package Analysis.SSJava;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.Vector;

import Analysis.SSJava.FlowDownCheck.ComparisonResult;
import Analysis.SSJava.FlowDownCheck.CompositeLattice;
import IR.AnnotationDescriptor;
import IR.ClassDescriptor;
import IR.Descriptor;
import IR.FieldDescriptor;
import IR.MethodDescriptor;
import IR.NameDescriptor;
import IR.Operation;
import IR.State;
import IR.SymbolTable;
import IR.TypeDescriptor;
import IR.TypeExtension;
import IR.VarDescriptor;
import IR.Flat.FlatNode;
import IR.Tree.ArrayAccessNode;
import IR.Tree.AssignmentNode;
import IR.Tree.BlockExpressionNode;
import IR.Tree.BlockNode;
import IR.Tree.BlockStatementNode;
import IR.Tree.CastNode;
import IR.Tree.CreateObjectNode;
import IR.Tree.DeclarationNode;
import IR.Tree.ExpressionNode;
import IR.Tree.FieldAccessNode;
import IR.Tree.IfStatementNode;
import IR.Tree.Kind;
import IR.Tree.LiteralNode;
import IR.Tree.LoopNode;
import IR.Tree.MethodInvokeNode;
import IR.Tree.NameNode;
import IR.Tree.OpNode;
import IR.Tree.ReturnNode;
import IR.Tree.SubBlockNode;
import IR.Tree.SwitchBlockNode;
import IR.Tree.SwitchStatementNode;
import IR.Tree.SynchronizedNode;
import IR.Tree.TertiaryNode;
import IR.Tree.TreeNode;
import Util.Pair;

public class FlowDownCheck {

  State state;
  static SSJavaAnalysis ssjava;

  Set<ClassDescriptor> toanalyze;
  List<ClassDescriptor> toanalyzeList;

  Set<MethodDescriptor> toanalyzeMethod;
  List<MethodDescriptor> toanalyzeMethodList;

  // mapping from 'descriptor' to 'composite location'
  Hashtable<Descriptor, CompositeLocation> d2loc;

  Hashtable<MethodDescriptor, CompositeLocation> md2ReturnLoc;
  Hashtable<MethodDescriptor, ReturnLocGenerator> md2ReturnLocGen;

  // mapping from 'locID' to 'class descriptor'
  Hashtable<String, ClassDescriptor> fieldLocName2cd;

  boolean deterministic = true;

  public FlowDownCheck(SSJavaAnalysis ssjava, State state) {
    this.ssjava = ssjava;
    this.state = state;
    if (deterministic) {
      this.toanalyzeList = new ArrayList<ClassDescriptor>();
    } else {
      this.toanalyze = new HashSet<ClassDescriptor>();
    }
    if (deterministic) {
      this.toanalyzeMethodList = new ArrayList<MethodDescriptor>();
    } else {
      this.toanalyzeMethod = new HashSet<MethodDescriptor>();
    }
    this.d2loc = new Hashtable<Descriptor, CompositeLocation>();
    this.fieldLocName2cd = new Hashtable<String, ClassDescriptor>();
    this.md2ReturnLoc = new Hashtable<MethodDescriptor, CompositeLocation>();
    this.md2ReturnLocGen = new Hashtable<MethodDescriptor, ReturnLocGenerator>();
  }

  public void init() {

    // construct mapping from the location name to the class descriptor
    // assume that the location name is unique through the whole program

    Set<ClassDescriptor> cdSet = ssjava.getCd2lattice().keySet();
    for (Iterator iterator = cdSet.iterator(); iterator.hasNext();) {
      ClassDescriptor cd = (ClassDescriptor) iterator.next();
      SSJavaLattice<String> lattice = ssjava.getCd2lattice().get(cd);
      Set<String> fieldLocNameSet = lattice.getKeySet();

      for (Iterator iterator2 = fieldLocNameSet.iterator(); iterator2.hasNext();) {
        String fieldLocName = (String) iterator2.next();
        fieldLocName2cd.put(fieldLocName, cd);
      }

    }

  }

  public boolean toAnalyzeIsEmpty() {
    if (deterministic) {
      return toanalyzeList.isEmpty();
    } else {
      return toanalyze.isEmpty();
    }
  }

  public ClassDescriptor toAnalyzeNext() {
    if (deterministic) {
      return toanalyzeList.remove(0);
    } else {
      ClassDescriptor cd = toanalyze.iterator().next();
      toanalyze.remove(cd);
      return cd;
    }
  }

  public void setupToAnalyze() {
    SymbolTable classtable = state.getClassSymbolTable();
    if (deterministic) {
      toanalyzeList.clear();
      toanalyzeList.addAll(classtable.getValueSet());
      Collections.sort(toanalyzeList, new Comparator<ClassDescriptor>() {
        public int compare(ClassDescriptor o1, ClassDescriptor o2) {
          return o1.getClassName().compareToIgnoreCase(o2.getClassName());
        }
      });
    } else {
      toanalyze.clear();
      toanalyze.addAll(classtable.getValueSet());
    }
  }

  public void setupToAnalazeMethod(ClassDescriptor cd) {

    SymbolTable methodtable = cd.getMethodTable();
    if (deterministic) {
      toanalyzeMethodList.clear();
      toanalyzeMethodList.addAll(methodtable.getValueSet());
      Collections.sort(toanalyzeMethodList, new Comparator<MethodDescriptor>() {
        public int compare(MethodDescriptor o1, MethodDescriptor o2) {
          return o1.getSymbol().compareToIgnoreCase(o2.getSymbol());
        }
      });
    } else {
      toanalyzeMethod.clear();
      toanalyzeMethod.addAll(methodtable.getValueSet());
    }
  }

  public boolean toAnalyzeMethodIsEmpty() {
    if (deterministic) {
      return toanalyzeMethodList.isEmpty();
    } else {
      return toanalyzeMethod.isEmpty();
    }
  }

  public MethodDescriptor toAnalyzeMethodNext() {
    if (deterministic) {
      return toanalyzeMethodList.remove(0);
    } else {
      MethodDescriptor md = toanalyzeMethod.iterator().next();
      toanalyzeMethod.remove(md);
      return md;
    }
  }

  public void flowDownCheck() {

    // phase 1 : checking declaration node and creating mapping of 'type
    // desciptor' & 'location'
    setupToAnalyze();

    while (!toAnalyzeIsEmpty()) {
      ClassDescriptor cd = toAnalyzeNext();

      if (ssjava.needToBeAnnoated(cd)) {

        ClassDescriptor superDesc = cd.getSuperDesc();

        if (superDesc != null && (!superDesc.getSymbol().equals("Object"))) {
          checkOrderingInheritance(superDesc, cd);
        }

        checkDeclarationInClass(cd);

        setupToAnalazeMethod(cd);
        while (!toAnalyzeMethodIsEmpty()) {
          MethodDescriptor md = toAnalyzeMethodNext();
          if (ssjava.needTobeAnnotated(md)) {
            checkDeclarationInMethodBody(cd, md);
          }
        }

      }

    }

    // phase2 : checking assignments
    setupToAnalyze();

    while (!toAnalyzeIsEmpty()) {
      ClassDescriptor cd = toAnalyzeNext();

      setupToAnalazeMethod(cd);
      while (!toAnalyzeMethodIsEmpty()) {
        MethodDescriptor md = toAnalyzeMethodNext();
        if (ssjava.needTobeAnnotated(md)) {
          if (state.SSJAVADEBUG) {
            System.out.println("SSJAVA: Checking Flow-down Rules: " + md);
          }
          CompositeLocation calleePCLOC = ssjava.getPCLocation(md);
          checkMethodBody(cd, md, calleePCLOC);
        }
      }
    }

  }

  private void checkOrderingInheritance(ClassDescriptor superCd, ClassDescriptor cd) {
    // here, we're going to check that sub class keeps same relative orderings
    // in respect to super class

    SSJavaLattice<String> superLattice = ssjava.getClassLattice(superCd);
    SSJavaLattice<String> subLattice = ssjava.getClassLattice(cd);

    if (superLattice != null) {
      // if super class doesn't define lattice, then we don't need to check its
      // subclass
      if (subLattice == null) {
        throw new Error("If a parent class '" + superCd
            + "' has a ordering lattice, its subclass '" + cd + "' should have one.");
      }

      Set<Pair<String, String>> superPairSet = superLattice.getOrderingPairSet();
      Set<Pair<String, String>> subPairSet = subLattice.getOrderingPairSet();

      for (Iterator iterator = superPairSet.iterator(); iterator.hasNext();) {
        Pair<String, String> pair = (Pair<String, String>) iterator.next();

        if (!subPairSet.contains(pair)) {
          throw new Error("Subclass '" + cd + "' does not have the relative ordering '"
              + pair.getSecond() + " < " + pair.getFirst()
              + "' that is defined by its superclass '" + superCd + "'.");
        }
      }
    }

    MethodLattice<String> superMethodDefaultLattice = ssjava.getMethodDefaultLattice(superCd);
    MethodLattice<String> subMethodDefaultLattice = ssjava.getMethodDefaultLattice(cd);

    if (superMethodDefaultLattice != null) {
      if (subMethodDefaultLattice == null) {
        throw new Error("When a parent class '" + superCd
            + "' defines a default method lattice, its subclass '" + cd + "' should define one.");
      }

      Set<Pair<String, String>> superPairSet = superMethodDefaultLattice.getOrderingPairSet();
      Set<Pair<String, String>> subPairSet = subMethodDefaultLattice.getOrderingPairSet();

      for (Iterator iterator = superPairSet.iterator(); iterator.hasNext();) {
        Pair<String, String> pair = (Pair<String, String>) iterator.next();

        if (!subPairSet.contains(pair)) {
          throw new Error("Subclass '" + cd + "' does not have the relative ordering '"
              + pair.getSecond() + " < " + pair.getFirst()
              + "' that is defined by its superclass '" + superCd
              + "' in the method default lattice.");
        }
      }

    }

  }

  public Hashtable getMap() {
    return d2loc;
  }

  private void checkDeclarationInMethodBody(ClassDescriptor cd, MethodDescriptor md) {
    BlockNode bn = state.getMethodBody(md);

    // first, check annotations on method parameters
    List<CompositeLocation> paramList = new ArrayList<CompositeLocation>();
    for (int i = 0; i < md.numParameters(); i++) {
      // process annotations on method parameters
      VarDescriptor vd = (VarDescriptor) md.getParameter(i);
      assignLocationOfVarDescriptor(vd, md, md.getParameterTable(), null);
      paramList.add(d2loc.get(vd));
    }
    Vector<AnnotationDescriptor> methodAnnotations = md.getModifiers().getAnnotations();

    CompositeLocation returnLocComp = null;

    boolean hasReturnLocDeclaration = false;
    if (methodAnnotations != null) {
      for (int i = 0; i < methodAnnotations.size(); i++) {
        AnnotationDescriptor an = methodAnnotations.elementAt(i);
        if (an.getMarker().equals(ssjava.RETURNLOC)) {
          // this case, developer explicitly defines method lattice
          String returnLocDeclaration = an.getValue();
          returnLocComp = parseLocationDeclaration(md, null, returnLocDeclaration);
          hasReturnLocDeclaration = true;
        } else if (an.getMarker().equals(ssjava.THISLOC)) {
          String thisLoc = an.getValue();
          ssjava.getMethodLattice(md).setThisLoc(thisLoc);
        } else if (an.getMarker().equals(ssjava.GLOBALLOC)) {
          String globalLoc = an.getValue();
          ssjava.getMethodLattice(md).setGlobalLoc(globalLoc);
        } else if (an.getMarker().equals(ssjava.PCLOC)) {
          String pcLocDeclaration = an.getValue();
          ssjava.setPCLocation(md, parseLocationDeclaration(md, null, pcLocDeclaration));
        }
      }
    }

