Robust/src/Analysis/SSJava/DefinitelyWrittenCheck.java

   1 package Analysis.SSJava;
   2
   3 import java.util.Enumeration;
   4 import java.util.HashSet;
   5 import java.util.Hashtable;
   6 import java.util.Iterator;
   7 import java.util.LinkedList;
   8 import java.util.Set;
   9 import java.util.Stack;
  10
  11 import Analysis.CallGraph.CallGraph;
  12 import Analysis.Loops.LoopFinder;
  13 import IR.Descriptor;
  14 import IR.FieldDescriptor;
  15 import IR.MethodDescriptor;
  16 import IR.Operation;
  17 import IR.State;
  18 import IR.TypeDescriptor;
  19 import IR.TypeExtension;
  20 import IR.Flat.FKind;
  21 import IR.Flat.FlatCall;
  22 import IR.Flat.FlatElementNode;
  23 import IR.Flat.FlatFieldNode;
  24 import IR.Flat.FlatLiteralNode;
  25 import IR.Flat.FlatMethod;
  26 import IR.Flat.FlatNew;
  27 import IR.Flat.FlatNode;
  28 import IR.Flat.FlatOpNode;
  29 import IR.Flat.FlatSetElementNode;
  30 import IR.Flat.FlatSetFieldNode;
  31 import IR.Flat.TempDescriptor;
  32 import IR.Tree.Modifiers;
  33
  34 public class DefinitelyWrittenCheck {
  35
  36   SSJavaAnalysis ssjava;
  37   State state;
  38   CallGraph callGraph;
  39
  40   int debugcount = 0;
  41
  42   // maps a descriptor to its known dependents: namely
  43   // methods or tasks that call the descriptor's method
  44   // AND are part of this analysis (reachable from main)
  45   private Hashtable<Descriptor, Set<MethodDescriptor>> mapDescriptorToSetDependents;
  46
  47   // maps a flat node to its WrittenSet: this keeps all heap path overwritten
  48   // previously.
  49   private Hashtable<FlatNode, Set<NTuple<Descriptor>>> mapFlatNodeToMustWriteSet;
  50
  51   // maps a temp descriptor to its heap path
  52   // each temp descriptor has a unique heap path since we do not allow any
  53   // alias.
  54   private Hashtable<Descriptor, NTuple<Descriptor>> mapHeapPath;
  55
  56   // maps a temp descriptor to its composite location
  57   private Hashtable<TempDescriptor, NTuple<Location>> mapDescriptorToLocationPath;
  58
  59   // maps a flat method to the READ that is the set of heap path that is
  60   // expected to be written before method invocation
  61   private Hashtable<FlatMethod, Set<NTuple<Descriptor>>> mapFlatMethodToReadSet;
  62
  63   // maps a flat method to the must-write set that is the set of heap path that
  64   // is overwritten on every possible path during method invocation
  65   private Hashtable<FlatMethod, Set<NTuple<Descriptor>>> mapFlatMethodToMustWriteSet;
  66
  67   // maps a flat method to the DELETE SET that is a set of heap path to shared
  68   // locations that are
  69   // written to but not overwritten by the higher value
  70   private Hashtable<FlatMethod, SharedLocMap> mapFlatMethodToDeleteSet;
  71
  72   // maps a flat method to the S SET that is a set of heap path to shared
  73   // locations that are overwritten by the higher value
  74   private Hashtable<FlatMethod, SharedLocMap> mapFlatMethodToSharedLocMap;
  75
  76   // maps a flat method to the may-wirte set that is the set of heap path that
  77   // might be written to
  78   private Hashtable<FlatMethod, Set<NTuple<Descriptor>>> mapFlatMethodToMayWriteSet;
  79
  80   // maps a call site to the read set contributed by all callees
  81   private Hashtable<FlatNode, Set<NTuple<Descriptor>>> mapFlatNodeToBoundReadSet;
  82
  83   // maps a call site to the must write set contributed by all callees
  84   private Hashtable<FlatNode, Set<NTuple<Descriptor>>> mapFlatNodeToBoundMustWriteSet;
  85
  86   // maps a call site to the may read set contributed by all callees
  87   private Hashtable<FlatNode, Set<NTuple<Descriptor>>> mapFlatNodeToBoundMayWriteSet;
  88
  89   // points to method containing SSJAVA Loop
  90   private MethodDescriptor methodContainingSSJavaLoop;
  91
  92   // maps a flatnode to definitely written analysis mapping M
  93   private Hashtable<FlatNode, Hashtable<NTuple<Descriptor>, Set<WriteAge>>> mapFlatNodetoEventLoopMap;
  94
  95   // maps shared location to the set of descriptors which belong to the shared
  96   // location
  97
  98   // keep current descriptors to visit in fixed-point interprocedural analysis,
  99   private Stack<MethodDescriptor> methodDescriptorsToVisitStack;
 100
 101   // when analyzing flatcall, need to re-schedule set of callee
 102   private Set<MethodDescriptor> calleesToEnqueue;
 103
 104   private Set<ReadSummary> possibleCalleeReadSummarySetToCaller;
 105
 106   public static final String arrayElementFieldName = "___element_";
 107   static protected Hashtable<TypeDescriptor, FieldDescriptor> mapTypeToArrayField;
 108
 109   // maps a method descriptor to the merged incoming caller's current
 110   // reading status
 111   // it is for setting clearance flag when all read set is overwritten
 112   private Hashtable<MethodDescriptor, ReadSummary> mapMethodDescriptorToReadSummary;
 113
 114   private Hashtable<MethodDescriptor, MultiSourceMap<NTuple<Location>, NTuple<Descriptor>>> mapMethodToSharedLocCoverSet;
 115
 116   private Hashtable<FlatNode, SharedLocMap> mapFlatNodeToSharedLocMapping;
 117   private Hashtable<FlatNode, SharedLocMap> mapFlatNodeToDeleteSet;
 118
 119   private Hashtable<Location, Set<Descriptor>> mapSharedLocationToCoverSet;
 120
 121   private LinkedList<MethodDescriptor> sortedDescriptors;
 122
 123   private LoopFinder ssjavaLoop;
 124   private Set<FlatNode> loopIncElements;
 125
 126   private Set<NTuple<Descriptor>> calleeUnionBoundReadSet;
 127   private Set<NTuple<Descriptor>> calleeIntersectBoundMustWriteSet;
 128   private Set<NTuple<Descriptor>> calleeUnionBoundMayWriteSet;
 129   private SharedLocMap calleeUnionBoundDeleteSet;
 130   private SharedLocMap calleeIntersectBoundSharedSet;
 131
 132   private Hashtable<Descriptor, Location> mapDescToLocation;
 133
 134   private TempDescriptor LOCAL;
 135
 136   public static int MAXAGE = 1;
 137
 138   public DefinitelyWrittenCheck(SSJavaAnalysis ssjava, State state) {
 139     this.state = state;
 140     this.ssjava = ssjava;
 141     this.callGraph = ssjava.getCallGraph();
 142     this.mapFlatNodeToMustWriteSet = new Hashtable<FlatNode, Set<NTuple<Descriptor>>>();
 143     this.mapDescriptorToSetDependents = new Hashtable<Descriptor, Set<MethodDescriptor>>();
 144     this.mapHeapPath = new Hashtable<Descriptor, NTuple<Descriptor>>();
 145     this.mapDescriptorToLocationPath = new Hashtable<TempDescriptor, NTuple<Location>>();
 146     this.mapFlatMethodToReadSet = new Hashtable<FlatMethod, Set<NTuple<Descriptor>>>();
 147     this.mapFlatMethodToMustWriteSet = new Hashtable<FlatMethod, Set<NTuple<Descriptor>>>();
 148     this.mapFlatMethodToMayWriteSet = new Hashtable<FlatMethod, Set<NTuple<Descriptor>>>();
 149     this.mapFlatNodetoEventLoopMap =
 150         new Hashtable<FlatNode, Hashtable<NTuple<Descriptor>, Set<WriteAge>>>();
 151     this.calleeUnionBoundReadSet = new HashSet<NTuple<Descriptor>>();
 152     this.calleeIntersectBoundMustWriteSet = new HashSet<NTuple<Descriptor>>();
 153     this.calleeUnionBoundMayWriteSet = new HashSet<NTuple<Descriptor>>();
 154
 155     this.methodDescriptorsToVisitStack = new Stack<MethodDescriptor>();
 156     this.calleesToEnqueue = new HashSet<MethodDescriptor>();
 157     this.mapTypeToArrayField = new Hashtable<TypeDescriptor, FieldDescriptor>();
 158     this.LOCAL = new TempDescriptor("LOCAL");
 159     this.mapDescToLocation = new Hashtable<Descriptor, Location>();
 160     this.possibleCalleeReadSummarySetToCaller = new HashSet<ReadSummary>();
 161     this.mapMethodDescriptorToReadSummary = new Hashtable<MethodDescriptor, ReadSummary>();
 162     this.mapFlatNodeToBoundReadSet = new Hashtable<FlatNode, Set<NTuple<Descriptor>>>();
 163     this.mapFlatNodeToBoundMustWriteSet = new Hashtable<FlatNode, Set<NTuple<Descriptor>>>();
 164     this.mapFlatNodeToBoundMayWriteSet = new Hashtable<FlatNode, Set<NTuple<Descriptor>>>();
 165     this.mapSharedLocationToCoverSet = new Hashtable<Location, Set<Descriptor>>();
 166     this.mapFlatNodeToSharedLocMapping = new Hashtable<FlatNode, SharedLocMap>();
 167     this.mapFlatMethodToDeleteSet = new Hashtable<FlatMethod, SharedLocMap>();
 168     this.calleeUnionBoundDeleteSet = new SharedLocMap();
 169     this.calleeIntersectBoundSharedSet = new SharedLocMap();
 170     this.mapFlatMethodToSharedLocMap = new Hashtable<FlatMethod, SharedLocMap>();
 171     this.mapMethodToSharedLocCoverSet =
 172         new Hashtable<MethodDescriptor, MultiSourceMap<NTuple<Location>, NTuple<Descriptor>>>();
 173     this.mapFlatNodeToDeleteSet = new Hashtable<FlatNode, SharedLocMap>();
 174   }
 175
 176   public void definitelyWrittenCheck() {
 177     if (!ssjava.getAnnotationRequireSet().isEmpty()) {
 178       initialize();
 179
 180       methodReadWriteSetAnalysis();
 181       computeSharedCoverSet();
 182
 183       sharedLocAnalysis();
 184
 185       eventLoopAnalysis();
 186
 187     }
 188   }
 189
 190   private void sharedLocAnalysis() {
 191
 192     // perform method READ/OVERWRITE analysis
 193     LinkedList<MethodDescriptor> descriptorListToAnalyze =
 194         (LinkedList<MethodDescriptor>) sortedDescriptors.clone();
 195
 196     // current descriptors to visit in fixed-point interprocedural analysis,
 197     // prioritized by
 198     // dependency in the call graph
 199     methodDescriptorsToVisitStack.clear();
 200
 201     descriptorListToAnalyze.removeFirst();
 202
 203     Set<MethodDescriptor> methodDescriptorToVistSet = new HashSet<MethodDescriptor>();
 204     methodDescriptorToVistSet.addAll(descriptorListToAnalyze);
 205
 206     while (!descriptorListToAnalyze.isEmpty()) {
 207       MethodDescriptor md = descriptorListToAnalyze.removeFirst();
 208       methodDescriptorsToVisitStack.add(md);
 209     }
 210
 211     // analyze scheduled methods until there are no more to visit
 212     while (!methodDescriptorsToVisitStack.isEmpty()) {
 213       // start to analyze leaf node
 214       MethodDescriptor md = methodDescriptorsToVisitStack.pop();
 215       FlatMethod fm = state.getMethodFlat(md);
 216
 217       SharedLocMap sharedLocMap = new SharedLocMap();
 218       SharedLocMap deleteSet = new SharedLocMap();
 219
 220       sharedLoc_analyzeMethod(fm, sharedLocMap, deleteSet);
 221       SharedLocMap prevSharedLocMap = mapFlatMethodToSharedLocMap.get(fm);
 222       SharedLocMap prevDeleteSet = mapFlatMethodToDeleteSet.get(fm);
 223
 224       if (!(deleteSet.equals(prevDeleteSet) && sharedLocMap.equals(prevSharedLocMap))) {
 225         mapFlatMethodToSharedLocMap.put(fm, sharedLocMap);
 226         mapFlatMethodToDeleteSet.put(fm, deleteSet);
 227
 228         // results for callee changed, so enqueue dependents caller for
 229         // further
 230         // analysis
 231         Iterator<MethodDescriptor> depsItr = getDependents(md).iterator();
 232         while (depsItr.hasNext()) {
 233           MethodDescriptor methodNext = depsItr.next();
 234           if (!methodDescriptorsToVisitStack.contains(methodNext)
 235               && methodDescriptorToVistSet.contains(methodNext)) {
 236             methodDescriptorsToVisitStack.add(methodNext);
 237           }
 238
 239         }
 240
 241       }
 242
 243     }
 244
 245     sharedLoc_analyzeEventLoop();
 246
 247   }
 248
 249   private void sharedLoc_analyzeEventLoop() {
 250     if (state.SSJAVADEBUG) {
 251       System.out.println("SSJAVA: Definite clearance for shared locations Analyzing: eventloop");
 252     }
 253     SharedLocMap sharedLocMap = new SharedLocMap();
 254     SharedLocMap deleteSet = new SharedLocMap();
 255     sharedLoc_analyzeBody(state.getMethodFlat(methodContainingSSJavaLoop),
 256         ssjava.getSSJavaLoopEntrance(), sharedLocMap, deleteSet, true);
 257
 258   }
 259
 260   private void sharedLoc_analyzeMethod(FlatMethod fm, SharedLocMap sharedLocMap,
 261       SharedLocMap deleteSet) {
 262     if (state.SSJAVADEBUG) {
 263       System.out.println("SSJAVA: Definite clearance for shared locations Analyzing: " + fm);
 264     }
 265
 266     sharedLoc_analyzeBody(fm, fm, sharedLocMap, deleteSet, false);
 267
 268   }
 269
 270   private void sharedLoc_analyzeBody(FlatMethod fm, FlatNode startNode, SharedLocMap sharedLocMap,
 271       SharedLocMap deleteSet, boolean isEventLoopBody) {
 272
 273     // intraprocedural analysis
 274     Set<FlatNode> flatNodesToVisit = new HashSet<FlatNode>();
 275     flatNodesToVisit.add(startNode);
 276
 277     while (!flatNodesToVisit.isEmpty()) {
