BugReporter.cpp revision a705980a7c3315b7c72d99ce675342ad91b50642 
1// BugReporter.cpp - Generate PathDiagnostics for Bugs ------------*- C++ -*--//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines BugReporter, a utility class for generating
11//  PathDiagnostics.
12//
13//===----------------------------------------------------------------------===//
14
15#define DEBUG_TYPE "BugReporter"
16
17#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/ParentMap.h"
22#include "clang/AST/StmtObjC.h"
23#include "clang/Analysis/CFG.h"
24#include "clang/Analysis/ProgramPoint.h"
25#include "clang/Basic/SourceManager.h"
26#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
27#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
28#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
29#include "llvm/ADT/DenseMap.h"
30#include "llvm/ADT/IntrusiveRefCntPtr.h"
31#include "llvm/ADT/OwningPtr.h"
32#include "llvm/ADT/STLExtras.h"
33#include "llvm/ADT/SmallString.h"
34#include "llvm/ADT/Statistic.h"
35#include "llvm/Support/raw_ostream.h"
36#include <queue>
37
38using namespace clang;
39using namespace ento;
40
41STATISTIC(MaxBugClassSize,
42          "The maximum number of bug reports in the same equivalence class");
43STATISTIC(MaxValidBugClassSize,
44          "The maximum number of bug reports in the same equivalence class "
45          "where at least one report is valid (not suppressed)");
46
47BugReporterVisitor::~BugReporterVisitor() {}
48
49void BugReporterContext::anchor() {}
50
51//===----------------------------------------------------------------------===//
52// Helper routines for walking the ExplodedGraph and fetching statements.
53//===----------------------------------------------------------------------===//
54
55static const Stmt *GetPreviousStmt(const ExplodedNode *N) {
56  for (N = N->getFirstPred(); N; N = N->getFirstPred())
57    if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
58      return S;
59
60  return 0;
61}
62
63static inline const Stmt*
64GetCurrentOrPreviousStmt(const ExplodedNode *N) {
65  if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
66    return S;
67
68  return GetPreviousStmt(N);
69}
70
71//===----------------------------------------------------------------------===//
72// Diagnostic cleanup.
73//===----------------------------------------------------------------------===//
74
75static PathDiagnosticEventPiece *
76eventsDescribeSameCondition(PathDiagnosticEventPiece *X,
77                            PathDiagnosticEventPiece *Y) {
78  // Prefer diagnostics that come from ConditionBRVisitor over
79  // those that came from TrackConstraintBRVisitor.
80  const void *tagPreferred = ConditionBRVisitor::getTag();
81  const void *tagLesser = TrackConstraintBRVisitor::getTag();
82
83  if (X->getLocation() != Y->getLocation())
84    return 0;
85
86  if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
87    return X;
88
89  if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
90    return Y;
91
92  return 0;
93}
94
95/// An optimization pass over PathPieces that removes redundant diagnostics
96/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor.  Both
97/// BugReporterVisitors use different methods to generate diagnostics, with
98/// one capable of emitting diagnostics in some cases but not in others.  This
99/// can lead to redundant diagnostic pieces at the same point in a path.
100static void removeRedundantMsgs(PathPieces &path) {
101  unsigned N = path.size();
102  if (N < 2)
103    return;
104  // NOTE: this loop intentionally is not using an iterator.  Instead, we
105  // are streaming the path and modifying it in place.  This is done by
106  // grabbing the front, processing it, and if we decide to keep it append
107  // it to the end of the path.  The entire path is processed in this way.
108  for (unsigned i = 0; i < N; ++i) {
109    IntrusiveRefCntPtr<PathDiagnosticPiece> piece(path.front());
110    path.pop_front();
111
112    switch (piece->getKind()) {
113      case clang::ento::PathDiagnosticPiece::Call:
114        removeRedundantMsgs(cast<PathDiagnosticCallPiece>(piece)->path);
115        break;
116      case clang::ento::PathDiagnosticPiece::Macro:
117        removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(piece)->subPieces);
118        break;
119      case clang::ento::PathDiagnosticPiece::ControlFlow:
120        break;
121      case clang::ento::PathDiagnosticPiece::Event: {
122        if (i == N-1)
123          break;
124
125        if (PathDiagnosticEventPiece *nextEvent =
126            dyn_cast<PathDiagnosticEventPiece>(path.front().getPtr())) {
127          PathDiagnosticEventPiece *event =
128            cast<PathDiagnosticEventPiece>(piece);
129          // Check to see if we should keep one of the two pieces.  If we
130          // come up with a preference, record which piece to keep, and consume
131          // another piece from the path.
132          if (PathDiagnosticEventPiece *pieceToKeep =
133              eventsDescribeSameCondition(event, nextEvent)) {
134            piece = pieceToKeep;
135            path.pop_front();
136            ++i;
137          }
138        }
139        break;
140      }
141    }
142    path.push_back(piece);
143  }
144}
145
146/// A map from PathDiagnosticPiece to the LocationContext of the inlined
147/// function call it represents.
148typedef llvm::DenseMap<const PathPieces *, const LocationContext *>
149        LocationContextMap;
150
151/// Recursively scan through a path and prune out calls and macros pieces
152/// that aren't needed.  Return true if afterwards the path contains
153/// "interesting stuff" which means it shouldn't be pruned from the parent path.
154static bool removeUnneededCalls(PathPieces &pieces, BugReport *R,
155                                LocationContextMap &LCM) {
156  bool containsSomethingInteresting = false;
157  const unsigned N = pieces.size();
158
159  for (unsigned i = 0 ; i < N ; ++i) {
160    // Remove the front piece from the path.  If it is still something we
161    // want to keep once we are done, we will push it back on the end.
162    IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front());
163    pieces.pop_front();
164
165    // Throw away pieces with invalid locations. Note that we can't throw away
166    // calls just yet because they might have something interesting inside them.
167    // If so, their locations will be adjusted as necessary later.
168    if (piece->getKind() != PathDiagnosticPiece::Call &&
169        piece->getLocation().asLocation().isInvalid())
170      continue;
171
172    switch (piece->getKind()) {
173      case PathDiagnosticPiece::Call: {
174        PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece);
175        // Check if the location context is interesting.
176        assert(LCM.count(&call->path));
177        if (R->isInteresting(LCM[&call->path])) {
178          containsSomethingInteresting = true;
179          break;
180        }
181
182        if (!removeUnneededCalls(call->path, R, LCM))
183          continue;
184
185        containsSomethingInteresting = true;
186        break;
187      }
188      case PathDiagnosticPiece::Macro: {
189        PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece);
190        if (!removeUnneededCalls(macro->subPieces, R, LCM))
191          continue;
192        containsSomethingInteresting = true;
193        break;
194      }
195      case PathDiagnosticPiece::Event: {
196        PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece);
197
198        // We never throw away an event, but we do throw it away wholesale
199        // as part of a path if we throw the entire path away.
200        containsSomethingInteresting |= !event->isPrunable();
201        break;
202      }
203      case PathDiagnosticPiece::ControlFlow:
204        break;
205    }
206
207    pieces.push_back(piece);
208  }
209
210  return containsSomethingInteresting;
211}
212
213/// Recursively scan through a path and make sure that all call pieces have
214/// valid locations. Note that all other pieces with invalid locations should
215/// have already been pruned out.
216static void adjustCallLocations(PathPieces &Pieces,
217                                PathDiagnosticLocation *LastCallLocation = 0) {
218  for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E; ++I) {
219    PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I);
220
221    if (!Call) {
222      assert((*I)->getLocation().asLocation().isValid());
223      continue;
224    }
225
226    if (LastCallLocation) {
227      if (!Call->callEnter.asLocation().isValid() ||
228          Call->getCaller()->isImplicit())
229        Call->callEnter = *LastCallLocation;
230      if (!Call->callReturn.asLocation().isValid() ||
231          Call->getCaller()->isImplicit())
232        Call->callReturn = *LastCallLocation;
233    }
234
235    // Recursively clean out the subclass.  Keep this call around if
236    // it contains any informative diagnostics.
237    PathDiagnosticLocation *ThisCallLocation;
238    if (Call->callEnterWithin.asLocation().isValid() &&
239        !Call->getCallee()->isImplicit())
240      ThisCallLocation = &Call->callEnterWithin;
241    else
242      ThisCallLocation = &Call->callEnter;
243
244    assert(ThisCallLocation && "Outermost call has an invalid location");
245    adjustCallLocations(Call->path, ThisCallLocation);
246  }
247}
248
249//===----------------------------------------------------------------------===//
250// PathDiagnosticBuilder and its associated routines and helper objects.
251//===----------------------------------------------------------------------===//
252
253namespace {
254class NodeMapClosure : public BugReport::NodeResolver {
255  InterExplodedGraphMap &M;
256public:
257  NodeMapClosure(InterExplodedGraphMap &m) : M(m) {}
258
259  const ExplodedNode *getOriginalNode(const ExplodedNode *N) {
260    return M.lookup(N);
261  }
262};
263
264class PathDiagnosticBuilder : public BugReporterContext {
265  BugReport *R;
266  PathDiagnosticConsumer *PDC;
267  NodeMapClosure NMC;
268public:
269  const LocationContext *LC;
270
271  PathDiagnosticBuilder(GRBugReporter &br,
272                        BugReport *r, InterExplodedGraphMap &Backmap,
273                        PathDiagnosticConsumer *pdc)
274    : BugReporterContext(br),
275      R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext())
276  {}
277
278  PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N);
279
280  PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os,
281                                            const ExplodedNode *N);
282
283  BugReport *getBugReport() { return R; }
284
285  Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); }
286
287  ParentMap& getParentMap() { return LC->getParentMap(); }
288
289  const Stmt *getParent(const Stmt *S) {
290    return getParentMap().getParent(S);
291  }
292
293  virtual NodeMapClosure& getNodeResolver() { return NMC; }
294
295  PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S);
296
297  PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const {
298    return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive;
299  }
300
301  bool supportsLogicalOpControlFlow() const {
302    return PDC ? PDC->supportsLogicalOpControlFlow() : true;
303  }
304};
305} // end anonymous namespace
306
307PathDiagnosticLocation
308PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) {
309  if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N))
310    return PathDiagnosticLocation(S, getSourceManager(), LC);
311
312  return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(),
313                                               getSourceManager());
314}
315
316PathDiagnosticLocation
317PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os,
318                                          const ExplodedNode *N) {
319
320  // Slow, but probably doesn't matter.
321  if (os.str().empty())
322    os << ' ';
323
324  const PathDiagnosticLocation &Loc = ExecutionContinues(N);
325
326  if (Loc.asStmt())
327    os << "Execution continues on line "
328       << getSourceManager().getExpansionLineNumber(Loc.asLocation())
329       << '.';
330  else {
331    os << "Execution jumps to the end of the ";
332    const Decl *D = N->getLocationContext()->getDecl();
333    if (isa<ObjCMethodDecl>(D))
334      os << "method";
335    else if (isa<FunctionDecl>(D))
336      os << "function";
337    else {
338      assert(isa<BlockDecl>(D));
339      os << "anonymous block";
340    }
341    os << '.';
342  }
343
344  return Loc;
345}
346
347static bool IsNested(const Stmt *S, ParentMap &PM) {
348  if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S)))
349    return true;
350
351  const Stmt *Parent = PM.getParentIgnoreParens(S);
352
353  if (Parent)
354    switch (Parent->getStmtClass()) {
355      case Stmt::ForStmtClass:
356      case Stmt::DoStmtClass:
357      case Stmt::WhileStmtClass:
358        return true;
359      default:
360        break;
361    }
362
363  return false;
364}
365
366PathDiagnosticLocation
367PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) {
368  assert(S && "Null Stmt *passed to getEnclosingStmtLocation");
369  ParentMap &P = getParentMap();
370  SourceManager &SMgr = getSourceManager();
371
372  while (IsNested(S, P)) {
373    const Stmt *Parent = P.getParentIgnoreParens(S);
374
375    if (!Parent)
376      break;
377
378    switch (Parent->getStmtClass()) {
379      case Stmt::BinaryOperatorClass: {
380        const BinaryOperator *B = cast<BinaryOperator>(Parent);
381        if (B->isLogicalOp())
382          return PathDiagnosticLocation(S, SMgr, LC);
383        break;
384      }
385      case Stmt::CompoundStmtClass:
386      case Stmt::StmtExprClass:
387        return PathDiagnosticLocation(S, SMgr, LC);
388      case Stmt::ChooseExprClass:
389        // Similar to '?' if we are referring to condition, just have the edge
390        // point to the entire choose expression.
391        if (cast<ChooseExpr>(Parent)->getCond() == S)
392          return PathDiagnosticLocation(Parent, SMgr, LC);
393        else
394          return PathDiagnosticLocation(S, SMgr, LC);
395      case Stmt::BinaryConditionalOperatorClass:
396      case Stmt::ConditionalOperatorClass:
397        // For '?', if we are referring to condition, just have the edge point
398        // to the entire '?' expression.
399        if (cast<AbstractConditionalOperator>(Parent)->getCond() == S)
400          return PathDiagnosticLocation(Parent, SMgr, LC);
401        else
402          return PathDiagnosticLocation(S, SMgr, LC);
403      case Stmt::DoStmtClass:
404          return PathDiagnosticLocation(S, SMgr, LC);
405      case Stmt::ForStmtClass:
406        if (cast<ForStmt>(Parent)->getBody() == S)
407          return PathDiagnosticLocation(S, SMgr, LC);
408        break;
409      case Stmt::IfStmtClass:
410        if (cast<IfStmt>(Parent)->getCond() != S)
411          return PathDiagnosticLocation(S, SMgr, LC);
412        break;
413      case Stmt::ObjCForCollectionStmtClass:
414        if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S)
415          return PathDiagnosticLocation(S, SMgr, LC);
416        break;
417      case Stmt::WhileStmtClass:
418        if (cast<WhileStmt>(Parent)->getCond() != S)
419          return PathDiagnosticLocation(S, SMgr, LC);
420        break;
421      default:
422        break;
423    }
424
425    S = Parent;
426  }
427
428  assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
429
430  // Special case: DeclStmts can appear in for statement declarations, in which
431  //  case the ForStmt is the context.
