/*

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

#include <libsolidity/ast/AST.h>

#include <libsolidity/ast/ASTUtils.h>

#include <libsolutil/Algorithms.h>

namespace solidity::frontend

{

bool isConstantVariableRecursive(VariableDeclaration const& _varDecl)

{

solAssert(_varDecl.isConstant(), "Constant variable expected");

auto visitor = [](VariableDeclaration const& _variable, util::CycleDetector<VariableDeclaration>& _cycleDetector, size_t _depth)

{

solAssert(_depth < 256, "Recursion depth limit reached");

if (!_variable.value())

// This should result in an error later on.

return;

if (auto referencedVarDecl = dynamic_cast<VariableDeclaration const*>(

ASTNode::referencedDeclaration(*_variable.value()))

)

if (referencedVarDecl->isConstant())

_cycleDetector.run(*referencedVarDecl);

};

return util::CycleDetector<VariableDeclaration>(visitor).run(_varDecl) != nullptr;

}

VariableDeclaration const* rootConstVariableDeclaration(VariableDeclaration const& _varDecl)

{

solAssert(_varDecl.isConstant(), "Constant variable expected");

solAssert(!isConstantVariableRecursive(_varDecl), "Recursive declaration");

VariableDeclaration const* rootDecl = &_varDecl;

Identifier const* identifier;

while ((identifier = dynamic_cast<Identifier const*>(rootDecl->value().get())))

{

auto referencedVarDecl = dynamic_cast<VariableDeclaration const*>(identifier->annotation().referencedDeclaration);

if (!referencedVarDecl || !referencedVarDecl->isConstant())

return nullptr;

rootDecl = referencedVarDecl;

}

return rootDecl;

}

}