/********************* */
-/** output_channel.h
- ** Original author: mdeters
- ** Major contributors: none
- ** Minor contributors (to current version): none
- ** 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.
+/*! \file output_channel.h
+ ** \verbatim
+ ** Top contributors (to current version):
+ ** Morgan Deters, Andrew Reynolds, Tim King
+ ** 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 The theory output channel interface
**
** The theory output channel interface.
**/
#include "cvc4_private.h"
-#ifndef __CVC4__THEORY__OUTPUT_CHANNEL_H
-#define __CVC4__THEORY__OUTPUT_CHANNEL_H
+#ifndef CVC4__THEORY__OUTPUT_CHANNEL_H
+#define CVC4__THEORY__OUTPUT_CHANNEL_H
+
+#include <memory>
-#include "util/Assert.h"
+#include "expr/proof_node.h"
+#include "smt/logic_exception.h"
#include "theory/interrupted.h"
+#include "theory/trust_node.h"
+#include "util/resource_manager.h"
namespace CVC4 {
namespace theory {
+/** Properties of lemmas */
+enum class LemmaProperty : uint32_t
+{
+ // default
+ NONE = 0,
+ // whether the lemma is removable
+ REMOVABLE = 1,
+ // whether the processing of the lemma should send atoms to the caller
+ SEND_ATOMS = 2,
+ // whether the lemma is part of the justification for answering "sat"
+ NEEDS_JUSTIFY = 4
+};
+/** Define operator lhs | rhs */
+LemmaProperty operator|(LemmaProperty lhs, LemmaProperty rhs);
+/** Define operator lhs |= rhs */
+LemmaProperty& operator|=(LemmaProperty& lhs, LemmaProperty rhs);
+/** Define operator lhs & rhs */
+LemmaProperty operator&(LemmaProperty lhs, LemmaProperty rhs);
+/** Define operator lhs &= rhs */
+LemmaProperty& operator&=(LemmaProperty& lhs, LemmaProperty rhs);
+/** is the removable bit set on p? */
+bool isLemmaPropertyRemovable(LemmaProperty p);
+/** is the send atoms bit set on p? */
+bool isLemmaPropertySendAtoms(LemmaProperty p);
+/** is the needs justify bit set on p? */
+bool isLemmaPropertyNeedsJustify(LemmaProperty p);
+
/**
- * Generic "theory output channel" interface.
+ * Writes an lemma property name to a stream.
+ *
+ * @param out The stream to write to
+ * @param p The lemma property to write to the stream
+ * @return The stream
*/
-class OutputChannel {
- /** Disallow copying: private constructor */
- OutputChannel(const OutputChannel&);
-
- /** Disallow assignment: private operator=() */
- OutputChannel& operator=(const OutputChannel&);
+std::ostream& operator<<(std::ostream& out, LemmaProperty p);
-public:
+class Theory;
- /**
- * Construct an OutputChannel.
- */
- OutputChannel() {
- }
+/**
+ * Generic "theory output channel" interface.
+ *
+ * All methods can throw unrecoverable CVC4::Exception's unless otherwise
+ * documented.
+ */
+class OutputChannel {
+ public:
+ /** Construct an OutputChannel. */
+ OutputChannel() {}
/**
* Destructs an OutputChannel. This implementation does nothing,
* but we need a virtual destructor for safety in case subclasses
* have a destructor.
*/
- virtual ~OutputChannel() {
- }
+ virtual ~OutputChannel() {}
+
+ OutputChannel(const OutputChannel&) = delete;
+ OutputChannel& operator=(const OutputChannel&) = delete;
/**
* With safePoint(), the theory signals that it is at a safe point
* and can be interrupted.
+ *
+ * @throws Interrupted if the theory can be safely interrupted.
*/
- virtual void safePoint() throw(Interrupted, AssertionException) {
- }
+ virtual void safePoint(ResourceManager::Resource r) {}
/**
* Indicate a theory conflict has arisen.
* @param n - a conflict at the current decision level. This should
* be an AND-kinded node of literals that are TRUE in the current
* assignment and are in conflict (i.e., at least one must be
- * assigned false).
- *
- * @param safe - whether it is safe to be interrupted
+ * assigned false), or else a literal by itself (in the case of a
+ * unit conflict) which is assigned TRUE (and T-conflicting) in the
+ * current assignment.
*/
- virtual void conflict(TNode n, bool safe = false) throw(Interrupted, AssertionException) = 0;
+ virtual void conflict(TNode n) = 0;
/**
* Propagate a theory literal.
*
- * @param n - a theory consequence at the current decision level.
