1 package Analysis.Disjoint;
3 import Analysis.CallGraph.*;
4 import Analysis.Liveness;
5 import Analysis.ArrayReferencees;
6 import Analysis.OoOJava.Accessible;
7 import Analysis.OoOJava.RBlockRelationAnalysis;
8 import Analysis.FlatIRGraph.*;
11 import IR.Tree.Modifiers;
16 public class DisjointAnalysis implements HeapAnalysis {
18 ///////////////////////////////////////////
20 // Public interface to discover possible
21 // sharing in the program under analysis
23 ///////////////////////////////////////////
25 // if an object allocated at the target site may be
26 // reachable from both an object from root1 and an
27 // object allocated at root2, return TRUE
28 public boolean mayBothReachTarget(FlatMethod fm,
33 AllocSite asr1 = getAllocationSiteFromFlatNew(fnRoot1);
34 AllocSite asr2 = getAllocationSiteFromFlatNew(fnRoot2);
35 assert asr1.isFlagged();
36 assert asr2.isFlagged();
38 AllocSite ast = getAllocationSiteFromFlatNew(fnTarget);
39 ReachGraph rg = getPartial(fm.getMethod() );
41 return rg.mayBothReachTarget(asr1, asr2, ast);
44 // similar to the method above, return TRUE if ever
45 // more than one object from the root allocation site
46 // may reach an object from the target site
47 public boolean mayManyReachTarget(FlatMethod fm,
51 AllocSite asr = getAllocationSiteFromFlatNew(fnRoot);
52 assert asr.isFlagged();
54 AllocSite ast = getAllocationSiteFromFlatNew(fnTarget);
55 ReachGraph rg = getPartial(fm.getMethod() );
57 return rg.mayManyReachTarget(asr, ast);
63 public HashSet<AllocSite>
64 getFlaggedAllocationSitesReachableFromTask(TaskDescriptor td) {
65 checkAnalysisComplete();
66 return getFlaggedAllocationSitesReachableFromTaskPRIVATE(td);
69 public AllocSite getAllocationSiteFromFlatNew(FlatNew fn) {
70 checkAnalysisComplete();
71 return getAllocSiteFromFlatNewPRIVATE(fn);
74 public AllocSite getAllocationSiteFromHeapRegionNodeID(Integer id) {
75 checkAnalysisComplete();
76 return mapHrnIdToAllocSite.get(id);
79 public Set<HeapRegionNode> hasPotentialSharing(Descriptor taskOrMethod,
82 checkAnalysisComplete();
83 ReachGraph rg=mapDescriptorToCompleteReachGraph.get(taskOrMethod);
84 FlatMethod fm=state.getMethodFlat(taskOrMethod);
86 return rg.mayReachSharedObjects(fm, paramIndex1, paramIndex2);
89 public Set<HeapRegionNode> hasPotentialSharing(Descriptor taskOrMethod,
90 int paramIndex, AllocSite alloc) {
91 checkAnalysisComplete();
92 ReachGraph rg = mapDescriptorToCompleteReachGraph.get(taskOrMethod);
93 FlatMethod fm=state.getMethodFlat(taskOrMethod);
95 return rg.mayReachSharedObjects(fm, paramIndex, alloc);
98 public Set<HeapRegionNode> hasPotentialSharing(Descriptor taskOrMethod,
99 AllocSite alloc, int paramIndex) {
100 checkAnalysisComplete();
101 ReachGraph rg = mapDescriptorToCompleteReachGraph.get(taskOrMethod);
102 FlatMethod fm=state.getMethodFlat(taskOrMethod);
104 return rg.mayReachSharedObjects(fm, paramIndex, alloc);
107 public Set<HeapRegionNode> hasPotentialSharing(Descriptor taskOrMethod,
108 AllocSite alloc1, AllocSite alloc2) {
109 checkAnalysisComplete();
110 ReachGraph rg = mapDescriptorToCompleteReachGraph.get(taskOrMethod);
112 return rg.mayReachSharedObjects(alloc1, alloc2);
115 public String prettyPrintNodeSet(Set<HeapRegionNode> s) {
116 checkAnalysisComplete();
120 Iterator<HeapRegionNode> i = s.iterator();
121 while (i.hasNext()) {
122 HeapRegionNode n = i.next();
124 AllocSite as = n.getAllocSite();
126 out += " " + n.toString() + ",\n";
128 out += " " + n.toString() + ": " + as.toStringVerbose()
137 // use the methods given above to check every possible sharing class
138 // between task parameters and flagged allocation sites reachable
140 public void writeAllSharing(String outputFile,
143 boolean tabularOutput,
146 throws java.io.IOException {
147 checkAnalysisComplete();
149 BufferedWriter bw = new BufferedWriter(new FileWriter(outputFile));
151 if (!tabularOutput) {
152 bw.write("Conducting ownership analysis with allocation depth = "
153 + allocationDepth + "\n");
154 bw.write(timeReport + "\n");
159 // look through every task for potential sharing
160 Iterator taskItr = state.getTaskSymbolTable().getDescriptorsIterator();
161 while (taskItr.hasNext()) {
162 TaskDescriptor td = (TaskDescriptor) taskItr.next();
164 if (!tabularOutput) {
165 bw.write("\n---------" + td + "--------\n");
168 HashSet<AllocSite> allocSites = getFlaggedAllocationSitesReachableFromTask(td);
170 Set<HeapRegionNode> common;
172 // for each task parameter, check for sharing classes with
173 // other task parameters and every allocation site
174 // reachable from this task
175 boolean foundSomeSharing = false;
177 FlatMethod fm = state.getMethodFlat(td);
178 for (int i = 0; i < fm.numParameters(); ++i) {
180 // skip parameters with types that cannot reference
182 if( !shouldAnalysisTrack(fm.getParameter(i).getType() ) ) {
186 // for the ith parameter check for sharing classes to all
187 // higher numbered parameters
188 for (int j = i + 1; j < fm.numParameters(); ++j) {
190 // skip parameters with types that cannot reference
192 if( !shouldAnalysisTrack(fm.getParameter(j).getType() ) ) {
197 common = hasPotentialSharing(td, i, j);
198 if (!common.isEmpty()) {
199 foundSomeSharing = true;
201 if (!tabularOutput) {
202 bw.write("Potential sharing between parameters " + i
203 + " and " + j + ".\n");
204 bw.write(prettyPrintNodeSet(common) + "\n");
209 // for the ith parameter, check for sharing classes against
210 // the set of allocation sites reachable from this
212 Iterator allocItr = allocSites.iterator();
213 while (allocItr.hasNext()) {
214 AllocSite as = (AllocSite) allocItr.next();
215 common = hasPotentialSharing(td, i, as);
216 if (!common.isEmpty()) {
217 foundSomeSharing = true;
219 if (!tabularOutput) {
220 bw.write("Potential sharing between parameter " + i
221 + " and " + as.getFlatNew() + ".\n");
222 bw.write(prettyPrintNodeSet(common) + "\n");
228 // for each allocation site check for sharing classes with
229 // other allocation sites in the context of execution
231 HashSet<AllocSite> outerChecked = new HashSet<AllocSite>();
232 Iterator allocItr1 = allocSites.iterator();
233 while (allocItr1.hasNext()) {
234 AllocSite as1 = (AllocSite) allocItr1.next();
236 Iterator allocItr2 = allocSites.iterator();
237 while (allocItr2.hasNext()) {
238 AllocSite as2 = (AllocSite) allocItr2.next();
240 if (!outerChecked.contains(as2)) {
241 common = hasPotentialSharing(td, as1, as2);
243 if (!common.isEmpty()) {
244 foundSomeSharing = true;
246 if (!tabularOutput) {
247 bw.write("Potential sharing between "
248 + as1.getFlatNew() + " and "
249 + as2.getFlatNew() + ".\n");
250 bw.write(prettyPrintNodeSet(common) + "\n");
256 outerChecked.add(as1);
259 if (!foundSomeSharing) {
260 if (!tabularOutput) {
261 bw.write("No sharing between flagged objects in Task " + td
269 bw.write(" & " + numSharing + " & " + justTime + " & " + numLines
270 + " & " + numMethodsAnalyzed() + " \\\\\n");
272 bw.write("\nNumber sharing classes: "+numSharing);
280 // this version of writeAllSharing is for Java programs that have no tasks
281 // ***********************************
282 // WARNING: THIS DOES NOT DO THE RIGHT THING, REPORTS 0 ALWAYS!
283 // It should use mayBothReachTarget and mayManyReachTarget like
284 // OoOJava does to query analysis results
285 // ***********************************
286 public void writeAllSharingJava(String outputFile,
289 boolean tabularOutput,
292 throws java.io.IOException {
293 checkAnalysisComplete();
299 BufferedWriter bw = new BufferedWriter(new FileWriter(outputFile));
301 bw.write("Conducting disjoint reachability analysis with allocation depth = "
302 + allocationDepth + "\n");
303 bw.write(timeReport + "\n\n");
305 boolean foundSomeSharing = false;
307 Descriptor d = typeUtil.getMain();
308 HashSet<AllocSite> allocSites = getFlaggedAllocationSites(d);
310 // for each allocation site check for sharing classes with
311 // other allocation sites in the context of execution
313 HashSet<AllocSite> outerChecked = new HashSet<AllocSite>();
314 Iterator allocItr1 = allocSites.iterator();
315 while (allocItr1.hasNext()) {
316 AllocSite as1 = (AllocSite) allocItr1.next();
318 Iterator allocItr2 = allocSites.iterator();
319 while (allocItr2.hasNext()) {
320 AllocSite as2 = (AllocSite) allocItr2.next();
322 if (!outerChecked.contains(as2)) {
323 Set<HeapRegionNode> common = hasPotentialSharing(d,
326 if (!common.isEmpty()) {
327 foundSomeSharing = true;
328 bw.write("Potential sharing between "
329 + as1.getDisjointAnalysisId() + " and "
330 + as2.getDisjointAnalysisId() + ".\n");
331 bw.write(prettyPrintNodeSet(common) + "\n");
337 outerChecked.add(as1);
340 if (!foundSomeSharing) {
341 bw.write("No sharing classes between flagged objects found.\n");
343 bw.write("\nNumber sharing classes: "+numSharing);
346 bw.write("Number of methods analyzed: "+numMethodsAnalyzed()+"\n");
353 public Alloc getCmdLineArgsAlloc() {
354 return getAllocationSiteFromFlatNew( constructedCmdLineArgsNew );
356 public Alloc getCmdLineArgAlloc() {
357 return getAllocationSiteFromFlatNew( constructedCmdLineArgNew );
359 public Alloc getCmdLineArgBytesAlloc() {
360 return getAllocationSiteFromFlatNew( constructedCmdLineArgBytesNew );
362 public Alloc getNewStringLiteralAlloc() {
363 return newStringLiteralAlloc;
365 public Alloc getNewStringLiteralBytesAlloc() {
366 return newStringLiteralBytesAlloc;
369 ///////////////////////////////////////////
371 // end public interface
373 ///////////////////////////////////////////
377 protected void checkAnalysisComplete() {
378 if( !analysisComplete ) {
379 throw new Error("Warning: public interface method called while analysis is running.");
388 // run in faster mode, only when bugs wrung out!
