solidity/test/tools/yulInterpreter/Interpreter.cpp
2020-01-16 16:18:08 +00:00

324 lines
8.9 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/>.
*/
/**
* Yul interpreter.
*/
#include <test/tools/yulInterpreter/Interpreter.h>
#include <test/tools/yulInterpreter/EVMInstructionInterpreter.h>
#include <test/tools/yulInterpreter/EwasmBuiltinInterpreter.h>
#include <libyul/AsmData.h>
#include <libyul/Dialect.h>
#include <libyul/Utilities.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <libyul/backends/wasm/WasmDialect.h>
#include <liblangutil/Exceptions.h>
#include <libsolutil/FixedHash.h>
#include <boost/range/adaptor/reversed.hpp>
#include <boost/algorithm/cxx11/all_of.hpp>
#include <ostream>
#include <variant>
using namespace std;
using namespace solidity;
using namespace solidity::yul;
using namespace solidity::yul::test;
using solidity::util::h256;
void InterpreterState::dumpTraceAndState(ostream& _out) const
{
_out << "Trace:" << endl;
for (auto const& line: trace)
_out << " " << line << endl;
_out << "Memory dump:\n";
map<u256, u256> words;
for (auto const& [offset, value]: memory)
words[(offset / 0x20) * 0x20] |= u256(uint32_t(value)) << (256 - 8 - 8 * size_t(offset % 0x20));
for (auto const& [offset, value]: words)
if (value != 0)
_out << " " << std::uppercase << std::hex << std::setw(4) << offset << ": " << h256(value).hex() << endl;
_out << "Storage dump:" << endl;
for (auto const& slot: storage)
if (slot.second != h256{})
_out << " " << slot.first.hex() << ": " << slot.second.hex() << endl;
}
void Interpreter::operator()(ExpressionStatement const& _expressionStatement)
{
evaluateMulti(_expressionStatement.expression);
}
void Interpreter::operator()(Assignment const& _assignment)
{
solAssert(_assignment.value, "");
vector<u256> values = evaluateMulti(*_assignment.value);
solAssert(values.size() == _assignment.variableNames.size(), "");
for (size_t i = 0; i < values.size(); ++i)
{
YulString varName = _assignment.variableNames.at(i).name;
solAssert(m_variables.count(varName), "");
m_variables[varName] = values.at(i);
}
}
void Interpreter::operator()(VariableDeclaration const& _declaration)
{
vector<u256> values(_declaration.variables.size(), 0);
if (_declaration.value)
values = evaluateMulti(*_declaration.value);
solAssert(values.size() == _declaration.variables.size(), "");
for (size_t i = 0; i < values.size(); ++i)
{
YulString varName = _declaration.variables.at(i).name;
solAssert(!m_variables.count(varName), "");
m_variables[varName] = values.at(i);
solAssert(!m_scopes.back().count(varName), "");
m_scopes.back().emplace(varName, nullptr);
}
}
void Interpreter::operator()(If const& _if)
{
solAssert(_if.condition, "");
if (evaluate(*_if.condition) != 0)
(*this)(_if.body);
}
void Interpreter::operator()(Switch const& _switch)
{
solAssert(_switch.expression, "");
u256 val = evaluate(*_switch.expression);
solAssert(!_switch.cases.empty(), "");
for (auto const& c: _switch.cases)
// Default case has to be last.
if (!c.value || evaluate(*c.value) == val)
{
(*this)(c.body);
break;
}
}
void Interpreter::operator()(FunctionDefinition const&)
{
}
void Interpreter::operator()(ForLoop const& _forLoop)
{
solAssert(_forLoop.condition, "");
openScope();
ScopeGuard g([this]{ closeScope(); });
for (auto const& statement: _forLoop.pre.statements)
{
visit(statement);
if (m_state.controlFlowState == ControlFlowState::Leave)
return;
}
while (evaluate(*_forLoop.condition) != 0)
{
m_state.controlFlowState = ControlFlowState::Default;
(*this)(_forLoop.body);
if (m_state.controlFlowState == ControlFlowState::Break || m_state.controlFlowState == ControlFlowState::Leave)
break;
m_state.controlFlowState = ControlFlowState::Default;
(*this)(_forLoop.post);
if (m_state.controlFlowState == ControlFlowState::Leave)
break;
}
if (m_state.controlFlowState != ControlFlowState::Leave)
m_state.controlFlowState = ControlFlowState::Default;
}
void Interpreter::operator()(Break const&)
{
m_state.controlFlowState = ControlFlowState::Break;
}
void Interpreter::operator()(Continue const&)
{
m_state.controlFlowState = ControlFlowState::Continue;
}
void Interpreter::operator()(Leave const&)
{
m_state.controlFlowState = ControlFlowState::Leave;
}
void Interpreter::operator()(Block const& _block)
{
m_state.numSteps++;
if (m_state.maxSteps > 0 && m_state.numSteps >= m_state.maxSteps)
{
m_state.trace.emplace_back("Interpreter execution step limit reached.");
throw StepLimitReached();
}
openScope();
// Register functions.