432  if (isa<DeclStmt>(S)) {
433    if (const Stmt *Parent = P.getParent(S)) {
434      switch (Parent->getStmtClass()) {
435        case Stmt::ForStmtClass:
436        case Stmt::ObjCForCollectionStmtClass:
437          return PathDiagnosticLocation(Parent, SMgr, LC);
438        default:
439          break;
440      }
441    }
442  }
443  else if (isa<BinaryOperator>(S)) {
444    // Special case: the binary operator represents the initialization
445    // code in a for statement (this can happen when the variable being
446    // initialized is an old variable.
447    if (const ForStmt *FS =
448          dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) {
449      if (FS->getInit() == S)
450        return PathDiagnosticLocation(FS, SMgr, LC);
451    }
452  }
453
454  return PathDiagnosticLocation(S, SMgr, LC);
455}
456
457//===----------------------------------------------------------------------===//
458// "Visitors only" path diagnostic generation algorithm.
459//===----------------------------------------------------------------------===//
460static bool GenerateVisitorsOnlyPathDiagnostic(PathDiagnostic &PD,
461                                               PathDiagnosticBuilder &PDB,
462                                               const ExplodedNode *N,
463                                      ArrayRef<BugReporterVisitor *> visitors) {
464  // All path generation skips the very first node (the error node).
465  // This is because there is special handling for the end-of-path note.
466  N = N->getFirstPred();
467  if (!N)
468    return true;
469
470  BugReport *R = PDB.getBugReport();
471  while (const ExplodedNode *Pred = N->getFirstPred()) {
472    for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(),
473                                                  E = visitors.end();
474         I != E; ++I) {
475      // Visit all the node pairs, but throw the path pieces away.
476      PathDiagnosticPiece *Piece = (*I)->VisitNode(N, Pred, PDB, *R);
477      delete Piece;
478    }
479
480    N = Pred;
481  }
482
483  return R->isValid();
484}
485
486//===----------------------------------------------------------------------===//
487// "Minimal" path diagnostic generation algorithm.
488//===----------------------------------------------------------------------===//
489typedef std::pair<PathDiagnosticCallPiece*, const ExplodedNode*> StackDiagPair;
490typedef SmallVector<StackDiagPair, 6> StackDiagVector;
491
492static void updateStackPiecesWithMessage(PathDiagnosticPiece *P,
493                                         StackDiagVector &CallStack) {
494  // If the piece contains a special message, add it to all the call
495  // pieces on the active stack.
496  if (PathDiagnosticEventPiece *ep =
497        dyn_cast<PathDiagnosticEventPiece>(P)) {
498
499    if (ep->hasCallStackHint())
500      for (StackDiagVector::iterator I = CallStack.begin(),
501                                     E = CallStack.end(); I != E; ++I) {
502        PathDiagnosticCallPiece *CP = I->first;
503        const ExplodedNode *N = I->second;
504        std::string stackMsg = ep->getCallStackMessage(N);
505
506        // The last message on the path to final bug is the most important
507        // one. Since we traverse the path backwards, do not add the message
508        // if one has been previously added.
509        if  (!CP->hasCallStackMessage())
510          CP->setCallStackMessage(stackMsg);
511      }
512  }
513}
514
515static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM);
516
517static bool GenerateMinimalPathDiagnostic(PathDiagnostic& PD,
518                                          PathDiagnosticBuilder &PDB,
519                                          const ExplodedNode *N,
520                                          LocationContextMap &LCM,
521                                      ArrayRef<BugReporterVisitor *> visitors) {
522
523  SourceManager& SMgr = PDB.getSourceManager();
524  const LocationContext *LC = PDB.LC;
525  const ExplodedNode *NextNode = N->pred_empty()
526                                        ? NULL : *(N->pred_begin());
527
528  StackDiagVector CallStack;
529
530  while (NextNode) {
531    N = NextNode;
532    PDB.LC = N->getLocationContext();
533    NextNode = N->getFirstPred();
534
535    ProgramPoint P = N->getLocation();
536
537    do {
538      if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
539        PathDiagnosticCallPiece *C =
540            PathDiagnosticCallPiece::construct(N, *CE, SMgr);
541        // Record the mapping from call piece to LocationContext.
542        LCM[&C->path] = CE->getCalleeContext();
543        PD.getActivePath().push_front(C);
544        PD.pushActivePath(&C->path);
545        CallStack.push_back(StackDiagPair(C, N));
546        break;
547      }
548
549      if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
550        // Flush all locations, and pop the active path.
551        bool VisitedEntireCall = PD.isWithinCall();
552        PD.popActivePath();
553
554        // Either we just added a bunch of stuff to the top-level path, or
555        // we have a previous CallExitEnd.  If the former, it means that the
556        // path terminated within a function call.  We must then take the
557        // current contents of the active path and place it within
558        // a new PathDiagnosticCallPiece.
559        PathDiagnosticCallPiece *C;
560        if (VisitedEntireCall) {
561          C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
562        } else {
563          const Decl *Caller = CE->getLocationContext()->getDecl();
564          C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
565          // Record the mapping from call piece to LocationContext.
566          LCM[&C->path] = CE->getCalleeContext();
567        }
568
569        C->setCallee(*CE, SMgr);
570        if (!CallStack.empty()) {
571          assert(CallStack.back().first == C);
572          CallStack.pop_back();
573        }
574        break;
575      }
576
577      if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
578        const CFGBlock *Src = BE->getSrc();
579        const CFGBlock *Dst = BE->getDst();
580        const Stmt *T = Src->getTerminator();
581
582        if (!T)
583          break;
584
585        PathDiagnosticLocation Start =
586            PathDiagnosticLocation::createBegin(T, SMgr,
587                N->getLocationContext());
588
589        switch (T->getStmtClass()) {
590        default:
591          break;
592
593        case Stmt::GotoStmtClass:
594        case Stmt::IndirectGotoStmtClass: {
595          const Stmt *S = PathDiagnosticLocation::getNextStmt(N);
596
597          if (!S)
598            break;
599
600          std::string sbuf;
601          llvm::raw_string_ostream os(sbuf);
602          const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S);
603
604          os << "Control jumps to line "
605              << End.asLocation().getExpansionLineNumber();
606          PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
607              Start, End, os.str()));
608          break;
609        }
610
611        case Stmt::SwitchStmtClass: {
612          // Figure out what case arm we took.
613          std::string sbuf;
614          llvm::raw_string_ostream os(sbuf);
615
616          if (const Stmt *S = Dst->getLabel()) {
617            PathDiagnosticLocation End(S, SMgr, LC);
618
619            switch (S->getStmtClass()) {
620            default:
621              os << "No cases match in the switch statement. "
622              "Control jumps to line "
623              << End.asLocation().getExpansionLineNumber();
624              break;
625            case Stmt::DefaultStmtClass:
626              os << "Control jumps to the 'default' case at line "
627              << End.asLocation().getExpansionLineNumber();
628              break;
629
630            case Stmt::CaseStmtClass: {
631              os << "Control jumps to 'case ";
632              const CaseStmt *Case = cast<CaseStmt>(S);
633              const Expr *LHS = Case->getLHS()->IgnoreParenCasts();
634
635              // Determine if it is an enum.
636              bool GetRawInt = true;
637
638              if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) {
639                // FIXME: Maybe this should be an assertion.  Are there cases
640                // were it is not an EnumConstantDecl?
641                const EnumConstantDecl *D =
642                    dyn_cast<EnumConstantDecl>(DR->getDecl());
643
644                if (D) {
645                  GetRawInt = false;
646                  os << *D;
647                }
648              }
649
650              if (GetRawInt)
651                os << LHS->EvaluateKnownConstInt(PDB.getASTContext());
652
653              os << ":'  at line "
654                  << End.asLocation().getExpansionLineNumber();
655              break;
656            }
657            }
658            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
659                Start, End, os.str()));
660          }
661          else {
662            os << "'Default' branch taken. ";
663            const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N);
664            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
665                Start, End, os.str()));
666          }
667
668          break;
669        }
670
671        case Stmt::BreakStmtClass:
672        case Stmt::ContinueStmtClass: {
673          std::string sbuf;
674          llvm::raw_string_ostream os(sbuf);
675          PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
676          PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
677              Start, End, os.str()));
678          break;
679        }
680
681        // Determine control-flow for ternary '?'.
682        case Stmt::BinaryConditionalOperatorClass:
683        case Stmt::ConditionalOperatorClass: {
684          std::string sbuf;
685          llvm::raw_string_ostream os(sbuf);
686          os << "'?' condition is ";
687
688          if (*(Src->succ_begin()+1) == Dst)
689            os << "false";
690          else
691            os << "true";
692
693          PathDiagnosticLocation End = PDB.ExecutionContinues(N);
694
695          if (const Stmt *S = End.asStmt())
696            End = PDB.getEnclosingStmtLocation(S);
697
698          PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
699              Start, End, os.str()));
700          break;
701        }
702
703        // Determine control-flow for short-circuited '&&' and '||'.
704        case Stmt::BinaryOperatorClass: {
705          if (!PDB.supportsLogicalOpControlFlow())
706            break;
707
708          const BinaryOperator *B = cast<BinaryOperator>(T);
709          std::string sbuf;
710          llvm::raw_string_ostream os(sbuf);
711          os << "Left side of '";
712
713          if (B->getOpcode() == BO_LAnd) {
714            os << "&&" << "' is ";
715
716            if (*(Src->succ_begin()+1) == Dst) {
717              os << "false";
718              PathDiagnosticLocation End(B->getLHS(), SMgr, LC);
719              PathDiagnosticLocation Start =
720                  PathDiagnosticLocation::createOperatorLoc(B, SMgr);
721              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
722                  Start, End, os.str()));
723            }
724            else {
725              os << "true";
726              PathDiagnosticLocation Start(B->getLHS(), SMgr, LC);
727              PathDiagnosticLocation End = PDB.ExecutionContinues(N);
728              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
729                  Start, End, os.str()));
730            }
731          }
732          else {
733            assert(B->getOpcode() == BO_LOr);
734            os << "||" << "' is ";
735
736            if (*(Src->succ_begin()+1) == Dst) {
737              os << "false";
738              PathDiagnosticLocation Start(B->getLHS(), SMgr, LC);
739              PathDiagnosticLocation End = PDB.ExecutionContinues(N);
740              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
741                  Start, End, os.str()));
742            }
743            else {
744              os << "true";
745              PathDiagnosticLocation End(B->getLHS(), SMgr, LC);
746              PathDiagnosticLocation Start =
747                  PathDiagnosticLocation::createOperatorLoc(B, SMgr);
748              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
749                  Start, End, os.str()));
750            }
751          }
752
753          break;
754        }
755
756        case Stmt::DoStmtClass:  {
757          if (*(Src->succ_begin()) == Dst) {
758            std::string sbuf;
759            llvm::raw_string_ostream os(sbuf);
760
761            os << "Loop condition is true. ";
762            PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
763
764            if (const Stmt *S = End.asStmt())
765              End = PDB.getEnclosingStmtLocation(S);
766
767            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
768                Start, End, os.str()));
769          }
770          else {
771            PathDiagnosticLocation End = PDB.ExecutionContinues(N);
772
773            if (const Stmt *S = End.asStmt())
774              End = PDB.getEnclosingStmtLocation(S);
775
776            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
777                Start, End, "Loop condition is false.  Exiting loop"));
778          }
779
780          break;
781        }
782
783        case Stmt::WhileStmtClass:
784        case Stmt::ForStmtClass: {
785          if (*(Src->succ_begin()+1) == Dst) {
786            std::string sbuf;
787            llvm::raw_string_ostream os(sbuf);
788
789            os << "Loop condition is false. ";
790            PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
791            if (const Stmt *S = End.asStmt())
792              End = PDB.getEnclosingStmtLocation(S);
793
794            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
795                Start, End, os.str()));
796          }
797          else {
798            PathDiagnosticLocation End = PDB.ExecutionContinues(N);
799            if (const Stmt *S = End.asStmt())
800              End = PDB.getEnclosingStmtLocation(S);
801
802            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
803                Start, End, "Loop condition is true.  Entering loop body"));
804          }
805
806          break;
807        }
808
809        case Stmt::IfStmtClass: {
810          PathDiagnosticLocation End = PDB.ExecutionContinues(N);
811
812          if (const Stmt *S = End.asStmt())
813            End = PDB.getEnclosingStmtLocation(S);
814
815          if (*(Src->succ_begin()+1) == Dst)
816            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
817                Start, End, "Taking false branch"));
818          else
819            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(
820                Start, End, "Taking true branch"));
821
822          break;
823        }
824        }
825      }
826    } while(0);
827
828    if (NextNode) {
829      // Add diagnostic pieces from custom visitors.
830      BugReport *R = PDB.getBugReport();
831      for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(),
832                                                    E = visitors.end();
833           I != E; ++I) {
834        if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) {
835          PD.getActivePath().push_front(p);
836          updateStackPiecesWithMessage(p, CallStack);
837        }
838      }
839    }
840  }
841
842  if (!PDB.getBugReport()->isValid())
843    return false;
844
845  // After constructing the full PathDiagnostic, do a pass over it to compact
846  // PathDiagnosticPieces that occur within a macro.
847  CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager());
848  return true;
849}
850
851//===----------------------------------------------------------------------===//
852// "Extensive" PathDiagnostic generation.