389 public static boolean releaseMode;
391 // use command line option to set this, analysis
392 // should attempt to be deterministic
393 public static boolean determinismDesired;
395 // when we want to enforce determinism in the
396 // analysis we need to sort descriptors rather
397 // than toss them in efficient sets, use this
398 public static DescriptorComparator dComp =
399 new DescriptorComparator();
402 // data from the compiler
404 public CallGraph callGraph;
405 public Liveness liveness;
406 public ArrayReferencees arrayReferencees;
407 public RBlockRelationAnalysis rblockRel;
408 public TypeUtil typeUtil;
409 public int allocationDepth;
411 protected boolean doEffectsAnalysis = false;
412 protected EffectsAnalysis effectsAnalysis;
413 protected BuildStateMachines buildStateMachines;
415 protected boolean doDefiniteReachAnalysis = false;
416 protected DefiniteReachAnalysis definiteReachAnalysis;
419 // data structure for public interface
420 private Hashtable< Descriptor, HashSet<AllocSite> >
421 mapDescriptorToAllocSiteSet;
424 // for public interface methods to warn that they
425 // are grabbing results during analysis
426 private boolean analysisComplete;
429 // used to identify HeapRegionNode objects
430 // A unique ID equates an object in one
431 // ownership graph with an object in another
432 // graph that logically represents the same
434 // start at 10 and increment to reserve some
435 // IDs for special purposes
436 static protected int uniqueIDcount = 10;
439 // An out-of-scope method created by the
440 // analysis that has no parameters, and
441 // appears to allocate the command line
442 // arguments, then invoke the source code's
443 // main method. The purpose of this is to
444 // provide the analysis with an explicit
445 // top-level context with no parameters
446 protected MethodDescriptor mdAnalysisEntry;
447 protected FlatMethod fmAnalysisEntry;
449 // main method defined by source program
450 protected MethodDescriptor mdSourceEntry;
452 // the set of task and/or method descriptors
453 // reachable in call graph
454 protected Set<Descriptor>
455 descriptorsToAnalyze;
457 // current descriptors to visit in fixed-point
458 // interprocedural analysis, prioritized by
459 // dependency in the call graph
460 protected Stack<Descriptor>
461 descriptorsToVisitStack;
462 protected PriorityQueue<DescriptorQWrapper>
465 // a duplication of the above structure, but
466 // for efficient testing of inclusion
467 protected HashSet<Descriptor>
468 descriptorsToVisitSet;
470 // storage for priorities (doesn't make sense)
471 // to add it to the Descriptor class, just in
473 protected Hashtable<Descriptor, Integer>
474 mapDescriptorToPriority;
476 // when analyzing a method and scheduling more:
477 // remember set of callee's enqueued for analysis
478 // so they can be put on top of the callers in
479 // the stack-visit mode
480 protected Set<Descriptor>
483 // maps a descriptor to its current partial result
484 // from the intraprocedural fixed-point analysis--
485 // then the interprocedural analysis settles, this
486 // mapping will have the final results for each
488 protected Hashtable<Descriptor, ReachGraph>
489 mapDescriptorToCompleteReachGraph;
491 // maps a descriptor to its known dependents: namely
492 // methods or tasks that call the descriptor's method
493 // AND are part of this analysis (reachable from main)
494 protected Hashtable< Descriptor, Set<Descriptor> >
495 mapDescriptorToSetDependents;
497 // if the analysis client wants to flag allocation sites
498 // programmatically, it should provide a set of FlatNew
499 // statements--this may be null if unneeded
500 protected Set<FlatNew> sitesToFlag;
502 // maps each flat new to one analysis abstraction
503 // allocate site object, these exist outside reach graphs
504 protected Hashtable<FlatNew, AllocSite>
505 mapFlatNewToAllocSite;
507 // maps intergraph heap region IDs to intergraph
508 // allocation sites that created them, a redundant
509 // structure for efficiency in some operations
510 protected Hashtable<Integer, AllocSite>
513 // maps a method to its initial heap model (IHM) that
514 // is the set of reachability graphs from every caller
515 // site, all merged together. The reason that we keep
516 // them separate is that any one call site's contribution
517 // to the IHM may changed along the path to the fixed point
518 protected Hashtable< Descriptor, Hashtable< FlatCall, ReachGraph > >
519 mapDescriptorToIHMcontributions;
521 // additionally, keep a mapping from descriptors to the
522 // merged in-coming initial context, because we want this
523 // initial context to be STRICTLY MONOTONIC
524 protected Hashtable<Descriptor, ReachGraph>
525 mapDescriptorToInitialContext;
527 // mapping of current partial results for a given node. Note that
528 // to reanalyze a method we discard all partial results because a
529 // null reach graph indicates the node needs to be visited on the
530 // way to the fixed point.
531 // The reason for a persistent mapping is so after the analysis we
532 // can ask for the graph of any node at the fixed point, but this
533 // option is only enabled with a compiler flag.
534 protected Hashtable<FlatNode, ReachGraph> mapFlatNodeToReachGraphPersist;
535 protected Hashtable<FlatNode, ReachGraph> mapFlatNodeToReachGraph;
538 // make the result for back edges analysis-wide STRICTLY
539 // MONOTONIC as well, but notice we use FlatNode as the
540 // key for this map: in case we want to consider other
541 // nodes as back edge's in future implementations
542 protected Hashtable<FlatNode, ReachGraph>
543 mapBackEdgeToMonotone;
546 public static final String arrayElementFieldName = "___element_";
547 static protected Hashtable<TypeDescriptor, FieldDescriptor>
551 protected boolean suppressOutput;
553 // for controlling DOT file output
554 protected boolean writeFinalDOTs;
555 protected boolean writeAllIncrementalDOTs;
557 // supporting DOT output--when we want to write every
558 // partial method result, keep a tally for generating
560 protected Hashtable<Descriptor, Integer>
561 mapDescriptorToNumUpdates;
563 //map task descriptor to initial task parameter
564 protected Hashtable<Descriptor, ReachGraph>
565 mapDescriptorToReachGraph;
567 protected PointerMethod pm;
569 //Keeps track of all the reach graphs at every program point
570 //DO NOT USE UNLESS YOU REALLY NEED IT
571 static protected Hashtable<FlatNode, ReachGraph> fn2rgAtEnter =
572 new Hashtable<FlatNode, ReachGraph>();
574 static protected Hashtable<FlatNode, ReachGraph> fn2rgAtExit =
575 new Hashtable<FlatNode, ReachGraph>();
578 private Hashtable<FlatCall, Descriptor> fc2enclosing;
580 Accessible accessible;
583 // we construct an entry method of flat nodes complete
584 // with a new allocation site to model the command line
585 // args creation just for the analysis, so remember that
586 // allocation site. Later in code gen we might want to
587 // know if something is pointing-to to the cmd line args
588 // and we can verify by checking the allocation site field.
589 protected FlatNew constructedCmdLineArgsNew;
590 protected FlatNew constructedCmdLineArgNew;
591 protected FlatNew constructedCmdLineArgBytesNew;
593 // similar to above, the runtime allocates new strings
594 // for literal nodes, so make up an alloc to model that
595 protected AllocSite newStringLiteralAlloc;
596 protected AllocSite newStringLiteralBytesAlloc;
598 // both of the above need the descriptor of the field
599 // for the String's value field to reference by the
600 // byte array from the string object
601 protected TypeDescriptor stringType;
602 protected TypeDescriptor stringBytesType;
603 protected FieldDescriptor stringBytesField;
606 protected void initImplicitStringsModel() {
608 ClassDescriptor cdString = typeUtil.getClass( typeUtil.StringClass );
609 assert cdString != null;
613 new TypeDescriptor( cdString );
616 new TypeDescriptor(TypeDescriptor.CHAR).makeArray( state );
619 stringBytesField = null;
620 Iterator sFieldsItr = cdString.getFields();
621 while( sFieldsItr.hasNext() ) {
622 FieldDescriptor fd = (FieldDescriptor) sFieldsItr.next();
623 if( fd.getSymbol().equals( typeUtil.StringClassValueField ) ) {
624 stringBytesField = fd;
628 assert stringBytesField != null;
631 TempDescriptor throwAway1 =
632 new TempDescriptor("stringLiteralTemp_dummy1",
635 FlatNew fnStringLiteral =
636 new FlatNew(stringType,
640 newStringLiteralAlloc
641 = getAllocSiteFromFlatNewPRIVATE( fnStringLiteral );
644 TempDescriptor throwAway2 =
645 new TempDescriptor("stringLiteralTemp_dummy2",
648 FlatNew fnStringLiteralBytes =
649 new FlatNew(stringBytesType,
653 newStringLiteralBytesAlloc
654 = getAllocSiteFromFlatNewPRIVATE( fnStringLiteralBytes );
660 // allocate various structures that are not local
661 // to a single class method--should be done once
662 protected void allocateStructures() {
664 if( determinismDesired ) {
665 // use an ordered set
666 descriptorsToAnalyze = new TreeSet<Descriptor>(dComp);
668 // otherwise use a speedy hashset
669 descriptorsToAnalyze = new HashSet<Descriptor>();
672 mapDescriptorToCompleteReachGraph =
673 new Hashtable<Descriptor, ReachGraph>();
675 mapDescriptorToNumUpdates =
676 new Hashtable<Descriptor, Integer>();
678 mapDescriptorToSetDependents =
679 new Hashtable< Descriptor, Set<Descriptor> >();
681 mapFlatNewToAllocSite =
682 new Hashtable<FlatNew, AllocSite>();
684 mapDescriptorToIHMcontributions =
685 new Hashtable< Descriptor, Hashtable< FlatCall, ReachGraph > >();
687 mapDescriptorToInitialContext =
688 new Hashtable<Descriptor, ReachGraph>();
690 mapFlatNodeToReachGraphPersist =
691 new Hashtable<FlatNode, ReachGraph>();
693 mapBackEdgeToMonotone =
694 new Hashtable<FlatNode, ReachGraph>();
696 mapHrnIdToAllocSite =
697 new Hashtable<Integer, AllocSite>();
699 mapTypeToArrayField =
700 new Hashtable <TypeDescriptor, FieldDescriptor>();
702 if( state.DISJOINTDVISITSTACK ||
703 state.DISJOINTDVISITSTACKEESONTOP
705 descriptorsToVisitStack =
706 new Stack<Descriptor>();
709 if( state.DISJOINTDVISITPQUE ) {
710 descriptorsToVisitQ =
711 new PriorityQueue<DescriptorQWrapper>();
714 descriptorsToVisitSet =
715 new HashSet<Descriptor>();
717 mapDescriptorToPriority =
718 new Hashtable<Descriptor, Integer>();
721 new HashSet<Descriptor>();
723 mapDescriptorToAllocSiteSet =
724 new Hashtable<Descriptor, HashSet<AllocSite> >();
726 mapDescriptorToReachGraph =
727 new Hashtable<Descriptor, ReachGraph>();
729 fc2enclosing = new Hashtable<FlatCall, Descriptor>();
734 // this analysis generates a disjoint reachability
735 // graph for every reachable method in the program
736 public DisjointAnalysis(State s,
741 Set<FlatNew> sitesToFlag,
742 RBlockRelationAnalysis rra
744 init(s, tu, cg, l, ar, sitesToFlag, rra, null, false);
747 public DisjointAnalysis(State s,
752 Set<FlatNew> sitesToFlag,
753 RBlockRelationAnalysis rra,
754 boolean suppressOutput
756 init(s, tu, cg, l, ar, sitesToFlag, rra, null, suppressOutput);
759 public DisjointAnalysis(State s,
764 Set<FlatNew> sitesToFlag,
765 RBlockRelationAnalysis rra,
766 BuildStateMachines bsm,
767 boolean suppressOutput
769 init(s, tu, cg, l, ar, sitesToFlag, rra, bsm, suppressOutput);
772 protected void init(State state,
776 ArrayReferencees arrayReferencees,
