public static HashSet <string> RunHoudini(Program program, bool RobustAgainstEvaluate = false)
{
HoudiniStats.Reset();
HoudiniInlining.RobustAgainstEvaluate = DualHoudini? false : RobustAgainstEvaluate;
if (DualHoudini && CommandLineOptions.Clo.InlineDepth > 0)
{
throw new DualHoudiniFail("InlineDepth not supported");
}
// Gather existential constants
var CandidateConstants = new Dictionary <string, Constant>();
program.TopLevelDeclarations.OfType <Constant>()
.Where(c => QKeyValue.FindBoolAttribute(c.Attributes, "existential"))
.Iter(c => CandidateConstants.Add(c.Name, c));
// Create a function, one for each impl, for book-keeping
var CandidateFuncsAssumed = new Dictionary <string, Function>();
var CandidateFuncsAsserted = new Dictionary <string, Function>();
var AssumeToAssert = new Dictionary <Function, Function>();
program.TopLevelDeclarations.OfType <Implementation>()
.Iter(impl =>
{
var fassumed = GetCandidateFunc(CandidateFuncPrefix, impl.Name);
var fasserted = GetCandidateFunc(CandidateFuncAssertedPrefix, impl.Name);
CandidateFuncsAssumed.Add(impl.Name, fassumed);
CandidateFuncsAsserted.Add(impl.Name, fasserted);
AssumeToAssert.Add(fassumed, fasserted);
});
// Tag the ensures so we can keep track of them
var iterimpls = program.TopLevelDeclarations.OfType <Implementation>().ToList();
iterimpls.Iter(impl => InstrumentEnsures(program, impl, CandidateFuncsAssumed[impl.Name], CandidateConstants));
//BoogieUtil.PrintProgram(program, "h2.bpl");
var RewriteAssumedToAssertedAction = new Action <Implementation>(impl =>
{
// Rewrite functions that are asserted
var rewrite = new RewriteFuncs(AssumeToAssert);
foreach (var blk in impl.Blocks)
{
foreach (var acmd in blk.Cmds.OfType <AssertCmd>())
{
acmd.Expr = rewrite.VisitExpr(acmd.Expr);
}
}
var funcs = new HashSet <Function>(CandidateFuncsAssumed.Values);
// Move call-site constant to the first argument of CandidateFuncs
foreach (var blk in impl.Blocks)
{
Expr cv = null;
// walk backwards
for (int i = blk.Cmds.Count - 1; i >= 0; i--)
{
var acmd = blk.Cmds[i] as AssumeCmd;
if (acmd == null)
{
continue;
}
if (QKeyValue.FindBoolAttribute(acmd.Attributes, StratifiedVCGenBase.callSiteVarAttr))
{
cv = acmd.Expr;
continue;
}
InsertControlVar.Apply(acmd.Expr, funcs, cv);
}
}
//impl.Emit(new TokenTextWriter(Console.Out), 0);
});
program.AddTopLevelDeclarations(CandidateFuncsAssumed.Values);
program.AddTopLevelDeclarations(CandidateFuncsAsserted.Values);
var callgraph = BoogieUtil.GetCallGraph(program);
var impl2Priority = DeterminePriorityOrder(program, callgraph);
var impls = new HashSet <string>(impl2Priority.Keys);
HoudiniStats.Start("VCGen");
// VC Gen
var hi = new HoudiniInlining(program, CommandLineOptions.Clo.ProverLogFilePath, CommandLineOptions.Clo.ProverLogFileAppend, RewriteAssumedToAssertedAction);
HoudiniStats.Stop("VCGen");
var worklist = new SortedSet <Tuple <int, string> >();
impl2Priority.Iter(tup => worklist.Add(Tuple.Create(tup.Value, tup.Key)));
// Current assignment: set of true constants
// Initially: everything is true
var assignment = new HashSet <string>(CandidateConstants.Keys);
