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/*
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 2015
* Gas consumption estimator working alongside the AST.
*/
#pragma once
#include <vector>
#include <map>
#include <array>
#include <libsolidity/ASTForward.h>
#include <libevmasm/GasMeter.h>
#include <libevmasm/Assembly.h>
namespace dev
{
namespace solidity
{
struct GasEstimator
{
public:
using GasConsumption = eth::GasMeter::GasConsumption;
using ASTGasConsumption = std::map<ASTNode const*, GasConsumption>;
using ASTGasConsumptionSelfAccumulated =
std::map<ASTNode const*, std::array<GasConsumption, 2>>;
/// Estimates the gas consumption for every assembly item in the given assembly and stores
/// it by source location.
/// @returns a mapping from each AST node to a pair of its particular and syntactically accumulated gas costs.
static ASTGasConsumptionSelfAccumulated structuralEstimation(
eth::AssemblyItems const& _items,
std::vector<ASTNode const*> const& _ast
);
/// @returns a mapping from nodes with non-overlapping source locations to gas consumptions such that
/// the following source locations are part of the mapping:
/// 1. source locations of statements that do not contain other statements
/// 2. maximal source locations that do not overlap locations coming from the first rule
static ASTGasConsumption breakToStatementLevel(
ASTGasConsumptionSelfAccumulated const& _gasCosts,
std::vector<ASTNode const*> const& _roots
);
/// @returns the estimated gas consumption by the (public or external) function with the
/// given signature. If no signature is given, estimates the maximum gas usage.
static GasConsumption functionalEstimation(
eth::AssemblyItems const& _items,
std::string const& _signature = ""
);
/// @returns the estimated gas consumption by the given function which starts at the given
/// offset into the list of assembly items.
/// @note this does not work correctly for recursive functions.
static GasConsumption functionalEstimation(
eth::AssemblyItems const& _items,
size_t const& _offset,
FunctionDefinition const& _function
);
private:
/// @returns the set of AST nodes which are the finest nodes at their location.
static std::set<ASTNode const*> finestNodesAtLocation(std::vector<ASTNode const*> const& _roots);
};
}
}