777 Set<FlatNew> sitesToFlag,
778 RBlockRelationAnalysis rra,
779 BuildStateMachines bsm,
780 boolean suppressOutput
783 analysisComplete = false;
786 this.typeUtil = typeUtil;
787 this.callGraph = callGraph;
788 this.liveness = liveness;
789 this.arrayReferencees = arrayReferencees;
790 this.sitesToFlag = sitesToFlag;
791 this.rblockRel = rra;
792 this.suppressOutput = suppressOutput;
793 this.buildStateMachines = bsm;
795 if( rblockRel != null ) {
796 doEffectsAnalysis = true;
797 effectsAnalysis = new EffectsAnalysis();
799 EffectsAnalysis.state = state;
800 EffectsAnalysis.buildStateMachines = buildStateMachines;
802 //note: instead of reachgraph's isAccessible, using the result of accessible analysis
803 //since accessible gives us more accurate results
804 accessible=new Accessible(state, callGraph, rra, liveness);
805 accessible.doAnalysis();
808 this.allocationDepth = state.DISJOINTALLOCDEPTH;
809 this.releaseMode = state.DISJOINTRELEASEMODE;
810 this.determinismDesired = state.DISJOINTDETERMINISM;
812 this.writeFinalDOTs = state.DISJOINTWRITEDOTS && !state.DISJOINTWRITEALL;
813 this.writeAllIncrementalDOTs = state.DISJOINTWRITEDOTS && state.DISJOINTWRITEALL;
815 this.takeDebugSnapshots = state.DISJOINTSNAPSYMBOL != null;
816 this.descSymbolDebug = state.DISJOINTSNAPSYMBOL;
817 this.visitStartCapture = state.DISJOINTSNAPVISITTOSTART;
818 this.numVisitsToCapture = state.DISJOINTSNAPNUMVISITS;
819 this.stopAfterCapture = state.DISJOINTSNAPSTOPAFTER;
820 this.snapVisitCounter = 1; // count visits from 1 (user will write 1, means 1st visit)
821 this.snapNodeCounter = 0; // count nodes from 0
824 state.DISJOINTDVISITSTACK ||
825 state.DISJOINTDVISITPQUE ||
826 state.DISJOINTDVISITSTACKEESONTOP;
827 assert !(state.DISJOINTDVISITSTACK && state.DISJOINTDVISITPQUE);
828 assert !(state.DISJOINTDVISITSTACK && state.DISJOINTDVISITSTACKEESONTOP);
829 assert !(state.DISJOINTDVISITPQUE && state.DISJOINTDVISITSTACKEESONTOP);
831 // set some static configuration for ReachGraphs
832 ReachGraph.allocationDepth = allocationDepth;
833 ReachGraph.typeUtil = typeUtil;
834 ReachGraph.state = state;
836 ReachGraph.initOutOfScopeTemps();
838 ReachGraph.debugCallSiteVisitStartCapture
839 = state.DISJOINTDEBUGCALLVISITTOSTART;
841 ReachGraph.debugCallSiteNumVisitsToCapture
842 = state.DISJOINTDEBUGCALLNUMVISITS;
844 ReachGraph.debugCallSiteStopAfter
845 = state.DISJOINTDEBUGCALLSTOPAFTER;
847 ReachGraph.debugCallSiteVisitCounter
848 = 0; // count visits from 1, is incremented before first visit
850 pm = new PointerMethod();
852 if( state.DO_DEFINITE_REACH_ANALYSIS ) {
853 doDefiniteReachAnalysis = true;
854 definiteReachAnalysis = new DefiniteReachAnalysis( pm );
858 if( suppressOutput ) {
859 System.out.println("* Running disjoint reachability analysis with output suppressed! *");
863 allocateStructures();
865 initImplicitStringsModel();
869 double timeStartAnalysis = (double) System.nanoTime();
871 // start interprocedural fixed-point computation
874 } catch( IOException e ) {
875 throw new Error("IO Exception while writing disjointness analysis output.");
878 analysisComplete=true;
880 double timeEndAnalysis = (double) System.nanoTime();
881 double dt = (timeEndAnalysis - timeStartAnalysis)/(Math.pow(10.0, 9.0) );
884 if( sitesToFlag != null ) {
885 treport = String.format("Disjoint reachability analysis flagged %d sites and took %.3f sec.", sitesToFlag.size(), dt);
886 if(sitesToFlag.size()>0) {
887 treport+="\nFlagged sites:"+"\n"+sitesToFlag.toString();
890 treport = String.format("Disjoint reachability analysis took %.3f sec.", dt);
892 String justtime = String.format("%.2f", dt);
893 System.out.println(treport);
897 if( writeFinalDOTs && !writeAllIncrementalDOTs ) {
901 if( state.DISJOINTWRITEIHMS ) {
905 if( state.DISJOINTWRITEINITCONTEXTS ) {
906 writeInitialContexts();
909 if( state.DISJOINT_WRITE_ALL_NODE_FINAL_GRAPHS ) {
910 writeFinalGraphsForEveryNode();
913 if( state.DISJOINTALIASFILE != null && !suppressOutput ) {
915 writeAllSharing(state.DISJOINTALIASFILE, treport, justtime, state.DISJOINTALIASTAB, state.lines);
917 writeAllSharingJava(state.DISJOINTALIASFILE,
920 state.DISJOINTALIASTAB,
927 buildStateMachines.writeStateMachines();
930 } catch( IOException e ) {
931 throw new Error("IO Exception while writing disjointness analysis output.");
936 protected boolean moreDescriptorsToVisit() {
937 if( state.DISJOINTDVISITSTACK ||
938 state.DISJOINTDVISITSTACKEESONTOP
940 return !descriptorsToVisitStack.isEmpty();
942 } else if( state.DISJOINTDVISITPQUE ) {
943 return !descriptorsToVisitQ.isEmpty();
946 throw new Error("Neither descriptor visiting mode set");
950 // fixed-point computation over the call graph--when a
951 // method's callees are updated, it must be reanalyzed
952 protected void analyzeMethods() throws java.io.IOException {
954 // task or non-task (java) mode determines what the roots
955 // of the call chain are, and establishes the set of methods
956 // reachable from the roots that will be analyzed
959 if( !suppressOutput ) {
960 System.out.println("Bamboo mode...");
963 Iterator taskItr = state.getTaskSymbolTable().getDescriptorsIterator();
964 while( taskItr.hasNext() ) {
965 TaskDescriptor td = (TaskDescriptor) taskItr.next();
966 if( !descriptorsToAnalyze.contains(td) ) {
967 // add all methods transitively reachable from the
969 descriptorsToAnalyze.add(td);
970 descriptorsToAnalyze.addAll(callGraph.getAllMethods(td) );
975 if( !suppressOutput ) {
976 System.out.println("Java mode...");
979 // add all methods transitively reachable from the
980 // source's main to set for analysis
981 mdSourceEntry = typeUtil.getMain();
982 descriptorsToAnalyze.add(mdSourceEntry);
983 descriptorsToAnalyze.addAll(callGraph.getAllMethods(mdSourceEntry) );
985 // fabricate an empty calling context that will call
986 // the source's main, but call graph doesn't know
987 // about it, so explicitly add it
988 makeAnalysisEntryMethod(mdSourceEntry);
989 descriptorsToAnalyze.add(mdAnalysisEntry);
994 // now, depending on the interprocedural mode for visiting
995 // methods, set up the needed data structures
997 if( state.DISJOINTDVISITPQUE ) {
999 // topologically sort according to the call graph so
1000 // leaf calls are last, helps build contexts up first
1001 LinkedList<Descriptor> sortedDescriptors =
1002 topologicalSort(descriptorsToAnalyze);
1004 // add sorted descriptors to priority queue, and duplicate
1005 // the queue as a set for efficiently testing whether some
1006 // method is marked for analysis
1008 Iterator<Descriptor> dItr;
1010 // for the priority queue, give items at the head
1011 // of the sorted list a low number (highest priority)
1012 while( !sortedDescriptors.isEmpty() ) {
1013 Descriptor d = sortedDescriptors.removeFirst();
1014 mapDescriptorToPriority.put(d, new Integer(p) );
1015 descriptorsToVisitQ.add(new DescriptorQWrapper(p, d) );
1016 descriptorsToVisitSet.add(d);
1020 } else if( state.DISJOINTDVISITSTACK ||
1021 state.DISJOINTDVISITSTACKEESONTOP
1023 // if we're doing the stack scheme, just throw the root
1024 // method or tasks on the stack
1026 Iterator taskItr = state.getTaskSymbolTable().getDescriptorsIterator();
1027 while( taskItr.hasNext() ) {
1028 TaskDescriptor td = (TaskDescriptor) taskItr.next();
1029 descriptorsToVisitStack.add(td);
1030 descriptorsToVisitSet.add(td);
1034 descriptorsToVisitStack.add(mdAnalysisEntry);
1035 descriptorsToVisitSet.add(mdAnalysisEntry);
1039 throw new Error("Unknown method scheduling mode");
1043 // analyze scheduled methods until there are no more to visit
1044 while( moreDescriptorsToVisit() ) {
1045 Descriptor d = null;
1047 if( state.DISJOINTDVISITSTACK ||
1048 state.DISJOINTDVISITSTACKEESONTOP
1050 d = descriptorsToVisitStack.pop();
1052 } else if( state.DISJOINTDVISITPQUE ) {
1053 d = descriptorsToVisitQ.poll().getDescriptor();
1056 assert descriptorsToVisitSet.contains(d);
1057 descriptorsToVisitSet.remove(d);
1059 // because the task or method descriptor just extracted
1060 // was in the "to visit" set it either hasn't been analyzed
1061 // yet, or some method that it depends on has been
1062 // updated. Recompute a complete reachability graph for
1063 // this task/method and compare it to any previous result.
1064 // If there is a change detected, add any methods/tasks
1065 // that depend on this one to the "to visit" set.
1067 if( !suppressOutput ) {
1068 System.out.println("Analyzing " + d);
1071 if( state.DISJOINTDVISITSTACKEESONTOP ) {
1072 assert calleesToEnqueue.isEmpty();
1075 ReachGraph rg = analyzeMethod(d);
1076 ReachGraph rgPrev = getPartial(d);
1078 if( !rg.equals(rgPrev) ) {
1081 if( state.DISJOINTDEBUGSCHEDULING ) {
1082 System.out.println(" complete graph changed, scheduling callers for analysis:");
1085 // results for d changed, so enqueue dependents
1086 // of d for further analysis
1087 Iterator<Descriptor> depsItr = getDependents(d).iterator();
1088 while( depsItr.hasNext() ) {
1089 Descriptor dNext = depsItr.next();
1092 if( state.DISJOINTDEBUGSCHEDULING ) {
1093 System.out.println(" "+dNext);
1098 // whether or not the method under analysis changed,
1099 // we may have some callees that are scheduled for
1100 // more analysis, and they should go on the top of
1101 // the stack now (in other method-visiting modes they
1102 // are already enqueued at this point
1103 if( state.DISJOINTDVISITSTACKEESONTOP ) {
1104 Iterator<Descriptor> depsItr = calleesToEnqueue.iterator();
1105 while( depsItr.hasNext() ) {
1106 Descriptor dNext = depsItr.next();
1109 calleesToEnqueue.clear();
1115 protected ReachGraph analyzeMethod(Descriptor d)
1116 throws java.io.IOException {
1118 // get the flat code for this descriptor
1120 if( d == mdAnalysisEntry ) {
1121 fm = fmAnalysisEntry;
1123 fm = state.getMethodFlat(d);
1125 pm.analyzeMethod(fm);
1127 // intraprocedural work set
1128 Set<FlatNode> flatNodesToVisit = new HashSet<FlatNode>();
1129 flatNodesToVisit.add(fm);
1131 // if determinism is desired by client, shadow the
1132 // set with a queue to make visit order deterministic
1133 Queue<FlatNode> flatNodesToVisitQ = null;
1134 if( determinismDesired ) {
1135 flatNodesToVisitQ = new LinkedList<FlatNode>();
1136 flatNodesToVisitQ.add(fm);
1139 // start a new mapping of partial results
1140 mapFlatNodeToReachGraph =
1141 new Hashtable<FlatNode, ReachGraph>();
1143 // the set of return nodes partial results that will be combined as
1144 // the final, conservative approximation of the entire method
1145 HashSet<FlatReturnNode> setReturns = new HashSet<FlatReturnNode>();
1149 boolean snapThisMethod = false;
1150 if( takeDebugSnapshots && d instanceof MethodDescriptor ) {
1151 MethodDescriptor mdThisMethod = (MethodDescriptor)d;
1152 ClassDescriptor cdThisMethod = mdThisMethod.getClassDesc();
1153 if( cdThisMethod != null ) {
1155 descSymbolDebug.equals( cdThisMethod.getSymbol()+
1157 mdThisMethod.getSymbol()
1164 while( !flatNodesToVisit.isEmpty() ) {
1167 if( determinismDesired ) {
1168 assert !flatNodesToVisitQ.isEmpty();
1169 fn = flatNodesToVisitQ.remove();
1171 fn = flatNodesToVisit.iterator().next();
1173 flatNodesToVisit.remove(fn);
1175 // effect transfer function defined by this node,
1176 // then compare it to the old graph at this node
1177 // to see if anything was updated.