    // second, check return location annotation
    if (!md.getReturnType().isVoid() && !ssjava.getMethodContainingSSJavaLoop().equals(md)) {
      if (!hasReturnLocDeclaration) {
        // if developer does not define method lattice
        // search return location in the method default lattice
        String rtrStr = ssjava.getMethodLattice(md).getReturnLoc();
        if (rtrStr != null) {
          returnLocComp = new CompositeLocation(new Location(md, rtrStr));
        }
      }

      if (returnLocComp == null) {
        throw new Error("Return location is not specified for the method " + md + " at "
            + cd.getSourceFileName());
      }

      md2ReturnLoc.put(md, returnLocComp);

    }

    if (!md.getReturnType().isVoid() && !ssjava.getMethodContainingSSJavaLoop().equals(md)) {
      MethodLattice<String> methodLattice = ssjava.getMethodLattice(md);
      String thisLocId = methodLattice.getThisLoc();
      if ((!md.isStatic())) {

        if (thisLocId == null) {
          throw new Error("Method '" + md + "' does not have the definition of 'this' location at "
              + md.getClassDesc().getSourceFileName());
        }

        CompositeLocation thisLoc = new CompositeLocation(new Location(md, thisLocId));
        paramList.add(0, thisLoc);

      }

      md2ReturnLocGen.put(md, new ReturnLocGenerator(md2ReturnLoc.get(md), md, paramList, md
          + " of " + cd.getSourceFileName()));

    }

    // fourth, check declarations inside of method

    checkDeclarationInBlockNode(md, md.getParameterTable(), bn);

  }

  private void checkDeclarationInBlockNode(MethodDescriptor md, SymbolTable nametable, BlockNode bn) {
    bn.getVarTable().setParent(nametable);
    for (int i = 0; i < bn.size(); i++) {
      BlockStatementNode bsn = bn.get(i);
      checkDeclarationInBlockStatementNode(md, bn.getVarTable(), bsn);
    }
  }

  private void checkDeclarationInBlockStatementNode(MethodDescriptor md, SymbolTable nametable,
      BlockStatementNode bsn) {

    switch (bsn.kind()) {
    case Kind.SubBlockNode:
      checkDeclarationInSubBlockNode(md, nametable, (SubBlockNode) bsn);
      return;

    case Kind.DeclarationNode:
      checkDeclarationNode(md, nametable, (DeclarationNode) bsn);
      break;

    case Kind.LoopNode:
      checkDeclarationInLoopNode(md, nametable, (LoopNode) bsn);
      break;

    case Kind.IfStatementNode:
      checkDeclarationInIfStatementNode(md, nametable, (IfStatementNode) bsn);
      return;

    case Kind.SwitchStatementNode:
      checkDeclarationInSwitchStatementNode(md, nametable, (SwitchStatementNode) bsn);
      return;

    case Kind.SynchronizedNode:
      checkDeclarationInSynchronizedNode(md, nametable, (SynchronizedNode) bsn);
      return;

    }
  }

  private void checkDeclarationInSynchronizedNode(MethodDescriptor md, SymbolTable nametable,
      SynchronizedNode sbn) {
    checkDeclarationInBlockNode(md, nametable, sbn.getBlockNode());
  }

  private void checkDeclarationInSwitchStatementNode(MethodDescriptor md, SymbolTable nametable,
      SwitchStatementNode ssn) {
    BlockNode sbn = ssn.getSwitchBody();
    for (int i = 0; i < sbn.size(); i++) {
      SwitchBlockNode node = (SwitchBlockNode) sbn.get(i);
      checkDeclarationInBlockNode(md, nametable, node.getSwitchBlockStatement());
    }
  }

  private void checkDeclarationInIfStatementNode(MethodDescriptor md, SymbolTable nametable,
      IfStatementNode isn) {
    checkDeclarationInBlockNode(md, nametable, isn.getTrueBlock());
    if (isn.getFalseBlock() != null)
      checkDeclarationInBlockNode(md, nametable, isn.getFalseBlock());
  }

  private void checkDeclarationInLoopNode(MethodDescriptor md, SymbolTable nametable, LoopNode ln) {

    if (ln.getType() == LoopNode.FORLOOP) {
      // check for loop case
      ClassDescriptor cd = md.getClassDesc();
      BlockNode bn = ln.getInitializer();
      for (int i = 0; i < bn.size(); i++) {
        BlockStatementNode bsn = bn.get(i);
        checkDeclarationInBlockStatementNode(md, nametable, bsn);
      }
    }

    // check loop body
    checkDeclarationInBlockNode(md, nametable, ln.getBody());
  }

  private void checkMethodBody(ClassDescriptor cd, MethodDescriptor md,
      CompositeLocation constraints) {
    BlockNode bn = state.getMethodBody(md);
    checkLocationFromBlockNode(md, md.getParameterTable(), bn, constraints);
  }

  private String generateErrorMessage(ClassDescriptor cd, TreeNode tn) {
    if (tn != null) {
      return cd.getSourceFileName() + "::" + tn.getNumLine();
    } else {
      return cd.getSourceFileName();
    }

  }

  private CompositeLocation checkLocationFromBlockNode(MethodDescriptor md, SymbolTable nametable,
      BlockNode bn, CompositeLocation constraint) {

    bn.getVarTable().setParent(nametable);
    for (int i = 0; i < bn.size(); i++) {
      BlockStatementNode bsn = bn.get(i);
      checkLocationFromBlockStatementNode(md, bn.getVarTable(), bsn, constraint);
    }
    return new CompositeLocation();

  }

  private CompositeLocation checkLocationFromBlockStatementNode(MethodDescriptor md,
      SymbolTable nametable, BlockStatementNode bsn, CompositeLocation constraint) {

    CompositeLocation compLoc = null;
    switch (bsn.kind()) {
    case Kind.BlockExpressionNode:
      compLoc =
          checkLocationFromBlockExpressionNode(md, nametable, (BlockExpressionNode) bsn, constraint);
      break;

    case Kind.DeclarationNode:
      compLoc = checkLocationFromDeclarationNode(md, nametable, (DeclarationNode) bsn, constraint);
      break;

    case Kind.IfStatementNode:
      compLoc = checkLocationFromIfStatementNode(md, nametable, (IfStatementNode) bsn, constraint);
      break;

    case Kind.LoopNode:
      compLoc = checkLocationFromLoopNode(md, nametable, (LoopNode) bsn, constraint);
      break;

    case Kind.ReturnNode:
      compLoc = checkLocationFromReturnNode(md, nametable, (ReturnNode) bsn, constraint);
      break;

    case Kind.SubBlockNode:
      compLoc = checkLocationFromSubBlockNode(md, nametable, (SubBlockNode) bsn, constraint);
      break;

    case Kind.ContinueBreakNode:
      compLoc = new CompositeLocation();
      break;

    case Kind.SwitchStatementNode:
      compLoc =
          checkLocationFromSwitchStatementNode(md, nametable, (SwitchStatementNode) bsn, constraint);

    }
    return compLoc;
  }

  private CompositeLocation checkLocationFromSwitchStatementNode(MethodDescriptor md,
      SymbolTable nametable, SwitchStatementNode ssn, CompositeLocation constraint) {

    ClassDescriptor cd = md.getClassDesc();
    CompositeLocation condLoc =
        checkLocationFromExpressionNode(md, nametable, ssn.getCondition(), new CompositeLocation(),
            constraint, false);
    BlockNode sbn = ssn.getSwitchBody();

    constraint = generateNewConstraint(constraint, condLoc);

    for (int i = 0; i < sbn.size(); i++) {
      checkLocationFromSwitchBlockNode(md, nametable, (SwitchBlockNode) sbn.get(i), constraint);
    }
    return new CompositeLocation();
  }

  private CompositeLocation checkLocationFromSwitchBlockNode(MethodDescriptor md,
      SymbolTable nametable, SwitchBlockNode sbn, CompositeLocation constraint) {

    CompositeLocation blockLoc =
        checkLocationFromBlockNode(md, nametable, sbn.getSwitchBlockStatement(), constraint);

    return blockLoc;

  }

  private CompositeLocation checkLocationFromReturnNode(MethodDescriptor md, SymbolTable nametable,
      ReturnNode rn, CompositeLocation constraint) {

    if (ssjava.getMethodContainingSSJavaLoop().equals(md)) {
      return new CompositeLocation();
    }

    ExpressionNode returnExp = rn.getReturnExpression();

    CompositeLocation declaredReturnLoc = md2ReturnLoc.get(md);

    CompositeLocation returnValueLoc;
    if (returnExp != null) {
      returnValueLoc =
          checkLocationFromExpressionNode(md, nametable, returnExp, new CompositeLocation(),
              constraint, false);

      // System.out.println("# RETURN VALUE LOC=" + returnValueLoc +
      // " with constraint=" + constraint);

      // TODO: do we need to check here?
      // if this return statement is inside branch, return value has an implicit
      // flow from conditional location
      // if (constraint != null) {
      // Set<CompositeLocation> inputGLB = new HashSet<CompositeLocation>();
      // inputGLB.add(returnValueLoc);
      // inputGLB.add(constraint);
      // returnValueLoc =
      // CompositeLattice.calculateGLB(inputGLB,
      // generateErrorMessage(md.getClassDesc(), rn));
      // }

      if (constraint != null) {

        // Set<CompositeLocation> inputGLB = new HashSet<CompositeLocation>();
        // inputGLB.add(returnValueLoc);
        // inputGLB.add(constraint);
        // returnValueLoc =
        // CompositeLattice.calculateGLB(inputGLB,
        // generateErrorMessage(md.getClassDesc(), rn));

        // if (!returnValueLoc.get(returnValueLoc.getSize() - 1).isTop()) {
        // if (!CompositeLattice.isGreaterThan(constraint, returnValueLoc,
        // generateErrorMessage(md.getClassDesc(), rn))) {
        // System.out.println("returnValueLoc.get(returnValueLoc.getSize() - 1).isTop()="
        // + returnValueLoc.get(returnValueLoc.getSize() - 1).isTop());
        // throw new Error("The value flow from " + constraint + " to " +
        // returnValueLoc
        // + " does not respect location hierarchy on the assignment " +
        // rn.printNode(0)
        // + " at " + md.getClassDesc().getSourceFileName() + "::" +
        // rn.getNumLine());
        // }
        // }

        if (!CompositeLattice.isGreaterThan(constraint, declaredReturnLoc,
            generateErrorMessage(md.getClassDesc(), rn))) {
          throw new Error("The value flow from " + constraint + " to " + declaredReturnLoc
              + " does not respect location hierarchy on the assignment " + rn.printNode(0)
              + " at " + md.getClassDesc().getSourceFileName() + "::" + rn.getNumLine());
        }

      }

      // check if return value is equal or higher than RETRUNLOC of method
      // declaration annotation

      int compareResult =
          CompositeLattice.compare(returnValueLoc, declaredReturnLoc, false,
              generateErrorMessage(md.getClassDesc(), rn));

      if (compareResult == ComparisonResult.LESS || compareResult == ComparisonResult.INCOMPARABLE) {
        throw new Error(
            "Return value location is not equal or higher than the declaraed return location at "
                + md.getClassDesc().getSourceFileName() + "::" + rn.getNumLine());
      }
    }

    return new CompositeLocation();
  }

  private boolean hasOnlyLiteralValue(ExpressionNode en) {
    if (en.kind() == Kind.LiteralNode) {
      return true;
    } else {
      return false;
    }
  }

  private CompositeLocation checkLocationFromLoopNode(MethodDescriptor md, SymbolTable nametable,
      LoopNode ln, CompositeLocation constraint) {

