eth::Instruction::SHA3;
m_context << u256(0);
setLValueToStorageItem(_indexAccess);
}
else if (baseType.category() == Type::Category::Array)
{
ArrayType const& arrayType = dynamic_cast<ArrayType const&>(baseType);
solAssert(_indexAccess.indexExpression(), "Index expression expected.");
_indexAccess.indexExpression()->accept(*this);
// stack layout: <base_ref> [<length>] <index>
ArrayUtils(m_context).accessIndex(arrayType);
switch (arrayType.location())
{
case DataLocation::Storage:
if (arrayType.isByteArray())
{
solAssert(!arrayType.isString(), "Index access to string is not allowed.");
setLValue<StorageByteArrayElement>(_indexAccess);
}
else
setLValueToStorageItem(_indexAccess);
break;
case DataLocation::Memory:
setLValue<MemoryItem>(_indexAccess, *_indexAccess.type(), !arrayType.isByteArray());
break;
case DataLocation::CallData:
//@todo if we implement this, the value in calldata has to be added to the base offset
solAssert(!arrayType.baseType()->isDynamicallySized(), "Nested arrays not yet implemented.");
if (arrayType.baseType()->isValueType())
CompilerUtils(m_context).loadFromMemoryDynamic(
*arrayType.baseType(),
true,
!arrayType.isByteArray(),
false
);
break;
}
}
else
solAssert(false, "Index access only allowed for mappings or arrays.");
return false;
}
void ExpressionCompiler::endVisit(Identifier const& _identifier)
{
CompilerContext::LocationSetter locationSetter(m_context, _identifier);
Declaration const* declaration = &_identifier.referencedDeclaration();
if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
{
switch (magicVar->type()->category())
{
case Type::Category::Contract:
// "this" or "super"
if (!dynamic_cast<ContractType const&>(*magicVar->type()).isSuper())
m_context << eth::Instruction::ADDRESS;
break;
case Type::Category::Integer:
// "now"
m_context << eth::Instruction::TIMESTAMP;
break;
default:
break;
}
}
else if (FunctionDefinition const* functionDef = dynamic_cast<FunctionDefinition const*>(declaration))
m_context << m_context.virtualFunctionEntryLabel(*functionDef).pushTag();
else if (auto variable = dynamic_cast<VariableDeclaration const*>(declaration))
{
if (!variable->isConstant())
setLValueFromDeclaration(*declaration, _identifier);
else
{
variable->value()->accept(*this);
utils().convertType(*variable->value()->type(), *variable->type());
}
}
else if (auto contract = dynamic_cast<ContractDefinition const*>(declaration))
{
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))
{
// no-op
}
else if (dynamic_cast<EnumDefinition const*>(declaration))
{
// no-op
}
else
{
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Identifier type not expected in expression context."));
}
}
void ExpressionCompiler::endVisit(Literal const& _literal)
{
CompilerContext::LocationSetter locationSetter(m_context, _literal);
TypePointer type = _literal.type();
switch (type->category())
{
case Type::Category::IntegerConstant:
case Type::Category::Bool:
m_context << type->literalValue(&_literal);
break;
case Type::Category::StringLiteral:
break; // will be done during conversion
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.leftExpression().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.rightExpression().accept(*this);
m_context << endLabel;
}
void ExpressionCompiler::appendCompareOperatorCode(Token::Value _operator, Type const& _type)
{
if (_operator == Token::Equal || _operator == Token::NotEqual)
{
m_context << eth::Instruction::EQ;
if (_operator == Token::NotEqual)
m_context << eth::Instruction::ISZERO;
}
else
{
bool isSigned = false;
if (auto type = dynamic_cast<IntegerType const*>(&_type))
isSigned = type->isSigned();
switch (_operator)
{
case Token::GreaterThanOrEqual:
m_context <<
(isSigned ? eth::Instruction::SLT : eth::Instruction::LT) <<
eth::Instruction::ISZERO;
break;
case Token::LessThanOrEqual:
m_context <<
(isSigned ? eth::Instruction::SGT : eth::Instruction::GT) <<
eth::Instruction::ISZERO;
break;
case Token::GreaterThan:
m_context << (isSigned ? eth::Instruction::SGT : eth::Instruction::GT);
break;
case Token::LessThan:
m_context << (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;
case Token::Exp:
m_context << eth::Instruction::EXP;
break;
default:
BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown arithmetic operator."));
}
}
void ExpressionCompiler::appendBitOperatorCode(Token::Value _operator)
{
switch (_operator)
{
case Token::BitOr:
m_context << eth::Instruction::OR;
break;
case Token::BitAnd:
m_context << eth::Instruction::AND;
break;
case Token::BitXor:
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::appendExternalFunctionCall(
FunctionType const& _functionType,
vector<ASTPointer<Expression const>> const& _arguments
)
{
solAssert(
_functionType.takesArbitraryParameters() ||
_arguments.size() == _functionType.parameterTypes().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 + (_functionType.isBareCall() ? 0 : 1));
unsigned gasStackPos = m_context.currentToBaseStackOffset(gasValueSize);
unsigned valueStackPos = m_context.currentToBaseStackOffset(1);
using FunctionKind = FunctionType::Location;
FunctionKind funKind = _functionType.location();
bool returnSuccessCondition = funKind == FunctionKind::Bare || funKind == FunctionKind::BareCallCode;
bool isCallCode = funKind == FunctionKind::BareCallCode || funKind == FunctionKind::CallCode;
//@todo only return the first return value for now
Type const* firstReturnType =
_functionType.returnParameterTypes().empty() ?
nullptr :
_functionType.returnParameterTypes().front().get();
unsigned retSize = 0;
if (returnSuccessCondition)
retSize = 0; // return value actually is success condition
else if (firstReturnType)
{
retSize = firstReturnType->calldataEncodedSize();
solAssert(retSize > 0, "Unable to return dynamic type from external call.");
}
// Evaluate arguments.
