summaryrefslogtreecommitdiff
path: root/clang/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
blob: 01dd965ac55a916e2948387b4f58543dd9a86c6e (about) (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
//===--- PathDiagnostic.cpp - Path-Specific Diagnostic Handling -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the PathDiagnostic-related interfaces.
//
//===----------------------------------------------------------------------===//

#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
#include "clang/Basic/SourceManager.h"
#include "clang/AST/Expr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ParentMap.h"
#include "clang/AST/StmtCXX.h"
#include "llvm/ADT/SmallString.h"

using namespace clang;
using namespace ento;

bool PathDiagnosticMacroPiece::containsEvent() const {
  for (PathPieces::const_iterator I = subPieces.begin(), E = subPieces.end();
       I!=E; ++I) {
    if (isa<PathDiagnosticEventPiece>(*I))
      return true;
    if (PathDiagnosticMacroPiece *MP = dyn_cast<PathDiagnosticMacroPiece>(*I))
      if (MP->containsEvent())
        return true;
  }
  return false;
}

static StringRef StripTrailingDots(StringRef s) {
  for (StringRef::size_type i = s.size(); i != 0; --i)
    if (s[i - 1] != '.')
      return s.substr(0, i);
  return "";
}

PathDiagnosticPiece::PathDiagnosticPiece(StringRef s,
                                         Kind k, DisplayHint hint)
  : str(StripTrailingDots(s)), kind(k), Hint(hint) {}

PathDiagnosticPiece::PathDiagnosticPiece(Kind k, DisplayHint hint)
  : kind(k), Hint(hint) {}

PathDiagnosticPiece::~PathDiagnosticPiece() {}
PathDiagnosticEventPiece::~PathDiagnosticEventPiece() {}
PathDiagnosticCallPiece::~PathDiagnosticCallPiece() {}
PathDiagnosticControlFlowPiece::~PathDiagnosticControlFlowPiece() {}
PathDiagnosticMacroPiece::~PathDiagnosticMacroPiece() {}


PathPieces::~PathPieces() {}
PathDiagnostic::~PathDiagnostic() {}

PathDiagnostic::PathDiagnostic(const Decl *declWithIssue,
                               StringRef bugtype, StringRef desc,
                               StringRef category)
  : DeclWithIssue(declWithIssue),
    BugType(StripTrailingDots(bugtype)),
    Desc(StripTrailingDots(desc)),
    Category(StripTrailingDots(category)),
    path(pathImpl) {}

void PathDiagnosticConsumer::anchor() { }

PathDiagnosticConsumer::~PathDiagnosticConsumer() {
  // Delete the contents of the FoldingSet if it isn't empty already.
  for (llvm::FoldingSet<PathDiagnostic>::iterator it =
       Diags.begin(), et = Diags.end() ; it != et ; ++it) {
    delete &*it;
  }
}

void PathDiagnosticConsumer::HandlePathDiagnostic(PathDiagnostic *D) {
  llvm::OwningPtr<PathDiagnostic> OwningD(D);
  
  if (!D || D->path.empty())
    return;
  
  // We need to flatten the locations (convert Stmt* to locations) because
  // the referenced statements may be freed by the time the diagnostics
  // are emitted.
  D->flattenLocations();

  // If the PathDiagnosticConsumer does not support diagnostics that
  // cross file boundaries, prune out such diagnostics now.
  if (!supportsCrossFileDiagnostics()) {
    // Verify that the entire path is from the same FileID.
    FileID FID;
    const SourceManager &SMgr = (*D->path.begin())->getLocation().getManager();
    llvm::SmallVector<const PathPieces *, 5> WorkList;
    WorkList.push_back(&D->path);

    while (!WorkList.empty()) {
      const PathPieces &path = *WorkList.back();
      WorkList.pop_back();

      for (PathPieces::const_iterator I = path.begin(), E = path.end();
           I != E; ++I) {
        const PathDiagnosticPiece *piece = I->getPtr();
        FullSourceLoc L = piece->getLocation().asLocation().getExpansionLoc();
      
        if (FID.isInvalid()) {
          FID = SMgr.getFileID(L);
        } else if (SMgr.getFileID(L) != FID)
          return; // FIXME: Emit a warning?
      
