private void BuildTransferFunctions()
{
foreach (CFGNode node in ProgramCFG.CfgNodes)
{
if (node is CFGNodeStatement)
{
if ((node is CFGNodeStmtSkip) || (node is CFGNodeStmtPrint) ||
(node is CFGNodeStmtGoto) || (node is CFGNodeStmtReturn))
{
(node as CFGNodeStatement).Transfer = HelperFunctions.BuildIdentityTransfer(m_BddManager,
(node as CFGNodeStatement).ProcOf.LocalVariables.VariablesToId,
ProgramCFG.GlobalVariables.VariablesToId);
}
else
if (node is CFGNodeStmtAssignment)
{
(node as CFGNodeStmtAssignment).Transfer =
CFGNodeStmtAssignment.BuildAssignmentTransfer(node.GetAST(), m_BddManager,
(node as CFGNodeStatement).ProcOf.LocalVariables.VariablesToId,
ProgramCFG.GlobalVariables.VariablesToId);
}
else
if (node is CFGNodeStmtConditional)
{
Bdd TransferTrue, TransferFalse;
CommonAST decider = node.GetAST().getFirstChild() as CommonAST;
HelperFunctions.BuildDeciderTransfers(decider, m_BddManager,
(node as CFGNodeStatement).ProcOf.LocalVariables.VariablesToId,
ProgramCFG.GlobalVariables.VariablesToId, out TransferTrue, out TransferFalse);
(node as CFGNodeStmtConditional).TransferTrue = TransferTrue;
(node as CFGNodeStmtConditional).TransferFalse = TransferFalse;
}
else
if (node is CFGNodeStmtProcCall)
{
CFGNodeProcedure procedureCalled;
if (!(ProgramCFG.ProcedureNameToNode().TryGetValue(
node.GetAST().getFirstChild().getText(), out procedureCalled)))
{
System.Diagnostics.Debug.Assert(false);
}
(node as CFGNodeStmtProcCall).Transfer =
CFGNodeStmtProcCall.buildProcCallTransfer(node.GetAST(), procedureCalled, m_BddManager,
(node as CFGNodeStatement).ProcOf.LocalVariables.VariablesToId,
ProgramCFG.GlobalVariables.VariablesToId);
}
}
}
}
public void Reachable(debugPrintDelegate debugPrint)
{
if (ProgramCFG.CfgNodes.Count <= 1)
{
debugPrint("Invalid Program, unable to proceed!\n");
return;
}
m_PathEdges.Clear();
m_SummaryEdges.Clear();
BuildTransferFunctions();
LinkedList <CFGNode> workList = new LinkedList <CFGNode>();
CFGNodeProcedure tempNodeProc;
CFGNode tempNode;
Bdd bddLift, bddSummaryEdges, bddNew;
PathEdges bddSelfLoop, bddJoin, bddPathEdges;
Bdd [] array = new Bdd[3];
foreach (CFGNode node in ProgramCFG.CfgNodes)
{
m_PathEdges.Add(node, new PathEdges());
m_SummaryEdges.Add(node, m_BddManager.CreateBddZero());
}
ProgramCFG.ProcedureNameToNode().TryGetValue("main", out tempNodeProc);
workList.AddFirst(tempNodeProc.FirstStmtOf);
m_PathEdges.Remove(tempNodeProc.FirstStmtOf);
PathEdges firstMain = new PathEdges();
firstMain.AddPathEdge(new PathEdgesPartition(0, HelperFunctions.BuildIdentityTransfer
(m_BddManager, tempNodeProc.LocalVariables.VariablesToId, ProgramCFG.GlobalVariables.VariablesToId)), m_BddManager);
m_PathEdges.Add(tempNodeProc.FirstStmtOf, firstMain);
#region Debug part of the reachability algorithm
/*
* ///////Debug ////////////
* Dictionary<string, int>.ValueCollection valCollection = tempNodeProc.LocalVariables.VariablesToId.Values;
* foreach (int id in valCollection)
* {
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalOr(tempBdd, m_BddManager.GetBddVariableWithID(id));
* tempBdd1.FreeBdd();
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalXnor(tempBdd, m_BddManager.GetBddVariableWithID(id + 2));
* tempBdd1.FreeBdd();
* }
*
* foreach (int id in ProgramCFG.GlobalVariables.VariablesToId.Values)
* {
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalImplies(tempBdd, m_BddManager.GetBddVariableWithID(id));
* tempBdd1.FreeBdd();
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalOr(tempBdd, m_BddManager.GetBddVariableWithID(id + 2));
* tempBdd1.FreeBdd();
* }
* array[0] = tempBdd;
