/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2014
* Solidity compiler.
*/
#include <algorithm>
#include <boost/range/adaptor/reversed.hpp>
#include <libevmcore/Instruction.h>
#include <libevmcore/Assembly.h>
#include <libsolidity/AST.h>
#include <libsolidity/Compiler.h>
#include <libsolidity/ExpressionCompiler.h>
#include <libsolidity/CompilerUtils.h>
#include <libsolidity/CallGraph.h>
using namespace std;
namespace dev {
namespace solidity {
void Compiler::compileContract(ContractDefinition const& _contract,
map<ContractDefinition const*, bytes const*> const& _contracts)
{
m_context = CompilerContext(); // clear it just in case
initializeContext(_contract, _contracts);
for (ContractDefinition const* contract: _contract.getLinearizedBaseContracts())
{
for (auto const& it: contract->getInterfaceFunctions())
{
auto funcDef = it.second.getFunctionDefinition();
if (funcDef && funcDef->isConstructor())
continue;
m_context.addFunction(*it.second.getDeclaration());
}
for (ASTPointer<ModifierDefinition> const& modifier: contract->getFunctionModifiers())
m_context.addModifier(*modifier);
}
appendFunctionSelector(_contract);
for (ContractDefinition const* contract: _contract.getLinearizedBaseContracts())
for (ASTPointer<FunctionDefinition> const& function: contract->getDefinedFunctions())
if (!function->isConstructor())
function->accept(*this);
// Swap the runtime context with the creation-time context
swap(m_context, m_runtimeContext);
initializeContext(_contract, _contracts);
packIntoContractCreator(_contract, m_runtimeContext);
}
void Compiler::initializeContext(ContractDefinition const& _contract,
map<ContractDefinition const*, bytes const*> const& _contracts)
{
m_context.setCompiledContracts(_contracts);
registerStateVariables(_contract);
}
void Compiler::packIntoContractCreator(ContractDefinition const& _contract, CompilerContext const& _runtimeContext)
{
std::vector<ContractDefinition const*> const& bases = _contract.getLinearizedBaseContracts();
// Make all modifiers known to the context.
for (ContractDefinition const* contract: bases)
for (ASTPointer<ModifierDefinition> const& modifier: contract->getFunctionModifiers())
m_context.addModifier(*modifier);
// arguments for base constructors, filled in derived-to-base order
map<ContractDefinition const*, vector<ASTPointer<Expression>> const*> baseArguments;
set<FunctionDefinition const*> neededFunctions;
set<ASTNode const*> nodesUsedInConstructors;
// Determine the arguments that are used for the base constructors and also which functions
// are needed at compile time.
for (ContractDefinition const* contract: bases)
{
if (FunctionDefinition const* constructor = contract->getConstructor())
nodesUsedInConstructors.insert(constructor);
for (ASTPointer<InheritanceSpecifier> const& base: contract->getBaseContracts())
{
ContractDefinition const* baseContract = dynamic_cast<ContractDefinition const*>(
base->getName()->getReferencedDeclaration());
solAssert(baseContract, "");
if (baseArguments.count(baseContract) == 0)
{
baseArguments[baseContract] = &base->getArguments();
for (ASTPointer<Expression> const& arg: base->getArguments())
nodesUsedInConstructors.insert(arg.get());
}
}
}
auto functionOverrideResolver = [&](string const& _name) -> FunctionDefinition const*
{
for (ContractDefinition const* contract: bases)
for (ASTPointer<FunctionDefinition> const& function: contract->getDefinedFunctions())
if (!function->isConstructor() && function->getName() == _name)
return function.get();
return nullptr;
};
auto modifierOverrideResolver = [&](string const& _name) -> ModifierDefinition const*
{
return &m_context.getFunctionModifier(_name);
};
neededFunctions = getFunctionsCalled(nodesUsedInConstructors, functionOverrideResolver,
modifierOverrideResolver);
// First add all overrides (or the functions themselves if there is no override)
for (FunctionDefinition const* fun: neededFunctions)
{
FunctionDefinition const* override = nullptr;
if (!fun->isConstructor())
override = functionOverrideResolver(fun->getName());
if (!!override && neededFunctions.count(override))
m_context.addFunction(*override);
}
// now add the rest
for (FunctionDefinition const* fun: neededFunctions)
if (fun->isConstructor() || functionOverrideResolver(fun->getName()) != fun)
m_context.addFunction(*fun);
// Call constructors in base-to-derived order.
