/*
This file is part of solidity.
solidity 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.
solidity 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 solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2014
* Solidity compiler.
*/
#include <libsolidity/codegen/ContractCompiler.h>
#include <algorithm>
#include <boost/range/adaptor/reversed.hpp>
#include <libevmasm/Instruction.h>
#include <libevmasm/Assembly.h>
#include <libevmasm/GasMeter.h>
#include <libsolidity/inlineasm/AsmCodeGen.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/codegen/ExpressionCompiler.h>
#include <libsolidity/codegen/CompilerUtils.h>
using namespace std;
using namespace dev;
using namespace dev::solidity;
/**
* Simple helper class to ensure that the stack height is the same at certain places in the code.
*/
class StackHeightChecker
{
public:
StackHeightChecker(CompilerContext const& _context):
m_context(_context), stackHeight(m_context.stackHeight()) {}
void check() { solAssert(m_context.stackHeight() == stackHeight, std::string("I sense a disturbance in the stack: ") + std::to_string(m_context.stackHeight()) + " vs " + std::to_string(stackHeight)); }
private:
CompilerContext const& m_context;
unsigned stackHeight;
};
void ContractCompiler::compileContract(
ContractDefinition const& _contract,
std::map<const ContractDefinition*, eth::Assembly const*> const& _contracts
)
{
CompilerContext::LocationSetter locationSetter(m_context, _contract);
initializeContext(_contract, _contracts);
appendFunctionSelector(_contract);
appendMissingFunctions();
}
size_t ContractCompiler::compileConstructor(
ContractDefinition const& _contract,
std::map<const ContractDefinition*, eth::Assembly const*> const& _contracts
)
{
CompilerContext::LocationSetter locationSetter(m_context, _contract);
initializeContext(_contract, _contracts);
return packIntoContractCreator(_contract);
}
size_t ContractCompiler::compileClone(
ContractDefinition const& _contract,
map<ContractDefinition const*, eth::Assembly const*> const& _contracts
)
{
initializeContext(_contract, _contracts);
appendInitAndConstructorCode(_contract);
//@todo determine largest return size of all runtime functions
auto runtimeSub = m_context.addSubroutine(cloneRuntime());
// stack contains sub size
m_context << Instruction::DUP1 << runtimeSub << u256(0) << Instruction::CODECOPY;
m_context << u256(0) << Instruction::RETURN;
appendMissingFunctions();
return size_t(runtimeSub.data());
}
void ContractCompiler::initializeContext(
ContractDefinition const& _contract,
map<ContractDefinition const*, eth::Assembly const*> const& _compiledContracts
)
{
m_context.setCompiledContracts(_compiledContracts);
m_context.setInheritanceHierarchy(_contract.annotation().linearizedBaseContracts);
CompilerUtils(m_context).initialiseFreeMemoryPointer();
registerStateVariables(_contract);
m_context.resetVisitedNodes(&_contract);
}
void ContractCompiler::appendCallValueCheck()
{
// Throw if function is not payable but call contained ether.
m_context << Instruction::CALLVALUE;
m_context.appendConditionalInvalid();
}
void ContractCompiler::appendInitAndConstructorCode(ContractDefinition const& _contract)
{
// Determine the arguments that are used for the base constructors.
std::vector<ContractDefinition const*> const& bases = _contract.annotation().linearizedBaseContracts;
for (ContractDefinition const* contract: bases)
{
if (FunctionDefinition const* constructor = contract->constructor())
for (auto const& modifier: constructor->modifiers())
{
auto baseContract = dynamic_cast<ContractDefinition const*>(
modifier->name()->annotation().referencedDeclaration);
if (baseContract)
if (m_baseArguments.count(baseContract->constructor()) == 0)
m_baseArguments[baseContract->constructor()] = &modifier->arguments();
}
for (ASTPointer<InheritanceSpecifier> const& base: contract->baseContracts())
{
ContractDefinition const* baseContract = dynamic_cast<ContractDefinition const*>(
base->name().annotation().referencedDeclaration
);
solAssert(baseContract, "");
if (m_baseArguments.count(baseContract->constructor()) == 0)
m_baseArguments[baseContract->constructor()] = &base->arguments();
}
}
// Initialization of state variables in base-to-derived order.
