solidity/libsolutil/Common.h
2021-04-16 10:56:56 +02:00

159 lines
4.5 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
/** @file Common.h
* @author Gav Wood <i@gavwood.com>
* @date 2014
*
* Very common stuff (i.e. that every other header needs except vector_ref.h).
*/
#pragma once
// way too many unsigned to size_t warnings in 32 bit build
#ifdef _M_IX86
#pragma warning(disable:4244)
#endif
#if _MSC_VER && _MSC_VER < 1900
#define _ALLOW_KEYWORD_MACROS
#define noexcept throw()
#endif
#ifdef __INTEL_COMPILER
#pragma warning(disable:3682) //call through incomplete class
#endif
#include <libsolutil/vector_ref.h>
#include <boost/version.hpp>
#if (BOOST_VERSION < 106500)
#error "Unsupported Boost version. At least 1.65 required."
#endif
#include <boost/multiprecision/cpp_int.hpp>
#include <map>
#include <utility>
#include <vector>
#include <functional>
#include <string>
namespace solidity
{
// Binary data types.
using bytes = std::vector<uint8_t>;
using bytesRef = util::vector_ref<uint8_t>;
using bytesConstRef = util::vector_ref<uint8_t const>;
// Numeric types.
using bigint = boost::multiprecision::number<boost::multiprecision::cpp_int_backend<>>;
using u256 = boost::multiprecision::number<boost::multiprecision::cpp_int_backend<256, 256, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>;
using s256 = boost::multiprecision::number<boost::multiprecision::cpp_int_backend<256, 256, boost::multiprecision::signed_magnitude, boost::multiprecision::unchecked, void>>;
using u160 = boost::multiprecision::number<boost::multiprecision::cpp_int_backend<160, 160, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>;
// Map types.
using StringMap = std::map<std::string, std::string>;
// String types.
using strings = std::vector<std::string>;
/// Interprets @a _u as a two's complement signed number and returns the resulting s256.
inline s256 u2s(u256 _u)
{
static bigint const c_end = bigint(1) << 256;
if (boost::multiprecision::bit_test(_u, 255))
return s256(-(c_end - _u));
else
return s256(_u);
}
/// @returns the two's complement signed representation of the signed number _u.
inline u256 s2u(s256 _u)
{
static bigint const c_end = bigint(1) << 256;
if (_u >= 0)
return u256(_u);
else
return u256(c_end + _u);
}
inline u256 exp256(u256 _base, u256 _exponent)
{
using boost::multiprecision::limb_type;
u256 result = 1;
while (_exponent)
{
if (boost::multiprecision::bit_test(_exponent, 0))
result *= _base;
_base *= _base;
_exponent >>= 1;
}
return result;
}
/// Checks whether _mantissa * (X ** _exp) fits into 4096 bits,
/// where X is given indirectly via _log2OfBase = log2(X).
bool fitsPrecisionBaseX(bigint const& _mantissa, double _log2OfBase, uint32_t _exp);
inline std::ostream& operator<<(std::ostream& os, bytes const& _bytes)
{
std::ostringstream ss;
ss << std::hex;
std::copy(_bytes.begin(), _bytes.end(), std::ostream_iterator<int>(ss, ","));
std::string result = ss.str();
result.pop_back();
os << "[" + result + "]";
return os;
}
/// RAII utility class whose destructor calls a given function.
class ScopeGuard
{
public:
explicit ScopeGuard(std::function<void(void)> _f): m_f(std::move(_f)) {}
~ScopeGuard() { m_f(); }
private:
std::function<void(void)> m_f;
};
/// RAII utility class that sets the value of a variable for the current scope and restores it to its old value
/// during its destructor.
template<typename V>
class ScopedSaveAndRestore
{
public:
explicit ScopedSaveAndRestore(V& _variable, V&& _value): m_variable(_variable), m_oldValue(std::move(_value))
{
std::swap(m_variable, m_oldValue);
}
ScopedSaveAndRestore(ScopedSaveAndRestore const&) = delete;
~ScopedSaveAndRestore() { std::swap(m_variable, m_oldValue); }
ScopedSaveAndRestore& operator=(ScopedSaveAndRestore const&) = delete;
private:
V& m_variable;
V m_oldValue;
};
template<typename V, typename... Args>
ScopedSaveAndRestore(V, Args...) -> ScopedSaveAndRestore<V>;
}