solidity/libyul/optimiser/OptimiserStep.h
2020-12-04 17:21:19 +01:00

92 lines
2.4 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/>.
*/
// SPDX-License-Identifier: GPL-3.0
#pragma once
#include <libyul/Exceptions.h>
#include <optional>
#include <string>
#include <set>
namespace solidity::yul
{
struct Dialect;
struct Block;
class YulString;
class NameDispenser;
struct OptimiserStepContext
{
Dialect const& dialect;
NameDispenser& dispenser;
std::set<YulString> const& reservedIdentifiers;
};
/**
* Construction to create dynamically callable objects out of the
* statically callable optimiser steps.
*/
struct OptimiserStep
{
explicit OptimiserStep(std::string _name): name(std::move(_name)) {}
virtual ~OptimiserStep() = default;
virtual void run(OptimiserStepContext&, Block&) const = 0;
/// @returns non-nullopt if the step cannot be run, for example because it requires
/// an SMT solver to be loaded, but none is available. In that case, the string
/// contains a human-readable reason.
virtual std::optional<std::string> invalidInCurrentEnvironment() const = 0;
std::string name;
};
template <class Step>
struct OptimiserStepInstance: public OptimiserStep
{
private:
template<typename T>
struct HasInvalidInCurrentEnvironmentMethod
{
private:
template<typename U> static auto test(int) -> decltype(U::invalidInCurrentEnvironment(), std::true_type());
template<typename> static std::false_type test(...);
public:
static constexpr bool value = decltype(test<T>(0))::value;
};
public:
OptimiserStepInstance(): OptimiserStep{Step::name} {}
void run(OptimiserStepContext& _context, Block& _ast) const override
{
Step::run(_context, _ast);
}
std::optional<std::string> invalidInCurrentEnvironment() const override
{
if constexpr (HasInvalidInCurrentEnvironmentMethod<Step>::value)
return Step::invalidInCurrentEnvironment();
else
return std::nullopt;
}
};
}