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ContractCompiler.cpp
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ContractCompiler.cpp
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/*
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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* @author Christian <[email protected]>
* @date 2014
* Solidity compiler.
*/
#include <libsolidity/ast/AST.h>
#include <libsolidity/ast/ASTUtils.h>
#include <libsolidity/ast/TypeProvider.h>
#include <libsolidity/codegen/CompilerUtils.h>
#include <libsolidity/codegen/ContractCompiler.h>
#include <libsolidity/codegen/ExpressionCompiler.h>
#include <libyul/AsmAnalysisInfo.h>
#include <libyul/AsmAnalysis.h>
#include <libyul/AST.h>
#include <libyul/backends/evm/AsmCodeGen.h>
#include <libyul/backends/evm/EVMMetrics.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <libyul/optimiser/Suite.h>
#include <libyul/Object.h>
#include <libyul/optimiser/ASTCopier.h>
#include <libyul/YulString.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/Assembly.h>
#include <libevmasm/GasMeter.h>
#include <liblangutil/ErrorReporter.h>
#include <libsolutil/Whiskers.h>
#include <libsolutil/FunctionSelector.h>
#include <libsolutil/StackTooDeepString.h>
#include <range/v3/view/reverse.hpp>
#include <algorithm>
#include <limits>
using namespace std;
using namespace solidity;
using namespace solidity::evmasm;
using namespace solidity::frontend;
using namespace solidity::langutil;
using solidity::util::FixedHash;
using solidity::util::h256;
using solidity::util::errinfo_comment;
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);
}
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.setUseABICoderV2(*_contract.sourceUnit().annotation().useABICoderV2);
m_context.setOtherCompilers(_otherCompilers);
m_context.setMostDerivedContract(_contract);
if (m_runtimeCompiler)
registerImmutableVariables(_contract);
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.appendConditionalRevert(false, "Ether sent to non-payable function");
}
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: _contract.annotation().linearizedBaseContracts | ranges::views::reverse)
initializeStateVariables(*contract);
if (FunctionDefinition const* constructor = _contract.constructor())
appendConstructor(*constructor);
else
{
// Implicit constructors are always non-payable.
appendCallValueCheck();
if (auto c = _contract.nextConstructor(m_context.mostDerivedContract()))
appendBaseConstructor(*c);
}
}
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.
evmasm::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() != numeric_limits<size_t>::max(), "Runtime sub not registered");
ContractType contractType(_contract);
auto const& immutables = contractType.immutableVariables();
// Push all immutable values on the stack.
for (auto const& immutable: immutables)
CompilerUtils(m_context).loadFromMemory(
static_cast<unsigned>(m_context.immutableMemoryOffset(*immutable)),
*immutable->annotation().type,
false,
true
);
m_context.pushSubroutineSize(m_context.runtimeSub());
if (immutables.empty())
m_context << Instruction::DUP1;
m_context.pushSubroutineOffset(m_context.runtimeSub());
m_context << u256(0) << Instruction::CODECOPY;
// Assign immutable values from stack in reversed order.