var prover = hi.prover;
var reporter = new EmptyErrorReporter();
// assert true to flush all one-time axioms, decls, etc
prover.Assert(VCExpressionGenerator.True, true);
HoudiniStats.Start("MainLoop");
// worklist algorithm
while (worklist.Any())
{
var implName = worklist.First().Item2;
worklist.Remove(worklist.First());
if (dbg)
{
Console.WriteLine("Processing " + implName);
}
prover.LogComment("Processing " + implName);
prover.Push();
var hvc = new HoudiniVC(hi.implName2StratifiedInliningInfo[implName], impls, assignment);
var openCallSites = new HashSet <StratifiedCallSite>(hvc.CallSites);
prover.Assert(hvc.vcexpr, true);
var candidates = !DualHoudini ? new HashSet <string>(hvc.constantToAssertedExpr.Keys.Where(k => assignment.Contains(k))) :
new HashSet <string>(hvc.constantToAssumedExpr.Select(t => t.Item1).Where(k => assignment.Contains(k)));
var provedTrue = new HashSet <string>();
var provedFalse = new HashSet <string>();
var idepth = Math.Max(0, CommandLineOptions.Clo.InlineDepth);
// iterate over idepth
while (true)
{
// Part 1: over-approximate
var proved = ProveCandidates(prover, hvc.constantToAssertedExpr, hvc.constantToAssumedExpr, candidates.Difference(provedTrue.Union(provedFalse)));
provedTrue.UnionWith(proved);
if (dbg)
{
Console.WriteLine("Proved {0} candiates at depth {1}", proved.Count, CommandLineOptions.Clo.InlineDepth - idepth);
}
if (idepth == 0 || openCallSites.Count == 0)
{
break;
}
// Part 2: under-approximate
prover.Push();
foreach (var cs in openCallSites)
{
prover.Assert(cs.callSiteExpr, false);
}
var remaining = candidates.Difference(provedTrue.Union(provedFalse));
proved = ProveCandidates(prover, hvc.constantToAssertedExpr, hvc.constantToAssumedExpr, remaining);
provedFalse.UnionWith(remaining.Difference(proved));
if (dbg)
{
Console.WriteLine("Disproved {0} candiates at depth {1}", remaining.Difference(proved).Count, CommandLineOptions.Clo.InlineDepth - idepth);
}
prover.Pop();
// resolved all?
if (candidates.Difference(provedTrue.Union(provedFalse)).Count == 0)
{
break;
}
// Inline one level
idepth--;
var nextOpenCallSites = new HashSet <StratifiedCallSite>();
foreach (var cs in openCallSites)
{
var callee = new HoudiniVC(hi.implName2StratifiedInliningInfo[cs.callSite.calleeName], impls, assignment);
var calleevc = cs.Attach(callee);
prover.Assert(prover.VCExprGen.Implies(cs.callSiteExpr, calleevc), true);
nextOpenCallSites.UnionWith(callee.CallSites);
}
openCallSites = nextOpenCallSites;
}
prover.Pop();
var failed = candidates.Difference(provedTrue);
assignment.ExceptWith(failed);
if (failed.Count != 0)
{
// add dependencies back into the worklist
if (!DualHoudini)
{
foreach (var caller in callgraph.Predecessors(implName))
{
worklist.Add(Tuple.Create(impl2Priority[caller], caller));
}
}
else
{
foreach (var caller in callgraph.Successors(implName))
{
worklist.Add(Tuple.Create(impl2Priority[caller], caller));
}
}
}
}
HoudiniStats.Stop("MainLoop");
hi.Close();
return(assignment);
}
// Prove candidates that hold (using an over-approximation, at the current inline depth).