1179 ReachGraph rg = new ReachGraph();
1180 TaskDescriptor taskDesc;
1181 if(fn instanceof FlatMethod && (taskDesc=((FlatMethod)fn).getTask())!=null) {
1182 if(mapDescriptorToReachGraph.containsKey(taskDesc)) {
1183 // retrieve existing reach graph if it is not first time
1184 rg=mapDescriptorToReachGraph.get(taskDesc);
1186 // create initial reach graph for a task
1187 rg=createInitialTaskReachGraph((FlatMethod)fn);
1189 mapDescriptorToReachGraph.put(taskDesc, rg);
1193 // start by merging all node's parents' graphs
1194 for( int i = 0; i < pm.numPrev(fn); ++i ) {
1195 FlatNode pn = pm.getPrev(fn,i);
1196 if( mapFlatNodeToReachGraph.containsKey(pn) ) {
1197 ReachGraph rgParent = mapFlatNodeToReachGraph.get(pn);
1203 if( snapThisMethod ) {
1204 debugSnapshot(rg, fn, true);
1208 // modify rg with appropriate transfer function
1209 rg = analyzeFlatNode(d, fm, fn, setReturns, rg);
1212 if( snapThisMethod ) {
1213 debugSnapshot(rg, fn, false);
1218 // if the results of the new graph are different from
1219 // the current graph at this node, replace the graph
1220 // with the update and enqueue the children
1221 ReachGraph rgPrev = mapFlatNodeToReachGraph.get(fn);
1222 if( !rg.equals(rgPrev) ) {
1223 mapFlatNodeToReachGraph.put(fn, rg);
1225 // we don't necessarily want to keep the reach graph for every
1226 // node in the program unless a client or the user wants it
1227 if( state.DISJOINT_WRITE_ALL_NODE_FINAL_GRAPHS ) {
1228 mapFlatNodeToReachGraphPersist.put(fn, rg);
1231 for( int i = 0; i < pm.numNext(fn); i++ ) {
1232 FlatNode nn = pm.getNext(fn, i);
1234 flatNodesToVisit.add(nn);
1235 if( determinismDesired ) {
1236 flatNodesToVisitQ.add(nn);
1243 // end by merging all return nodes into a complete
1244 // reach graph that represents all possible heap
1245 // states after the flat method returns
1246 ReachGraph completeGraph = new ReachGraph();
1248 if( setReturns.isEmpty() ) {
1249 System.out.println( "d = "+d );
1252 assert !setReturns.isEmpty();
1253 Iterator retItr = setReturns.iterator();
1254 while( retItr.hasNext() ) {
1255 FlatReturnNode frn = (FlatReturnNode) retItr.next();
1257 assert mapFlatNodeToReachGraph.containsKey(frn);
1258 ReachGraph rgRet = mapFlatNodeToReachGraph.get(frn);
1260 completeGraph.merge(rgRet);
1264 if( snapThisMethod ) {
1265 // increment that we've visited the debug snap
1266 // method, and reset the node counter
1267 System.out.println(" @@@ debug snap at visit "+snapVisitCounter);
1269 snapNodeCounter = 0;
1271 if( snapVisitCounter == visitStartCapture + numVisitsToCapture &&
1274 System.out.println("!!! Stopping analysis after debug snap captures. !!!");
1280 return completeGraph;
1284 protected ReachGraph
1285 analyzeFlatNode(Descriptor d,
1286 FlatMethod fmContaining,
1288 HashSet<FlatReturnNode> setRetNodes,
1290 ) throws java.io.IOException {
1293 // any variables that are no longer live should be
1294 // nullified in the graph to reduce edges
1295 //rg.nullifyDeadVars( liveness.getLiveInTemps( fmContaining, fn ) );
1299 FieldDescriptor fld;
1300 TypeDescriptor tdElement;
1301 FieldDescriptor fdElement;
1302 FlatSESEEnterNode sese;
1303 FlatSESEExitNode fsexn;
1305 boolean alreadyReachable;
1306 Set<EdgeKey> edgeKeysForLoad;
1307 Set<EdgeKey> edgeKeysRemoved;
1308 Set<EdgeKey> edgeKeysAdded;
1309 Set<DefiniteReachState.FdEntry> edgesToElideFromProp;
1311 //Stores the flatnode's reach graph at enter
1312 ReachGraph rgOnEnter = new ReachGraph();
1313 rgOnEnter.merge(rg);
1314 fn2rgAtEnter.put(fn, rgOnEnter);
1318 boolean didDefReachTransfer = false;
1322 // use node type to decide what transfer function
1323 // to apply to the reachability graph
1324 switch( fn.kind() ) {
1326 case FKind.FlatGenReachNode: {
1327 FlatGenReachNode fgrn = (FlatGenReachNode) fn;
1329 System.out.println(" Generating reach graph for program point: "+fgrn.getGraphName() );
1332 rg.writeGraph("genReach"+fgrn.getGraphName(),
1333 true, // write labels (variables)
1334 true, // selectively hide intermediate temp vars
1335 true, // prune unreachable heap regions
1336 false, // hide reachability altogether
1337 true, // hide subset reachability states
1338 true, // hide predicates
1339 true); //false); // hide edge taints
1343 case FKind.FlatGenDefReachNode: {
1344 FlatGenDefReachNode fgdrn = (FlatGenDefReachNode) fn;
1345 if( doDefiniteReachAnalysis ) {
1346 definiteReachAnalysis.writeState( fn, fgdrn.getOutputName() );
1351 case FKind.FlatMethod: {
1352 // construct this method's initial heap model (IHM)
1353 // since we're working on the FlatMethod, we know
1354 // the incoming ReachGraph 'rg' is empty
1356 Hashtable<FlatCall, ReachGraph> heapsFromCallers =
1357 getIHMcontributions(d);
1359 Set entrySet = heapsFromCallers.entrySet();
1360 Iterator itr = entrySet.iterator();
1361 while( itr.hasNext() ) {
1362 Map.Entry me = (Map.Entry)itr.next();
1363 FlatCall fc = (FlatCall) me.getKey();
1364 ReachGraph rgContrib = (ReachGraph) me.getValue();
1366 // note that "fc.getMethod()" like (Object.toString)
1367 // might not be equal to "d" like (String.toString)
1368 // because the mapping gets set up when we resolve
1370 rg.merge(rgContrib);
1373 // additionally, we are enforcing STRICT MONOTONICITY for the
1374 // method's initial context, so grow the context by whatever
1375 // the previously computed context was, and put the most
1376 // up-to-date context back in the map
1377 ReachGraph rgPrevContext = mapDescriptorToInitialContext.get(d);
1378 rg.merge(rgPrevContext);
1379 mapDescriptorToInitialContext.put(d, rg);
1381 if( doDefiniteReachAnalysis ) {
1382 FlatMethod fm = (FlatMethod) fn;
1383 Set<TempDescriptor> params = new HashSet<TempDescriptor>();
1384 for( int i = 0; i < fm.numParameters(); ++i ) {
1385 params.add( fm.getParameter( i ) );
1387 definiteReachAnalysis.methodEntry( fn, params );
1388 didDefReachTransfer = true;
1392 case FKind.FlatOpNode:
1393 FlatOpNode fon = (FlatOpNode) fn;
1394 if( fon.getOp().getOp() == Operation.ASSIGN ) {
1395 lhs = fon.getDest();
1396 rhs = fon.getLeft();
1398 // before transfer, do effects analysis support
1399 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1400 if(rblockRel.isPotentialStallSite(fn)) {
1401 // x gets status of y
1402 if(!accessible.isAccessible(fn, rhs)) {
1403 rg.makeInaccessible(lhs);
1409 rg.assignTempXEqualToTempY(lhs, rhs);
1411 if( doDefiniteReachAnalysis ) {
1412 definiteReachAnalysis.copy( fn, lhs, rhs );
1413 didDefReachTransfer = true;
1418 case FKind.FlatCastNode:
1419 FlatCastNode fcn = (FlatCastNode) fn;
1423 TypeDescriptor td = fcn.getType();
1426 // before transfer, do effects analysis support
1427 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1428 if(rblockRel.isPotentialStallSite(fn)) {
1429 // x gets status of y
1430 if(!accessible.isAccessible(fn,rhs)) {
1431 rg.makeInaccessible(lhs);
1437 rg.assignTempXEqualToCastedTempY(lhs, rhs, td);
1439 if( doDefiniteReachAnalysis ) {
1440 definiteReachAnalysis.copy( fn, lhs, rhs );
1441 didDefReachTransfer = true;
1445 case FKind.FlatFieldNode:
1446 FlatFieldNode ffn = (FlatFieldNode) fn;
1450 fld = ffn.getField();
1452 // before graph transform, possible inject
1453 // a stall-site taint
1454 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1456 if(rblockRel.isPotentialStallSite(fn)) {
1457 // x=y.f, stall y if not accessible
1458 // contributes read effects on stall site of y
1459 if(!accessible.isAccessible(fn,rhs)) {
1460 rg.taintStallSite(fn, rhs);
1463 // after this, x and y are accessbile.
1464 rg.makeAccessible(lhs);
1465 rg.makeAccessible(rhs);
1469 edgeKeysForLoad = null;
1470 if( doDefiniteReachAnalysis ) {
1471 edgeKeysForLoad = new HashSet<EdgeKey>();
1474 if( shouldAnalysisTrack(fld.getType() ) ) {
1476 rg.assignTempXEqualToTempYFieldF( lhs, rhs, fld, fn, edgeKeysForLoad );
1478 if( doDefiniteReachAnalysis ) {
1479 definiteReachAnalysis.load( fn, lhs, rhs, fld, edgeKeysForLoad );
1480 didDefReachTransfer = true;
1484 // after transfer, use updated graph to
1485 // do effects analysis
1486 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1487 effectsAnalysis.analyzeFlatFieldNode(rg, rhs, fld, fn);
1491 case FKind.FlatSetFieldNode:
1492 FlatSetFieldNode fsfn = (FlatSetFieldNode) fn;
1494 lhs = fsfn.getDst();
1495 fld = fsfn.getField();
1496 rhs = fsfn.getSrc();
1498 boolean strongUpdate = false;
1500 alreadyReachable = false;
1501 edgeKeysRemoved = null;
1502 edgeKeysAdded = null;
1503 edgesToElideFromProp = null;
1504 if( doDefiniteReachAnalysis ) {
1505 alreadyReachable = definiteReachAnalysis.isAlreadyReachable( rhs, lhs, fn );
1506 edgeKeysRemoved = new HashSet<EdgeKey>();
1507 edgeKeysAdded = new HashSet<EdgeKey>();
1508 edgesToElideFromProp = definiteReachAnalysis.edgesToElidePropagation( lhs, rhs, fn );
1511 // before transfer func, possibly inject
1512 // stall-site taints
1513 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1515 if(rblockRel.isPotentialStallSite(fn)) {
1516 // x.y=f , stall x and y if they are not accessible
1517 // also contribute write effects on stall site of x
1518 if(!accessible.isAccessible(fn,lhs)) {
1519 rg.taintStallSite(fn, lhs);
1522 if(!accessible.isAccessible(fn,rhs)) {
1523 rg.taintStallSite(fn, rhs);
1526 // accessible status update
1527 rg.makeAccessible(lhs);
1528 rg.makeAccessible(rhs);
1532 if( shouldAnalysisTrack(fld.getType() ) ) {
1534 strongUpdate = rg.assignTempXFieldFEqualToTempY( lhs,
1541 edgesToElideFromProp );
1542 if( doDefiniteReachAnalysis ) {
1543 definiteReachAnalysis.store( fn,
1549 didDefReachTransfer = true;
1553 // use transformed graph to do effects analysis
1554 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1555 effectsAnalysis.analyzeFlatSetFieldNode(rg, lhs, fld, fn, strongUpdate);
1559 case FKind.FlatElementNode:
1560 FlatElementNode fen = (FlatElementNode) fn;
1565 assert rhs.getType() != null;
1566 assert rhs.getType().isArray();
1568 tdElement = rhs.getType().dereference();
1569 fdElement = getArrayField(tdElement);
1571 // before transfer func, possibly inject
1573 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1574 if(rblockRel.isPotentialStallSite(fn)) {
1575 // x=y.f, stall y if not accessible
1576 // contributes read effects on stall site of y
1577 // after this, x and y are accessbile.
