BugReporter.cpp revision 097ebb3d8ce55d1f78a3f1e7a0978dbde5ee2898 
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#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
16#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
17#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/Analysis/CFG.h"
20#include "clang/AST/DeclObjC.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ParentMap.h"
23#include "clang/AST/StmtObjC.h"
24#include "clang/Basic/SourceManager.h"
25#include "clang/Analysis/ProgramPoint.h"
26#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
27#include "llvm/Support/raw_ostream.h"
28#include "llvm/ADT/DenseMap.h"
29#include "llvm/ADT/SmallString.h"
30#include "llvm/ADT/STLExtras.h"
31#include "llvm/ADT/OwningPtr.h"
32#include "llvm/ADT/IntrusiveRefCntPtr.h"
33#include <queue>
34
35using namespace clang;
36using namespace ento;
37
38BugReporterVisitor::~BugReporterVisitor() {}
39
40void BugReporterContext::anchor() {}
41
42//===----------------------------------------------------------------------===//
43// Helper routines for walking the ExplodedGraph and fetching statements.
44//===----------------------------------------------------------------------===//
45
46static inline const Stmt *GetStmt(const ProgramPoint &P) {
47  if (const StmtPoint* SP = dyn_cast<StmtPoint>(&P))
48    return SP->getStmt();
49  else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P))
50    return BE->getSrc()->getTerminator();
51
52  return 0;
53}
54
55static inline const ExplodedNode*
56GetPredecessorNode(const ExplodedNode *N) {
57  return N->pred_empty() ? NULL : *(N->pred_begin());
58}
59
60static inline const ExplodedNode*
61GetSuccessorNode(const ExplodedNode *N) {
62  return N->succ_empty() ? NULL : *(N->succ_begin());
63}
64
65static const Stmt *GetPreviousStmt(const ExplodedNode *N) {
66  for (N = GetPredecessorNode(N); N; N = GetPredecessorNode(N))
67    if (const Stmt *S = GetStmt(N->getLocation()))
68      return S;
69
70  return 0;
71}
72
73static const Stmt *GetNextStmt(const ExplodedNode *N) {
74  for (N = GetSuccessorNode(N); N; N = GetSuccessorNode(N))
75    if (const Stmt *S = GetStmt(N->getLocation())) {
76      // Check if the statement is '?' or '&&'/'||'.  These are "merges",
77      // not actual statement points.
78      switch (S->getStmtClass()) {
79        case Stmt::ChooseExprClass:
80        case Stmt::BinaryConditionalOperatorClass: continue;
81        case Stmt::ConditionalOperatorClass: continue;
82        case Stmt::BinaryOperatorClass: {
83          BinaryOperatorKind Op = cast<BinaryOperator>(S)->getOpcode();
84          if (Op == BO_LAnd || Op == BO_LOr)
85            continue;
86          break;
87        }
88        default:
89          break;
90      }
91      return S;
92    }
93
94  return 0;
95}
96
97static inline const Stmt*
98GetCurrentOrPreviousStmt(const ExplodedNode *N) {
99  if (const Stmt *S = GetStmt(N->getLocation()))
100    return S;
101
102  return GetPreviousStmt(N);
103}
104
105static inline const Stmt*
106GetCurrentOrNextStmt(const ExplodedNode *N) {
107  if (const Stmt *S = GetStmt(N->getLocation()))
108    return S;
109
110  return GetNextStmt(N);
111}
112
113//===----------------------------------------------------------------------===//
114// Diagnostic cleanup.
115//===----------------------------------------------------------------------===//
116
117/// Recursively scan through a path and prune out calls and macros pieces
118/// that aren't needed.  Return true if afterwards the path contains
119/// "interesting stuff" which means it should be pruned from the parent path.
120static bool RemoveUneededCalls(PathPieces &pieces) {
121  bool containsSomethingInteresting = false;
122  const unsigned N = pieces.size();
123
124  for (unsigned i = 0 ; i < N ; ++i) {
125    // Remove the front piece from the path.  If it is still something we
126    // want to keep once we are done, we will push it back on the end.
127    IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front());
128    pieces.pop_front();
129
130    switch (piece->getKind()) {
131      case PathDiagnosticPiece::Call: {
132        PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece);
133        // Recursively clean out the subclass.  Keep this call around if
134        // it contains any informative diagnostics.
135        if (!RemoveUneededCalls(call->path))
136          continue;
137        containsSomethingInteresting = true;
138        break;
139      }
140      case PathDiagnosticPiece::Macro: {
141        PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece);
142        if (!RemoveUneededCalls(macro->subPieces))
143          continue;
144        containsSomethingInteresting = true;
145        break;
146      }
147      case PathDiagnosticPiece::Event: {
148        PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece);
149        // We never throw away an event, but we do throw it away wholesale
150        // as part of a path if we throw the entire path away.
151        if (!event->isPrunable())
152          containsSomethingInteresting = true;
153        break;
154      }
155      case PathDiagnosticPiece::ControlFlow:
156        break;
157    }
158
159    pieces.push_back(piece);
160  }
161
162  return containsSomethingInteresting;
163}
164
165//===----------------------------------------------------------------------===//
166// PathDiagnosticBuilder and its associated routines and helper objects.
167//===----------------------------------------------------------------------===//
168
169typedef llvm::DenseMap<const ExplodedNode*,
170const ExplodedNode*> NodeBackMap;
171
172namespace {
173class NodeMapClosure : public BugReport::NodeResolver {
174  NodeBackMap& M;
175public:
176  NodeMapClosure(NodeBackMap *m) : M(*m) {}
177  ~NodeMapClosure() {}
178
179  const ExplodedNode *getOriginalNode(const ExplodedNode *N) {
180    NodeBackMap::iterator I = M.find(N);
181    return I == M.end() ? 0 : I->second;
182  }
183};
184
185class PathDiagnosticBuilder : public BugReporterContext {
186  BugReport *R;
187  PathDiagnosticConsumer *PDC;
188  OwningPtr<ParentMap> PM;
189  NodeMapClosure NMC;
190public:
191  const LocationContext *LC;
192
193  PathDiagnosticBuilder(GRBugReporter &br,
194                        BugReport *r, NodeBackMap *Backmap,
195                        PathDiagnosticConsumer *pdc)
196    : BugReporterContext(br),
197      R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext())
198  {}
199
200  PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N);
201
202  PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os,
203                                            const ExplodedNode *N);
204
205  BugReport *getBugReport() { return R; }
206
207  Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); }
208
209  ParentMap& getParentMap() { return LC->getParentMap(); }
210
211  const Stmt *getParent(const Stmt *S) {
212    return getParentMap().getParent(S);
213  }
214
215  virtual NodeMapClosure& getNodeResolver() { return NMC; }
216
217  PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S);
218
219  PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const {
220    return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive;
221  }
222
223  bool supportsLogicalOpControlFlow() const {
224    return PDC ? PDC->supportsLogicalOpControlFlow() : true;
225  }
226};
227} // end anonymous namespace
228
229PathDiagnosticLocation
230PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) {
231  if (const Stmt *S = GetNextStmt(N))
232    return PathDiagnosticLocation(S, getSourceManager(), LC);
233
234  return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(),
235                                               getSourceManager());
236}
237
238PathDiagnosticLocation
239PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os,
240                                          const ExplodedNode *N) {
241
242  // Slow, but probably doesn't matter.