* tempBdd = m_BddManager.CreateBddOne();
*
* foreach (int id in valCollection)
* {
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalAnd(tempBdd, m_BddManager.GetBddVariableWithID(id));
* tempBdd1.FreeBdd();
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalNor(tempBdd, m_BddManager.GetBddVariableWithID(id + 2));
* tempBdd1.FreeBdd();
* }
*
* foreach (int id in ProgramCFG.GlobalVariables.VariablesToId.Values)
* {
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalImplies(tempBdd, m_BddManager.GetBddVariableWithID(id));
* tempBdd1.FreeBdd();
* tempBdd1 = tempBdd;
* tempBdd = m_BddManager.LogicalXor(tempBdd, m_BddManager.GetBddVariableWithID(id + 2));
* tempBdd1.FreeBdd();
* }
* array[1] = tempBdd;
*
* //array[2] = Join(array[0], array[1], tempNodeProc.LocalVariables);
* array[2] = SelfLoop(array[1], tempNodeProc.LocalVariables, tempNodeProc.LocalVariables);
* m_BddManager.ForceGarbageCollection();
* return array;
* ////////////////////////
*/
#endregion
while (workList.Count != 0)
{
tempNode = workList.First.Value;
debugPrint("Processing Node: " + tempNode.ToString() + ".\n");
workList.RemoveFirst();
if (tempNode is CFGNodeStmtProcCall)
{
CFGNodeStmtProcCall procCall = tempNode as CFGNodeStmtProcCall;
m_PathEdges.TryGetValue(tempNode, out bddPathEdges);
bddJoin = Join(bddPathEdges, procCall.Transfer, procCall.ProcOf.LocalVariables);
bddSelfLoop = SelfLoop(bddJoin, procCall.ProcOf.LocalVariables, (procCall.Succesor as CFGNodeStatement).ProcOf.LocalVariables);
Propagate(procCall.Succesor, bddSelfLoop, workList);
bddJoin.FreeAllBdd();
bddSelfLoop.FreeAllBdd();
m_PathEdges.TryGetValue(tempNode, out bddPathEdges);
m_SummaryEdges.TryGetValue(tempNode, out bddSummaryEdges);
if (bddSummaryEdges != null)
{
bddJoin = Join(bddPathEdges, bddSummaryEdges, procCall.ProcOf.LocalVariables);
Propagate(procCall.ReturnPoint, bddJoin, workList);
bddJoin.FreeAllBdd();
}
}
else if (tempNode is CFGNodeProcedure)
{
foreach (CFGNodeStmtSkip node in (tempNode as CFGNodeProcedure).Succesor)
{
bddLift = Lift(node.previousProcCall, tempNode as CFGNodeProcedure);
m_SummaryEdges.TryGetValue(node.previousProcCall, out bddSummaryEdges);
m_PathEdges.TryGetValue(node.previousProcCall, out bddPathEdges);
if (bddSummaryEdges != null)
{
bddNew = m_BddManager.LogicalOr(bddLift, bddSummaryEdges);
bddLift.FreeBdd();
}
else
{
bddNew = bddLift;
}
if (bddSummaryEdges != bddNew)
{
m_SummaryEdges.Remove(node.previousProcCall);
m_SummaryEdges.Add(node.previousProcCall, bddNew);
bddSummaryEdges.FreeBdd();
bddJoin = Join(bddPathEdges, bddNew, (node as CFGNodeStmtSkip).previousProcCall.ProcOf.LocalVariables);
Propagate(node, bddJoin, workList);
bddJoin.FreeAllBdd();
}
}
}
else if (tempNode is CFGNodeStmtConditional)
{
CFGNodeStmtConditional tempNode1 = tempNode as CFGNodeStmtConditional;
m_PathEdges.TryGetValue(tempNode, out bddPathEdges);
bddJoin = Join(bddPathEdges, tempNode1.TransferTrue, tempNode1.ProcOf.LocalVariables);
Propagate(tempNode1.TrueSuccesor, bddJoin, workList);
bddJoin.FreeAllBdd();
m_PathEdges.TryGetValue(tempNode, out bddPathEdges);
bddJoin = Join(bddPathEdges, tempNode1.TransferFalse, tempNode1.ProcOf.LocalVariables);
Propagate(tempNode1.FalseSuccesor, bddJoin, workList);
bddJoin.FreeAllBdd();
}
else
{
if (!(tempNode is CFGNodeError))
{
m_PathEdges.TryGetValue(tempNode, out bddPathEdges);
bddJoin = Join(bddPathEdges, (tempNode as CFGNodeStatement).Transfer, (tempNode as CFGNodeStatement).ProcOf.LocalVariables);
Propagate(tempNode.Succesor, bddJoin, workList);
bddJoin.FreeAllBdd();
}
}
}
m_BddManager.ForceGarbageCollection();
}