for (ContractDefinition const* contract: boost::adaptors::reverse(bases))
initializeStateVariables(*contract);
if (FunctionDefinition const* constructor = _contract.constructor())
appendConstructor(*constructor);
else if (auto c = m_context.nextConstructor(_contract))
appendBaseConstructor(*c);
else
appendCallValueCheck();
}
size_t ContractCompiler::packIntoContractCreator(ContractDefinition const& _contract)
{
solAssert(!!m_runtimeCompiler, "");
appendInitAndConstructorCode(_contract);
// We jump to the deploy routine because we first have to append all missing functions,
// which can cause further functions to be added to the runtime context.
eth::AssemblyItem deployRoutine = m_context.appendJumpToNew();
// We have to include copies of functions in the construction time and runtime context
// because of absolute jumps.
appendMissingFunctions();
m_runtimeCompiler->appendMissingFunctions();
m_context << deployRoutine;
solAssert(m_context.runtimeSub() != size_t(-1), "Runtime sub not registered");
m_context.pushSubroutineSize(m_context.runtimeSub());
m_context << Instruction::DUP1;
m_context.pushSubroutineOffset(m_context.runtimeSub());
m_context << u256(0) << Instruction::CODECOPY;
m_context << u256(0) << Instruction::RETURN;
return m_context.runtimeSub();
}
void ContractCompiler::appendBaseConstructor(FunctionDefinition const& _constructor)
{
CompilerContext::LocationSetter locationSetter(m_context, _constructor);
FunctionType constructorType(_constructor);
if (!constructorType.parameterTypes().empty())
{
solAssert(m_baseArguments.count(&_constructor), "");
std::vector<ASTPointer<Expression>> const* arguments = m_baseArguments[&_constructor];
solAssert(arguments, "");
for (unsigned i = 0; i < arguments->size(); ++i)
compileExpression(*(arguments->at(i)), constructorType.parameterTypes()[i]);
}
_constructor.accept(*this);
}
void ContractCompiler::appendConstructor(FunctionDefinition const& _constructor)
{
CompilerContext::LocationSetter locationSetter(m_context, _constructor);
if (!_constructor.isPayable())
appendCallValueCheck();
// copy constructor arguments from code to memory and then to stack, they are supplied after the actual program
if (!_constructor.parameters().empty())
{
unsigned argumentSize = 0;
for (ASTPointer<VariableDeclaration> const& var: _constructor.parameters())
if (var->annotation().type->isDynamicallySized())
{
argumentSize = 0;
break;
}
else
argumentSize += var->annotation().type->calldataEncodedSize();
CompilerUtils(m_context).fetchFreeMemoryPointer();
if (argumentSize == 0)
{
// argument size is dynamic, use CODESIZE to determine it
m_context.appendProgramSize(); // program itself
// CODESIZE is program plus manually added arguments
m_context << Instruction::CODESIZE << Instruction::SUB;
}
else
m_context << u256(argumentSize);
// stack: <memptr> <argument size>
m_context << Instruction::DUP1;
m_context.appendProgramSize();
m_context << Instruction::DUP4 << Instruction::CODECOPY;
m_context << Instruction::DUP2 << Instruction::ADD;
CompilerUtils(m_context).storeFreeMemoryPointer();
// stack: <memptr>
appendCalldataUnpacker(FunctionType(_constructor).parameterTypes(), true);
}
_constructor.accept(*this);
}
void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contract)
{
map<FixedHash<4>, FunctionTypePointer> interfaceFunctions = _contract.interfaceFunctions();
map<FixedHash<4>, const eth::AssemblyItem> callDataUnpackerEntryPoints;
FunctionDefinition const* fallback = _contract.fallbackFunction();
eth::AssemblyItem notFound = m_context.newTag();
// shortcut messages without data if we have many functions in order to be able to receive
// ether with constant gas
if (interfaceFunctions.size() > 5 || fallback)
{
m_context << Instruction::CALLDATASIZE << Instruction::ISZERO;
m_context.appendConditionalJumpTo(notFound);
}
// retrieve the function signature hash from the calldata
if (!interfaceFunctions.empty())
CompilerUtils(m_context).loadFromMemory(0, IntegerType(CompilerUtils::dataStartOffset * 8), true);
// stack now is: 1 0 <funhash>
for (auto const& it: interfaceFunctions)
{
callDataUnpackerEntryPoints.insert(std::make_pair(it.first, m_context.newTag()));
m_context << dupInstruction(1) << u256(FixedHash<4>::Arith(it.first)) << Instruction::EQ;
m_context.appendConditionalJumpTo(callDataUnpackerEntryPoints.at(it.first));
}
m_context.appendJumpTo(notFound);
m_context << notFound;
if (fallback)
{
if (!fallback->isPayable())
appendCallValueCheck();
eth::AssemblyItem returnTag = m_context.pushNewTag();
fallback->accept(*this);
m_context << returnTag;
appendReturnValuePacker(FunctionType(*fallback).returnParameterTypes(), _contract.isLibrary());
}
else
m_context.appendInvalid();
for (auto const& it: interfaceFunctions)
{
FunctionTypePointer const& functionType = it.second;
solAssert(functionType->hasDeclaration(), "");
CompilerContext::LocationSetter locationSetter(m_context, functionType->declaration());
m_context << callDataUnpackerEntryPoints.at(it.first);
// We have to allow this for libraries, because value of the previous
// call is still visible in the delegatecall.