243  if (os.str().empty())
244    os << ' ';
245
246  const PathDiagnosticLocation &Loc = ExecutionContinues(N);
247
248  if (Loc.asStmt())
249    os << "Execution continues on line "
250       << getSourceManager().getExpansionLineNumber(Loc.asLocation())
251       << '.';
252  else {
253    os << "Execution jumps to the end of the ";
254    const Decl *D = N->getLocationContext()->getDecl();
255    if (isa<ObjCMethodDecl>(D))
256      os << "method";
257    else if (isa<FunctionDecl>(D))
258      os << "function";
259    else {
260      assert(isa<BlockDecl>(D));
261      os << "anonymous block";
262    }
263    os << '.';
264  }
265
266  return Loc;
267}
268
269static bool IsNested(const Stmt *S, ParentMap &PM) {
270  if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S)))
271    return true;
272
273  const Stmt *Parent = PM.getParentIgnoreParens(S);
274
275  if (Parent)
276    switch (Parent->getStmtClass()) {
277      case Stmt::ForStmtClass:
278      case Stmt::DoStmtClass:
279      case Stmt::WhileStmtClass:
280        return true;
281      default:
282        break;
283    }
284
285  return false;
286}
287
288PathDiagnosticLocation
289PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) {
290  assert(S && "Null Stmt *passed to getEnclosingStmtLocation");
291  ParentMap &P = getParentMap();
292  SourceManager &SMgr = getSourceManager();
293
294  while (IsNested(S, P)) {
295    const Stmt *Parent = P.getParentIgnoreParens(S);
296
297    if (!Parent)
298      break;
299
300    switch (Parent->getStmtClass()) {
301      case Stmt::BinaryOperatorClass: {
302        const BinaryOperator *B = cast<BinaryOperator>(Parent);
303        if (B->isLogicalOp())
304          return PathDiagnosticLocation(S, SMgr, LC);
305        break;
306      }
307      case Stmt::CompoundStmtClass:
308      case Stmt::StmtExprClass:
309        return PathDiagnosticLocation(S, SMgr, LC);
310      case Stmt::ChooseExprClass:
311        // Similar to '?' if we are referring to condition, just have the edge
312        // point to the entire choose expression.
313        if (cast<ChooseExpr>(Parent)->getCond() == S)
314          return PathDiagnosticLocation(Parent, SMgr, LC);
315        else
316          return PathDiagnosticLocation(S, SMgr, LC);
317      case Stmt::BinaryConditionalOperatorClass:
318      case Stmt::ConditionalOperatorClass:
319        // For '?', if we are referring to condition, just have the edge point
320        // to the entire '?' expression.
321        if (cast<AbstractConditionalOperator>(Parent)->getCond() == S)
322          return PathDiagnosticLocation(Parent, SMgr, LC);
323        else
324          return PathDiagnosticLocation(S, SMgr, LC);
325      case Stmt::DoStmtClass:
326          return PathDiagnosticLocation(S, SMgr, LC);
327      case Stmt::ForStmtClass:
328        if (cast<ForStmt>(Parent)->getBody() == S)
329          return PathDiagnosticLocation(S, SMgr, LC);
330        break;
331      case Stmt::IfStmtClass:
332        if (cast<IfStmt>(Parent)->getCond() != S)
333          return PathDiagnosticLocation(S, SMgr, LC);
334        break;
335      case Stmt::ObjCForCollectionStmtClass:
336        if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S)
337          return PathDiagnosticLocation(S, SMgr, LC);
338        break;
339      case Stmt::WhileStmtClass:
340        if (cast<WhileStmt>(Parent)->getCond() != S)
341          return PathDiagnosticLocation(S, SMgr, LC);
342        break;
343      default:
344        break;
345    }
346
347    S = Parent;
348  }
349
350  assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
351
352  // Special case: DeclStmts can appear in for statement declarations, in which
353  //  case the ForStmt is the context.
354  if (isa<DeclStmt>(S)) {
355    if (const Stmt *Parent = P.getParent(S)) {
356      switch (Parent->getStmtClass()) {
357        case Stmt::ForStmtClass:
358        case Stmt::ObjCForCollectionStmtClass:
359          return PathDiagnosticLocation(Parent, SMgr, LC);
360        default:
361          break;
362      }
363    }
364  }
365  else if (isa<BinaryOperator>(S)) {
366    // Special case: the binary operator represents the initialization
367    // code in a for statement (this can happen when the variable being
368    // initialized is an old variable.
369    if (const ForStmt *FS =
370          dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) {
371      if (FS->getInit() == S)
372        return PathDiagnosticLocation(FS, SMgr, LC);
373    }
374  }
375
376  return PathDiagnosticLocation(S, SMgr, LC);
377}
378
379//===----------------------------------------------------------------------===//
380// ScanNotableSymbols: closure-like callback for scanning Store bindings.
381//===----------------------------------------------------------------------===//
382
383static const VarDecl* GetMostRecentVarDeclBinding(const ExplodedNode *N,
384                                                  ProgramStateManager& VMgr,
385                                                  SVal X) {
386
387  for ( ; N ; N = N->pred_empty() ? 0 : *N->pred_begin()) {
388
389    ProgramPoint P = N->getLocation();
390
391    if (!isa<PostStmt>(P))
392      continue;
393
394    const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(cast<PostStmt>(P).getStmt());
395
396    if (!DR)
397      continue;
398
399    SVal Y = N->getState()->getSVal(DR, N->getLocationContext());
400
401    if (X != Y)
402      continue;
403
404    const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
405
406    if (!VD)
407      continue;
408
409    return VD;
410  }
411
412  return 0;
413}
414
415namespace {
416class NotableSymbolHandler
417: public StoreManager::BindingsHandler {
418
419  SymbolRef Sym;
420  ProgramStateRef PrevSt;
421  const Stmt *S;
422  ProgramStateManager& VMgr;
423  const ExplodedNode *Pred;
424  PathDiagnostic& PD;
425  BugReporter& BR;
426
427public:
428
429  NotableSymbolHandler(SymbolRef sym,
430                       ProgramStateRef prevst,
431                       const Stmt *s,
432                       ProgramStateManager& vmgr,
433                       const ExplodedNode *pred,
434                       PathDiagnostic& pd,
435                       BugReporter& br)
436  : Sym(sym),
437    PrevSt(prevst),
438    S(s),
439    VMgr(vmgr),
440    Pred(pred),
441    PD(pd),
442    BR(br) {}
443
444  bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R,
445                     SVal V) {
446
447    SymbolRef ScanSym = V.getAsSymbol();
448
449    if (ScanSym != Sym)
450      return true;
451
452    // Check if the previous state has this binding.