 278       FlatNode fn = flatNodesToVisit.iterator().next();
 279       flatNodesToVisit.remove(fn);
 280
 281       SharedLocMap currSharedSet = new SharedLocMap();
 282       SharedLocMap currDeleteSet = new SharedLocMap();
 283
 284       for (int i = 0; i < fn.numPrev(); i++) {
 285         FlatNode prevFn = fn.getPrev(i);
 286         SharedLocMap inSharedLoc = mapFlatNodeToSharedLocMapping.get(prevFn);
 287         if (inSharedLoc != null) {
 288           mergeSharedLocMap(currSharedSet, inSharedLoc);
 289         }
 290
 291         SharedLocMap inDeleteLoc = mapFlatNodeToDeleteSet.get(prevFn);
 292         if (inDeleteLoc != null) {
 293           mergeDeleteSet(currDeleteSet, inDeleteLoc);
 294         }
 295       }
 296
 297       sharedLoc_nodeActions(fm, fn, currSharedSet, currDeleteSet, sharedLocMap, deleteSet,
 298           isEventLoopBody);
 299
 300       SharedLocMap prevSharedSet = mapFlatNodeToSharedLocMapping.get(fn);
 301       SharedLocMap prevDeleteSet = mapFlatNodeToDeleteSet.get(fn);
 302
 303       if (!(currSharedSet.equals(prevSharedSet) && currDeleteSet.equals(prevDeleteSet))) {
 304         mapFlatNodeToSharedLocMapping.put(fn, currSharedSet);
 305         mapFlatNodeToDeleteSet.put(fn, currDeleteSet);
 306         for (int i = 0; i < fn.numNext(); i++) {
 307           FlatNode nn = fn.getNext(i);
 308           if ((!isEventLoopBody) || loopIncElements.contains(nn)) {
 309             flatNodesToVisit.add(nn);
 310           }
 311
 312         }
 313       }
 314
 315     }
 316
 317   }
 318
 319   private void sharedLoc_nodeActions(FlatMethod fm, FlatNode fn, SharedLocMap curr,
 320       SharedLocMap currDeleteSet, SharedLocMap sharedLocMap, SharedLocMap deleteSet,
 321       boolean isEventLoopBody) {
 322
 323     MethodDescriptor md = fm.getMethod();
 324
 325     SharedLocMap killSet = new SharedLocMap();
 326     SharedLocMap genSet = new SharedLocMap();
 327
 328     TempDescriptor lhs;
 329     TempDescriptor rhs;
 330     FieldDescriptor fld;
 331
 332     switch (fn.kind()) {
 333
 334     case FKind.FlatOpNode: {
 335
 336       if (isEventLoopBody) {
 337         FlatOpNode fon = (FlatOpNode) fn;
 338
 339         if (fon.getOp().getOp() == Operation.ASSIGN) {
 340           lhs = fon.getDest();
 341           rhs = fon.getLeft();
 342
 343           if (!lhs.getSymbol().startsWith("neverused") && !lhs.getSymbol().startsWith("leftop")
 344               && !lhs.getSymbol().startsWith("rightop") && rhs.getType().isImmutable()) {
 345
 346             Location dstLoc = getLocation(lhs);
 347             if (dstLoc != null && ssjava.isSharedLocation(dstLoc)) {
 348               NTuple<Descriptor> lhsHeapPath = computePath(lhs);
 349               NTuple<Location> lhsLocTuple = mapDescriptorToLocationPath.get(lhs);
 350
 351               Location srcLoc = getLocation(lhs);
 352
 353               // computing gen/kill set
 354               computeKILLSetForWrite(curr, killSet, lhsLocTuple, lhsHeapPath);
 355               if (!dstLoc.equals(srcLoc)) {
 356                 computeGENSetForHigherWrite(curr, killSet, lhsLocTuple, lhsHeapPath);
 357                 updateDeleteSetForHigherWrite(currDeleteSet, lhsLocTuple, lhsHeapPath);
 358               } else {
 359                 computeGENSetForSameHeightWrite(curr, killSet, lhsLocTuple, lhsHeapPath);
 360                 updateDeleteSetForSameHeightWrite(currDeleteSet, lhsLocTuple, lhsHeapPath);
 361               }
 362
 363               // System.out.println("VAR WRITE:" + fn);
 364               // System.out.println("lhsLocTuple=" + lhsLocTuple +
 365               // " lhsHeapPath=" + lhsHeapPath);
 366               // System.out.println("dstLoc=" + dstLoc + " srcLoc=" + srcLoc);
 367               // System.out.println("KILLSET=" + killSet);
 368               // System.out.println("GENSet=" + genSet);
 369               // System.out.println("DELETESET=" + currDeleteSet);
 370
 371             }
 372
 373           }
 374
 375         }
 376
 377       }
 378
 379     }
 380       break;
 381
 382     case FKind.FlatSetFieldNode:
 383     case FKind.FlatSetElementNode: {
 384
 385       Location fieldLoc;
 386       if (fn.kind() == FKind.FlatSetFieldNode) {
 387         FlatSetFieldNode fsfn = (FlatSetFieldNode) fn;
 388         lhs = fsfn.getDst();
 389         fld = fsfn.getField();
 390         rhs = fsfn.getSrc();
 391         fieldLoc = (Location) fld.getType().getExtension();
 392       } else {
 393         FlatSetElementNode fsen = (FlatSetElementNode) fn;
 394         lhs = fsen.getDst();
 395         rhs = fsen.getSrc();
 396         TypeDescriptor td = lhs.getType().dereference();
 397         fld = getArrayField(td);
 398
 399         NTuple<Location> locTuple = deriveLocationTuple(md, lhs);
 400         fieldLoc = locTuple.get(locTuple.size() - 1);
 401       }
 402
 403       if (!isEventLoopBody && fieldLoc.getDescriptor().equals(md)) {
 404         // if the field belongs to the local lattice, no reason to calculate
 405         // shared location
 406         break;
 407       }
 408
 409       NTuple<Location> fieldLocTuple = new NTuple<Location>();
 410       if (fld.isStatic()) {
 411         if (fld.isFinal()) {
 412           // in this case, fld has TOP location
 413           Location topLocation = Location.createTopLocation(md);
 414           fieldLocTuple.add(topLocation);
 415         } else {
 416           fieldLocTuple.addAll(deriveGlobalLocationTuple(md));
 417           if (fn.kind() == FKind.FlatSetFieldNode) {
 418             fieldLocTuple.add((Location) fld.getType().getExtension());
 419           }
 420         }
 421
 422       } else {
 423         fieldLocTuple.addAll(deriveLocationTuple(md, lhs));
 424         if (fn.kind() == FKind.FlatSetFieldNode) {
 425           fieldLocTuple.add((Location) fld.getType().getExtension());
 426         }
 427       }
 428
 429       // shared loc extension
 430       Location srcLoc = getLocation(rhs);
 431       if (ssjava.isSharedLocation(fieldLoc)) {
 432         // only care the case that loc(f) is shared location
 433         // write(field)
 434
 435         // NTuple<Location> fieldLocTuple = new NTuple<Location>();
 436         // fieldLocTuple.addAll(mapDescriptorToLocationPath.get(lhs));
 437         // fieldLocTuple.add(fieldLoc);
 438
 439         NTuple<Descriptor> fldHeapPath = new NTuple<Descriptor>();
 440         fldHeapPath.addAll(computePath(lhs));
 441         fldHeapPath.add(fld);
 442
 443         // computing gen/kill set
 444         computeKILLSetForWrite(curr, killSet, fieldLocTuple, fldHeapPath);
 445         if (!fieldLoc.equals(srcLoc)) {
 446           computeGENSetForHigherWrite(curr, genSet, fieldLocTuple, fldHeapPath);
 447           updateDeleteSetForHigherWrite(currDeleteSet, fieldLocTuple, fldHeapPath);
 448         } else {
 449           computeGENSetForSameHeightWrite(curr, genSet, fieldLocTuple, fldHeapPath);
 450           updateDeleteSetForSameHeightWrite(currDeleteSet, fieldLocTuple, fldHeapPath);
 451         }
 452
 453         // System.out.println("################");
 454         // System.out.println("FIELD WRITE:" + fn);
 455         // System.out.println("FldHeapPath=" + fldHeapPath);
 456         // System.out.println("fieldLocTuple=" + fieldLocTuple + " srcLoc=" +
 457         // srcLoc);
 458         // System.out.println("KILLSET=" + killSet);
 459         // System.out.println("GENSet=" + genSet);
 460         // System.out.println("DELETESET=" + currDeleteSet);
 461       }
 462
 463     }
 464       break;
 465
 466     case FKind.FlatCall: {
 467       FlatCall fc = (FlatCall) fn;
 468
 469       if (ssjava.needTobeAnnotated(fc.getMethod())) {
 470
 471         bindHeapPathCallerArgWithCaleeParamForSharedLoc(fm.getMethod(), fc);
 472
 473         // computing gen/kill set
 474         generateKILLSetForFlatCall(curr, killSet);
 475         generateGENSetForFlatCall(curr, genSet);
 476
 477       }
 478 //      System.out.println("#FLATCALL=" + fc);
 479 //      System.out.println("KILLSET=" + killSet);
 480 //      System.out.println("GENSet=" + genSet);
 481 //      System.out.println("bound DELETE Set=" + calleeUnionBoundDeleteSet);
 482
 483     }
 484       break;
 485
 486     case FKind.FlatExit: {
 487       // merge the current delete/shared loc mapping
 488       mergeSharedLocMap(sharedLocMap, curr);
 489       mergeDeleteSet(deleteSet, currDeleteSet);
 490
 491       // System.out.println("#FLATEXIT sharedLocMap=" + sharedLocMap);
 492     }
 493       break;
 494
 495     }
 496
 497     computeNewMapping(curr, killSet, genSet);
 498     if (!curr.map.isEmpty()) {
 499 //      System.out.println(fn + "#######" + curr);
 500     }
 501
 502   }
 503
 504   private void generateGENSetForFlatCall(SharedLocMap curr, SharedLocMap genSet) {
 505
 506     Set<NTuple<Location>> locTupleSet = calleeIntersectBoundSharedSet.keySet();
 507     for (Iterator iterator = locTupleSet.iterator(); iterator.hasNext();) {
 508       NTuple<Location> locTupleKey = (NTuple<Location>) iterator.next();
 509       genSet.addWrite(locTupleKey, curr.get(locTupleKey));
 510       genSet.addWrite(locTupleKey, calleeIntersectBoundSharedSet.get(locTupleKey));
 511
 512       genSet.removeWriteAll(locTupleKey, calleeUnionBoundDeleteSet.get(locTupleKey));
 513     }
 514
 515   }
 516
 517   private void generateKILLSetForFlatCall(SharedLocMap curr, SharedLocMap killSet) {
 518
 519     Set<NTuple<Location>> locTupleSet = calleeIntersectBoundSharedSet.keySet();
 520     for (Iterator iterator = locTupleSet.iterator(); iterator.hasNext();) {
 521       NTuple<Location> locTupleKey = (NTuple<Location>) iterator.next();
 522       killSet.addWrite(locTupleKey, curr.get(locTupleKey));
 523     }
 524
 525   }
 526
 527   private void mergeDeleteSet(SharedLocMap currDeleteSet, SharedLocMap inDeleteLoc) {
 528
 529     Set<NTuple<Location>> locTupleKeySet = inDeleteLoc.keySet();
 530
 531     for (Iterator iterator = locTupleKeySet.iterator(); iterator.hasNext();) {
 532       NTuple<Location> locTupleKey = (NTuple<Location>) iterator.next();
 533
 534       Set<NTuple<Descriptor>> inSet = inDeleteLoc.get(locTupleKey);
 535       currDeleteSet.addWrite(locTupleKey, inSet);
 536
 537     }
 538   }
 539
 540   private void computeNewMapping(SharedLocMap curr, SharedLocMap killSet, SharedLocMap genSet) {
 541     curr.kill(killSet);
 542     curr.gen(genSet);
 543   }
 544
 545   private void updateDeleteSetForHigherWrite(SharedLocMap currDeleteSet, NTuple<Location> locTuple,
 546       NTuple<Descriptor> hp) {
 547     currDeleteSet.removeWrite(locTuple, hp);
 548   }
 549
 550   private void updateDeleteSetForSameHeightWrite(SharedLocMap currDeleteSet,
 551       NTuple<Location> locTuple, NTuple<Descriptor> hp) {
 552     currDeleteSet.addWrite(locTuple, hp);
 553   }
 554
 555   private void computeGENSetForHigherWrite(SharedLocMap curr, SharedLocMap genSet,
 556       NTuple<Location> locTuple, NTuple<Descriptor> hp) {
 557     Set<NTuple<Descriptor>> currWriteSet = curr.get(locTuple);
 558
 559     if (currWriteSet != null) {
 560       genSet.addWrite(locTuple, currWriteSet);
 561     }
 562
 563     genSet.addWrite(locTuple, hp);
 564   }
 565
 566   private void computeGENSetForSameHeightWrite(SharedLocMap curr, SharedLocMap genSet,
 567       NTuple<Location> locTuple, NTuple<Descriptor> hp) {
 568     Set<NTuple<Descriptor>> currWriteSet = curr.get(locTuple);
 569
 570     if (currWriteSet != null) {
 571       genSet.addWrite(locTuple, currWriteSet);
 572     }
 573     genSet.removeWrite(locTuple, hp);
 574   }
 575
 576   private void computeKILLSetForWrite(SharedLocMap curr, SharedLocMap killSet,
 577       NTuple<Location> locTuple, NTuple<Descriptor> hp) {
 578
 579     Set<NTuple<Descriptor>> writeSet = curr.get(locTuple);
 580     if (writeSet != null) {
 581       killSet.addWrite(locTuple, writeSet);
 582     }
 583
 584   }
 585
 586   private void mergeSharedLocMap(SharedLocMap currSharedSet, SharedLocMap in) {
 587
 588     Set<NTuple<Location>> locTupleKeySet = in.keySet();
 589     for (Iterator iterator = locTupleKeySet.iterator(); iterator.hasNext();) {
 590       NTuple<Location> locTupleKey = (NTuple<Location>) iterator.next();
 591
 592       Set<NTuple<Descriptor>> inSet = in.get(locTupleKey);
 593       Set<NTuple<Descriptor>> currSet = currSharedSet.get(locTupleKey);
 594       if (currSet == null) {
 595         currSet = new HashSet<NTuple<Descriptor>>();
