solidity/libyul/optimiser/NameDispenser.cpp
2018-11-23 14:29:00 +01:00

62 lines
1.6 KiB
C++

/*
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/>.
*/
/**
* Optimiser component that can create new unique names.
*/
#include <libyul/optimiser/NameDispenser.h>
#include <libyul/optimiser/NameCollector.h>
#include <libyul/AsmData.h>
using namespace std;
using namespace dev;
using namespace yul;
NameDispenser::NameDispenser(Block const& _ast):
NameDispenser(NameCollector(_ast).names())
{
}
NameDispenser::NameDispenser(set<YulString> _usedNames):
m_usedNames(std::move(_usedNames))
{
}
YulString NameDispenser::newName(YulString _nameHint, YulString _context)
{
// Shortening rules: Use a suffix of _prefix and a prefix of _context.
YulString prefix = _nameHint;
if (!_context.empty())
prefix = YulString{_context.str().substr(0, 10) + "_" + prefix.str()};
return newNameInternal(prefix);
}
YulString NameDispenser::newNameInternal(YulString _nameHint)
{
YulString name = _nameHint;
while (name.empty() || m_usedNames.count(name))
{
m_counter++;
name = YulString(_nameHint.str() + "_" + to_string(m_counter));
}
m_usedNames.emplace(name);
return name;
}