453    SVal X = PrevSt->getSVal(loc::MemRegionVal(R));
454
455    if (X == V) // Same binding?
456      return true;
457
458    // Different binding.  Only handle assignments for now.  We don't pull
459    // this check out of the loop because we will eventually handle other
460    // cases.
461
462    VarDecl *VD = 0;
463
464    if (const BinaryOperator* B = dyn_cast<BinaryOperator>(S)) {
465      if (!B->isAssignmentOp())
466        return true;
467
468      // What variable did we assign to?
469      DeclRefExpr *DR = dyn_cast<DeclRefExpr>(B->getLHS()->IgnoreParenCasts());
470
471      if (!DR)
472        return true;
473
474      VD = dyn_cast<VarDecl>(DR->getDecl());
475    }
476    else if (const DeclStmt *DS = dyn_cast<DeclStmt>(S)) {
477      // FIXME: Eventually CFGs won't have DeclStmts.  Right now we
478      //  assume that each DeclStmt has a single Decl.  This invariant
479      //  holds by construction in the CFG.
480      VD = dyn_cast<VarDecl>(*DS->decl_begin());
481    }
482
483    if (!VD)
484      return true;
485
486    // What is the most recently referenced variable with this binding?
487    const VarDecl *MostRecent = GetMostRecentVarDeclBinding(Pred, VMgr, V);
488
489    if (!MostRecent)
490      return true;
491
492    // Create the diagnostic.
493    if (Loc::isLocType(VD->getType())) {
494      SmallString<64> buf;
495      llvm::raw_svector_ostream os(buf);
496      os << '\'' << *VD << "' now aliases '" << *MostRecent << '\'';
497      PathDiagnosticLocation L =
498        PathDiagnosticLocation::createBegin(S, BR.getSourceManager(),
499                                                   Pred->getLocationContext());
500      PD.getActivePath().push_front(new PathDiagnosticEventPiece(L, os.str()));
501    }
502
503    return true;
504  }
505};
506}
507
508static void HandleNotableSymbol(const ExplodedNode *N,
509                                const Stmt *S,
510                                SymbolRef Sym, BugReporter& BR,
511                                PathDiagnostic& PD) {
512
513  const ExplodedNode *Pred = N->pred_empty() ? 0 : *N->pred_begin();
514  ProgramStateRef PrevSt = Pred ? Pred->getState() : 0;
515
516  if (!PrevSt)
517    return;
518
519  // Look at the region bindings of the current state that map to the
520  // specified symbol.  Are any of them not in the previous state?
521  ProgramStateManager& VMgr = cast<GRBugReporter>(BR).getStateManager();
522  NotableSymbolHandler H(Sym, PrevSt, S, VMgr, Pred, PD, BR);
523  cast<GRBugReporter>(BR).getStateManager().iterBindings(N->getState(), H);
524}
525
526namespace {
527class ScanNotableSymbols
528: public StoreManager::BindingsHandler {
529
530  llvm::SmallSet<SymbolRef, 10> AlreadyProcessed;
531  const ExplodedNode *N;
532  const Stmt *S;
533  GRBugReporter& BR;
534  PathDiagnostic& PD;
535
536public:
537  ScanNotableSymbols(const ExplodedNode *n, const Stmt *s,
538                     GRBugReporter& br, PathDiagnostic& pd)
539  : N(n), S(s), BR(br), PD(pd) {}
540
541  bool HandleBinding(StoreManager& SMgr, Store store,
542                     const MemRegion* R, SVal V) {
543
544    SymbolRef ScanSym = V.getAsSymbol();
545
546    if (!ScanSym)
547      return true;
548
549    if (!BR.isNotable(ScanSym))
550      return true;
551
552    if (AlreadyProcessed.count(ScanSym))
553      return true;
554
555    AlreadyProcessed.insert(ScanSym);
556
557    HandleNotableSymbol(N, S, ScanSym, BR, PD);
558    return true;
559  }
560};
561} // end anonymous namespace
562
563//===----------------------------------------------------------------------===//
564// "Minimal" path diagnostic generation algorithm.
565//===----------------------------------------------------------------------===//
566
567static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM);
568
569static void GenerateMinimalPathDiagnostic(PathDiagnostic& PD,
570                                          PathDiagnosticBuilder &PDB,
571                                          const ExplodedNode *N) {
572
573  SourceManager& SMgr = PDB.getSourceManager();
574  const LocationContext *LC = PDB.LC;
575  const ExplodedNode *NextNode = N->pred_empty()
576                                        ? NULL : *(N->pred_begin());
577  while (NextNode) {
578    N = NextNode;
579    PDB.LC = N->getLocationContext();
580    NextNode = GetPredecessorNode(N);
581
582    ProgramPoint P = N->getLocation();
583
584    if (const CallExit *CE = dyn_cast<CallExit>(&P)) {
585      PathDiagnosticCallPiece *C =
586        PathDiagnosticCallPiece::construct(N, *CE, SMgr);
587      PD.getActivePath().push_front(C);
588      PD.pushActivePath(&C->path);
589      continue;
590    }
591
592    if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) {
593      PD.popActivePath();
594      // The current active path should never be empty.  Either we
595      // just added a bunch of stuff to the top-level path, or
596      // we have a previous CallExit.  If the front of the active
597      // path is not a PathDiagnosticCallPiece, it means that the
598      // path terminated within a function call.  We must then take the
599      // current contents of the active path and place it within
600      // a new PathDiagnosticCallPiece.
601      assert(!PD.getActivePath().empty());
602      PathDiagnosticCallPiece *C =
603        dyn_cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
604      if (!C)
605        C = PathDiagnosticCallPiece::construct(PD.getActivePath());
606      C->setCallee(*CE, SMgr);
607      continue;
608    }
609
610    if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
611      const CFGBlock *Src = BE->getSrc();
612      const CFGBlock *Dst = BE->getDst();
613      const Stmt *T = Src->getTerminator();
614
615      if (!T)
616        continue;
617
618      PathDiagnosticLocation Start =
619        PathDiagnosticLocation::createBegin(T, SMgr,
620                                                N->getLocationContext());
621
622      switch (T->getStmtClass()) {
623        default:
624          break;
625
626        case Stmt::GotoStmtClass:
627        case Stmt::IndirectGotoStmtClass: {
628          const Stmt *S = GetNextStmt(N);
629
630          if (!S)
631            continue;
632
633          std::string sbuf;
634          llvm::raw_string_ostream os(sbuf);
635          const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S);
636
637          os << "Control jumps to line "
638          << End.asLocation().getExpansionLineNumber();
639          PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
640                                                                os.str()));
641          break;
642        }
643
644        case Stmt::SwitchStmtClass: {
645          // Figure out what case arm we took.