- *
- * @param safe - whether it is safe to be interrupted
+ * @param n - a theory consequence at the current decision level
+ * @return false if an immediate conflict was encountered
*/
- virtual void propagate(TNode n, bool safe = false) throw(Interrupted, AssertionException) = 0;
+ virtual bool propagate(TNode n) = 0;
/**
* Tell the core that a valid theory lemma at decision level 0 has
- * been detected. (This request a split.)
+ * been detected. (This requests a split.)
*
* @param n - a theory lemma valid at decision level 0
- * @param safe - whether it is safe to be interrupted
+ * @param p The properties of the lemma
*/
- virtual void lemma(TNode n, bool safe = false) throw(Interrupted, AssertionException) = 0;
+ virtual void lemma(TNode n, LemmaProperty p = LemmaProperty::NONE) = 0;
/**
- * Tell the core to add the following valid lemma as if it were a user assertion.
- * This should NOT be called during solving, only preprocessing.
+ * Request a split on a new theory atom. This is equivalent to
+ * calling lemma({OR n (NOT n)}).
*
- * @param n - a theory lemma valid to be asserted
- * @param safe - whether it is safe to be interrupted
+ * @param n - a theory atom; must be of Boolean type
*/
- virtual void augmentingLemma(TNode n, bool safe = false) throw(Interrupted, AssertionException) = 0;
+ void split(TNode n);
+
+ virtual void splitLemma(TNode n, bool removable = false) = 0;
/**
- * Provide an explanation in response to an explanation request.
+ * If a decision is made on n, it must be in the phase specified.
+ * Note that this is enforced *globally*, i.e., it is completely
+ * context-INdependent. If you ever requirePhase() on a literal,
+ * it is phase-locked forever and ever. If it is to ever have the
+ * other phase as its assignment, it will be because it has been
+ * propagated that way (or it's a unit, at decision level 0).
*
- * @param n - an explanation
- * @param safe - whether it is safe to be interrupted
+ * @param n - a theory atom with a SAT literal assigned; must have
+ * been pre-registered
+ * @param phase - the phase to decide on n
+ */
+ virtual void requirePhase(TNode n, bool phase) = 0;
+
+ /**
+ * Notification from a theory that it realizes it is incomplete at
+ * this context level. If SAT is later determined by the
+ * TheoryEngine, it should actually return an UNKNOWN result.
+ */
+ virtual void setIncomplete() = 0;
+
+ /**
+ * "Spend" a "resource." The meaning is specific to the context in
+ * which the theory is operating, and may even be ignored. The
+ * intended meaning is that if the user has set a limit on the "units
+ * of resource" that can be expended in a search, and that limit is
+ * exceeded, then the search is terminated. Note that the check for
+ * termination occurs in the main search loop, so while theories
+ * should call OutputChannel::spendResource() during particularly
+ * long-running operations, they cannot rely on resource() to break
+ * out of infinite or intractable computations.
+ */
+ virtual void spendResource(ResourceManager::Resource r) {}
+
+ /**
+ * Handle user attribute.
+ * Associates theory t with the attribute attr. Theory t will be
+ * notified whenever an attribute of name attr is set on a node.
+ * This can happen through, for example, the SMT-LIBv2 language.
+ */
+ virtual void handleUserAttribute(const char* attr, Theory* t) {}
+
+ /** Demands that the search restart from sat search level 0.
+ * Using this leads to non-termination issues.
+ * It is appropriate for prototyping for theories.
*/
- virtual void explanation(TNode n, bool safe = false) throw(Interrupted, AssertionException) = 0;
+ virtual void demandRestart() {}
-};/* class OutputChannel */
+ //---------------------------- new proof
+ /**
+ * Let pconf be the pair (Node conf, ProofGenerator * pfg). This method
+ * sends conf on the output channel of this class whose proof can be generated
+ * by the generator pfg. Apart from pfg, the interface for this method is
+ * the same as OutputChannel.
+ */
+ virtual void trustedConflict(TrustNode pconf);
+ /**
+ * Let plem be the pair (Node lem, ProofGenerator * pfg).
+ * Send lem on the output channel of this class whose proof can be generated
+ * by the generator pfg. Apart from pfg, the interface for this method is
+ * the same as OutputChannel.
+ */
+ virtual void trustedLemma(TrustNode lem,
+ LemmaProperty p = LemmaProperty::NONE);
+ //---------------------------- end new proof
+}; /* class OutputChannel */
-}/* CVC4::theory namespace */
-}/* CVC4 namespace */
+} // namespace theory
+} // namespace CVC4
-#endif /* __CVC4__THEORY__OUTPUT_CHANNEL_H */
+#endif /* CVC4__THEORY__OUTPUT_CHANNEL_H */