if (!functionType->isPayable() && !_contract.isLibrary())
appendCallValueCheck();
eth::AssemblyItem returnTag = m_context.pushNewTag();
m_context << CompilerUtils::dataStartOffset;
appendCalldataUnpacker(functionType->parameterTypes());
m_context.appendJumpTo(m_context.functionEntryLabel(functionType->declaration()));
m_context << returnTag;
appendReturnValuePacker(functionType->returnParameterTypes(), _contract.isLibrary());
}
}
void ContractCompiler::appendCalldataUnpacker(TypePointers const& _typeParameters, bool _fromMemory)
{
// We do not check the calldata size, everything is zero-padded
//@todo this does not yet support nested dynamic arrays
// Retain the offset pointer as base_offset, the point from which the data offsets are computed.
m_context << Instruction::DUP1;
for (TypePointer const& parameterType: _typeParameters)
{
// stack: v1 v2 ... v(k-1) base_offset current_offset
TypePointer type = parameterType->decodingType();
solAssert(type, "No decoding type found.");
if (type->category() == Type::Category::Array)
{
auto const& arrayType = dynamic_cast<ArrayType const&>(*type);
solUnimplementedAssert(!arrayType.baseType()->isDynamicallySized(), "Nested arrays not yet implemented.");
if (_fromMemory)
{
solUnimplementedAssert(
arrayType.baseType()->isValueType(),
"Nested memory arrays not yet implemented here."
);
// @todo If base type is an array or struct, it is still calldata-style encoded, so
// we would have to convert it like below.
solAssert(arrayType.location() == DataLocation::Memory, "");
if (arrayType.isDynamicallySized())
{
// compute data pointer
m_context << Instruction::DUP1 << Instruction::MLOAD;
m_context << Instruction::DUP3 << Instruction::ADD;
m_context << Instruction::SWAP2 << Instruction::SWAP1;
m_context << u256(0x20) << Instruction::ADD;
}
else
{
m_context << Instruction::SWAP1 << Instruction::DUP2;
m_context << u256(arrayType.calldataEncodedSize(true)) << Instruction::ADD;
}
}
else
{
// first load from calldata and potentially convert to memory if arrayType is memory
TypePointer calldataType = arrayType.copyForLocation(DataLocation::CallData, false);
if (calldataType->isDynamicallySized())
{
// put on stack: data_pointer length
CompilerUtils(m_context).loadFromMemoryDynamic(IntegerType(256), !_fromMemory);
// stack: base_offset data_offset next_pointer
m_context << Instruction::SWAP1 << Instruction::DUP3 << Instruction::ADD;
// stack: base_offset next_pointer data_pointer
// retrieve length
CompilerUtils(m_context).loadFromMemoryDynamic(IntegerType(256), !_fromMemory, true);
// stack: base_offset next_pointer length data_pointer
m_context << Instruction::SWAP2;
// stack: base_offset data_pointer length next_pointer
}
else
{
// leave the pointer on the stack
m_context << Instruction::DUP1;
m_context << u256(calldataType->calldataEncodedSize()) << Instruction::ADD;
}
if (arrayType.location() == DataLocation::Memory)
{
// stack: base_offset calldata_ref [length] next_calldata
// copy to memory
// move calldata type up again
CompilerUtils(m_context).moveIntoStack(calldataType->sizeOnStack());
CompilerUtils(m_context).convertType(*calldataType, arrayType);
// fetch next pointer again
CompilerUtils(m_context).moveToStackTop(arrayType.sizeOnStack());
}
// move base_offset up
CompilerUtils(m_context).moveToStackTop(1 + arrayType.sizeOnStack());
m_context << Instruction::SWAP1;
}
}
else
{
solAssert(!type->isDynamicallySized(), "Unknown dynamically sized type: " + type->toString());