TypePointers argumentTypes;
bool manualFunctionId =
(funKind == FunctionKind::Bare || funKind == FunctionKind::BareCallCode) &&
!_arguments.empty() &&
_arguments.front()->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
// function identifier.
_arguments.front()->accept(*this);
utils().convertType(
*_arguments.front()->type(),
IntegerType(8 * CompilerUtils::dataStartOffset),
true
);
for (unsigned i = 0; i < gasValueSize; ++i)
m_context << eth::swapInstruction(gasValueSize - i);
gasStackPos++;
valueStackPos++;
}
for (size_t i = manualFunctionId ? 1 : 0; i < _arguments.size(); ++i)
{
_arguments[i]->accept(*this);
argumentTypes.push_back(_arguments[i]->type());
}
// Copy function identifier to memory.
utils().fetchFreeMemoryPointer();
if (!_functionType.isBareCall() || manualFunctionId)
{
m_context << eth::dupInstruction(2 + gasValueSize + CompilerUtils::sizeOnStack(argumentTypes));
utils().storeInMemoryDynamic(IntegerType(8 * CompilerUtils::dataStartOffset), false);
}
// If the function takes arbitrary parameters, copy dynamic length data in place.
// Move argumenst to memory, will not update the free memory pointer (but will update the memory
// pointer on the stack).
utils().encodeToMemory(
argumentTypes,
_functionType.parameterTypes(),
_functionType.padArguments(),
_functionType.takesArbitraryParameters()
);
// Stack now:
// <stack top>
// input_memory_end
// value [if _functionType.valueSet()]
// gas [if _functionType.gasSet()]
// function identifier [unless bare]
// contract address
// Output data will replace input data.
// put on stack: <size of output> <memory pos of output> <size of input> <memory pos of input>
m_context << u256(retSize);
utils().fetchFreeMemoryPointer();
m_context << eth::Instruction::DUP1 << eth::Instruction::DUP4 << eth::Instruction::SUB;
m_context << eth::Instruction::DUP2;
// CALL arguments: outSize, outOff, inSize, inOff (already present up to here)
// value, addr, gas (stack top)
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 the amount needed to execute "SUB" and "CALL"
// @todo this retains too much gas for now, needs to be fine-tuned.
u256 gasNeededByCaller = eth::c_callGas + 10;
if (_functionType.valueSet())
gasNeededByCaller += eth::c_callValueTransferGas;
if (!isCallCode)
gasNeededByCaller += eth::c_callNewAccountGas; // we never know
m_context <<
gasNeededByCaller <<
eth::Instruction::GAS <<
eth::Instruction::SUB;
}
if (isCallCode)
m_context << eth::Instruction::CALLCODE;
else
m_context << eth::Instruction::CALL;
unsigned remainsSize =
2 + // contract address, input_memory_end
_functionType.valueSet() +
_functionType.gasSet() +
(!_functionType.isBareCall() || manualFunctionId);
if (returnSuccessCondition)
m_context << eth::swapInstruction(remainsSize);
else
{
//Propagate error condition (if CALL pushes 0 on stack).
m_context << eth::Instruction::ISZERO;
m_context.appendConditionalJumpTo(m_context.errorTag());
}
utils().popStackSlots(remainsSize);
if (returnSuccessCondition)
{
// already there
}
else if (funKind == FunctionKind::RIPEMD160)
{
// fix: built-in contract returns right-aligned data
utils().fetchFreeMemoryPointer();
utils().loadFromMemoryDynamic(IntegerType(160), false, true, false);
utils().convertType(IntegerType(160), FixedBytesType(20));
}
else if (firstReturnType)
{
//@todo manually update free memory pointer if we accept returning memory-stored objects
utils().fetchFreeMemoryPointer();
utils().loadFromMemoryDynamic(*firstReturnType, false, true, false);
}
}
void ExpressionCompiler::appendExpressionCopyToMemory(Type const& _expectedType, Expression const& _expression)
{
solAssert(_expectedType.isValueType(), "Not implemented for non-value types.");
_expression.accept(*this);
utils().convertType(*_expression.type(), _expectedType, true);
utils().storeInMemoryDynamic(_expectedType);
}
void ExpressionCompiler::setLValueFromDeclaration(Declaration const& _declaration, Expression const& _expression)
{
if (m_context.isLocalVariable(&_declaration))
setLValue<StackVariable>(_expression, _declaration);
else if (m_context.isStateVariable(&_declaration))
setLValue<StorageItem>(_expression, _declaration);
else
BOOST_THROW_EXCEPTION(InternalCompilerError()
<< errinfo_sourceLocation(_expression.location())
<< errinfo_comment("Identifier type not supported or identifier not found."));
}
void ExpressionCompiler::setLValueToStorageItem(Expression const& _expression)
{
setLValue<StorageItem>(_expression, *_expression.type());
}
CompilerUtils ExpressionCompiler::utils()
{
return CompilerUtils(m_context);
}
}
}