        // Check the source ranges.
        for (PathDiagnosticPiece::range_iterator RI = piece->ranges_begin(),
             RE = piece->ranges_end();
             RI != RE; ++RI) {
          SourceLocation L = SMgr.getExpansionLoc(RI->getBegin());
          if (!L.isFileID() || SMgr.getFileID(L) != FID)
            return; // FIXME: Emit a warning?
          L = SMgr.getExpansionLoc(RI->getEnd());
          if (!L.isFileID() || SMgr.getFileID(L) != FID)
            return; // FIXME: Emit a warning?
        }
        
        if (const PathDiagnosticCallPiece *call =
            dyn_cast<PathDiagnosticCallPiece>(piece)) {
          WorkList.push_back(&call->path);
        }
        else if (const PathDiagnosticMacroPiece *macro =
                 dyn_cast<PathDiagnosticMacroPiece>(piece)) {
          WorkList.push_back(&macro->subPieces);
        }
      }
    }
    
    if (FID.isInvalid())
      return; // FIXME: Emit a warning?
  }  

  // Profile the node to see if we already have something matching it
  llvm::FoldingSetNodeID profile;
  D->Profile(profile);
  void *InsertPos = 0;

  if (PathDiagnostic *orig = Diags.FindNodeOrInsertPos(profile, InsertPos)) {
    // Keep the PathDiagnostic with the shorter path.
    const unsigned orig_size = orig->full_size();
    const unsigned new_size = D->full_size();
    
    if (orig_size <= new_size) {
      bool shouldKeepOriginal = true;
      if (orig_size == new_size) {
        // Here we break ties in a fairly arbitrary, but deterministic, way.
        llvm::FoldingSetNodeID fullProfile, fullProfileOrig;
        D->FullProfile(fullProfile);
        orig->FullProfile(fullProfileOrig);
        if (fullProfile.ComputeHash() < fullProfileOrig.ComputeHash())
          shouldKeepOriginal = false;
      }

      if (shouldKeepOriginal)
        return;
    }
    Diags.RemoveNode(orig);
    delete orig;
  }
  
  Diags.InsertNode(OwningD.take());
}


namespace {
struct CompareDiagnostics {
  // Compare if 'X' is "<" than 'Y'.
  bool operator()(const PathDiagnostic *X, const PathDiagnostic *Y) const {
    // First compare by location
    const FullSourceLoc &XLoc = X->getLocation().asLocation();
    const FullSourceLoc &YLoc = Y->getLocation().asLocation();
    if (XLoc < YLoc)
      return true;
    if (XLoc != YLoc)
      return false;
    
    // Next, compare by bug type.
    StringRef XBugType = X->getBugType();
    StringRef YBugType = Y->getBugType();
    if (XBugType < YBugType)
      return true;
    if (XBugType != YBugType)
      return false;
    
    // Next, compare by bug description.
    StringRef XDesc = X->getDescription();
    StringRef YDesc = Y->getDescription();
    if (XDesc < YDesc)
      return true;
    if (XDesc != YDesc)
      return false;
    
    // FIXME: Further refine by comparing PathDiagnosticPieces?
    return false;    
  }  
};  
}

void
PathDiagnosticConsumer::FlushDiagnostics(SmallVectorImpl<std::string> *Files) {
  if (flushed)
    return;
  
  flushed = true;
  
  std::vector<const PathDiagnostic *> BatchDiags;
  for (llvm::FoldingSet<PathDiagnostic>::iterator it = Diags.begin(),
       et = Diags.end(); it != et; ++it) {
    BatchDiags.push_back(&*it);
  }
  
  // Clear out the FoldingSet.
  Diags.clear();

  // Sort the diagnostics so that they are always emitted in a deterministic
  // order.
  if (!BatchDiags.empty())
    std::sort(BatchDiags.begin(), BatchDiags.end(), CompareDiagnostics());
  
  FlushDiagnosticsImpl(BatchDiags, Files);

  // Delete the flushed diagnostics.
  for (std::vector<const PathDiagnostic *>::iterator it = BatchDiags.begin(),
       et = BatchDiags.end(); it != et; ++it) {
    const PathDiagnostic *D = *it;
    delete D;
  }
}

//===----------------------------------------------------------------------===//
// PathDiagnosticLocation methods.
//===----------------------------------------------------------------------===//

static SourceLocation getValidSourceLocation(const Stmt* S,
                                             LocationOrAnalysisDeclContext LAC) {
  SourceLocation L = S->getLocStart();
  assert(!LAC.isNull() && "A valid LocationContext or AnalysisDeclContext should "
                          "be passed to PathDiagnosticLocation upon creation.");