 596         currSet.addAll(inSet);
 597         currSharedSet.addWrite(locTupleKey, currSet);
 598       }
 599       currSet.retainAll(inSet);
 600     }
 601
 602   }
 603
 604   private void computeSharedCoverSet() {
 605     LinkedList<MethodDescriptor> descriptorListToAnalyze =
 606         (LinkedList<MethodDescriptor>) sortedDescriptors.clone();
 607
 608     // current descriptors to visit in fixed-point interprocedural analysis,
 609     // prioritized by
 610     // dependency in the call graph
 611     methodDescriptorsToVisitStack.clear();
 612
 613     descriptorListToAnalyze.removeFirst();
 614
 615     Set<MethodDescriptor> methodDescriptorToVistSet = new HashSet<MethodDescriptor>();
 616     methodDescriptorToVistSet.addAll(descriptorListToAnalyze);
 617
 618     while (!descriptorListToAnalyze.isEmpty()) {
 619       MethodDescriptor md = descriptorListToAnalyze.removeFirst();
 620       methodDescriptorsToVisitStack.add(md);
 621     }
 622
 623     // analyze scheduled methods until there are no more to visit
 624     while (!methodDescriptorsToVisitStack.isEmpty()) {
 625       MethodDescriptor md = methodDescriptorsToVisitStack.pop();
 626       FlatMethod fm = state.getMethodFlat(md);
 627       computeSharedCoverSet_analyzeMethod(fm, md.equals(methodContainingSSJavaLoop));
 628     }
 629
 630     computeSharedCoverSetForEventLoop();
 631
 632   }
 633
 634   private void computeSharedCoverSetForEventLoop() {
 635     computeSharedCoverSet_analyzeMethod(state.getMethodFlat(methodContainingSSJavaLoop), true);
 636   }
 637
 638   private void computeSharedCoverSet_analyzeMethod(FlatMethod fm, boolean onlyVisitSSJavaLoop) {
 639
 640     System.out.println("computeSharedCoverSet_analyzeMethod=" + fm);
 641     MethodDescriptor md = fm.getMethod();
 642     Set<FlatNode> flatNodesToVisit = new HashSet<FlatNode>();
 643
 644     Set<FlatNode> visited = new HashSet<FlatNode>();
 645
 646     if (onlyVisitSSJavaLoop) {
 647       flatNodesToVisit.add(ssjava.getSSJavaLoopEntrance());
 648     } else {
 649       flatNodesToVisit.add(fm);
 650     }
 651
 652     while (!flatNodesToVisit.isEmpty()) {
 653       FlatNode fn = flatNodesToVisit.iterator().next();
 654       flatNodesToVisit.remove(fn);
 655       visited.add(fn);
 656
 657       computeSharedCoverSet_nodeActions(md, fn, onlyVisitSSJavaLoop);
 658
 659       for (int i = 0; i < fn.numNext(); i++) {
 660         FlatNode nn = fn.getNext(i);
 661
 662         if (!visited.contains(nn)) {
 663           if (!onlyVisitSSJavaLoop || (onlyVisitSSJavaLoop && loopIncElements.contains(nn))) {
 664             flatNodesToVisit.add(nn);
 665           }
 666         }
 667
 668       }
 669
 670     }
 671
 672   }
 673
 674   private void computeSharedCoverSet_nodeActions(MethodDescriptor md, FlatNode fn,
 675       boolean isEventLoopBody) {
 676     TempDescriptor lhs;
 677     TempDescriptor rhs;
 678     FieldDescriptor fld;
 679
 680     switch (fn.kind()) {
 681
 682     case FKind.FlatLiteralNode: {
 683       FlatLiteralNode fln = (FlatLiteralNode) fn;
 684       lhs = fln.getDst();
 685
 686       NTuple<Location> lhsLocTuple = new NTuple<Location>();
 687       lhsLocTuple.add(Location.createTopLocation(md));
 688       mapDescriptorToLocationPath.put(lhs, lhsLocTuple);
 689
 690       if (lhs.getType().isPrimitive() && !lhs.getSymbol().startsWith("neverused")
 691           && !lhs.getSymbol().startsWith("srctmp")) {
 692         // only need to care about composite location case here
 693         if (lhs.getType().getExtension() instanceof SSJavaType) {
 694           CompositeLocation compLoc = ((SSJavaType) lhs.getType().getExtension()).getCompLoc();
 695           Location lastLocElement = compLoc.get(compLoc.getSize() - 1);
 696           // check if the last one is shared loc
 697           if (ssjava.isSharedLocation(lastLocElement)) {
 698             addSharedLocDescriptor(lastLocElement, lhs);
 699           }
 700         }
 701       }
 702
 703     }
 704       break;
 705
 706     case FKind.FlatOpNode: {
 707       FlatOpNode fon = (FlatOpNode) fn;
 708       // for a normal assign node, need to propagate lhs's location path to
 709       // rhs
 710       if (fon.getOp().getOp() == Operation.ASSIGN) {
 711         rhs = fon.getLeft();
 712         lhs = fon.getDest();
 713
 714         if (!lhs.getSymbol().startsWith("neverused") && !lhs.getSymbol().startsWith("leftop")
 715             && !lhs.getSymbol().startsWith("rightop")) {
 716
 717           NTuple<Location> rhsLocTuple = new NTuple<Location>();
 718           NTuple<Location> lhsLocTuple = new NTuple<Location>();
 719           if (mapDescriptorToLocationPath.containsKey(rhs)) {
 720             mapDescriptorToLocationPath.put(lhs, mapDescriptorToLocationPath.get(rhs));
 721           } else {
 722             // rhs side
 723             if (rhs.getType().getExtension() != null
 724                 && rhs.getType().getExtension() instanceof SSJavaType) {
 725
 726               if (((SSJavaType) rhs.getType().getExtension()).getCompLoc() != null) {
 727                 rhsLocTuple.addAll(((SSJavaType) rhs.getType().getExtension()).getCompLoc()
 728                     .getTuple());
 729               }
 730
 731             } else {
 732               NTuple<Location> locTuple = deriveLocationTuple(md, rhs);
 733               if (locTuple != null) {
 734                 rhsLocTuple.addAll(locTuple);
 735               }
 736             }
 737             if (rhsLocTuple.size() > 0) {
 738               mapDescriptorToLocationPath.put(rhs, rhsLocTuple);
 739             }
 740
 741             // lhs side
 742             if (lhs.getType().getExtension() != null
 743                 && lhs.getType().getExtension() instanceof SSJavaType) {
 744               lhsLocTuple.addAll(((SSJavaType) lhs.getType().getExtension()).getCompLoc()
 745                   .getTuple());
 746               mapDescriptorToLocationPath.put(lhs, lhsLocTuple);
 747             } else if (mapDescriptorToLocationPath.get(rhs) != null) {
 748               // propagate rhs's location to lhs
 749               lhsLocTuple.addAll(mapDescriptorToLocationPath.get(rhs));
 750               mapDescriptorToLocationPath.put(lhs, lhsLocTuple);
 751             }
 752
 753           }
 754
 755           if (lhs.getType().isPrimitive() && !lhs.getSymbol().startsWith("srctmp")) {
 756
 757             NTuple<Descriptor> lhsHeapPath = computePath(lhs);
 758
 759             if (lhsLocTuple != null) {
 760               addMayWrittenSet(md, lhsLocTuple, lhsHeapPath);
 761             }
 762
 763           }
 764         }
 765
 766       }
 767     }
 768       break;
 769
 770     case FKind.FlatSetFieldNode:
 771     case FKind.FlatSetElementNode: {
 772
 773       // x.f=y;
 774
 775       if (fn.kind() == FKind.FlatSetFieldNode) {
 776         FlatSetFieldNode fsfn = (FlatSetFieldNode) fn;
 777         lhs = fsfn.getDst();
 778         fld = fsfn.getField();
 779         rhs = fsfn.getSrc();
 780       } else {
 781         FlatSetElementNode fsen = (FlatSetElementNode) fn;
 782         lhs = fsen.getDst();
 783         rhs = fsen.getSrc();
 784         TypeDescriptor td = lhs.getType().dereference();
 785         fld = getArrayField(td);
 786       }
 787
 788       Location fieldLocation;
 789       if (fn.kind() == FKind.FlatSetFieldNode) {
 790         fieldLocation = (Location) fld.getType().getExtension();
 791       } else {
 792         NTuple<Location> locTuple = mapDescriptorToLocationPath.get(lhs);
 793         fieldLocation = locTuple.get(locTuple.size() - 1);
 794       }
 795
 796       if (!isEventLoopBody && fieldLocation.getDescriptor().equals(md)) {
 797         // if the field belongs to the local lattice, no reason to calculate
 798         // shared location
 799         break;
 800       }
 801
 802       NTuple<Location> fieldLocTuple = new NTuple<Location>();
 803       if (fld.isStatic()) {
 804         if (fld.isFinal()) {
 805           // in this case, fld has TOP location
 806           Location topLocation = Location.createTopLocation(md);
 807           fieldLocTuple.add(topLocation);
 808         } else {
 809           fieldLocTuple.addAll(deriveGlobalLocationTuple(md));
 810           if (fn.kind() == FKind.FlatSetFieldNode) {
 811             fieldLocTuple.add((Location) fld.getType().getExtension());
 812           }
 813         }
 814
 815       } else {
 816         fieldLocTuple.addAll(deriveLocationTuple(md, lhs));
 817         if (fn.kind() == FKind.FlatSetFieldNode) {
 818           fieldLocTuple.add((Location) fld.getType().getExtension());
 819         }
 820       }
 821
 822       NTuple<Location> lTuple = deriveLocationTuple(md, lhs);
 823       if (lTuple != null) {
 824         NTuple<Location> lhsLocTuple = new NTuple<Location>();
 825         lhsLocTuple.addAll(lTuple);
 826         mapDescriptorToLocationPath.put(lhs, lhsLocTuple);
 827       }
 828
 829       if (ssjava.isSharedLocation(fieldLocation)) {
 830         addSharedLocDescriptor(fieldLocation, fld);
 831
 832         NTuple<Descriptor> fieldHeapPath = new NTuple<Descriptor>();
 833         fieldHeapPath.addAll(computePath(lhs));
 834         fieldHeapPath.add(fld);
 835
 836         // mapLocationPathToMayWrittenSet.put(locTuple, null, fld);
 837         addMayWrittenSet(md, fieldLocTuple, fieldHeapPath);
 838
 839       }
 840
 841     }
 842       break;
 843
 844     case FKind.FlatElementNode:
 845     case FKind.FlatFieldNode: {
 846
 847       // x=y.f;
 848
 849       if (fn.kind() == FKind.FlatFieldNode) {
 850         FlatFieldNode ffn = (FlatFieldNode) fn;
 851         lhs = ffn.getDst();
 852         rhs = ffn.getSrc();
 853         fld = ffn.getField();
 854       } else {
 855         FlatElementNode fen = (FlatElementNode) fn;
 856         lhs = fen.getDst();
 857         rhs = fen.getSrc();
 858         TypeDescriptor td = rhs.getType().dereference();
 859         fld = getArrayField(td);
 860       }
 861
 862       NTuple<Location> locTuple = new NTuple<Location>();
 863
 864       if (fld.isStatic()) {
 865
 866         if (fld.isFinal()) {
 867           // in this case, fld has TOP location
 868           Location topLocation = Location.createTopLocation(md);
 869           locTuple.add(topLocation);
 870         } else {
 871           locTuple.addAll(deriveGlobalLocationTuple(md));
 872           if (fn.kind() == FKind.FlatFieldNode) {
 873             locTuple.add((Location) fld.getType().getExtension());
 874           }
 875         }
 876
 877       } else {
 878         locTuple.addAll(deriveLocationTuple(md, rhs));
 879         if (fn.kind() == FKind.FlatFieldNode) {
 880           locTuple.add((Location) fld.getType().getExtension());
 881         }
 882       }
 883
 884       mapDescriptorToLocationPath.put(lhs, locTuple);
 885
 886     }
 887       break;
 888
 889     case FKind.FlatCall: {
 890
 891       FlatCall fc = (FlatCall) fn;
 892
 893       if (ssjava.needTobeAnnotated(fc.getMethod())) {
 894         bindLocationPathCallerArgWithCalleeParam(md, fc);
 895       }
 896
 897     }
 898       break;
 899
 900     case FKind.FlatNew: {
 901
 902       FlatNew fnew = (FlatNew) fn;
 903       TempDescriptor dst = fnew.getDst();
 904       NTuple<Location> locTuple = deriveLocationTuple(md, dst);
 905
 906       if (locTuple != null) {
 907         NTuple<Location> dstLocTuple = new NTuple<Location>();
 908         dstLocTuple.addAll(locTuple);
 909         mapDescriptorToLocationPath.put(dst, dstLocTuple);
 910       }
 911
 912     }
 913       break;
 914     }
 915   }
 916
 917   private void addMayWrittenSet(MethodDescriptor md, NTuple<Location> locTuple,
 918       NTuple<Descriptor> heapPath) {
 919
 920     MultiSourceMap<NTuple<Location>, NTuple<Descriptor>> map = mapMethodToSharedLocCoverSet.get(md);
 921     if (map == null) {
 922       map = new MultiSourceMap<NTuple<Location>, NTuple<Descriptor>>();
 923       mapMethodToSharedLocCoverSet.put(md, map);
 924     }
 925
 926     Set<NTuple<Descriptor>> writeSet = map.get(locTuple);
 927     if (writeSet == null) {
 928       writeSet = new HashSet<NTuple<Descriptor>>();
 929       map.put(locTuple, writeSet);
 930     }
 931     writeSet.add(heapPath);
 932
 933   }
 934
 935   private void bindLocationPathCallerArgWithCalleeParam(MethodDescriptor mdCaller, FlatCall fc) {
 936
 937     if (ssjava.isSSJavaUtil(fc.getMethod().getClassDesc())) {
 938       // ssjava util case!
