/*

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

/// Data structure representing a function call graph.

#pragma once

#include <libsolidity/ast/AST.h>

#include <map>

#include <set>

#include <variant>

namespace solidity::frontend

{

/**

* Function call graph for a contract at the granularity of Solidity functions and modifiers.

* The graph can represent the situation either at contract creation or after deployment.

* The graph does not preserve temporal relations between calls - edges coming out of the same node

* show which calls were performed but not in what order.

*

* Stores also extra information about contracts that can be created and events that can be emitted

* from any of the functions in it.

*/

struct CallGraph

{

enum class SpecialNode

{

InternalDispatch,

Entry,

};

using Node = std::variant<CallableDeclaration const*, SpecialNode>;

struct CompareByID

{

using is_transparent = void;

bool operator()(Node const& _lhs, Node const& _rhs) const;

bool operator()(Node const& _lhs, int64_t _rhs) const;

bool operator()(int64_t _lhs, Node const& _rhs) const;

};

/// Graph edges. Edges are directed and lead from the caller to the callee.

/// The map contains a key for every possible caller, even if does not actually perform

/// any calls.

std::map<Node, std::set<Node, CompareByID>, CompareByID> edges;

/// Contracts that need to be compiled before this one can be compiled.

/// The value is the ast node that created the dependency.

std::map<ContractDefinition const*, ASTNode const*, ASTCompareByID<ContractDefinition>> bytecodeDependency;

/// Events that may get emitted by functions present in the graph.

std::set<EventDefinition const*, ASTNode::CompareByID> emittedEvents;

/// Errors that are used by functions present in the graph.

std::set<ErrorDefinition const*, ASTNode::CompareByID> usedErrors;

};

}