solidity/libyul/optimiser/SyntacticalEquality.cpp
Christian Parpart 065c3c87af
libyul: changing some AST members from shared_ptr<> to unique_ptr<>
* Some spaces look a little more verbose now, but that shouln't be a problem as it also should raise readability, too.
* This makes some use of return-value-optimizations also.
2019-01-16 14:58:59 +01:00

196 lines
6.8 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/>.
*/
/**
* Component that can compare ASTs for equality on a syntactic basis.
*/
#include <libyul/optimiser/SyntacticalEquality.h>
#include <libyul/Exceptions.h>
#include <libyul/AsmData.h>
#include <libyul/Utilities.h>
#include <libdevcore/CommonData.h>
using namespace std;
using namespace dev;
using namespace yul;
bool SyntacticallyEqual::operator()(Expression const& _lhs, Expression const& _rhs)
{
return boost::apply_visitor([this](auto&& _lhsExpr, auto&& _rhsExpr) -> bool {
// ``this->`` is redundant, but required to work around a bug present in gcc 6.x.
return this->expressionEqual(_lhsExpr, _rhsExpr);
}, _lhs, _rhs);
}
bool SyntacticallyEqual::operator()(Statement const& _lhs, Statement const& _rhs)
{
return boost::apply_visitor([this](auto&& _lhsStmt, auto&& _rhsStmt) -> bool {
// ``this->`` is redundant, but required to work around a bug present in gcc 6.x.
return this->statementEqual(_lhsStmt, _rhsStmt);
}, _lhs, _rhs);
}
bool SyntacticallyEqual::expressionEqual(FunctionalInstruction const& _lhs, FunctionalInstruction const& _rhs)
{
return
_lhs.instruction == _rhs.instruction &&
containerEqual(_lhs.arguments, _rhs.arguments, [this](Expression const& _lhsExpr, Expression const& _rhsExpr) -> bool {
return (*this)(_lhsExpr, _rhsExpr);
});
}
bool SyntacticallyEqual::expressionEqual(FunctionCall const& _lhs, FunctionCall const& _rhs)
{
return
expressionEqual(_lhs.functionName, _rhs.functionName) &&
containerEqual(_lhs.arguments, _rhs.arguments, [this](Expression const& _lhsExpr, Expression const& _rhsExpr) -> bool {
return (*this)(_lhsExpr, _rhsExpr);
});
}
bool SyntacticallyEqual::expressionEqual(Identifier const& _lhs, Identifier const& _rhs)
{
auto lhsIt = m_identifiersLHS.find(_lhs.name);
auto rhsIt = m_identifiersRHS.find(_rhs.name);
return
(lhsIt == m_identifiersLHS.end() && rhsIt == m_identifiersRHS.end() && _lhs.name == _rhs.name) ||
(lhsIt != m_identifiersLHS.end() && rhsIt != m_identifiersRHS.end() && lhsIt->second == rhsIt->second);
}
bool SyntacticallyEqual::expressionEqual(Literal const& _lhs, Literal const& _rhs)
{
if (_lhs.kind != _rhs.kind || _lhs.type != _rhs.type)
return false;
if (_lhs.kind == LiteralKind::Number)
return valueOfNumberLiteral(_lhs) == valueOfNumberLiteral(_rhs);
else
return _lhs.value == _rhs.value;
}
bool SyntacticallyEqual::statementEqual(ExpressionStatement const& _lhs, ExpressionStatement const& _rhs)
{
return (*this)(_lhs.expression, _rhs.expression);
}
bool SyntacticallyEqual::statementEqual(Assignment const& _lhs, Assignment const& _rhs)
{
return containerEqual(
_lhs.variableNames,
_rhs.variableNames,
[this](Identifier const& _lhsVarName, Identifier const& _rhsVarName) -> bool {
return this->expressionEqual(_lhsVarName, _rhsVarName);
}
) && (*this)(*_lhs.value, *_rhs.value);
}
bool SyntacticallyEqual::statementEqual(VariableDeclaration const& _lhs, VariableDeclaration const& _rhs)