 939       // have write effects on the first argument
 940       TempDescriptor arg = fc.getArg(0);
 941       NTuple<Location> argLocationPath = deriveLocationTuple(mdCaller, arg);
 942       NTuple<Descriptor> argHeapPath = computePath(arg);
 943       addMayWrittenSet(mdCaller, argLocationPath, argHeapPath);
 944     } else {
 945
 946       // if arg is not primitive type, we need to propagate maywritten set to
 947       // the caller's location path
 948
 949       MethodDescriptor mdCallee = fc.getMethod();
 950       Set<MethodDescriptor> setPossibleCallees = new HashSet<MethodDescriptor>();
 951       setPossibleCallees.addAll(callGraph.getMethods(mdCallee));
 952
 953       // create mapping from arg idx to its heap paths
 954       Hashtable<Integer, NTuple<Descriptor>> mapArgIdx2CallerArgHeapPath =
 955           new Hashtable<Integer, NTuple<Descriptor>>();
 956
 957       // create mapping from arg idx to its location paths
 958       Hashtable<Integer, NTuple<Location>> mapArgIdx2CallerArgLocationPath =
 959           new Hashtable<Integer, NTuple<Location>>();
 960
 961       // arg idx is starting from 'this' arg
 962       if (fc.getThis() != null) {
 963         // loc path for 'this'
 964         NTuple<Location> thisLocationPath = deriveLocationTuple(mdCaller, fc.getThis());
 965         if (thisLocationPath != null) {
 966           mapArgIdx2CallerArgLocationPath.put(Integer.valueOf(0), thisLocationPath);
 967
 968           // heap path for 'this'
 969           NTuple<Descriptor> thisHeapPath = mapHeapPath.get(fc.getThis());
 970           if (thisHeapPath == null) {
 971             // method is called without creating new flat node representing
 972             // 'this'
 973             thisHeapPath = new NTuple<Descriptor>();
 974             thisHeapPath.add(fc.getThis());
 975           }
 976           mapArgIdx2CallerArgHeapPath.put(Integer.valueOf(0), thisHeapPath);
 977         }
 978
 979       }
 980
 981       for (int i = 0; i < fc.numArgs(); i++) {
 982         TempDescriptor arg = fc.getArg(i);
 983         // create mapping arg to loc path
 984         NTuple<Location> argLocationPath = deriveLocationTuple(mdCaller, arg);
 985         if (argLocationPath != null) {
 986           mapArgIdx2CallerArgLocationPath.put(Integer.valueOf(i + 1), argLocationPath);
 987           // create mapping arg to heap path
 988           NTuple<Descriptor> argHeapPath = computePath(arg);
 989           mapArgIdx2CallerArgHeapPath.put(Integer.valueOf(i + 1), argHeapPath);
 990         }
 991
 992       }
 993
 994       Hashtable<Integer, Set<NTuple<Descriptor>>> mapParamIdx2WriteSet =
 995           new Hashtable<Integer, Set<NTuple<Descriptor>>>();
 996
 997       for (int i = 0; i < fc.numArgs() + 1; i++) {
 998         mapParamIdx2WriteSet.put(Integer.valueOf(i), new HashSet<NTuple<Descriptor>>());
 999       }
1000
1001       for (Iterator iterator = setPossibleCallees.iterator(); iterator.hasNext();) {
1002         MethodDescriptor callee = (MethodDescriptor) iterator.next();
1003         FlatMethod calleeFlatMethod = state.getMethodFlat(callee);
1004
1005         // binding caller's args and callee's params
1006
1007         Hashtable<Integer, TempDescriptor> mapParamIdx2ParamTempDesc =
1008             new Hashtable<Integer, TempDescriptor>();
1009         int offset = 0;
1010         if (calleeFlatMethod.getMethod().isStatic()) {
1011           // static method does not have implicit 'this' arg
1012           offset = 1;
1013         }
1014         for (int i = 0; i < calleeFlatMethod.numParameters(); i++) {
1015           TempDescriptor param = calleeFlatMethod.getParameter(i);
1016           mapParamIdx2ParamTempDesc.put(Integer.valueOf(i + offset), param);
1017         }
1018
1019         Set<Integer> keySet = mapArgIdx2CallerArgLocationPath.keySet();
1020         for (Iterator iterator2 = keySet.iterator(); iterator2.hasNext();) {
1021           Integer idx = (Integer) iterator2.next();
1022           NTuple<Location> callerArgLocationPath = mapArgIdx2CallerArgLocationPath.get(idx);
1023
1024           TempDescriptor calleeParam = mapParamIdx2ParamTempDesc.get(idx);
1025
1026           NTuple<Descriptor> callerArgHeapPath = mapArgIdx2CallerArgHeapPath.get(idx);
1027           NTuple<Location> calleeLocationPath = deriveLocationTuple(mdCallee, calleeParam);
1028           NTuple<Descriptor> calleeHeapPath = computePath(calleeParam);
1029
1030           createNewMappingOfMayWrittenSet(mdCaller, callee, callerArgHeapPath,
1031               callerArgLocationPath, calleeHeapPath, calleeLocationPath,
1032               mapParamIdx2WriteSet.get(idx));
1033
1034         }
1035
1036       }
1037
1038     }
1039
1040   }
1041
1042   private Hashtable<NTuple<Location>, Set<NTuple<Descriptor>>> getMappingByStartedWith(
1043       MultiSourceMap<NTuple<Location>, NTuple<Descriptor>> map, NTuple<Location> in) {
1044
1045     Hashtable<NTuple<Location>, Set<NTuple<Descriptor>>> matchedMapping =
1046         new Hashtable<NTuple<Location>, Set<NTuple<Descriptor>>>();
1047
1048     Set<NTuple<Location>> keySet = map.keySet();
1049
1050     for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
1051       NTuple<Location> key = (NTuple<Location>) iterator.next();
1052       if (key.startsWith(in)) {
1053         matchedMapping.put(key, map.get(key));
1054       }
1055     }
1056
1057     return matchedMapping;
1058
1059   }
1060
1061   private void createNewMappingOfMayWrittenSet(MethodDescriptor caller, MethodDescriptor callee,
1062       NTuple<Descriptor> callerArgHeapPath, NTuple<Location> callerArgLocPath,
1063       NTuple<Descriptor> calleeParamHeapPath, NTuple<Location> calleeParamLocPath,
1064       Set<NTuple<Descriptor>> writeSet) {
1065
1066     // propagate may-written-set associated with the key that is started with
1067     // calleepath to the caller
1068     // 1) makes a new key by combining caller path and callee path(except local
1069     // loc element of param)
1070     // 2) create new mapping of may-written-set of callee path to caller path
1071
1072     // extract all may written effect accessed through callee param path
1073     MultiSourceMap<NTuple<Location>, NTuple<Descriptor>> calleeMapping =
1074         mapMethodToSharedLocCoverSet.get(callee);
1075
1076     MultiSourceMap<NTuple<Location>, NTuple<Descriptor>> callerMapping =
1077         mapMethodToSharedLocCoverSet.get(caller);
1078
1079     if (callerMapping == null) {
1080       callerMapping = new MultiSourceMap<NTuple<Location>, NTuple<Descriptor>>();
1081       mapMethodToSharedLocCoverSet.put(caller, callerMapping);
1082     }
1083
1084     if (calleeMapping == null) {
1085       return;
1086     }
1087
1088     Hashtable<NTuple<Location>, Set<NTuple<Descriptor>>> paramMapping =
1089         getMappingByStartedWith(calleeMapping, calleeParamLocPath);
1090
1091     Set<NTuple<Location>> calleeKeySet = calleeMapping.keySet();
1092     for (Iterator iterator = calleeKeySet.iterator(); iterator.hasNext();) {
1093       NTuple<Location> calleeKey = (NTuple<Location>) iterator.next();
1094       Set<NTuple<Descriptor>> calleeMayWriteSet = paramMapping.get(calleeKey);
1095
1096       if (calleeMayWriteSet != null) {
1097
1098         Set<NTuple<Descriptor>> boundWriteSet =
1099             convertCallerMayWriteSet(callerArgHeapPath, calleeParamHeapPath, calleeMayWriteSet);
1100
1101         writeSet.addAll(boundWriteSet);
1102
1103         NTuple<Location> newKey = new NTuple<Location>();
1104         newKey.addAll(callerArgLocPath);
1105         // need to replace the local location with the caller's path so skip the
1106         // local location of the parameter
1107         for (int i = 1; i < calleeKey.size(); i++) {
1108           newKey.add(calleeKey.get(i));
1109         }
1110
1111         callerMapping.union(newKey, writeSet);
1112         // mapLocationPathToMayWrittenSet.put(calleeKey, newKey, writeSet);
1113       }
1114
1115     }
1116
1117   }
1118
1119   private Set<NTuple<Descriptor>> convertCallerMayWriteSet(NTuple<Descriptor> callerArgHeapPath,
1120       NTuple<Descriptor> calleeParamHeapPath, Set<NTuple<Descriptor>> calleeMayWriteSet) {
1121
1122     Set<NTuple<Descriptor>> boundSet = new HashSet<NTuple<Descriptor>>();
1123
1124     // replace callee's param path with caller's arg path
1125     for (Iterator iterator = calleeMayWriteSet.iterator(); iterator.hasNext();) {
1126       NTuple<Descriptor> calleeWriteHeapPath = (NTuple<Descriptor>) iterator.next();
1127
1128       NTuple<Descriptor> boundHeapPath = new NTuple<Descriptor>();
1129       boundHeapPath.addAll(callerArgHeapPath);
1130
1131       int startIdx = calleeParamHeapPath.size();
1132
1133       for (int i = startIdx; i < calleeWriteHeapPath.size(); i++) {
1134         boundHeapPath.add(calleeWriteHeapPath.get(i));
1135       }
1136
1137       boundSet.add(boundHeapPath);
1138
1139     }
1140
1141     return boundSet;
1142   }
1143
1144   private void addSharedLocDescriptor(Location sharedLoc, Descriptor desc) {
1145
1146     Set<Descriptor> descSet = mapSharedLocationToCoverSet.get(sharedLoc);
1147     if (descSet == null) {
1148       descSet = new HashSet<Descriptor>();
1149       mapSharedLocationToCoverSet.put(sharedLoc, descSet);
1150     }
1151
1152     descSet.add(desc);
1153
1154   }
1155
1156   private Location getLocation(Descriptor d) {
1157
1158     if (d instanceof FieldDescriptor) {
1159       TypeExtension te = ((FieldDescriptor) d).getType().getExtension();
1160       if (te != null) {
1161         return (Location) te;
1162       }
1163     } else {
1164       assert d instanceof TempDescriptor;
1165       TempDescriptor td = (TempDescriptor) d;
1166
1167       TypeExtension te = td.getType().getExtension();
1168       if (te != null) {
1169         if (te instanceof SSJavaType) {
1170           SSJavaType ssType = (SSJavaType) te;
1171           if (ssType.getCompLoc() != null) {
1172             CompositeLocation comp = ssType.getCompLoc();
1173             return comp.get(comp.getSize() - 1);
1174           } else {
1175             return null;
1176           }
1177         } else {
1178           return (Location) te;
1179         }
1180       }
1181     }
1182
1183     return mapDescToLocation.get(d);
1184   }
1185
1186   private void eventLoopAnalysis() {
1187     // perform second stage analysis: intraprocedural analysis ensure that
1188     // all
1189     // variables are definitely written in-between the same read
1190
1191     Set<FlatNode> flatNodesToVisit = new HashSet<FlatNode>();
1192     flatNodesToVisit.add(ssjava.getSSJavaLoopEntrance());
1193
1194     while (!flatNodesToVisit.isEmpty()) {
1195       FlatNode fn = (FlatNode) flatNodesToVisit.iterator().next();
1196       flatNodesToVisit.remove(fn);
1197
1198       Hashtable<NTuple<Descriptor>, Set<WriteAge>> prev = mapFlatNodetoEventLoopMap.get(fn);
1199
1200       Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr =
1201           new Hashtable<NTuple<Descriptor>, Set<WriteAge>>();
1202       for (int i = 0; i < fn.numPrev(); i++) {
1203         FlatNode nn = fn.getPrev(i);
1204         Hashtable<NTuple<Descriptor>, Set<WriteAge>> in = mapFlatNodetoEventLoopMap.get(nn);
1205         if (in != null) {
1206           union(curr, in);
1207         }
1208       }
1209
1210       eventLoopAnalysis_nodeAction(fn, curr, ssjava.getSSJavaLoopEntrance());
1211
1212       // if a new result, schedule forward nodes for analysis
1213       if (!curr.equals(prev)) {
1214         mapFlatNodetoEventLoopMap.put(fn, curr);
1215
1216         for (int i = 0; i < fn.numNext(); i++) {
1217           FlatNode nn = fn.getNext(i);
1218           if (loopIncElements.contains(nn)) {
1219             flatNodesToVisit.add(nn);
1220           }
1221
1222         }
1223       }
1224     }
1225   }
1226
1227   private void union(Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr,
1228       Hashtable<NTuple<Descriptor>, Set<WriteAge>> in) {
1229
1230     Set<NTuple<Descriptor>> inKeySet = in.keySet();
1231     for (Iterator iterator = inKeySet.iterator(); iterator.hasNext();) {
1232       NTuple<Descriptor> inKey = (NTuple<Descriptor>) iterator.next();
1233       Set<WriteAge> inSet = in.get(inKey);
1234
1235       Set<WriteAge> currSet = curr.get(inKey);
1236
1237       if (currSet == null) {
1238         currSet = new HashSet<WriteAge>();
1239         curr.put(inKey, currSet);
1240       }
1241       currSet.addAll(inSet);
1242     }
1243
1244   }
1245
1246   private void eventLoopAnalysis_nodeAction(FlatNode fn,
1247       Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr, FlatNode loopEntrance) {
1248
1249     Hashtable<NTuple<Descriptor>, Set<WriteAge>> readWriteKillSet =
1250         new Hashtable<NTuple<Descriptor>, Set<WriteAge>>();
1251     Hashtable<NTuple<Descriptor>, Set<WriteAge>> readWriteGenSet =
1252         new Hashtable<NTuple<Descriptor>, Set<WriteAge>>();
1253
1254     if (fn.equals(loopEntrance)) {
1255       // it reaches loop entrance: changes all flag to true
1256       Set<NTuple<Descriptor>> keySet = curr.keySet();
1257       for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
1258         NTuple<Descriptor> key = (NTuple<Descriptor>) iterator.next();
1259         Set<WriteAge> writeAgeSet = curr.get(key);
1260
1261         Set<WriteAge> incSet = new HashSet<WriteAge>();
1262         incSet.addAll(writeAgeSet);
1263         writeAgeSet.clear();
1264
1265         for (Iterator iterator2 = incSet.iterator(); iterator2.hasNext();) {
1266           WriteAge writeAge = (WriteAge) iterator2.next();
1267           WriteAge newWriteAge = writeAge.copy();
1268           newWriteAge.inc();
1269           writeAgeSet.add(newWriteAge);
1270         }
1271
1272       }
1273
1274     } else {
1275       TempDescriptor lhs;
1276       TempDescriptor rhs;
1277       FieldDescriptor fld;
1278
1279       switch (fn.kind()) {
1280
1281       case FKind.FlatOpNode: {
1282         FlatOpNode fon = (FlatOpNode) fn;
1283         lhs = fon.getDest();
1284         rhs = fon.getLeft();
1285
1286         if (fon.getOp().getOp() == Operation.ASSIGN) {
1287
1288           if (!lhs.getSymbol().startsWith("neverused") && !lhs.getSymbol().startsWith("leftop")
1289               && !lhs.getSymbol().startsWith("rightop")) {
1290
1291             boolean hasWriteEffect = false;
1292             NTuple<Descriptor> rhsHeapPath = computePath(rhs);
1293
1294             if (rhs.getType().getExtension() instanceof SSJavaType
1295                 && lhs.getType().getExtension() instanceof SSJavaType) {
1296
1297               CompositeLocation rhsCompLoc =
1298                   ((SSJavaType) rhs.getType().getExtension()).getCompLoc();
1299
1300               CompositeLocation lhsCompLoc =
1301                   ((SSJavaType) lhs.getType().getExtension()).getCompLoc();
1302
1303               if (lhsCompLoc != rhsCompLoc) {
1304                 // have a write effect!