CompilerUtils(m_context).loadFromMemoryDynamic(*type, !_fromMemory, true);
CompilerUtils(m_context).moveToStackTop(1 + type->sizeOnStack());
m_context << Instruction::SWAP1;
}
// stack: v1 v2 ... v(k-1) v(k) base_offset mem_offset
}
m_context << Instruction::POP << Instruction::POP;
}
void ContractCompiler::appendReturnValuePacker(TypePointers const& _typeParameters, bool _isLibrary)
{
CompilerUtils utils(m_context);
if (_typeParameters.empty())
m_context << Instruction::STOP;
else
{
utils.fetchFreeMemoryPointer();
//@todo optimization: if we return a single memory array, there should be enough space before
// its data to add the needed parts and we avoid a memory copy.
utils.encodeToMemory(_typeParameters, _typeParameters, true, false, _isLibrary);
utils.toSizeAfterFreeMemoryPointer();
m_context << Instruction::RETURN;
}
}
void ContractCompiler::registerStateVariables(ContractDefinition const& _contract)
{
for (auto const& var: ContractType(_contract).stateVariables())
m_context.addStateVariable(*get<0>(var), get<1>(var), get<2>(var));
}
void ContractCompiler::initializeStateVariables(ContractDefinition const& _contract)
{
for (VariableDeclaration const* variable: _contract.stateVariables())
if (variable->value() && !variable->isConstant())
ExpressionCompiler(m_context, m_optimise).appendStateVariableInitialization(*variable);
}
bool ContractCompiler::visit(VariableDeclaration const& _variableDeclaration)
{
solAssert(_variableDeclaration.isStateVariable(), "Compiler visit to non-state variable declaration.");
CompilerContext::LocationSetter locationSetter(m_context, _variableDeclaration);
m_context.startFunction(_variableDeclaration);
m_breakTags.clear();
m_continueTags.clear();
if (_variableDeclaration.isConstant())
ExpressionCompiler(m_context, m_optimise).appendConstStateVariableAccessor(_variableDeclaration);
else
ExpressionCompiler(m_context, m_optimise).appendStateVariableAccessor(_variableDeclaration);
return false;
}
bool ContractCompiler::visit(FunctionDefinition const& _function)
{
CompilerContext::LocationSetter locationSetter(m_context, _function);
m_context.startFunction(_function);
// stack upon entry: [return address] [arg0] [arg1] ... [argn]
// reserve additional slots: [retarg0] ... [retargm] [localvar0] ... [localvarp]
unsigned parametersSize = CompilerUtils::sizeOnStack(_function.parameters());
if (!_function.isConstructor())
// adding 1 for return address.
m_context.adjustStackOffset(parametersSize + 1);
for (ASTPointer<VariableDeclaration const> const& variable: _function.parameters())
{
m_context.addVariable(*variable, parametersSize);
parametersSize -= variable->annotation().type->sizeOnStack();
}
for (ASTPointer<VariableDeclaration const> const& variable: _function.returnParameters())
appendStackVariableInitialisation(*variable);
for (VariableDeclaration const* localVariable: _function.localVariables())
appendStackVariableInitialisation(*localVariable);
if (_function.isConstructor())
if (auto c = m_context.nextConstructor(dynamic_cast<ContractDefinition const&>(*_function.scope())))
appendBaseConstructor(*c);
solAssert(m_returnTags.empty(), "");
m_breakTags.clear();
m_continueTags.clear();
m_stackCleanupForReturn = 0;
m_currentFunction = &_function;
m_modifierDepth = -1;
appendModifierOrFunctionCode();
solAssert(m_returnTags.empty(), "");
// Now we need to re-shuffle the stack. For this we keep a record of the stack layout
// that shows the target positions of the elements, where "-1" denotes that this element needs
// to be removed from the stack.