1578 if(!accessible.isAccessible(fn,rhs)) {
1579 rg.taintStallSite(fn, rhs);
1582 rg.makeAccessible(lhs);
1583 rg.makeAccessible(rhs);
1587 edgeKeysForLoad = null;
1588 if( doDefiniteReachAnalysis ) {
1589 edgeKeysForLoad = new HashSet<EdgeKey>();
1592 if( shouldAnalysisTrack(lhs.getType() ) ) {
1594 rg.assignTempXEqualToTempYFieldF( lhs, rhs, fdElement, fn, edgeKeysForLoad );
1596 if( doDefiniteReachAnalysis ) {
1597 definiteReachAnalysis.load( fn, lhs, rhs, fdElement, edgeKeysForLoad );
1598 didDefReachTransfer = true;
1602 // use transformed graph to do effects analysis
1603 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1604 effectsAnalysis.analyzeFlatFieldNode(rg, rhs, fdElement, fn);
1608 case FKind.FlatSetElementNode:
1609 FlatSetElementNode fsen = (FlatSetElementNode) fn;
1611 lhs = fsen.getDst();
1612 rhs = fsen.getSrc();
1614 assert lhs.getType() != null;
1615 assert lhs.getType().isArray();
1617 tdElement = lhs.getType().dereference();
1618 fdElement = getArrayField(tdElement);
1620 alreadyReachable = false;
1621 edgeKeysRemoved = null;
1622 edgeKeysAdded = null;
1623 edgesToElideFromProp = null;
1624 if( doDefiniteReachAnalysis ) {
1625 alreadyReachable = definiteReachAnalysis.isAlreadyReachable( rhs, lhs, fn );
1626 edgeKeysRemoved = new HashSet<EdgeKey>();
1627 edgeKeysAdded = new HashSet<EdgeKey>();
1628 edgesToElideFromProp = definiteReachAnalysis.edgesToElidePropagation( lhs, rhs, fn );
1631 // before transfer func, possibly inject
1632 // stall-site taints
1633 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1635 if(rblockRel.isPotentialStallSite(fn)) {
1636 // x.y=f , stall x and y if they are not accessible
1637 // also contribute write effects on stall site of x
1638 if(!accessible.isAccessible(fn,lhs)) {
1639 rg.taintStallSite(fn, lhs);
1642 if(!accessible.isAccessible(fn,rhs)) {
1643 rg.taintStallSite(fn, rhs);
1646 // accessible status update
1647 rg.makeAccessible(lhs);
1648 rg.makeAccessible(rhs);
1652 if( shouldAnalysisTrack(rhs.getType() ) ) {
1653 // transfer func, BUT
1654 // skip this node if it cannot create new reachability paths
1655 if( !arrayReferencees.doesNotCreateNewReaching(fsen) ) {
1656 rg.assignTempXFieldFEqualToTempY( lhs,
1663 edgesToElideFromProp );
1666 if( doDefiniteReachAnalysis ) {
1667 definiteReachAnalysis.store( fn,
1673 didDefReachTransfer = true;
1677 // use transformed graph to do effects analysis
1678 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1679 effectsAnalysis.analyzeFlatSetFieldNode(rg, lhs, fdElement, fn,
1685 FlatNew fnn = (FlatNew) fn;
1687 if( shouldAnalysisTrack(lhs.getType() ) ) {
1688 AllocSite as = getAllocSiteFromFlatNewPRIVATE(fnn);
1690 // before transform, support effects analysis
1691 if (doEffectsAnalysis && fmContaining != fmAnalysisEntry) {
1692 if (rblockRel.isPotentialStallSite(fn)) {
1693 // after creating new object, lhs is accessible
1694 rg.makeAccessible(lhs);
1699 rg.assignTempEqualToNewAlloc(lhs, as);
1701 if( doDefiniteReachAnalysis ) {
1702 definiteReachAnalysis.newObject( fn, lhs );
1703 didDefReachTransfer = true;
1709 case FKind.FlatLiteralNode:
1710 // BIG NOTE: this transfer function is only here for
1711 // points-to information for String literals. That's it.
1712 // Effects and disjoint reachability and all of that don't
1713 // care about references to literals.
1714 FlatLiteralNode fln = (FlatLiteralNode) fn;
1716 if( fln.getType().equals( stringType ) ) {
1717 rg.assignTempEqualToStringLiteral( fln.getDst(),
1718 newStringLiteralAlloc,
1719 newStringLiteralBytesAlloc,
1725 case FKind.FlatSESEEnterNode:
1726 sese = (FlatSESEEnterNode) fn;
1728 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1730 // always remove ALL stall site taints at enter
1731 rg.removeAllStallSiteTaints();
1733 // inject taints for in-set vars
1734 rg.taintInSetVars(sese);
1739 case FKind.FlatSESEExitNode:
1740 fsexn = (FlatSESEExitNode) fn;
1741 sese = fsexn.getFlatEnter();
1743 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1745 // @ sese exit make all live variables
1746 // inaccessible to later parent statements
1747 rg.makeInaccessible(liveness.getLiveInTemps(fmContaining, fn) );
1749 // always remove ALL stall site taints at exit
1750 rg.removeAllStallSiteTaints();
1752 // remove in-set var taints for the exiting rblock
1753 rg.removeInContextTaints(sese);
1758 case FKind.FlatCall: {
1759 Descriptor mdCaller;
1760 if( fmContaining.getMethod() != null ) {
1761 mdCaller = fmContaining.getMethod();
1763 mdCaller = fmContaining.getTask();
1765 FlatCall fc = (FlatCall) fn;
1766 MethodDescriptor mdCallee = fc.getMethod();
1767 FlatMethod fmCallee = state.getMethodFlat(mdCallee);
1770 if( doDefiniteReachAnalysis ) {
1771 definiteReachAnalysis.methodCall( fn, fc.getReturnTemp() );
1772 didDefReachTransfer = true;
1776 // the transformation for a call site should update the
1777 // current heap abstraction with any effects from the callee,
1778 // or if the method is virtual, the effects from any possible
1779 // callees, so find the set of callees...
1780 Set<MethodDescriptor> setPossibleCallees;
1781 if( determinismDesired ) {
1782 // use an ordered set
1783 setPossibleCallees = new TreeSet<MethodDescriptor>(dComp);
1785 // otherwise use a speedy hashset
1786 setPossibleCallees = new HashSet<MethodDescriptor>();
1789 if( mdCallee.isStatic() ) {
1790 setPossibleCallees.add(mdCallee);
1792 TypeDescriptor typeDesc = fc.getThis().getType();
1793 setPossibleCallees.addAll(callGraph.getMethods(mdCallee,
1799 DebugCallSiteData dcsd = new DebugCallSiteData();
1801 ReachGraph rgMergeOfPossibleCallers = new ReachGraph();
1804 Iterator<MethodDescriptor> mdItr = setPossibleCallees.iterator();
1805 while( mdItr.hasNext() ) {
1806 MethodDescriptor mdPossible = mdItr.next();
1807 FlatMethod fmPossible = state.getMethodFlat(mdPossible);
1809 addDependent(mdPossible, // callee
1813 // decide for each possible resolution of the method whether we
1814 // want to debug this call site
1815 decideDebugCallSite( dcsd, mdCaller, mdPossible );
1819 // calculate the heap this call site can reach--note this is
1820 // not used for the current call site transform, we are
1821 // grabbing this heap model for future analysis of the callees,
1822 // so if different results emerge we will return to this site
1823 ReachGraph heapForThisCall_old =
1824 getIHMcontribution(mdPossible, fc);
1826 // the computation of the callee-reachable heap
1827 // is useful for making the callee starting point
1828 // and for applying the call site transfer function
1829 Set<Integer> callerNodeIDsCopiedToCallee =
1830 new HashSet<Integer>();
1833 ReachGraph heapForThisCall_cur =
1834 rg.makeCalleeView(fc,
1836 callerNodeIDsCopiedToCallee,
1841 // enforce that a call site contribution can only
1842 // monotonically increase
1843 heapForThisCall_cur.merge(heapForThisCall_old);
1845 if( !heapForThisCall_cur.equals(heapForThisCall_old) ) {
1846 // if heap at call site changed, update the contribution,
1847 // and reschedule the callee for analysis
1848 addIHMcontribution(mdPossible, fc, heapForThisCall_cur);
1850 // map a FlatCall to its enclosing method/task descriptor
1851 // so we can write that info out later
1852 fc2enclosing.put(fc, mdCaller);
1854 if( state.DISJOINTDEBUGSCHEDULING ) {
1855 System.out.println(" context changed at callsite: "+fc+", scheduling callee: "+mdPossible);
1858 if( state.DISJOINTDVISITSTACKEESONTOP ) {
1859 calleesToEnqueue.add(mdPossible);
1861 enqueue(mdPossible);
1868 // don't alter the working graph (rg) until we compute a
1869 // result for every possible callee, merge them all together,
1870 // then set rg to that
1871 ReachGraph rgPossibleCaller = new ReachGraph();
1872 rgPossibleCaller.merge(rg);
1874 ReachGraph rgPossibleCallee = getPartial(mdPossible);
1876 if( rgPossibleCallee == null ) {
1877 // if this method has never been analyzed just schedule it
1878 // for analysis and skip over this call site for now
1879 if( state.DISJOINTDVISITSTACKEESONTOP ) {
1880 calleesToEnqueue.add(mdPossible);
1882 enqueue(mdPossible);
1885 if( state.DISJOINTDEBUGSCHEDULING ) {
1886 System.out.println(" callee hasn't been analyzed, scheduling: "+mdPossible);
1892 // calculate the method call transform
1893 rgPossibleCaller.resolveMethodCall(fc,
1896 callerNodeIDsCopiedToCallee,
1901 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1902 if( !accessible.isAccessible(fn, ReachGraph.tdReturn) ) {
1903 rgPossibleCaller.makeInaccessible(fc.getReturnTemp() );
1909 rgMergeOfPossibleCallers.merge(rgPossibleCaller);
1914 statusDebugCallSite( dcsd );
1918 // now that we've taken care of building heap models for
1919 // callee analysis, finish this transformation
1920 rg = rgMergeOfPossibleCallers;
1923 // jjenista: what is this? It breaks compilation
1924 // of programs with no tasks/SESEs/rblocks...
1925 //XXXXXXXXXXXXXXXXXXXXXXXXX
1926 //need to consider more
1927 if( state.OOOJAVA ) {
1928 FlatNode nextFN=fmCallee.getNext(0);
1929 if( nextFN instanceof FlatSESEEnterNode ) {
1930 FlatSESEEnterNode calleeSESE=(FlatSESEEnterNode)nextFN;
1931 if(!calleeSESE.getIsLeafSESE()) {
1932 rg.makeInaccessible(liveness.getLiveInTemps(fmContaining, fn) );
1940 case FKind.FlatReturnNode:
1941 FlatReturnNode frn = (FlatReturnNode) fn;
1942 rhs = frn.getReturnTemp();
1944 // before transfer, do effects analysis support
1945 if( doEffectsAnalysis && fmContaining != fmAnalysisEntry ) {
1946 if(!accessible.isAccessible(fn,rhs)) {
1947 rg.makeInaccessible(ReachGraph.tdReturn);
1951 if( rhs != null && shouldAnalysisTrack(rhs.getType() ) ) {
1952 rg.assignReturnEqualToTemp(rhs);
1955 setRetNodes.add(frn);
1962 if( doDefiniteReachAnalysis && !didDefReachTransfer ) {
1963 definiteReachAnalysis.otherStatement( fn );
1968 // dead variables were removed before the above transfer function
1969 // was applied, so eliminate heap regions and edges that are no
1970 // longer part of the abstractly-live heap graph, and sweep up
1971 // and reachability effects that are altered by the reduction
1972 //rg.abstractGarbageCollect();
1976 // back edges are strictly monotonic
1977 if( pm.isBackEdge(fn) ) {
1978 ReachGraph rgPrevResult = mapBackEdgeToMonotone.get(fn);
1979 rg.merge(rgPrevResult);
1980 mapBackEdgeToMonotone.put(fn, rg);
1984 ReachGraph rgOnExit = new ReachGraph();
1986 fn2rgAtExit.put(fn, rgOnExit);
1990 // at this point rg should be the correct update
1991 // by an above transfer function, or untouched if
1992 // the flat node type doesn't affect the heap
1998 // this method should generate integers strictly greater than zero!