1305                 hasWriteEffect = true;
1306               }
1307
1308             } else if (lhs.getType().isImmutable()) {
1309               hasWriteEffect = true;
1310             }
1311
1312             if (hasWriteEffect) {
1313               // write(lhs)
1314               NTuple<Descriptor> lhsPath = new NTuple<Descriptor>();
1315               lhsPath.add(lhs);
1316               Location lhsLoc = getLocation(lhs);
1317               if (ssjava.isSharedLocation(lhsLoc)) {
1318
1319                 NTuple<Descriptor> varHeapPath = computePath(lhs);
1320                 NTuple<Location> varLocTuple = mapDescriptorToLocationPath.get(lhs);
1321
1322                 Set<NTuple<Descriptor>> writtenSet =
1323                     mapFlatNodeToSharedLocMapping.get(fn).get(varLocTuple);
1324
1325                 if (isCovered(varLocTuple, writtenSet)) {
1326                   computeKILLSetForSharedWrite(curr, writtenSet, readWriteKillSet);
1327                   computeGENSetForSharedAllCoverWrite(curr, writtenSet, readWriteGenSet);
1328                 } else {
1329                   computeGENSetForSharedNonCoverWrite(curr, varHeapPath, readWriteGenSet);
1330                 }
1331
1332               } else {
1333
1334                 computeKILLSetForWrite(curr, lhsPath, readWriteKillSet);
1335                 computeGENSetForWrite(lhsPath, readWriteGenSet);
1336               }
1337
1338               // System.out.println("#KILLSET=" + readWriteKillSet);
1339               // System.out.println("#GENSet=" + readWriteGenSet + "\n");
1340
1341               Set<WriteAge> writeAgeSet = curr.get(lhsPath);
1342               checkWriteAgeSet(writeAgeSet, lhsPath, fn);
1343             }
1344
1345           }
1346
1347         }
1348
1349       }
1350         break;
1351
1352       case FKind.FlatFieldNode:
1353       case FKind.FlatElementNode: {
1354
1355         if (fn.kind() == FKind.FlatFieldNode) {
1356           FlatFieldNode ffn = (FlatFieldNode) fn;
1357           lhs = ffn.getDst();
1358           rhs = ffn.getSrc();
1359           fld = ffn.getField();
1360         } else {
1361           FlatElementNode fen = (FlatElementNode) fn;
1362           lhs = fen.getDst();
1363           rhs = fen.getSrc();
1364           TypeDescriptor td = rhs.getType().dereference();
1365           fld = getArrayField(td);
1366         }
1367
1368         // read field
1369         NTuple<Descriptor> srcHeapPath = mapHeapPath.get(rhs);
1370         NTuple<Descriptor> fldHeapPath;
1371         if (srcHeapPath != null) {
1372           fldHeapPath = new NTuple<Descriptor>(srcHeapPath.getList());
1373         } else {
1374           // if srcHeapPath is null, it is static reference
1375           fldHeapPath = new NTuple<Descriptor>();
1376           fldHeapPath.add(rhs);
1377         }
1378         fldHeapPath.add(fld);
1379
1380         Set<WriteAge> writeAgeSet = curr.get(fldHeapPath);
1381
1382         checkWriteAgeSet(writeAgeSet, fldHeapPath, fn);
1383
1384       }
1385         break;
1386
1387       case FKind.FlatSetFieldNode:
1388       case FKind.FlatSetElementNode: {
1389
1390         if (fn.kind() == FKind.FlatSetFieldNode) {
1391           FlatSetFieldNode fsfn = (FlatSetFieldNode) fn;
1392           lhs = fsfn.getDst();
1393           fld = fsfn.getField();
1394         } else {
1395           FlatSetElementNode fsen = (FlatSetElementNode) fn;
1396           lhs = fsen.getDst();
1397           rhs = fsen.getSrc();
1398           TypeDescriptor td = lhs.getType().dereference();
1399           fld = getArrayField(td);
1400         }
1401
1402         // System.out.println("FIELD WRITE:" + fn);
1403
1404         // write(field)
1405         NTuple<Descriptor> lhsHeapPath = computePath(lhs);
1406         NTuple<Descriptor> fldHeapPath = new NTuple<Descriptor>(lhsHeapPath.getList());
1407         fldHeapPath.add(fld);
1408
1409         // shared loc extension
1410         Location fieldLoc = (Location) fld.getType().getExtension();
1411         if (ssjava.isSharedLocation(fieldLoc)) {
1412
1413           NTuple<Location> fieldLocTuple = new NTuple<Location>();
1414           fieldLocTuple.addAll(mapDescriptorToLocationPath.get(lhs));
1415           fieldLocTuple.add(fieldLoc);
1416
1417           Set<NTuple<Descriptor>> writtenSet =
1418               mapFlatNodeToSharedLocMapping.get(fn).get(fieldLocTuple);
1419
1420           if (isCovered(fieldLocTuple, writtenSet)) {
1421             computeKILLSetForSharedWrite(curr, writtenSet, readWriteKillSet);
1422             computeGENSetForSharedAllCoverWrite(curr, writtenSet, readWriteGenSet);
1423           } else {
1424             computeGENSetForSharedNonCoverWrite(curr, fldHeapPath, readWriteGenSet);
1425           }
1426
1427         } else {
1428           computeKILLSetForWrite(curr, fldHeapPath, readWriteKillSet);
1429           computeGENSetForWrite(fldHeapPath, readWriteGenSet);
1430         }
1431
1432         // System.out.println("KILLSET=" + readWriteKillSet);
1433         // System.out.println("GENSet=" + readWriteGenSet);
1434
1435       }
1436         break;
1437
1438       case FKind.FlatCall: {
1439         FlatCall fc = (FlatCall) fn;
1440
1441         SharedLocMap sharedLocMap = mapFlatNodeToSharedLocMapping.get(fc);
1442         // System.out.println("FLATCALL:" + fn);
1443         generateKILLSetForFlatCall(fc, curr, sharedLocMap, readWriteKillSet);
1444         generateGENSetForFlatCall(fc, sharedLocMap, readWriteGenSet);
1445
1446 //        System.out.println("KILLSET=" + readWriteKillSet);
1447 //        System.out.println("GENSet=" + readWriteGenSet);
1448
1449         checkManyRead(fc, curr);
1450       }
1451         break;
1452
1453       }
1454
1455       computeNewMapping(curr, readWriteKillSet, readWriteGenSet);
1456 //      System.out.println("#######" + curr);
1457
1458     }
1459
1460   }
1461
1462   private void computeGENSetForSharedNonCoverWrite(
1463       Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr, NTuple<Descriptor> heapPath,
1464       Hashtable<NTuple<Descriptor>, Set<WriteAge>> genSet) {
1465
1466     Set<WriteAge> writeAgeSet = genSet.get(heapPath);
1467     if (writeAgeSet == null) {
1468       writeAgeSet = new HashSet<WriteAge>();
1469       genSet.put(heapPath, writeAgeSet);
1470     }
1471
1472     writeAgeSet.add(new WriteAge(1));
1473
1474   }
1475
1476   private void computeGENSetForSharedAllCoverWrite(
1477       Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr, Set<NTuple<Descriptor>> writtenSet,
1478       Hashtable<NTuple<Descriptor>, Set<WriteAge>> genSet) {
1479
1480     for (Iterator iterator = writtenSet.iterator(); iterator.hasNext();) {
1481       NTuple<Descriptor> writeHeapPath = (NTuple<Descriptor>) iterator.next();
1482
1483       Set<WriteAge> writeAgeSet = new HashSet<WriteAge>();
1484       writeAgeSet.add(new WriteAge(0));
1485
1486       genSet.put(writeHeapPath, writeAgeSet);
1487     }
1488
1489   }
1490
1491   private void computeKILLSetForSharedWrite(Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr,
1492       Set<NTuple<Descriptor>> writtenSet, Hashtable<NTuple<Descriptor>, Set<WriteAge>> killSet) {
1493
1494     for (Iterator iterator = writtenSet.iterator(); iterator.hasNext();) {
1495       NTuple<Descriptor> writeHeapPath = (NTuple<Descriptor>) iterator.next();
1496       Set<WriteAge> writeSet = curr.get(writeHeapPath);
1497       if (writeSet != null) {
1498         killSet.put(writeHeapPath, writeSet);
1499       }
1500     }
1501
1502   }
1503
1504   private boolean isCovered(NTuple<Location> locTuple, Set<NTuple<Descriptor>> inSet) {
1505
1506     if (inSet == null) {
1507       return false;
1508     }
1509
1510     Set<NTuple<Descriptor>> coverSet =
1511         mapMethodToSharedLocCoverSet.get(methodContainingSSJavaLoop).get(locTuple);
1512
1513     return inSet.containsAll(coverSet);
1514   }
1515
1516   private void checkManyRead(FlatCall fc, Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr) {
1517
1518     Set<NTuple<Descriptor>> boundReadSet = mapFlatNodeToBoundReadSet.get(fc);
1519
1520     for (Iterator iterator = boundReadSet.iterator(); iterator.hasNext();) {
1521       NTuple<Descriptor> readHeapPath = (NTuple<Descriptor>) iterator.next();
1522       Set<WriteAge> writeAgeSet = curr.get(readHeapPath);
1523       checkWriteAgeSet(writeAgeSet, readHeapPath, fc);
1524     }
1525
1526   }
1527
1528   private void checkWriteAgeSet(Set<WriteAge> writeAgeSet, NTuple<Descriptor> path, FlatNode fn) {
1529
1530     // System.out.println("# CHECK WRITE AGE of " + path + " from set=" +
1531     // writeAgeSet);
1532
1533     if (writeAgeSet != null) {
1534       for (Iterator iterator = writeAgeSet.iterator(); iterator.hasNext();) {
1535         WriteAge writeAge = (WriteAge) iterator.next();
1536         if (writeAge.getAge() > MAXAGE) {
1537           generateErrorMessage(path, fn);
1538         }
1539       }
1540     }
1541   }
1542
1543   private void generateErrorMessage(NTuple<Descriptor> path, FlatNode fn) {
1544
1545     Descriptor lastDesc = path.get(path.size() - 1);
1546     if (ssjava.isSharedLocation(getLocation(lastDesc))) {
1547
1548       NTuple<Location> locPathTuple = getLocationTuple(path);
1549       Set<NTuple<Descriptor>> coverSet =
1550           mapMethodToSharedLocCoverSet.get(methodContainingSSJavaLoop).get(locPathTuple);
1551       throw new Error("Shared memory locations, which is reachable through references " + path
1552           + ", are not completely overwritten by the higher values at "
1553           + methodContainingSSJavaLoop.getClassDesc().getSourceFileName() + "::" + fn.getNumLine()
1554           + ".\nThe following memory locations belong to the same shared locations:" + coverSet);
1555
1556     } else {
1557       throw new Error(
1558           "Memory location, which is reachable through references "
1559               + path
1560               + ", who comes back to the same read statement without being overwritten at the out-most iteration at "
1561               + methodContainingSSJavaLoop.getClassDesc().getSourceFileName() + "::"
1562               + fn.getNumLine());
1563     }
1564
1565   }
1566
1567   private void generateGENSetForFlatCall(FlatCall fc, SharedLocMap sharedLocMap,
1568       Hashtable<NTuple<Descriptor>, Set<WriteAge>> GENSet) {
1569
1570     Set<NTuple<Descriptor>> boundMayWriteSet = mapFlatNodeToBoundMayWriteSet.get(fc);
1571 //    System.out.println("boundMayWriteSet=" + boundMayWriteSet);
1572
1573     for (Iterator iterator = boundMayWriteSet.iterator(); iterator.hasNext();) {
1574       NTuple<Descriptor> heapPath = (NTuple<Descriptor>) iterator.next();
1575
1576       if (!isSharedLocation(heapPath)) {
1577         addWriteAgeToSet(heapPath, GENSet, new WriteAge(0));
1578       } else {
1579         // if the current heap path is shared location
1580
1581         NTuple<Location> locTuple = getLocationTuple(heapPath);
1582
1583         Set<NTuple<Descriptor>> sharedWriteHeapPathSet = sharedLocMap.get(locTuple);
1584
1585         if (isCovered(locTuple, sharedLocMap.get(locTuple))) {
1586           // if it is covered, add all of heap paths belong to the same shared
1587           // loc with write age 0
1588
1589           for (Iterator iterator2 = sharedWriteHeapPathSet.iterator(); iterator2.hasNext();) {
1590             NTuple<Descriptor> sharedHeapPath = (NTuple<Descriptor>) iterator2.next();
1591             addWriteAgeToSet(sharedHeapPath, GENSet, new WriteAge(0));
1592           }
1593
1594         } else {
1595           // if not covered, add write age 1 to the heap path that is
1596           // may-written but not covered
1597           addWriteAgeToSet(heapPath, GENSet, new WriteAge(1));
1598         }
1599
1600       }
1601
1602     }
1603
1604   }
1605
1606   private void addWriteAgeToSet(NTuple<Descriptor> heapPath,
1607       Hashtable<NTuple<Descriptor>, Set<WriteAge>> map, WriteAge age) {
1608
1609     Set<WriteAge> currSet = map.get(heapPath);
1610     if (currSet == null) {
1611       currSet = new HashSet<WriteAge>();
1612       map.put(heapPath, currSet);
1613     }
1614
1615     currSet.add(age);
1616   }
1617
1618   private void generateKILLSetForFlatCall(FlatCall fc,
1619       Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr, SharedLocMap sharedLocMap,
1620       Hashtable<NTuple<Descriptor>, Set<WriteAge>> KILLSet) {
1621
1622     Set<NTuple<Descriptor>> boundMustWriteSet = mapFlatNodeToBoundMustWriteSet.get(fc);
1623 //    System.out.println("boundMustWriteSet=" + boundMustWriteSet);
1624
1625     for (Iterator iterator = boundMustWriteSet.iterator(); iterator.hasNext();) {
1626       NTuple<Descriptor> heapPath = (NTuple<Descriptor>) iterator.next();
1627
1628       if (isSharedLocation(heapPath)) {
1629         NTuple<Location> locTuple = getLocationTuple(heapPath);
1630