// Return the set of candidates proved correct
static HashSet <string> ProveCandidates(ProverInterface prover, Dictionary <string, VCExpr> constantToAssertedExpr, List <Tuple <string, VCExpr, VCExpr> > constantToAssumedExpr, HashSet <string> candidates)
{
var remaining = new HashSet <string>(candidates);
var reporter = new EmptyErrorReporter();
var failed = new HashSet <string>();
// for dual houdini, we have to iterate once around to the loop
// even if remaining is empty
bool secondtry = false;
while (true)
{
remaining.ExceptWith(failed);
if (remaining.Count == 0 && (!DualHoudini || secondtry))
{
break;
}
if (remaining.Count == 0)
{
secondtry = true;
}
else
{
secondtry = false;
}
HoudiniStats.ProverCount++;
HoudiniStats.Start("ProverTime");
prover.Push();
var nameToCallSiteVar = new Dictionary <string, VCExprVar>();
var callSiteVarToConstantToExpr = new Dictionary <string, Dictionary <string, VCExpr> >();
if (!DualHoudini)
{
// assert post
VCExpr toassert = VCExpressionGenerator.True;
foreach (var k in remaining)
{
toassert = prover.VCExprGen.And(toassert, constantToAssertedExpr[k]);
}
prover.Assert(toassert, false);
}
else
{
// assume post of callees
foreach (var tup in constantToAssumedExpr)
{
if (!remaining.Contains(tup.Item1))
{
continue;
}
var csVar = tup.Item2 as VCExprVar;
Debug.Assert(csVar != null);
if (!nameToCallSiteVar.ContainsKey(csVar.ToString()))
{
nameToCallSiteVar.Add(csVar.ToString(), csVar);
}
if (!callSiteVarToConstantToExpr.ContainsKey(csVar.ToString()))
{
callSiteVarToConstantToExpr.Add(csVar.ToString(), new Dictionary <string, VCExpr>());
}
callSiteVarToConstantToExpr[csVar.ToString()].Add(tup.Item1, tup.Item3);
}
foreach (var tup in callSiteVarToConstantToExpr)
{
var expr = VCExpressionGenerator.False;
tup.Value.Values.Iter(e => expr = prover.VCExprGen.Or(expr, e));
prover.Assert(prover.VCExprGen.Implies(nameToCallSiteVar[tup.Key], expr), true);
}
}
Dictionary <string, VCExprVar> recordingBool = null;
if (RobustAgainstEvaluate)
{
recordingBool = new Dictionary <string, VCExprVar>();
VCExpr torecord = VCExpressionGenerator.True;
foreach (var k in remaining)
{
var b = prover.VCExprGen.Variable("recordingVar_" + k, Microsoft.Boogie.Type.Bool);
recordingBool.Add(k, b);
torecord = prover.VCExprGen.And(torecord, prover.VCExprGen.Eq(b, constantToAssertedExpr[k]));
}
prover.Assert(torecord, true);
}
prover.Check();
var outcome = prover.CheckOutcomeCore(reporter);
// check which ones failed
if (outcome == ProverInterface.Outcome.Invalid || outcome == ProverInterface.Outcome.Undetermined)
{
var removed = 0;
if (!DualHoudini)
{
foreach (var k in remaining)
{
var b = recordingBool == null ? (bool)prover.Evaluate(constantToAssertedExpr[k])
: (bool)prover.Evaluate(recordingBool[k]);
if (!b)
{
failed.Add(k);
if (dbg)
{
Console.WriteLine("Failed: {0}", k);
}
removed++;
}
}
}
else
{
foreach (var tup in callSiteVarToConstantToExpr)
{
if (!(bool)prover.Evaluate(nameToCallSiteVar[tup.Key]))
{
continue;
}
// call site taken
foreach (var tup2 in tup.Value)
{
if ((bool)prover.Evaluate(tup2.Value))
{
failed.Add(tup2.Key);
if (dbg)
{
Console.WriteLine("Failed: {0}", tup2.Key);
}
removed++;
}
}
}
if (removed == 0)
{
throw new DualHoudiniFail("Nothing to drop");
}
}
Debug.Assert(removed != 0);
//if(dbg) Console.WriteLine("Query {0}: Invalid, {1} removed", HoudiniStats.ProverCount, removed);
}
HoudiniStats.Stop("ProverTime");
prover.Pop();
if (outcome == ProverInterface.Outcome.TimeOut || outcome == ProverInterface.Outcome.OutOfMemory)
{
if (DualHoudini)
{
throw new DualHoudiniFail("Timeout");
}
failed.UnionWith(remaining);
break;
}
if (outcome == ProverInterface.Outcome.Valid)
{
//if(dbg) Console.WriteLine("Query {0}: Valid", HoudiniStats.ProverCount);
break;
}
}
remaining.ExceptWith(failed);
return(remaining);
}