  // S might be a temporary statement that does not have a location in the
  // source code, so find an enclosing statement and use it's location.
  if (!L.isValid()) {

    ParentMap *PM = 0;
    if (LAC.is<const LocationContext*>())
      PM = &LAC.get<const LocationContext*>()->getParentMap();
    else
      PM = &LAC.get<AnalysisDeclContext*>()->getParentMap();

    while (!L.isValid()) {
      S = PM->getParent(S);
      L = S->getLocStart();
    }
  }

  return L;
}

PathDiagnosticLocation
  PathDiagnosticLocation::createBegin(const Decl *D,
                                      const SourceManager &SM) {
  return PathDiagnosticLocation(D->getLocStart(), SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::createBegin(const Stmt *S,
                                      const SourceManager &SM,
                                      LocationOrAnalysisDeclContext LAC) {
  return PathDiagnosticLocation(getValidSourceLocation(S, LAC),
                                SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::createOperatorLoc(const BinaryOperator *BO,
                                            const SourceManager &SM) {
  return PathDiagnosticLocation(BO->getOperatorLoc(), SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::createMemberLoc(const MemberExpr *ME,
                                          const SourceManager &SM) {
  return PathDiagnosticLocation(ME->getMemberLoc(), SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::createBeginBrace(const CompoundStmt *CS,
                                           const SourceManager &SM) {
  SourceLocation L = CS->getLBracLoc();
  return PathDiagnosticLocation(L, SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::createEndBrace(const CompoundStmt *CS,
                                         const SourceManager &SM) {
  SourceLocation L = CS->getRBracLoc();
  return PathDiagnosticLocation(L, SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::createDeclBegin(const LocationContext *LC,
                                          const SourceManager &SM) {
  // FIXME: Should handle CXXTryStmt if analyser starts supporting C++.
  if (const CompoundStmt *CS =
        dyn_cast_or_null<CompoundStmt>(LC->getDecl()->getBody()))
    if (!CS->body_empty()) {
      SourceLocation Loc = (*CS->body_begin())->getLocStart();
      return PathDiagnosticLocation(Loc, SM, SingleLocK);
    }

  return PathDiagnosticLocation();
}

PathDiagnosticLocation
  PathDiagnosticLocation::createDeclEnd(const LocationContext *LC,
                                        const SourceManager &SM) {
  SourceLocation L = LC->getDecl()->getBodyRBrace();
  return PathDiagnosticLocation(L, SM, SingleLocK);
}

PathDiagnosticLocation
  PathDiagnosticLocation::create(const ProgramPoint& P,
                                 const SourceManager &SMng) {

  const Stmt* S = 0;
  if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
    const CFGBlock *BSrc = BE->getSrc();
    S = BSrc->getTerminatorCondition();
  }
  else if (const PostStmt *PS = dyn_cast<PostStmt>(&P)) {
    S = PS->getStmt();
  }

  return PathDiagnosticLocation(S, SMng, P.getLocationContext());
}

PathDiagnosticLocation
  PathDiagnosticLocation::createEndOfPath(const ExplodedNode* N,
                                          const SourceManager &SM) {
  assert(N && "Cannot create a location with a null node.");

  const ExplodedNode *NI = N;

  while (NI) {
    ProgramPoint P = NI->getLocation();
    const LocationContext *LC = P.getLocationContext();
    if (const StmtPoint *PS = dyn_cast<StmtPoint>(&P))
      return PathDiagnosticLocation(PS->getStmt(), SM, LC);
    else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
      const Stmt *Term = BE->getSrc()->getTerminator();
      if (Term) {
        return PathDiagnosticLocation(Term, SM, LC);
      }
    }
    NI = NI->succ_empty() ? 0 : *(NI->succ_begin());
  }

  return createDeclEnd(N->getLocationContext(), SM);
}

PathDiagnosticLocation PathDiagnosticLocation::createSingleLocation(
                                           const PathDiagnosticLocation &PDL) {
  FullSourceLoc L = PDL.asLocation();
  return PathDiagnosticLocation(L, L.getManager(), SingleLocK);
}