853//===----------------------------------------------------------------------===//
854
855static bool IsControlFlowExpr(const Stmt *S) {
856  const Expr *E = dyn_cast<Expr>(S);
857
858  if (!E)
859    return false;
860
861  E = E->IgnoreParenCasts();
862
863  if (isa<AbstractConditionalOperator>(E))
864    return true;
865
866  if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E))
867    if (B->isLogicalOp())
868      return true;
869
870  return false;
871}
872
873namespace {
874class ContextLocation : public PathDiagnosticLocation {
875  bool IsDead;
876public:
877  ContextLocation(const PathDiagnosticLocation &L, bool isdead = false)
878    : PathDiagnosticLocation(L), IsDead(isdead) {}
879
880  void markDead() { IsDead = true; }
881  bool isDead() const { return IsDead; }
882};
883
884static PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L,
885                                              const LocationContext *LC,
886                                              bool firstCharOnly = false) {
887  if (const Stmt *S = L.asStmt()) {
888    const Stmt *Original = S;
889    while (1) {
890      // Adjust the location for some expressions that are best referenced
891      // by one of their subexpressions.
892      switch (S->getStmtClass()) {
893        default:
894          break;
895        case Stmt::ParenExprClass:
896        case Stmt::GenericSelectionExprClass:
897          S = cast<Expr>(S)->IgnoreParens();
898          firstCharOnly = true;
899          continue;
900        case Stmt::BinaryConditionalOperatorClass:
901        case Stmt::ConditionalOperatorClass:
902          S = cast<AbstractConditionalOperator>(S)->getCond();
903          firstCharOnly = true;
904          continue;
905        case Stmt::ChooseExprClass:
906          S = cast<ChooseExpr>(S)->getCond();
907          firstCharOnly = true;
908          continue;
909        case Stmt::BinaryOperatorClass:
910          S = cast<BinaryOperator>(S)->getLHS();
911          firstCharOnly = true;
912          continue;
913      }
914
915      break;
916    }
917
918    if (S != Original)
919      L = PathDiagnosticLocation(S, L.getManager(), LC);
920  }
921
922  if (firstCharOnly)
923    L  = PathDiagnosticLocation::createSingleLocation(L);
924
925  return L;
926}
927
928class EdgeBuilder {
929  std::vector<ContextLocation> CLocs;
930  typedef std::vector<ContextLocation>::iterator iterator;
931  PathDiagnostic &PD;
932  PathDiagnosticBuilder &PDB;
933  PathDiagnosticLocation PrevLoc;
934
935  bool IsConsumedExpr(const PathDiagnosticLocation &L);
936
937  bool containsLocation(const PathDiagnosticLocation &Container,
938                        const PathDiagnosticLocation &Containee);
939
940  PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L);
941
942
943
944  void popLocation() {
945    if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) {
946      // For contexts, we only one the first character as the range.
947      rawAddEdge(cleanUpLocation(CLocs.back(), PDB.LC, true));
948    }
949    CLocs.pop_back();
950  }
951
952public:
953  EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb)
954    : PD(pd), PDB(pdb) {
955
956      // If the PathDiagnostic already has pieces, add the enclosing statement
957      // of the first piece as a context as well.
958      if (!PD.path.empty()) {
959        PrevLoc = (*PD.path.begin())->getLocation();
960
961        if (const Stmt *S = PrevLoc.asStmt())
962          addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt());
963      }
964  }
965
966  ~EdgeBuilder() {
967    while (!CLocs.empty()) popLocation();
968
969    // Finally, add an initial edge from the start location of the first
970    // statement (if it doesn't already exist).
971    PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin(
972                                                       PDB.LC,
973                                                       PDB.getSourceManager());
974    if (L.isValid())
975      rawAddEdge(L);
976  }
977
978  void flushLocations() {
979    while (!CLocs.empty())
980      popLocation();
981    PrevLoc = PathDiagnosticLocation();
982  }
983
984  void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false,
985               bool IsPostJump = false);
986
987  void rawAddEdge(PathDiagnosticLocation NewLoc);
988
989  void addContext(const Stmt *S);
990  void addContext(const PathDiagnosticLocation &L);
991  void addExtendedContext(const Stmt *S);
992};
993} // end anonymous namespace
994
995
996PathDiagnosticLocation
997EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) {
998  if (const Stmt *S = L.asStmt()) {
999    if (IsControlFlowExpr(S))
1000      return L;
1001
1002    return PDB.getEnclosingStmtLocation(S);
1003  }
1004
1005  return L;
1006}
1007
1008bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container,
1009                                   const PathDiagnosticLocation &Containee) {
1010
1011  if (Container == Containee)
1012    return true;
1013
1014  if (Container.asDecl())
1015    return true;
1016
1017  if (const Stmt *S = Containee.asStmt())
1018    if (const Stmt *ContainerS = Container.asStmt()) {
1019      while (S) {
1020        if (S == ContainerS)
1021          return true;
1022        S = PDB.getParent(S);
1023      }
1024      return false;
1025    }
1026
1027  // Less accurate: compare using source ranges.
1028  SourceRange ContainerR = Container.asRange();
1029  SourceRange ContaineeR = Containee.asRange();
1030
1031  SourceManager &SM = PDB.getSourceManager();
1032  SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin());
1033  SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd());
1034  SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin());
1035  SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd());
1036
1037  unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg);
1038  unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd);
1039  unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg);
1040  unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd);
1041
1042  assert(ContainerBegLine <= ContainerEndLine);
1043  assert(ContaineeBegLine <= ContaineeEndLine);
1044
1045  return (ContainerBegLine <= ContaineeBegLine &&
1046          ContainerEndLine >= ContaineeEndLine &&
1047          (ContainerBegLine != ContaineeBegLine ||
1048           SM.getExpansionColumnNumber(ContainerRBeg) <=
1049           SM.getExpansionColumnNumber(ContaineeRBeg)) &&
1050          (ContainerEndLine != ContaineeEndLine ||
1051           SM.getExpansionColumnNumber(ContainerREnd) >=
1052           SM.getExpansionColumnNumber(ContaineeREnd)));
1053}
1054
1055void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) {
1056  if (!PrevLoc.isValid()) {
1057    PrevLoc = NewLoc;
1058    return;
1059  }
1060
1061  const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc, PDB.LC);
1062  const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc, PDB.LC);
1063
1064  if (PrevLocClean.asLocation().isInvalid()) {
1065    PrevLoc = NewLoc;
1066    return;
1067  }
1068
1069  if (NewLocClean.asLocation() == PrevLocClean.asLocation())
1070    return;
1071
1072  // FIXME: Ignore intra-macro edges for now.
1073  if (NewLocClean.asLocation().getExpansionLoc() ==
1074      PrevLocClean.asLocation().getExpansionLoc())
1075    return;
1076
1077  PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean));
1078  PrevLoc = NewLoc;
1079}
1080
1081void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd,
1082                          bool IsPostJump) {
1083
1084  if (!alwaysAdd && NewLoc.asLocation().isMacroID())
1085    return;
1086
1087  const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc);
1088
1089  while (!CLocs.empty()) {
1090    ContextLocation &TopContextLoc = CLocs.back();
1091
1092    // Is the top location context the same as the one for the new location?
1093    if (TopContextLoc == CLoc) {
1094      if (alwaysAdd) {
1095        if (IsConsumedExpr(TopContextLoc))
1096          TopContextLoc.markDead();
1097
1098        rawAddEdge(NewLoc);
1099      }
1100
1101      if (IsPostJump)
1102        TopContextLoc.markDead();
1103      return;
1104    }
1105
1106    if (containsLocation(TopContextLoc, CLoc)) {
1107      if (alwaysAdd) {
1108        rawAddEdge(NewLoc);
1109
1110        if (IsConsumedExpr(CLoc)) {
1111          CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/true));
1112          return;
1113        }
1114      }
1115
1116      CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/IsPostJump));
1117      return;
1118    }
1119
1120    // Context does not contain the location.  Flush it.
1121    popLocation();
1122  }
1123
1124  // If we reach here, there is no enclosing context.  Just add the edge.
1125  rawAddEdge(NewLoc);
1126}
1127
1128bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) {
1129  if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt()))
1130    return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X);
1131
1132  return false;
1133}
1134
1135void EdgeBuilder::addExtendedContext(const Stmt *S) {
1136  if (!S)
1137    return;
1138
1139  const Stmt *Parent = PDB.getParent(S);
1140  while (Parent) {
1141    if (isa<CompoundStmt>(Parent))
1142      Parent = PDB.getParent(Parent);
1143    else
1144      break;
1145  }
1146
1147  if (Parent) {
1148    switch (Parent->getStmtClass()) {
1149      case Stmt::DoStmtClass:
1150      case Stmt::ObjCAtSynchronizedStmtClass:
1151        addContext(Parent);
1152      default:
1153        break;
1154    }
1155  }
1156
1157  addContext(S);
1158}
1159
1160void EdgeBuilder::addContext(const Stmt *S) {
1161  if (!S)
1162    return;
1163
1164  PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC);
1165  addContext(L);
1166}
1167
1168void EdgeBuilder::addContext(const PathDiagnosticLocation &L) {
1169  while (!CLocs.empty()) {
1170    const PathDiagnosticLocation &TopContextLoc = CLocs.back();
1171
1172    // Is the top location context the same as the one for the new location?
1173    if (TopContextLoc == L)
1174      return;
1175
1176    if (containsLocation(TopContextLoc, L)) {
1177      CLocs.push_back(L);
1178      return;
1179    }
1180
1181    // Context does not contain the location.  Flush it.
1182    popLocation();
1183  }
1184
1185  CLocs.push_back(L);
1186}
1187
1188// Cone-of-influence: support the reverse propagation of "interesting" symbols
1189// and values by tracing interesting calculations backwards through evaluated
1190// expressions along a path.  This is probably overly complicated, but the idea
1191// is that if an expression computed an "interesting" value, the child
1192// expressions are are also likely to be "interesting" as well (which then
1193// propagates to the values they in turn compute).  This reverse propagation
1194// is needed to track interesting correlations across function call boundaries,
1195// where formal arguments bind to actual arguments, etc.  This is also needed
1196// because the constraint solver sometimes simplifies certain symbolic values
1197// into constants when appropriate, and this complicates reasoning about
1198// interesting values.
1199typedef llvm::DenseSet<const Expr *> InterestingExprs;
1200
1201static void reversePropagateIntererstingSymbols(BugReport &R,
1202                                                InterestingExprs &IE,
1203                                                const ProgramState *State,
1204                                                const Expr *Ex,
1205                                                const LocationContext *LCtx) {
1206  SVal V = State->getSVal(Ex, LCtx);
1207  if (!(R.isInteresting(V) || IE.count(Ex)))
1208    return;
1209
1210  switch (Ex->getStmtClass()) {
1211    default:
1212      if (!isa<CastExpr>(Ex))
1213        break;
1214      // Fall through.
1215    case Stmt::BinaryOperatorClass:
1216    case Stmt::UnaryOperatorClass: {
1217      for (Stmt::const_child_iterator CI = Ex->child_begin(),
1218            CE = Ex->child_end();
1219            CI != CE; ++CI) {
1220        if (const Expr *child = dyn_cast_or_null<Expr>(*CI)) {
1221          IE.insert(child);
1222          SVal ChildV = State->getSVal(child, LCtx);
1223          R.markInteresting(ChildV);
1224        }
1225        break;
1226      }
1227    }
1228  }
1229
1230  R.markInteresting(V);
1231}
1232
1233static void reversePropagateInterestingSymbols(BugReport &R,
1234                                               InterestingExprs &IE,
1235                                               const ProgramState *State,
1236                                               const LocationContext *CalleeCtx,
1237                                               const LocationContext *CallerCtx)
1238{
1239  // FIXME: Handle non-CallExpr-based CallEvents.
1240  const StackFrameContext *Callee = CalleeCtx->getCurrentStackFrame();
1241  const Stmt *CallSite = Callee->getCallSite();
1242  if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(CallSite)) {
1243    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) {
1244      FunctionDecl::param_const_iterator PI = FD->param_begin(),
1245                                         PE = FD->param_end();
1246      CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
1247      for (; AI != AE && PI != PE; ++AI, ++PI) {
1248        if (const Expr *ArgE = *AI) {
1249          if (const ParmVarDecl *PD = *PI) {
1250            Loc LV = State->getLValue(PD, CalleeCtx);
1251            if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV)))
1252              IE.insert(ArgE);
1253          }
1254        }
1255      }
1256    }
1257  }
1258}
1259
1260//===----------------------------------------------------------------------===//
1261// Functions for determining if a loop was executed 0 times.
1262//===----------------------------------------------------------------------===//
1263
1264static bool isLoop(const Stmt *Term) {
1265  switch (Term->getStmtClass()) {
1266    case Stmt::ForStmtClass:
1267    case Stmt::WhileStmtClass:
1268    case Stmt::ObjCForCollectionStmtClass:
1269      return true;
1270    default:
1271      // Note that we intentionally do not include do..while here.
1272      return false;
1273  }
1274}
1275
1276static bool isJumpToFalseBranch(const BlockEdge *BE) {
1277  const CFGBlock *Src = BE->getSrc();
1278  assert(Src->succ_size() == 2);
1279  return (*(Src->succ_begin()+1) == BE->getDst());
1280}
1281
1282/// Return true if the terminator is a loop and the destination is the
1283/// false branch.
1284static bool isLoopJumpPastBody(const Stmt *Term, const BlockEdge *BE) {
1285  if (!isLoop(Term))
1286    return false;
1287
1288  // Did we take the false branch?