    ClassDescriptor cd = md.getClassDesc();
    if (ln.getType() == LoopNode.WHILELOOP || ln.getType() == LoopNode.DOWHILELOOP) {

      CompositeLocation condLoc =
          checkLocationFromExpressionNode(md, nametable, ln.getCondition(),
              new CompositeLocation(), constraint, false);
      // addLocationType(ln.getCondition().getType(), (condLoc));

      constraint = generateNewConstraint(constraint, condLoc);
      checkLocationFromBlockNode(md, nametable, ln.getBody(), constraint);

      return new CompositeLocation();

    } else {
      // check 'for loop' case
      BlockNode bn = ln.getInitializer();
      bn.getVarTable().setParent(nametable);
      // need to check initialization node
      // checkLocationFromBlockNode(md, bn.getVarTable(), bn, constraint);
      for (int i = 0; i < bn.size(); i++) {
        BlockStatementNode bsn = bn.get(i);
        checkLocationFromBlockStatementNode(md, bn.getVarTable(), bsn, constraint);
      }

      // calculate glb location of condition and update statements
      CompositeLocation condLoc =
          checkLocationFromExpressionNode(md, bn.getVarTable(), ln.getCondition(),
              new CompositeLocation(), constraint, false);
      // addLocationType(ln.getCondition().getType(), condLoc);

      constraint = generateNewConstraint(constraint, condLoc);

      checkLocationFromBlockNode(md, bn.getVarTable(), ln.getUpdate(), constraint);
      checkLocationFromBlockNode(md, bn.getVarTable(), ln.getBody(), constraint);

      return new CompositeLocation();

    }

  }

  private CompositeLocation checkLocationFromSubBlockNode(MethodDescriptor md,
      SymbolTable nametable, SubBlockNode sbn, CompositeLocation constraint) {
    CompositeLocation compLoc =
        checkLocationFromBlockNode(md, nametable, sbn.getBlockNode(), constraint);
    return compLoc;
  }

  private CompositeLocation generateNewConstraint(CompositeLocation currentCon,
      CompositeLocation newCon) {

    if (currentCon == null) {
      return newCon;
    } else {
      // compute GLB of current constraint and new constraint
      Set<CompositeLocation> inputSet = new HashSet<CompositeLocation>();
      inputSet.add(currentCon);
      inputSet.add(newCon);
      return CompositeLattice.calculateGLB(inputSet, "");
    }

  }

  private CompositeLocation checkLocationFromIfStatementNode(MethodDescriptor md,
      SymbolTable nametable, IfStatementNode isn, CompositeLocation constraint) {

    System.out.println("\n\ncheckLocationFromIfStatementNode=" + isn.printNode(0));
    CompositeLocation condLoc =
        checkLocationFromExpressionNode(md, nametable, isn.getCondition(), new CompositeLocation(),
            constraint, false);

    System.out.println("-######old constraint=" + constraint);
    constraint = generateNewConstraint(constraint, condLoc);
    System.out.println("-######new constraint=" + constraint);
    checkLocationFromBlockNode(md, nametable, isn.getTrueBlock(), constraint);

    if (isn.getFalseBlock() != null) {
      checkLocationFromBlockNode(md, nametable, isn.getFalseBlock(), constraint);
    }

    return new CompositeLocation();
  }

  private void checkOwnership(MethodDescriptor md, TreeNode tn, ExpressionNode srcExpNode) {

    if (srcExpNode.kind() == Kind.NameNode || srcExpNode.kind() == Kind.FieldAccessNode) {
      if (srcExpNode.getType().isPtr() && !srcExpNode.getType().isNull()) {
        // first, check the linear type
        // RHS reference should be owned by the current method
        FieldDescriptor fd = getFieldDescriptorFromExpressionNode(srcExpNode);
        boolean isOwned;
        if (fd == null) {
          // local var case
          isOwned = ((SSJavaType) srcExpNode.getType().getExtension()).isOwned();
        } else {
          // field case
          isOwned = ssjava.isOwnedByMethod(md, fd);
        }
        if (!isOwned) {
          throw new Error(
              "It is not allowed to create the reference alias from the reference not owned by the method at "
                  + generateErrorMessage(md.getClassDesc(), tn));
        }

      }
    }

  }

  private CompositeLocation checkLocationFromDeclarationNode(MethodDescriptor md,
      SymbolTable nametable, DeclarationNode dn, CompositeLocation constraint) {

    VarDescriptor vd = dn.getVarDescriptor();

    CompositeLocation destLoc = d2loc.get(vd);

    if (dn.getExpression() != null) {

      checkOwnership(md, dn, dn.getExpression());

      CompositeLocation expressionLoc =
          checkLocationFromExpressionNode(md, nametable, dn.getExpression(),
              new CompositeLocation(), constraint, false);
      // addTypeLocation(dn.getExpression().getType(), expressionLoc);

      if (expressionLoc != null) {

        // checking location order
        if (!CompositeLattice.isGreaterThan(expressionLoc, destLoc,
            generateErrorMessage(md.getClassDesc(), dn))) {
          throw new Error("The value flow from " + expressionLoc + " to " + destLoc
              + " does not respect location hierarchy on the assignment " + dn.printNode(0)
              + " at " + md.getClassDesc().getSourceFileName() + "::" + dn.getNumLine());
        }
      }
      return expressionLoc;

    } else {

      return new CompositeLocation();

    }

  }

  private void checkDeclarationInSubBlockNode(MethodDescriptor md, SymbolTable nametable,
      SubBlockNode sbn) {
    checkDeclarationInBlockNode(md, nametable, sbn.getBlockNode());
  }

  private CompositeLocation checkLocationFromBlockExpressionNode(MethodDescriptor md,
      SymbolTable nametable, BlockExpressionNode ben, CompositeLocation constraint) {

    CompositeLocation compLoc =
        checkLocationFromExpressionNode(md, nametable, ben.getExpression(), null, constraint, false);
    // addTypeLocation(ben.getExpression().getType(), compLoc);
    return compLoc;
  }

  private CompositeLocation checkLocationFromExpressionNode(MethodDescriptor md,
      SymbolTable nametable, ExpressionNode en, CompositeLocation loc,
      CompositeLocation constraint, boolean isLHS) {

    CompositeLocation compLoc = null;
    switch (en.kind()) {

    case Kind.AssignmentNode:
      compLoc =
          checkLocationFromAssignmentNode(md, nametable, (AssignmentNode) en, loc, constraint);
      break;

    case Kind.FieldAccessNode:
      compLoc =
          checkLocationFromFieldAccessNode(md, nametable, (FieldAccessNode) en, loc, constraint);
      break;

    case Kind.NameNode:
      compLoc = checkLocationFromNameNode(md, nametable, (NameNode) en, loc, constraint);
      break;

    case Kind.OpNode:
      compLoc = checkLocationFromOpNode(md, nametable, (OpNode) en, constraint);
      break;

    case Kind.CreateObjectNode:
      compLoc = checkLocationFromCreateObjectNode(md, nametable, (CreateObjectNode) en);
      break;

    case Kind.ArrayAccessNode:
      compLoc =
          checkLocationFromArrayAccessNode(md, nametable, (ArrayAccessNode) en, constraint, isLHS);
      break;

    case Kind.LiteralNode:
      compLoc = checkLocationFromLiteralNode(md, nametable, (LiteralNode) en, loc);
      break;

    case Kind.MethodInvokeNode:
      compLoc =
          checkLocationFromMethodInvokeNode(md, nametable, (MethodInvokeNode) en, loc, constraint);
      break;

    case Kind.TertiaryNode:
      compLoc = checkLocationFromTertiaryNode(md, nametable, (TertiaryNode) en, constraint);
      break;

    case Kind.CastNode:
      compLoc = checkLocationFromCastNode(md, nametable, (CastNode) en, constraint);
      break;

    // case Kind.InstanceOfNode:
    // checkInstanceOfNode(md, nametable, (InstanceOfNode) en, td);
    // return null;

    // case Kind.ArrayInitializerNode:
    // checkArrayInitializerNode(md, nametable, (ArrayInitializerNode) en,
    // td);
    // return null;

    // case Kind.ClassTypeNode:
    // checkClassTypeNode(md, nametable, (ClassTypeNode) en, td);
    // return null;

    // case Kind.OffsetNode:
    // checkOffsetNode(md, nametable, (OffsetNode)en, td);
    // return null;

    default:
      return null;

    }
    // addTypeLocation(en.getType(), compLoc);
    return compLoc;

  }

  private CompositeLocation checkLocationFromCastNode(MethodDescriptor md, SymbolTable nametable,
      CastNode cn, CompositeLocation constraint) {

    ExpressionNode en = cn.getExpression();
    return checkLocationFromExpressionNode(md, nametable, en, new CompositeLocation(), constraint,
        false);

  }

  private CompositeLocation checkLocationFromTertiaryNode(MethodDescriptor md,
      SymbolTable nametable, TertiaryNode tn, CompositeLocation constraint) {
    ClassDescriptor cd = md.getClassDesc();

    CompositeLocation condLoc =
        checkLocationFromExpressionNode(md, nametable, tn.getCond(), new CompositeLocation(),
            constraint, false);
    // addLocationType(tn.getCond().getType(), condLoc);
    CompositeLocation trueLoc =
        checkLocationFromExpressionNode(md, nametable, tn.getTrueExpr(), new CompositeLocation(),
            constraint, false);
    // addLocationType(tn.getTrueExpr().getType(), trueLoc);
    CompositeLocation falseLoc =
        checkLocationFromExpressionNode(md, nametable, tn.getFalseExpr(), new CompositeLocation(),
            constraint, false);
    // addLocationType(tn.getFalseExpr().getType(), falseLoc);

    // locations from true/false branches can be TOP when there are only literal
    // values
    // in this case, we don't need to check flow down rule!

