/*
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 <libsolidity/interface/Exceptions.h>
#include <boost/variant.hpp>
#include <functional>
#include <memory>
namespace dev
{
namespace solidity
{
namespace assembly
{
template <class...>
struct GenericVisitor{};
template <class Visitable, class... Others>
struct GenericVisitor<Visitable, Others...>: public GenericVisitor<Others...>
{
using GenericVisitor<Others...>::operator ();
explicit GenericVisitor(
std::function<void(Visitable&)> _visitor,
std::function<void(Others&)>... _otherVisitors
):
GenericVisitor<Others...>(_otherVisitors...),
m_visitor(_visitor)
{}
void operator()(Visitable& _v) const { m_visitor(_v); }
std::function<void(Visitable&)> m_visitor;
};
template <>
struct GenericVisitor<>: public boost::static_visitor<> {
void operator()() const {}
};
struct Scope
{
struct Variable
{
/// Used during code generation to store the stack height. @todo move there.
int stackHeight = 0;
/// Used during analysis to check whether we already passed the declaration inside the block.
/// @todo move there.
bool active = false;
};
struct Label
{
size_t id = unassignedLabelId;
static const size_t errorLabelId = -1;
static const size_t unassignedLabelId = 0;
};
struct Function
{
Function(size_t _arguments, size_t _returns): arguments(_arguments), returns(_returns) {}
size_t arguments = 0;
size_t returns = 0;
};
using Identifier = boost::variant<Variable, Label, Function>;
using Visitor = GenericVisitor<Variable const, Label const, Function const>;
using NonconstVisitor = GenericVisitor<Variable, Label, Function>;
bool registerVariable(std::string const& _name);
bool registerLabel(std::string const& _name);
bool registerFunction(std::string const& _name, size_t _arguments, size_t _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(std::string const& _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(std::string const& _name, V const& _visitor)
{
if (Identifier* id = lookup(_name))
{
boost::apply_visitor(_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(std::string const& _name);
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<std::string, Identifier> identifiers;
};
}
}
}