for (auto const& statement: _block.statements)
if (holds_alternative<FunctionDefinition>(statement))
{
FunctionDefinition const& funDef = std::get<FunctionDefinition>(statement);
solAssert(!m_scopes.back().count(funDef.name), "");
m_scopes.back().emplace(funDef.name, &funDef);
}
for (auto const& statement: _block.statements)
{
visit(statement);
if (m_state.controlFlowState != ControlFlowState::Default)
break;
}
closeScope();
}
u256 Interpreter::evaluate(Expression const& _expression)
{
ExpressionEvaluator ev(m_state, m_dialect, m_variables, m_scopes);
ev.visit(_expression);
return ev.value();
}
vector<u256> Interpreter::evaluateMulti(Expression const& _expression)
{
ExpressionEvaluator ev(m_state, m_dialect, m_variables, m_scopes);
ev.visit(_expression);
return ev.values();
}
void Interpreter::closeScope()
{
for (auto const& [var, funDeclaration]: m_scopes.back())
if (!funDeclaration)
solAssert(m_variables.erase(var) == 1, "");
m_scopes.pop_back();
}
void ExpressionEvaluator::operator()(Literal const& _literal)
{
static YulString const trueString("true");
static YulString const falseString("false");
setValue(valueOfLiteral(_literal));
}
void ExpressionEvaluator::operator()(Identifier const& _identifier)
{
solAssert(m_variables.count(_identifier.name), "");
setValue(m_variables.at(_identifier.name));
}
void ExpressionEvaluator::operator()(FunctionCall const& _funCall)
{
evaluateArgs(_funCall.arguments);
if (EVMDialect const* dialect = dynamic_cast<EVMDialect const*>(&m_dialect))
{
if (BuiltinFunctionForEVM const* fun = dialect->builtin(_funCall.functionName.name))
{
EVMInstructionInterpreter interpreter(m_state);
setValue(interpreter.evalBuiltin(*fun, values()));
return;
}
}
else if (WasmDialect const* dialect = dynamic_cast<WasmDialect const*>(&m_dialect))
if (dialect->builtin(_funCall.functionName.name))
{
EwasmBuiltinInterpreter interpreter(m_state);
setValue(interpreter.evalBuiltin(_funCall.functionName.name, values()));
return;
}
auto [functionScopes, fun] = findFunctionAndScope(_funCall.functionName.name);
solAssert(fun, "Function not found.");
solAssert(m_values.size() == fun->parameters.size(), "");
map<YulString, u256> variables;
for (size_t i = 0; i < fun->parameters.size(); ++i)
variables[fun->parameters.at(i).name] = m_values.at(i);
for (size_t i = 0; i < fun->returnVariables.size(); ++i)
variables[fun->returnVariables.at(i).name] = 0;
m_state.controlFlowState = ControlFlowState::Default;
Interpreter interpreter(m_state, m_dialect, variables, functionScopes);
interpreter(fun->body);
m_state.controlFlowState = ControlFlowState::Default;
m_values.clear();
for (auto const& retVar: fun->returnVariables)
m_values.emplace_back(interpreter.valueOfVariable(retVar.name));
}
u256 ExpressionEvaluator::value() const
{
solAssert(m_values.size() == 1, "");
return m_values.front();
}
void ExpressionEvaluator::setValue(u256 _value)
{
m_values.clear();
m_values.emplace_back(std::move(_value));
}
void ExpressionEvaluator::evaluateArgs(vector<Expression> const& _expr)
{
vector<u256> values;
/// Function arguments are evaluated in reverse.
for (auto const& expr: _expr | boost::adaptors::reversed)
{
visit(expr);
values.push_back(value());
}
m_values = std::move(values);
std::reverse(m_values.begin(), m_values.end());
}
pair<
vector<map<YulString, FunctionDefinition const*>>,
FunctionDefinition const*
> ExpressionEvaluator::findFunctionAndScope(YulString _functionName) const
{
FunctionDefinition const* fun = nullptr;
std::vector<std::map<YulString, FunctionDefinition const*>> newScopes;
for (auto const& scope: m_scopes)
{
// Copy over all functions.
newScopes.push_back({});
for (auto const& [name, funDef]: scope)
if (funDef)
newScopes.back().emplace(name, funDef);
// Stop at the called function.
if (scope.count(_functionName))
{
fun = scope.at(_functionName);
break;
}
}
return {move(newScopes), fun};
}