Head

GCC Code Coverage Report

Directory:	.		Exec	Total	Coverage
File:	src/proof/lazy_proof.cpp	Lines:	94	97	96.9 %
Date:	2021-08-03	Branches:	168	350	48.0 %


/******************************************************************************
 * Top contributors (to current version):
 *   Andrew Reynolds, Aina Niemetz
 *
 * This file is part of the cvc5 project.
 *
 * Copyright (c) 2009-2021 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.
 * ****************************************************************************
 *
 * Implementation of lazy proof utility.
 */

#include "proof/lazy_proof.h"

#include "proof/proof_ensure_closed.h"
#include "proof/proof_node.h"
#include "proof/proof_node_manager.h"

using namespace cvc5::kind;

namespace cvc5 {

LazyCDProof::LazyCDProof(ProofNodeManager* pnm,
                         ProofGenerator* dpg,
                         context::Context* c,
                         const std::string& name)
    : CDProof(pnm, c, name), d_gens(c ? c : &d_context), d_defaultGen(dpg)
{
}

LazyCDProof::~LazyCDProof() {}

std::shared_ptr<ProofNode> LazyCDProof::getProofFor(Node fact)
{
  Trace("lazy-cdproof") << "LazyCDProof::mkLazyProof " << fact << std::endl;
  // make the proof, which should always be non-null, since we construct an
  // assumption in the worst case.
  std::shared_ptr<ProofNode> opf = CDProof::getProofFor(fact);
  Assert(opf != nullptr);
  if (!hasGenerators())
  {
    Trace("lazy-cdproof") << "...no generators, finished" << std::endl;
    // optimization: no generators, we are done
    return opf;
  }
  // otherwise, we traverse the proof opf and fill in the ASSUME leafs that
  // have generators
  std::unordered_set<ProofNode*> visited;
  std::unordered_set<ProofNode*>::iterator it;
  std::vector<ProofNode*> visit;
  ProofNode* cur;
  visit.push_back(opf.get());
  do
  {
    cur = visit.back();
    visit.pop_back();
    it = visited.find(cur);

    if (it == visited.end())
    {
      visited.insert(cur);
      Node cfact = cur->getResult();
      if (getProof(cfact).get() != cur)
      {
        // We don't own this proof, skip it. This is to ensure that this method
        // is idempotent, since it may be the case that a previous call to
        // getProofFor connected a proof from a proof generator as a child of
        // a ProofNode in the range of the map in CDProof. Thus, this ensures
        // we don't touch such proofs.
        Trace("lazy-cdproof") << "...skip unowned proof" << std::endl;
      }
      else if (cur->getRule() == PfRule::ASSUME)
      {
        bool isSym = false;
        ProofGenerator* pg = getGeneratorFor(cfact, isSym);
        if (pg != nullptr)
        {
          Trace("lazy-cdproof")
              << "LazyCDProof: Call generator " << pg->identify()
              << " for assumption " << cfact << std::endl;
          Node cfactGen = isSym ? CDProof::getSymmFact(cfact) : cfact;
          Assert(!cfactGen.isNull());
          // Do not use the addProofTo interface, instead use the update node
          // interface, since this ensures that we don't take ownership for
          // the current proof. Instead, it is only linked, and ignored on
          // future calls to getProofFor due to the check above.
          std::shared_ptr<ProofNode> pgc = pg->getProofFor(cfactGen);
          // If the proof was null, then the update is not performed. This is
          // not considered an error, since this behavior is equivalent to
          // if pg had provided the proof (ASSUME cfactGen). Ensuring the
          // proper behavior wrt closed proofs should be done outside this
          // method.
          if (pgc != nullptr)
          {
            Trace("lazy-cdproof-gen")
                << "LazyCDProof: stored proof: " << *pgc.get() << std::endl;