// Note that the fact that the return arguments are of increasing index is vital for this
// algorithm to work.
unsigned const c_argumentsSize = CompilerUtils::sizeOnStack(_function.parameters());
unsigned const c_returnValuesSize = CompilerUtils::sizeOnStack(_function.returnParameters());
unsigned const c_localVariablesSize = CompilerUtils::sizeOnStack(_function.localVariables());
vector<int> stackLayout;
stackLayout.push_back(c_returnValuesSize); // target of return address
stackLayout += vector<int>(c_argumentsSize, -1); // discard all arguments
for (unsigned i = 0; i < c_returnValuesSize; ++i)
stackLayout.push_back(i);
stackLayout += vector<int>(c_localVariablesSize, -1);
if (stackLayout.size() > 17)
BOOST_THROW_EXCEPTION(
CompilerError() <<
errinfo_sourceLocation(_function.location()) <<
errinfo_comment("Stack too deep, try removing local variables.")
);
while (stackLayout.back() != int(stackLayout.size() - 1))
if (stackLayout.back() < 0)
{
m_context << Instruction::POP;
stackLayout.pop_back();
}
else
{
m_context << swapInstruction(stackLayout.size() - stackLayout.back() - 1);
swap(stackLayout[stackLayout.back()], stackLayout.back());
}
//@todo assert that everything is in place now
for (ASTPointer<VariableDeclaration const> const& variable: _function.parameters() + _function.returnParameters())
m_context.removeVariable(*variable);
for (VariableDeclaration const* localVariable: _function.localVariables())
m_context.removeVariable(*localVariable);
m_context.adjustStackOffset(-(int)c_returnValuesSize);
if (!_function.isConstructor())
m_context.appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
return false;
}
bool ContractCompiler::visit(InlineAssembly const& _inlineAssembly)
{
ErrorList errors;
assembly::CodeGenerator codeGen(errors);
unsigned startStackHeight = m_context.stackHeight();
assembly::ExternalIdentifierAccess identifierAccess;
identifierAccess.resolve = [&](assembly::Identifier const& _identifier, assembly::IdentifierContext)
{
auto ref = _inlineAssembly.annotation().externalReferences.find(&_identifier);
if (ref == _inlineAssembly.annotation().externalReferences.end())
return size_t(-1);
return ref->second.valueSize;
};
identifierAccess.generateCode = [&](assembly::Identifier const& _identifier, assembly::IdentifierContext _context, julia::AbstractAssembly& _assembly)
{
auto ref = _inlineAssembly.annotation().externalReferences.find(&_identifier);
solAssert(ref != _inlineAssembly.annotation().externalReferences.end(), "");
Declaration const* decl = ref->second.declaration;
solAssert(!!decl, "");
if (_context == assembly::IdentifierContext::RValue)
{
int const depositBefore = _assembly.stackHeight();
solAssert(!!decl->type(), "Type of declaration required but not yet determined.");
if (FunctionDefinition const* functionDef = dynamic_cast<FunctionDefinition const*>(decl))
{
solAssert(!ref->second.isOffset && !ref->second.isSlot, "");
functionDef = &m_context.resolveVirtualFunction(*functionDef);
auto functionEntryLabel = m_context.functionEntryLabel(*functionDef).pushTag();
solAssert(functionEntryLabel.data() <= std::numeric_limits<size_t>::max(), "");
_assembly.appendLabelReference(size_t(functionEntryLabel.data()));
// If there is a runtime context, we have to merge both labels into the same
// stack slot in case we store it in storage.