// The Constructor for the most derived contract is called later.
for (unsigned i = 1; i < bases.size(); i++)
{
ContractDefinition const* base = bases[bases.size() - i];
solAssert(base, "");
FunctionDefinition const* baseConstructor = base->getConstructor();
if (!baseConstructor)
continue;
solAssert(baseArguments[base], "");
appendBaseConstructorCall(*baseConstructor, *baseArguments[base]);
}
if (_contract.getConstructor())
appendConstructorCall(*_contract.getConstructor());
eth::AssemblyItem sub = m_context.addSubroutine(_runtimeContext.getAssembly());
// stack contains sub size
m_context << eth::Instruction::DUP1 << sub << u256(0) << eth::Instruction::CODECOPY;
m_context << u256(0) << eth::Instruction::RETURN;
// note that we have to explicitly include all used functions because of absolute jump
// labels
for (FunctionDefinition const* fun: neededFunctions)
fun->accept(*this);
}
void Compiler::appendBaseConstructorCall(FunctionDefinition const& _constructor,
vector<ASTPointer<Expression>> const& _arguments)
{
FunctionType constructorType(_constructor);
eth::AssemblyItem returnLabel = m_context.pushNewTag();
for (unsigned i = 0; i < _arguments.size(); ++i)
compileExpression(*_arguments[i], constructorType.getParameterTypes()[i]);
m_context.appendJumpTo(m_context.getFunctionEntryLabel(_constructor));
m_context << returnLabel;
}
void Compiler::appendConstructorCall(FunctionDefinition const& _constructor)
{
eth::AssemblyItem returnTag = m_context.pushNewTag();
// copy constructor arguments from code to memory and then to stack, they are supplied after the actual program
unsigned argumentSize = 0;
for (ASTPointer<VariableDeclaration> const& var: _constructor.getParameters())
argumentSize += CompilerUtils::getPaddedSize(var->getType()->getCalldataEncodedSize());
if (argumentSize > 0)
{
m_context << u256(argumentSize);
m_context.appendProgramSize();
m_context << u256(CompilerUtils::dataStartOffset); // copy it to byte four as expected for ABI calls
m_context << eth::Instruction::CODECOPY;
appendCalldataUnpacker(FunctionType(_constructor).getParameterTypes(), true);
}
m_context.appendJumpTo(m_context.getFunctionEntryLabel(_constructor));
m_context << returnTag;
}
set<FunctionDefinition const*> Compiler::getFunctionsCalled(set<ASTNode const*> const& _nodes,
function<FunctionDefinition const*(string const&)> const& _resolveFunctionOverrides,
function<ModifierDefinition const*(string const&)> const& _resolveModifierOverrides)
{
CallGraph callgraph(_resolveFunctionOverrides, _resolveModifierOverrides);
for (ASTNode const* node: _nodes)
callgraph.addNode(*node);
return callgraph.getCalls();
}
void Compiler::appendFunctionSelector(ContractDefinition const& _contract)
{
map<FixedHash<4>, FunctionDescription> interfaceFunctions = _contract.getInterfaceFunctions();
map<FixedHash<4>, const eth::AssemblyItem> callDataUnpackerEntryPoints;
// retrieve the function signature hash from the calldata
m_context << u256(1) << u256(0);
CompilerUtils(m_context).loadFromMemory(0, 4, false, true);
// stack now is: 1 0 <funhash>
for (auto const& it: interfaceFunctions)
{
callDataUnpackerEntryPoints.insert(std::make_pair(it.first, m_context.newTag()));
m_context << eth::dupInstruction(1) << u256(FixedHash<4>::Arith(it.first)) << eth::Instruction::EQ;
m_context.appendConditionalJumpTo(callDataUnpackerEntryPoints.at(it.first));
}
m_context << eth::Instruction::STOP; // function not found
for (auto const& it: interfaceFunctions)
{
FunctionType const* functionType = it.second.getFunctionType();
m_context << callDataUnpackerEntryPoints.at(it.first);
eth::AssemblyItem returnTag = m_context.pushNewTag();
appendCalldataUnpacker(functionType->getParameterTypes());
m_context.appendJumpTo(m_context.getFunctionEntryLabel(*it.second.getDeclaration()));
m_context << returnTag;
appendReturnValuePacker(functionType->getReturnParameterTypes());
}
}
unsigned Compiler::appendCalldataUnpacker(TypePointers const& _typeParameters, bool _fromMemory)
{
// We do not check the calldata size, everything is zero-padded.