    // System.out.println("\n#tertiary cond=" + tn.getCond().printNode(0) +
    // " Loc=" + condLoc);
    // System.out.println("# true=" + tn.getTrueExpr().printNode(0) + " Loc=" +
    // trueLoc);
    // System.out.println("# false=" + tn.getFalseExpr().printNode(0) + " Loc="
    // + falseLoc);

    // we don't need to check that condLoc is higher than trueLoc & falseLoc
    // if (!trueLoc.get(0).isTop()
    // && !CompositeLattice.isGreaterThan(condLoc, trueLoc, generateErrorMessage(cd, tn))) {
    // throw new Error(
    // "The location of the condition expression is lower than the true expression at "
    // + cd.getSourceFileName() + ":" + tn.getCond().getNumLine());
    // }
    //
    // if (!falseLoc.get(0).isTop()
    // && !CompositeLattice.isGreaterThan(condLoc, falseLoc,
    // generateErrorMessage(cd, tn.getCond()))) {
    // throw new Error(
    // "The location of the condition expression is lower than the false expression at "
    // + cd.getSourceFileName() + ":" + tn.getCond().getNumLine());
    // }

    // then, return glb of trueLoc & falseLoc
    Set<CompositeLocation> glbInputSet = new HashSet<CompositeLocation>();
    glbInputSet.add(condLoc);
    glbInputSet.add(trueLoc);
    glbInputSet.add(falseLoc);

    if (glbInputSet.size() == 1) {
      return trueLoc;
    } else {
      return CompositeLattice.calculateGLB(glbInputSet, generateErrorMessage(cd, tn));
    }

  }

  private CompositeLocation checkLocationFromMethodInvokeNode(MethodDescriptor md,
      SymbolTable nametable, MethodInvokeNode min, CompositeLocation loc,
      CompositeLocation constraint) {

    ClassDescriptor cd = md.getClassDesc();
    MethodDescriptor calleeMethodDesc = min.getMethod();

    NameDescriptor baseName = min.getBaseName();
    boolean isSystemout = false;
    if (baseName != null) {
      isSystemout = baseName.getSymbol().equals("System.out");
    }

    if (!ssjava.isSSJavaUtil(calleeMethodDesc.getClassDesc())
        && !ssjava.isTrustMethod(calleeMethodDesc) && !calleeMethodDesc.getModifiers().isNative()
        && !isSystemout) {

      CompositeLocation baseLocation = null;
      if (min.getExpression() != null) {
        baseLocation =
            checkLocationFromExpressionNode(md, nametable, min.getExpression(),
                new CompositeLocation(), constraint, false);
      } else {
        if (min.getMethod().isStatic()) {
          String globalLocId = ssjava.getMethodLattice(md).getGlobalLoc();
          if (globalLocId == null) {
            throw new Error("Method lattice does not define global variable location at "
                + generateErrorMessage(md.getClassDesc(), min));
          }
          baseLocation = new CompositeLocation(new Location(md, globalLocId));
        } else {
          String thisLocId = ssjava.getMethodLattice(md).getThisLoc();
          baseLocation = new CompositeLocation(new Location(md, thisLocId));
        }
      }

      // System.out.println("\n#checkLocationFromMethodInvokeNode=" +
      // min.printNode(0)
      // + " baseLocation=" + baseLocation + " constraint=" + constraint);

      // setup the location list of caller's arguments
      List<CompositeLocation> callerArgList = new ArrayList<CompositeLocation>();

      // setup the location list of callee's parameters
      MethodLattice<String> calleeLattice = ssjava.getMethodLattice(calleeMethodDesc);
      List<CompositeLocation> calleeParamList = new ArrayList<CompositeLocation>();

      if (min.numArgs() > 0) {
        if (!calleeMethodDesc.isStatic()) {
          callerArgList.add(baseLocation);
        }
        for (int i = 0; i < min.numArgs(); i++) {
          ExpressionNode en = min.getArg(i);
          CompositeLocation callerArgLoc =
              checkLocationFromExpressionNode(md, nametable, en, new CompositeLocation(),
                  constraint, false);
          callerArgList.add(callerArgLoc);
        }

        if (!calleeMethodDesc.isStatic()) {
          CompositeLocation calleeThisLoc =
              new CompositeLocation(new Location(calleeMethodDesc, calleeLattice.getThisLoc()));
          calleeParamList.add(calleeThisLoc);
        }

        for (int i = 0; i < calleeMethodDesc.numParameters(); i++) {
          VarDescriptor calleevd = (VarDescriptor) calleeMethodDesc.getParameter(i);
          CompositeLocation calleeLoc = d2loc.get(calleevd);
          calleeParamList.add(calleeLoc);
        }
      }

      if (constraint != null) {
        // check whether the PC location is lower than one of the
        // argument locations. If it is lower, the callee has to have @PCLOC
        // annotation that declares the program counter that is higher than
        // corresponding parameter

        CompositeLocation calleePCLOC = ssjava.getPCLocation(calleeMethodDesc);

        for (int idx = 0; idx < callerArgList.size(); idx++) {
          CompositeLocation argLocation = callerArgList.get(idx);

          // if the PC location is lower than an argument location
          // then, need to check that the callee's the initial location for the PC is also lower
          // than the corresponding parameter location

          if (!argLocation.get(0).isTop()
              && CompositeLattice.compare(argLocation, constraint, true,
                  generateErrorMessage(cd, min)) == ComparisonResult.GREATER) {

            CompositeLocation paramLocation = calleeParamList.get(idx);

            int paramCompareResult =
                CompositeLattice.compare(paramLocation, calleePCLOC, true,
                    generateErrorMessage(cd, min));
            // CompositeLattice.compare(calleePCLOC, paramLocation, true,
            // generateErrorMessage(cd, min));

            System.out.println("-CHECKPCLOC:");
            System.out.println("---ARG LOC="
                + argLocation
                + " callerPCLOC="
                + constraint
                + " result="
                + CompositeLattice.compare(argLocation, constraint, true,
                    generateErrorMessage(cd, min)));
            System.out.println("---PARAM LOC=" + paramLocation + " calleePCLOC=" + calleePCLOC
                + " paramCompareResult=" + paramCompareResult);

            if (!(paramLocation.get(0).equals(calleePCLOC.get(0)) && calleePCLOC.getSize() > 1)
                && paramCompareResult == ComparisonResult.LESS) {
              throw new Error(
                  "The argument(idx="
                      + idx
                      + ") location "
                      + argLocation
                      + "is higher than the caller program counter location "
                      + constraint
                      + ". Need to specify that the initial PC location of the callee, which is currently set to "
                      + calleePCLOC + ", is not higher than " + paramLocation + " in the method "
                      + calleeMethodDesc.getSymbol() + ":" + min.getNumLine());
            }

          }

        }

      }

      checkCalleeConstraints(md, nametable, min, baseLocation, constraint);

      checkCallerArgumentLocationConstraints(md, nametable, min, baseLocation, constraint);

      if (!min.getMethod().getReturnType().isVoid()) {
        // If method has a return value, compute the highest possible return
        // location in the caller's perspective
        CompositeLocation ceilingLoc =
            computeCeilingLocationForCaller(md, nametable, min, baseLocation, constraint);

        if (ceilingLoc == null) {
          return new CompositeLocation(Location.createTopLocation(md));
        }
        return ceilingLoc;
      }
    }

    return new CompositeLocation(Location.createTopLocation(md));

  }

  private CompositeLocation translateCallerLocToCalleeLoc(MethodDescriptor calleeMD,
      CompositeLocation calleeBaseLoc, CompositeLocation constraint) {

    CompositeLocation calleeConstraint = new CompositeLocation();

    // if (constraint.startsWith(calleeBaseLoc)) {
    // if the first part of constraint loc is matched with callee base loc
    Location thisLoc = new Location(calleeMD, ssjava.getMethodLattice(calleeMD).getThisLoc());
    calleeConstraint.addLocation(thisLoc);
    for (int i = calleeBaseLoc.getSize(); i < constraint.getSize(); i++) {
      calleeConstraint.addLocation(constraint.get(i));
    }

    // }

    return calleeConstraint;
  }

  private void checkCallerArgumentLocationConstraints(MethodDescriptor md, SymbolTable nametable,
      MethodInvokeNode min, CompositeLocation callerBaseLoc, CompositeLocation constraint) {
    // if parameter location consists of THIS and FIELD location,
    // caller should pass an argument that is comparable to the declared
    // parameter location
    // and is not lower than the declared parameter location in the field
    // lattice.

    MethodDescriptor calleemd = min.getMethod();

    if (calleemd.isStatic()) {
      return;
    }

    List<CompositeLocation> callerArgList = new ArrayList<CompositeLocation>();
    List<CompositeLocation> calleeParamList = new ArrayList<CompositeLocation>();

    MethodLattice<String> calleeLattice = ssjava.getMethodLattice(calleemd);
    Location calleeThisLoc = new Location(calleemd, calleeLattice.getThisLoc());

    for (int i = 0; i < min.numArgs(); i++) {
      ExpressionNode en = min.getArg(i);
      CompositeLocation callerArgLoc =
          checkLocationFromExpressionNode(md, nametable, en, new CompositeLocation(), constraint,
              false);
      callerArgList.add(callerArgLoc);
    }

    // setup callee params set
    for (int i = 0; i < calleemd.numParameters(); i++) {
      VarDescriptor calleevd = (VarDescriptor) calleemd.getParameter(i);
      CompositeLocation calleeLoc = d2loc.get(calleevd);
      calleeParamList.add(calleeLoc);
    }

    String errorMsg = generateErrorMessage(md.getClassDesc(), min);

    // System.out.println("checkCallerArgumentLocationConstraints=" +
    // min.printNode(0));
    // System.out.println("base location=" + callerBaseLoc + " constraint=" +
    // constraint);

    System.out.println("calleeParamList=" + calleeParamList);
    int offset = 0;
    if (!md.isStatic()) {
      offset = 1;
    }
    for (int i = offset; i < calleeParamList.size(); i++) {
      CompositeLocation calleeParamLoc = calleeParamList.get(i);
      if (calleeParamLoc.get(0).equals(calleeThisLoc) && calleeParamLoc.getSize() > 1) {

        // callee parameter location has field information
        CompositeLocation callerArgLoc = callerArgList.get(i);

        CompositeLocation paramLocation =
            translateCalleeParamLocToCaller(md, calleeParamLoc, callerBaseLoc, errorMsg);

        Set<CompositeLocation> inputGLBSet = new HashSet<CompositeLocation>();
        if (constraint != null) {
          inputGLBSet.add(callerArgLoc);
          inputGLBSet.add(constraint);
          callerArgLoc =
              CompositeLattice.calculateGLB(inputGLBSet,
                  generateErrorMessage(md.getClassDesc(), min));
        }

        Location argLastLoc = callerArgLoc.get(callerArgLoc.getSize() - 1);
        Location paramLastLoc = paramLocation.get(paramLocation.getSize() - 1);

        if (argLastLoc.equals(paramLastLoc) && ssjava.isSharedLocation(argLastLoc)
            && ssjava.isSharedLocation(paramLastLoc)) {
          continue;
        }

        System.out.println("---idx=" + i + "  callerArgLoc=" + callerArgLoc + "   paramLocation="
            + paramLocation);
        // if (!CompositeLattice.isGreaterThan(callerArgLoc, paramLocation, errorMsg)) {
        if (CompositeLattice.compare(callerArgLoc, paramLocation, true, errorMsg) == ComparisonResult.LESS) {
          throw new Error("Caller argument '" + min.getArg(i).printNode(0) + " : " + callerArgLoc
              + "' should be higher than corresponding callee's parameter : " + paramLocation
              + " at " + errorMsg);
        }

      }
    }

  }

  private CompositeLocation translateCalleeParamLocToCaller(MethodDescriptor md,
      CompositeLocation calleeParamLoc, CompositeLocation callerBaseLocation, String errorMsg) {

    CompositeLocation translate = new CompositeLocation();

    for (int i = 0; i < callerBaseLocation.getSize(); i++) {
      translate.addLocation(callerBaseLocation.get(i));
    }

    for (int i = 1; i < calleeParamLoc.getSize(); i++) {
      translate.addLocation(calleeParamLoc.get(i));
    }

    // System.out.println("TRANSLATED=" + translate + " from calleeParamLoc=" +
    // calleeParamLoc);

    return translate;
  }

  private CompositeLocation computeCeilingLocationForCaller(MethodDescriptor md,
      SymbolTable nametable, MethodInvokeNode min, CompositeLocation baseLocation,
      CompositeLocation constraint) {
    List<CompositeLocation> argList = new ArrayList<CompositeLocation>();

