solidity/libsolidity/codegen/ContractCompiler.cpp

1075 lines
37 KiB
C++

/*
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/ast/AST.h>
#include <libsolidity/ast/TypeProvider.h>
#include <libsolidity/codegen/CompilerUtils.h>
#include <libsolidity/codegen/ContractCompiler.h>
#include <libsolidity/codegen/ExpressionCompiler.h>
#include <libyul/backends/evm/AsmCodeGen.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/Assembly.h>
#include <libevmasm/GasMeter.h>
#include <liblangutil/ErrorReporter.h>
#include <boost/range/adaptor/reversed.hpp>
#include <algorithm>
using namespace std;
using namespace dev;
using namespace langutil;
using namespace dev::eth;
using namespace dev::solidity;
namespace
{
/**
* Simple helper class to ensure that the stack height is the same at certain places in the code.
*/
class StackHeightChecker
{
public:
explicit 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: ") + to_string(m_context.stackHeight()) + " vs " + to_string(stackHeight)); }
private:
CompilerContext const& m_context;
unsigned stackHeight;
};
}
void ContractCompiler::compileContract(
ContractDefinition const& _contract,
map<ContractDefinition const*, shared_ptr<Compiler const>> const& _otherCompilers
)
{
CompilerContext::LocationSetter locationSetter(m_context, _contract);
if (_contract.isLibrary())
// Check whether this is a call (true) or a delegatecall (false).
// This has to be the first code in the contract.
appendDelegatecallCheck();
initializeContext(_contract, _otherCompilers);
// This generates the dispatch function for externally visible functions
// and adds the function to the compilation queue. Additionally internal functions,
// which are referenced directly or indirectly will be added.
appendFunctionSelector(_contract);
// This processes the above populated queue until it is empty.
appendMissingFunctions();
}
size_t ContractCompiler::compileConstructor(
ContractDefinition const& _contract,
std::map<ContractDefinition const*, shared_ptr<Compiler const>> const& _otherCompilers
)
{
CompilerContext::LocationSetter locationSetter(m_context, _contract);
if (_contract.isLibrary())
return deployLibrary(_contract);
else
{
initializeContext(_contract, _otherCompilers);
return packIntoContractCreator(_contract);
}
}
void ContractCompiler::initializeContext(
ContractDefinition const& _contract,
map<ContractDefinition const*, shared_ptr<Compiler const>> const& _otherCompilers
)
{
m_context.setExperimentalFeatures(_contract.sourceUnit().annotation().experimentalFeatures);
m_context.setOtherCompilers(_otherCompilers);
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;
// TODO: error message?
m_context.appendConditionalRevert();
}
void ContractCompiler::appendInitAndConstructorCode(ContractDefinition const& _contract)
{
solAssert(!_contract.isLibrary(), "Tried to initialize library.");
CompilerContext::LocationSetter locationSetter(m_context, _contract);
m_baseArguments = &_contract.annotation().baseConstructorArguments;
// Initialization of state variables in base-to-derived order.
for (ContractDefinition const* contract: boost::adaptors::reverse(
_contract.annotation().linearizedBaseContracts
))
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, "");
solAssert(!_contract.isLibrary(), "Tried to use contract creator or library.");
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();
CompilerContext::LocationSetter locationSetter(m_context, _contract);
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();
}
size_t ContractCompiler::deployLibrary(ContractDefinition const& _contract)
{
solAssert(!!m_runtimeCompiler, "");
solAssert(_contract.isLibrary(), "Tried to deploy contract as library.");
CompilerContext::LocationSetter locationSetter(m_context, _contract);
solAssert(m_context.runtimeSub() != size_t(-1), "Runtime sub not registered");
m_context.pushSubroutineSize(m_context.runtimeSub());
m_context.pushSubroutineOffset(m_context.runtimeSub());
// This code replaces the address added by appendDeployTimeAddress().
m_context.appendInlineAssembly(R"(
{
// If code starts at 11, an mstore(0) writes to the full PUSH20 plus data
// without the need for a shift.