646          std::string sbuf;
647          llvm::raw_string_ostream os(sbuf);
648
649          if (const Stmt *S = Dst->getLabel()) {
650            PathDiagnosticLocation End(S, SMgr, LC);
651
652            switch (S->getStmtClass()) {
653              default:
654                os << "No cases match in the switch statement. "
655                "Control jumps to line "
656                << End.asLocation().getExpansionLineNumber();
657                break;
658              case Stmt::DefaultStmtClass:
659                os << "Control jumps to the 'default' case at line "
660                << End.asLocation().getExpansionLineNumber();
661                break;
662
663              case Stmt::CaseStmtClass: {
664                os << "Control jumps to 'case ";
665                const CaseStmt *Case = cast<CaseStmt>(S);
666                const Expr *LHS = Case->getLHS()->IgnoreParenCasts();
667
668                // Determine if it is an enum.
669                bool GetRawInt = true;
670
671                if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) {
672                  // FIXME: Maybe this should be an assertion.  Are there cases
673                  // were it is not an EnumConstantDecl?
674                  const EnumConstantDecl *D =
675                    dyn_cast<EnumConstantDecl>(DR->getDecl());
676
677                  if (D) {
678                    GetRawInt = false;
679                    os << *D;
680                  }
681                }
682
683                if (GetRawInt)
684                  os << LHS->EvaluateKnownConstInt(PDB.getASTContext());
685
686                os << ":'  at line "
687                << End.asLocation().getExpansionLineNumber();
688                break;
689              }
690            }
691            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
692                                                             os.str()));
693          }
694          else {
695            os << "'Default' branch taken. ";
696            const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N);
697            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
698                                                             os.str()));
699          }
700
701          break;
702        }
703
704        case Stmt::BreakStmtClass:
705        case Stmt::ContinueStmtClass: {
706          std::string sbuf;
707          llvm::raw_string_ostream os(sbuf);
708          PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
709          PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
710                                                           os.str()));
711          break;
712        }
713
714          // Determine control-flow for ternary '?'.
715        case Stmt::BinaryConditionalOperatorClass:
716        case Stmt::ConditionalOperatorClass: {
717          std::string sbuf;
718          llvm::raw_string_ostream os(sbuf);
719          os << "'?' condition is ";
720
721          if (*(Src->succ_begin()+1) == Dst)
722            os << "false";
723          else
724            os << "true";
725
726          PathDiagnosticLocation End = PDB.ExecutionContinues(N);
727
728          if (const Stmt *S = End.asStmt())
729            End = PDB.getEnclosingStmtLocation(S);
730
731          PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
732                                                           os.str()));
733          break;
734        }
735
736          // Determine control-flow for short-circuited '&&' and '||'.
737        case Stmt::BinaryOperatorClass: {
738          if (!PDB.supportsLogicalOpControlFlow())
739            break;
740
741          const BinaryOperator *B = cast<BinaryOperator>(T);
742          std::string sbuf;
743          llvm::raw_string_ostream os(sbuf);
744          os << "Left side of '";
745
746          if (B->getOpcode() == BO_LAnd) {
747            os << "&&" << "' is ";
748
749            if (*(Src->succ_begin()+1) == Dst) {
750              os << "false";
751              PathDiagnosticLocation End(B->getLHS(), SMgr, LC);
752              PathDiagnosticLocation Start =
753                PathDiagnosticLocation::createOperatorLoc(B, SMgr);
754              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
755                                                               os.str()));
756            }
757            else {
758              os << "true";
759              PathDiagnosticLocation Start(B->getLHS(), SMgr, LC);
760              PathDiagnosticLocation End = PDB.ExecutionContinues(N);
761              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
762                                                               os.str()));
763            }
764          }
765          else {
766            assert(B->getOpcode() == BO_LOr);
767            os << "||" << "' is ";
768
769            if (*(Src->succ_begin()+1) == Dst) {
770              os << "false";
771              PathDiagnosticLocation Start(B->getLHS(), SMgr, LC);
772              PathDiagnosticLocation End = PDB.ExecutionContinues(N);
773              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
774                                                               os.str()));
775            }
776            else {
777              os << "true";
778              PathDiagnosticLocation End(B->getLHS(), SMgr, LC);
779              PathDiagnosticLocation Start =
780                PathDiagnosticLocation::createOperatorLoc(B, SMgr);
781              PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
782                                                               os.str()));
783            }
784          }
785
786          break;
787        }
788
789        case Stmt::DoStmtClass:  {
790          if (*(Src->succ_begin()) == Dst) {
791            std::string sbuf;
792            llvm::raw_string_ostream os(sbuf);
793
794            os << "Loop condition is true. ";
795            PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
796
797            if (const Stmt *S = End.asStmt())
798              End = PDB.getEnclosingStmtLocation(S);
799
800            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
801                                                             os.str()));
802          }
803          else {
804            PathDiagnosticLocation End = PDB.ExecutionContinues(N);
805
806            if (const Stmt *S = End.asStmt())
807              End = PDB.getEnclosingStmtLocation(S);
808
809            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
810                              "Loop condition is false.  Exiting loop"));
811          }
812
813          break;
814        }
815
816        case Stmt::WhileStmtClass:
817        case Stmt::ForStmtClass: {
818          if (*(Src->succ_begin()+1) == Dst) {
819            std::string sbuf;
820            llvm::raw_string_ostream os(sbuf);
821
822            os << "Loop condition is false. ";
823            PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
824            if (const Stmt *S = End.asStmt())
825              End = PDB.getEnclosingStmtLocation(S);
826
827            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
828                                                             os.str()));
829          }
830          else {
831            PathDiagnosticLocation End = PDB.ExecutionContinues(N);
832            if (const Stmt *S = End.asStmt())
833              End = PDB.getEnclosingStmtLocation(S);
834
835            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
836                            "Loop condition is true.  Entering loop body"));
837          }
838
839          break;
840        }
841
842        case Stmt::IfStmtClass: {
843          PathDiagnosticLocation End = PDB.ExecutionContinues(N);
844
845          if (const Stmt *S = End.asStmt())
846            End = PDB.getEnclosingStmtLocation(S);
847
848          if (*(Src->succ_begin()+1) == Dst)
849            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
850                                                        "Taking false branch"));
851          else
852            PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(Start, End,
853                                                         "Taking true branch"));
854
855          break;
856        }
857      }
858    }
859
860    if (NextNode) {
861      // Add diagnostic pieces from custom visitors.
862      BugReport *R = PDB.getBugReport();
863      for (BugReport::visitor_iterator I = R->visitor_begin(),
864           E = R->visitor_end(); I!=E; ++I) {
865        if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R))
866          PD.getActivePath().push_front(p);
867      }
868    }
869
870    if (const PostStmt *PS = dyn_cast<PostStmt>(&P)) {
871      // Scan the region bindings, and see if a "notable" symbol has a new
872      // lval binding.
873      ScanNotableSymbols SNS(N, PS->getStmt(), PDB.getBugReporter(), PD);
874      PDB.getStateManager().iterBindings(N->getState(), SNS);
875    }
876  }
877
878  // After constructing the full PathDiagnostic, do a pass over it to compact
879  // PathDiagnosticPieces that occur within a macro.