1289  return isJumpToFalseBranch(BE);
1290}
1291
1292static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) {
1293  while (SubS) {
1294    if (SubS == S)
1295      return true;
1296    SubS = PM.getParent(SubS);
1297  }
1298  return false;
1299}
1300
1301static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term,
1302                                     const ExplodedNode *N) {
1303  while (N) {
1304    Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>();
1305    if (SP) {
1306      const Stmt *S = SP->getStmt();
1307      if (!isContainedByStmt(PM, Term, S))
1308        return S;
1309    }
1310    N = N->getFirstPred();
1311  }
1312  return 0;
1313}
1314
1315static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) {
1316  const Stmt *LoopBody = 0;
1317  switch (Term->getStmtClass()) {
1318    case Stmt::ForStmtClass: {
1319      const ForStmt *FS = cast<ForStmt>(Term);
1320      if (isContainedByStmt(PM, FS->getInc(), S))
1321        return true;
1322      LoopBody = FS->getBody();
1323      break;
1324    }
1325    case Stmt::ObjCForCollectionStmtClass: {
1326      const ObjCForCollectionStmt *FC = cast<ObjCForCollectionStmt>(Term);
1327      LoopBody = FC->getBody();
1328      break;
1329    }
1330    case Stmt::WhileStmtClass:
1331      LoopBody = cast<WhileStmt>(Term)->getBody();
1332      break;
1333    default:
1334      return false;
1335  }
1336  return isContainedByStmt(PM, LoopBody, S);
1337}
1338
1339//===----------------------------------------------------------------------===//
1340// Top-level logic for generating extensive path diagnostics.
1341//===----------------------------------------------------------------------===//
1342
1343static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD,
1344                                            PathDiagnosticBuilder &PDB,
1345                                            const ExplodedNode *N,
1346                                            LocationContextMap &LCM,
1347                                      ArrayRef<BugReporterVisitor *> visitors) {
1348  EdgeBuilder EB(PD, PDB);
1349  const SourceManager& SM = PDB.getSourceManager();
1350  StackDiagVector CallStack;
1351  InterestingExprs IE;
1352
1353  const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin());
1354  while (NextNode) {
1355    N = NextNode;
1356    NextNode = N->getFirstPred();
1357    ProgramPoint P = N->getLocation();
1358
1359    do {
1360      if (Optional<PostStmt> PS = P.getAs<PostStmt>()) {
1361        if (const Expr *Ex = PS->getStmtAs<Expr>())
1362          reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1363                                              N->getState().getPtr(), Ex,
1364                                              N->getLocationContext());
1365      }
1366
1367      if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
1368        const Stmt *S = CE->getCalleeContext()->getCallSite();
1369        if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) {
1370            reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1371                                                N->getState().getPtr(), Ex,
1372                                                N->getLocationContext());
1373        }
1374
1375        PathDiagnosticCallPiece *C =
1376          PathDiagnosticCallPiece::construct(N, *CE, SM);
1377        LCM[&C->path] = CE->getCalleeContext();
1378
1379        EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true);
1380        EB.flushLocations();
1381
1382        PD.getActivePath().push_front(C);
1383        PD.pushActivePath(&C->path);
1384        CallStack.push_back(StackDiagPair(C, N));
1385        break;
1386      }
1387
1388      // Pop the call hierarchy if we are done walking the contents
1389      // of a function call.
1390      if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
1391        // Add an edge to the start of the function.
1392        const Decl *D = CE->getCalleeContext()->getDecl();
1393        PathDiagnosticLocation pos =
1394          PathDiagnosticLocation::createBegin(D, SM);
1395        EB.addEdge(pos);
1396
1397        // Flush all locations, and pop the active path.
1398        bool VisitedEntireCall = PD.isWithinCall();
1399        EB.flushLocations();
1400        PD.popActivePath();
1401        PDB.LC = N->getLocationContext();
1402
1403        // Either we just added a bunch of stuff to the top-level path, or
1404        // we have a previous CallExitEnd.  If the former, it means that the
1405        // path terminated within a function call.  We must then take the
1406        // current contents of the active path and place it within
1407        // a new PathDiagnosticCallPiece.
1408        PathDiagnosticCallPiece *C;
1409        if (VisitedEntireCall) {
1410          C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
1411        } else {
1412          const Decl *Caller = CE->getLocationContext()->getDecl();
1413          C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
1414          LCM[&C->path] = CE->getCalleeContext();
1415        }
1416
1417        C->setCallee(*CE, SM);
1418        EB.addContext(C->getLocation());
1419
1420        if (!CallStack.empty()) {
1421          assert(CallStack.back().first == C);
1422          CallStack.pop_back();
1423        }
1424        break;
1425      }
1426
1427      // Note that is important that we update the LocationContext
1428      // after looking at CallExits.  CallExit basically adds an
1429      // edge in the *caller*, so we don't want to update the LocationContext
1430      // too soon.
1431      PDB.LC = N->getLocationContext();
1432
1433      // Block edges.
1434      if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
1435        // Does this represent entering a call?  If so, look at propagating
1436        // interesting symbols across call boundaries.
1437        if (NextNode) {
1438          const LocationContext *CallerCtx = NextNode->getLocationContext();
1439          const LocationContext *CalleeCtx = PDB.LC;
1440          if (CallerCtx != CalleeCtx) {
1441            reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
1442                                               N->getState().getPtr(),
1443                                               CalleeCtx, CallerCtx);
1444          }
1445        }
1446
1447        // Are we jumping to the head of a loop?  Add a special diagnostic.
1448        if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
1449          PathDiagnosticLocation L(Loop, SM, PDB.LC);
1450          const CompoundStmt *CS = NULL;
1451
1452          if (const ForStmt *FS = dyn_cast<ForStmt>(Loop))
1453            CS = dyn_cast<CompoundStmt>(FS->getBody());
1454          else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop))
1455            CS = dyn_cast<CompoundStmt>(WS->getBody());
1456
1457          PathDiagnosticEventPiece *p =
1458            new PathDiagnosticEventPiece(L,
1459                                        "Looping back to the head of the loop");
1460          p->setPrunable(true);
1461
1462          EB.addEdge(p->getLocation(), true);
1463          PD.getActivePath().push_front(p);
1464
1465          if (CS) {
1466            PathDiagnosticLocation BL =
1467              PathDiagnosticLocation::createEndBrace(CS, SM);
1468            EB.addEdge(BL);
1469          }
1470        }
1471
1472        const CFGBlock *BSrc = BE->getSrc();
1473        ParentMap &PM = PDB.getParentMap();
1474
1475        if (const Stmt *Term = BSrc->getTerminator()) {
1476          // Are we jumping past the loop body without ever executing the
1477          // loop (because the condition was false)?
1478          if (isLoopJumpPastBody(Term, &*BE) &&
1479              !isInLoopBody(PM,
1480                            getStmtBeforeCond(PM,
1481                                              BSrc->getTerminatorCondition(),
1482                                              N),
1483                            Term)) {
1484            PathDiagnosticLocation L(Term, SM, PDB.LC);
1485            PathDiagnosticEventPiece *PE =
1486                new PathDiagnosticEventPiece(L, "Loop body executed 0 times");
1487            PE->setPrunable(true);
1488
1489            EB.addEdge(PE->getLocation(), true);
1490            PD.getActivePath().push_front(PE);
1491          }
1492
1493          // In any case, add the terminator as the current statement
1494          // context for control edges.
1495          EB.addContext(Term);
1496        }
1497
1498        break;
1499      }
1500
1501      if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) {
1502        Optional<CFGElement> First = BE->getFirstElement();
1503        if (Optional<CFGStmt> S = First ? First->getAs<CFGStmt>() : None) {
1504          const Stmt *stmt = S->getStmt();
1505          if (IsControlFlowExpr(stmt)) {
1506            // Add the proper context for '&&', '||', and '?'.
1507            EB.addContext(stmt);
1508          }
1509          else
1510            EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt());
1511        }
1512
1513        break;
1514      }
1515
1516
1517    } while (0);
1518
1519    if (!NextNode)
1520      continue;
1521
1522    // Add pieces from custom visitors.
1523    BugReport *R = PDB.getBugReport();
1524    for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(),
1525                                                  E = visitors.end();
1526         I != E; ++I) {
1527      if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) {
1528        const PathDiagnosticLocation &Loc = p->getLocation();
1529        EB.addEdge(Loc, true);
1530        PD.getActivePath().push_front(p);
1531        updateStackPiecesWithMessage(p, CallStack);
1532
1533        if (const Stmt *S = Loc.asStmt())
1534          EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt());
1535      }
1536    }
1537  }
1538
1539  return PDB.getBugReport()->isValid();
1540}
1541
1542/// \brief Adds a sanitized control-flow diagnostic edge to a path.
1543static void addEdgeToPath(PathPieces &path,
1544                          PathDiagnosticLocation &PrevLoc,
1545                          PathDiagnosticLocation NewLoc,
1546                          const LocationContext *LC) {
1547  if (!NewLoc.isValid())
1548    return;
1549
1550  SourceLocation NewLocL = NewLoc.asLocation();
1551  if (NewLocL.isInvalid() || NewLocL.isMacroID())
1552    return;
1553
1554  if (!PrevLoc.isValid()) {
1555    PrevLoc = NewLoc;
1556    return;
1557  }
1558
1559  // FIXME: ignore intra-macro edges for now.
1560  if (NewLoc.asLocation().getExpansionLoc() ==
1561      PrevLoc.asLocation().getExpansionLoc())
1562    return;
1563
1564  path.push_front(new PathDiagnosticControlFlowPiece(NewLoc,
1565                                                     PrevLoc));
1566  PrevLoc = NewLoc;
1567}
1568
1569/// A customized wrapper for CFGBlock::getTerminatorCondition()
1570/// which returns the element for ObjCForCollectionStmts.
1571static const Stmt *getTerminatorCondition(const CFGBlock *B) {
1572  const Stmt *S = B->getTerminatorCondition();
1573  if (const ObjCForCollectionStmt *FS =
1574      dyn_cast_or_null<ObjCForCollectionStmt>(S))
1575    return FS->getElement();
1576  return S;
1577}
1578
1579static bool
1580GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD,
1581                                         PathDiagnosticBuilder &PDB,
1582                                         const ExplodedNode *N,
1583                                         LocationContextMap &LCM,
1584                                      ArrayRef<BugReporterVisitor *> visitors) {
1585
1586  BugReport *report = PDB.getBugReport();
1587  const SourceManager& SM = PDB.getSourceManager();
1588  StackDiagVector CallStack;
1589  InterestingExprs IE;
1590
1591  // Record the last location for a given visited stack frame.
1592  llvm::DenseMap<const StackFrameContext *, PathDiagnosticLocation>
1593    PrevLocMap;
1594  PrevLocMap[N->getLocationContext()->getCurrentStackFrame()] =
1595    PD.getLocation();
1596
1597  const ExplodedNode *NextNode = N->getFirstPred();
1598  while (NextNode) {
1599    N = NextNode;
1600    NextNode = N->getFirstPred();
1601    ProgramPoint P = N->getLocation();
1602
1603    do {
1604      // Have we encountered an entrance to a call?  It may be
1605      // the case that we have not encountered a matching
1606      // call exit before this point.  This means that the path
1607      // terminated within the call itself.
1608      if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
1609        // Did we visit an entire call?
1610        bool VisitedEntireCall = PD.isWithinCall();
1611        PD.popActivePath();
1612
1613        PathDiagnosticCallPiece *C;
1614        if (VisitedEntireCall) {
1615          PathDiagnosticPiece *P = PD.getActivePath().front().getPtr();
1616          C = cast<PathDiagnosticCallPiece>(P);
1617        } else {
1618          const Decl *Caller = CE->getLocationContext()->getDecl();
1619          C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
1620
1621          // Since we just transferred the path over to the call piece,
1622          // reset the mapping from active to location context.
1623          assert(PD.getActivePath().size() == 1 &&
1624                 PD.getActivePath().front() == C);
1625          LCM[&PD.getActivePath()] = 0;
1626
1627          // Record the location context mapping for the path within
1628          // the call.
1629          assert(LCM[&C->path] == 0 ||
1630                 LCM[&C->path] == CE->getCalleeContext());
1631          LCM[&C->path] = CE->getCalleeContext();
1632
1633          // If this is the first item in the active path, record
1634          // the new mapping from active path to location context.
1635          const LocationContext *&NewLC = LCM[&PD.getActivePath()];
1636          if (!NewLC) {
1637            NewLC = N->getLocationContext();
1638          }
1639          PDB.LC = NewLC;
1640
1641          // Update the previous location in the active path
1642          // since we just created the call piece lazily.
1643          PrevLocMap[PDB.LC->getCurrentStackFrame()] = C->getLocation();
1644        }
1645        C->setCallee(*CE, SM);
1646
1647        if (!CallStack.empty()) {
1648          assert(CallStack.back().first == C);
1649          CallStack.pop_back();
1650        }
1651        break;
1652      }
1653
1654      // Query the location context here and the previous location
1655      // as processing CallEnter may change the active path.
1656      PDB.LC = N->getLocationContext();
1657
1658      // Get the previous location for the current active
1659      // location context.  All edges will be based on this
1660      // location, and it will be updated in place.
1661      PathDiagnosticLocation &PrevLoc =
1662        PrevLocMap[PDB.LC->getCurrentStackFrame()];
1663
1664      // Record the mapping from the active path to the location
1665      // context.
1666      assert(!LCM[&PD.getActivePath()] ||
1667             LCM[&PD.getActivePath()] == PDB.LC);
1668      LCM[&PD.getActivePath()] = PDB.LC;
1669
1670      // Have we encountered an exit from a function call?
1671      if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
1672        const Stmt *S = CE->getCalleeContext()->getCallSite();
1673        // Propagate the interesting symbols accordingly.
1674        if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) {
1675          reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1676                                              N->getState().getPtr(), Ex,
1677                                              N->getLocationContext());
1678        }
1679
1680        // We are descending into a call (backwards).  Construct
1681        // a new call piece to contain the path pieces for that call.
1682        PathDiagnosticCallPiece *C =
1683          PathDiagnosticCallPiece::construct(N, *CE, SM);
1684
1685        // Record the location context for this call piece.
1686        LCM[&C->path] = CE->getCalleeContext();
1687
1688        // Add the edge to the return site.
1689        addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, PDB.LC);
1690        PD.getActivePath().push_front(C);
1691
1692        // Make the contents of the call the active path for now.
