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/*
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 <libsolidity/ast/AST.h>
#include <libsolidity/analysis/ControlFlowGraph.h>
#include <libsolutil/Algorithms.h>
namespace solidity::frontend
{
/**
* Analyses all function flows and recursively removes all exit edges from CFG
* nodes that make function calls that will always revert.
*/
class ControlFlowRevertPruner
{
public:
ControlFlowRevertPruner(CFG& _cfg): m_cfg(_cfg) {}
void run();
private:
/// Possible revert states of a function call
enum class RevertState
{
AllPathsRevert,
HasNonRevertingPath,
Unknown,
};
/// Identify revert states of all function flows
void findRevertStates();
/// Modify function flows so that edges with reverting function calls are removed
void modifyFunctionFlows();
/// Control Flow Graph object.
CFG& m_cfg;
/// function/contract pairs mapped to their according revert state
std::map<CFG::FunctionContractTuple, RevertState> m_functions;
std::map<
std::tuple<FunctionCall const*, ContractDefinition const*>,
FunctionDefinition const*
> m_resolveCache;
};
}