880  CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager());
881}
882
883//===----------------------------------------------------------------------===//
884// "Extensive" PathDiagnostic generation.
885//===----------------------------------------------------------------------===//
886
887static bool IsControlFlowExpr(const Stmt *S) {
888  const Expr *E = dyn_cast<Expr>(S);
889
890  if (!E)
891    return false;
892
893  E = E->IgnoreParenCasts();
894
895  if (isa<AbstractConditionalOperator>(E))
896    return true;
897
898  if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E))
899    if (B->isLogicalOp())
900      return true;
901
902  return false;
903}
904
905namespace {
906class ContextLocation : public PathDiagnosticLocation {
907  bool IsDead;
908public:
909  ContextLocation(const PathDiagnosticLocation &L, bool isdead = false)
910    : PathDiagnosticLocation(L), IsDead(isdead) {}
911
912  void markDead() { IsDead = true; }
913  bool isDead() const { return IsDead; }
914};
915
916class EdgeBuilder {
917  std::vector<ContextLocation> CLocs;
918  typedef std::vector<ContextLocation>::iterator iterator;
919  PathDiagnostic &PD;
920  PathDiagnosticBuilder &PDB;
921  PathDiagnosticLocation PrevLoc;
922
923  bool IsConsumedExpr(const PathDiagnosticLocation &L);
924
925  bool containsLocation(const PathDiagnosticLocation &Container,
926                        const PathDiagnosticLocation &Containee);
927
928  PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L);
929
930  PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L,
931                                         bool firstCharOnly = false) {
932    if (const Stmt *S = L.asStmt()) {
933      const Stmt *Original = S;
934      while (1) {
935        // Adjust the location for some expressions that are best referenced
936        // by one of their subexpressions.
937        switch (S->getStmtClass()) {
938          default:
939            break;
940          case Stmt::ParenExprClass:
941          case Stmt::GenericSelectionExprClass:
942            S = cast<Expr>(S)->IgnoreParens();
943            firstCharOnly = true;
944            continue;
945          case Stmt::BinaryConditionalOperatorClass:
946          case Stmt::ConditionalOperatorClass:
947            S = cast<AbstractConditionalOperator>(S)->getCond();
948            firstCharOnly = true;
949            continue;
950          case Stmt::ChooseExprClass:
951            S = cast<ChooseExpr>(S)->getCond();
952            firstCharOnly = true;
953            continue;
954          case Stmt::BinaryOperatorClass:
955            S = cast<BinaryOperator>(S)->getLHS();
956            firstCharOnly = true;
957            continue;
958        }
959
960        break;
961      }
962
963      if (S != Original)
964        L = PathDiagnosticLocation(S, L.getManager(), PDB.LC);
965    }
966
967    if (firstCharOnly)
968      L  = PathDiagnosticLocation::createSingleLocation(L);
969
970    return L;
971  }
972
973  void popLocation() {
974    if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) {
975      // For contexts, we only one the first character as the range.
976      rawAddEdge(cleanUpLocation(CLocs.back(), true));
977    }
978    CLocs.pop_back();
979  }
980
981public:
982  EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb)
983    : PD(pd), PDB(pdb) {
984
985      // If the PathDiagnostic already has pieces, add the enclosing statement
986      // of the first piece as a context as well.
987      if (!PD.path.empty()) {
988        PrevLoc = (*PD.path.begin())->getLocation();
989
990        if (const Stmt *S = PrevLoc.asStmt())
991          addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt());
992      }
993  }
994
995  ~EdgeBuilder() {
996    while (!CLocs.empty()) popLocation();
997
998    // Finally, add an initial edge from the start location of the first
999    // statement (if it doesn't already exist).
1000    PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin(
1001                                                       PDB.LC,
1002                                                       PDB.getSourceManager());
1003    if (L.isValid())
1004      rawAddEdge(L);
1005  }
1006
1007  void flushLocations() {
1008    while (!CLocs.empty())
1009      popLocation();
1010    PrevLoc = PathDiagnosticLocation();
1011  }
1012
1013  void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false);
1014
1015  void rawAddEdge(PathDiagnosticLocation NewLoc);
1016
1017  void addContext(const Stmt *S);
1018  void addExtendedContext(const Stmt *S);
1019};
1020} // end anonymous namespace
1021
1022
1023PathDiagnosticLocation
1024EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) {
1025  if (const Stmt *S = L.asStmt()) {
1026    if (IsControlFlowExpr(S))
1027      return L;
1028
1029    return PDB.getEnclosingStmtLocation(S);
1030  }
1031
1032  return L;
1033}
1034
1035bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container,
1036                                   const PathDiagnosticLocation &Containee) {
1037
1038  if (Container == Containee)
1039    return true;
1040
1041  if (Container.asDecl())
1042    return true;
1043
1044  if (const Stmt *S = Containee.asStmt())
1045    if (const Stmt *ContainerS = Container.asStmt()) {
1046      while (S) {
1047        if (S == ContainerS)
1048          return true;
1049        S = PDB.getParent(S);
1050      }
1051      return false;
1052    }
1053
1054  // Less accurate: compare using source ranges.
1055  SourceRange ContainerR = Container.asRange();
1056  SourceRange ContaineeR = Containee.asRange();
1057
1058  SourceManager &SM = PDB.getSourceManager();
1059  SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin());
1060  SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd());
1061  SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin());
1062  SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd());
1063
1064  unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg);
1065  unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd);
1066  unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg);
1067  unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd);
1068
1069  assert(ContainerBegLine <= ContainerEndLine);
1070  assert(ContaineeBegLine <= ContaineeEndLine);
1071
1072  return (ContainerBegLine <= ContaineeBegLine &&
1073          ContainerEndLine >= ContaineeEndLine &&
1074          (ContainerBegLine != ContaineeBegLine ||
1075           SM.getExpansionColumnNumber(ContainerRBeg) <=
1076           SM.getExpansionColumnNumber(ContaineeRBeg)) &&
1077          (ContainerEndLine != ContaineeEndLine ||
1078           SM.getExpansionColumnNumber(ContainerREnd) >=
1079           SM.getExpansionColumnNumber(ContainerREnd)));
1080}
1081
1082void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) {
1083  if (!PrevLoc.isValid()) {
1084    PrevLoc = NewLoc;
1085    return;
1086  }
1087
1088  const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc);
1089  const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc);
1090
1091  if (NewLocClean.asLocation() == PrevLocClean.asLocation())
1092    return;
1093
1094  // FIXME: Ignore intra-macro edges for now.
1095  if (NewLocClean.asLocation().getExpansionLoc() ==
1096      PrevLocClean.asLocation().getExpansionLoc())
1097    return;
1098
1099  PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean));
1100  PrevLoc = NewLoc;
1101}
1102
1103void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) {
1104
1105  if (!alwaysAdd && NewLoc.asLocation().isMacroID())
1106    return;
1107
1108  const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc);
1109
1110  while (!CLocs.empty()) {
1111    ContextLocation &TopContextLoc = CLocs.back();
1112
1113    // Is the top location context the same as the one for the new location?
