path: root/libsolidity/analysis/PostTypeChecker.cpp

/*
    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/>.
*/

#include <libsolidity/analysis/PostTypeChecker.h>
#include <libsolidity/ast/AST.h>
#include <libsolidity/analysis/SemVerHandler.h>
#include <libsolidity/interface/ErrorReporter.h>
#include <libsolidity/interface/Version.h>

#include <boost/range/adaptor/map.hpp>

#include <memory>

using namespace std;
using namespace dev;
using namespace dev::solidity;


bool PostTypeChecker::check(ASTNode const& _astRoot)
{
    _astRoot.accept(*this);
    return Error::containsOnlyWarnings(m_errorReporter.errors());
}

bool PostTypeChecker::visit(ContractDefinition const&)
{
    solAssert(!m_currentConstVariable, "");
    solAssert(m_constVariableDependencies.empty(), "");
    return true;
}

void PostTypeChecker::endVisit(ContractDefinition const&)
{
    solAssert(!m_currentConstVariable, "");
    for (auto declaration: m_constVariables)
        if (auto identifier = findCycle(declaration))
            m_errorReporter.typeError(
                declaration->location(),
                "The value of the constant " + declaration->name() +
                " has a cyclic dependency via " + identifier->name() + "."
            );

    m_constVariables.clear();
    m_constVariableDependencies.clear();
}

bool PostTypeChecker::visit(VariableDeclaration const& _variable)
{
    solAssert(!m_currentConstVariable, "");
    if (_variable.isConstant())
    {
        m_currentConstVariable = &_variable;
        m_constVariables.push_back(&_variable);
    }
    return true;
}

void PostTypeChecker::endVisit(VariableDeclaration const& _variable)
{
    if (_variable.isConstant())
    {
        solAssert(m_currentConstVariable == &_variable, "");
        m_currentConstVariable = nullptr;
    }
}

bool PostTypeChecker::visit(Identifier const& _identifier)
{
    if (m_currentConstVariable)
        if (auto var = dynamic_cast<VariableDeclaration const*>(_identifier.annotation().referencedDeclaration))
            if (var->isConstant())
                m_constVariableDependencies[m_currentConstVariable].insert(var);
    return true;
}

VariableDeclaration const* PostTypeChecker::findCycle(
    VariableDeclaration const* _startingFrom,
    set<VariableDeclaration const*> const& _seen
)
{
    if (_seen.count(_startingFrom))
        return _startingFrom;
    else if (m_constVariableDependencies.count(_startingFrom))
    {
        set<VariableDeclaration const*> seen(_seen);
        seen.insert(_startingFrom);
        for (auto v: m_constVariableDependencies[_startingFrom])
            if (findCycle(v, seen))
                return v;
    }
    return nullptr;
}