1999 // special "shadow" regions are made from a heap region by negating
2001 static public Integer generateUniqueHeapRegionNodeID() {
2003 return new Integer(uniqueIDcount);
2008 static public FieldDescriptor getArrayField(TypeDescriptor tdElement) {
2009 FieldDescriptor fdElement = mapTypeToArrayField.get(tdElement);
2010 if( fdElement == null ) {
2011 fdElement = new FieldDescriptor(new Modifiers(Modifiers.PUBLIC),
2013 arrayElementFieldName,
2016 mapTypeToArrayField.put(tdElement, fdElement);
2023 private void writeFinalGraphs() {
2024 Set entrySet = mapDescriptorToCompleteReachGraph.entrySet();
2025 Iterator itr = entrySet.iterator();
2026 while( itr.hasNext() ) {
2027 Map.Entry me = (Map.Entry)itr.next();
2028 Descriptor d = (Descriptor) me.getKey();
2029 ReachGraph rg = (ReachGraph) me.getValue();
2032 if( d instanceof TaskDescriptor ) {
2033 graphName = "COMPLETEtask"+d;
2035 graphName = "COMPLETE"+d;
2038 rg.writeGraph(graphName,
2039 true, // write labels (variables)
2040 true, // selectively hide intermediate temp vars
2041 true, // prune unreachable heap regions
2042 false, // hide reachability altogether
2043 true, // hide subset reachability states
2044 true, // hide predicates
2045 true); // hide edge taints
2049 private void writeFinalIHMs() {
2050 Iterator d2IHMsItr = mapDescriptorToIHMcontributions.entrySet().iterator();
2051 while( d2IHMsItr.hasNext() ) {
2052 Map.Entry me1 = (Map.Entry)d2IHMsItr.next();
2053 Descriptor d = (Descriptor) me1.getKey();
2054 Hashtable<FlatCall, ReachGraph> IHMs = (Hashtable<FlatCall, ReachGraph>)me1.getValue();
2056 Iterator fc2rgItr = IHMs.entrySet().iterator();
2057 while( fc2rgItr.hasNext() ) {
2058 Map.Entry me2 = (Map.Entry)fc2rgItr.next();
2059 FlatCall fc = (FlatCall) me2.getKey();
2060 ReachGraph rg = (ReachGraph) me2.getValue();
2062 rg.writeGraph("IHMPARTFOR"+d+"FROM"+fc2enclosing.get(fc)+fc,
2063 true, // write labels (variables)
2064 true, // selectively hide intermediate temp vars
2065 true, // hide reachability altogether
2066 true, // prune unreachable heap regions
2067 true, // hide subset reachability states
2068 false, // hide predicates
2069 true); // hide edge taints
2074 private void writeInitialContexts() {
2075 Set entrySet = mapDescriptorToInitialContext.entrySet();
2076 Iterator itr = entrySet.iterator();
2077 while( itr.hasNext() ) {
2078 Map.Entry me = (Map.Entry)itr.next();
2079 Descriptor d = (Descriptor) me.getKey();
2080 ReachGraph rg = (ReachGraph) me.getValue();
2082 rg.writeGraph("INITIAL"+d,
2083 true, // write labels (variables)
2084 true, // selectively hide intermediate temp vars
2085 true, // prune unreachable heap regions
2086 false, // hide all reachability
2087 true, // hide subset reachability states
2088 true, // hide predicates
2089 false); // hide edge taints
2093 private void writeFinalGraphsForEveryNode() {
2094 Set entrySet = mapFlatNodeToReachGraphPersist.entrySet();
2095 Iterator itr = entrySet.iterator();
2096 while( itr.hasNext() ) {
2097 Map.Entry me = (Map.Entry) itr.next();
2098 FlatNode fn = (FlatNode) me.getKey();
2099 ReachGraph rg = (ReachGraph) me.getValue();
2101 rg.writeGraph("NODEFINAL"+fn,
2102 true, // write labels (variables)
2103 false, // selectively hide intermediate temp vars
2104 true, // prune unreachable heap regions
2105 true, // hide all reachability
2106 true, // hide subset reachability states
2107 true, // hide predicates
2108 true); // hide edge taints
2113 protected ReachGraph getPartial(Descriptor d) {
2114 return mapDescriptorToCompleteReachGraph.get(d);
2117 protected void setPartial(Descriptor d, ReachGraph rg) {
2118 mapDescriptorToCompleteReachGraph.put(d, rg);
2120 // when the flag for writing out every partial
2121 // result is set, we should spit out the graph,
2122 // but in order to give it a unique name we need
2123 // to track how many partial results for this
2124 // descriptor we've already written out
2125 if( writeAllIncrementalDOTs ) {
2126 if( !mapDescriptorToNumUpdates.containsKey(d) ) {
2127 mapDescriptorToNumUpdates.put(d, new Integer(0) );
2129 Integer n = mapDescriptorToNumUpdates.get(d);
2132 if( d instanceof TaskDescriptor ) {
2133 graphName = d+"COMPLETEtask"+String.format("%05d", n);
2135 graphName = d+"COMPLETE"+String.format("%05d", n);
2138 rg.writeGraph(graphName,
2139 true, // write labels (variables)
2140 true, // selectively hide intermediate temp vars
2141 true, // prune unreachable heap regions
2142 false, // hide all reachability
2143 true, // hide subset reachability states
2144 false, // hide predicates
2145 false); // hide edge taints
2147 mapDescriptorToNumUpdates.put(d, n + 1);
2153 // return just the allocation site associated with one FlatNew node
2154 protected AllocSite getAllocSiteFromFlatNewPRIVATE(FlatNew fnew) {
2156 boolean flagProgrammatically = false;
2157 if( sitesToFlag != null && sitesToFlag.contains(fnew) ) {
2158 flagProgrammatically = true;
2161 if( !mapFlatNewToAllocSite.containsKey(fnew) ) {
2162 AllocSite as = AllocSite.factory(allocationDepth,
2164 fnew.getDisjointId(),
2165 flagProgrammatically
2168 // the newest nodes are single objects
2169 for( int i = 0; i < allocationDepth; ++i ) {
2170 Integer id = generateUniqueHeapRegionNodeID();
2171 as.setIthOldest(i, id);
2172 mapHrnIdToAllocSite.put(id, as);
2175 // the oldest node is a summary node
2176 as.setSummary(generateUniqueHeapRegionNodeID() );
2178 mapFlatNewToAllocSite.put(fnew, as);
2181 return mapFlatNewToAllocSite.get(fnew);
2185 public static boolean shouldAnalysisTrack(TypeDescriptor type) {
2186 // don't track primitive types, but an array
2187 // of primitives is heap memory
2188 if( type.isImmutable() ) {
2189 return type.isArray();
2192 // everything else is an object
2196 protected int numMethodsAnalyzed() {
2197 return descriptorsToAnalyze.size();
2203 // Take in source entry which is the program's compiled entry and
2204 // create a new analysis entry, a method that takes no parameters
2205 // and appears to allocate the command line arguments and call the
2206 // source entry with them. The purpose of this analysis entry is
2207 // to provide a top-level method context with no parameters left.
2208 protected void makeAnalysisEntryMethod(MethodDescriptor mdSourceEntry) {
2210 Modifiers mods = new Modifiers();
2211 mods.addModifier(Modifiers.PUBLIC);
2212 mods.addModifier(Modifiers.STATIC);
2214 TypeDescriptor returnType = new TypeDescriptor(TypeDescriptor.VOID);
2216 this.mdAnalysisEntry =
2217 new MethodDescriptor(mods,
2219 "analysisEntryMethod"
2222 TypeDescriptor argsType = mdSourceEntry.getParamType(0);
2223 TempDescriptor cmdLineArgs =
2224 new TempDescriptor("analysisEntryTemp_args",
2228 new FlatNew(argsType,
2232 this.constructedCmdLineArgsNew = fnArgs;
2234 TypeDescriptor argType = argsType.dereference();
2235 TempDescriptor anArg =
2236 new TempDescriptor("analysisEntryTemp_arg",
2240 new FlatNew(argType,
2244 this.constructedCmdLineArgNew = fnArg;
2246 TypeDescriptor typeIndex = new TypeDescriptor(TypeDescriptor.INT);
2247 TempDescriptor index =
2248 new TempDescriptor("analysisEntryTemp_index",
2251 FlatLiteralNode fli =
2252 new FlatLiteralNode(typeIndex,
2257 FlatSetElementNode fse =
2258 new FlatSetElementNode(cmdLineArgs,
2263 TypeDescriptor typeSize = new TypeDescriptor(TypeDescriptor.INT);
2264 TempDescriptor sizeBytes =
2265 new TempDescriptor("analysisEntryTemp_size",
2268 FlatLiteralNode fls =
2269 new FlatLiteralNode(typeSize,
2274 TempDescriptor strBytes =
2275 new TempDescriptor("analysisEntryTemp_strBytes",
2279 new FlatNew(stringBytesType,
2284 this.constructedCmdLineArgBytesNew = fnBytes;
2286 FlatSetFieldNode fsf =
2287 new FlatSetFieldNode(anArg,
2292 // throw this in so you can always see what the initial heap context
2293 // looks like if you want to, its cheap
2294 FlatGenReachNode fgen = new FlatGenReachNode( "argContext" );
2296 TempDescriptor[] sourceEntryArgs = new TempDescriptor[1];
2297 sourceEntryArgs[0] = cmdLineArgs;
2299 new FlatCall(mdSourceEntry,
2305 FlatReturnNode frn = new FlatReturnNode(null);
2307 FlatExit fe = new FlatExit();
2309 this.fmAnalysisEntry =
2310 new FlatMethod(mdAnalysisEntry,
2314 List<FlatNode> nodes = new LinkedList<FlatNode>();
2315 nodes.add( fnArgs );
2320 nodes.add( fnBytes );
2327 FlatNode current = this.fmAnalysisEntry;
2328 for( FlatNode next: nodes ) {
2329 current.addNext( next );
2334 // jjenista - this is useful for looking at the FlatIRGraph of the
2335 // analysis entry method constructed above if you have to modify it.
2336 // The usual method of writing FlatIRGraphs out doesn't work because
2337 // this flat method is private to the model of this analysis only.
2339 // FlatIRGraph flatMethodWriter =
2340 // new FlatIRGraph( state, false, false, false );
2341 // flatMethodWriter.writeFlatIRGraph( fmAnalysisEntry, "analysisEntry" );
2342 //} catch( IOException e ) {}
2346 protected LinkedList<Descriptor> topologicalSort(Set<Descriptor> toSort) {
2348 Set<Descriptor> discovered;
2350 if( determinismDesired ) {
2351 // use an ordered set
2352 discovered = new TreeSet<Descriptor>(dComp);
2354 // otherwise use a speedy hashset
2355 discovered = new HashSet<Descriptor>();
2358 LinkedList<Descriptor> sorted = new LinkedList<Descriptor>();
2360 Iterator<Descriptor> itr = toSort.iterator();
2361 while( itr.hasNext() ) {
2362 Descriptor d = itr.next();
2364 if( !discovered.contains(d) ) {
2365 dfsVisit(d, toSort, sorted, discovered);
2372 // While we're doing DFS on call graph, remember
2373 // dependencies for efficient queuing of methods
2374 // during interprocedural analysis:
2376 // a dependent of a method decriptor d for this analysis is:
2377 // 1) a method or task that invokes d
2378 // 2) in the descriptorsToAnalyze set
2379 protected void dfsVisit(Descriptor d,
2380 Set <Descriptor> toSort,
2381 LinkedList<Descriptor> sorted,
2382 Set <Descriptor> discovered) {
2385 // only methods have callers, tasks never do
2386 if( d instanceof MethodDescriptor ) {
2388 MethodDescriptor md = (MethodDescriptor) d;
2390 // the call graph is not aware that we have a fabricated
2391 // analysis entry that calls the program source's entry
2392 if( md == mdSourceEntry ) {
2393 if( !discovered.contains(mdAnalysisEntry) ) {
2394 addDependent(mdSourceEntry, // callee
2395 mdAnalysisEntry // caller
2397 dfsVisit(mdAnalysisEntry, toSort, sorted, discovered);
2401 // otherwise call graph guides DFS
2402 Iterator itr = callGraph.getCallerSet(md).iterator();
2403 while( itr.hasNext() ) {
2404 Descriptor dCaller = (Descriptor) itr.next();
2406 // only consider callers in the original set to analyze
2407 if( !toSort.contains(dCaller) ) {
2411 if( !discovered.contains(dCaller) ) {
2412 addDependent(md, // callee
2416 dfsVisit(dCaller, toSort, sorted, discovered);
2421 // for leaf-nodes last now!
