aboutsummaryrefslogtreecommitdiffstats
path: root/libsolidity/formal/SymbolicVariable.h
blob: 417e1f922fa3e654a662be8f4e00361b1c28c632 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
/*
    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/>.
*/

#pragma once

#include <libsolidity/formal/SSAVariable.h>

#include <libsolidity/formal/SolverInterface.h>

#include <libsolidity/ast/Types.h>

#include <memory>

namespace dev
{
namespace solidity
{

class Type;

/**
 * This class represents the symbolic version of a program variable.
 */
class SymbolicVariable
{
public:
    SymbolicVariable(
        Type const& _type,
        std::string const& _uniqueName,
        smt::SolverInterface& _interface
    );
    virtual ~SymbolicVariable() = default;

    smt::Expression currentValue() const
    {
        return valueAtIndex(m_ssa->index());
    }

    virtual smt::Expression valueAtIndex(int _index) const = 0;

    smt::Expression increaseIndex()
    {
        ++(*m_ssa);
        return currentValue();
    }

    int index() const { return m_ssa->index(); }
    int& index() { return m_ssa->index(); }

    /// Sets the var to the default value of its type.
    /// Inherited types must implement.
    virtual void setZeroValue() = 0;
    /// The unknown value is the full range of valid values.
    /// It is sub-type dependent, but not mandatory.
    virtual void setUnknownValue() {}

protected:
    std::string uniqueSymbol(int _index) const;

    Type const& m_type;
    std::string m_uniqueName;
    smt::SolverInterface& m_interface;
    std::shared_ptr<SSAVariable> m_ssa = nullptr;
};

}
}