for (auto const& immutable: immutables | ranges::views::reverse)
{
auto slotNames = m_context.immutableVariableSlotNames(*immutable);
for (auto&& slotName: slotNames | ranges::views::reverse)
{
m_context << u256(0);
m_context.appendImmutableAssignment(slotName);
}
}
if (!immutables.empty())
m_context.pushSubroutineSize(m_context.runtimeSub());
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.");
appendMissingFunctions();
m_runtimeCompiler->appendMissingFunctions();
CompilerContext::LocationSetter locationSetter(m_context, _contract);
solAssert(m_context.runtimeSub() != numeric_limits<size_t>::max(), "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(
util::Whiskers(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)))) {
mstore(0, <panicSelector>)
mstore(4, <panicCode>)
revert(0, 0x24)
}
mstore(0, address())
mstore8(codepos, 0x73)
return(codepos, subSize)
}
)")
("panicSelector", util::selectorFromSignature("Panic(uint256)").str())
("panicCode", "0")
.render(),
{"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>, evmasm::AssemblyItem const> const& _entryPoints,
vector<FixedHash<4>> const& _ids,
evmasm::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 * evmasm::GasCosts::createDataGas) / 6)
split = true;
else
split = (_runs * 6 * (_ids.size() - 4) > 17 * evmasm::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;
evmasm::AssemblyItem lessTag{m_context.appendConditionalJump()};
// Here, we have funid >= pivot
vector<FixedHash<4>> larger{_ids.begin() + static_cast<ptrdiff_t>(pivotIndex), _ids.end()};
appendInternalSelector(_entryPoints, larger, _notFoundTag, _runs);
m_context << lessTag;
// Here, we have funid < pivot
vector<FixedHash<4>> smaller{_ids.begin(), _ids.begin() + static_cast<ptrdiff_t>(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)
{
if (_contract.receiveFunction())
return true;
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>, evmasm::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");
FunctionDefinition const* etherReceiver = _contract.receiveFunction();
solAssert(!_contract.isLibrary() || !etherReceiver, "Libraries can't have ether receiver functions");
bool needToAddCallvalueCheck = true;
if (!hasPayableFunctions(_contract) && !interfaceFunctions.empty() && !_contract.isLibrary())
{
appendCallValueCheck();
needToAddCallvalueCheck = false;
}
evmasm::AssemblyItem notFoundOrReceiveEther = m_context.newTag();
// If there is neither a fallback nor a receive ether function, we only need one label to jump to, which
// always reverts.
evmasm::AssemblyItem notFound = (!fallback && !etherReceiver) ? notFoundOrReceiveEther : m_context.newTag();
// directly jump to fallback or ether receiver 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(notFoundOrReceiveEther);
// retrieve the function signature hash from the calldata
if (!interfaceFunctions.empty())
{
CompilerUtils(m_context).loadFromMemory(0, IntegerType(CompilerUtils::dataStartOffset * 8), true, false);
// 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 << notFoundOrReceiveEther;
if (!fallback && !etherReceiver)
m_context.appendRevert("Contract does not have fallback nor receive functions");
else
{
if (etherReceiver)
{
// directly jump to fallback, if there is calldata
m_context << Instruction::CALLDATASIZE;
m_context.appendConditionalJumpTo(notFound);
solAssert(!_contract.isLibrary(), "");
solAssert(etherReceiver->isReceive(), "");
solAssert(FunctionType(*etherReceiver).parameterTypes().empty(), "");
solAssert(FunctionType(*etherReceiver).returnParameterTypes().empty(), "");
etherReceiver->accept(*this);
m_context << Instruction::STOP;
}
m_context << notFound;
if (fallback)
{
solAssert(!_contract.isLibrary(), "");
if (!fallback->isPayable() && needToAddCallvalueCheck)
appendCallValueCheck();
solAssert(fallback->isFallback(), "");
m_context.setStackOffset(0);
if (!FunctionType(*fallback).parameterTypes().empty())
m_context << u256(0) << Instruction::CALLDATASIZE;
fallback->accept(*this);
if (FunctionType(*fallback).returnParameterTypes().empty())
m_context << Instruction::STOP;
else
{
m_context << Instruction::DUP1 << Instruction::MLOAD << Instruction::SWAP1;
m_context << u256(0x20) << Instruction::ADD;
m_context << Instruction::RETURN;
}
}
else
m_context.appendRevert("Unknown signature and no fallback defined");
}
for (auto const& it: interfaceFunctions)
{
m_context.setStackOffset(1);
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(false, "Non-view function of library called without DELEGATECALL");
}
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.
evmasm::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()),
evmasm::AssemblyItem::JumpType::IntoFunction
);
m_context << returnTag;
// Return tag and input parameters get consumed.
m_context.adjustStackOffset(
static_cast<int>(CompilerUtils::sizeOnStack(functionType->returnParameterTypes())) -
static_cast<int>(CompilerUtils::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::registerImmutableVariables(ContractDefinition const& _contract)
{
solAssert(m_runtimeCompiler, "Attempted to register immutables for runtime code generation.");
for (auto const& var: ContractType(_contract).immutableVariables())
m_context.addImmutable(*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)
{
solAssert(_function.isImplemented(), "");
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.isFallback())
m_context.adjustStackOffset(static_cast<int>(parametersSize));
else if (!_function.isConstructor())
// adding 1 for return address.