1114    if (TopContextLoc == CLoc) {
1115      if (alwaysAdd) {
1116        if (IsConsumedExpr(TopContextLoc) &&
1117            !IsControlFlowExpr(TopContextLoc.asStmt()))
1118            TopContextLoc.markDead();
1119
1120        rawAddEdge(NewLoc);
1121      }
1122
1123      return;
1124    }
1125
1126    if (containsLocation(TopContextLoc, CLoc)) {
1127      if (alwaysAdd) {
1128        rawAddEdge(NewLoc);
1129
1130        if (IsConsumedExpr(CLoc) && !IsControlFlowExpr(CLoc.asStmt())) {
1131          CLocs.push_back(ContextLocation(CLoc, true));
1132          return;
1133        }
1134      }
1135
1136      CLocs.push_back(CLoc);
1137      return;
1138    }
1139
1140    // Context does not contain the location.  Flush it.
1141    popLocation();
1142  }
1143
1144  // If we reach here, there is no enclosing context.  Just add the edge.
1145  rawAddEdge(NewLoc);
1146}
1147
1148bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) {
1149  if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt()))
1150    return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X);
1151
1152  return false;
1153}
1154
1155void EdgeBuilder::addExtendedContext(const Stmt *S) {
1156  if (!S)
1157    return;
1158
1159  const Stmt *Parent = PDB.getParent(S);
1160  while (Parent) {
1161    if (isa<CompoundStmt>(Parent))
1162      Parent = PDB.getParent(Parent);
1163    else
1164      break;
1165  }
1166
1167  if (Parent) {
1168    switch (Parent->getStmtClass()) {
1169      case Stmt::DoStmtClass:
1170      case Stmt::ObjCAtSynchronizedStmtClass:
1171        addContext(Parent);
1172      default:
1173        break;
1174    }
1175  }
1176
1177  addContext(S);
1178}
1179
1180void EdgeBuilder::addContext(const Stmt *S) {
1181  if (!S)
1182    return;
1183
1184  PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC);
1185
1186  while (!CLocs.empty()) {
1187    const PathDiagnosticLocation &TopContextLoc = CLocs.back();
1188
1189    // Is the top location context the same as the one for the new location?
1190    if (TopContextLoc == L)
1191      return;
1192
1193    if (containsLocation(TopContextLoc, L)) {
1194      CLocs.push_back(L);
1195      return;
1196    }
1197
1198    // Context does not contain the location.  Flush it.
1199    popLocation();
1200  }
1201
1202  CLocs.push_back(L);
1203}
1204
1205static void GenerateExtensivePathDiagnostic(PathDiagnostic& PD,
1206                                            PathDiagnosticBuilder &PDB,
1207                                            const ExplodedNode *N) {
1208  EdgeBuilder EB(PD, PDB);
1209  const SourceManager& SM = PDB.getSourceManager();
1210
1211  const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin());
1212  while (NextNode) {
1213    N = NextNode;
1214    NextNode = GetPredecessorNode(N);
1215    ProgramPoint P = N->getLocation();
1216
1217    do {
1218      if (const CallExit *CE = dyn_cast<CallExit>(&P)) {
1219        const StackFrameContext *LCtx =
1220        CE->getLocationContext()->getCurrentStackFrame();
1221        PathDiagnosticLocation Loc(LCtx->getCallSite(),
1222                                   PDB.getSourceManager(),
1223                                   LCtx);
1224        EB.addEdge(Loc, true);
1225        EB.flushLocations();
1226        PathDiagnosticCallPiece *C =
1227          PathDiagnosticCallPiece::construct(N, *CE, SM);
1228        PD.getActivePath().push_front(C);
1229        PD.pushActivePath(&C->path);
1230        break;
1231      }
1232
1233      // Pop the call hierarchy if we are done walking the contents
1234      // of a function call.
1235      if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) {
1236        // Add an edge to the start of the function.
1237        const Decl *D = CE->getCalleeContext()->getDecl();
1238        PathDiagnosticLocation pos =
1239          PathDiagnosticLocation::createBegin(D, SM);
1240        EB.addEdge(pos);
1241
1242        // Flush all locations, and pop the active path.
1243        EB.flushLocations();
1244        PD.popActivePath();
1245        assert(!PD.getActivePath().empty());
1246        PDB.LC = N->getLocationContext();
1247
1248        // The current active path should never be empty.  Either we
1249        // just added a bunch of stuff to the top-level path, or
1250        // we have a previous CallExit.  If the front of the active
1251        // path is not a PathDiagnosticCallPiece, it means that the
1252        // path terminated within a function call.  We must then take the
1253        // current contents of the active path and place it within
1254        // a new PathDiagnosticCallPiece.
1255        PathDiagnosticCallPiece *C =
1256          dyn_cast<PathDiagnosticCallPiece>(PD.getActivePath().front());
1257        if (!C)
1258          C = PathDiagnosticCallPiece::construct(PD.getActivePath());
1259        C->setCallee(*CE, SM);
1260        EB.addContext(CE->getCallExpr());
1261        break;
1262      }
1263
1264      // Note that is important that we update the LocationContext
1265      // after looking at CallExits.  CallExit basically adds an
1266      // edge in the *caller*, so we don't want to update the LocationContext
1267      // too soon.
1268      PDB.LC = N->getLocationContext();
1269
1270      // Block edges.
1271      if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
1272        const CFGBlock &Blk = *BE->getSrc();
1273        const Stmt *Term = Blk.getTerminator();
1274
1275        // Are we jumping to the head of a loop?  Add a special diagnostic.
1276        if (const Stmt *Loop = BE->getDst()->getLoopTarget()) {
1277          PathDiagnosticLocation L(Loop, SM, PDB.LC);
1278          const CompoundStmt *CS = NULL;
1279
1280          if (!Term) {
1281            if (const ForStmt *FS = dyn_cast<ForStmt>(Loop))
1282              CS = dyn_cast<CompoundStmt>(FS->getBody());
1283            else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop))
1284              CS = dyn_cast<CompoundStmt>(WS->getBody());
1285          }
1286
1287          PathDiagnosticEventPiece *p =
1288            new PathDiagnosticEventPiece(L,
1289                                        "Looping back to the head of the loop");
1290          p->setPrunable(true);
1291
1292          EB.addEdge(p->getLocation(), true);
1293          PD.getActivePath().push_front(p);
1294
1295          if (CS) {
1296            PathDiagnosticLocation BL =
1297              PathDiagnosticLocation::createEndBrace(CS, SM);
1298            EB.addEdge(BL);
1299          }
1300        }
1301
1302        if (Term)
1303          EB.addContext(Term);
1304
1305        break;
1306      }
1307
1308      if (const BlockEntrance *BE = dyn_cast<BlockEntrance>(&P)) {
1309        if (const CFGStmt *S = BE->getFirstElement().getAs<CFGStmt>()) {
1310          const Stmt *stmt = S->getStmt();
1311          if (IsControlFlowExpr(stmt)) {
1312            // Add the proper context for '&&', '||', and '?'.