1693        PD.pushActivePath(&C->path);
1694        CallStack.push_back(StackDiagPair(C, N));
1695        break;
1696      }
1697
1698      if (Optional<PostStmt> PS = P.getAs<PostStmt>()) {
1699        // For expressions, make sure we propagate the
1700        // interesting symbols correctly.
1701        if (const Expr *Ex = PS->getStmtAs<Expr>())
1702          reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1703                                              N->getState().getPtr(), Ex,
1704                                              N->getLocationContext());
1705
1706        // Add an edge.  If this is an ObjCForCollectionStmt do
1707        // not add an edge here as it appears in the CFG both
1708        // as a terminator and as a terminator condition.
1709        if (!isa<ObjCForCollectionStmt>(PS->getStmt())) {
1710          PathDiagnosticLocation L =
1711            PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC);
1712          addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC);
1713        }
1714        break;
1715      }
1716
1717      // Block edges.
1718      if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
1719        // Does this represent entering a call?  If so, look at propagating
1720        // interesting symbols across call boundaries.
1721        if (NextNode) {
1722          const LocationContext *CallerCtx = NextNode->getLocationContext();
1723          const LocationContext *CalleeCtx = PDB.LC;
1724          if (CallerCtx != CalleeCtx) {
1725            reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
1726                                               N->getState().getPtr(),
1727                                               CalleeCtx, CallerCtx);
1728          }
1729        }
1730
1731        // Are we jumping to the head of a loop?  Add a special diagnostic.
1732        if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
1733          PathDiagnosticLocation L(Loop, SM, PDB.LC);
1734          const CompoundStmt *CS = NULL;
1735
1736          if (const ForStmt *FS = dyn_cast<ForStmt>(Loop))
1737            CS = dyn_cast<CompoundStmt>(FS->getBody());
1738          else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop))
1739            CS = dyn_cast<CompoundStmt>(WS->getBody());
1740          else if (const ObjCForCollectionStmt *OFS =
1741                   dyn_cast<ObjCForCollectionStmt>(Loop)) {
1742            CS = dyn_cast<CompoundStmt>(OFS->getBody());
1743          }
1744
1745          PathDiagnosticEventPiece *p =
1746            new PathDiagnosticEventPiece(L, "Looping back to the head "
1747                                            "of the loop");
1748          p->setPrunable(true);
1749
1750          addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC);
1751          PD.getActivePath().push_front(p);
1752
1753          if (CS) {
1754            addEdgeToPath(PD.getActivePath(), PrevLoc,
1755                          PathDiagnosticLocation::createEndBrace(CS, SM),
1756                          PDB.LC);
1757          }
1758        }
1759
1760        const CFGBlock *BSrc = BE->getSrc();
1761        ParentMap &PM = PDB.getParentMap();
1762
1763        if (const Stmt *Term = BSrc->getTerminator()) {
1764          // Are we jumping past the loop body without ever executing the
1765          // loop (because the condition was false)?
1766          if (isLoop(Term)) {
1767            const Stmt *TermCond = getTerminatorCondition(BSrc);
1768            bool IsInLoopBody =
1769              isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term);
1770
1771            const char *str = 0;
1772
1773            if (isJumpToFalseBranch(&*BE)) {
1774              if (!IsInLoopBody) {
1775                str = "Loop body executed 0 times";
1776              }
1777            }
1778            else {
1779              str = "Entering loop body";
1780            }
1781
1782            if (str) {
1783              PathDiagnosticLocation L(TermCond, SM, PDB.LC);
1784              PathDiagnosticEventPiece *PE =
1785                new PathDiagnosticEventPiece(L, str);
1786              PE->setPrunable(true);
1787              addEdgeToPath(PD.getActivePath(), PrevLoc,
1788                            PE->getLocation(), PDB.LC);
1789              PD.getActivePath().push_front(PE);
1790            }
1791          }
1792          else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) ||
1793                   isa<GotoStmt>(Term)) {
1794            PathDiagnosticLocation L(Term, SM, PDB.LC);
1795            addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC);
1796          }
1797        }
1798        break;
1799      }
1800    } while (0);
1801
1802    if (!NextNode)
1803      continue;
1804
1805    // Since the active path may have been updated prior
1806    // to this point, query the active location context now.
1807    PathDiagnosticLocation &PrevLoc =
1808      PrevLocMap[PDB.LC->getCurrentStackFrame()];
1809
1810    // Add pieces from custom visitors.
1811    for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(),
1812         E = visitors.end();
1813         I != E; ++I) {
1814      if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) {
1815        addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC);
1816        PD.getActivePath().push_front(p);
1817        updateStackPiecesWithMessage(p, CallStack);
1818      }
1819    }
1820  }
1821
1822  return report->isValid();
1823}
1824
1825const Stmt *getLocStmt(PathDiagnosticLocation L) {
1826  if (!L.isValid())
1827    return 0;
1828  return L.asStmt();
1829}
1830
1831const Stmt *getStmtParent(const Stmt *S, ParentMap &PM) {
1832  if (!S)
1833    return 0;
1834
1835  while (true) {
1836    S = PM.getParentIgnoreParens(S);
1837
1838    if (!S)
1839      break;
1840
1841    if (isa<ExprWithCleanups>(S) ||
1842        isa<CXXBindTemporaryExpr>(S) ||
1843        isa<SubstNonTypeTemplateParmExpr>(S))
1844      continue;
1845
1846    break;
1847  }
1848
1849  return S;
1850}
1851
1852static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) {
1853  switch (S->getStmtClass()) {
1854    case Stmt::BinaryOperatorClass: {
1855      const BinaryOperator *BO = cast<BinaryOperator>(S);
1856      if (!BO->isLogicalOp())
1857        return false;
1858      return BO->getLHS() == Cond || BO->getRHS() == Cond;
1859    }
1860    case Stmt::IfStmtClass:
1861      return cast<IfStmt>(S)->getCond() == Cond;
1862    case Stmt::ForStmtClass:
1863      return cast<ForStmt>(S)->getCond() == Cond;
1864    case Stmt::WhileStmtClass:
1865      return cast<WhileStmt>(S)->getCond() == Cond;
1866    case Stmt::DoStmtClass:
1867      return cast<DoStmt>(S)->getCond() == Cond;
1868    case Stmt::ChooseExprClass:
1869      return cast<ChooseExpr>(S)->getCond() == Cond;
1870    case Stmt::IndirectGotoStmtClass:
1871      return cast<IndirectGotoStmt>(S)->getTarget() == Cond;
1872    case Stmt::SwitchStmtClass:
1873      return cast<SwitchStmt>(S)->getCond() == Cond;
1874    case Stmt::BinaryConditionalOperatorClass:
1875      return cast<BinaryConditionalOperator>(S)->getCond() == Cond;
1876    case Stmt::ConditionalOperatorClass: {
1877      const ConditionalOperator *CO = cast<ConditionalOperator>(S);
1878      return CO->getCond() == Cond ||
1879             CO->getLHS() == Cond ||
1880             CO->getRHS() == Cond;
1881    }
1882    case Stmt::ObjCForCollectionStmtClass:
1883      return cast<ObjCForCollectionStmt>(S)->getElement() == Cond;
1884    default:
1885      return false;
1886  }
1887}
1888
1889static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) {
1890  const ForStmt *FS = dyn_cast<ForStmt>(FL);
1891  if (!FS)
1892    return false;
1893  return FS->getInc() == S || FS->getInit() == S;
1894}
1895
1896typedef llvm::DenseSet<const PathDiagnosticCallPiece *>
1897        OptimizedCallsSet;
1898
1899void PathPieces::dump() const {
1900  unsigned index = 0;
1901  for (PathPieces::const_iterator I = begin(), E = end(); I != E; ++I ) {
1902    llvm::errs() << "[" << index++ << "]";
1903
1904    switch ((*I)->getKind()) {
1905    case PathDiagnosticPiece::Call:
1906      llvm::errs() << "  CALL\n--------------\n";
1907
1908      if (const Stmt *SLoc = getLocStmt((*I)->getLocation())) {
1909        SLoc->dump();
1910      } else {
1911        const PathDiagnosticCallPiece *Call = cast<PathDiagnosticCallPiece>(*I);
1912        if (const NamedDecl *ND = dyn_cast<NamedDecl>(Call->getCallee()))
1913          llvm::errs() << *ND << "\n";
1914      }
1915      break;
1916    case PathDiagnosticPiece::Event:
1917      llvm::errs() << "  EVENT\n--------------\n";
1918      llvm::errs() << (*I)->getString() << "\n";
1919      if (const Stmt *SLoc = getLocStmt((*I)->getLocation())) {
1920        llvm::errs() << " ---- at ----\n";
1921        SLoc->dump();
1922      }
1923      break;
1924    case PathDiagnosticPiece::Macro:
1925      llvm::errs() << "  MACRO\n--------------\n";
1926      // FIXME: print which macro is being invoked.
1927      break;
1928    case PathDiagnosticPiece::ControlFlow: {
1929      const PathDiagnosticControlFlowPiece *CP =
1930        cast<PathDiagnosticControlFlowPiece>(*I);
1931      llvm::errs() << "  CONTROL\n--------------\n";
1932
1933      if (const Stmt *s1Start = getLocStmt(CP->getStartLocation()))
1934        s1Start->dump();
1935      else
1936        llvm::errs() << "NULL\n";
1937
1938      llvm::errs() << " ---- to ----\n";
1939
1940      if (const Stmt *s1End = getLocStmt(CP->getEndLocation()))
1941        s1End->dump();
1942      else
1943        llvm::errs() << "NULL\n";
1944
1945      break;
1946    }
1947    }
1948
1949    llvm::errs() << "\n";
1950  }
1951}
1952
1953/// \brief Return true if X is contained by Y.
1954static bool lexicalContains(ParentMap &PM,
1955                            const Stmt *X,
1956                            const Stmt *Y) {
1957  while (X) {
1958    if (X == Y)
1959      return true;
1960    X = PM.getParent(X);
1961  }
1962  return false;
1963}
1964
1965// Remove short edges on the same line less than 3 columns in difference.
1966static void removePunyEdges(PathPieces &path,
1967                            SourceManager &SM,
1968                            ParentMap &PM) {
1969
1970  bool erased = false;
1971
1972  for (PathPieces::iterator I = path.begin(), E = path.end(); I != E;
1973       erased ? I : ++I) {
1974
1975    erased = false;
1976
1977    PathDiagnosticControlFlowPiece *PieceI =
1978      dyn_cast<PathDiagnosticControlFlowPiece>(*I);
1979
1980    if (!PieceI)
1981      continue;
1982
1983    const Stmt *start = getLocStmt(PieceI->getStartLocation());
1984    const Stmt *end   = getLocStmt(PieceI->getEndLocation());
1985
1986    if (!start || !end)
1987      continue;
1988
1989    const Stmt *endParent = PM.getParent(end);
1990    if (!endParent)
1991      continue;
1992
1993    if (isConditionForTerminator(end, endParent))
1994      continue;
1995
1996    bool Invalid = false;
1997    FullSourceLoc StartL(start->getLocStart(), SM);
1998    FullSourceLoc EndL(end->getLocStart(), SM);
1999
2000    unsigned startLine = StartL.getSpellingLineNumber(&Invalid);
2001    if (Invalid)
2002      continue;
2003
2004    unsigned endLine = EndL.getSpellingLineNumber(&Invalid);
2005    if (Invalid)
2006      continue;
2007
2008    if (startLine != endLine)
2009      continue;
2010
2011    unsigned startCol = StartL.getSpellingColumnNumber(&Invalid);
2012    if (Invalid)
2013      continue;
2014
2015    unsigned endCol = EndL.getSpellingColumnNumber(&Invalid);
2016    if (Invalid)
2017      continue;
2018
2019    if (abs(startCol - endCol) <= 2) {
2020      I = path.erase(I);
2021      erased = true;
2022      continue;
2023    }
2024  }
2025}
2026
2027static void removeIdenticalEvents(PathPieces &path) {
2028  for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) {
2029    PathDiagnosticEventPiece *PieceI =
2030      dyn_cast<PathDiagnosticEventPiece>(*I);
2031
2032    if (!PieceI)
2033      continue;
2034
2035    PathPieces::iterator NextI = I; ++NextI;
2036    if (NextI == E)
2037      return;
2038
2039    PathDiagnosticEventPiece *PieceNextI =
2040      dyn_cast<PathDiagnosticEventPiece>(*I);
2041
2042    if (!PieceNextI)
2043      continue;
2044
2045    // Erase the second piece if it has the same exact message text.
2046    if (PieceI->getString() == PieceNextI->getString()) {
2047      path.erase(NextI);
2048    }
2049  }
2050}
2051
2052static bool optimizeEdges(PathPieces &path, SourceManager &SM,
2053                          OptimizedCallsSet &OCS,
2054                          LocationContextMap &LCM) {
2055  bool hasChanges = false;
2056  const LocationContext *LC = LCM[&path];
2057  assert(LC);
2058  ParentMap &PM = LC->getParentMap();
2059  bool isFirst = true;
2060
2061  for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
2062    bool wasFirst = isFirst;
2063    isFirst = false;
2064
2065    // Optimize subpaths.
2066    if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){
2067      // Record the fact that a call has been optimized so we only do the
2068      // effort once.
2069      if (!OCS.count(CallI)) {
2070        while (optimizeEdges(CallI->path, SM, OCS, LCM)) {}
2071        OCS.insert(CallI);
2072      }
2073      ++I;
2074      continue;
2075    }
2076
2077    // Pattern match the current piece and its successor.