            if (isSym)
            {
              d_manager->updateNode(cur, PfRule::SYMM, {pgc}, {});
            }
            else
            {
              d_manager->updateNode(cur, pgc.get());
            }
            Trace("lazy-cdproof") << "LazyCDProof: Successfully added fact for "
                                  << cfactGen << std::endl;
          }
        }
        else
        {
          Trace("lazy-cdproof") << "LazyCDProof: " << identify()
                                << " : No generator for " << cfact << std::endl;
        }
        // Notice that we do not traverse the proofs that have been generated
        // lazily by the proof generators here.  In other words, we assume that
        // the proofs from provided proof generators are final and need
        // no further modification by this class.
      }
      else
      {
        const std::vector<std::shared_ptr<ProofNode>>& cc = cur->getChildren();
        for (const std::shared_ptr<ProofNode>& cp : cc)
        {
          visit.push_back(cp.get());
        }
      }
    }
  } while (!visit.empty());
  // we have now updated the ASSUME leafs of opf, return it
  Trace("lazy-cdproof") << "...finished" << std::endl;
  Assert(opf->getResult() == fact);
  return opf;
}

void LazyCDProof::addLazyStep(Node expected,
                              ProofGenerator* pg,
                              PfRule idNull,
                              bool isClosed,
                              const char* ctx,
                              bool forceOverwrite)
{
  if (pg == nullptr)
  {
    // null generator, should have given a proof rule
    if (idNull == PfRule::ASSUME)
    {
      Unreachable() << "LazyCDProof::addLazyStep: " << identify()
                    << ": failed to provide proof generator for " << expected;
      return;
    }
    Trace("lazy-cdproof") << "LazyCDProof::addLazyStep: " << expected
                          << " set (trusted) step " << idNull << "\n";
    addStep(expected, idNull, {}, {expected});
    return;
  }
  Trace("lazy-cdproof") << "LazyCDProof::addLazyStep: " << expected
                        << " set to generator " << pg->identify() << "\n";
  if (!forceOverwrite)
  {
    NodeProofGeneratorMap::const_iterator it = d_gens.find(expected);
    if (it != d_gens.end())
    {
      // don't overwrite something that is already there
      return;
    }
  }
  // just store now
  d_gens.insert(expected, pg);
  // debug checking
  if (isClosed)
  {
    Trace("lazy-cdproof-debug") << "Checking closed..." << std::endl;
    pfgEnsureClosed(expected, pg, "lazy-cdproof-debug", ctx);
  }
}

ProofGenerator* LazyCDProof::getGeneratorFor(Node fact, bool& isSym)
{
  isSym = false;
  NodeProofGeneratorMap::const_iterator it = d_gens.find(fact);
  if (it != d_gens.end())
  {
    return (*it).second;
  }
  Node factSym = CDProof::getSymmFact(fact);
  // could be symmetry
  if (factSym.isNull())
  {
    // can't be symmetry, return the default generator
    return d_defaultGen;
  }
  it = d_gens.find(factSym);
  if (it != d_gens.end())
  {
    isSym = true;
    return (*it).second;
  }
  // return the default generator
  return d_defaultGen;
}

bool LazyCDProof::hasGenerators() const
{
  return !d_gens.empty() || d_defaultGen != nullptr;
}

bool LazyCDProof::hasGenerator(Node fact) const
{
  if (d_defaultGen != nullptr)
  {
    return true;
  }
  NodeProofGeneratorMap::const_iterator it = d_gens.find(fact);
  if (it != d_gens.end())
  {
    return true;
  }
  // maybe there is a symmetric fact?
  Node factSym = CDProof::getSymmFact(fact);
  if (!factSym.isNull())
  {
    it = d_gens.find(factSym);
  }
  return it != d_gens.end();
}

}  // namespace cvc5


Generated by: GCOVR (Version 3.2)