    // by default, method has a THIS parameter
    if (!min.getMethod().isStatic()) {
      argList.add(baseLocation);
    }

    for (int i = 0; i < min.numArgs(); i++) {
      ExpressionNode en = min.getArg(i);
      CompositeLocation callerArg =
          checkLocationFromExpressionNode(md, nametable, en, new CompositeLocation(), constraint,
              false);
      argList.add(callerArg);
    }

    // System.out.println("\n## computeReturnLocation=" + min.getMethod() + " argList=" + argList);
    CompositeLocation ceilLoc = md2ReturnLocGen.get(min.getMethod()).computeReturnLocation(argList);
    // System.out.println("## ReturnLocation=" + ceilLoc);

    return ceilLoc;

  }

  private void checkCalleeConstraints(MethodDescriptor md, SymbolTable nametable,
      MethodInvokeNode min, CompositeLocation callerBaseLoc, CompositeLocation constraint) {

    MethodDescriptor calleemd = min.getMethod();

    MethodLattice<String> calleeLattice = ssjava.getMethodLattice(calleemd);

    System.out.println("checkCalleeConstraints=" + calleemd + " calleeLattice.getThisLoc()="
        + calleeLattice.getThisLoc());

    List<CompositeLocation> callerArgList = new ArrayList<CompositeLocation>();
    List<CompositeLocation> calleeParamList = new ArrayList<CompositeLocation>();

    if (min.numArgs() > 0) {
      // caller needs to guarantee that it passes arguments in regarding to
      // callee's hierarchy

      // setup caller args set
      // first, add caller's base(this) location
      if (!calleemd.isStatic())
        callerArgList.add(callerBaseLoc);
      // second, add caller's arguments
      for (int i = 0; i < min.numArgs(); i++) {
        ExpressionNode en = min.getArg(i);
        CompositeLocation callerArgLoc =
            checkLocationFromExpressionNode(md, nametable, en, new CompositeLocation(), constraint,
                false);
        callerArgList.add(callerArgLoc);
      }

      // setup callee params set
      // first, add callee's this location
      if (!calleemd.isStatic()) {
        CompositeLocation calleeThisLoc =
            new CompositeLocation(new Location(calleemd, calleeLattice.getThisLoc()));
        calleeParamList.add(calleeThisLoc);
      }
      // second, add callee's parameters
      for (int i = 0; i < calleemd.numParameters(); i++) {
        VarDescriptor calleevd = (VarDescriptor) calleemd.getParameter(i);
        CompositeLocation calleeLoc = d2loc.get(calleevd);
        // System.out.println("calleevd=" + calleevd + " loc=" + calleeLoc);
        calleeParamList.add(calleeLoc);
      }

      // here, check if ordering relations among caller's args respect
      // ordering relations in-between callee's args
      CHECK: for (int i = 0; i < calleeParamList.size(); i++) {
        CompositeLocation calleeLoc1 = calleeParamList.get(i);
        CompositeLocation callerLoc1 = callerArgList.get(i);

        for (int j = 0; j < calleeParamList.size(); j++) {
          if (i != j) {
            CompositeLocation calleeLoc2 = calleeParamList.get(j);
            CompositeLocation callerLoc2 = callerArgList.get(j);

            if (callerLoc1.get(callerLoc1.getSize() - 1).isTop()
                || callerLoc2.get(callerLoc2.getSize() - 1).isTop()) {
              continue CHECK;
            }

            // System.out.println("calleeLoc1=" + calleeLoc1);
            // System.out.println("calleeLoc2=" + calleeLoc2 +
            // "calleeParamList=" + calleeParamList);

            int callerResult =
                CompositeLattice.compare(callerLoc1, callerLoc2, true,
                    generateErrorMessage(md.getClassDesc(), min));
            // System.out.println("callerResult=" + callerResult);
            int calleeResult =
                CompositeLattice.compare(calleeLoc1, calleeLoc2, true,
                    generateErrorMessage(md.getClassDesc(), min));
            // System.out.println("calleeResult=" + calleeResult);

            if (callerResult == ComparisonResult.EQUAL) {
              if (ssjava.isSharedLocation(callerLoc1.get(callerLoc1.getSize() - 1))
                  && ssjava.isSharedLocation(callerLoc2.get(callerLoc2.getSize() - 1))) {
                // if both of them are shared locations, promote them to
                // "GREATER relation"
                callerResult = ComparisonResult.GREATER;
              }
            }

            if (calleeResult == ComparisonResult.GREATER
                && callerResult != ComparisonResult.GREATER) {
              // If calleeLoc1 is higher than calleeLoc2
              // then, caller should have same ordering relation in-bet
              // callerLoc1 & callerLoc2

              String paramName1, paramName2;

              if (!calleemd.isStatic()) {
                if (i == 0) {
                  paramName1 = "'THIS'";
                } else {
                  paramName1 = "'parameter " + calleemd.getParamName(i - 1) + "'";
                }
              } else {
                paramName1 = "'parameter " + calleemd.getParamName(i) + "'";
              }

              if (!calleemd.isStatic()) {
                if (j == 0 && !calleemd.isStatic()) {
                  paramName2 = "'THIS'";
                } else {
                  paramName2 = "'parameter " + calleemd.getParamName(j - 1) + "'";
                }
              } else {
                paramName2 = "'parameter " + calleemd.getParamName(j) + "'";
              }

              throw new Error(
                  "Caller doesn't respect an ordering relation among method arguments: callee expects that "
                      + paramName1 + " should be higher than " + paramName2 + " in " + calleemd
                      + " at " + md.getClassDesc().getSourceFileName() + ":" + min.getNumLine());
            }
          }

        }
      }

    }

  }

  private CompositeLocation checkLocationFromArrayAccessNode(MethodDescriptor md,
      SymbolTable nametable, ArrayAccessNode aan, CompositeLocation constraint, boolean isLHS) {
    System.out.println("aan=" + aan.printNode(0) + "  line#=" + aan.getNumLine());
    ClassDescriptor cd = md.getClassDesc();
    System.out.println("aan.getExpression()=" + aan.getExpression().getClass());
    CompositeLocation arrayLoc =
        checkLocationFromExpressionNode(md, nametable, aan.getExpression(),
            new CompositeLocation(), constraint, isLHS);
    System.out.println("HERE?");
    // addTypeLocation(aan.getExpression().getType(), arrayLoc);
    CompositeLocation indexLoc =
        checkLocationFromExpressionNode(md, nametable, aan.getIndex(), new CompositeLocation(),
            constraint, isLHS);
    // addTypeLocation(aan.getIndex().getType(), indexLoc);
    System.out.println("HERE2?");

    if (isLHS) {
      if (!CompositeLattice.isGreaterThan(indexLoc, arrayLoc, generateErrorMessage(cd, aan))) {
        throw new Error("Array index value is not higher than array location at "
            + generateErrorMessage(cd, aan));
      }
      return arrayLoc;
    } else {
      Set<CompositeLocation> inputGLB = new HashSet<CompositeLocation>();
      inputGLB.add(arrayLoc);
      inputGLB.add(indexLoc);
      System.out.println("arrayLoc=" + arrayLoc + "   indexLoc=" + indexLoc);
      CompositeLocation comp =
          CompositeLattice.calculateGLB(inputGLB, generateErrorMessage(cd, aan));
      System.out.println("---aan=" + aan.printNode(0) + "  compLoc=" + comp);
      return comp;
    }

  }

  private CompositeLocation checkLocationFromCreateObjectNode(MethodDescriptor md,
      SymbolTable nametable, CreateObjectNode con) {

    ClassDescriptor cd = md.getClassDesc();

    CompositeLocation compLoc = new CompositeLocation();
    compLoc.addLocation(Location.createTopLocation(md));
    return compLoc;

  }

  private CompositeLocation checkLocationFromOpNode(MethodDescriptor md, SymbolTable nametable,
      OpNode on, CompositeLocation constraint) {

    ClassDescriptor cd = md.getClassDesc();
    CompositeLocation leftLoc = new CompositeLocation();
    leftLoc =
        checkLocationFromExpressionNode(md, nametable, on.getLeft(), leftLoc, constraint, false);
    // addTypeLocation(on.getLeft().getType(), leftLoc);

    CompositeLocation rightLoc = new CompositeLocation();
    if (on.getRight() != null) {
      rightLoc =
          checkLocationFromExpressionNode(md, nametable, on.getRight(), rightLoc, constraint, false);
      // addTypeLocation(on.getRight().getType(), rightLoc);
    }

    // System.out.println("# left loc=" + leftLoc + " from " + on.getLeft().getClass());
    // if (on.getRight() != null) {
    // System.out.println("# right loc=" + rightLoc + " from " + on.getRight().getClass());
    // }

    Operation op = on.getOp();

    switch (op.getOp()) {

    case Operation.UNARYPLUS:
    case Operation.UNARYMINUS:
    case Operation.LOGIC_NOT:
      // single operand
      return leftLoc;

    case Operation.LOGIC_OR:
    case Operation.LOGIC_AND:
    case Operation.COMP:
    case Operation.BIT_OR:
    case Operation.BIT_XOR:
    case Operation.BIT_AND:
    case Operation.ISAVAILABLE:
    case Operation.EQUAL:
    case Operation.NOTEQUAL:
    case Operation.LT:
    case Operation.GT:
    case Operation.LTE:
    case Operation.GTE:
    case Operation.ADD:
    case Operation.SUB:
    case Operation.MULT:
    case Operation.DIV:
    case Operation.MOD:
    case Operation.LEFTSHIFT:
    case Operation.RIGHTSHIFT:
    case Operation.URIGHTSHIFT:

      Set<CompositeLocation> inputSet = new HashSet<CompositeLocation>();
      inputSet.add(leftLoc);
      inputSet.add(rightLoc);
      CompositeLocation glbCompLoc =
          CompositeLattice.calculateGLB(inputSet, generateErrorMessage(cd, on));
      return glbCompLoc;

    default:
      throw new Error(op.toString());
    }

  }

  private CompositeLocation checkLocationFromLiteralNode(MethodDescriptor md,
      SymbolTable nametable, LiteralNode en, CompositeLocation loc) {

    // literal value has the top location so that value can be flowed into any
    // location
    Location literalLoc = Location.createTopLocation(md);
    loc.addLocation(literalLoc);
    return loc;

  }

  private CompositeLocation checkLocationFromNameNode(MethodDescriptor md, SymbolTable nametable,
      NameNode nn, CompositeLocation loc, CompositeLocation constraint) {

    // System.out.println("checkLocationFromNameNode nn=" + nn.printNode(0));
    NameDescriptor nd = nn.getName();
    if (nd.getBase() != null) {
      loc =
          checkLocationFromExpressionNode(md, nametable, nn.getExpression(), loc, constraint, false);
    } else {
      String varname = nd.toString();
      if (varname.equals("this")) {
        // 'this' itself!
        MethodLattice<String> methodLattice = ssjava.getMethodLattice(md);
        String thisLocId = methodLattice.getThisLoc();
        if (thisLocId == null) {
          throw new Error("The location for 'this' is not defined at "
              + md.getClassDesc().getSourceFileName() + "::" + nn.getNumLine());
        }
        Location locElement = new Location(md, thisLocId);
        loc.addLocation(locElement);
        return loc;

      }

      Descriptor d = (Descriptor) nametable.get(varname);

