solidity/libyul/optimiser/VarDeclInitializer.cpp
2020-01-07 15:51:50 +01:00

58 lines
1.8 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/>.
*/
#include <libyul/optimiser/VarDeclInitializer.h>
#include <libyul/AsmData.h>
#include <libsolutil/CommonData.h>
#include <libsolutil/Visitor.h>
using namespace std;
using namespace solidity;
using namespace solidity::yul;
void VarDeclInitializer::operator()(Block& _block)
{
ASTModifier::operator()(_block);
using OptionalStatements = std::optional<vector<Statement>>;
util::GenericVisitor visitor{
util::VisitorFallback<OptionalStatements>{},
[](VariableDeclaration& _varDecl) -> OptionalStatements
{
if (_varDecl.value)
return {};
Literal zero{{}, LiteralKind::Number, YulString{"0"}, {}};
if (_varDecl.variables.size() == 1)
{
_varDecl.value = make_unique<Expression>(std::move(zero));
return {};
}
else
{
OptionalStatements ret{vector<Statement>{}};
langutil::SourceLocation loc{std::move(_varDecl.location)};
for (auto& var: _varDecl.variables)
ret->emplace_back(VariableDeclaration{loc, {std::move(var)}, make_unique<Expression>(zero)});
return ret;
}
}
};
util::iterateReplacing(_block.statements, [&](auto&& _statement) { return std::visit(visitor, _statement); });
}