2426 protected void enqueue(Descriptor d) {
2428 if( !descriptorsToVisitSet.contains(d) ) {
2430 if( state.DISJOINTDVISITSTACK ||
2431 state.DISJOINTDVISITSTACKEESONTOP
2433 descriptorsToVisitStack.add(d);
2435 } else if( state.DISJOINTDVISITPQUE ) {
2436 Integer priority = mapDescriptorToPriority.get(d);
2437 descriptorsToVisitQ.add(new DescriptorQWrapper(priority,
2442 descriptorsToVisitSet.add(d);
2447 // a dependent of a method decriptor d for this analysis is:
2448 // 1) a method or task that invokes d
2449 // 2) in the descriptorsToAnalyze set
2450 protected void addDependent(Descriptor callee, Descriptor caller) {
2451 Set<Descriptor> deps = mapDescriptorToSetDependents.get(callee);
2452 if( deps == null ) {
2453 deps = new HashSet<Descriptor>();
2456 mapDescriptorToSetDependents.put(callee, deps);
2459 protected Set<Descriptor> getDependents(Descriptor callee) {
2460 Set<Descriptor> deps = mapDescriptorToSetDependents.get(callee);
2461 if( deps == null ) {
2462 deps = new HashSet<Descriptor>();
2463 mapDescriptorToSetDependents.put(callee, deps);
2469 public Hashtable<FlatCall, ReachGraph> getIHMcontributions(Descriptor d) {
2471 Hashtable<FlatCall, ReachGraph> heapsFromCallers =
2472 mapDescriptorToIHMcontributions.get(d);
2474 if( heapsFromCallers == null ) {
2475 heapsFromCallers = new Hashtable<FlatCall, ReachGraph>();
2476 mapDescriptorToIHMcontributions.put(d, heapsFromCallers);
2479 return heapsFromCallers;
2482 public ReachGraph getIHMcontribution(Descriptor d,
2485 Hashtable<FlatCall, ReachGraph> heapsFromCallers =
2486 getIHMcontributions(d);
2488 if( !heapsFromCallers.containsKey(fc) ) {
2492 return heapsFromCallers.get(fc);
2496 public void addIHMcontribution(Descriptor d,
2500 Hashtable<FlatCall, ReachGraph> heapsFromCallers =
2501 getIHMcontributions(d);
2503 // ensure inputs to initial contexts increase monotonically
2504 ReachGraph merged = new ReachGraph();
2506 merged.merge( heapsFromCallers.get( fc ) );
2508 heapsFromCallers.put( fc, merged );
2513 private AllocSite createParameterAllocSite(ReachGraph rg,
2514 TempDescriptor tempDesc,
2520 flatNew = new FlatNew(tempDesc.getType(), // type
2521 tempDesc, // param temp
2522 false, // global alloc?
2523 "param"+tempDesc // disjoint site ID string
2526 flatNew = new FlatNew(tempDesc.getType(), // type
2527 tempDesc, // param temp
2528 false, // global alloc?
2529 null // disjoint site ID string
2533 // create allocation site
2534 AllocSite as = AllocSite.factory(allocationDepth,
2536 flatNew.getDisjointId(),
2539 for (int i = 0; i < allocationDepth; ++i) {
2540 Integer id = generateUniqueHeapRegionNodeID();
2541 as.setIthOldest(i, id);
2542 mapHrnIdToAllocSite.put(id, as);
2544 // the oldest node is a summary node
2545 as.setSummary(generateUniqueHeapRegionNodeID() );
2553 private Set<FieldDescriptor> getFieldSetTobeAnalyzed(TypeDescriptor typeDesc) {
2555 Set<FieldDescriptor> fieldSet=new HashSet<FieldDescriptor>();
2556 if(!typeDesc.isImmutable()) {
2557 ClassDescriptor classDesc = typeDesc.getClassDesc();
2558 for (Iterator it = classDesc.getFields(); it.hasNext(); ) {
2559 FieldDescriptor field = (FieldDescriptor) it.next();
2560 TypeDescriptor fieldType = field.getType();
2561 if (shouldAnalysisTrack(fieldType)) {
2562 fieldSet.add(field);
2570 private HeapRegionNode createMultiDeimensionalArrayHRN(ReachGraph rg, AllocSite alloc, HeapRegionNode srcHRN, FieldDescriptor fd, Hashtable<HeapRegionNode, HeapRegionNode> map, Hashtable<TypeDescriptor, HeapRegionNode> mapToExistingNode, ReachSet alpha) {
2572 int dimCount=fd.getType().getArrayCount();
2573 HeapRegionNode prevNode=null;
2574 HeapRegionNode arrayEntryNode=null;
2575 for(int i=dimCount; i>0; i--) {
2576 TypeDescriptor typeDesc=fd.getType().dereference(); //hack to get instance of type desc
2577 typeDesc.setArrayCount(i);
2578 TempDescriptor tempDesc=new TempDescriptor(typeDesc.getSymbol(),typeDesc);
2579 HeapRegionNode hrnSummary;
2580 if(!mapToExistingNode.containsKey(typeDesc)) {
2585 as = createParameterAllocSite(rg, tempDesc, false);
2587 // make a new reference to allocated node
2589 rg.createNewHeapRegionNode(as.getSummary(), // id or null to generate a new one
2590 false, // single object?
2592 false, // out-of-context?
2593 as.getType(), // type
2594 as, // allocation site
2595 alpha, // inherent reach
2596 alpha, // current reach
2597 ExistPredSet.factory(rg.predTrue), // predicates
2598 tempDesc.toString() // description
2600 rg.id2hrn.put(as.getSummary(),hrnSummary);
2602 mapToExistingNode.put(typeDesc, hrnSummary);
2604 hrnSummary=mapToExistingNode.get(typeDesc);
2607 if(prevNode==null) {
2608 // make a new reference between new summary node and source
2609 RefEdge edgeToSummary = new RefEdge(srcHRN, // source
2612 fd.getSymbol(), // field name
2614 ExistPredSet.factory(rg.predTrue), // predicates
2618 rg.addRefEdge(srcHRN, hrnSummary, edgeToSummary);
2619 prevNode=hrnSummary;
2620 arrayEntryNode=hrnSummary;
2622 // make a new reference between summary nodes of array
2623 RefEdge edgeToSummary = new RefEdge(prevNode, // source
2626 arrayElementFieldName, // field name
2628 ExistPredSet.factory(rg.predTrue), // predicates
2632 rg.addRefEdge(prevNode, hrnSummary, edgeToSummary);
2633 prevNode=hrnSummary;
2638 // create a new obj node if obj has at least one non-primitive field
2639 TypeDescriptor type=fd.getType();
2640 if(getFieldSetTobeAnalyzed(type).size()>0) {
2641 TypeDescriptor typeDesc=type.dereference();
2642 typeDesc.setArrayCount(0);
2643 if(!mapToExistingNode.containsKey(typeDesc)) {
2644 TempDescriptor tempDesc=new TempDescriptor(type.getSymbol(),typeDesc);
2645 AllocSite as = createParameterAllocSite(rg, tempDesc, false);
2646 // make a new reference to allocated node
2647 HeapRegionNode hrnSummary =
2648 rg.createNewHeapRegionNode(as.getSummary(), // id or null to generate a new one
2649 false, // single object?
2651 false, // out-of-context?
2653 as, // allocation site
2654 alpha, // inherent reach
2655 alpha, // current reach
2656 ExistPredSet.factory(rg.predTrue), // predicates
2657 tempDesc.toString() // description
2659 rg.id2hrn.put(as.getSummary(),hrnSummary);
2660 mapToExistingNode.put(typeDesc, hrnSummary);
2661 RefEdge edgeToSummary = new RefEdge(prevNode, // source
2664 arrayElementFieldName, // field name
2666 ExistPredSet.factory(rg.predTrue), // predicates
2669 rg.addRefEdge(prevNode, hrnSummary, edgeToSummary);
2670 prevNode=hrnSummary;
2672 HeapRegionNode hrnSummary=mapToExistingNode.get(typeDesc);
2673 if(prevNode.getReferenceTo(hrnSummary, typeDesc, arrayElementFieldName)==null) {
2674 RefEdge edgeToSummary = new RefEdge(prevNode, // source
2677 arrayElementFieldName, // field name
2679 ExistPredSet.factory(rg.predTrue), // predicates
2682 rg.addRefEdge(prevNode, hrnSummary, edgeToSummary);
2684 prevNode=hrnSummary;
2688 map.put(arrayEntryNode, prevNode);
2689 return arrayEntryNode;
2692 private ReachGraph createInitialTaskReachGraph(FlatMethod fm) {
2693 ReachGraph rg = new ReachGraph();
2694 TaskDescriptor taskDesc = fm.getTask();
2696 for (int idx = 0; idx < taskDesc.numParameters(); idx++) {
2697 Descriptor paramDesc = taskDesc.getParameter(idx);
2698 TypeDescriptor paramTypeDesc = taskDesc.getParamType(idx);
2700 // setup data structure
2701 Set<HashMap<HeapRegionNode, FieldDescriptor>> workSet =
2702 new HashSet<HashMap<HeapRegionNode, FieldDescriptor>>();
2703 Hashtable<TypeDescriptor, HeapRegionNode> mapTypeToExistingSummaryNode =
2704 new Hashtable<TypeDescriptor, HeapRegionNode>();
2705 Hashtable<HeapRegionNode, HeapRegionNode> mapToFirstDimensionArrayNode =
2706 new Hashtable<HeapRegionNode, HeapRegionNode>();
2707 Set<String> doneSet = new HashSet<String>();
2709 TempDescriptor tempDesc = fm.getParameter(idx);
2711 AllocSite as = createParameterAllocSite(rg, tempDesc, true);
2712 VariableNode lnX = rg.getVariableNodeFromTemp(tempDesc);
2713 Integer idNewest = as.getIthOldest(0);
2714 HeapRegionNode hrnNewest = rg.id2hrn.get(idNewest);
2716 // make a new reference to allocated node
2717 RefEdge edgeNew = new RefEdge(lnX, // source
2719 taskDesc.getParamType(idx), // type
2721 hrnNewest.getAlpha(), // beta
2722 ExistPredSet.factory(rg.predTrue), // predicates
2725 rg.addRefEdge(lnX, hrnNewest, edgeNew);
2727 // set-up a work set for class field
2728 ClassDescriptor classDesc = paramTypeDesc.getClassDesc();
2729 for (Iterator it = classDesc.getFields(); it.hasNext(); ) {
2730 FieldDescriptor fd = (FieldDescriptor) it.next();
2731 TypeDescriptor fieldType = fd.getType();
2732 if (shouldAnalysisTrack(fieldType)) {
2733 HashMap<HeapRegionNode, FieldDescriptor> newMap = new HashMap<HeapRegionNode, FieldDescriptor>();
2734 newMap.put(hrnNewest, fd);
2735 workSet.add(newMap);
2739 int uniqueIdentifier = 0;
2740 while (!workSet.isEmpty()) {
2741 HashMap<HeapRegionNode, FieldDescriptor> map = workSet
2743 workSet.remove(map);
2745 Set<HeapRegionNode> key = map.keySet();
2746 HeapRegionNode srcHRN = key.iterator().next();
2747 FieldDescriptor fd = map.get(srcHRN);
2748 TypeDescriptor type = fd.getType();
2749 String doneSetIdentifier = srcHRN.getIDString() + "_" + fd;
2751 if (!doneSet.contains(doneSetIdentifier)) {
2752 doneSet.add(doneSetIdentifier);
2753 if (!mapTypeToExistingSummaryNode.containsKey(type)) {
2754 // create new summary Node
2755 TempDescriptor td = new TempDescriptor("temp"
2756 + uniqueIdentifier, type);
2758 AllocSite allocSite;
2759 if(type.equals(paramTypeDesc)) {
2760 //corresponding allocsite has already been created for a parameter variable.
2763 allocSite = createParameterAllocSite(rg, td, false);
2765 String strDesc = allocSite.toStringForDOT()
2767 TypeDescriptor allocType=allocSite.getType();
2769 HeapRegionNode hrnSummary;
2770 if(allocType.isArray() && allocType.getArrayCount()>0) {
2771 hrnSummary=createMultiDeimensionalArrayHRN(rg,allocSite,srcHRN,fd,mapToFirstDimensionArrayNode,mapTypeToExistingSummaryNode,hrnNewest.getAlpha());
2774 rg.createNewHeapRegionNode(allocSite.getSummary(), // id or null to generate a new one
2775 false, // single object?
2777 false, // out-of-context?
2778 allocSite.getType(), // type
2779 allocSite, // allocation site
2780 hrnNewest.getAlpha(), // inherent reach
2781 hrnNewest.getAlpha(), // current reach
2782 ExistPredSet.factory(rg.predTrue), // predicates
2783 strDesc // description
2785 rg.id2hrn.put(allocSite.getSummary(),hrnSummary);
2787 // make a new reference to summary node
2788 RefEdge edgeToSummary = new RefEdge(srcHRN, // source
2791 fd.getSymbol(), // field name
2792 hrnNewest.getAlpha(), // beta
2793 ExistPredSet.factory(rg.predTrue), // predicates
2797 rg.addRefEdge(srcHRN, hrnSummary, edgeToSummary);
2801 mapTypeToExistingSummaryNode.put(type, hrnSummary);
2803 // set-up a work set for fields of the class
2804 Set<FieldDescriptor> fieldTobeAnalyzed=getFieldSetTobeAnalyzed(type);
2805 for (Iterator iterator = fieldTobeAnalyzed.iterator(); iterator
2807 FieldDescriptor fieldDescriptor = (FieldDescriptor) iterator
2809 HeapRegionNode newDstHRN;
2810 if(mapToFirstDimensionArrayNode.containsKey(hrnSummary)) {
2811 //related heap region node is already exsited.