2078    PathDiagnosticControlFlowPiece *PieceI =
2079      dyn_cast<PathDiagnosticControlFlowPiece>(*I);
2080
2081    if (!PieceI) {
2082      ++I;
2083      continue;
2084    }
2085
2086    const Stmt *s1Start = getLocStmt(PieceI->getStartLocation());
2087    const Stmt *s1End   = getLocStmt(PieceI->getEndLocation());
2088    const Stmt *level1 = getStmtParent(s1Start, PM);
2089    const Stmt *level2 = getStmtParent(s1End, PM);
2090
2091    if (wasFirst) {
2092      // If the first edge (in isolation) is just a transition from
2093      // an expression to a parent expression then eliminate that edge.
2094      if (level1 && level2 && level2 == PM.getParent(level1)) {
2095        path.erase(I);
2096        // Since we are erasing the current edge at the start of the
2097        // path, just return now so we start analyzing the start of the path
2098        // again.
2099        return true;
2100      }
2101
2102      // If the first edge (in isolation) is a transition from the
2103      // initialization or increment in a for loop then remove it.
2104      if (level1 && isIncrementOrInitInForLoop(s1Start, level1)) {
2105        path.erase(I);
2106        return true;
2107      }
2108    }
2109
2110    PathPieces::iterator NextI = I; ++NextI;
2111    if (NextI == E)
2112      break;
2113
2114    PathDiagnosticControlFlowPiece *PieceNextI =
2115      dyn_cast<PathDiagnosticControlFlowPiece>(*NextI);
2116
2117    if (!PieceNextI) {
2118      ++I;
2119      continue;
2120    }
2121
2122    const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation());
2123    const Stmt *s2End   = getLocStmt(PieceNextI->getEndLocation());
2124    const Stmt *level3 = getStmtParent(s2Start, PM);
2125    const Stmt *level4 = getStmtParent(s2End, PM);
2126
2127    // Rule I.
2128    //
2129    // If we have two consecutive control edges whose end/begin locations
2130    // are at the same level (e.g. statements or top-level expressions within
2131    // a compound statement, or siblings share a single ancestor expression),
2132    // then merge them if they have no interesting intermediate event.
2133    //
2134    // For example:
2135    //
2136    // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common
2137    // parent is '1'.  Here 'x.y.z' represents the hierarchy of statements.
2138    //
2139    // NOTE: this will be limited later in cases where we add barriers
2140    // to prevent this optimization.
2141    //
2142    if (level1 && level1 == level2 && level1 == level3 && level1 == level4) {
2143      PieceI->setEndLocation(PieceNextI->getEndLocation());
2144      path.erase(NextI);
2145      hasChanges = true;
2146      continue;
2147    }
2148
2149    // Rule II.
2150    //
2151    // Eliminate edges between subexpressions and parent expressions
2152    // when the subexpression is consumed.
2153    //
2154    // NOTE: this will be limited later in cases where we add barriers
2155    // to prevent this optimization.
2156    //
2157    if (s1End && s1End == s2Start && level2) {
2158      bool removeEdge = false;
2159      // Remove edges into the increment or initialization of a
2160      // loop that have no interleaving event.  This means that
2161      // they aren't interesting.
2162      if (isIncrementOrInitInForLoop(s1End, level2))
2163        removeEdge = true;
2164      // Next only consider edges that are not anchored on
2165      // the condition of a terminator.  This are intermediate edges
2166      // that we might want to trim.
2167      else if (!isConditionForTerminator(level2, s1End)) {
2168        // Trim edges on expressions that are consumed by
2169        // the parent expression.
2170        if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) {
2171          removeEdge = true;
2172        }
2173        // Trim edges where a lexical containment doesn't exist.
2174        // For example:
2175        //
2176        //  X -> Y -> Z
2177        //
2178        // If 'Z' lexically contains Y (it is an ancestor) and
2179        // 'X' does not lexically contain Y (it is a descendant OR
2180        // it has no lexical relationship at all) then trim.
2181        //
2182        // This can eliminate edges where we dive into a subexpression
2183        // and then pop back out, etc.
2184        else if (s1Start && s2End &&
2185                 lexicalContains(PM, s2Start, s2End) &&
2186                 !lexicalContains(PM, s1End, s1Start)) {
2187          removeEdge = true;
2188        }
2189      }
2190
2191      if (removeEdge) {
2192        PieceI->setEndLocation(PieceNextI->getEndLocation());
2193        path.erase(NextI);
2194        hasChanges = true;
2195        continue;
2196      }
2197    }
2198
2199    // Optimize edges for ObjC fast-enumeration loops.
2200    //
2201    // (X -> collection) -> (collection -> element)
2202    //
2203    // becomes:
2204    //
2205    // (X -> element)
2206    if (s1End == s2Start) {
2207      const ObjCForCollectionStmt *FS =
2208        dyn_cast_or_null<ObjCForCollectionStmt>(level3);
2209      if (FS && FS->getCollection()->IgnoreParens() == s2Start &&
2210          s2End == FS->getElement()) {
2211        PieceI->setEndLocation(PieceNextI->getEndLocation());
2212        path.erase(NextI);
2213        hasChanges = true;
2214        continue;
2215      }
2216    }
2217
2218    // No changes at this index?  Move to the next one.
2219    ++I;
2220  }
2221
2222  if (!hasChanges) {
2223    // Remove any puny edges left over after primary optimization pass.
2224    removePunyEdges(path, SM, PM);
2225    // Remove identical events.
2226    removeIdenticalEvents(path);
2227  }
2228
2229  return hasChanges;
2230}
2231
2232static void adjustBranchEdges(PathPieces &pieces, LocationContextMap &LCM,
2233                            SourceManager &SM) {
2234  // Retrieve the parent map for this path.
2235  const LocationContext *LC = LCM[&pieces];
2236  ParentMap &PM = LC->getParentMap();
2237  PathPieces::iterator Prev = pieces.end();
2238  for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E;
2239       Prev = I, ++I) {
2240    // Adjust edges in subpaths.
2241    if (PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I)) {
2242      adjustBranchEdges(Call->path, LCM, SM);
2243      continue;
2244    }
2245
2246    PathDiagnosticControlFlowPiece *PieceI =
2247      dyn_cast<PathDiagnosticControlFlowPiece>(*I);
2248
2249    if (!PieceI)
2250      continue;
2251
2252    // We are looking at two edges.  Is the second one incident
2253    // on an expression (or subexpression) of a branch condition.
2254    const Stmt *Dst = getLocStmt(PieceI->getEndLocation());
2255    const Stmt *Src = getLocStmt(PieceI->getStartLocation());
2256
2257    if (!Dst || !Src)
2258      continue;
2259
2260    const Stmt *Branch = 0;
2261    const Stmt *S = Dst;
2262    while (const Stmt *Parent = getStmtParent(S, PM)) {
2263      if (const ForStmt *FS = dyn_cast<ForStmt>(Parent)) {
2264        if (FS->getCond()->IgnoreParens() == S)
2265          Branch = FS;
2266        break;
2267      }
2268      if (const WhileStmt *WS = dyn_cast<WhileStmt>(Parent)) {
2269        if (WS->getCond()->IgnoreParens() == S)
2270          Branch = WS;
2271        break;
2272      }
2273      if (const IfStmt *IS = dyn_cast<IfStmt>(Parent)) {
2274        if (IS->getCond()->IgnoreParens() == S)
2275          Branch = IS;
2276        break;
2277      }
2278      if (const ObjCForCollectionStmt *OFS =
2279          dyn_cast<ObjCForCollectionStmt>(Parent)) {
2280        if (OFS->getElement() == S)
2281          Branch = OFS;
2282        break;
2283      }
2284
2285      S = Parent;
2286    }
2287
2288    // If 'Branch' is non-null we have found a match where we have an edge
2289    // incident on the condition of a if/for/while statement.
2290    if (!Branch)
2291      continue;
2292
2293    // If the current source of the edge is the if/for/while, then there is
2294    // nothing left to be done.
2295    if (Src == Branch)
2296      continue;
2297
2298    // Now look at the previous edge.  We want to know if this was in the same
2299    // "level" as the for statement.
2300    const Stmt *SrcParent = getStmtParent(Src, PM);
2301    const Stmt *BranchParent = getStmtParent(Branch, PM);
2302    if (SrcParent && SrcParent == BranchParent) {
2303      PathDiagnosticLocation L(Branch, SM, LC);
2304      bool needsEdge = true;
2305
2306      if (Prev != E) {
2307        if (PathDiagnosticControlFlowPiece *P =
2308            dyn_cast<PathDiagnosticControlFlowPiece>(*Prev)) {
2309          const Stmt *PrevSrc = getLocStmt(P->getStartLocation());
2310          if (PrevSrc) {
2311            const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM);
2312            if (PrevSrcParent == BranchParent) {
2313              P->setEndLocation(L);
2314              needsEdge = false;
2315            }
2316          }
2317        }
2318      }
2319
2320      if (needsEdge) {
2321        PathDiagnosticControlFlowPiece *P =
2322          new PathDiagnosticControlFlowPiece(PieceI->getStartLocation(), L);
2323        pieces.insert(I, P);
2324      }
2325
2326      PieceI->setStartLocation(L);
2327    }
2328  }
2329}
2330
2331//===----------------------------------------------------------------------===//
2332// Methods for BugType and subclasses.
2333//===----------------------------------------------------------------------===//
2334BugType::~BugType() { }
2335
2336void BugType::FlushReports(BugReporter &BR) {}
2337
2338void BuiltinBug::anchor() {}
2339
2340//===----------------------------------------------------------------------===//
2341// Methods for BugReport and subclasses.
2342//===----------------------------------------------------------------------===//
2343
2344void BugReport::NodeResolver::anchor() {}
2345
2346void BugReport::addVisitor(BugReporterVisitor* visitor) {
2347  if (!visitor)
2348    return;
2349
2350  llvm::FoldingSetNodeID ID;
2351  visitor->Profile(ID);
2352  void *InsertPos;
2353
2354  if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
2355    delete visitor;
2356    return;
2357  }
2358
2359  CallbacksSet.InsertNode(visitor, InsertPos);
2360  Callbacks.push_back(visitor);
2361  ++ConfigurationChangeToken;
2362}
2363
2364BugReport::~BugReport() {
2365  for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) {
2366    delete *I;
2367  }
2368  while (!interestingSymbols.empty()) {
2369    popInterestingSymbolsAndRegions();
2370  }
2371}
2372
2373const Decl *BugReport::getDeclWithIssue() const {
2374  if (DeclWithIssue)
2375    return DeclWithIssue;
2376
2377  const ExplodedNode *N = getErrorNode();
2378  if (!N)
2379    return 0;
2380
2381  const LocationContext *LC = N->getLocationContext();
2382  return LC->getCurrentStackFrame()->getDecl();
2383}
2384
2385void BugReport::Profile(llvm::FoldingSetNodeID& hash) const {
2386  hash.AddPointer(&BT);
2387  hash.AddString(Description);
2388  PathDiagnosticLocation UL = getUniqueingLocation();
2389  if (UL.isValid()) {
2390    UL.Profile(hash);
2391  } else if (Location.isValid()) {
2392    Location.Profile(hash);
2393  } else {
2394    assert(ErrorNode);
2395    hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode));
2396  }
2397
2398  for (SmallVectorImpl<SourceRange>::const_iterator I =
2399      Ranges.begin(), E = Ranges.end(); I != E; ++I) {
2400    const SourceRange range = *I;
2401    if (!range.isValid())
2402      continue;
2403    hash.AddInteger(range.getBegin().getRawEncoding());
2404    hash.AddInteger(range.getEnd().getRawEncoding());
2405  }
2406}
2407
2408void BugReport::markInteresting(SymbolRef sym) {
2409  if (!sym)
2410    return;
2411
2412  // If the symbol wasn't already in our set, note a configuration change.
2413  if (getInterestingSymbols().insert(sym).second)
2414    ++ConfigurationChangeToken;
2415
2416  if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym))
2417    getInterestingRegions().insert(meta->getRegion());
2418}
2419
2420void BugReport::markInteresting(const MemRegion *R) {
2421  if (!R)
2422    return;
2423
2424  // If the base region wasn't already in our set, note a configuration change.
2425  R = R->getBaseRegion();
2426  if (getInterestingRegions().insert(R).second)
2427    ++ConfigurationChangeToken;
2428
2429  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
2430    getInterestingSymbols().insert(SR->getSymbol());
2431}
2432
2433void BugReport::markInteresting(SVal V) {
2434  markInteresting(V.getAsRegion());
2435  markInteresting(V.getAsSymbol());
2436}
2437
2438void BugReport::markInteresting(const LocationContext *LC) {
2439  if (!LC)
2440    return;
2441  InterestingLocationContexts.insert(LC);
2442}
2443
2444bool BugReport::isInteresting(SVal V) {
2445  return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol());
2446}
2447
2448bool BugReport::isInteresting(SymbolRef sym) {
2449  if (!sym)
2450    return false;
2451  // We don't currently consider metadata symbols to be interesting
2452  // even if we know their region is interesting. Is that correct behavior?
2453  return getInterestingSymbols().count(sym);
2454}
2455
2456bool BugReport::isInteresting(const MemRegion *R) {
2457  if (!R)
2458    return false;
2459  R = R->getBaseRegion();
2460  bool b = getInterestingRegions().count(R);
2461  if (b)
2462    return true;
2463  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
2464    return getInterestingSymbols().count(SR->getSymbol());
2465  return false;
2466}
2467
2468bool BugReport::isInteresting(const LocationContext *LC) {
2469  if (!LC)
2470    return false;
2471  return InterestingLocationContexts.count(LC);
2472}
2473
2474void BugReport::lazyInitializeInterestingSets() {
2475  if (interestingSymbols.empty()) {
2476    interestingSymbols.push_back(new Symbols());
2477    interestingRegions.push_back(new Regions());
2478  }
2479}
2480
2481BugReport::Symbols &BugReport::getInterestingSymbols() {
2482  lazyInitializeInterestingSets();
2483  return *interestingSymbols.back();
2484}
2485
2486BugReport::Regions &BugReport::getInterestingRegions() {
2487  lazyInitializeInterestingSets();
2488  return *interestingRegions.back();
2489}
2490
2491void BugReport::pushInterestingSymbolsAndRegions() {
2492  interestingSymbols.push_back(new Symbols(getInterestingSymbols()));
2493  interestingRegions.push_back(new Regions(getInterestingRegions()));
2494}
2495
2496void BugReport::popInterestingSymbolsAndRegions() {
2497  delete interestingSymbols.back();
2498  interestingSymbols.pop_back();
2499  delete interestingRegions.back();
2500  interestingRegions.pop_back();
2501}
2502
2503const Stmt *BugReport::getStmt() const {
2504  if (!ErrorNode)
2505    return 0;
2506
2507  ProgramPoint ProgP = ErrorNode->getLocation();
2508  const Stmt *S = NULL;
2509
2510  if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) {
2511    CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
2512    if (BE->getBlock() == &Exit)
2513      S = GetPreviousStmt(ErrorNode);
2514  }
2515  if (!S)
2516    S = PathDiagnosticLocation::getStmt(ErrorNode);
2517
2518  return S;
2519}
2520
2521std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator>
2522BugReport::getRanges() {
2523    // If no custom ranges, add the range of the statement corresponding to
2524    // the error node.