1631         if (isCovered(locTuple, sharedLocMap.get(locTuple))) {
1632           // if it is shared loc and corresponding shared loc has been covered
1633           KILLSet.put(heapPath, curr.get(heapPath));
1634         }
1635       } else {
1636         if (curr.get(heapPath) != null) {
1637           KILLSet.put(heapPath, curr.get(heapPath));
1638         }
1639       }
1640
1641     }
1642
1643   }
1644
1645   private int getArrayBaseDescriptorIdx(NTuple<Descriptor> heapPath) {
1646
1647     for (int i = heapPath.size() - 1; i > 1; i--) {
1648       if (!heapPath.get(i).getSymbol().equals(arrayElementFieldName)) {
1649         return i;
1650       }
1651     }
1652
1653     return -1;
1654
1655   }
1656
1657   private boolean isSharedLocation(NTuple<Descriptor> heapPath) {
1658
1659     Descriptor d = heapPath.get(heapPath.size() - 1);
1660
1661     if (d instanceof FieldDescriptor) {
1662
1663       return ssjava
1664           .isSharedLocation(getLocation(heapPath.get(getArrayBaseDescriptorIdx(heapPath))));
1665
1666     } else {
1667       return ssjava.isSharedLocation(getLocation(heapPath.get(heapPath.size() - 1)));
1668     }
1669   }
1670
1671   private NTuple<Location> getLocationTuple(NTuple<Descriptor> heapPath) {
1672
1673     NTuple<Location> locTuple = new NTuple<Location>();
1674
1675     locTuple.addAll(mapDescriptorToLocationPath.get(heapPath.get(0)));
1676
1677     for (int i = 1; i <= getArrayBaseDescriptorIdx(heapPath); i++) {
1678       locTuple.add(getLocation(heapPath.get(i)));
1679     }
1680
1681     return locTuple;
1682   }
1683
1684   private void computeNewMapping(Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr,
1685       Hashtable<NTuple<Descriptor>, Set<WriteAge>> KILLSet,
1686       Hashtable<NTuple<Descriptor>, Set<WriteAge>> GENSet) {
1687
1688     for (Enumeration<NTuple<Descriptor>> e = KILLSet.keys(); e.hasMoreElements();) {
1689       NTuple<Descriptor> key = e.nextElement();
1690
1691       Set<WriteAge> writeAgeSet = curr.get(key);
1692       if (writeAgeSet == null) {
1693         writeAgeSet = new HashSet<WriteAge>();
1694         curr.put(key, writeAgeSet);
1695       }
1696       writeAgeSet.removeAll(KILLSet.get(key));
1697     }
1698
1699     for (Enumeration<NTuple<Descriptor>> e = GENSet.keys(); e.hasMoreElements();) {
1700       NTuple<Descriptor> key = e.nextElement();
1701
1702       Set<WriteAge> currWriteAgeSet = curr.get(key);
1703       if (currWriteAgeSet == null) {
1704         currWriteAgeSet = new HashSet<WriteAge>();
1705         curr.put(key, currWriteAgeSet);
1706       }
1707       currWriteAgeSet.addAll(GENSet.get(key));
1708     }
1709
1710   }
1711
1712   private void computeGENSetForWrite(NTuple<Descriptor> fldHeapPath,
1713       Hashtable<NTuple<Descriptor>, Set<WriteAge>> GENSet) {
1714
1715     // generate write age 0 for the field being written to
1716     Set<WriteAge> writeAgeSet = new HashSet<WriteAge>();
1717     writeAgeSet.add(new WriteAge(0));
1718     GENSet.put(fldHeapPath, writeAgeSet);
1719
1720   }
1721
1722   private void computeKILLSetForWrite(Hashtable<NTuple<Descriptor>, Set<WriteAge>> curr,
1723       NTuple<Descriptor> hp, Hashtable<NTuple<Descriptor>, Set<WriteAge>> KILLSet) {
1724
1725     // removes all of heap path that starts with prefix 'hp'
1726     // since any reference overwrite along heap path gives overwriting side
1727     // effects on the value
1728
1729     Set<NTuple<Descriptor>> keySet = curr.keySet();
1730     for (Iterator<NTuple<Descriptor>> iter = keySet.iterator(); iter.hasNext();) {
1731       NTuple<Descriptor> key = iter.next();
1732       if (key.startsWith(hp)) {
1733         KILLSet.put(key, curr.get(key));
1734       }
1735     }
1736
1737   }
1738
1739   private void bindHeapPathCallerArgWithCalleeParam(FlatCall fc) {
1740     // compute all possible callee set
1741     // transform all READ/WRITE set from the any possible
1742     // callees to the caller
1743     calleeUnionBoundReadSet.clear();
1744     calleeIntersectBoundMustWriteSet.clear();
1745     calleeUnionBoundMayWriteSet.clear();
1746
1747     if (ssjava.isSSJavaUtil(fc.getMethod().getClassDesc())) {
1748       // ssjava util case!
1749       // have write effects on the first argument
1750       TempDescriptor arg = fc.getArg(0);
1751       NTuple<Descriptor> argHeapPath = computePath(arg);
1752       calleeIntersectBoundMustWriteSet.add(argHeapPath);
1753       calleeUnionBoundMayWriteSet.add(argHeapPath);
1754     } else {
1755       MethodDescriptor mdCallee = fc.getMethod();
1756       Set<MethodDescriptor> setPossibleCallees = new HashSet<MethodDescriptor>();
1757       setPossibleCallees.addAll(callGraph.getMethods(mdCallee));
1758
1759       // create mapping from arg idx to its heap paths
1760       Hashtable<Integer, NTuple<Descriptor>> mapArgIdx2CallerArgHeapPath =
1761           new Hashtable<Integer, NTuple<Descriptor>>();
1762
1763       // arg idx is starting from 'this' arg
1764       if (fc.getThis() != null) {
1765         NTuple<Descriptor> thisHeapPath = mapHeapPath.get(fc.getThis());
1766         if (thisHeapPath == null) {
1767           // method is called without creating new flat node representing 'this'
1768           thisHeapPath = new NTuple<Descriptor>();
1769           thisHeapPath.add(fc.getThis());
1770         }
1771
1772         mapArgIdx2CallerArgHeapPath.put(Integer.valueOf(0), thisHeapPath);
1773       }
1774
1775       for (int i = 0; i < fc.numArgs(); i++) {
1776         TempDescriptor arg = fc.getArg(i);
1777         NTuple<Descriptor> argHeapPath = computePath(arg);
1778         mapArgIdx2CallerArgHeapPath.put(Integer.valueOf(i + 1), argHeapPath);
1779       }
1780
1781       for (Iterator iterator = setPossibleCallees.iterator(); iterator.hasNext();) {
1782         MethodDescriptor callee = (MethodDescriptor) iterator.next();
1783         FlatMethod calleeFlatMethod = state.getMethodFlat(callee);
1784
1785         // binding caller's args and callee's params
1786
1787         Set<NTuple<Descriptor>> calleeReadSet = mapFlatMethodToReadSet.get(calleeFlatMethod);
1788         if (calleeReadSet == null) {
1789           calleeReadSet = new HashSet<NTuple<Descriptor>>();
1790           mapFlatMethodToReadSet.put(calleeFlatMethod, calleeReadSet);
1791         }
1792
1793         Set<NTuple<Descriptor>> calleeMustWriteSet =
1794             mapFlatMethodToMustWriteSet.get(calleeFlatMethod);
1795
1796         if (calleeMustWriteSet == null) {
1797           calleeMustWriteSet = new HashSet<NTuple<Descriptor>>();
1798           mapFlatMethodToMustWriteSet.put(calleeFlatMethod, calleeMustWriteSet);
1799         }
1800
1801         Set<NTuple<Descriptor>> calleeMayWriteSet =
1802             mapFlatMethodToMayWriteSet.get(calleeFlatMethod);
1803
1804         if (calleeMayWriteSet == null) {
1805           calleeMayWriteSet = new HashSet<NTuple<Descriptor>>();
1806           mapFlatMethodToMayWriteSet.put(calleeFlatMethod, calleeMayWriteSet);
1807         }
1808
1809         Hashtable<Integer, TempDescriptor> mapParamIdx2ParamTempDesc =
1810             new Hashtable<Integer, TempDescriptor>();
1811         int offset = 0;
1812         if (calleeFlatMethod.getMethod().isStatic()) {
1813           // static method does not have implicit 'this' arg
1814           offset = 1;
1815         }
1816         for (int i = 0; i < calleeFlatMethod.numParameters(); i++) {
1817           TempDescriptor param = calleeFlatMethod.getParameter(i);
1818           mapParamIdx2ParamTempDesc.put(Integer.valueOf(i + offset), param);
1819         }
1820
1821         Set<NTuple<Descriptor>> calleeBoundReadSet =
1822             bindSet(calleeReadSet, mapParamIdx2ParamTempDesc, mapArgIdx2CallerArgHeapPath);
1823         // union of the current read set and the current callee's
1824         // read set
1825         calleeUnionBoundReadSet.addAll(calleeBoundReadSet);
1826
1827         Set<NTuple<Descriptor>> calleeBoundMustWriteSet =
1828             bindSet(calleeMustWriteSet, mapParamIdx2ParamTempDesc, mapArgIdx2CallerArgHeapPath);
1829         // intersection of the current overwrite set and the current
1830         // callee's
1831         // overwrite set
1832         merge(calleeIntersectBoundMustWriteSet, calleeBoundMustWriteSet);
1833
1834         Set<NTuple<Descriptor>> boundWriteSetFromCallee =
1835             bindSet(calleeMayWriteSet, mapParamIdx2ParamTempDesc, mapArgIdx2CallerArgHeapPath);
1836         calleeUnionBoundMayWriteSet.addAll(boundWriteSetFromCallee);
1837       }
1838
1839     }
1840
1841   }
1842
1843   private void bindHeapPathCallerArgWithCaleeParamForSharedLoc(MethodDescriptor mdCaller,
1844       FlatCall fc) {
1845
1846     calleeIntersectBoundSharedSet.clear();
1847     calleeUnionBoundDeleteSet.clear();
1848
1849     // if arg is not primitive type, we need to propagate maywritten set to
1850     // the caller's location path
1851
1852     MethodDescriptor mdCallee = fc.getMethod();
1853     Set<MethodDescriptor> setPossibleCallees = new HashSet<MethodDescriptor>();
1854     setPossibleCallees.addAll(callGraph.getMethods(mdCallee));
1855
1856     // create mapping from arg idx to its heap paths
1857     Hashtable<Integer, NTuple<Descriptor>> mapArgIdx2CallerArgHeapPath =
1858         new Hashtable<Integer, NTuple<Descriptor>>();
1859
1860     // arg idx is starting from 'this' arg
1861     if (fc.getThis() != null) {
1862       NTuple<Descriptor> thisHeapPath = mapHeapPath.get(fc.getThis());
1863       if (thisHeapPath == null) {
1864         // method is called without creating new flat node representing 'this'
1865         thisHeapPath = new NTuple<Descriptor>();
1866         thisHeapPath.add(fc.getThis());
1867       }
1868
1869       mapArgIdx2CallerArgHeapPath.put(Integer.valueOf(0), thisHeapPath);
1870     }
1871
1872     for (int i = 0; i < fc.numArgs(); i++) {
1873       TempDescriptor arg = fc.getArg(i);
1874       NTuple<Descriptor> argHeapPath = computePath(arg);
1875       mapArgIdx2CallerArgHeapPath.put(Integer.valueOf(i + 1), argHeapPath);
1876     }
1877
1878     // create mapping from arg idx to its location paths
1879     Hashtable<Integer, NTuple<Location>> mapArgIdx2CallerAgLocationPath =
1880         new Hashtable<Integer, NTuple<Location>>();
1881
1882     // arg idx is starting from 'this' arg
1883     if (fc.getThis() != null) {
1884       NTuple<Location> thisLocationPath = deriveLocationTuple(mdCaller, fc.getThis());
1885       mapArgIdx2CallerAgLocationPath.put(Integer.valueOf(0), thisLocationPath);
1886     }
1887
1888     for (int i = 0; i < fc.numArgs(); i++) {
1889       TempDescriptor arg = fc.getArg(i);
1890       NTuple<Location> argLocationPath = deriveLocationTuple(mdCaller, arg);
1891       if (argLocationPath != null) {
1892         mapArgIdx2CallerAgLocationPath.put(Integer.valueOf(i + 1), argLocationPath);
1893       }
1894     }
1895
1896     for (Iterator iterator = setPossibleCallees.iterator(); iterator.hasNext();) {
1897       MethodDescriptor callee = (MethodDescriptor) iterator.next();
1898       FlatMethod calleeFlatMethod = state.getMethodFlat(callee);
1899
1900       // binding caller's args and callee's params
1901
1902       Hashtable<Integer, TempDescriptor> mapParamIdx2ParamTempDesc =
1903           new Hashtable<Integer, TempDescriptor>();
1904       int offset = 0;
1905       if (calleeFlatMethod.getMethod().isStatic()) {
1906         // static method does not have implicit 'this' arg
1907         offset = 1;
1908       }
1909       for (int i = 0; i < calleeFlatMethod.numParameters(); i++) {
1910         TempDescriptor param = calleeFlatMethod.getParameter(i);
1911         mapParamIdx2ParamTempDesc.put(Integer.valueOf(i + offset), param);
1912       }
1913
1914       Set<Integer> keySet = mapArgIdx2CallerAgLocationPath.keySet();
1915       for (Iterator iterator2 = keySet.iterator(); iterator2.hasNext();) {
1916         Integer idx = (Integer) iterator2.next();
1917         NTuple<Location> callerArgLocationPath = mapArgIdx2CallerAgLocationPath.get(idx);
1918         NTuple<Descriptor> callerArgHeapPath = mapArgIdx2CallerArgHeapPath.get(idx);
1919
1920         TempDescriptor calleeParam = mapParamIdx2ParamTempDesc.get(idx);
1921         NTuple<Location> calleeLocationPath = deriveLocationTuple(mdCallee, calleeParam);
1922         SharedLocMap calleeDeleteSet = mapFlatMethodToDeleteSet.get(calleeFlatMethod);
1923         SharedLocMap calleeSharedLocMap = mapFlatMethodToSharedLocMap.get(calleeFlatMethod);
1924
1925         if (calleeDeleteSet != null) {
1926           createNewMappingOfDeleteSet(callerArgLocationPath, callerArgHeapPath, calleeLocationPath,
1927               calleeDeleteSet);
1928         }
1929
1930         if (calleeSharedLocMap != null) {
1931           createNewMappingOfSharedSet(callerArgLocationPath, callerArgHeapPath, calleeLocationPath,
1932               calleeSharedLocMap);