let codepos := 11
codecopy(codepos, subOffset, subSize)
// Check that the first opcode is a PUSH20
if iszero(eq(0x73, byte(0, mload(codepos)))) { invalid() }
mstore(0, address())
mstore8(codepos, 0x73)
return(codepos, subSize)
}
)", {"subSize", "subOffset"});
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, "");
solAssert(m_baseArguments->count(&_constructor), "");
std::vector<ASTPointer<Expression>> const* arguments = nullptr;
ASTNode const* baseArgumentNode = m_baseArguments->at(&_constructor);
if (auto inheritanceSpecifier = dynamic_cast<InheritanceSpecifier const*>(baseArgumentNode))
arguments = inheritanceSpecifier->arguments();
else if (auto modifierInvocation = dynamic_cast<ModifierInvocation const*>(baseArgumentNode))
arguments = modifierInvocation->arguments();
solAssert(arguments, "");
solAssert(arguments->size() == constructorType.parameterTypes().size(), "");
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())
{
CompilerUtils(m_context).fetchFreeMemoryPointer();
// CODESIZE returns the actual size of the code,
// which is the size of the generated code (``programSize``)
// plus the constructor arguments added to the transaction payload.
m_context.appendProgramSize();
m_context << Instruction::CODESIZE << Instruction::SUB;
// stack: <memptr> <argument size>
m_context << Instruction::DUP1;
m_context.appendProgramSize();
m_context << Instruction::DUP4 << Instruction::CODECOPY;
// stack: <memptr> <argument size>
m_context << Instruction::DUP2 << Instruction::DUP2 << Instruction::ADD;
// stack: <memptr> <argument size> <mem end>
CompilerUtils(m_context).storeFreeMemoryPointer();
// stack: <memptr> <argument size>
CompilerUtils(m_context).abiDecode(FunctionType(_constructor).parameterTypes(), true);
}
_constructor.accept(*this);
}
void ContractCompiler::appendDelegatecallCheck()
{
// Special constant that will be replaced by the address at deploy time.
// At compilation time, this is just "PUSH20 00...000".
m_context.appendDeployTimeAddress();
m_context << Instruction::ADDRESS << Instruction::EQ;
// The result on the stack is
// "We have not been called via DELEGATECALL".
}
void ContractCompiler::appendInternalSelector(
map<FixedHash<4>, eth::AssemblyItem const> const& _entryPoints,
vector<FixedHash<4>> const& _ids,
eth::AssemblyItem const& _notFoundTag,
size_t _runs
)
{
// Code for selecting from n functions without split:
// n times: dup1, push4 <id_i>, eq, push2/3 <tag_i>, jumpi
// push2/3 <notfound> jump
// (called SELECT[n])
// Code for selecting from n functions with split:
// dup1, push4 <pivot>, gt, push2/3<tag_less>, jumpi
// SELECT[n/2]
// tag_less:
// SELECT[n/2]
//
// This means each split adds 16-18 bytes of additional code (note the additional jump out!)
// The average execution cost if we do not split at all are:
// (3 + 3 + 3 + 3 + 10) * n/2 = 24 * n/2 = 12 * n
// If we split once:
// (3 + 3 + 3 + 3 + 10) + 24 * n/4 = 24 * (n/4 + 1) = 6 * n + 24;
//
// We should split if
// _runs * 12 * n > _runs * (6 * n + 24) + 17 * createDataGas
// <=> _runs * 6 * (n - 4) > 17 * createDataGas
//
// Which also means that the execution itself is not profitable
// unless we have at least 5 functions.
// Start with some comparisons to avoid overflow, then do the actual comparison.