if (CompilerContext* rtc = m_context.runtimeContext())
{
_assembly.appendConstant(u256(1) << 32);
_assembly.appendInstruction(Instruction::MUL);
auto runtimeEntryLabel = rtc->functionEntryLabel(*functionDef).toSubAssemblyTag(m_context.runtimeSub());
solAssert(runtimeEntryLabel.data() <= std::numeric_limits<size_t>::max(), "");
_assembly.appendLabelReference(size_t(runtimeEntryLabel.data()));
_assembly.appendInstruction(Instruction::OR);
}
}
else if (auto variable = dynamic_cast<VariableDeclaration const*>(decl))
{
solAssert(!variable->isConstant(), "");
if (m_context.isStateVariable(decl))
{
auto const& location = m_context.storageLocationOfVariable(*decl);
if (ref->second.isSlot)
m_context << location.first;
else if (ref->second.isOffset)
m_context << u256(location.second);
else
solAssert(false, "");
}
else if (m_context.isLocalVariable(decl))
{
int stackDiff = _assembly.stackHeight() - m_context.baseStackOffsetOfVariable(*variable);
if (ref->second.isSlot || ref->second.isOffset)
{
solAssert(variable->type()->dataStoredIn(DataLocation::Storage), "");
unsigned size = variable->type()->sizeOnStack();
if (size == 2)
{
// slot plus offset
if (ref->second.isOffset)
stackDiff--;
}
else
{
solAssert(size == 1, "");
// only slot, offset is zero
if (ref->second.isOffset)
{
_assembly.appendConstant(u256(0));
return;
}
}
}
else
solAssert(variable->type()->sizeOnStack() == 1, "");
if (stackDiff < 1 || stackDiff > 16)
BOOST_THROW_EXCEPTION(
CompilerError() <<
errinfo_sourceLocation(_inlineAssembly.location()) <<
errinfo_comment("Stack too deep, try removing local variables.")
);
solAssert(variable->type()->sizeOnStack() == 1, "");
_assembly.appendInstruction(dupInstruction(stackDiff));
}
else
solAssert(false, "");
}
else if (auto contract = dynamic_cast<ContractDefinition const*>(decl))
{
solAssert(!ref->second.isOffset && !ref->second.isSlot, "");
solAssert(contract->isLibrary(), "");
_assembly.appendLinkerSymbol(contract->fullyQualifiedName());
}
else
solAssert(false, "Invalid declaration type.");
solAssert(_assembly.stackHeight() - depositBefore == int(ref->second.valueSize), "");
}
else
{
// lvalue context
solAssert(!ref->second.isOffset && !ref->second.isSlot, "");
auto variable = dynamic_cast<VariableDeclaration const*>(decl);
solAssert(
!!variable && m_context.isLocalVariable(variable),
"Can only assign to stack variables in inline assembly."
);
solAssert(variable->type()->sizeOnStack() == 1, "");
int stackDiff = _assembly.stackHeight() - m_context.baseStackOffsetOfVariable(*variable) - 1;
if (stackDiff > 16 || stackDiff < 1)
BOOST_THROW_EXCEPTION(
CompilerError() <<
errinfo_sourceLocation(_inlineAssembly.location()) <<
errinfo_comment("Stack too deep(" + to_string(stackDiff) + "), try removing local variables.")
);
_assembly.appendInstruction(swapInstruction(stackDiff));
_assembly.appendInstruction(Instruction::POP);
}
};
solAssert(_inlineAssembly.annotation().analysisInfo, "");
codeGen.assemble(
_inlineAssembly.operations(),
*_inlineAssembly.annotation().analysisInfo,
m_context.nonConstAssembly(),
identifierAccess
);
solAssert(Error::containsOnlyWarnings(errors), "Code generation for inline assembly with errors requested.");
m_context.setStackOffset(startStackHeight);
return false;
}
bool ContractCompiler::visit(IfStatement const& _ifStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _ifStatement);
compileExpression(_ifStatement.condition());
m_context << Instruction::ISZERO;
eth::AssemblyItem falseTag = m_context.appendConditionalJump();
eth::AssemblyItem endTag = falseTag;
_ifStatement.trueStatement().accept(*this);
if (_ifStatement.falseStatement())
{
