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//-----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All Rights Reserved.
//
//-----------------------------------------------------------------------------
using System;
using System.Diagnostics.Contracts;
using System.Collections.Generic;
using Microsoft.Boogie;
using Microsoft.Boogie.VCExprAST;
using Microsoft.Basetypes;
using System.Collections;
using System.IO;
using System.Threading;
using VC;
namespace Microsoft.Boogie.Houdini {
public class ExistentialConstantCollector : StandardVisitor {
public static HashSet<Variable> CollectHoudiniConstants(Houdini houdini, Implementation impl) {
ExistentialConstantCollector collector = new ExistentialConstantCollector(houdini);
collector.VisitImplementation(impl);
return collector.houdiniConstants;
}
private ExistentialConstantCollector(Houdini houdini) {
this.houdini = houdini;
this.houdiniConstants = new HashSet<Variable>();
}
private Houdini houdini;
private HashSet<Variable> houdiniConstants;
public override Cmd VisitAssertRequiresCmd(AssertRequiresCmd node) {
AddHoudiniConstant(node);
return base.VisitAssertRequiresCmd(node);
}
public override Cmd VisitAssertEnsuresCmd(AssertEnsuresCmd node) {
AddHoudiniConstant(node);
return base.VisitAssertEnsuresCmd(node);
}
public override Cmd VisitAssertCmd(AssertCmd node) {
AddHoudiniConstant(node);
return base.VisitAssertCmd(node);
}
public override Cmd VisitAssumeCmd(AssumeCmd node) {
AddHoudiniConstant(node);
return base.VisitAssumeCmd(node);
}
private void AddHoudiniConstant(PredicateCmd node) {
Variable houdiniConstant;
if (houdini.MatchCandidate(node.Expr, out houdiniConstant))
houdiniConstants.Add(houdiniConstant);
}
}
public class HoudiniSession {
public static double proverTime = 0;
public static int numProverQueries = 0;
public static double unsatCoreProverTime = 0;
public static int numUnsatCoreProverQueries = 0;
public static int numUnsatCorePrunings = 0;
public string descriptiveName;
private VCExpr conjecture;
private ProverInterface.ErrorHandler handler;
ConditionGeneration.CounterexampleCollector collector;
HashSet<Variable> unsatCoreSet;
HashSet<Variable> houdiniConstants;
Houdini houdini;
Implementation implementation;
public bool InUnsatCore(Variable constant) {
if (unsatCoreSet == null)
return true;
if (unsatCoreSet.Contains(constant))
return true;
numUnsatCorePrunings++;
return false;
}
public HoudiniSession(Houdini houdini, VCGen vcgen, ProverInterface proverInterface, Program program, Implementation impl) {
descriptiveName = impl.Name;
collector = new ConditionGeneration.CounterexampleCollector();
collector.OnProgress("HdnVCGen", 0, 0, 0.0);
vcgen.ConvertCFG2DAG(impl);
ModelViewInfo mvInfo;
Hashtable/*TransferCmd->ReturnCmd*/ gotoCmdOrigins = vcgen.PassifyImpl(impl, out mvInfo);
houdiniConstants = ExistentialConstantCollector.CollectHoudiniConstants(houdini, impl);
var exprGen = proverInterface.Context.ExprGen;
VCExpr controlFlowVariableExpr = CommandLineOptions.Clo.UseLabels ? null : exprGen.Integer(BigNum.ZERO);
Hashtable/*<int, Absy!>*/ label2absy;
conjecture = vcgen.GenerateVC(impl, controlFlowVariableExpr, out label2absy, proverInterface.Context);
if (!CommandLineOptions.Clo.UseLabels) {
VCExpr controlFlowFunctionAppl = exprGen.ControlFlowFunctionApplication(exprGen.Integer(BigNum.ZERO), exprGen.Integer(BigNum.ZERO));
VCExpr eqExpr = exprGen.Eq(controlFlowFunctionAppl, exprGen.Integer(BigNum.FromInt(impl.Blocks[0].UniqueId)));
conjecture = exprGen.Implies(eqExpr, conjecture);
}