bool split = false;
if (_ids.size() <= 4)
split = false;
else if (_runs > (17 * eth::GasCosts::createDataGas) / 6)
split = true;
else
split = (_runs * 6 * (_ids.size() - 4) > 17 * eth::GasCosts::createDataGas);
if (split)
{
size_t pivotIndex = _ids.size() / 2;
FixedHash<4> pivot{_ids.at(pivotIndex)};
m_context << dupInstruction(1) << u256(FixedHash<4>::Arith(pivot)) << Instruction::GT;
eth::AssemblyItem lessTag{m_context.appendConditionalJump()};
// Here, we have funid >= pivot
vector<FixedHash<4>> larger{_ids.begin() + pivotIndex, _ids.end()};
appendInternalSelector(_entryPoints, larger, _notFoundTag, _runs);
m_context << lessTag;
// Here, we have funid < pivot
vector<FixedHash<4>> smaller{_ids.begin(), _ids.begin() + pivotIndex};
appendInternalSelector(_entryPoints, smaller, _notFoundTag, _runs);
}
else
{
for (auto const& id: _ids)
{
m_context << dupInstruction(1) << u256(FixedHash<4>::Arith(id)) << Instruction::EQ;
m_context.appendConditionalJumpTo(_entryPoints.at(id));
}
m_context.appendJumpTo(_notFoundTag);
}
}
namespace
{
// Helper function to check if any function is payable
bool hasPayableFunctions(ContractDefinition const& _contract)
{
FunctionDefinition const* fallback = _contract.fallbackFunction();
if (fallback && fallback->isPayable())
return true;
for (auto const& it: _contract.interfaceFunctions())
if (it.second->isPayable())
return true;
return false;
}
}
void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contract)
{
map<FixedHash<4>, FunctionTypePointer> interfaceFunctions = _contract.interfaceFunctions();
map<FixedHash<4>, eth::AssemblyItem const> callDataUnpackerEntryPoints;
if (_contract.isLibrary())
{
solAssert(m_context.stackHeight() == 1, "CALL / DELEGATECALL flag expected.");
}
FunctionDefinition const* fallback = _contract.fallbackFunction();
solAssert(!_contract.isLibrary() || !fallback, "Libraries can't have fallback functions");
bool needToAddCallvalueCheck = true;
if (!hasPayableFunctions(_contract) && !interfaceFunctions.empty() && !_contract.isLibrary())
{
appendCallValueCheck();
needToAddCallvalueCheck = false;
}
eth::AssemblyItem notFound = m_context.newTag();
// directly jump to fallback if the data is too short to contain a function selector
// also guards against short data
m_context << u256(4) << Instruction::CALLDATASIZE << Instruction::LT;
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: <can-call-non-view-functions>? <funhash>
vector<FixedHash<4>> sortedIDs;
for (auto const& it: interfaceFunctions)
{
callDataUnpackerEntryPoints.emplace(it.first, m_context.newTag());
sortedIDs.emplace_back(it.first);
}
std::sort(sortedIDs.begin(), sortedIDs.end());
appendInternalSelector(callDataUnpackerEntryPoints, sortedIDs, notFound, m_optimiserSettings.expectedExecutionsPerDeployment);
}
m_context << notFound;
if (fallback)
{
solAssert(!_contract.isLibrary(), "");
if (!fallback->isPayable() && needToAddCallvalueCheck)
appendCallValueCheck();
solAssert(fallback->isFallback(), "");
solAssert(FunctionType(*fallback).parameterTypes().empty(), "");
solAssert(FunctionType(*fallback).returnParameterTypes().empty(), "");
fallback->accept(*this);
m_context << Instruction::STOP;
}
else
// TODO: error message here?
m_context.appendRevert();
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);
if (_contract.isLibrary() && functionType->stateMutability() > StateMutability::View)
{
// If the function is not a view function and is called without DELEGATECALL,
// we revert.
m_context << dupInstruction(2);
m_context.appendConditionalRevert();
}
m_context.setStackOffset(0);
// We have to allow this for libraries, because value of the previous
// call is still visible in the delegatecall.
if (!functionType->isPayable() && !_contract.isLibrary() && needToAddCallvalueCheck)
appendCallValueCheck();
// Return tag is used to jump out of the function.
eth::AssemblyItem returnTag = m_context.pushNewTag();
if (!functionType->parameterTypes().empty())
{
// Parameter for calldataUnpacker
m_context << CompilerUtils::dataStartOffset;
m_context << Instruction::DUP1 << Instruction::CALLDATASIZE << Instruction::SUB;
CompilerUtils(m_context).abiDecode(functionType->parameterTypes());
}
m_context.appendJumpTo(
m_context.functionEntryLabel(functionType->declaration()),
eth::AssemblyItem::JumpType::IntoFunction
);
m_context << returnTag;
// Return tag and input parameters get consumed.
m_context.adjustStackOffset(
CompilerUtils(m_context).sizeOnStack(functionType->returnParameterTypes()) -
CompilerUtils(m_context).sizeOnStack(functionType->parameterTypes()) -
1
);
// Consumes the return parameters.