FullSourceLoc
  PathDiagnosticLocation::genLocation(SourceLocation L,
                                      LocationOrAnalysisDeclContext LAC) const {
  assert(isValid());
  // Note that we want a 'switch' here so that the compiler can warn us in
  // case we add more cases.
  switch (K) {
    case SingleLocK:
    case RangeK:
      break;
    case StmtK:
      // Defensive checking.
      if (!S)
        break;
      return FullSourceLoc(getValidSourceLocation(S, LAC),
                           const_cast<SourceManager&>(*SM));
    case DeclK:
      // Defensive checking.
      if (!D)
        break;
      return FullSourceLoc(D->getLocation(), const_cast<SourceManager&>(*SM));
  }

  return FullSourceLoc(L, const_cast<SourceManager&>(*SM));
}

PathDiagnosticRange
  PathDiagnosticLocation::genRange(LocationOrAnalysisDeclContext LAC) const {
  assert(isValid());
  // Note that we want a 'switch' here so that the compiler can warn us in
  // case we add more cases.
  switch (K) {
    case SingleLocK:
      return PathDiagnosticRange(SourceRange(Loc,Loc), true);
    case RangeK:
      break;
    case StmtK: {
      const Stmt *S = asStmt();
      switch (S->getStmtClass()) {
        default:
          break;
        case Stmt::DeclStmtClass: {
          const DeclStmt *DS = cast<DeclStmt>(S);
          if (DS->isSingleDecl()) {
            // Should always be the case, but we'll be defensive.
            return SourceRange(DS->getLocStart(),
                               DS->getSingleDecl()->getLocation());
          }
          break;
        }
          // FIXME: Provide better range information for different
          //  terminators.
        case Stmt::IfStmtClass:
        case Stmt::WhileStmtClass:
        case Stmt::DoStmtClass:
        case Stmt::ForStmtClass:
        case Stmt::ChooseExprClass:
        case Stmt::IndirectGotoStmtClass:
        case Stmt::SwitchStmtClass:
        case Stmt::BinaryConditionalOperatorClass:
        case Stmt::ConditionalOperatorClass:
        case Stmt::ObjCForCollectionStmtClass: {
          SourceLocation L = getValidSourceLocation(S, LAC);
          return SourceRange(L, L);
        }
      }
      SourceRange R = S->getSourceRange();
      if (R.isValid())
        return R;
      break;  
    }
    case DeclK:
      if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D))
        return MD->getSourceRange();
      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
        if (Stmt *Body = FD->getBody())
          return Body->getSourceRange();
      }
      else {
        SourceLocation L = D->getLocation();
        return PathDiagnosticRange(SourceRange(L, L), true);
      }
  }

  return SourceRange(Loc,Loc);
}

void PathDiagnosticLocation::flatten() {
  if (K == StmtK) {
    K = RangeK;
    S = 0;
    D = 0;
  }
  else if (K == DeclK) {
    K = SingleLocK;
    S = 0;
    D = 0;
  }
}

PathDiagnosticLocation PathDiagnostic::getLocation() const {
  assert(path.size() > 0 &&
         "getLocation() requires a non-empty PathDiagnostic.");
  
  PathDiagnosticPiece *p = path.rbegin()->getPtr();
  
  while (true) {
    if (PathDiagnosticCallPiece *cp = dyn_cast<PathDiagnosticCallPiece>(p)) {
      assert(!cp->path.empty());
      p = cp->path.rbegin()->getPtr();
      continue;
    }
    break;
  }
  
  return p->getLocation();
}

//===----------------------------------------------------------------------===//
// Manipulation of PathDiagnosticCallPieces.
//===----------------------------------------------------------------------===//

static PathDiagnosticLocation getLastStmtLoc(const ExplodedNode *N,
                                             const SourceManager &SM) {
  while (N) {
    ProgramPoint PP = N->getLocation();
    if (const StmtPoint *SP = dyn_cast<StmtPoint>(&PP))
      return PathDiagnosticLocation(SP->getStmt(), SM, PP.getLocationContext());
    if (N->pred_empty())
      break;
    N = *N->pred_begin();
  }
  return PathDiagnosticLocation();
}

PathDiagnosticCallPiece *
PathDiagnosticCallPiece::construct(const ExplodedNode *N,
                                   const CallExit &CE,
                                   const SourceManager &SM) {
  const Decl *caller = CE.getLocationContext()->getParent()->getDecl();
  PathDiagnosticLocation pos = getLastStmtLoc(N, SM);
  return new PathDiagnosticCallPiece(caller, pos);
}