2812 newDstHRN=mapToFirstDimensionArrayNode.get(hrnSummary);
2814 newDstHRN=hrnSummary;
2816 doneSetIdentifier = newDstHRN.getIDString() + "_" + fieldDescriptor;
2817 if(!doneSet.contains(doneSetIdentifier)) {
2818 // add new work item
2819 HashMap<HeapRegionNode, FieldDescriptor> newMap =
2820 new HashMap<HeapRegionNode, FieldDescriptor>();
2821 newMap.put(newDstHRN, fieldDescriptor);
2822 workSet.add(newMap);
2827 // if there exists corresponding summary node
2828 HeapRegionNode hrnDst=mapTypeToExistingSummaryNode.get(type);
2830 RefEdge edgeToSummary = new RefEdge(srcHRN, // source
2832 fd.getType(), // type
2833 fd.getSymbol(), // field name
2834 srcHRN.getAlpha(), // beta
2835 ExistPredSet.factory(rg.predTrue), // predicates
2838 rg.addRefEdge(srcHRN, hrnDst, edgeToSummary);
2848 // return all allocation sites in the method (there is one allocation
2849 // site per FlatNew node in a method)
2850 private HashSet<AllocSite> getAllocationSiteSet(Descriptor d) {
2851 if( !mapDescriptorToAllocSiteSet.containsKey(d) ) {
2852 buildAllocationSiteSet(d);
2855 return mapDescriptorToAllocSiteSet.get(d);
2859 private void buildAllocationSiteSet(Descriptor d) {
2860 HashSet<AllocSite> s = new HashSet<AllocSite>();
2863 if( d instanceof MethodDescriptor ) {
2864 fm = state.getMethodFlat( (MethodDescriptor) d);
2866 assert d instanceof TaskDescriptor;
2867 fm = state.getMethodFlat( (TaskDescriptor) d);
2869 pm.analyzeMethod(fm);
2871 // visit every node in this FlatMethod's IR graph
2872 // and make a set of the allocation sites from the
2873 // FlatNew node's visited
2874 HashSet<FlatNode> visited = new HashSet<FlatNode>();
2875 HashSet<FlatNode> toVisit = new HashSet<FlatNode>();
2878 while( !toVisit.isEmpty() ) {
2879 FlatNode n = toVisit.iterator().next();
2881 if( n instanceof FlatNew ) {
2882 s.add(getAllocSiteFromFlatNewPRIVATE( (FlatNew) n) );
2888 for( int i = 0; i < pm.numNext(n); ++i ) {
2889 FlatNode child = pm.getNext(n, i);
2890 if( !visited.contains(child) ) {
2896 mapDescriptorToAllocSiteSet.put(d, s);
2899 private HashSet<AllocSite> getFlaggedAllocationSites(Descriptor dIn) {
2901 HashSet<AllocSite> out = new HashSet<AllocSite>();
2902 HashSet<Descriptor> toVisit = new HashSet<Descriptor>();
2903 HashSet<Descriptor> visited = new HashSet<Descriptor>();
2907 while (!toVisit.isEmpty()) {
2908 Descriptor d = toVisit.iterator().next();
2912 HashSet<AllocSite> asSet = getAllocationSiteSet(d);
2913 Iterator asItr = asSet.iterator();
2914 while (asItr.hasNext()) {
2915 AllocSite as = (AllocSite) asItr.next();
2916 if (as.getDisjointAnalysisId() != null) {
2921 // enqueue callees of this method to be searched for
2922 // allocation sites also
2923 Set callees = callGraph.getCalleeSet(d);
2924 if (callees != null) {
2925 Iterator methItr = callees.iterator();
2926 while (methItr.hasNext()) {
2927 MethodDescriptor md = (MethodDescriptor) methItr.next();
2929 if (!visited.contains(md)) {
2940 private HashSet<AllocSite>
2941 getFlaggedAllocationSitesReachableFromTaskPRIVATE(TaskDescriptor td) {
2943 HashSet<AllocSite> asSetTotal = new HashSet<AllocSite>();
2944 HashSet<Descriptor> toVisit = new HashSet<Descriptor>();
2945 HashSet<Descriptor> visited = new HashSet<Descriptor>();
2949 // traverse this task and all methods reachable from this task
2950 while( !toVisit.isEmpty() ) {
2951 Descriptor d = toVisit.iterator().next();
2955 HashSet<AllocSite> asSet = getAllocationSiteSet(d);
2956 Iterator asItr = asSet.iterator();
2957 while( asItr.hasNext() ) {
2958 AllocSite as = (AllocSite) asItr.next();
2959 TypeDescriptor typed = as.getType();
2960 if( typed != null ) {
2961 ClassDescriptor cd = typed.getClassDesc();
2962 if( cd != null && cd.hasFlags() ) {
2968 // enqueue callees of this method to be searched for
2969 // allocation sites also
2970 Set callees = callGraph.getCalleeSet(d);
2971 if( callees != null ) {
2972 Iterator methItr = callees.iterator();
2973 while( methItr.hasNext() ) {
2974 MethodDescriptor md = (MethodDescriptor) methItr.next();
2976 if( !visited.contains(md) ) {
2986 public Set<Descriptor> getDescriptorsToAnalyze() {
2987 return descriptorsToAnalyze;
2990 public EffectsAnalysis getEffectsAnalysis() {
2991 return effectsAnalysis;
2994 public ReachGraph getReachGraph(Descriptor d) {
2995 return mapDescriptorToCompleteReachGraph.get(d);
2998 public ReachGraph getEnterReachGraph(FlatNode fn) {
2999 return fn2rgAtEnter.get(fn);
3004 protected class DebugCallSiteData {
3005 public boolean debugCallSite;
3006 public boolean didOneDebug;
3007 public boolean writeDebugDOTs;
3008 public boolean stopAfter;
3010 public DebugCallSiteData() {
3011 debugCallSite = false;
3012 didOneDebug = false;
3013 writeDebugDOTs = false;
3018 protected void decideDebugCallSite( DebugCallSiteData dcsd,
3019 Descriptor taskOrMethodCaller,
3020 MethodDescriptor mdCallee ) {
3022 // all this jimma jamma to debug call sites is WELL WORTH the
3023 // effort, so so so many bugs or buggy info appears through call
3026 if( state.DISJOINTDEBUGCALLEE == null ||
3027 state.DISJOINTDEBUGCALLER == null ) {
3032 boolean debugCalleeMatches = false;
3033 boolean debugCallerMatches = false;
3035 ClassDescriptor cdCallee = mdCallee.getClassDesc();
3036 if( cdCallee != null ) {
3037 debugCalleeMatches =
3038 state.DISJOINTDEBUGCALLEE.equals( cdCallee.getSymbol()+
3040 mdCallee.getSymbol()
3045 if( taskOrMethodCaller instanceof MethodDescriptor ) {
3046 ClassDescriptor cdCaller = ((MethodDescriptor)taskOrMethodCaller).getClassDesc();
3047 if( cdCaller != null ) {
3048 debugCallerMatches =
3049 state.DISJOINTDEBUGCALLER.equals( cdCaller.getSymbol()+
3051 taskOrMethodCaller.getSymbol()
3055 // for bristlecone style tasks
3056 debugCallerMatches =
3057 state.DISJOINTDEBUGCALLER.equals( taskOrMethodCaller.getSymbol() );
3061 dcsd.debugCallSite = debugCalleeMatches && debugCallerMatches;
3064 dcsd.writeDebugDOTs =
3066 dcsd.debugCallSite &&
3068 (ReachGraph.debugCallSiteVisitCounter >=
3069 ReachGraph.debugCallSiteVisitStartCapture) &&
3071 (ReachGraph.debugCallSiteVisitCounter <
3072 ReachGraph.debugCallSiteVisitStartCapture +
3073 ReachGraph.debugCallSiteNumVisitsToCapture);
3077 if( dcsd.debugCallSite ) {
3078 dcsd.didOneDebug = true;
3082 protected void statusDebugCallSite( DebugCallSiteData dcsd ) {
3084 dcsd.writeDebugDOTs = false;
3085 dcsd.stopAfter = false;
3087 if( dcsd.didOneDebug ) {
3088 System.out.println(" $$$ Debug call site visit "+
3089 ReachGraph.debugCallSiteVisitCounter+
3093 (ReachGraph.debugCallSiteVisitCounter >=
3094 ReachGraph.debugCallSiteVisitStartCapture) &&
3096 (ReachGraph.debugCallSiteVisitCounter <
3097 ReachGraph.debugCallSiteVisitStartCapture +
3098 ReachGraph.debugCallSiteNumVisitsToCapture)
3100 dcsd.writeDebugDOTs = true;
3101 System.out.println(" $$$ Capturing this call site visit $$$");
3102 if( ReachGraph.debugCallSiteStopAfter &&
3103 (ReachGraph.debugCallSiteVisitCounter ==
3104 ReachGraph.debugCallSiteVisitStartCapture +
3105 ReachGraph.debugCallSiteNumVisitsToCapture - 1)
3107 dcsd.stopAfter = true;
3111 ++ReachGraph.debugCallSiteVisitCounter;
3114 if( dcsd.stopAfter ) {
3115 System.out.println("$$$ Exiting after requested captures of call site. $$$");
3124 // get successive captures of the analysis state, use compiler
3126 boolean takeDebugSnapshots = false;
3127 String descSymbolDebug = null;
3128 boolean stopAfterCapture = false;
3129 int snapVisitCounter = 0;
3130 int snapNodeCounter = 0;
3131 int visitStartCapture = 0;
3132 int numVisitsToCapture = 0;
3135 void debugSnapshot(ReachGraph rg, FlatNode fn, boolean in) {
3136 if( snapVisitCounter > visitStartCapture + numVisitsToCapture ) {
3144 if( snapVisitCounter >= visitStartCapture ) {
3145 System.out.println(" @@@ snapping visit="+snapVisitCounter+
3146 ", node="+snapNodeCounter+
3150 graphName = String.format("snap%03d_%04din",
3154 graphName = String.format("snap%03d_%04dout",
3159 graphName = graphName + fn;
3161 rg.writeGraph(graphName,
3162 true, // write labels (variables)
3163 true, // selectively hide intermediate temp vars
3164 true, // prune unreachable heap regions
3165 false, // hide reachability
3166 true, // hide subset reachability states
3167 true, // hide predicates
3168 true); // hide edge taints
3175 public Set<Alloc> canPointToAt( TempDescriptor x,
3176 FlatNode programPoint ) {
3178 ReachGraph rgAtEnter = fn2rgAtEnter.get( programPoint );
3179 if( rgAtEnter == null ) {
3183 return rgAtEnter.canPointTo( x );
3187 public Hashtable< Alloc, Set<Alloc> > canPointToAt( TempDescriptor x,
3189 FlatNode programPoint ) {
3191 ReachGraph rgAtEnter = fn2rgAtEnter.get( programPoint );
3192 if( rgAtEnter == null ) {
3196 return rgAtEnter.canPointTo( x, f.getSymbol(), f.getType() );
3200 public Hashtable< Alloc, Set<Alloc> > canPointToAtElement( TempDescriptor x,
3201 FlatNode programPoint ) {
3203 ReachGraph rgAtEnter = fn2rgAtEnter.get( programPoint );
3204 if( rgAtEnter == null ) {
3208 assert x.getType() != null;
3209 assert x.getType().isArray();
3211 return rgAtEnter.canPointTo( x, arrayElementFieldName, x.getType().dereference() );
3215 public Set<Alloc> canPointToAfter( TempDescriptor x,
3216 FlatNode programPoint ) {
3218 ReachGraph rgAtExit = fn2rgAtExit.get( programPoint );
3220 if( rgAtExit == null ) {
3224 return rgAtExit.canPointTo( x );
3228 public Hashtable< Alloc, Set<Alloc> > canPointToAfter( TempDescriptor x,
3230 FlatNode programPoint ) {
3232 ReachGraph rgAtExit = fn2rgAtExit.get( programPoint );
3233 if( rgAtExit == null ) {
3237 return rgAtExit.canPointTo( x, f.getSymbol(), f.getType() );
3241 public Hashtable< Alloc, Set<Alloc> > canPointToAfterElement( TempDescriptor x,
3242 FlatNode programPoint ) {
3244 ReachGraph rgAtExit = fn2rgAtExit.get( programPoint );
3245 if( rgAtExit == null ) {
3249 assert x.getType() != null;
3250 assert x.getType().isArray();
3252 return rgAtExit.canPointTo( x, arrayElementFieldName, x.getType().dereference() );