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/********************* */
/*! \file decision_engine.h
** \verbatim
** Top contributors (to current version):
** Kshitij Bansal, Morgan Deters, Mathias Preiner
** This file is part of the CVC4 project.
** Copyright (c) 2009-2020 by the authors listed in the file AUTHORS
** in the top-level source directory and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
**
** \brief Decision engine
**
** Decision engine
**/
#include "cvc4_private.h"
#ifndef CVC4__DECISION__DECISION_ENGINE_H
#define CVC4__DECISION__DECISION_ENGINE_H
#include <vector>
#include "base/output.h"
#include "decision/decision_strategy.h"
#include "expr/node.h"
#include "prop/cnf_stream.h"
#include "prop/prop_engine.h"
#include "prop/sat_solver_types.h"
#include "smt/smt_engine_scope.h"
#include "smt/term_formula_removal.h"
using namespace std;
using namespace CVC4::prop;
using namespace CVC4::decision;
namespace CVC4 {
class DecisionEngine {
// PropEngine* d_propEngine;
CnfStream* d_cnfStream;
CDCLTSatSolverInterface* d_satSolver;
context::Context* d_satContext;
context::UserContext* d_userContext;
// Does decision engine know the answer?
context::CDO<SatValue> d_result;
// Disable creating decision engine without required parameters
DecisionEngine();
// init/shutdown state
unsigned d_engineState; // 0=pre-init; 1=init,pre-shutdown; 2=shutdown
/** Pointer to resource manager for associated SmtEngine */
ResourceManager* d_resourceManager;
public:
// Necessary functions
/** Constructor */
DecisionEngine(context::Context* sc,
context::UserContext* uc,
ResourceManager* rm);
/** Destructor, currently does nothing */
~DecisionEngine() {
Trace("decision") << "Destroying decision engine" << std::endl;
}
void setSatSolver(CDCLTSatSolverInterface* ss)
{
// setPropEngine should not be called more than once
Assert(d_satSolver == NULL);
Assert(ss != NULL);
d_satSolver = ss;
}
void setCnfStream(CnfStream* cs) {
// setPropEngine should not be called more than once
Assert(d_cnfStream == NULL);
Assert(cs != NULL);
d_cnfStream = cs;
}
/* Enables decision strategy based on options. */
void init();
/**
* This is called by SmtEngine, at shutdown time, just before
* destruction. It is important because there are destruction
* ordering issues between some parts of the system.
*/
void shutdown();
// Interface for External World to use our services
/** Gets the next decision based on strategies that are enabled */
SatLiteral getNext(bool& stopSearch);
/** Is the DecisionEngine in a state where it has solved everything? */
bool isDone() {
Trace("decision") << "DecisionEngine::isDone() returning "
<< (d_result != SAT_VALUE_UNKNOWN)
<< (d_result != SAT_VALUE_UNKNOWN ? "true" : "false")
<< std::endl;
return (d_result != SAT_VALUE_UNKNOWN);
}
/** */
Result getResult() {
switch(d_result.get()) {
case SAT_VALUE_TRUE: return Result(Result::SAT);
case SAT_VALUE_FALSE: return Result(Result::UNSAT);
case SAT_VALUE_UNKNOWN: return Result(Result::SAT_UNKNOWN, Result::UNKNOWN_REASON);
default: Assert(false) << "d_result is garbage";
}
return Result();
}
/** */
void setResult(SatValue val) {
d_result = val;
}
// External World helping us help the Strategies
/**
* Notify this class that assertion is an (input) assertion, not corresponding
* to a skolem definition.
*/
void addAssertion(TNode assertion);
/**
* Notify this class that lem is the skolem definition for skolem, which is
* a part of the current assertions.
*/
void addSkolemDefinition(TNode lem, TNode skolem);
// Interface for Strategies to use stuff stored in Decision Engine
// (which was possibly requested by them on initialization)
// Interface for Strategies to get information about External World
bool hasSatLiteral(TNode n) {
return d_cnfStream->hasLiteral(n);
}
SatLiteral getSatLiteral(TNode n) {
return d_cnfStream->getLiteral(n);
}
SatValue getSatValue(SatLiteral l) {
return d_satSolver->value(l);
}
SatValue getSatValue(TNode n) {
return getSatValue(getSatLiteral(n));
}
Node getNode(SatLiteral l) {
return d_cnfStream->getNode(l);
}
private:
/** The ITE decision strategy we have allocated */
std::unique_ptr<ITEDecisionStrategy> d_enabledITEStrategy;
};/* DecisionEngine class */
}/* CVC4 namespace */
#endif /* CVC4__DECISION__DECISION_ENGINE_H */
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