2525    if (Ranges.empty()) {
2526      if (const Expr *E = dyn_cast_or_null<Expr>(getStmt()))
2527        addRange(E->getSourceRange());
2528      else
2529        return std::make_pair(ranges_iterator(), ranges_iterator());
2530    }
2531
2532    // User-specified absence of range info.
2533    if (Ranges.size() == 1 && !Ranges.begin()->isValid())
2534      return std::make_pair(ranges_iterator(), ranges_iterator());
2535
2536    return std::make_pair(Ranges.begin(), Ranges.end());
2537}
2538
2539PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const {
2540  if (ErrorNode) {
2541    assert(!Location.isValid() &&
2542     "Either Location or ErrorNode should be specified but not both.");
2543    return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM);
2544  } else {
2545    assert(Location.isValid());
2546    return Location;
2547  }
2548
2549  return PathDiagnosticLocation();
2550}
2551
2552//===----------------------------------------------------------------------===//
2553// Methods for BugReporter and subclasses.
2554//===----------------------------------------------------------------------===//
2555
2556BugReportEquivClass::~BugReportEquivClass() { }
2557GRBugReporter::~GRBugReporter() { }
2558BugReporterData::~BugReporterData() {}
2559
2560ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); }
2561
2562ProgramStateManager&
2563GRBugReporter::getStateManager() { return Eng.getStateManager(); }
2564
2565BugReporter::~BugReporter() {
2566  FlushReports();
2567
2568  // Free the bug reports we are tracking.
2569  typedef std::vector<BugReportEquivClass *> ContTy;
2570  for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end();
2571       I != E; ++I) {
2572    delete *I;
2573  }
2574}
2575
2576void BugReporter::FlushReports() {
2577  if (BugTypes.isEmpty())
2578    return;
2579
2580  // First flush the warnings for each BugType.  This may end up creating new
2581  // warnings and new BugTypes.
2582  // FIXME: Only NSErrorChecker needs BugType's FlushReports.
2583  // Turn NSErrorChecker into a proper checker and remove this.
2584  SmallVector<const BugType*, 16> bugTypes;
2585  for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I)
2586    bugTypes.push_back(*I);
2587  for (SmallVector<const BugType*, 16>::iterator
2588         I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I)
2589    const_cast<BugType*>(*I)->FlushReports(*this);
2590
2591  // We need to flush reports in deterministic order to ensure the order
2592  // of the reports is consistent between runs.
2593  typedef std::vector<BugReportEquivClass *> ContVecTy;
2594  for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end();
2595       EI != EE; ++EI){
2596    BugReportEquivClass& EQ = **EI;
2597    FlushReport(EQ);
2598  }
2599
2600  // BugReporter owns and deletes only BugTypes created implicitly through
2601  // EmitBasicReport.
2602  // FIXME: There are leaks from checkers that assume that the BugTypes they
2603  // create will be destroyed by the BugReporter.
2604  for (llvm::StringMap<BugType*>::iterator
2605         I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I)
2606    delete I->second;
2607
2608  // Remove all references to the BugType objects.
2609  BugTypes = F.getEmptySet();
2610}
2611
2612//===----------------------------------------------------------------------===//
2613// PathDiagnostics generation.
2614//===----------------------------------------------------------------------===//
2615
2616namespace {
2617/// A wrapper around a report graph, which contains only a single path, and its
2618/// node maps.
2619class ReportGraph {
2620public:
2621  InterExplodedGraphMap BackMap;
2622  OwningPtr<ExplodedGraph> Graph;
2623  const ExplodedNode *ErrorNode;
2624  size_t Index;
2625};
2626
2627/// A wrapper around a trimmed graph and its node maps.
2628class TrimmedGraph {
2629  InterExplodedGraphMap InverseMap;
2630
2631  typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy;
2632  PriorityMapTy PriorityMap;
2633
2634  typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair;
2635  SmallVector<NodeIndexPair, 32> ReportNodes;
2636
2637  OwningPtr<ExplodedGraph> G;
2638
2639  /// A helper class for sorting ExplodedNodes by priority.
2640  template <bool Descending>
2641  class PriorityCompare {
2642    const PriorityMapTy &PriorityMap;
2643
2644  public:
2645    PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {}
2646
2647    bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const {
2648      PriorityMapTy::const_iterator LI = PriorityMap.find(LHS);
2649      PriorityMapTy::const_iterator RI = PriorityMap.find(RHS);
2650      PriorityMapTy::const_iterator E = PriorityMap.end();
2651
2652      if (LI == E)
2653        return Descending;
2654      if (RI == E)
2655        return !Descending;
2656
2657      return Descending ? LI->second > RI->second
2658                        : LI->second < RI->second;
2659    }
2660
2661    bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const {
2662      return (*this)(LHS.first, RHS.first);
2663    }
2664  };
2665
2666public:
2667  TrimmedGraph(const ExplodedGraph *OriginalGraph,
2668               ArrayRef<const ExplodedNode *> Nodes);
2669
2670  bool popNextReportGraph(ReportGraph &GraphWrapper);
2671};
2672}
2673
2674TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph,
2675                           ArrayRef<const ExplodedNode *> Nodes) {
2676  // The trimmed graph is created in the body of the constructor to ensure
2677  // that the DenseMaps have been initialized already.
2678  InterExplodedGraphMap ForwardMap;
2679  G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap));
2680
2681  // Find the (first) error node in the trimmed graph.  We just need to consult
2682  // the node map which maps from nodes in the original graph to nodes
2683  // in the new graph.
2684  llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes;
2685
2686  for (unsigned i = 0, count = Nodes.size(); i < count; ++i) {
2687    if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) {
2688      ReportNodes.push_back(std::make_pair(NewNode, i));
2689      RemainingNodes.insert(NewNode);
2690    }
2691  }
2692
2693  assert(!RemainingNodes.empty() && "No error node found in the trimmed graph");
2694
2695  // Perform a forward BFS to find all the shortest paths.
2696  std::queue<const ExplodedNode *> WS;
2697
2698  assert(G->num_roots() == 1);
2699  WS.push(*G->roots_begin());
2700  unsigned Priority = 0;
2701
2702  while (!WS.empty()) {
2703    const ExplodedNode *Node = WS.front();
2704    WS.pop();
2705
2706    PriorityMapTy::iterator PriorityEntry;
2707    bool IsNew;
2708    llvm::tie(PriorityEntry, IsNew) =
2709      PriorityMap.insert(std::make_pair(Node, Priority));
2710    ++Priority;
2711
2712    if (!IsNew) {
2713      assert(PriorityEntry->second <= Priority);
2714      continue;
2715    }
2716
2717    if (RemainingNodes.erase(Node))
2718      if (RemainingNodes.empty())
2719        break;
2720
2721    for (ExplodedNode::const_pred_iterator I = Node->succ_begin(),
2722                                           E = Node->succ_end();
2723         I != E; ++I)
2724      WS.push(*I);
2725  }
2726
2727  // Sort the error paths from longest to shortest.
2728  std::sort(ReportNodes.begin(), ReportNodes.end(),
2729            PriorityCompare<true>(PriorityMap));
2730}
2731
2732bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) {
2733  if (ReportNodes.empty())
2734    return false;
2735
2736  const ExplodedNode *OrigN;
2737  llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val();
2738  assert(PriorityMap.find(OrigN) != PriorityMap.end() &&
2739         "error node not accessible from root");
2740
2741  // Create a new graph with a single path.  This is the graph
2742  // that will be returned to the caller.
2743  ExplodedGraph *GNew = new ExplodedGraph();
2744  GraphWrapper.Graph.reset(GNew);
2745  GraphWrapper.BackMap.clear();
2746
2747  // Now walk from the error node up the BFS path, always taking the
2748  // predeccessor with the lowest number.
2749  ExplodedNode *Succ = 0;
2750  while (true) {
2751    // Create the equivalent node in the new graph with the same state
2752    // and location.
2753    ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(),
2754                                       OrigN->isSink());
2755
2756    // Store the mapping to the original node.
2757    InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN);
2758    assert(IMitr != InverseMap.end() && "No mapping to original node.");
2759    GraphWrapper.BackMap[NewN] = IMitr->second;
2760
2761    // Link up the new node with the previous node.
2762    if (Succ)
2763      Succ->addPredecessor(NewN, *GNew);
2764    else
2765      GraphWrapper.ErrorNode = NewN;
2766
2767    Succ = NewN;
2768
2769    // Are we at the final node?
2770    if (OrigN->pred_empty()) {
2771      GNew->addRoot(NewN);
2772      break;
2773    }
2774
2775    // Find the next predeccessor node.  We choose the node that is marked
2776    // with the lowest BFS number.
2777    OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(),
2778                          PriorityCompare<false>(PriorityMap));
2779  }
2780
2781  return true;
2782}
2783
2784
2785/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object
2786///  and collapses PathDiagosticPieces that are expanded by macros.
2787static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) {
2788  typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>,
2789                                SourceLocation> > MacroStackTy;
2790
2791  typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> >
2792          PiecesTy;
2793
2794  MacroStackTy MacroStack;
2795  PiecesTy Pieces;
2796
2797  for (PathPieces::const_iterator I = path.begin(), E = path.end();
2798       I!=E; ++I) {
2799
2800    PathDiagnosticPiece *piece = I->getPtr();
2801
2802    // Recursively compact calls.
2803    if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){
2804      CompactPathDiagnostic(call->path, SM);
2805    }
2806
2807    // Get the location of the PathDiagnosticPiece.
2808    const FullSourceLoc Loc = piece->getLocation().asLocation();
2809
2810    // Determine the instantiation location, which is the location we group
2811    // related PathDiagnosticPieces.
2812    SourceLocation InstantiationLoc = Loc.isMacroID() ?
2813                                      SM.getExpansionLoc(Loc) :
2814                                      SourceLocation();
2815
2816    if (Loc.isFileID()) {
2817      MacroStack.clear();
2818      Pieces.push_back(piece);
2819      continue;
2820    }
2821
2822    assert(Loc.isMacroID());
2823
2824    // Is the PathDiagnosticPiece within the same macro group?
2825    if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
2826      MacroStack.back().first->subPieces.push_back(piece);
2827      continue;
2828    }
2829
2830    // We aren't in the same group.  Are we descending into a new macro
2831    // or are part of an old one?
2832    IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup;
2833
2834    SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
2835                                          SM.getExpansionLoc(Loc) :
2836                                          SourceLocation();
2837
2838    // Walk the entire macro stack.
2839    while (!MacroStack.empty()) {
2840      if (InstantiationLoc == MacroStack.back().second) {
2841        MacroGroup = MacroStack.back().first;
2842        break;
2843      }
2844
2845      if (ParentInstantiationLoc == MacroStack.back().second) {
2846        MacroGroup = MacroStack.back().first;
2847        break;
2848      }
2849
2850      MacroStack.pop_back();
2851    }
2852
2853    if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) {
2854      // Create a new macro group and add it to the stack.
2855      PathDiagnosticMacroPiece *NewGroup =
2856        new PathDiagnosticMacroPiece(
2857          PathDiagnosticLocation::createSingleLocation(piece->getLocation()));
2858
2859      if (MacroGroup)
2860        MacroGroup->subPieces.push_back(NewGroup);
2861      else {
2862        assert(InstantiationLoc.isFileID());
2863        Pieces.push_back(NewGroup);
2864      }
2865
2866      MacroGroup = NewGroup;
2867      MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc));
2868    }
2869
2870    // Finally, add the PathDiagnosticPiece to the group.
2871    MacroGroup->subPieces.push_back(piece);
2872  }
2873
2874  // Now take the pieces and construct a new PathDiagnostic.
2875  path.clear();
2876
2877  for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I)
2878    path.push_back(*I);
2879}
2880
2881bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD,
2882                                           PathDiagnosticConsumer &PC,
2883                                           ArrayRef<BugReport *> &bugReports) {
2884  assert(!bugReports.empty());
2885
2886  bool HasValid = false;
2887  bool HasInvalid = false;
2888  SmallVector<const ExplodedNode *, 32> errorNodes;
2889  for (ArrayRef<BugReport*>::iterator I = bugReports.begin(),
2890                                      E = bugReports.end(); I != E; ++I) {
2891    if ((*I)->isValid()) {
2892      HasValid = true;
2893      errorNodes.push_back((*I)->getErrorNode());
2894    } else {
2895      // Keep the errorNodes list in sync with the bugReports list.
2896      HasInvalid = true;
2897      errorNodes.push_back(0);
2898    }
2899  }
2900
2901  // If all the reports have been marked invalid by a previous path generation,
2902  // we're done.