appendReturnValuePacker(functionType->returnParameterTypes(), _contract.isLibrary());
}
}
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.abiEncode(_typeParameters, _typeParameters, _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)
{
solAssert(!_contract.isLibrary(), "Tried to initialize state variables of library.");
for (VariableDeclaration const* variable: _contract.stateVariables())
if (variable->value() && !variable->isConstant())
ExpressionCompiler(m_context, m_optimiserSettings.runOrderLiterals).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_optimiserSettings.runOrderLiterals).appendConstStateVariableAccessor(_variableDeclaration);
else
ExpressionCompiler(m_context, m_optimiserSettings.runOrderLiterals).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]
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);
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_currentFunction = &_function;
m_modifierDepth = -1;
m_scopeStackHeight.clear();
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());
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);
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());
}
for (int i = 0; i < int(stackLayout.size()); ++i)
if (stackLayout[i] != i)
solAssert(false, "Invalid stack layout on cleanup.");
for (ASTPointer<VariableDeclaration const> const& variable: _function.parameters() + _function.returnParameters())
m_context.removeVariable(*variable);
m_context.adjustStackOffset(-(int)c_returnValuesSize);
/// The constructor and the fallback function doesn't to jump out.
if (!_function.isConstructor())
{
solAssert(m_context.numberOfLocalVariables() == 0, "");
if (!_function.isFallback())
m_context.appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
}
return false;
}
bool ContractCompiler::visit(InlineAssembly const& _inlineAssembly)
{
unsigned startStackHeight = m_context.stackHeight();
yul::ExternalIdentifierAccess identifierAccess;
identifierAccess.resolve = [&](yul::Identifier const& _identifier, yul::IdentifierContext, bool)
{
auto ref = _inlineAssembly.annotation().externalReferences.find(&_identifier);
if (ref == _inlineAssembly.annotation().externalReferences.end())
return size_t(-1);
return ref->second.valueSize;
};
identifierAccess.generateCode = [&](yul::Identifier const& _identifier, yul::IdentifierContext _context, yul::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 == yul::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, "");
yul::CodeGenerator::assemble(
_inlineAssembly.operations(),
*_inlineAssembly.annotation().analysisInfo,
*m_context.assemblyPtr(),
m_context.evmVersion(),
identifierAccess,
false,
m_optimiserSettings.optimizeStackAllocation
);
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_breakTags.emplace_back(loopEnd, m_context.stackHeight());
m_context << loopStart;
if (_whileStatement.isDoWhile())
{
eth::AssemblyItem condition = m_context.newTag();
m_continueTags.emplace_back(condition, m_context.stackHeight());
_whileStatement.body().accept(*this);
m_context << condition;
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopStart);
}
else
{
m_continueTags.emplace_back(loopStart, m_context.stackHeight());
compileExpression(_whileStatement.condition());
m_context << Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
_whileStatement.body().accept(*this);
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();
storeStackHeight(&_forStatement);
if (_forStatement.initializationExpression())
_forStatement.initializationExpression()->accept(*this);
m_breakTags.emplace_back(loopEnd, m_context.stackHeight());
m_continueTags.emplace_back(loopNext, m_context.stackHeight());
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();
// For the case where no break/return is executed:
// loop initialization variables have to be freed
popScopedVariables(&_forStatement);
checker.check();
return false;
}
bool ContractCompiler::visit(Continue const& _continueStatement)
{
CompilerContext::LocationSetter locationSetter(m_context, _continueStatement);
solAssert(!m_continueTags.empty(), "");
CompilerUtils(m_context).popAndJump(m_continueTags.back().second, m_continueTags.back().first);
return false;
}
bool ContractCompiler::visit(Break const& _breakStatement)
{
CompilerContext::LocationSetter locationSetter(m_context, _breakStatement);
solAssert(!m_breakTags.empty(), "");
CompilerUtils(m_context).popAndJump(m_breakTags.back().second, m_breakTags.back().first);
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 = TypeProvider::tuple(move(types));
else
expectedType = types.front();
compileExpression(*expression, expectedType);
for (auto const& retVariable: boost::adaptors::reverse(returnParameters))
CompilerUtils(m_context).moveToStackVariable(*retVariable);
}
CompilerUtils(m_context).popAndJump(m_returnTags.back().second, m_returnTags.back().first);
return false;
}
bool ContractCompiler::visit(Throw const&)
{
solAssert(false, "Throw statement is disallowed.");
return false;
}
bool ContractCompiler::visit(EmitStatement const& _emit)
{
CompilerContext::LocationSetter locationSetter(m_context, _emit);
StackHeightChecker checker(m_context);
compileExpression(_emit.eventCall());
checker.check();
return false;
}
bool ContractCompiler::visit(VariableDeclarationStatement const& _variableDeclarationStatement)
{
CompilerContext::LocationSetter locationSetter(m_context, _variableDeclarationStatement);
// Local variable slots are reserved when their declaration is visited,
// and freed in the end of their scope.
