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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/********************* */
/** sat.h
** Original author: mdeters
** Major contributors: dejan
** Minor contributors (to current version): cconway
** This file is part of the CVC4 prototype.
** Copyright (c) 2009, 2010 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.
**
** SAT Solver.
**/
#include "cvc4_private.h"
#ifndef __CVC4__PROP__SAT_H
#define __CVC4__PROP__SAT_H
// Just defining this for now, since there's no other SAT solver bindings.
// Optional blocks below will be unconditionally included
#define __CVC4_USE_MINISAT
#include "util/options.h"
#ifdef __CVC4_USE_MINISAT
#include "prop/minisat/core/Solver.h"
#include "prop/minisat/core/SolverTypes.h"
#include "prop/minisat/simp/SimpSolver.h"
#endif /* __CVC4_USE_MINISAT */
namespace CVC4 {
class TheoryEngine;
namespace prop {
class PropEngine;
class CnfStream;
/* Definitions of abstract types and conversion functions for SAT interface */
#ifdef __CVC4_USE_MINISAT
/** Type of the SAT variables */
typedef minisat::Var SatVariable;
/** Type of the Sat literals */
typedef minisat::Lit SatLiteral;
/** Type of the SAT clauses */
typedef minisat::vec<SatLiteral> SatClause;
/**
* Returns the variable of the literal.
* @param lit the literal
*/
inline SatVariable literalToVariable(SatLiteral lit) {
return minisat::var(lit);
}
inline bool literalSign(SatLiteral lit) {
return minisat::sign(lit);
}
static inline size_t
hashSatLiteral(const SatLiteral& literal) {
return (size_t) minisat::toInt(literal);
}
#endif /* __CVC4_USE_MINISAT */
/**
* The proxy class that allows us to modify the internals of the SAT solver.
* It's only accessible from the PropEngine, and should be treated with major
* care.
*/
class SatSolver {
/** The prop engine we are using */
PropEngine* d_propEngine;
/** The CNF engine we are using */
CnfStream* d_cnfStream;
/** The theory engine we are using */
TheoryEngine* d_theoryEngine;
/** Context we will be using to synchronzie the sat solver */
context::Context* d_context;
/** Remember the options */
Options* d_options;
/* Pointer to the concrete SAT solver. Including this via the
preprocessor saves us a level of indirection vs, e.g., defining a
sub-class for each solver. */
#ifdef __CVC4_USE_MINISAT
/** Minisat solver */
minisat::SimpSolver* d_minisat;
#endif /* __CVC4_USE_MINISAT */
protected:
public:
/** Hash function for literals */
struct SatLiteralHashFunction {
inline size_t operator()(const SatLiteral& literal) const;
};
SatSolver(PropEngine* propEngine,
TheoryEngine* theoryEngine,
context::Context* context,
const Options* options);
~SatSolver();
bool solve();
void addClause(SatClause& clause);
SatVariable newVar(bool theoryAtom = false);
void theoryCheck(SatClause& conflict);
void enqueueTheoryLiteral(const SatLiteral& l);
void setCnfStream(CnfStream* cnfStream);
};
/* Functions that delegate to the concrete SAT solver. */
#ifdef __CVC4_USE_MINISAT
inline SatSolver::SatSolver(PropEngine* propEngine, TheoryEngine* theoryEngine,
context::Context* context, const Options* options) :
d_propEngine(propEngine),
d_cnfStream(NULL),
d_theoryEngine(theoryEngine),
d_context(context)
{
// Create the solver
d_minisat = new minisat::SimpSolver(this, d_context);
// Setup the verbosity
d_minisat->verbosity = (options->verbosity > 0) ? 1 : -1;
// Do not delete the satisfied clauses, just the learnt ones
d_minisat->remove_satisfied = false;
// Make minisat reuse the literal values
d_minisat->polarity_mode = minisat::SimpSolver::polarity_user;
}
inline SatSolver::~SatSolver() {
delete d_minisat;
}
inline bool SatSolver::solve() {
return d_minisat->solve();
}
inline void SatSolver::addClause(SatClause& clause) {
d_minisat->addClause(clause);
}
inline SatVariable SatSolver::newVar(bool theoryAtom) {
return d_minisat->newVar(true, true, theoryAtom);
}
#endif /* __CVC4_USE_MINISAT */
inline size_t
SatSolver::SatLiteralHashFunction::operator()(const SatLiteral& literal) const {
return hashSatLiteral(literal);
}
inline std::ostream& operator <<(std::ostream& out, SatLiteral lit) {
const char * s = (literalSign(lit)) ? "~" : " ";
out << s << literalToVariable(lit);
return out;
}
inline std::ostream& operator <<(std::ostream& out, const SatClause& clause) {
out << "clause:";
for(int i = 0; i < clause.size(); ++i) {
out << " " << clause[i];
}
out << ";";
return out;
}
}/* CVC4::prop namespace */
}/* CVC4 namespace */
#endif /* __CVC4__PROP__SAT_H */
|