1933         }
1934
1935       }
1936
1937     }
1938
1939   }
1940
1941   private void createNewMappingOfDeleteSet(NTuple<Location> callerArgLocationPath,
1942       NTuple<Descriptor> callerArgHeapPath, NTuple<Location> calleeLocationPath,
1943       SharedLocMap calleeDeleteSet) {
1944
1945     SharedLocMap calleeParamDeleteSet = calleeDeleteSet.getHeapPathStartedWith(calleeLocationPath);
1946
1947     Set<NTuple<Location>> keySet = calleeParamDeleteSet.keySet();
1948     for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
1949       NTuple<Location> calleeLocTupleKey = (NTuple<Location>) iterator.next();
1950       Set<NTuple<Descriptor>> heapPathSet = calleeParamDeleteSet.get(calleeLocTupleKey);
1951       for (Iterator iterator2 = heapPathSet.iterator(); iterator2.hasNext();) {
1952         NTuple<Descriptor> calleeHeapPath = (NTuple<Descriptor>) iterator2.next();
1953         calleeUnionBoundDeleteSet.addWrite(
1954             bindLocationPath(callerArgLocationPath, calleeLocTupleKey),
1955             bindHeapPath(callerArgHeapPath, calleeHeapPath));
1956       }
1957     }
1958
1959   }
1960
1961   private void createNewMappingOfSharedSet(NTuple<Location> callerArgLocationPath,
1962       NTuple<Descriptor> callerArgHeapPath, NTuple<Location> calleeLocationPath,
1963       SharedLocMap calleeSharedLocMap) {
1964
1965     SharedLocMap calleeParamSharedSet =
1966         calleeSharedLocMap.getHeapPathStartedWith(calleeLocationPath);
1967
1968     Set<NTuple<Location>> keySet = calleeParamSharedSet.keySet();
1969     for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
1970       NTuple<Location> calleeLocTupleKey = (NTuple<Location>) iterator.next();
1971       Set<NTuple<Descriptor>> heapPathSet = calleeParamSharedSet.get(calleeLocTupleKey);
1972       Set<NTuple<Descriptor>> boundHeapPathSet = new HashSet<NTuple<Descriptor>>();
1973       for (Iterator iterator2 = heapPathSet.iterator(); iterator2.hasNext();) {
1974         NTuple<Descriptor> calleeHeapPath = (NTuple<Descriptor>) iterator2.next();
1975         boundHeapPathSet.add(bindHeapPath(callerArgHeapPath, calleeHeapPath));
1976       }
1977       calleeIntersectBoundSharedSet.intersect(
1978           bindLocationPath(callerArgLocationPath, calleeLocTupleKey), boundHeapPathSet);
1979     }
1980
1981   }
1982
1983   private NTuple<Location> bindLocationPath(NTuple<Location> start, NTuple<Location> end) {
1984     NTuple<Location> locPath = new NTuple<Location>();
1985     locPath.addAll(start);
1986     for (int i = 1; i < end.size(); i++) {
1987       locPath.add(end.get(i));
1988     }
1989     return locPath;
1990   }
1991
1992   private NTuple<Descriptor> bindHeapPath(NTuple<Descriptor> start, NTuple<Descriptor> end) {
1993     NTuple<Descriptor> heapPath = new NTuple<Descriptor>();
1994     heapPath.addAll(start);
1995     for (int i = 1; i < end.size(); i++) {
1996       heapPath.add(end.get(i));
1997     }
1998     return heapPath;
1999   }
2000
2001   private void initialize() {
2002     // First, identify ssjava loop entrace
2003
2004     // no need to analyze method having ssjava loop
2005     methodContainingSSJavaLoop = ssjava.getMethodContainingSSJavaLoop();
2006
2007     FlatMethod fm = state.getMethodFlat(methodContainingSSJavaLoop);
2008     Set<FlatNode> flatNodesToVisit = new HashSet<FlatNode>();
2009     flatNodesToVisit.add(fm);
2010
2011     LoopFinder loopFinder = new LoopFinder(fm);
2012
2013     while (!flatNodesToVisit.isEmpty()) {
2014       FlatNode fn = flatNodesToVisit.iterator().next();
2015       flatNodesToVisit.remove(fn);
2016
2017       String label = (String) state.fn2labelMap.get(fn);
2018       if (label != null) {
2019
2020         if (label.equals(ssjava.SSJAVA)) {
2021           ssjava.setSSJavaLoopEntrance(fn);
2022           break;
2023         }
2024       }
2025
2026       for (int i = 0; i < fn.numNext(); i++) {
2027         FlatNode nn = fn.getNext(i);
2028         flatNodesToVisit.add(nn);
2029       }
2030     }
2031
2032     assert ssjava.getSSJavaLoopEntrance() != null;
2033
2034     // assume that ssjava loop is top-level loop in method, not nested loop
2035     Set nestedLoop = loopFinder.nestedLoops();
2036     for (Iterator loopIter = nestedLoop.iterator(); loopIter.hasNext();) {
2037       LoopFinder lf = (LoopFinder) loopIter.next();
2038       if (lf.loopEntrances().iterator().next().equals(ssjava.getSSJavaLoopEntrance())) {
2039         ssjavaLoop = lf;
2040       }
2041     }
2042
2043     assert ssjavaLoop != null;
2044
2045     loopIncElements = (Set<FlatNode>) ssjavaLoop.loopIncElements();
2046
2047     // perform topological sort over the set of methods accessed by the main
2048     // event loop
2049     Set<MethodDescriptor> methodDescriptorsToAnalyze = new HashSet<MethodDescriptor>();
2050     methodDescriptorsToAnalyze.addAll(ssjava.getAnnotationRequireSet());
2051     sortedDescriptors = topologicalSort(methodDescriptorsToAnalyze);
2052   }
2053
2054   private void methodReadWriteSetAnalysis() {
2055     // perform method READ/OVERWRITE analysis
2056     LinkedList<MethodDescriptor> descriptorListToAnalyze =
2057         (LinkedList<MethodDescriptor>) sortedDescriptors.clone();
2058
2059     // current descriptors to visit in fixed-point interprocedural analysis,
2060     // prioritized by
2061     // dependency in the call graph
2062     methodDescriptorsToVisitStack.clear();
2063
2064     descriptorListToAnalyze.removeFirst();
2065
2066     Set<MethodDescriptor> methodDescriptorToVistSet = new HashSet<MethodDescriptor>();
2067     methodDescriptorToVistSet.addAll(descriptorListToAnalyze);
2068
2069     while (!descriptorListToAnalyze.isEmpty()) {
2070       MethodDescriptor md = descriptorListToAnalyze.removeFirst();
2071       methodDescriptorsToVisitStack.add(md);
2072     }
2073
2074     // analyze scheduled methods until there are no more to visit
2075     while (!methodDescriptorsToVisitStack.isEmpty()) {
2076       // start to analyze leaf node
2077       MethodDescriptor md = methodDescriptorsToVisitStack.pop();
2078       FlatMethod fm = state.getMethodFlat(md);
2079
2080       Set<NTuple<Descriptor>> readSet = new HashSet<NTuple<Descriptor>>();
2081       Set<NTuple<Descriptor>> mustWriteSet = new HashSet<NTuple<Descriptor>>();
2082       Set<NTuple<Descriptor>> mayWriteSet = new HashSet<NTuple<Descriptor>>();
2083
2084       methodReadWriteSet_analyzeMethod(fm, readSet, mustWriteSet, mayWriteSet);
2085
2086       Set<NTuple<Descriptor>> prevRead = mapFlatMethodToReadSet.get(fm);
2087       Set<NTuple<Descriptor>> prevMustWrite = mapFlatMethodToMustWriteSet.get(fm);
2088       Set<NTuple<Descriptor>> prevMayWrite = mapFlatMethodToMayWriteSet.get(fm);
2089
2090       if (!(readSet.equals(prevRead) && mustWriteSet.equals(prevMustWrite) && mayWriteSet
2091           .equals(prevMayWrite))) {
2092         mapFlatMethodToReadSet.put(fm, readSet);
2093         mapFlatMethodToMustWriteSet.put(fm, mustWriteSet);
2094         mapFlatMethodToMayWriteSet.put(fm, mayWriteSet);
2095
2096         // results for callee changed, so enqueue dependents caller for
2097         // further
2098         // analysis
2099         Iterator<MethodDescriptor> depsItr = getDependents(md).iterator();
2100         while (depsItr.hasNext()) {
2101           MethodDescriptor methodNext = depsItr.next();
2102           if (!methodDescriptorsToVisitStack.contains(methodNext)
2103               && methodDescriptorToVistSet.contains(methodNext)) {
2104             methodDescriptorsToVisitStack.add(methodNext);
2105           }
2106
2107         }
2108
2109       }
2110
2111     }
2112
2113     methodReadWriteSetAnalysisToEventLoopBody();
2114
2115   }
2116
2117   private void methodReadWriteSet_analyzeMethod(FlatMethod fm, Set<NTuple<Descriptor>> readSet,
2118       Set<NTuple<Descriptor>> mustWriteSet, Set<NTuple<Descriptor>> mayWriteSet) {
2119     if (state.SSJAVADEBUG) {
2120       System.out.println("SSJAVA: Definitely written Analyzing: " + fm);
2121     }
2122
2123     methodReadWriteSet_analyzeBody(fm, readSet, mustWriteSet, mayWriteSet, false);
2124
2125   }
2126
2127   private void methodReadWriteSetAnalysisToEventLoopBody() {
2128
2129     // perform method read/write analysis for Event Loop Body
2130
2131     FlatMethod flatMethodContainingSSJavaLoop = state.getMethodFlat(methodContainingSSJavaLoop);
2132
2133     if (state.SSJAVADEBUG) {
2134       System.out.println("SSJAVA: Definitely written Event Loop Analyzing: "
2135           + flatMethodContainingSSJavaLoop);
2136     }
2137
2138     Set<NTuple<Descriptor>> readSet = new HashSet<NTuple<Descriptor>>();
2139     Set<NTuple<Descriptor>> mustWriteSet = new HashSet<NTuple<Descriptor>>();
2140     Set<NTuple<Descriptor>> mayWriteSet = new HashSet<NTuple<Descriptor>>();
2141
2142     mapFlatMethodToReadSet.put(flatMethodContainingSSJavaLoop, readSet);
2143     mapFlatMethodToMustWriteSet.put(flatMethodContainingSSJavaLoop, mustWriteSet);
2144     mapFlatMethodToMayWriteSet.put(flatMethodContainingSSJavaLoop, mayWriteSet);
2145
2146     methodReadWriteSet_analyzeBody(ssjava.getSSJavaLoopEntrance(), readSet, mustWriteSet,
2147         mayWriteSet, true);
2148
2149   }
2150
2151   private void methodReadWriteSet_analyzeBody(FlatNode startNode, Set<NTuple<Descriptor>> readSet,
2152       Set<NTuple<Descriptor>> mustWriteSet, Set<NTuple<Descriptor>> mayWriteSet,
2153       boolean isEventLoopBody) {
2154
2155     // intraprocedural analysis
2156     Set<FlatNode> flatNodesToVisit = new HashSet<FlatNode>();
2157     flatNodesToVisit.add(startNode);
2158
2159     while (!flatNodesToVisit.isEmpty()) {
2160       FlatNode fn = flatNodesToVisit.iterator().next();
2161       flatNodesToVisit.remove(fn);
2162
2163       Set<NTuple<Descriptor>> currMustWriteSet = new HashSet<NTuple<Descriptor>>();
2164
2165       for (int i = 0; i < fn.numPrev(); i++) {
2166         FlatNode prevFn = fn.getPrev(i);
2167         Set<NTuple<Descriptor>> in = mapFlatNodeToMustWriteSet.get(prevFn);
2168         if (in != null) {
2169           merge(currMustWriteSet, in);
2170         }
2171       }
2172
2173       methodReadWriteSet_nodeActions(fn, currMustWriteSet, readSet, mustWriteSet, mayWriteSet,
2174           isEventLoopBody);
2175
2176       Set<NTuple<Descriptor>> mustSetPrev = mapFlatNodeToMustWriteSet.get(fn);
2177
2178       if (!currMustWriteSet.equals(mustSetPrev)) {
2179         mapFlatNodeToMustWriteSet.put(fn, currMustWriteSet);
2180         for (int i = 0; i < fn.numNext(); i++) {
2181           FlatNode nn = fn.getNext(i);
2182           if ((!isEventLoopBody) || loopIncElements.contains(nn)) {
2183             flatNodesToVisit.add(nn);
2184           }
2185
2186         }
2187       }
2188
2189     }
2190
2191   }
2192
2193   private void methodReadWriteSet_nodeActions(FlatNode fn,
2194       Set<NTuple<Descriptor>> currMustWriteSet, Set<NTuple<Descriptor>> readSet,
2195       Set<NTuple<Descriptor>> mustWriteSet, Set<NTuple<Descriptor>> mayWriteSet,
2196       boolean isEventLoopBody) {
2197
2198     TempDescriptor lhs;
2199     TempDescriptor rhs;
2200     FieldDescriptor fld;
2201
2202     switch (fn.kind()) {
2203     case FKind.FlatMethod: {
2204
2205       // set up initial heap paths for method parameters
2206       FlatMethod fm = (FlatMethod) fn;
2207       for (int i = 0; i < fm.numParameters(); i++) {
2208         TempDescriptor param = fm.getParameter(i);
2209         NTuple<Descriptor> heapPath = new NTuple<Descriptor>();
2210         heapPath.add(param);
2211         mapHeapPath.put(param, heapPath);
2212       }
2213     }
2214       break;
2215
2216     case FKind.FlatOpNode: {
2217       FlatOpNode fon = (FlatOpNode) fn;
2218       // for a normal assign node, need to propagate lhs's heap path to
2219       // rhs
2220
2221       if (fon.getOp().getOp() == Operation.ASSIGN) {
2222         rhs = fon.getLeft();
2223         lhs = fon.getDest();
2224
2225         NTuple<Descriptor> rhsHeapPath = mapHeapPath.get(rhs);
2226
2227         if (lhs.getType().isPrimitive()) {
2228           NTuple<Descriptor> lhsHeapPath = new NTuple<Descriptor>();
2229           lhsHeapPath.add(lhs);
2230           mapHeapPath.put(lhs, lhsHeapPath);
2231         } else if (rhsHeapPath != null) {
2232           mapHeapPath.put(lhs, mapHeapPath.get(rhs));
2233         } else {
2234           NTuple<Descriptor> heapPath = new NTuple<Descriptor>();
2235           heapPath.add(rhs);
2236           mapHeapPath.put(lhs, heapPath);
2237         }
2238
2239         // shared loc extension
2240         if (isEventLoopBody) {
2241           if (!lhs.getSymbol().startsWith("neverused") && rhs.getType().isImmutable()) {
2242
2243             if (rhs.getType().getExtension() instanceof Location
2244                 && lhs.getType().getExtension() instanceof CompositeLocation) {
2245               // rhs is field!
