solidity/libyul/AsmScope.h
2020-01-16 19:13:25 +01:00

94 lines
2.7 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/>.
*/
/**
* Scopes for identifiers.
*/
#pragma once
#include <liblangutil/Exceptions.h>
#include <libyul/YulString.h>
#include <libsolutil/Visitor.h>
#include <functional>
#include <memory>
#include <optional>
#include <variant>
namespace solidity::yul
{
struct Scope
{
using YulType = YulString;
struct Variable { YulType type; };
struct Function
{
std::vector<YulType> arguments;
std::vector<YulType> returns;
};
using Identifier = std::variant<Variable, Function>;
bool registerVariable(YulString _name, YulType const& _type);
bool registerFunction(
YulString _name,
std::vector<YulType> _arguments,
std::vector<YulType> _returns
);
/// Looks up the identifier in this or super scopes and returns a valid pointer if found
/// or a nullptr if not found. Variable lookups up across function boundaries will fail, as
/// will any lookups across assembly boundaries.
/// The pointer will be invalidated if the scope is modified.
/// @param _crossedFunction if true, we already crossed a function boundary during recursive lookup
Identifier* lookup(YulString _name);
/// Looks up the identifier in this and super scopes (will not find variables across function
/// boundaries and generally stops at assembly boundaries) and calls the visitor, returns
/// false if not found.
template <class V>
bool lookup(YulString _name, V const& _visitor)
{
if (Identifier* id = lookup(_name))
{
std::visit(_visitor, *id);
return true;
}
else
return false;
}
/// @returns true if the name exists in this scope or in super scopes (also searches
/// across function and assembly boundaries).
bool exists(YulString _name) const;
/// @returns the number of variables directly registered inside the scope.
size_t numberOfVariables() const;
/// @returns true if this scope is inside a function.
bool insideFunction() const;
Scope* superScope = nullptr;
/// If true, variables from the super scope are not visible here (other identifiers are),
/// but they are still taken into account to prevent shadowing.
bool functionScope = false;
std::map<YulString, Identifier> identifiers;
};
}