PathDiagnosticCallPiece *
PathDiagnosticCallPiece::construct(PathPieces &path,
                                   const Decl *caller) {
  PathDiagnosticCallPiece *C = new PathDiagnosticCallPiece(path, caller);
  path.clear();
  path.push_front(C);
  return C;
}

void PathDiagnosticCallPiece::setCallee(const CallEnter &CE,
                                        const SourceManager &SM) {
  const Decl *D = CE.getCalleeContext()->getDecl();
  Callee = D;
  callEnter = PathDiagnosticLocation(CE.getCallExpr(), SM,
                                     CE.getLocationContext());
  callEnterWithin = PathDiagnosticLocation::createBegin(D, SM);
}

IntrusiveRefCntPtr<PathDiagnosticEventPiece>
PathDiagnosticCallPiece::getCallEnterEvent() const {
  if (!Callee)
    return 0;  
  SmallString<256> buf;
  llvm::raw_svector_ostream Out(buf);
  if (isa<BlockDecl>(Callee))
    Out << "Calling anonymous block";
  else if (const NamedDecl *ND = dyn_cast<NamedDecl>(Callee))
    Out << "Calling '" << *ND << "'";
  StringRef msg = Out.str();
  if (msg.empty())
    return 0;
  return new PathDiagnosticEventPiece(callEnter, msg);
}

IntrusiveRefCntPtr<PathDiagnosticEventPiece>
PathDiagnosticCallPiece::getCallEnterWithinCallerEvent() const {
  SmallString<256> buf;
  llvm::raw_svector_ostream Out(buf);
  if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(Caller))
    Out << "Entered call from '" << *ND << "'";
  else
    Out << "Entered call";
  StringRef msg = Out.str();
  if (msg.empty())
    return 0;
  return new PathDiagnosticEventPiece(callEnterWithin, msg);
}

IntrusiveRefCntPtr<PathDiagnosticEventPiece>
PathDiagnosticCallPiece::getCallExitEvent() const {
  if (NoExit)
    return 0;
  SmallString<256> buf;
  llvm::raw_svector_ostream Out(buf);
  if (!CallStackMessage.empty())
    Out << CallStackMessage;
  else if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(Callee))
    Out << "Returning from '" << *ND << "'";
  else
    Out << "Returning to caller";
  return new PathDiagnosticEventPiece(callReturn, Out.str());
}

static void compute_path_size(const PathPieces &pieces, unsigned &size) {
  for (PathPieces::const_iterator it = pieces.begin(),
                                  et = pieces.end(); it != et; ++it) {
    const PathDiagnosticPiece *piece = it->getPtr();
    if (const PathDiagnosticCallPiece *cp = 
        dyn_cast<PathDiagnosticCallPiece>(piece)) {
      compute_path_size(cp->path, size);
    }
    else
      ++size;
  }
}

unsigned PathDiagnostic::full_size() {
  unsigned size = 0;
  compute_path_size(path, size);
  return size;
}

//===----------------------------------------------------------------------===//
// FoldingSet profiling methods.
//===----------------------------------------------------------------------===//

void PathDiagnosticLocation::Profile(llvm::FoldingSetNodeID &ID) const {
  ID.AddInteger(Range.getBegin().getRawEncoding());
  ID.AddInteger(Range.getEnd().getRawEncoding());
  ID.AddInteger(Loc.getRawEncoding());
  return;
}

void PathDiagnosticPiece::Profile(llvm::FoldingSetNodeID &ID) const {
  ID.AddInteger((unsigned) getKind());
  ID.AddString(str);
  // FIXME: Add profiling support for code hints.
  ID.AddInteger((unsigned) getDisplayHint());
  for (range_iterator I = ranges_begin(), E = ranges_end(); I != E; ++I) {
    ID.AddInteger(I->getBegin().getRawEncoding());
    ID.AddInteger(I->getEnd().getRawEncoding());
  }  
}

void PathDiagnosticCallPiece::Profile(llvm::FoldingSetNodeID &ID) const {
  PathDiagnosticPiece::Profile(ID);
  for (PathPieces::const_iterator it = path.begin(), 
       et = path.end(); it != et; ++it) {
    ID.Add(**it);
  }
}

void PathDiagnosticSpotPiece::Profile(llvm::FoldingSetNodeID &ID) const {
  PathDiagnosticPiece::Profile(ID);
  ID.Add(Pos);
}