m_context.adjustStackOffset(static_cast<int>(parametersSize) + 1);
for (ASTPointer<VariableDeclaration> const& variable: _function.parameters())
{
m_context.addVariable(*variable, parametersSize);
parametersSize -= variable->annotation().type->sizeOnStack();
}
for (ASTPointer<VariableDeclaration> const& variable: _function.returnParameters())
appendStackVariableInitialisation(*variable, /* _provideDefaultValue = */ true);
if (_function.isConstructor())
if (auto c = dynamic_cast<ContractDefinition const&>(*_function.scope()).nextConstructor(
m_context.mostDerivedContract()
))
appendBaseConstructor(*c);
solAssert(m_returnTags.empty(), "");
m_breakTags.clear();
m_continueTags.clear();
m_currentFunction = &_function;
m_modifierDepth = numeric_limits<unsigned>::max();
m_scopeStackHeight.clear();
m_context.setModifierDepth(0);
appendModifierOrFunctionCode();
m_context.setModifierDepth(0);
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;
if (!_function.isConstructor() && !_function.isFallback())
stackLayout.push_back(static_cast<int>(c_returnValuesSize)); // target of return address
stackLayout += vector<int>(c_argumentsSize, -1); // discard all arguments
for (size_t i = 0; i < c_returnValuesSize; ++i)
stackLayout.push_back(static_cast<int>(i));
if (stackLayout.size() > 17)
BOOST_THROW_EXCEPTION(
StackTooDeepError() <<
errinfo_sourceLocation(_function.location()) <<
util::errinfo_comment(util::stackTooDeepString)
);
while (!stackLayout.empty() && stackLayout.back() != static_cast<int>(stackLayout.size() - 1))
if (stackLayout.back() < 0)
{
m_context << Instruction::POP;
stackLayout.pop_back();
}
else
{
m_context << swapInstruction(static_cast<unsigned>(stackLayout.size()) - static_cast<unsigned>(stackLayout.back()) - 1u);
swap(stackLayout[static_cast<size_t>(stackLayout.back())], stackLayout.back());
}
for (size_t i = 0; i < stackLayout.size(); ++i)
if (stackLayout[i] != static_cast<int>(i))
solAssert(false, "Invalid stack layout on cleanup.");
for (ASTPointer<VariableDeclaration> 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() && !_function.isReceive())
m_context.appendJump(evmasm::AssemblyItem::JumpType::OutOfFunction);
}
return false;
}
bool ContractCompiler::visit(InlineAssembly const& _inlineAssembly)
{
unsigned startStackHeight = m_context.stackHeight();
yul::ExternalIdentifierAccess::CodeGenerator identifierAccessCodeGen = [&](
yul::Identifier const& _identifier,
yul::IdentifierContext _context,
yul::AbstractAssembly& _assembly
)
{
solAssert(_context == yul::IdentifierContext::RValue || _context == yul::IdentifierContext::LValue, "");
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 (auto variable = dynamic_cast<VariableDeclaration const*>(decl))
{
solAssert(!variable->immutable(), "");
if (variable->isConstant())
{
variable = rootConstVariableDeclaration(*variable);
// If rootConstVariableDeclaration fails and returns nullptr,
// it should have failed in TypeChecker already, causing a compilation error.
// In such case we should not get here.
solAssert(variable, "");
u256 value;
if (variable->value()->annotation().type->category() == Type::Category::RationalNumber)
{
value = dynamic_cast<RationalNumberType const&>(*variable->value()->annotation().type).literalValue(nullptr);
if (FixedBytesType const* bytesType = dynamic_cast<FixedBytesType const*>(variable->type()))
value = value << (256 - 8 * bytesType->numBytes());
else
solAssert(variable->type()->category() == Type::Category::Integer, "");
}
else if (Literal const* literal = dynamic_cast<Literal const*>(variable->value().get()))
{
Type const* type = literal->annotation().type;
switch (type->category())
{
case Type::Category::Bool:
case Type::Category::Address:
// Either both the literal and the variable are bools, or they are both addresses.
// If they are both bools, comparing category is the same as comparing the types.