Line	Exec	Source
1		/******************************************************************************
2		* Top contributors (to current version):
3		* Andrew Reynolds, Aina Niemetz
4		*
5		* This file is part of the cvc5 project.
6		*
7		* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
8		* in the top-level source directory and their institutional affiliations.
9		* All rights reserved. See the file COPYING in the top-level source
10		* directory for licensing information.
11		* ****************************************************************************
12		*
13		* Implementation of lazy proof utility.
14		*/
15
16		#include "proof/lazy_proof.h"
17
18		#include "proof/proof_ensure_closed.h"
19		#include "proof/proof_node.h"
20		#include "proof/proof_node_manager.h"
21
22		using namespace cvc5::kind;
23
24		namespace cvc5 {
25
26	264778	LazyCDProof::LazyCDProof(ProofNodeManager* pnm,
27		ProofGenerator* dpg,
28		context::Context* c,
29	264778	const std::string& name)
30	264778	: CDProof(pnm, c, name), d_gens(c ? c : &d_context), d_defaultGen(dpg)
31		{
32	264778	}
33
34	319111	LazyCDProof::~LazyCDProof() {}
35
36	1580682	std::shared_ptr<ProofNode> LazyCDProof::getProofFor(Node fact)
37		{
38	1580682	Trace("lazy-cdproof") << "LazyCDProof::mkLazyProof " << fact << std::endl;
39		// make the proof, which should always be non-null, since we construct an
40		// assumption in the worst case.
41	1580682	std::shared_ptr<ProofNode> opf = CDProof::getProofFor(fact);
42	1580682	Assert(opf != nullptr);
43	1580682	if (!hasGenerators())
44		{
45	670254	Trace("lazy-cdproof") << "...no generators, finished" << std::endl;
46		// optimization: no generators, we are done
47	670254	return opf;
48		}
49		// otherwise, we traverse the proof opf and fill in the ASSUME leafs that
50		// have generators
51	1820856	std::unordered_set<ProofNode*> visited;
52	910428	std::unordered_set<ProofNode*>::iterator it;
53	1820856	std::vector<ProofNode*> visit;
54		ProofNode* cur;
55	910428	visit.push_back(opf.get());
56	54356756	do
57		{
58	55267184	cur = visit.back();
59	55267184	visit.pop_back();
60	55267184	it = visited.find(cur);
61
62	55267184	if (it == visited.end())
63		{
64	15698426	visited.insert(cur);
65	31396852	Node cfact = cur->getResult();
66	15698426	if (getProof(cfact).get() != cur)
67		{
68		// We don't own this proof, skip it. This is to ensure that this method
69		// is idempotent, since it may be the case that a previous call to
70		// getProofFor connected a proof from a proof generator as a child of
71		// a ProofNode in the range of the map in CDProof. Thus, this ensures
72		// we don't touch such proofs.
73	488785	Trace("lazy-cdproof") << "...skip unowned proof" << std::endl;
74		}
75	15209641	else if (cur->getRule() == PfRule::ASSUME)
76		{
77	963754	bool isSym = false;
78	963754	ProofGenerator* pg = getGeneratorFor(cfact, isSym);
79	963754	if (pg != nullptr)
80		{
81	1719792	Trace("lazy-cdproof")
82	1719792	<< "LazyCDProof: Call generator " << pg->identify()
83	859896	<< " for assumption " << cfact << std::endl;
84	1719792	Node cfactGen = isSym ? CDProof::getSymmFact(cfact) : cfact;
85	859896	Assert(!cfactGen.isNull());
86		// Do not use the addProofTo interface, instead use the update node
87		// interface, since this ensures that we don't take ownership for
88		// the current proof. Instead, it is only linked, and ignored on
89		// future calls to getProofFor due to the check above.
90	1719792	std::shared_ptr<ProofNode> pgc = pg->getProofFor(cfactGen);
91		// If the proof was null, then the update is not performed. This is
92		// not considered an error, since this behavior is equivalent to
93		// if pg had provided the proof (ASSUME cfactGen). Ensuring the
94		// proper behavior wrt closed proofs should be done outside this
95		// method.
96	859896	if (pgc != nullptr)
97		{
98	1719792	Trace("lazy-cdproof-gen")
99	859896	<< "LazyCDProof: stored proof: " << *pgc.get() << std::endl;