endTag = m_context.appendJumpToNew();
m_context << falseTag;
_ifStatement.falseStatement()->accept(*this);
}
m_context << endTag;
checker.check();
return false;
}
bool ContractCompiler::visit(WhileStatement const& _whileStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _whileStatement);
eth::AssemblyItem loopStart = m_context.newTag();
eth::AssemblyItem loopEnd = m_context.newTag();
m_continueTags.push_back(loopStart);
m_breakTags.push_back(loopEnd);
m_context << loopStart;
// While loops have the condition prepended
if (!_whileStatement.isDoWhile())
{
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
}
_whileStatement.body().accept(*this);
// Do-while loops have the condition appended
if (_whileStatement.isDoWhile())
{
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
}
m_context.appendJumpTo(loopStart);
m_context << loopEnd;
m_continueTags.pop_back();
m_breakTags.pop_back();
checker.check();
return false;
}
bool ContractCompiler::visit(ForStatement const& _forStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _forStatement);
eth::AssemblyItem loopStart = m_context.newTag();
eth::AssemblyItem loopEnd = m_context.newTag();
eth::AssemblyItem loopNext = m_context.newTag();
m_continueTags.push_back(loopNext);
m_breakTags.push_back(loopEnd);
if (_forStatement.initializationExpression())
_forStatement.initializationExpression()->accept(*this);
m_context << loopStart;
// if there is no terminating condition in for, default is to always be true
if (_forStatement.condition())
{
compileExpression(*_forStatement.condition());
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
}
_forStatement.body().accept(*this);
m_context << loopNext;
// for's loop expression if existing
if (_forStatement.loopExpression())
_forStatement.loopExpression()->accept(*this);
m_context.appendJumpTo(loopStart);
m_context << loopEnd;
m_continueTags.pop_back();
m_breakTags.pop_back();
checker.check();
return false;
}
bool ContractCompiler::visit(Continue const& _continueStatement)
{
CompilerContext::LocationSetter locationSetter(m_context, _continueStatement);
if (!m_continueTags.empty())
m_context.appendJumpTo(m_continueTags.back());
return false;
}
bool ContractCompiler::visit(Break const& _breakStatement)
{
CompilerContext::LocationSetter locationSetter(m_context, _breakStatement);
if (!m_breakTags.empty())
m_context.appendJumpTo(m_breakTags.back());
return false;
}
bool ContractCompiler::visit(Return const& _return)
{
CompilerContext::LocationSetter locationSetter(m_context, _return);
if (Expression const* expression = _return.expression())
{
solAssert(_return.annotation().functionReturnParameters, "Invalid return parameters pointer.");
vector<ASTPointer<VariableDeclaration>> const& returnParameters =
_return.annotation().functionReturnParameters->parameters();
TypePointers types;
for (auto const& retVariable: returnParameters)
types.push_back(retVariable->annotation().type);
TypePointer expectedType;
if (expression->annotation().type->category() == Type::Category::Tuple || types.size() != 1)
expectedType = make_shared<TupleType>(types);
else
expectedType = types.front();
compileExpression(*expression, expectedType);
for (auto const& retVariable: boost::adaptors::reverse(returnParameters))
CompilerUtils(m_context).moveToStackVariable(*retVariable);
}
for (unsigned i = 0; i < m_stackCleanupForReturn; ++i)
m_context << Instruction::POP;
m_context.appendJumpTo(m_returnTags.back());
m_context.adjustStackOffset(m_stackCleanupForReturn);
return false;
}
bool ContractCompiler::visit(Throw const& _throw)
{
CompilerContext::LocationSetter locationSetter(m_context, _throw);
// Do not send back an error detail.