1313            EB.addContext(stmt);
1314          }
1315          else
1316            EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt());
1317        }
1318
1319        break;
1320      }
1321
1322
1323    } while (0);
1324
1325    if (!NextNode)
1326      continue;
1327
1328    // Add pieces from custom visitors.
1329    BugReport *R = PDB.getBugReport();
1330    for (BugReport::visitor_iterator I = R->visitor_begin(),
1331                                     E = R->visitor_end(); I!=E; ++I) {
1332      if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) {
1333        const PathDiagnosticLocation &Loc = p->getLocation();
1334        EB.addEdge(Loc, true);
1335        PD.getActivePath().push_front(p);
1336        if (const Stmt *S = Loc.asStmt())
1337          EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt());
1338      }
1339    }
1340  }
1341}
1342
1343//===----------------------------------------------------------------------===//
1344// Methods for BugType and subclasses.
1345//===----------------------------------------------------------------------===//
1346BugType::~BugType() { }
1347
1348void BugType::FlushReports(BugReporter &BR) {}
1349
1350void BuiltinBug::anchor() {}
1351
1352//===----------------------------------------------------------------------===//
1353// Methods for BugReport and subclasses.
1354//===----------------------------------------------------------------------===//
1355
1356void BugReport::NodeResolver::anchor() {}
1357
1358void BugReport::addVisitor(BugReporterVisitor* visitor) {
1359  if (!visitor)
1360    return;
1361
1362  llvm::FoldingSetNodeID ID;
1363  visitor->Profile(ID);
1364  void *InsertPos;
1365
1366  if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
1367    delete visitor;
1368    return;
1369  }
1370
1371  CallbacksSet.InsertNode(visitor, InsertPos);
1372  Callbacks = F.add(visitor, Callbacks);
1373}
1374
1375BugReport::~BugReport() {
1376  for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) {
1377    delete *I;
1378  }
1379}
1380
1381void BugReport::Profile(llvm::FoldingSetNodeID& hash) const {
1382  hash.AddPointer(&BT);
1383  hash.AddString(Description);
1384  if (UniqueingLocation.isValid()) {
1385    UniqueingLocation.Profile(hash);
1386  } else if (Location.isValid()) {
1387    Location.Profile(hash);
1388  } else {
1389    assert(ErrorNode);
1390    hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode));
1391  }
1392
1393  for (SmallVectorImpl<SourceRange>::const_iterator I =
1394      Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1395    const SourceRange range = *I;
1396    if (!range.isValid())
1397      continue;
1398    hash.AddInteger(range.getBegin().getRawEncoding());
1399    hash.AddInteger(range.getEnd().getRawEncoding());
1400  }
1401}
1402
1403const Stmt *BugReport::getStmt() const {
1404  if (!ErrorNode)
1405    return 0;
1406
1407  ProgramPoint ProgP = ErrorNode->getLocation();
1408  const Stmt *S = NULL;
1409
1410  if (BlockEntrance *BE = dyn_cast<BlockEntrance>(&ProgP)) {
1411    CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
1412    if (BE->getBlock() == &Exit)
1413      S = GetPreviousStmt(ErrorNode);
1414  }
1415  if (!S)
1416    S = GetStmt(ProgP);
1417
1418  return S;
1419}
1420
1421std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator>
1422BugReport::getRanges() {
1423    // If no custom ranges, add the range of the statement corresponding to
1424    // the error node.
1425    if (Ranges.empty()) {
1426      if (const Expr *E = dyn_cast_or_null<Expr>(getStmt()))
1427        addRange(E->getSourceRange());
1428      else
1429        return std::make_pair(ranges_iterator(), ranges_iterator());
1430    }
1431
1432    // User-specified absence of range info.
1433    if (Ranges.size() == 1 && !Ranges.begin()->isValid())
1434      return std::make_pair(ranges_iterator(), ranges_iterator());
1435
1436    return std::make_pair(Ranges.begin(), Ranges.end());
1437}
1438
1439PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const {
1440  if (ErrorNode) {
1441    assert(!Location.isValid() &&
1442     "Either Location or ErrorNode should be specified but not both.");
1443
1444    if (const Stmt *S = GetCurrentOrPreviousStmt(ErrorNode)) {
1445      const LocationContext *LC = ErrorNode->getLocationContext();
1446
1447      // For member expressions, return the location of the '.' or '->'.
1448      if (const MemberExpr *ME = dyn_cast<MemberExpr>(S))
1449        return PathDiagnosticLocation::createMemberLoc(ME, SM);
1450      // For binary operators, return the location of the operator.
1451      if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S))
1452        return PathDiagnosticLocation::createOperatorLoc(B, SM);
1453
1454      return PathDiagnosticLocation::createBegin(S, SM, LC);
1455    }
1456  } else {
1457    assert(Location.isValid());
1458    return Location;
1459  }
1460
1461  return PathDiagnosticLocation();
1462}
1463
1464//===----------------------------------------------------------------------===//
1465// Methods for BugReporter and subclasses.
1466//===----------------------------------------------------------------------===//
1467
1468BugReportEquivClass::~BugReportEquivClass() {
1469  for (iterator I=begin(), E=end(); I!=E; ++I) delete *I;
1470}
1471
1472GRBugReporter::~GRBugReporter() { }
1473BugReporterData::~BugReporterData() {}
1474
1475ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); }
1476
1477ProgramStateManager&
1478GRBugReporter::getStateManager() { return Eng.getStateManager(); }
1479
1480BugReporter::~BugReporter() {
1481  FlushReports();
1482
1483  // Free the bug reports we are tracking.
1484  typedef std::vector<BugReportEquivClass *> ContTy;
1485  for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end();
1486       I != E; ++I) {
1487    delete *I;
1488  }
1489}
1490
1491void BugReporter::FlushReports() {
1492  if (BugTypes.isEmpty())
1493    return;
1494
1495  // First flush the warnings for each BugType.  This may end up creating new
1496  // warnings and new BugTypes.
1497  // FIXME: Only NSErrorChecker needs BugType's FlushReports.
1498  // Turn NSErrorChecker into a proper checker and remove this.
1499  SmallVector<const BugType*, 16> bugTypes;
1500  for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I)
1501    bugTypes.push_back(*I);
1502  for (SmallVector<const BugType*, 16>::iterator
1503         I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I)
1504    const_cast<BugType*>(*I)->FlushReports(*this);
1505
1506  typedef llvm::FoldingSet<BugReportEquivClass> SetTy;
1507  for (SetTy::iterator EI=EQClasses.begin(), EE=EQClasses.end(); EI!=EE;++EI){
1508    BugReportEquivClass& EQ = *EI;
1509    FlushReport(EQ);
1510  }
1511
1512  // BugReporter owns and deletes only BugTypes created implicitly through
1513  // EmitBasicReport.