2246               Location rhsLoc = (Location) rhs.getType().getExtension();
2247
2248               CompositeLocation lhsCompLoc = (CompositeLocation) lhs.getType().getExtension();
2249               Location dstLoc = lhsCompLoc.get(lhsCompLoc.getSize() - 1);
2250
2251               NTuple<Descriptor> heapPath = new NTuple<Descriptor>();
2252               for (int i = 0; i < rhsHeapPath.size() - 1; i++) {
2253                 heapPath.add(rhsHeapPath.get(i));
2254               }
2255
2256               NTuple<Descriptor> writeHeapPath = new NTuple<Descriptor>();
2257               writeHeapPath.addAll(heapPath);
2258               writeHeapPath.add(lhs);
2259
2260             }
2261           }
2262         }
2263
2264       }
2265     }
2266       break;
2267
2268     case FKind.FlatElementNode:
2269     case FKind.FlatFieldNode: {
2270
2271       // x=y.f;
2272
2273       if (fn.kind() == FKind.FlatFieldNode) {
2274         FlatFieldNode ffn = (FlatFieldNode) fn;
2275         lhs = ffn.getDst();
2276         rhs = ffn.getSrc();
2277         fld = ffn.getField();
2278       } else {
2279         FlatElementNode fen = (FlatElementNode) fn;
2280         lhs = fen.getDst();
2281         rhs = fen.getSrc();
2282         TypeDescriptor td = rhs.getType().dereference();
2283         fld = getArrayField(td);
2284       }
2285
2286       if (fld.isFinal()) {
2287         // if field is final no need to check
2288         break;
2289       }
2290
2291       // set up heap path
2292       NTuple<Descriptor> srcHeapPath = mapHeapPath.get(rhs);
2293       if (srcHeapPath != null) {
2294         // if lhs srcHeapPath is null, it means that it is not reachable from
2295         // callee's parameters. so just ignore it
2296
2297         NTuple<Descriptor> readingHeapPath = new NTuple<Descriptor>(srcHeapPath.getList());
2298         readingHeapPath.add(fld);
2299         mapHeapPath.put(lhs, readingHeapPath);
2300
2301         // read (x.f)
2302         if (fld.getType().isImmutable()) {
2303           // if WT doesnot have hp(x.f), add hp(x.f) to READ
2304           if (!currMustWriteSet.contains(readingHeapPath)) {
2305             readSet.add(readingHeapPath);
2306           }
2307         }
2308
2309         // no need to kill hp(x.f) from WT
2310       }
2311
2312     }
2313       break;
2314
2315     case FKind.FlatSetFieldNode:
2316     case FKind.FlatSetElementNode: {
2317
2318       // x.f=y;
2319
2320       if (fn.kind() == FKind.FlatSetFieldNode) {
2321         FlatSetFieldNode fsfn = (FlatSetFieldNode) fn;
2322         lhs = fsfn.getDst();
2323         fld = fsfn.getField();
2324         rhs = fsfn.getSrc();
2325       } else {
2326         FlatSetElementNode fsen = (FlatSetElementNode) fn;
2327         lhs = fsen.getDst();
2328         rhs = fsen.getSrc();
2329         TypeDescriptor td = lhs.getType().dereference();
2330         fld = getArrayField(td);
2331       }
2332
2333       // set up heap path
2334       NTuple<Descriptor> lhsHeapPath = mapHeapPath.get(lhs);
2335
2336       if (lhsHeapPath != null) {
2337         // if lhs heap path is null, it means that it is not reachable from
2338         // callee's parameters. so just ignore it
2339         NTuple<Descriptor> fldHeapPath = new NTuple<Descriptor>(lhsHeapPath.getList());
2340         fldHeapPath.add(fld);
2341         mapHeapPath.put(fld, fldHeapPath);
2342
2343         // write(x.f)
2344         // need to add hp(y) to WT
2345         currMustWriteSet.add(fldHeapPath);
2346         mayWriteSet.add(fldHeapPath);
2347
2348       }
2349
2350     }
2351       break;
2352
2353     case FKind.FlatCall: {
2354
2355       FlatCall fc = (FlatCall) fn;
2356
2357       bindHeapPathCallerArgWithCalleeParam(fc);
2358
2359       Set<NTuple<Descriptor>> boundReadSet = new HashSet<NTuple<Descriptor>>();
2360       boundReadSet.addAll(calleeUnionBoundReadSet);
2361
2362       Set<NTuple<Descriptor>> boundMustWriteSet = new HashSet<NTuple<Descriptor>>();
2363       boundMustWriteSet.addAll(calleeIntersectBoundMustWriteSet);
2364
2365       Set<NTuple<Descriptor>> boundMayWriteSet = new HashSet<NTuple<Descriptor>>();
2366       boundMayWriteSet.addAll(calleeUnionBoundMayWriteSet);
2367
2368       mapFlatNodeToBoundReadSet.put(fn, boundReadSet);
2369       mapFlatNodeToBoundMustWriteSet.put(fn, boundMustWriteSet);
2370       mapFlatNodeToBoundMayWriteSet.put(fn, boundMayWriteSet);
2371
2372       // add heap path, which is an element of READ_bound set and is not
2373       // an
2374       // element of WT set, to the caller's READ set
2375       for (Iterator iterator = calleeUnionBoundReadSet.iterator(); iterator.hasNext();) {
2376         NTuple<Descriptor> read = (NTuple<Descriptor>) iterator.next();
2377         if (!currMustWriteSet.contains(read)) {
2378           readSet.add(read);
2379         }
2380       }
2381
2382       // add heap path, which is an element of OVERWRITE_bound set, to the
2383       // caller's WT set
2384       for (Iterator iterator = calleeIntersectBoundMustWriteSet.iterator(); iterator.hasNext();) {
2385         NTuple<Descriptor> write = (NTuple<Descriptor>) iterator.next();
2386         currMustWriteSet.add(write);
2387       }
2388
2389       // add heap path, which is an element of WRITE_BOUND set, to the
2390       // caller's writeSet
2391       for (Iterator iterator = calleeUnionBoundMayWriteSet.iterator(); iterator.hasNext();) {
2392         NTuple<Descriptor> write = (NTuple<Descriptor>) iterator.next();
2393         mayWriteSet.add(write);
2394       }
2395
2396     }
2397       break;
2398
2399     case FKind.FlatExit: {
2400       // merge the current written set with OVERWRITE set
2401       merge(mustWriteSet, currMustWriteSet);
2402     }
2403       break;
2404
2405     }
2406
2407   }
2408
2409   static public FieldDescriptor getArrayField(TypeDescriptor td) {
2410     FieldDescriptor fd = mapTypeToArrayField.get(td);
2411     if (fd == null) {
2412       fd =
2413           new FieldDescriptor(new Modifiers(Modifiers.PUBLIC), td, arrayElementFieldName, null,
2414               false);
2415       mapTypeToArrayField.put(td, fd);
2416     }
2417     return fd;
2418   }
2419
2420   private void merge(Set<NTuple<Descriptor>> curr, Set<NTuple<Descriptor>> in) {
2421     if (curr.isEmpty()) {
2422       // set has a special initial value which covers all possible
2423       // elements
2424       // For the first time of intersection, we can take all previous set
2425       curr.addAll(in);
2426     } else {
2427       // otherwise, current set is the intersection of the two sets
2428       curr.retainAll(in);
2429     }
2430
2431   }
2432
2433   // combine two heap path
2434   private NTuple<Descriptor> combine(NTuple<Descriptor> callerIn, NTuple<Descriptor> calleeIn) {
2435     NTuple<Descriptor> combined = new NTuple<Descriptor>();
2436
2437     for (int i = 0; i < callerIn.size(); i++) {
2438       combined.add(callerIn.get(i));
2439     }
2440
2441     // the first element of callee's heap path represents parameter
2442     // so we skip the first one since it is already added from caller's heap
2443     // path
2444     for (int i = 1; i < calleeIn.size(); i++) {
2445       combined.add(calleeIn.get(i));
2446     }
2447
2448     return combined;
2449   }
2450
2451   private Set<NTuple<Descriptor>> bindSet(Set<NTuple<Descriptor>> calleeSet,
2452       Hashtable<Integer, TempDescriptor> mapParamIdx2ParamTempDesc,
2453       Hashtable<Integer, NTuple<Descriptor>> mapCallerArgIdx2HeapPath) {
2454
2455     Set<NTuple<Descriptor>> boundedCalleeSet = new HashSet<NTuple<Descriptor>>();
2456
2457     Set<Integer> keySet = mapCallerArgIdx2HeapPath.keySet();
2458     for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
2459       Integer idx = (Integer) iterator.next();
2460
2461       NTuple<Descriptor> callerArgHeapPath = mapCallerArgIdx2HeapPath.get(idx);
2462       TempDescriptor calleeParam = mapParamIdx2ParamTempDesc.get(idx);
2463       for (Iterator iterator2 = calleeSet.iterator(); iterator2.hasNext();) {
2464         NTuple<Descriptor> element = (NTuple<Descriptor>) iterator2.next();
2465         if (element.startsWith(calleeParam)) {
2466           NTuple<Descriptor> boundElement = combine(callerArgHeapPath, element);
2467           boundedCalleeSet.add(boundElement);
2468         }
2469
2470       }
2471
2472     }
2473     return boundedCalleeSet;
2474
2475   }
2476
2477   // Borrowed it from disjoint analysis
2478   private LinkedList<MethodDescriptor> topologicalSort(Set<MethodDescriptor> toSort) {
2479
2480     Set<MethodDescriptor> discovered = new HashSet<MethodDescriptor>();
2481
2482     LinkedList<MethodDescriptor> sorted = new LinkedList<MethodDescriptor>();
2483
2484     Iterator<MethodDescriptor> itr = toSort.iterator();
2485     while (itr.hasNext()) {
2486       MethodDescriptor d = itr.next();
2487
2488       if (!discovered.contains(d)) {
2489         dfsVisit(d, toSort, sorted, discovered);
2490       }
2491     }
2492
2493     return sorted;
2494   }
2495
2496   // While we're doing DFS on call graph, remember
2497   // dependencies for efficient queuing of methods
2498   // during interprocedural analysis:
2499   //
2500   // a dependent of a method decriptor d for this analysis is:
2501   // 1) a method or task that invokes d
2502   // 2) in the descriptorsToAnalyze set
2503   private void dfsVisit(MethodDescriptor md, Set<MethodDescriptor> toSort,
2504       LinkedList<MethodDescriptor> sorted, Set<MethodDescriptor> discovered) {
2505
2506     discovered.add(md);
2507
2508     Iterator itr = callGraph.getCallerSet(md).iterator();
2509     while (itr.hasNext()) {
2510       MethodDescriptor dCaller = (MethodDescriptor) itr.next();
2511       // only consider callers in the original set to analyze
2512       if (!toSort.contains(dCaller)) {
2513         continue;
2514       }
2515       if (!discovered.contains(dCaller)) {
2516         addDependent(md, // callee
2517             dCaller // caller
2518         );
2519
2520         dfsVisit(dCaller, toSort, sorted, discovered);
2521       }
2522     }
2523
2524     // for leaf-nodes last now!
2525     sorted.addLast(md);
2526   }
2527
2528   // a dependent of a method decriptor d for this analysis is:
2529   // 1) a method or task that invokes d
2530   // 2) in the descriptorsToAnalyze set
2531   private void addDependent(MethodDescriptor callee, MethodDescriptor caller) {
2532     Set<MethodDescriptor> deps = mapDescriptorToSetDependents.get(callee);
2533     if (deps == null) {
2534       deps = new HashSet<MethodDescriptor>();
2535     }
2536     deps.add(caller);
2537     mapDescriptorToSetDependents.put(callee, deps);
2538   }
2539
2540   private Set<MethodDescriptor> getDependents(MethodDescriptor callee) {
2541     Set<MethodDescriptor> deps = mapDescriptorToSetDependents.get(callee);
2542     if (deps == null) {
2543       deps = new HashSet<MethodDescriptor>();
2544       mapDescriptorToSetDependents.put(callee, deps);
2545     }
2546     return deps;
2547   }
2548
2549   private NTuple<Descriptor> computePath(Descriptor td) {
2550     // generate proper path fot input td
2551     // if td is local variable, it just generate one element tuple path
2552     if (mapHeapPath.containsKey(td)) {
2553       NTuple<Descriptor> rtrHeapPath = new NTuple<Descriptor>();
2554       rtrHeapPath.addAll(mapHeapPath.get(td));
2555       return rtrHeapPath;
2556     } else {
2557       NTuple<Descriptor> rtrHeapPath = new NTuple<Descriptor>();
2558       rtrHeapPath.add(td);
2559       return rtrHeapPath;
2560     }
2561   }
2562
2563   private NTuple<Location> deriveThisLocationTuple(MethodDescriptor md) {
2564     String thisLocIdentifier = ssjava.getMethodLattice(md).getThisLoc();
2565     Location thisLoc = new Location(md, thisLocIdentifier);
2566     NTuple<Location> locTuple = new NTuple<Location>();
2567     locTuple.add(thisLoc);
2568     return locTuple;
2569   }
2570
2571   private NTuple<Location> deriveGlobalLocationTuple(MethodDescriptor md) {
2572     String globalLocIdentifier = ssjava.getMethodLattice(md).getGlobalLoc();
2573     Location globalLoc = new Location(md, globalLocIdentifier);
2574     NTuple<Location> locTuple = new NTuple<Location>();
2575     locTuple.add(globalLoc);
2576     return locTuple;
2577   }
2578
2579   private NTuple<Location> deriveLocationTuple(MethodDescriptor md, TempDescriptor td) {
2580
2581     assert td.getType() != null;
2582
2583     if (mapDescriptorToLocationPath.containsKey(td)) {
2584       NTuple<Location> locPath = mapDescriptorToLocationPath.get(td);
2585       NTuple<Location> rtrPath = new NTuple<Location>();
2586       rtrPath.addAll(locPath);
2587       return rtrPath;
2588     } else {
2589       if (td.getSymbol().startsWith("this")) {
2590         NTuple<Location> thisPath = deriveThisLocationTuple(md);
2591
2592         NTuple<Location> rtrPath = new NTuple<Location>();
2593         rtrPath.addAll(thisPath);
2594
2595         return rtrPath;
2596       } else {
2597
2598         if (td.getType().getExtension() != null) {
2599           SSJavaType ssJavaType = (SSJavaType) td.getType().getExtension();
2600           if (ssJavaType.getCompLoc() != null) {
2601             NTuple<Location> rtrPath = new NTuple<Location>();
2602             rtrPath.addAll(ssJavaType.getCompLoc().getTuple());
2603             return rtrPath;
2604           }
2605         }
2606
2607         return null;
2608
2609       }
2610     }
2611   }
2612 }