unsigned dataOffset = CompilerUtils::dataStartOffset; // the 4 bytes of the function hash signature
//@todo this can be done more efficiently, saving some CALLDATALOAD calls
for (TypePointer const& type: _typeParameters)
{
unsigned const c_numBytes = type->getCalldataEncodedSize();
if (c_numBytes > 32)
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_comment("Type " + type->toString() + " not yet supported."));
bool const c_leftAligned = type->getCategory() == Type::Category::STRING;
bool const c_padToWords = true;
dataOffset += CompilerUtils(m_context).loadFromMemory(dataOffset, c_numBytes, c_leftAligned,
!_fromMemory, c_padToWords);
}
return dataOffset;
}
void Compiler::appendReturnValuePacker(TypePointers const& _typeParameters)
{
//@todo this can be also done more efficiently
unsigned dataOffset = 0;
unsigned stackDepth = 0;
for (TypePointer const& type: _typeParameters)
stackDepth += type->getSizeOnStack();
for (TypePointer const& type: _typeParameters)
{
unsigned numBytes = type->getCalldataEncodedSize();
if (numBytes > 32)
BOOST_THROW_EXCEPTION(CompilerError()
<< errinfo_comment("Type " + type->toString() + " not yet supported."));
CompilerUtils(m_context).copyToStackTop(stackDepth, *type);
ExpressionCompiler::appendTypeConversion(m_context, *type, *type, true);
bool const c_leftAligned = type->getCategory() == Type::Category::STRING;
bool const c_padToWords = true;
dataOffset += CompilerUtils(m_context).storeInMemory(dataOffset, numBytes, c_leftAligned, c_padToWords);
stackDepth -= type->getSizeOnStack();
}
// note that the stack is not cleaned up here
m_context << u256(dataOffset) << u256(0) << eth::Instruction::RETURN;
}
void Compiler::registerStateVariables(ContractDefinition const& _contract)
{
for (ContractDefinition const* contract: boost::adaptors::reverse(_contract.getLinearizedBaseContracts()))
for (ASTPointer<VariableDeclaration> const& variable: contract->getStateVariables())
m_context.addStateVariable(*variable);
}
bool Compiler::visit(FunctionDefinition const& _function)
{
//@todo to simplify this, the calling convention could by changed such that
// caller puts: [retarg0] ... [retargm] [return address] [arg0] ... [argn]
// although note that this reduces the size of the visible stack
m_context.startNewFunction();
m_returnTag = m_context.newTag();
m_breakTags.clear();
m_continueTags.clear();
m_stackCleanupForReturn = 0;
m_currentFunction = &_function;
m_modifierDepth = 0;
m_context << m_context.getFunctionEntryLabel(_function);
// stack upon entry: [return address] [arg0] [arg1] ... [argn]
// reserve additional slots: [retarg0] ... [retargm] [localvar0] ... [localvarp]
unsigned parametersSize = CompilerUtils::getSizeOnStack(_function.getParameters());
m_context.adjustStackOffset(parametersSize);
for (ASTPointer<VariableDeclaration const> const& variable: _function.getParameters())
{
m_context.addVariable(*variable, parametersSize);
parametersSize -= variable->getType()->getSizeOnStack();
}
for (ASTPointer<VariableDeclaration const> const& variable: _function.getReturnParameters())
m_context.addAndInitializeVariable(*variable);
for (VariableDeclaration const* localVariable: _function.getLocalVariables())
m_context.addAndInitializeVariable(*localVariable);
appendModifierOrFunctionCode();
m_context << m_returnTag;
// 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::getSizeOnStack(_function.getParameters());
unsigned const c_returnValuesSize = CompilerUtils::getSizeOnStack(_function.getReturnParameters());
unsigned const c_localVariablesSize = CompilerUtils::getSizeOnStack(_function.getLocalVariables());
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);
while (stackLayout.back() != int(stackLayout.size() - 1))
if (stackLayout.back() < 0)
{
m_context << eth::Instruction::POP;
stackLayout.pop_back();
}
else
{
m_context << eth::swapInstruction(stackLayout.size() - stackLayout.back() - 1);
swap(stackLayout[stackLayout.back()], stackLayout.back());
}
//@todo assert that everything is in place now
m_context << eth::Instruction::JUMP;
return false;
}
bool Compiler::visit(IfStatement const& _ifStatement)
{
compileExpression(_ifStatement.getCondition());
eth::AssemblyItem trueTag = m_context.appendConditionalJump();
if (_ifStatement.getFalseStatement())
_ifStatement.getFalseStatement()->accept(*this);
eth::AssemblyItem endTag = m_context.appendJumpToNew();
m_context << trueTag;
_ifStatement.getTrueStatement().accept(*this);
m_context << endTag;
return false;
}
