solidity/libsolidity/formal/SymbolicVariables.h
2021-03-23 11:47:19 +01:00

302 lines
8.0 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/>.
*/
// SPDX-License-Identifier: GPL-3.0
#pragma once
#include <libsolidity/formal/SSAVariable.h>
#include <libsolidity/ast/Types.h>
#include <libsolidity/ast/TypeProvider.h>
#include <libsmtutil/SolverInterface.h>
#include <map>
#include <memory>
namespace solidity::frontend::smt
{
class EncodingContext;
class Type;
/**
* This abstract class represents the symbolic version of a program variable.
*/
class SymbolicVariable
{
public:
SymbolicVariable(
frontend::Type const* _type,
frontend::Type const* _originalType,
std::string _uniqueName,
EncodingContext& _context
);
SymbolicVariable(
smtutil::SortPointer _sort,
std::string _uniqueName,
EncodingContext& _context
);
SymbolicVariable(SymbolicVariable&&) = default;
virtual ~SymbolicVariable() = default;
virtual smtutil::Expression currentValue(frontend::Type const* _targetType = nullptr) const;
std::string currentName() const;
virtual smtutil::Expression valueAtIndex(unsigned _index) const;
virtual std::string nameAtIndex(unsigned _index) const;
virtual smtutil::Expression resetIndex();
virtual smtutil::Expression setIndex(unsigned _index);
virtual smtutil::Expression increaseIndex();
virtual smtutil::Expression operator()(std::vector<smtutil::Expression> /*_arguments*/) const
{
solAssert(false, "Function application to non-function.");
}
unsigned index() const { return m_ssa->index(); }
unsigned& index() { return m_ssa->index(); }
smtutil::SortPointer const& sort() const { return m_sort; }
frontend::Type const* type() const { return m_type; }
frontend::Type const* originalType() const { return m_originalType; }
protected:
std::string uniqueSymbol(unsigned _index) const;
/// SMT sort.
smtutil::SortPointer m_sort;
/// Solidity type, used for size and range in number types.
frontend::Type const* m_type;
/// Solidity original type, used for type conversion if necessary.
frontend::Type const* m_originalType;
std::string m_uniqueName;
EncodingContext& m_context;
std::unique_ptr<SSAVariable> m_ssa;
};
/**
* Specialization of SymbolicVariable for Bool
*/
class SymbolicBoolVariable: public SymbolicVariable
{
public:
SymbolicBoolVariable(
frontend::Type const* _type,
std::string _uniqueName,
EncodingContext& _context
);
};
/**
* Specialization of SymbolicVariable for Integers
*/
class SymbolicIntVariable: public SymbolicVariable
{
public:
SymbolicIntVariable(
frontend::Type const* _type,
frontend::Type const* _originalType,
std::string _uniqueName,
EncodingContext& _context
);
};
/**
* Specialization of SymbolicVariable for Address
*/
class SymbolicAddressVariable: public SymbolicIntVariable
{
public:
SymbolicAddressVariable(
std::string _uniqueName,
EncodingContext& _context
);
};
/**
* Specialization of SymbolicVariable for FixedBytes
*/
class SymbolicFixedBytesVariable: public SymbolicIntVariable
{
public:
SymbolicFixedBytesVariable(
frontend::Type const* _originalType,
unsigned _numBytes,
std::string _uniqueName,
EncodingContext& _context
);
};
/**
* Specialization of SymbolicVariable for FunctionType.
* Besides containing a symbolic function declaration,
* it also has an integer used as abstraction.
* By default, the abstract representation is used when
* values are requested, and the function declaration is
* used when operator() is applied over arguments.