2903  if (!HasValid)
2904    return false;
2905
2906  typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme;
2907  PathGenerationScheme ActiveScheme = PC.getGenerationScheme();
2908
2909  if (ActiveScheme == PathDiagnosticConsumer::Extensive) {
2910    AnalyzerOptions &options = getAnalyzerOptions();
2911    if (options.getBooleanOption("path-diagnostics-alternate", false)) {
2912      ActiveScheme = PathDiagnosticConsumer::AlternateExtensive;
2913    }
2914  }
2915
2916  TrimmedGraph TrimG(&getGraph(), errorNodes);
2917  ReportGraph ErrorGraph;
2918
2919  while (TrimG.popNextReportGraph(ErrorGraph)) {
2920    // Find the BugReport with the original location.
2921    assert(ErrorGraph.Index < bugReports.size());
2922    BugReport *R = bugReports[ErrorGraph.Index];
2923    assert(R && "No original report found for sliced graph.");
2924    assert(R->isValid() && "Report selected by trimmed graph marked invalid.");
2925
2926    // Start building the path diagnostic...
2927    PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC);
2928    const ExplodedNode *N = ErrorGraph.ErrorNode;
2929
2930    // Register additional node visitors.
2931    R->addVisitor(new NilReceiverBRVisitor());
2932    R->addVisitor(new ConditionBRVisitor());
2933    R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor());
2934
2935    BugReport::VisitorList visitors;
2936    unsigned origReportConfigToken, finalReportConfigToken;
2937    LocationContextMap LCM;
2938
2939    // While generating diagnostics, it's possible the visitors will decide
2940    // new symbols and regions are interesting, or add other visitors based on
2941    // the information they find. If they do, we need to regenerate the path
2942    // based on our new report configuration.
2943    do {
2944      // Get a clean copy of all the visitors.
2945      for (BugReport::visitor_iterator I = R->visitor_begin(),
2946                                       E = R->visitor_end(); I != E; ++I)
2947        visitors.push_back((*I)->clone());
2948
2949      // Clear out the active path from any previous work.
2950      PD.resetPath();
2951      origReportConfigToken = R->getConfigurationChangeToken();
2952
2953      // Generate the very last diagnostic piece - the piece is visible before
2954      // the trace is expanded.
2955      PathDiagnosticPiece *LastPiece = 0;
2956      for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end();
2957          I != E; ++I) {
2958        if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) {
2959          assert (!LastPiece &&
2960              "There can only be one final piece in a diagnostic.");
2961          LastPiece = Piece;
2962        }
2963      }
2964
2965      if (ActiveScheme != PathDiagnosticConsumer::None) {
2966        if (!LastPiece)
2967          LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R);
2968        assert(LastPiece);
2969        PD.setEndOfPath(LastPiece);
2970      }
2971
2972      // Make sure we get a clean location context map so we don't
2973      // hold onto old mappings.
2974      LCM.clear();
2975
2976      switch (ActiveScheme) {
2977      case PathDiagnosticConsumer::AlternateExtensive:
2978        GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors);
2979        break;
2980      case PathDiagnosticConsumer::Extensive:
2981        GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors);
2982        break;
2983      case PathDiagnosticConsumer::Minimal:
2984        GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors);
2985        break;
2986      case PathDiagnosticConsumer::None:
2987        GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors);
2988        break;
2989      }
2990
2991      // Clean up the visitors we used.
2992      llvm::DeleteContainerPointers(visitors);
2993
2994      // Did anything change while generating this path?
2995      finalReportConfigToken = R->getConfigurationChangeToken();
2996    } while (finalReportConfigToken != origReportConfigToken);
2997
2998    if (!R->isValid())
2999      continue;
3000
3001    // Finally, prune the diagnostic path of uninteresting stuff.
3002    if (!PD.path.empty()) {
3003      // Remove messages that are basically the same.
3004      removeRedundantMsgs(PD.getMutablePieces());
3005
3006      if (R->shouldPrunePath() && getAnalyzerOptions().shouldPrunePaths()) {
3007        bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM);
3008        assert(stillHasNotes);
3009        (void)stillHasNotes;
3010      }
3011
3012      adjustCallLocations(PD.getMutablePieces());
3013
3014      if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) {
3015        SourceManager &SM = getSourceManager();
3016
3017        // Reduce the number of edges from a very conservative set
3018        // to an aesthetically pleasing subset that conveys the
3019        // necessary information.
3020        OptimizedCallsSet OCS;
3021        while (optimizeEdges(PD.getMutablePieces(), SM, OCS, LCM)) {}
3022
3023        // Adjust edges into loop conditions to make them more uniform
3024        // and aesthetically pleasing.
3025        adjustBranchEdges(PD.getMutablePieces(), LCM, SM);
3026      }
3027    }
3028
3029    // We found a report and didn't suppress it.
3030    return true;
3031  }
3032
3033  // We suppressed all the reports in this equivalence class.
3034  assert(!HasInvalid && "Inconsistent suppression");
3035  (void)HasInvalid;
3036  return false;
3037}
3038
3039void BugReporter::Register(BugType *BT) {
3040  BugTypes = F.add(BugTypes, BT);
3041}
3042
3043void BugReporter::emitReport(BugReport* R) {
3044  // Compute the bug report's hash to determine its equivalence class.
3045  llvm::FoldingSetNodeID ID;
3046  R->Profile(ID);
3047
3048  // Lookup the equivance class.  If there isn't one, create it.
3049  BugType& BT = R->getBugType();
3050  Register(&BT);
3051  void *InsertPos;
3052  BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
3053
3054  if (!EQ) {
3055    EQ = new BugReportEquivClass(R);
3056    EQClasses.InsertNode(EQ, InsertPos);
3057    EQClassesVector.push_back(EQ);
3058  }
3059  else
3060    EQ->AddReport(R);
3061}
3062
3063
3064//===----------------------------------------------------------------------===//
3065// Emitting reports in equivalence classes.
3066//===----------------------------------------------------------------------===//
3067
3068namespace {
3069struct FRIEC_WLItem {
3070  const ExplodedNode *N;
3071  ExplodedNode::const_succ_iterator I, E;
3072
3073  FRIEC_WLItem(const ExplodedNode *n)
3074  : N(n), I(N->succ_begin()), E(N->succ_end()) {}
3075};
3076}
3077
3078static BugReport *
3079FindReportInEquivalenceClass(BugReportEquivClass& EQ,
3080                             SmallVectorImpl<BugReport*> &bugReports) {
3081
3082  BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end();
3083  assert(I != E);
3084  BugType& BT = I->getBugType();
3085
3086  // If we don't need to suppress any of the nodes because they are
3087  // post-dominated by a sink, simply add all the nodes in the equivalence class
3088  // to 'Nodes'.  Any of the reports will serve as a "representative" report.
3089  if (!BT.isSuppressOnSink()) {
3090    BugReport *R = I;
3091    for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) {
3092      const ExplodedNode *N = I->getErrorNode();
3093      if (N) {
3094        R = I;
3095        bugReports.push_back(R);
3096      }
3097    }
3098    return R;
3099  }
3100
3101  // For bug reports that should be suppressed when all paths are post-dominated
3102  // by a sink node, iterate through the reports in the equivalence class
3103  // until we find one that isn't post-dominated (if one exists).  We use a
3104  // DFS traversal of the ExplodedGraph to find a non-sink node.  We could write
3105  // this as a recursive function, but we don't want to risk blowing out the
3106  // stack for very long paths.
3107  BugReport *exampleReport = 0;
3108
3109  for (; I != E; ++I) {
3110    const ExplodedNode *errorNode = I->getErrorNode();
3111
3112    if (!errorNode)
3113      continue;
3114    if (errorNode->isSink()) {
3115      llvm_unreachable(
3116           "BugType::isSuppressSink() should not be 'true' for sink end nodes");
3117    }
3118    // No successors?  By definition this nodes isn't post-dominated by a sink.
3119    if (errorNode->succ_empty()) {
3120      bugReports.push_back(I);
3121      if (!exampleReport)
3122        exampleReport = I;
3123      continue;
3124    }
3125
3126    // At this point we know that 'N' is not a sink and it has at least one
3127    // successor.  Use a DFS worklist to find a non-sink end-of-path node.
3128    typedef FRIEC_WLItem WLItem;
3129    typedef SmallVector<WLItem, 10> DFSWorkList;
3130    llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
3131
3132    DFSWorkList WL;
3133    WL.push_back(errorNode);
3134    Visited[errorNode] = 1;
3135
3136    while (!WL.empty()) {
3137      WLItem &WI = WL.back();
3138      assert(!WI.N->succ_empty());
3139
3140      for (; WI.I != WI.E; ++WI.I) {
3141        const ExplodedNode *Succ = *WI.I;
3142        // End-of-path node?
3143        if (Succ->succ_empty()) {
3144          // If we found an end-of-path node that is not a sink.
3145          if (!Succ->isSink()) {
3146            bugReports.push_back(I);
3147            if (!exampleReport)
3148              exampleReport = I;
3149            WL.clear();
3150            break;
3151          }
3152          // Found a sink?  Continue on to the next successor.
3153          continue;
3154        }
3155        // Mark the successor as visited.  If it hasn't been explored,
3156        // enqueue it to the DFS worklist.
3157        unsigned &mark = Visited[Succ];
3158        if (!mark) {
3159          mark = 1;
3160          WL.push_back(Succ);
3161          break;
3162        }
3163      }
3164
3165      // The worklist may have been cleared at this point.  First
3166      // check if it is empty before checking the last item.
3167      if (!WL.empty() && &WL.back() == &WI)
3168        WL.pop_back();
3169    }
3170  }
3171
3172  // ExampleReport will be NULL if all the nodes in the equivalence class
3173  // were post-dominated by sinks.
3174  return exampleReport;
3175}
3176
3177void BugReporter::FlushReport(BugReportEquivClass& EQ) {
3178  SmallVector<BugReport*, 10> bugReports;
3179  BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports);
3180  if (exampleReport) {
3181    const PathDiagnosticConsumers &C = getPathDiagnosticConsumers();
3182    for (PathDiagnosticConsumers::const_iterator I=C.begin(),
3183                                                 E=C.end(); I != E; ++I) {
3184      FlushReport(exampleReport, **I, bugReports);
3185    }
3186  }
3187}
3188
3189void BugReporter::FlushReport(BugReport *exampleReport,
3190                              PathDiagnosticConsumer &PD,
3191                              ArrayRef<BugReport*> bugReports) {
3192
3193  // FIXME: Make sure we use the 'R' for the path that was actually used.
3194  // Probably doesn't make a difference in practice.
3195  BugType& BT = exampleReport->getBugType();
3196
3197  OwningPtr<PathDiagnostic>
3198    D(new PathDiagnostic(exampleReport->getDeclWithIssue(),
3199                         exampleReport->getBugType().getName(),
3200                         exampleReport->getDescription(),
3201                         exampleReport->getShortDescription(/*Fallback=*/false),
3202                         BT.getCategory(),
3203                         exampleReport->getUniqueingLocation(),
3204                         exampleReport->getUniqueingDecl()));
3205
3206  MaxBugClassSize = std::max(bugReports.size(),
3207                             static_cast<size_t>(MaxBugClassSize));
3208
3209  // Generate the full path diagnostic, using the generation scheme
3210  // specified by the PathDiagnosticConsumer. Note that we have to generate
3211  // path diagnostics even for consumers which do not support paths, because
3212  // the BugReporterVisitors may mark this bug as a false positive.
3213  if (!bugReports.empty())
3214    if (!generatePathDiagnostic(*D.get(), PD, bugReports))
3215      return;
3216
3217  MaxValidBugClassSize = std::max(bugReports.size(),
3218                                  static_cast<size_t>(MaxValidBugClassSize));
3219
3220  // Examine the report and see if the last piece is in a header. Reset the
3221  // report location to the last piece in the main source file.
3222  AnalyzerOptions& Opts = getAnalyzerOptions();
3223  if (Opts.shouldReportIssuesInMainSourceFile() && !Opts.AnalyzeAll)
3224    D->resetDiagnosticLocationToMainFile();
3225
3226  // If the path is empty, generate a single step path with the location
3227  // of the issue.
3228  if (D->path.empty()) {
3229    PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager());
3230    PathDiagnosticPiece *piece =
3231      new PathDiagnosticEventPiece(L, exampleReport->getDescription());
3232    BugReport::ranges_iterator Beg, End;
3233    llvm::tie(Beg, End) = exampleReport->getRanges();
3234    for ( ; Beg != End; ++Beg)
3235      piece->addRange(*Beg);
3236    D->setEndOfPath(piece);
3237  }
3238
3239  // Get the meta data.
3240  const BugReport::ExtraTextList &Meta = exampleReport->getExtraText();
3241  for (BugReport::ExtraTextList::const_iterator i = Meta.begin(),
3242                                                e = Meta.end(); i != e; ++i) {
3243    D->addMeta(*i);
3244  }
3245
3246  PD.HandlePathDiagnostic(D.take());
3247}
3248
3249void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3250                                  StringRef name,
3251                                  StringRef category,
3252                                  StringRef str, PathDiagnosticLocation Loc,
3253                                  SourceRange* RBeg, unsigned NumRanges) {
3254
3255  // 'BT' is owned by BugReporter.
3256  BugType *BT = getBugTypeForName(name, category);
3257  BugReport *R = new BugReport(*BT, str, Loc);
3258  R->setDeclWithIssue(DeclWithIssue);
3259  for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg);
3260  emitReport(R);
3261}
3262
3263BugType *BugReporter::getBugTypeForName(StringRef name,
3264                                        StringRef category) {
3265  SmallString<136> fullDesc;
3266  llvm::raw_svector_ostream(fullDesc) << name << ":" << category;
3267  llvm::StringMapEntry<BugType *> &
3268      entry = StrBugTypes.GetOrCreateValue(fullDesc);
3269  BugType *BT = entry.getValue();
3270  if (!BT) {
3271    BT = new BugType(name, category);
3272    entry.setValue(BT);
3273  }
3274  return BT;
3275}
3276