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/********************* */
/*! \file preprocessor.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Morgan Deters, Aina Niemetz
** 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 preprocessor of the SMT engine.
**/
#include "smt/preprocessor.h"
#include "options/smt_options.h"
#include "printer/printer.h"
#include "smt/abstract_values.h"
#include "smt/assertions.h"
#include "smt/dump.h"
#include "smt/smt_engine.h"
using namespace CVC4::theory;
using namespace CVC4::kind;
namespace CVC4 {
namespace smt {
Preprocessor::Preprocessor(SmtEngine& smt,
context::UserContext* u,
AbstractValues& abs)
: d_smt(smt),
d_absValues(abs),
d_propagator(true, true),
d_assertionsProcessed(u, false),
d_processor(smt, *smt.getResourceManager()),
d_rtf(u)
{
}
Preprocessor::~Preprocessor()
{
if (d_propagator.getNeedsFinish())
{
d_propagator.finish();
d_propagator.setNeedsFinish(false);
}
}
void Preprocessor::finishInit()
{
d_ppContext.reset(new preprocessing::PreprocessingPassContext(
&d_smt, &d_rtf, &d_propagator));
// initialize the preprocessing passes
d_processor.finishInit(d_ppContext.get());
}
bool Preprocessor::process(Assertions& as)
{
preprocessing::AssertionPipeline& ap = as.getAssertionPipeline();
// should not be called if empty
Assert(ap.size() != 0) << "Can only preprocess a non-empty list of assertions";
if (d_assertionsProcessed && options::incrementalSolving())
{
// TODO(b/1255): Substitutions in incremental mode should be managed with a
// proper data structure.
ap.enableStoreSubstsInAsserts();
}
else
{
ap.disableStoreSubstsInAsserts();
}
// process the assertions, return true if no conflict is discovered
return d_processor.apply(as);
}
void Preprocessor::postprocess(Assertions& as)
{
preprocessing::AssertionPipeline& ap = as.getAssertionPipeline();
// if incremental, compute which variables are assigned
if (options::incrementalSolving())
{
d_ppContext->recordSymbolsInAssertions(ap.ref());
}
// mark that we've processed assertions
d_assertionsProcessed = true;
}
void Preprocessor::clearLearnedLiterals()
{
d_propagator.getLearnedLiterals().clear();
}
void Preprocessor::cleanup() { d_processor.cleanup(); }
RemoveTermFormulas& Preprocessor::getTermFormulaRemover() { return d_rtf; }
Node Preprocessor::expandDefinitions(const Node& n, bool expandOnly)
{
std::unordered_map<Node, Node, NodeHashFunction> cache;
return expandDefinitions(n, cache, expandOnly);
}
Node Preprocessor::expandDefinitions(
const Node& node,
std::unordered_map<Node, Node, NodeHashFunction>& cache,
bool expandOnly)
{
Trace("smt") << "SMT expandDefinitions(" << node << ")" << endl;
// Substitute out any abstract values in node.
Node n = d_absValues.substituteAbstractValues(node);
if (options::typeChecking())
{
// Ensure node is type-checked at this point.
n.getType(true);
}
// expand only = true
return d_processor.expandDefinitions(n, cache, expandOnly);
}
Node Preprocessor::simplify(const Node& node, bool removeItes)
{
Trace("smt") << "SMT simplify(" << node << ")" << endl;
if (Dump.isOn("benchmark"))
{
d_smt.getOutputManager().getPrinter().toStreamCmdSimplify(
d_smt.getOutputManager().getDumpOut(), node);
}
Node nas = d_absValues.substituteAbstractValues(node);
if (options::typeChecking())
{
// ensure node is type-checked at this point
nas.getType(true);
}
std::unordered_map<Node, Node, NodeHashFunction> cache;
Node n = d_processor.expandDefinitions(nas, cache);
Node ns = applySubstitutions(n);
if (removeItes)
{
// also remove ites if asked
ns = d_rtf.replace(ns);
}
return ns;
}
Node Preprocessor::applySubstitutions(TNode node)
{
return Rewriter::rewrite(d_ppContext->getTopLevelSubstitutions().apply(node));
}
} // namespace smt
} // namespace CVC4
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