// If they are both addresses, compare category so that payable/nonpayable is not compared.
solAssert(type->category() == variable->annotation().type->category(), "");
value = type->literalValue(literal);
break;
case Type::Category::StringLiteral:
{
StringLiteralType const& stringLiteral = dynamic_cast<StringLiteralType const&>(*type);
solAssert(variable->type()->category() == Type::Category::FixedBytes, "");
unsigned const numBytes = dynamic_cast<FixedBytesType const&>(*variable->type()).numBytes();
solAssert(stringLiteral.value().size() <= numBytes, "");
value = u256(h256(stringLiteral.value(), h256::AlignLeft));
break;
}
default:
solAssert(false, "");
}
}
else
solAssert(false, "Invalid constant in inline assembly.");
m_context << value;
}
else if (m_context.isStateVariable(decl))
{
auto const& location = m_context.storageLocationOfVariable(*decl);
if (ref->second.suffix == "slot")
m_context << location.first;
else if (ref->second.suffix == "offset")
m_context << u256(location.second);
else
solAssert(false, "");
}
else if (m_context.isLocalVariable(decl))
{
unsigned stackDiff = static_cast<unsigned>(_assembly.stackHeight()) - m_context.baseStackOffsetOfVariable(*variable);
if (!ref->second.suffix.empty())
{
string const& suffix = ref->second.suffix;
if (variable->type()->dataStoredIn(DataLocation::Storage))
{
solAssert(suffix == "offset" || suffix == "slot", "");
unsigned size = variable->type()->sizeOnStack();
if (size == 2)
{
// slot plus offset
if (suffix == "offset")
stackDiff--;
}
else
{
solAssert(size == 1, "");
// only slot, offset is zero
if (suffix == "offset")
{
_assembly.appendConstant(u256(0));
return;
}
}
}
else if (variable->type()->dataStoredIn(DataLocation::CallData))
{
auto const* arrayType = dynamic_cast<ArrayType const*>(variable->type());
solAssert(
arrayType && arrayType->isDynamicallySized() && arrayType->dataStoredIn(DataLocation::CallData),
""
);
solAssert(suffix == "offset" || suffix == "length", "");
solAssert(variable->type()->sizeOnStack() == 2, "");
if (suffix == "length")
stackDiff--;
}
else if (
auto const* functionType = dynamic_cast<FunctionType const*>(variable->type());
functionType && functionType->kind() == FunctionType::Kind::External
)
{
solAssert(suffix == "selector" || suffix == "address", "");
solAssert(variable->type()->sizeOnStack() == 2, "");
if (suffix == "selector")
stackDiff--;
}
else
solAssert(false, "");
}
else
solAssert(variable->type()->sizeOnStack() == 1, "");
if (stackDiff < 1 || stackDiff > 16)
BOOST_THROW_EXCEPTION(
StackTooDeepError() <<
errinfo_sourceLocation(_inlineAssembly.location()) <<
util::errinfo_comment(util::stackTooDeepString)
);
_assembly.appendInstruction(dupInstruction(stackDiff));
}
else
solAssert(false, "");
}
else if (auto contract = dynamic_cast<ContractDefinition const*>(decl))
{
solAssert(ref->second.suffix.empty(), "");
solAssert(contract->isLibrary(), "");
_assembly.appendLinkerSymbol(contract->fullyQualifiedName());
}
else
solAssert(false, "Invalid declaration type.");
solAssert(_assembly.stackHeight() - depositBefore == static_cast<int>(ref->second.valueSize), "");
}
else
{
// lvalue context
auto variable = dynamic_cast<VariableDeclaration const*>(decl);
unsigned stackDiff = static_cast<unsigned>(_assembly.stackHeight()) - m_context.baseStackOffsetOfVariable(*variable) - 1;
string const& suffix = ref->second.suffix;
if (variable->type()->dataStoredIn(DataLocation::Storage))
{
solAssert(
!!variable && m_context.isLocalVariable(variable),
"Can only assign to stack variables in inline assembly."