bool Compiler::visit(WhileStatement const& _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;
compileExpression(_whileStatement.getCondition());
m_context << eth::Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
_whileStatement.getBody().accept(*this);
m_context.appendJumpTo(loopStart);
m_context << loopEnd;
m_continueTags.pop_back();
m_breakTags.pop_back();
return false;
}
bool Compiler::visit(ForStatement const& _forStatement)
{
eth::AssemblyItem loopStart = m_context.newTag();
eth::AssemblyItem loopEnd = m_context.newTag();
m_continueTags.push_back(loopStart);
m_breakTags.push_back(loopEnd);
if (_forStatement.getInitializationExpression())
_forStatement.getInitializationExpression()->accept(*this);
m_context << loopStart;
// if there is no terminating condition in for, default is to always be true
if (_forStatement.getCondition())
{
compileExpression(*_forStatement.getCondition());
m_context << eth::Instruction::ISZERO;
m_context.appendConditionalJumpTo(loopEnd);
}
_forStatement.getBody().accept(*this);
// for's loop expression if existing
if (_forStatement.getLoopExpression())
_forStatement.getLoopExpression()->accept(*this);
m_context.appendJumpTo(loopStart);
m_context << loopEnd;
m_continueTags.pop_back();
m_breakTags.pop_back();
return false;
}
bool Compiler::visit(Continue const&)
{
if (!m_continueTags.empty())
m_context.appendJumpTo(m_continueTags.back());
return false;
}
bool Compiler::visit(Break const&)
{
if (!m_breakTags.empty())
m_context.appendJumpTo(m_breakTags.back());
return false;
}
bool Compiler::visit(Return const& _return)
{
//@todo modifications are needed to make this work with functions returning multiple values
if (Expression const* expression = _return.getExpression())
{
solAssert(_return.getFunctionReturnParameters(), "Invalid return parameters pointer.");
VariableDeclaration const& firstVariable = *_return.getFunctionReturnParameters()->getParameters().front();
compileExpression(*expression, firstVariable.getType());
CompilerUtils(m_context).moveToStackVariable(firstVariable);
}
for (unsigned i = 0; i < m_stackCleanupForReturn; ++i)
m_context << eth::Instruction::POP;
m_context.appendJumpTo(m_returnTag);
m_context.adjustStackOffset(m_stackCleanupForReturn);
return false;
}
bool Compiler::visit(VariableDefinition const& _variableDefinition)
{
if (Expression const* expression = _variableDefinition.getExpression())
{
compileExpression(*expression, _variableDefinition.getDeclaration().getType());
CompilerUtils(m_context).moveToStackVariable(_variableDefinition.getDeclaration());
}
return false;
}
bool Compiler::visit(ExpressionStatement const& _expressionStatement)
{
Expression const& expression = _expressionStatement.getExpression();
compileExpression(expression);
CompilerUtils(m_context).popStackElement(*expression.getType());
return false;
}
bool Compiler::visit(PlaceholderStatement const&)
{
++m_modifierDepth;
appendModifierOrFunctionCode();
--m_modifierDepth;
return true;
}
void Compiler::appendModifierOrFunctionCode()
{
solAssert(m_currentFunction, "");
if (m_modifierDepth >= m_currentFunction->getModifiers().size())
m_currentFunction->getBody().accept(*this);
else
{
ASTPointer<ModifierInvocation> const& modifierInvocation = m_currentFunction->getModifiers()[m_modifierDepth];
ModifierDefinition const& modifier = m_context.getFunctionModifier(modifierInvocation->getName()->getName());
solAssert(modifier.getParameters().size() == modifierInvocation->getArguments().size(), "");
for (unsigned i = 0; i < modifier.getParameters().size(); ++i)
{
m_context.addVariable(*modifier.getParameters()[i]);
compileExpression(*modifierInvocation->getArguments()[i],
modifier.getParameters()[i]->getType());
}
for (VariableDeclaration const* localVariable: modifier.getLocalVariables())
m_context.addAndInitializeVariable(*localVariable);
unsigned const c_stackSurplus = CompilerUtils::getSizeOnStack(modifier.getParameters()) +
CompilerUtils::getSizeOnStack(modifier.getLocalVariables());
m_stackCleanupForReturn += c_stackSurplus;
modifier.getBody().accept(*this);
for (unsigned i = 0; i < c_stackSurplus; ++i)
m_context << eth::Instruction::POP;
m_stackCleanupForReturn -= c_stackSurplus;
}
}
void Compiler::compileExpression(Expression const& _expression, TypePointer const& _targetType)
{
ExpressionCompiler::compileExpression(m_context, _expression, m_optimize);
if (_targetType)
ExpressionCompiler::appendTypeConversion(m_context, *_expression.getType(), *_targetType);
}
}
}