*/
class SymbolicFunctionVariable: public SymbolicVariable
{
public:
SymbolicFunctionVariable(
frontend::Type const* _type,
std::string _uniqueName,
EncodingContext& _context
);
SymbolicFunctionVariable(
smtutil::SortPointer _sort,
std::string _uniqueName,
EncodingContext& _context
);
smtutil::Expression currentValue(frontend::Type const* _targetType = nullptr) const override;
// Explicit request the function declaration.
smtutil::Expression currentFunctionValue() const;
smtutil::Expression valueAtIndex(unsigned _index) const override;
// Explicit request the function declaration.
smtutil::Expression functionValueAtIndex(unsigned _index) const;
smtutil::Expression resetIndex() override;
smtutil::Expression setIndex(unsigned _index) override;
smtutil::Expression increaseIndex() override;
smtutil::Expression operator()(std::vector<smtutil::Expression> _arguments) const override;
private:
/// Creates a new function declaration.
void resetDeclaration();
/// Stores the current function declaration.
smtutil::Expression m_declaration;
/// Abstract representation.
SymbolicIntVariable m_abstract{
TypeProvider::uint256(),
TypeProvider::uint256(),
m_uniqueName + "_abstract",
m_context
};
};
/**
* Specialization of SymbolicVariable for Enum
*/
class SymbolicEnumVariable: public SymbolicVariable
{
public:
SymbolicEnumVariable(
frontend::Type const* _type,
std::string _uniqueName,
EncodingContext& _context
);
};
/**
* Specialization of SymbolicVariable for Tuple
*/
class SymbolicTupleVariable: public SymbolicVariable
{
public:
SymbolicTupleVariable(
frontend::Type const* _type,
std::string _uniqueName,
EncodingContext& _context
);
SymbolicTupleVariable(
smtutil::SortPointer _sort,
std::string _uniqueName,
EncodingContext& _context
);
smtutil::Expression currentValue(frontend::Type const* _targetType = nullptr) const override;
std::vector<smtutil::SortPointer> const& components() const;
smtutil::Expression component(
size_t _index,
frontend::Type const* _fromType = nullptr,
frontend::Type const* _toType = nullptr
) const;
};
/**
* Specialization of SymbolicVariable for Array
*/
class SymbolicArrayVariable: public SymbolicVariable
{
public:
SymbolicArrayVariable(
frontend::Type const* _type,
frontend::Type const* _originalTtype,
std::string _uniqueName,
EncodingContext& _context
);
SymbolicArrayVariable(
smtutil::SortPointer _sort,
std::string _uniqueName,
EncodingContext& _context
);
SymbolicArrayVariable(SymbolicArrayVariable&&) = default;
smtutil::Expression currentValue(frontend::Type const* _targetType = nullptr) const override;
smtutil::Expression valueAtIndex(unsigned _index) const override;
smtutil::Expression resetIndex() override { SymbolicVariable::resetIndex(); return m_pair.resetIndex(); }
smtutil::Expression setIndex(unsigned _index) override { SymbolicVariable::setIndex(_index); return m_pair.setIndex(_index); }
smtutil::Expression increaseIndex() override { SymbolicVariable::increaseIndex(); return m_pair.increaseIndex(); }
smtutil::Expression elements() const;
smtutil::Expression length() const;
smtutil::SortPointer tupleSort() { return m_pair.sort(); }
private:
SymbolicTupleVariable m_pair;
};
/**
* Specialization of SymbolicVariable for Struct.
*/
class SymbolicStructVariable: public SymbolicVariable
{
public:
SymbolicStructVariable(
frontend::Type const* _type,
std::string _uniqueName,
EncodingContext& _context
);
/// @returns the symbolic expression representing _member.
smtutil::Expression member(std::string const& _member) const;
/// @returns the symbolic expression representing this struct
/// with field _member updated.
smtutil::Expression assignMember(std::string const& _member, smtutil::Expression const& _memberValue);
/// @returns the symbolic expression representing this struct
/// with all fields updated with the given values.
smtutil::Expression assignAllMembers(std::vector<smtutil::Expression> const& _memberValues);
private:
std::map<std::string, unsigned> m_memberIndices;
};
}