      // CompositeLocation localLoc = null;
      if (d instanceof VarDescriptor) {
        VarDescriptor vd = (VarDescriptor) d;
        // localLoc = d2loc.get(vd);
        // the type of var descriptor has a composite location!
        loc = ((SSJavaType) vd.getType().getExtension()).getCompLoc().clone();
      } else if (d instanceof FieldDescriptor) {
        // the type of field descriptor has a location!
        FieldDescriptor fd = (FieldDescriptor) d;
        // System.out.println("fd=" + fd);
        if (fd.isStatic()) {
          if (fd.isFinal()) {
            // if it is 'static final', the location has TOP since no one can
            // change its value
            loc.addLocation(Location.createTopLocation(md));
            return loc;
          } else {

            // if 'static', the location has pre-assigned global loc
            MethodLattice<String> localLattice = ssjava.getMethodLattice(md);
            String globalLocId = localLattice.getGlobalLoc();
            if (globalLocId == null) {
              throw new Error("Global location element is not defined in the method " + md);
            }
            Location globalLoc = new Location(md, globalLocId);
            System.out.println("static=" + globalLoc);
            loc.addLocation(globalLoc);
          }
        } else {
          // the location of field access starts from this, followed by field
          // location
          MethodLattice<String> localLattice = ssjava.getMethodLattice(md);
          Location thisLoc = new Location(md, localLattice.getThisLoc());
          loc.addLocation(thisLoc);
        }

        Location fieldLoc = (Location) fd.getType().getExtension();
        loc.addLocation(fieldLoc);
      } else if (d == null) {
        // access static field
        FieldDescriptor fd = nn.getField();

        MethodLattice<String> localLattice = ssjava.getMethodLattice(md);
        String globalLocId = localLattice.getGlobalLoc();
        if (globalLocId == null) {
          throw new Error("Method lattice does not define global variable location at "
              + generateErrorMessage(md.getClassDesc(), nn));
        }
        loc.addLocation(new Location(md, globalLocId));

        Location fieldLoc = (Location) fd.getType().getExtension();
        loc.addLocation(fieldLoc);

        return loc;

      }
    }

    return loc;
  }

  private CompositeLocation checkLocationFromFieldAccessNode(MethodDescriptor md,
      SymbolTable nametable, FieldAccessNode fan, CompositeLocation loc,
      CompositeLocation constraint) {

    ExpressionNode left = fan.getExpression();
    TypeDescriptor ltd = left.getType();

    FieldDescriptor fd = fan.getField();

    String varName = null;
    if (left.kind() == Kind.NameNode) {
      NameDescriptor nd = ((NameNode) left).getName();
      varName = nd.toString();
    }

    if (ltd.isClassNameRef() || (varName != null && varName.equals("this"))) {
      // using a class name directly or access using this
      if (fd.isStatic() && fd.isFinal()) {
        loc.addLocation(Location.createTopLocation(md));
        return loc;
      }
    }

    Set<CompositeLocation> inputGLB = new HashSet<CompositeLocation>();
    if (left instanceof ArrayAccessNode) {
      ArrayAccessNode aan = (ArrayAccessNode) left;
      CompositeLocation indexLoc =
          checkLocationFromExpressionNode(md, nametable, aan.getIndex(), loc, constraint, false);
      inputGLB.add(indexLoc);
    }

    loc = checkLocationFromExpressionNode(md, nametable, left, loc, constraint, false);

    if (!left.getType().isPrimitive()) {

      if (!fd.getSymbol().equals("length")) {
        // array.length access, return the location of the array
        Location fieldLoc = getFieldLocation(fd);
        loc.addLocation(fieldLoc);
      }

    }

    inputGLB.add(loc);
    loc = CompositeLattice.calculateGLB(inputGLB, generateErrorMessage(md.getClassDesc(), fan));

    return loc;
  }

  private Location getFieldLocation(FieldDescriptor fd) {

    // System.out.println("### getFieldLocation=" + fd);
    // System.out.println("### fd.getType().getExtension()=" +
    // fd.getType().getExtension());

    Location fieldLoc = (Location) fd.getType().getExtension();

    // handle the case that method annotation checking skips checking field
    // declaration
    if (fieldLoc == null) {
      fieldLoc = checkFieldDeclaration(fd.getClassDescriptor(), fd);
    }

    return fieldLoc;

  }

  private FieldDescriptor getFieldDescriptorFromExpressionNode(ExpressionNode en) {

    if (en.kind() == Kind.NameNode) {
      NameNode nn = (NameNode) en;
      if (nn.getField() != null) {
        return nn.getField();
      }

      if (nn.getName() != null && nn.getName().getBase() != null) {
        return getFieldDescriptorFromExpressionNode(nn.getExpression());
      }

    } else if (en.kind() == Kind.FieldAccessNode) {
      FieldAccessNode fan = (FieldAccessNode) en;
      return fan.getField();
    }

    return null;
  }

  private CompositeLocation checkLocationFromAssignmentNode(MethodDescriptor md,
      SymbolTable nametable, AssignmentNode an, CompositeLocation loc, CompositeLocation constraint) {

    System.out.println("\n\ncheckLocationFromAssignmentNode=" + an.printNode(0));

    ClassDescriptor cd = md.getClassDesc();

    Set<CompositeLocation> inputGLBSet = new HashSet<CompositeLocation>();

    boolean postinc = true;
    if (an.getOperation().getBaseOp() == null
        || (an.getOperation().getBaseOp().getOp() != Operation.POSTINC && an.getOperation()
            .getBaseOp().getOp() != Operation.POSTDEC))
      postinc = false;

    // if LHS is array access node, need to check if array index is higher
    // than array itself
    CompositeLocation destLocation =
        checkLocationFromExpressionNode(md, nametable, an.getDest(), new CompositeLocation(),
            constraint, true);

    CompositeLocation rhsLocation;
    CompositeLocation srcLocation;

    if (!postinc) {

      checkOwnership(md, an, an.getSrc());

      rhsLocation =
          checkLocationFromExpressionNode(md, nametable, an.getSrc(), new CompositeLocation(),
              constraint, false);

      if (an.getOperation().getOp() >= 2 && an.getOperation().getOp() <= 12) {
        // if assignment contains OP+EQ operator, need to merge location types
        // of LHS & RHS into the RHS
        Set<CompositeLocation> srcGLBSet = new HashSet<CompositeLocation>();
        srcGLBSet.add(rhsLocation);
        srcGLBSet.add(destLocation);
        srcLocation = CompositeLattice.calculateGLB(srcGLBSet, generateErrorMessage(cd, an));
      } else {
        srcLocation = rhsLocation;
      }

      if (constraint != null) {

        if (!CompositeLattice.isGreaterThan(constraint, destLocation, generateErrorMessage(cd, an))) {
          throw new Error("The value flow from " + constraint + " to " + destLocation
              + " does not respect location hierarchy on the assignment " + an.printNode(0)
              + " at " + cd.getSourceFileName() + "::" + an.getNumLine());
        }
        // inputGLBSet.add(srcLocation);
        // inputGLBSet.add(constraint);
        // srcLocation = CompositeLattice.calculateGLB(inputGLBSet,
        // generateErrorMessage(cd, an));
      }

      System.out.println("src=" + srcLocation + "  dest=" + destLocation + "  const=" + constraint);

      if (!CompositeLattice.isGreaterThan(srcLocation, destLocation, generateErrorMessage(cd, an))) {

        String context = "";
        if (constraint != null) {
          context = " and the current context constraint is " + constraint;
        }

        throw new Error("The value flow from " + srcLocation + " to " + destLocation
            + " does not respect location hierarchy on the assignment " + an.printNode(0) + context
            + " at " + cd.getSourceFileName() + "::" + an.getNumLine());
      }

      if (srcLocation.equals(destLocation)) {
        // keep it for definitely written analysis
        Set<FlatNode> flatNodeSet = ssjava.getBuildFlat().getFlatNodeSet(an);
        for (Iterator iterator = flatNodeSet.iterator(); iterator.hasNext();) {
          FlatNode fn = (FlatNode) iterator.next();
          ssjava.addSameHeightWriteFlatNode(fn);
        }

      } 

    } else {
      destLocation =
          rhsLocation =
              checkLocationFromExpressionNode(md, nametable, an.getDest(), new CompositeLocation(),
                  constraint, false);

      if (constraint != null) {

        if (!CompositeLattice.isGreaterThan(constraint, destLocation, generateErrorMessage(cd, an))) {
          throw new Error("The value flow from " + constraint + " to " + destLocation
              + " does not respect location hierarchy on the assignment " + an.printNode(0)
              + " at " + cd.getSourceFileName() + "::" + an.getNumLine());
        }
        // inputGLBSet.add(rhsLocation);
        // inputGLBSet.add(constraint);
        // srcLocation = CompositeLattice.calculateGLB(inputGLBSet,
        // generateErrorMessage(cd, an));
        srcLocation = rhsLocation;
      } else {
        srcLocation = rhsLocation;
      }

      if (!CompositeLattice.isGreaterThan(srcLocation, destLocation, generateErrorMessage(cd, an))) {

        if (srcLocation.equals(destLocation)) {
          throw new Error("Location " + srcLocation
              + " is not allowed to have the value flow that moves within the same location at '"
              + an.printNode(0) + "' of " + cd.getSourceFileName() + "::" + an.getNumLine());
        } else {
          throw new Error("The value flow from " + srcLocation + " to " + destLocation
              + " does not respect location hierarchy on the assignment " + an.printNode(0)
              + " at " + cd.getSourceFileName() + "::" + an.getNumLine());
        }

      }

      if (srcLocation.equals(destLocation)) {
        // keep it for definitely written analysis
        Set<FlatNode> flatNodeSet = ssjava.getBuildFlat().getFlatNodeSet(an);
        for (Iterator iterator = flatNodeSet.iterator(); iterator.hasNext();) {
          FlatNode fn = (FlatNode) iterator.next();
          ssjava.addSameHeightWriteFlatNode(fn);
        }
      }

    }

    return destLocation;
  }

  private void assignLocationOfVarDescriptor(VarDescriptor vd, MethodDescriptor md,
      SymbolTable nametable, TreeNode n) {

    ClassDescriptor cd = md.getClassDesc();
    Vector<AnnotationDescriptor> annotationVec = vd.getType().getAnnotationMarkers();

    // currently enforce every variable to have corresponding location
    if (annotationVec.size() == 0) {
      throw new Error("Location is not assigned to variable '" + vd.getSymbol()
          + "' in the method '" + md + "' of the class " + cd.getSymbol() + " at "
          + generateErrorMessage(cd, n));
    }

    int locDecCount = 0;
    for (int i = 0; i < annotationVec.size(); i++) {
      AnnotationDescriptor ad = annotationVec.elementAt(i);

      if (ad.getType() == AnnotationDescriptor.SINGLE_ANNOTATION) {

        if (ad.getMarker().equals(SSJavaAnalysis.LOC)) {
          locDecCount++;
          if (locDecCount > 1) {// variable can have at most one location
            throw new Error(vd.getSymbol() + " has more than one location declaration.");
          }
          String locDec = ad.getValue(); // check if location is defined

          if (locDec.startsWith(SSJavaAnalysis.DELTA)) {
            DeltaLocation deltaLoc = parseDeltaDeclaration(md, n, locDec);
            d2loc.put(vd, deltaLoc);
            addLocationType(vd.getType(), deltaLoc);
          } else {
            CompositeLocation compLoc = parseLocationDeclaration(md, n, locDec);

            Location lastElement = compLoc.get(compLoc.getSize() - 1);
            if (ssjava.isSharedLocation(lastElement)) {
              ssjava.mapSharedLocation2Descriptor(lastElement, vd);
            }

            d2loc.put(vd, compLoc);
            addLocationType(vd.getType(), compLoc);
          }