Macro macro = new Macro(Token.NoToken, descriptiveName, new VariableSeq(), new Formal(Token.NoToken, new TypedIdent(Token.NoToken, "", Type.Bool), false));
proverInterface.DefineMacro(macro, conjecture);
conjecture = exprGen.Function(macro);
if (CommandLineOptions.Clo.vcVariety == CommandLineOptions.VCVariety.Local) {
handler = new VCGen.ErrorReporterLocal(gotoCmdOrigins, label2absy, impl.Blocks, vcgen.incarnationOriginMap, collector, mvInfo, proverInterface.Context, program);
}
else {
handler = new VCGen.ErrorReporter(gotoCmdOrigins, label2absy, impl.Blocks, vcgen.incarnationOriginMap, collector, mvInfo, proverInterface.Context, program);
}
this.houdini = houdini;
this.implementation = impl;
}
private VCExpr BuildAxiom(ProverInterface proverInterface, Dictionary<Variable, bool> currentAssignment) {
ProverContext proverContext = proverInterface.Context;
Boogie2VCExprTranslator exprTranslator = proverContext.BoogieExprTranslator;
VCExpressionGenerator exprGen = proverInterface.VCExprGen;
VCExpr expr = VCExpressionGenerator.True;
foreach (KeyValuePair<Variable, bool> kv in currentAssignment) {
Variable constant = kv.Key;
VCExprVar exprVar = exprTranslator.LookupVariable(constant);
if (kv.Value) {
expr = exprGen.And(expr, exprVar);
}
else {
expr = exprGen.And(expr, exprGen.Not(exprVar));
}
}
/*
foreach (Variable constant in this.houdiniConstants) {
VCExprVar exprVar = exprTranslator.LookupVariable(constant);
if (currentAssignment[constant]) {
expr = exprGen.And(expr, exprVar);
}
else {
expr = exprGen.And(expr, exprGen.Not(exprVar));
}
}
*/
return expr;
}
public ProverInterface.Outcome Verify(ProverInterface proverInterface, Dictionary<Variable, bool> assignment, out List<Counterexample> errors) {
collector.examples.Clear();
if (CommandLineOptions.Clo.Trace) {
Console.WriteLine("Verifying " + descriptiveName);
}
DateTime now = DateTime.UtcNow;
VCExpr vc = proverInterface.VCExprGen.Implies(BuildAxiom(proverInterface, assignment), conjecture);
proverInterface.BeginCheck(descriptiveName, vc, handler);
ProverInterface.Outcome proverOutcome = proverInterface.CheckOutcome(handler);
double queryTime = (DateTime.UtcNow - now).TotalSeconds;
proverTime += queryTime;
numProverQueries++;
if (CommandLineOptions.Clo.Trace) {
Console.WriteLine("Time taken = " + queryTime);
}
errors = collector.examples;
return proverOutcome;
}
public void UpdateUnsatCore(ProverInterface proverInterface, Dictionary<Variable, bool> assignment) {
DateTime now = DateTime.UtcNow;
Boogie2VCExprTranslator exprTranslator = proverInterface.Context.BoogieExprTranslator;
proverInterface.Push();
proverInterface.Assert(conjecture, false);
foreach (var v in assignment.Keys) {
if (assignment[v]) continue;
proverInterface.Assert(exprTranslator.LookupVariable(v), false);
}
List<Variable> assumptionVars = new List<Variable>();
List<VCExpr> assumptionExprs = new List<VCExpr>();
foreach (var v in assignment.Keys) {
if (!assignment[v]) continue;
assumptionVars.Add(v);
assumptionExprs.Add(exprTranslator.LookupVariable(v));
}
List<int> unsatCore;
ProverInterface.Outcome tmp = proverInterface.CheckAssumptions(assumptionExprs, out unsatCore, handler);
System.Diagnostics.Debug.Assert(tmp == ProverInterface.Outcome.Valid);
unsatCoreSet = new HashSet<Variable>();
foreach (int i in unsatCore)
unsatCoreSet.Add(assumptionVars[i]);
proverInterface.Pop();
double unsatCoreQueryTime = (DateTime.UtcNow - now).TotalSeconds;
unsatCoreProverTime += unsatCoreQueryTime;
numUnsatCoreProverQueries++;
}
}
}
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