void PathDiagnosticControlFlowPiece::Profile(llvm::FoldingSetNodeID &ID) const {
  PathDiagnosticPiece::Profile(ID);
  for (const_iterator I = begin(), E = end(); I != E; ++I)
    ID.Add(*I);
}

void PathDiagnosticMacroPiece::Profile(llvm::FoldingSetNodeID &ID) const {
  PathDiagnosticSpotPiece::Profile(ID);
  for (PathPieces::const_iterator I = subPieces.begin(), E = subPieces.end();
       I != E; ++I)
    ID.Add(**I);
}

void PathDiagnostic::Profile(llvm::FoldingSetNodeID &ID) const {
  if (!path.empty())
    getLocation().Profile(ID);
  ID.AddString(BugType);
  ID.AddString(Desc);
  ID.AddString(Category);
}

void PathDiagnostic::FullProfile(llvm::FoldingSetNodeID &ID) const {
  Profile(ID);
  for (PathPieces::const_iterator I = path.begin(), E = path.end(); I != E; ++I)
    ID.Add(**I);
  for (meta_iterator I = meta_begin(), E = meta_end(); I != E; ++I)
    ID.AddString(*I);
}

StackHintGenerator::~StackHintGenerator() {}

std::string StackHintGeneratorForSymbol::getMessage(const ExplodedNode *N){
  ProgramPoint P = N->getLocation();
  const CallExit *CExit = dyn_cast<CallExit>(&P);
  assert(CExit && "Stack Hints should be constructed at CallExit points.");

  const CallExpr *CE = dyn_cast_or_null<CallExpr>(CExit->getStmt());
  if (!CE)
    return "";

  // Get the successor node to make sure the return statement is evaluated and
  // CE is set to the result value.
  N = *N->succ_begin();
  if (!N)
    return getMessageForSymbolNotFound();

  // Check if one of the parameters are set to the interesting symbol.
  ProgramStateRef State = N->getState();
  const LocationContext *LCtx = N->getLocationContext();
  unsigned ArgIndex = 0;
  for (CallExpr::const_arg_iterator I = CE->arg_begin(),
                                    E = CE->arg_end(); I != E; ++I, ++ArgIndex){
    SVal SV = State->getSVal(*I, LCtx);

    // Check if the variable corresponding to the symbol is passed by value.
    SymbolRef AS = SV.getAsLocSymbol();
    if (AS == Sym) {
      return getMessageForArg(*I, ArgIndex);
    }

    // Check if the parameter is a pointer to the symbol.
    if (const loc::MemRegionVal *Reg = dyn_cast<loc::MemRegionVal>(&SV)) {
      SVal PSV = State->getSVal(Reg->getRegion());
      SymbolRef AS = PSV.getAsLocSymbol();
      if (AS == Sym) {
        return getMessageForArg(*I, ArgIndex);
      }
    }
  }

  // Check if we are returning the interesting symbol.
  SVal SV = State->getSVal(CE, LCtx);
  SymbolRef RetSym = SV.getAsLocSymbol();
  if (RetSym == Sym) {
    return getMessageForReturn(CE);
  }

  return getMessageForSymbolNotFound();
}

/// TODO: This is copied from clang diagnostics. Maybe we could just move it to
/// some common place. (Same as HandleOrdinalModifier.)
void StackHintGeneratorForSymbol::printOrdinal(unsigned ValNo,
                                               llvm::raw_svector_ostream &Out) {
  assert(ValNo != 0 && "ValNo must be strictly positive!");

  // We could use text forms for the first N ordinals, but the numeric
  // forms are actually nicer in diagnostics because they stand out.
  Out << ValNo;

  // It is critically important that we do this perfectly for
  // user-written sequences with over 100 elements.
  switch (ValNo % 100) {
  case 11:
  case 12:
  case 13:
    Out << "th"; return;
  default:
    switch (ValNo % 10) {
    case 1: Out << "st"; return;
    case 2: Out << "nd"; return;
    case 3: Out << "rd"; return;
    default: Out << "th"; return;
    }
  }
}

std::string StackHintGeneratorForSymbol::getMessageForArg(const Expr *ArgE,
                                                        unsigned ArgIndex) {
  SmallString<200> buf;
  llvm::raw_svector_ostream os(buf);

  os << Msg << " via ";
  // Printed parameters start at 1, not 0.
  printOrdinal(++ArgIndex, os);
  os << " parameter";

  return os.str();
}