        }
      }
    }

  }

  private DeltaLocation parseDeltaDeclaration(MethodDescriptor md, TreeNode n, String locDec) {

    int deltaCount = 0;
    int dIdx = locDec.indexOf(SSJavaAnalysis.DELTA);
    while (dIdx >= 0) {
      deltaCount++;
      int beginIdx = dIdx + 6;
      locDec = locDec.substring(beginIdx, locDec.length() - 1);
      dIdx = locDec.indexOf(SSJavaAnalysis.DELTA);
    }

    CompositeLocation compLoc = parseLocationDeclaration(md, n, locDec);
    DeltaLocation deltaLoc = new DeltaLocation(compLoc, deltaCount);

    return deltaLoc;
  }

  private Location parseFieldLocDeclaraton(String decl, String msg) throws Exception {

    int idx = decl.indexOf(".");

    String className = decl.substring(0, idx);
    String fieldName = decl.substring(idx + 1);

    className.replaceAll(" ", "");
    fieldName.replaceAll(" ", "");

    Descriptor d = state.getClassSymbolTable().get(className);

    if (d == null) {
      // System.out.println("state.getClassSymbolTable()=" +
      // state.getClassSymbolTable());
      throw new Error("The class in the location declaration '" + decl + "' does not exist at "
          + msg);
    }

    assert (d instanceof ClassDescriptor);
    SSJavaLattice<String> lattice = ssjava.getClassLattice((ClassDescriptor) d);
    if (!lattice.containsKey(fieldName)) {
      throw new Error("The location " + fieldName + " is not defined in the field lattice of '"
          + className + "' at " + msg);
    }

    return new Location(d, fieldName);
  }

  private CompositeLocation parseLocationDeclaration(MethodDescriptor md, TreeNode n, String locDec) {

    CompositeLocation compLoc = new CompositeLocation();

    StringTokenizer tokenizer = new StringTokenizer(locDec, ",");
    List<String> locIdList = new ArrayList<String>();
    while (tokenizer.hasMoreTokens()) {
      String locId = tokenizer.nextToken();
      locIdList.add(locId);
    }

    // at least,one location element needs to be here!
    assert (locIdList.size() > 0);

    // assume that loc with idx 0 comes from the local lattice
    // loc with idx 1 comes from the field lattice

    String localLocId = locIdList.get(0);
    SSJavaLattice<String> localLattice = CompositeLattice.getLatticeByDescriptor(md);
    Location localLoc = new Location(md, localLocId);
    if (localLattice == null || (!localLattice.containsKey(localLocId))) {
      throw new Error("Location " + localLocId
          + " is not defined in the local variable lattice at "
          + md.getClassDesc().getSourceFileName() + "::" + (n != null ? n.getNumLine() : md) + ".");
    }
    compLoc.addLocation(localLoc);

    for (int i = 1; i < locIdList.size(); i++) {
      String locName = locIdList.get(i);
      try {
        Location fieldLoc =
            parseFieldLocDeclaraton(locName, generateErrorMessage(md.getClassDesc(), n));
        compLoc.addLocation(fieldLoc);
      } catch (Exception e) {
        throw new Error("The location declaration '" + locName + "' is wrong  at "
            + generateErrorMessage(md.getClassDesc(), n));
      }
    }

    return compLoc;

  }

  private void checkDeclarationNode(MethodDescriptor md, SymbolTable nametable, DeclarationNode dn) {
    VarDescriptor vd = dn.getVarDescriptor();
    assignLocationOfVarDescriptor(vd, md, nametable, dn);
  }

  private void checkDeclarationInClass(ClassDescriptor cd) {
    // Check to see that fields are okay
    for (Iterator field_it = cd.getFields(); field_it.hasNext();) {
      FieldDescriptor fd = (FieldDescriptor) field_it.next();

      if (!(fd.isFinal() && fd.isStatic())) {
        checkFieldDeclaration(cd, fd);
      } else {
        // for static final, assign top location by default
        Location loc = Location.createTopLocation(cd);
        addLocationType(fd.getType(), loc);
      }
    }
  }

  private Location checkFieldDeclaration(ClassDescriptor cd, FieldDescriptor fd) {

    Vector<AnnotationDescriptor> annotationVec = fd.getType().getAnnotationMarkers();

    // currently enforce every field to have corresponding location
    if (annotationVec.size() == 0) {
      throw new Error("Location is not assigned to the field '" + fd.getSymbol()
          + "' of the class " + cd.getSymbol() + " at " + cd.getSourceFileName());
    }

    if (annotationVec.size() > 1) {
      // variable can have at most one location
      throw new Error("Field " + fd.getSymbol() + " of class " + cd
          + " has more than one location.");
    }

    AnnotationDescriptor ad = annotationVec.elementAt(0);
    Location loc = null;

    if (ad.getType() == AnnotationDescriptor.SINGLE_ANNOTATION) {
      if (ad.getMarker().equals(SSJavaAnalysis.LOC)) {
        String locationID = ad.getValue();
        // check if location is defined
        SSJavaLattice<String> lattice = ssjava.getClassLattice(cd);
        if (lattice == null || (!lattice.containsKey(locationID))) {
          throw new Error("Location " + locationID
              + " is not defined in the field lattice of class " + cd.getSymbol() + " at"
              + cd.getSourceFileName() + ".");
        }
        loc = new Location(cd, locationID);

        if (ssjava.isSharedLocation(loc)) {
          ssjava.mapSharedLocation2Descriptor(loc, fd);
        }

        addLocationType(fd.getType(), loc);

        if (ssjava.isSharedLocation(loc)) {
          ssjava.addSharedDesc(loc, fd);
        }
      }
    }

    return loc;
  }

  private void addLocationType(TypeDescriptor type, CompositeLocation loc) {
    if (type != null) {
      TypeExtension te = type.getExtension();
      SSJavaType ssType;
      if (te != null) {
        ssType = (SSJavaType) te;
        ssType.setCompLoc(loc);
      } else {
        ssType = new SSJavaType(loc);
        type.setExtension(ssType);
      }
    }
  }

  private void addLocationType(TypeDescriptor type, Location loc) {
    if (type != null) {
      type.setExtension(loc);
    }
  }

  static class CompositeLattice {

    public static boolean isGreaterThan(CompositeLocation loc1, CompositeLocation loc2, String msg) {

      // System.out.println("\nisGreaterThan=" + loc1 + " " + loc2 + " msg=" +
      // msg);
      int baseCompareResult = compareBaseLocationSet(loc1, loc2, true, false, msg);
      if (baseCompareResult == ComparisonResult.EQUAL) {
        if (compareDelta(loc1, loc2) == ComparisonResult.GREATER) {
          return true;
        } else {
          return false;
        }
      } else if (baseCompareResult == ComparisonResult.GREATER) {
        return true;
      } else {
        return false;
      }

    }

    public static int compare(CompositeLocation loc1, CompositeLocation loc2, boolean ignore,
        String msg) {

      // System.out.println("compare=" + loc1 + " " + loc2);
      int baseCompareResult = compareBaseLocationSet(loc1, loc2, false, ignore, msg);

      if (baseCompareResult == ComparisonResult.EQUAL) {
        return compareDelta(loc1, loc2);
      } else {
        return baseCompareResult;
      }

    }

    private static int compareDelta(CompositeLocation dLoc1, CompositeLocation dLoc2) {

      int deltaCount1 = 0;
      int deltaCount2 = 0;
      if (dLoc1 instanceof DeltaLocation) {
        deltaCount1 = ((DeltaLocation) dLoc1).getNumDelta();
      }

      if (dLoc2 instanceof DeltaLocation) {
        deltaCount2 = ((DeltaLocation) dLoc2).getNumDelta();
      }
      if (deltaCount1 < deltaCount2) {
        return ComparisonResult.GREATER;
      } else if (deltaCount1 == deltaCount2) {
        return ComparisonResult.EQUAL;
      } else {
        return ComparisonResult.LESS;
      }

    }

    private static int compareBaseLocationSet(CompositeLocation compLoc1,
        CompositeLocation compLoc2, boolean awareSharedLoc, boolean ignore, String msg) {

      // if compLoc1 is greater than compLoc2, return true
      // else return false;

      // compare one by one in according to the order of the tuple
      int numOfTie = 0;
      for (int i = 0; i < compLoc1.getSize(); i++) {
        Location loc1 = compLoc1.get(i);
        if (i >= compLoc2.getSize()) {
          if (ignore) {
            return ComparisonResult.INCOMPARABLE;
          } else {
            throw new Error("Failed to compare two locations of " + compLoc1 + " and " + compLoc2
                + " because they are not comparable at " + msg);
          }
        }
        Location loc2 = compLoc2.get(i);

        Descriptor descriptor = getCommonParentDescriptor(loc1, loc2, msg);
        SSJavaLattice<String> lattice = getLatticeByDescriptor(descriptor);

        // check if the shared location is appeared only at the end of the
        // composite location
        if (lattice.getSharedLocSet().contains(loc1.getLocIdentifier())) {
          if (i != (compLoc1.getSize() - 1)) {
            throw new Error("The shared location " + loc1.getLocIdentifier()
                + " cannot be appeared in the middle of composite location at" + msg);
          }
        }

        if (lattice.getSharedLocSet().contains(loc2.getLocIdentifier())) {
          if (i != (compLoc2.getSize() - 1)) {
            throw new Error("The shared location " + loc2.getLocIdentifier()
                + " cannot be appeared in the middle of composite location at " + msg);
          }
        }

        // if (!lattice1.equals(lattice2)) {
        // throw new Error("Failed to compare two locations of " + compLoc1 +
        // " and " + compLoc2
        // + " because they are not comparable at " + msg);
        // }

        if (loc1.getLocIdentifier().equals(loc2.getLocIdentifier())) {
          numOfTie++;
          // check if the current location is the spinning location
          // note that the spinning location only can be appeared in the last
          // part of the composite location
          if (awareSharedLoc && numOfTie == compLoc1.getSize()
              && lattice.getSharedLocSet().contains(loc1.getLocIdentifier())) {
            return ComparisonResult.GREATER;
          }
          continue;
        } else if (lattice.isGreaterThan(loc1.getLocIdentifier(), loc2.getLocIdentifier())) {
          return ComparisonResult.GREATER;
        } else {
          if (lattice.isComparable(loc1.getLocIdentifier(), loc2.getLocIdentifier())) {
            return ComparisonResult.LESS;
          } else {
            return ComparisonResult.INCOMPARABLE;
          }
        }

      }

      if (numOfTie == compLoc1.getSize()) {

        if (numOfTie != compLoc2.getSize()) {

          if (ignore) {
            return ComparisonResult.INCOMPARABLE;
          } else {
            throw new Error("Failed to compare two locations of " + compLoc1 + " and " + compLoc2
                + " because they are not comparable at " + msg);
          }

        }

        return ComparisonResult.EQUAL;
      }

      return ComparisonResult.LESS;

    }

    public static CompositeLocation calculateGLB(Set<CompositeLocation> inputSet, String errMsg) {

      System.out.println("Calculating GLB=" + inputSet);
      CompositeLocation glbCompLoc = new CompositeLocation();

      // calculate GLB of the first(priority) element
      Set<String> priorityLocIdentifierSet = new HashSet<String>();
      Descriptor priorityDescriptor = null;

      Hashtable<String, Set<CompositeLocation>> locId2CompLocSet =
          new Hashtable<String, Set<CompositeLocation>>();
      // mapping from the priority loc ID to its full representation by the
      // composite location

      int maxTupleSize = 0;
      int minTupleSize = 0;
      CompositeLocation maxCompLoc = null;