{
// first visit expression, then variable declarations
if (!compareUniquePtr<Expression, &SyntacticallyEqual::operator()>(_lhs.value, _rhs.value))
return false;
return containerEqual(_lhs.variables, _rhs.variables, [this](TypedName const& _lhsVarName, TypedName const& _rhsVarName) -> bool {
return this->visitDeclaration(_lhsVarName, _rhsVarName);
});
}
bool SyntacticallyEqual::statementEqual(FunctionDefinition const& _lhs, FunctionDefinition const& _rhs)
{
auto compare = [this](TypedName const& _lhsVarName, TypedName const& _rhsVarName) -> bool {
return this->visitDeclaration(_lhsVarName, _rhsVarName);
};
// first visit parameter declarations, then body
if (!containerEqual(_lhs.parameters, _rhs.parameters, compare))
return false;
if (!containerEqual(_lhs.returnVariables, _rhs.returnVariables, compare))
return false;
return statementEqual(_lhs.body, _rhs.body);
}
bool SyntacticallyEqual::statementEqual(If const& _lhs, If const& _rhs)
{
return
compareUniquePtr<Expression, &SyntacticallyEqual::operator()>(_lhs.condition, _rhs.condition) &&
statementEqual(_lhs.body, _rhs.body);
}
bool SyntacticallyEqual::statementEqual(Switch const& _lhs, Switch const& _rhs)
{
static auto const sortCasesByValue = [](Case const* _lhsCase, Case const* _rhsCase) -> bool {
return Less<Literal*>{}(_lhsCase->value.get(), _rhsCase->value.get());
};
std::set<Case const*, decltype(sortCasesByValue)> lhsCases(sortCasesByValue);
std::set<Case const*, decltype(sortCasesByValue)> rhsCases(sortCasesByValue);
for (auto const& lhsCase: _lhs.cases)
lhsCases.insert(&lhsCase);
for (auto const& rhsCase: _rhs.cases)
rhsCases.insert(&rhsCase);
return
compareUniquePtr<Expression, &SyntacticallyEqual::operator()>(_lhs.expression, _rhs.expression) &&
containerEqual(lhsCases, rhsCases, [this](Case const* _lhsCase, Case const* _rhsCase) -> bool {
return this->switchCaseEqual(*_lhsCase, *_rhsCase);
});
}
bool SyntacticallyEqual::switchCaseEqual(Case const& _lhs, Case const& _rhs)
{
return
compareUniquePtr<Literal, &SyntacticallyEqual::expressionEqual>(_lhs.value, _rhs.value) &&
statementEqual(_lhs.body, _rhs.body);
}
bool SyntacticallyEqual::statementEqual(ForLoop const& _lhs, ForLoop const& _rhs)
{
return
statementEqual(_lhs.pre, _rhs.pre) &&
compareUniquePtr<Expression, &SyntacticallyEqual::operator()>(_lhs.condition, _rhs.condition) &&
statementEqual(_lhs.body, _rhs.body) &&
statementEqual(_lhs.post, _rhs.post);
}
bool SyntacticallyEqual::statementEqual(Instruction const&, Instruction const&)
{
assertThrow(false, OptimizerException, "");
}
bool SyntacticallyEqual::statementEqual(Label const&, Label const&)
{
assertThrow(false, OptimizerException, "");
}
bool SyntacticallyEqual::statementEqual(StackAssignment const&, StackAssignment const&)
{
assertThrow(false, OptimizerException, "");
}
bool SyntacticallyEqual::statementEqual(Block const& _lhs, Block const& _rhs)
{
return containerEqual(_lhs.statements, _rhs.statements, [this](Statement const& _lhsStmt, Statement const& _rhsStmt) -> bool {
return (*this)(_lhsStmt, _rhsStmt);
});
}
bool SyntacticallyEqual::visitDeclaration(TypedName const& _lhs, TypedName const& _rhs)
{
if (_lhs.type != _rhs.type)
return false;
std::size_t id = m_idsUsed++;
m_identifiersLHS[_lhs.name] = id;
m_identifiersRHS[_rhs.name] = id;
return true;
}