100
101	859896	if (isSym)
102		{
103	4410	d_manager->updateNode(cur, PfRule::SYMM, {pgc}, {});
104		}
105		else
106		{
107	855486	d_manager->updateNode(cur, pgc.get());
108		}
109	1719792	Trace("lazy-cdproof") << "LazyCDProof: Successfully added fact for "
110	859896	<< cfactGen << std::endl;
111		}
112		}
113		else
114		{
115	207716	Trace("lazy-cdproof") << "LazyCDProof: " << identify()
116	103858	<< " : No generator for " << cfact << std::endl;
117		}
118		// Notice that we do not traverse the proofs that have been generated
119		// lazily by the proof generators here. In other words, we assume that
120		// the proofs from provided proof generators are final and need
121		// no further modification by this class.
122		}
123		else
124		{
125	14245887	const std::vector<std::shared_ptr<ProofNode>>& cc = cur->getChildren();
126	68602643	for (const std::shared_ptr<ProofNode>& cp : cc)
127		{
128	54356756	visit.push_back(cp.get());
129		}
130		}
131		}
132	55267184	} while (!visit.empty());
133		// we have now updated the ASSUME leafs of opf, return it
134	910428	Trace("lazy-cdproof") << "...finished" << std::endl;
135	910428	Assert(opf->getResult() == fact);
136	910428	return opf;
137		}
138
139	1106790	void LazyCDProof::addLazyStep(Node expected,
140		ProofGenerator* pg,
141		PfRule idNull,
142		bool isClosed,
143		const char* ctx,
144		bool forceOverwrite)
145		{
146	1106790	if (pg == nullptr)
147		{
148		// null generator, should have given a proof rule
149	32291	if (idNull == PfRule::ASSUME)
150		{
151		Unreachable() << "LazyCDProof::addLazyStep: " << identify()
152		<< ": failed to provide proof generator for " << expected;
153		return;
154		}
155	64582	Trace("lazy-cdproof") << "LazyCDProof::addLazyStep: " << expected
156	32291	<< " set (trusted) step " << idNull << "\n";
157	32291	addStep(expected, idNull, {}, {expected});
158	32291	return;
159		}
160	2148998	Trace("lazy-cdproof") << "LazyCDProof::addLazyStep: " << expected
161	1074499	<< " set to generator " << pg->identify() << "\n";
162	1074499	if (!forceOverwrite)
163		{
164	1074499	NodeProofGeneratorMap::const_iterator it = d_gens.find(expected);
165	1074499	if (it != d_gens.end())
166		{
167		// don't overwrite something that is already there
168	441905	return;
169		}
170		}
171		// just store now
172	632594	d_gens.insert(expected, pg);
173		// debug checking
174	632594	if (isClosed)
175		{
176	163985	Trace("lazy-cdproof-debug") << "Checking closed..." << std::endl;
177	163985	pfgEnsureClosed(expected, pg, "lazy-cdproof-debug", ctx);
178		}
179		}
180
181	963754	ProofGenerator* LazyCDProof::getGeneratorFor(Node fact, bool& isSym)
182		{
183	963754	isSym = false;
184	963754	NodeProofGeneratorMap::const_iterator it = d_gens.find(fact);
185	963754	if (it != d_gens.end())
186		{
187	135640	return (*it).second;
188		}
189	1656228	Node factSym = CDProof::getSymmFact(fact);
190		// could be symmetry
191	828114	if (factSym.isNull())
192		{
193		// can't be symmetry, return the default generator
194	265680	return d_defaultGen;
195		}
196	562434	it = d_gens.find(factSym);
197	562434	if (it != d_gens.end())
198		{
199	4410	isSym = true;
200	4410	return (*it).second;
201		}
202		// return the default generator
203	558024	return d_defaultGen;
204		}
205
206	1580682	bool LazyCDProof::hasGenerators() const
207		{
208	1580682	return !d_gens.empty() \|\| d_defaultGen != nullptr;
209		}
210
211	385856	bool LazyCDProof::hasGenerator(Node fact) const
212		{
213	385856	if (d_defaultGen != nullptr)
214		{
215		return true;
216		}
217	385856	NodeProofGeneratorMap::const_iterator it = d_gens.find(fact);
218	385856	if (it != d_gens.end())
219		{
220	1511	return true;
221		}
222		// maybe there is a symmetric fact?
223	768690	Node factSym = CDProof::getSymmFact(fact);
224	384345	if (!factSym.isNull())
225		{
226	12429	it = d_gens.find(factSym);
227		}
228	384345	return it != d_gens.end();
229		}
230
231	29286	} // namespace cvc5