);
solAssert(variable->type()->sizeOnStack() == 1, "");
solAssert(suffix == "slot", "");
}
else if (variable->type()->dataStoredIn(DataLocation::CallData))
{
if (auto const* arrayType = dynamic_cast<ArrayType const*>(variable->type()))
{
if (arrayType->isDynamicallySized())
{
solAssert(suffix == "offset" || suffix == "length", "");
solAssert(variable->type()->sizeOnStack() == 2, "");
if (suffix == "length")
stackDiff--;
}
else
{
solAssert(variable->type()->sizeOnStack() == 1, "");
solAssert(suffix.empty(), "");
}
}
else
{
auto const* structType = dynamic_cast<StructType const*>(variable->type());
solAssert(structType, "");
solAssert(variable->type()->sizeOnStack() == 1, "");
solAssert(suffix.empty(), "");
}
}
else if (
auto const* functionType = dynamic_cast<FunctionType const*>(variable->type());
functionType && functionType->kind() == FunctionType::Kind::External
)
{
solAssert(suffix == "selector" || suffix == "address", "");
solAssert(variable->type()->sizeOnStack() == 2, "");
if (suffix == "selector")
stackDiff--;
}
else
solAssert(suffix.empty(), "");
if (stackDiff > 16 || stackDiff < 1)
BOOST_THROW_EXCEPTION(
StackTooDeepError() <<
errinfo_sourceLocation(_inlineAssembly.location()) <<
util::errinfo_comment(util::stackTooDeepString)
);
_assembly.appendInstruction(swapInstruction(stackDiff));
_assembly.appendInstruction(Instruction::POP);
}
};
yul::Block const* code = &_inlineAssembly.operations();
yul::AsmAnalysisInfo* analysisInfo = _inlineAssembly.annotation().analysisInfo.get();
// Only used in the scope below, but required to live outside to keep the
// shared_ptr's alive
yul::Object object = {};
// The optimiser cannot handle external references
if (
m_optimiserSettings.runYulOptimiser &&
_inlineAssembly.annotation().externalReferences.empty()
)
{
yul::EVMDialect const* dialect = dynamic_cast<decltype(dialect)>(&_inlineAssembly.dialect());
solAssert(dialect, "");
// Create a modifiable copy of the code and analysis
object.code = make_shared<yul::Block>(yul::ASTCopier().translate(*code));
object.analysisInfo = make_shared<yul::AsmAnalysisInfo>(yul::AsmAnalyzer::analyzeStrictAssertCorrect(*dialect, object));
m_context.optimizeYul(object, *dialect, m_optimiserSettings);
code = object.code.get();
analysisInfo = object.analysisInfo.get();
}
yul::CodeGenerator::assemble(
*code,
*analysisInfo,
*m_context.assemblyPtr(),
m_context.evmVersion(),
identifierAccessCodeGen,
false,
m_optimiserSettings.optimizeStackAllocation
);
m_context.setStackOffset(static_cast<int>(startStackHeight));
return false;
}
bool ContractCompiler::visit(TryStatement const& _tryStatement)
{
StackHeightChecker checker(m_context);
CompilerContext::LocationSetter locationSetter(m_context, _tryStatement);
compileExpression(_tryStatement.externalCall());
int const returnSize = static_cast<int>(_tryStatement.externalCall().annotation().type->sizeOnStack());
// Stack: [ return values] <success flag>
evmasm::AssemblyItem successTag = m_context.appendConditionalJump();
// Catch case.
m_context.adjustStackOffset(-returnSize);
handleCatch(_tryStatement.clauses());
evmasm::AssemblyItem endTag = m_context.appendJumpToNew();
m_context << successTag;
m_context.adjustStackOffset(returnSize);
{
// Success case.
// Stack: return values
TryCatchClause const& successClause = *_tryStatement.clauses().front();
if (successClause.parameters())
{
vector<Type const*> exprTypes{_tryStatement.externalCall().annotation().type};
if (auto tupleType = dynamic_cast<TupleType const*>(exprTypes.front()))
exprTypes = tupleType->components();
vector<ASTPointer<VariableDeclaration>> const& params = successClause.parameters()->parameters();
solAssert(exprTypes.size() == params.size(), "");
for (size_t i = 0; i < exprTypes.size(); ++i)
solAssert(params[i] && exprTypes[i] && *params[i]->annotation().type == *exprTypes[i], "");
}
else