for (auto _decl: _variableDeclarationStatement.declarations())
if (_decl)
appendStackVariableInitialisation(*_decl);
StackHeightChecker checker(m_context);
if (Expression const* expression = _variableDeclarationStatement.initialValue())
{
CompilerUtils utils(m_context);
compileExpression(*expression);
TypePointers valueTypes;
if (auto tupleType = dynamic_cast<TupleType const*>(expression->annotation().type))
valueTypes = tupleType->components();
else
valueTypes = TypePointers{expression->annotation().type};
auto const& declarations = _variableDeclarationStatement.declarations();
solAssert(declarations.size() == valueTypes.size(), "");
for (size_t i = 0; i < declarations.size(); ++i)
{
size_t j = declarations.size() - i - 1;
solAssert(!!valueTypes[j], "");
if (VariableDeclaration const* varDecl = declarations[j].get())
{
utils.convertType(*valueTypes[j], *varDecl->annotation().type);
utils.moveToStackVariable(*varDecl);
}
else
utils.popStackElement(*valueTypes[j]);
}
}
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;
}
bool ContractCompiler::visit(Block const& _block)
{
storeStackHeight(&_block);
return true;
}
void ContractCompiler::endVisit(Block const& _block)
{
// Frees local variables declared in the scope of this block.
popScopedVariables(&_block);
}
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();
auto abiFunctions = m_context.abiFunctions().requestedFunctions();
if (!abiFunctions.first.empty())
m_context.appendInlineAssembly(
"{" + move(abiFunctions.first) + "}",
{},
abiFunctions.second,
true,
m_optimiserSettings
);
}
void ContractCompiler::appendModifierOrFunctionCode()
{
solAssert(m_currentFunction, "");
unsigned stackSurplus = 0;
Block const* codeBlock = nullptr;
vector<VariableDeclaration const*> addedVariables;
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& nonVirtualModifier = dynamic_cast<ModifierDefinition const&>(
*modifierInvocation->name()->annotation().referencedDeclaration
);
ModifierDefinition const& modifier = m_context.resolveVirtualFunctionModifier(nonVirtualModifier);
CompilerContext::LocationSetter locationSetter(m_context, modifier);
std::vector<ASTPointer<Expression>> const& modifierArguments =
modifierInvocation->arguments() ? *modifierInvocation->arguments() : std::vector<ASTPointer<Expression>>();
solAssert(modifier.parameters().size() == modifierArguments.size(), "");
for (unsigned i = 0; i < modifier.parameters().size(); ++i)
{
m_context.addVariable(*modifier.parameters()[i]);
addedVariables.push_back(modifier.parameters()[i].get());
compileExpression(
*modifierArguments[i],
modifier.parameters()[i]->annotation().type
);
}
stackSurplus = CompilerUtils::sizeOnStack(modifier.parameters());
codeBlock = &modifier.body();
}
}
if (codeBlock)
{
m_returnTags.emplace_back(m_context.newTag(), m_context.stackHeight());
codeBlock->accept(*this);
solAssert(!m_returnTags.empty(), "");
m_context << m_returnTags.back().first;
m_returnTags.pop_back();
CompilerUtils(m_context).popStackSlots(stackSurplus);
for (auto var: addedVariables)
m_context.removeVariable(*var);
}
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_optimiserSettings.runOrderLiterals);
expressionCompiler.compile(_expression);
if (_targetType)
CompilerUtils(m_context).convertType(*_expression.annotation().type, *_targetType);
}
void ContractCompiler::popScopedVariables(ASTNode const* _node)
{
unsigned blockHeight = m_scopeStackHeight.at(m_modifierDepth).at(_node);
m_context.removeVariablesAboveStackHeight(blockHeight);
solAssert(m_context.stackHeight() >= blockHeight, "");
unsigned stackDiff = m_context.stackHeight() - blockHeight;
CompilerUtils(m_context).popStackSlots(stackDiff);
m_scopeStackHeight[m_modifierDepth].erase(_node);
if (m_scopeStackHeight[m_modifierDepth].empty())
m_scopeStackHeight.erase(m_modifierDepth);
}
void ContractCompiler::storeStackHeight(ASTNode const* _node)
{
m_scopeStackHeight[m_modifierDepth][_node] = m_context.stackHeight();
}