m_context << u256(0) << u256(0);
m_context << Instruction::REVERT;
return false;
}
bool ContractCompiler::visit(VariableDeclarationStatement const& _variableDeclarationStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _variableDeclarationStatement);
if (Expression const* expression = _variableDeclarationStatement.initialValue())
{
CompilerUtils utils(m_context);
compileExpression(*expression);
TypePointers valueTypes;
if (auto tupleType = dynamic_cast<TupleType const*>(expression->annotation().type.get()))
valueTypes = tupleType->components();
else
valueTypes = TypePointers{expression->annotation().type};
auto const& assignments = _variableDeclarationStatement.annotation().assignments;
solAssert(assignments.size() == valueTypes.size(), "");
for (size_t i = 0; i < assignments.size(); ++i)
{
size_t j = assignments.size() - i - 1;
solAssert(!!valueTypes[j], "");
VariableDeclaration const* varDecl = assignments[j];
if (!varDecl)
utils.popStackElement(*valueTypes[j]);
else
{
utils.convertType(*valueTypes[j], *varDecl->annotation().type);
utils.moveToStackVariable(*varDecl);
}
}
}
checker.check();
return false;
}
bool ContractCompiler::visit(ExpressionStatement const& _expressionStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _expressionStatement);
Expression const& expression = _expressionStatement.expression();
compileExpression(expression);
CompilerUtils(m_context).popStackElement(*expression.annotation().type);
checker.check();
return false;
}
bool ContractCompiler::visit(PlaceholderStatement const& _placeholderStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _placeholderStatement);
appendModifierOrFunctionCode();
checker.check();
return true;
}
void ContractCompiler::appendMissingFunctions()
{
while (Declaration const* function = m_context.nextFunctionToCompile())
{
m_context.setStackOffset(0);
function->accept(*this);
solAssert(m_context.nextFunctionToCompile() != function, "Compiled the wrong function?");
}
m_context.appendMissingLowLevelFunctions();
}
void ContractCompiler::appendModifierOrFunctionCode()
{
solAssert(m_currentFunction, "");
unsigned stackSurplus = 0;
Block const* codeBlock = nullptr;
m_modifierDepth++;
if (m_modifierDepth >= m_currentFunction->modifiers().size())
{
solAssert(m_currentFunction->isImplemented(), "");
codeBlock = &m_currentFunction->body();
}
else
{
ASTPointer<ModifierInvocation> const& modifierInvocation = m_currentFunction->modifiers()[m_modifierDepth];
// constructor call should be excluded
if (dynamic_cast<ContractDefinition const*>(modifierInvocation->name()->annotation().referencedDeclaration))
appendModifierOrFunctionCode();
else
{
ModifierDefinition const& modifier = m_context.functionModifier(modifierInvocation->name()->name());
CompilerContext::LocationSetter locationSetter(m_context, modifier);
solAssert(modifier.parameters().size() == modifierInvocation->arguments().size(), "");
for (unsigned i = 0; i < modifier.parameters().size(); ++i)
{
m_context.addVariable(*modifier.parameters()[i]);
compileExpression(
*modifierInvocation->arguments()[i],
modifier.parameters()[i]->annotation().type
);
}
for (VariableDeclaration const* localVariable: modifier.localVariables())
appendStackVariableInitialisation(*localVariable);
stackSurplus =
CompilerUtils::sizeOnStack(modifier.parameters()) +
CompilerUtils::sizeOnStack(modifier.localVariables());
codeBlock = &modifier.body();
}
}
if (codeBlock)
{
m_returnTags.push_back(m_context.newTag());
codeBlock->accept(*this);
solAssert(!m_returnTags.empty(), "");
m_context << m_returnTags.back();
m_returnTags.pop_back();
CompilerUtils(m_context).popStackSlots(stackSurplus);
}
m_modifierDepth--;
}
void ContractCompiler::appendStackVariableInitialisation(VariableDeclaration const& _variable)
{
CompilerContext::LocationSetter location(m_context, _variable);
m_context.addVariable(_variable);
CompilerUtils(m_context).pushZeroValue(*_variable.annotation().type);
}
void ContractCompiler::compileExpression(Expression const& _expression, TypePointer const& _targetType)
{
ExpressionCompiler expressionCompiler(m_context, m_optimise);
expressionCompiler.compile(_expression);
if (_targetType)
CompilerUtils(m_context).convertType(*_expression.annotation().type, *_targetType);
}
eth::AssemblyPointer ContractCompiler::cloneRuntime()
{
eth::Assembly a;
a << Instruction::CALLDATASIZE;
a << u256(0) << Instruction::DUP1 << Instruction::CALLDATACOPY;
//@todo adjust for larger return values, make this dynamic.
a << u256(0x20) << u256(0) << Instruction::CALLDATASIZE;
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(eth::GasCosts::callGas + 10) << Instruction::GAS << Instruction::SUB;
a << Instruction::DELEGATECALL;
//Propagate error condition (if DELEGATECALL pushes 0 on stack).
a << Instruction::ISZERO;
a << Instruction::ISZERO;
eth::AssemblyItem afterTag = a.appendJumpI().tag();
a << Instruction::INVALID << afterTag;
//@todo adjust for larger return values, make this dynamic.
a << u256(0x20) << u256(0) << Instruction::RETURN;
return make_shared<eth::Assembly>(a);
}