      Location prevPriorityLoc = null;
      for (Iterator iterator = inputSet.iterator(); iterator.hasNext();) {
        CompositeLocation compLoc = (CompositeLocation) iterator.next();
        if (compLoc.getSize() > maxTupleSize) {
          maxTupleSize = compLoc.getSize();
          maxCompLoc = compLoc;
        }
        if (minTupleSize == 0 || compLoc.getSize() < minTupleSize) {
          minTupleSize = compLoc.getSize();
        }
        Location priorityLoc = compLoc.get(0);
        String priorityLocId = priorityLoc.getLocIdentifier();
        priorityLocIdentifierSet.add(priorityLocId);

        if (locId2CompLocSet.containsKey(priorityLocId)) {
          locId2CompLocSet.get(priorityLocId).add(compLoc);
        } else {
          Set<CompositeLocation> newSet = new HashSet<CompositeLocation>();
          newSet.add(compLoc);
          locId2CompLocSet.put(priorityLocId, newSet);
        }

        // check if priority location are coming from the same lattice
        if (priorityDescriptor == null) {
          priorityDescriptor = priorityLoc.getDescriptor();
        } else {
          priorityDescriptor = getCommonParentDescriptor(priorityLoc, prevPriorityLoc, errMsg);
        }
        prevPriorityLoc = priorityLoc;
        // else if (!priorityDescriptor.equals(priorityLoc.getDescriptor())) {
        // throw new Error("Failed to calculate GLB of " + inputSet
        // + " because they are from different lattices.");
        // }
      }

      SSJavaLattice<String> locOrder = getLatticeByDescriptor(priorityDescriptor);
      String glbOfPriorityLoc = locOrder.getGLB(priorityLocIdentifierSet);
      glbCompLoc.addLocation(new Location(priorityDescriptor, glbOfPriorityLoc));
      Set<CompositeLocation> compSet = locId2CompLocSet.get(glbOfPriorityLoc);

      if (compSet == null) {
        // when GLB(x1,x2)!=x1 and !=x2 : GLB case 4
        // mean that the result is already lower than <x1,y1> and <x2,y2>
        // assign TOP to the rest of the location elements

        // in this case, do not take care about delta
        // CompositeLocation inputComp = inputSet.iterator().next();
        // for (int i = 1; i < maxTupleSize; i++) {
        for (int i = 1; i < minTupleSize; i++) {
          glbCompLoc.addLocation(Location.createTopLocation(maxCompLoc.get(i).getDescriptor()));
        }
      } else {

        // here find out composite location that has a maximum length tuple
        // if we have three input set: [A], [A,B], [A,B,C]
        // maximum length tuple will be [A,B,C]
        int max = 0;
        CompositeLocation maxFromCompSet = null;
        for (Iterator iterator = compSet.iterator(); iterator.hasNext();) {
          CompositeLocation c = (CompositeLocation) iterator.next();
          if (c.getSize() > max) {
            max = c.getSize();
            maxFromCompSet = c;
          }
        }

        if (compSet.size() == 1) {
          // if GLB(x1,x2)==x1 or x2 : GLB case 2,3
          CompositeLocation comp = compSet.iterator().next();
          for (int i = 1; i < comp.getSize(); i++) {
            glbCompLoc.addLocation(comp.get(i));
          }

          // if input location corresponding to glb is a delta, need to apply
          // delta to glb result
          if (comp instanceof DeltaLocation) {
            glbCompLoc = new DeltaLocation(glbCompLoc, 1);
          }

        } else {
          // when GLB(x1,x2)==x1 and x2 : GLB case 1
          // if more than one location shares the same priority GLB
          // need to calculate the rest of GLB loc

          // setup input set starting from the second tuple item
          Set<CompositeLocation> innerGLBInput = new HashSet<CompositeLocation>();
          for (Iterator iterator = compSet.iterator(); iterator.hasNext();) {
            CompositeLocation compLoc = (CompositeLocation) iterator.next();
            CompositeLocation innerCompLoc = new CompositeLocation();
            for (int idx = 1; idx < compLoc.getSize(); idx++) {
              innerCompLoc.addLocation(compLoc.get(idx));
            }
            if (innerCompLoc.getSize() > 0) {
              innerGLBInput.add(innerCompLoc);
            }
          }

          if (innerGLBInput.size() > 0) {
            // System.out.println("######innerGLBInput=" + innerGLBInput);
            CompositeLocation innerGLB = CompositeLattice.calculateGLB(innerGLBInput, errMsg);
            for (int idx = 0; idx < innerGLB.getSize(); idx++) {
              glbCompLoc.addLocation(innerGLB.get(idx));
            }
          }

          // if input location corresponding to glb is a delta, need to apply
          // delta to glb result

          for (Iterator iterator = compSet.iterator(); iterator.hasNext();) {
            CompositeLocation compLoc = (CompositeLocation) iterator.next();
            if (compLoc instanceof DeltaLocation) {
              if (glbCompLoc.equals(compLoc)) {
                glbCompLoc = new DeltaLocation(glbCompLoc, 1);
                break;
              }
            }
          }

        }
      }

      System.out.println("GLB=" + glbCompLoc);
      return glbCompLoc;

    }

    static SSJavaLattice<String> getLatticeByDescriptor(Descriptor d) {

      SSJavaLattice<String> lattice = null;

      if (d instanceof ClassDescriptor) {
        lattice = ssjava.getCd2lattice().get(d);
      } else if (d instanceof MethodDescriptor) {
        if (ssjava.getMd2lattice().containsKey(d)) {
          lattice = ssjava.getMd2lattice().get(d);
        } else {
          // use default lattice for the method
          lattice = ssjava.getCd2methodDefault().get(((MethodDescriptor) d).getClassDesc());
        }
      }

      return lattice;
    }

    static Descriptor getCommonParentDescriptor(Location loc1, Location loc2, String msg) {

      Descriptor d1 = loc1.getDescriptor();
      Descriptor d2 = loc2.getDescriptor();

      Descriptor descriptor;

      if (d1 instanceof ClassDescriptor && d2 instanceof ClassDescriptor) {

        if (d1.equals(d2)) {
          descriptor = d1;
        } else {
          // identifying which one is parent class
          Set<Descriptor> d1SubClassesSet = ssjava.tu.getSubClasses((ClassDescriptor) d1);
          Set<Descriptor> d2SubClassesSet = ssjava.tu.getSubClasses((ClassDescriptor) d2);

          if (d1 == null && d2 == null) {
            throw new Error("Failed to compare two locations of " + loc1 + " and " + loc2
                + " because they are not comparable at " + msg);
          } else if (d1SubClassesSet != null && d1SubClassesSet.contains(d2)) {
            descriptor = d1;
          } else if (d2SubClassesSet != null && d2SubClassesSet.contains(d1)) {
            descriptor = d2;
          } else {
            throw new Error("Failed to compare two locations of " + loc1 + " and " + loc2
                + " because they are not comparable at " + msg);
          }
        }

      } else if (d1 instanceof MethodDescriptor && d2 instanceof MethodDescriptor) {

        if (d1.equals(d2)) {
          descriptor = d1;
        } else {

          // identifying which one is parent class
          MethodDescriptor md1 = (MethodDescriptor) d1;
          MethodDescriptor md2 = (MethodDescriptor) d2;

          if (!md1.matches(md2)) {
            throw new Error("Failed to compare two locations of " + loc1 + " and " + loc2
                + " because they are not comparable at " + msg);
          }

          Set<Descriptor> d1SubClassesSet =
              ssjava.tu.getSubClasses(((MethodDescriptor) d1).getClassDesc());
          Set<Descriptor> d2SubClassesSet =
              ssjava.tu.getSubClasses(((MethodDescriptor) d2).getClassDesc());

          if (d1 == null && d2 == null) {
            throw new Error("Failed to compare two locations of " + loc1 + " and " + loc2
                + " because they are not comparable at " + msg);
          } else if (d1 != null && d1SubClassesSet.contains(d2)) {
            descriptor = d1;
          } else if (d2 != null && d2SubClassesSet.contains(d1)) {
            descriptor = d2;
          } else {
            throw new Error("Failed to compare two locations of " + loc1 + " and " + loc2
                + " because they are not comparable at " + msg);
          }
        }

      } else {
        throw new Error("Failed to compare two locations of " + loc1 + " and " + loc2
            + " because they are not comparable at " + msg);
      }

      return descriptor;

    }

  }

  class ComparisonResult {

    public static final int GREATER = 0;
    public static final int EQUAL = 1;
    public static final int LESS = 2;
    public static final int INCOMPARABLE = 3;
    int result;

  }

}

class ReturnLocGenerator {

  public static final int PARAMISHIGHER = 0;
  public static final int PARAMISSAME = 1;
  public static final int IGNORE = 2;

  private Hashtable<Integer, Integer> paramIdx2paramType;

  private CompositeLocation declaredReturnLoc = null;

  public ReturnLocGenerator(CompositeLocation returnLoc, MethodDescriptor md,
      List<CompositeLocation> params, String msg) {

    CompositeLocation thisLoc = params.get(0);
    if (returnLoc.get(0).equals(thisLoc.get(0)) && returnLoc.getSize() > 1) {
      // if the declared return location consists of THIS and field location,
      // return location for the caller's side has to have same field element
      this.declaredReturnLoc = returnLoc;
    } else {
      // creating mappings
      paramIdx2paramType = new Hashtable<Integer, Integer>();
      for (int i = 0; i < params.size(); i++) {
        CompositeLocation param = params.get(i);
        int compareResult = CompositeLattice.compare(param, returnLoc, true, msg);

        int type;
        if (compareResult == ComparisonResult.GREATER) {
          type = 0;
        } else if (compareResult == ComparisonResult.EQUAL) {
          type = 1;
        } else {
          type = 2;
        }
        paramIdx2paramType.put(new Integer(i), new Integer(type));
      }
    }

  }

  public CompositeLocation computeReturnLocation(List<CompositeLocation> args) {

    if (declaredReturnLoc != null) {
      // when developer specify that the return value is [THIS,field]
      // needs to translate to the caller's location
      CompositeLocation callerLoc = new CompositeLocation();
      CompositeLocation callerBaseLocation = args.get(0);

      for (int i = 0; i < callerBaseLocation.getSize(); i++) {
        callerLoc.addLocation(callerBaseLocation.get(i));
      }
      for (int i = 1; i < declaredReturnLoc.getSize(); i++) {
        callerLoc.addLocation(declaredReturnLoc.get(i));
      }
      return callerLoc;
    } else {
      // compute the highest possible location in caller's side
      assert paramIdx2paramType.keySet().size() == args.size();

      Set<CompositeLocation> inputGLB = new HashSet<CompositeLocation>();
      for (int i = 0; i < args.size(); i++) {
        int type = (paramIdx2paramType.get(new Integer(i))).intValue();
        CompositeLocation argLoc = args.get(i);
        if (type == PARAMISHIGHER || type == PARAMISSAME) {
          // return loc is equal to or lower than param
          inputGLB.add(argLoc);
        }
      }

      // compute GLB of arguments subset that are same or higher than return
      // location
      if (inputGLB.isEmpty()) {
        if (args.size() == 0) {
          return null;
        }
        CompositeLocation rtr =
            new CompositeLocation(Location.createTopLocation(args.get(0).get(0).getDescriptor()));
        return rtr;
      } else {
        CompositeLocation glb = CompositeLattice.calculateGLB(inputGLB, "");
        return glb;
      }
    }

  }
}