1514  // FIXME: There are leaks from checkers that assume that the BugTypes they
1515  // create will be destroyed by the BugReporter.
1516  for (llvm::StringMap<BugType*>::iterator
1517         I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I)
1518    delete I->second;
1519
1520  // Remove all references to the BugType objects.
1521  BugTypes = F.getEmptySet();
1522}
1523
1524//===----------------------------------------------------------------------===//
1525// PathDiagnostics generation.
1526//===----------------------------------------------------------------------===//
1527
1528static std::pair<std::pair<ExplodedGraph*, NodeBackMap*>,
1529                 std::pair<ExplodedNode*, unsigned> >
1530MakeReportGraph(const ExplodedGraph* G,
1531                SmallVectorImpl<const ExplodedNode*> &nodes) {
1532
1533  // Create the trimmed graph.  It will contain the shortest paths from the
1534  // error nodes to the root.  In the new graph we should only have one
1535  // error node unless there are two or more error nodes with the same minimum
1536  // path length.
1537  ExplodedGraph* GTrim;
1538  InterExplodedGraphMap* NMap;
1539
1540  llvm::DenseMap<const void*, const void*> InverseMap;
1541  llvm::tie(GTrim, NMap) = G->Trim(nodes.data(), nodes.data() + nodes.size(),
1542                                   &InverseMap);
1543
1544  // Create owning pointers for GTrim and NMap just to ensure that they are
1545  // released when this function exists.
1546  OwningPtr<ExplodedGraph> AutoReleaseGTrim(GTrim);
1547  OwningPtr<InterExplodedGraphMap> AutoReleaseNMap(NMap);
1548
1549  // Find the (first) error node in the trimmed graph.  We just need to consult
1550  // the node map (NMap) which maps from nodes in the original graph to nodes
1551  // in the new graph.
1552
1553  std::queue<const ExplodedNode*> WS;
1554  typedef llvm::DenseMap<const ExplodedNode*, unsigned> IndexMapTy;
1555  IndexMapTy IndexMap;
1556
1557  for (unsigned nodeIndex = 0 ; nodeIndex < nodes.size(); ++nodeIndex) {
1558    const ExplodedNode *originalNode = nodes[nodeIndex];
1559    if (const ExplodedNode *N = NMap->getMappedNode(originalNode)) {
1560      WS.push(N);
1561      IndexMap[originalNode] = nodeIndex;
1562    }
1563  }
1564
1565  assert(!WS.empty() && "No error node found in the trimmed graph.");
1566
1567  // Create a new (third!) graph with a single path.  This is the graph
1568  // that will be returned to the caller.
1569  ExplodedGraph *GNew = new ExplodedGraph();
1570
1571  // Sometimes the trimmed graph can contain a cycle.  Perform a reverse BFS
1572  // to the root node, and then construct a new graph that contains only
1573  // a single path.
1574  llvm::DenseMap<const void*,unsigned> Visited;
1575
1576  unsigned cnt = 0;
1577  const ExplodedNode *Root = 0;
1578
1579  while (!WS.empty()) {
1580    const ExplodedNode *Node = WS.front();
1581    WS.pop();
1582
1583    if (Visited.find(Node) != Visited.end())
1584      continue;
1585
1586    Visited[Node] = cnt++;
1587
1588    if (Node->pred_empty()) {
1589      Root = Node;
1590      break;
1591    }
1592
1593    for (ExplodedNode::const_pred_iterator I=Node->pred_begin(),
1594         E=Node->pred_end(); I!=E; ++I)
1595      WS.push(*I);
1596  }
1597
1598  assert(Root);
1599
1600  // Now walk from the root down the BFS path, always taking the successor
1601  // with the lowest number.
1602  ExplodedNode *Last = 0, *First = 0;
1603  NodeBackMap *BM = new NodeBackMap();
1604  unsigned NodeIndex = 0;
1605
1606  for ( const ExplodedNode *N = Root ;;) {
1607    // Lookup the number associated with the current node.
1608    llvm::DenseMap<const void*,unsigned>::iterator I = Visited.find(N);
1609    assert(I != Visited.end());
1610
1611    // Create the equivalent node in the new graph with the same state
1612    // and location.
1613    ExplodedNode *NewN = GNew->getNode(N->getLocation(), N->getState());
1614
1615    // Store the mapping to the original node.
1616    llvm::DenseMap<const void*, const void*>::iterator IMitr=InverseMap.find(N);
1617    assert(IMitr != InverseMap.end() && "No mapping to original node.");
1618    (*BM)[NewN] = (const ExplodedNode*) IMitr->second;
1619
1620    // Link up the new node with the previous node.
1621    if (Last)
1622      NewN->addPredecessor(Last, *GNew);
1623
1624    Last = NewN;
1625
1626    // Are we at the final node?
1627    IndexMapTy::iterator IMI =
1628      IndexMap.find((const ExplodedNode*)(IMitr->second));
1629    if (IMI != IndexMap.end()) {
1630      First = NewN;
1631      NodeIndex = IMI->second;
1632      break;
1633    }
1634
1635    // Find the next successor node.  We choose the node that is marked
1636    // with the lowest DFS number.
1637    ExplodedNode::const_succ_iterator SI = N->succ_begin();
1638    ExplodedNode::const_succ_iterator SE = N->succ_end();
1639    N = 0;
1640
1641    for (unsigned MinVal = 0; SI != SE; ++SI) {
1642
1643      I = Visited.find(*SI);
1644
1645      if (I == Visited.end())
1646        continue;
1647
1648      if (!N || I->second < MinVal) {
1649        N = *SI;
1650        MinVal = I->second;
1651      }
1652    }
1653
1654    assert(N);
1655  }
1656
1657  assert(First);
1658
1659  return std::make_pair(std::make_pair(GNew, BM),
1660                        std::make_pair(First, NodeIndex));
1661}
1662
1663/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object
1664///  and collapses PathDiagosticPieces that are expanded by macros.
1665static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) {
1666  typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>,
1667                                SourceLocation> > MacroStackTy;
1668
1669  typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> >
1670          PiecesTy;
1671
1672  MacroStackTy MacroStack;
1673  PiecesTy Pieces;
1674
1675  for (PathPieces::const_iterator I = path.begin(), E = path.end();
1676       I!=E; ++I) {
1677
1678    PathDiagnosticPiece *piece = I->getPtr();
1679
1680    // Recursively compact calls.
1681    if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){
1682      CompactPathDiagnostic(call->path, SM);
1683    }
1684
1685    // Get the location of the PathDiagnosticPiece.
1686    const FullSourceLoc Loc = piece->getLocation().asLocation();
1687
1688    // Determine the instantiation location, which is the location we group
1689    // related PathDiagnosticPieces.
1690    SourceLocation InstantiationLoc = Loc.isMacroID() ?
1691                                      SM.getExpansionLoc(Loc) :
1692                                      SourceLocation();
1693
1694    if (Loc.isFileID()) {
1695      MacroStack.clear();
1696      Pieces.push_back(piece);
1697      continue;
1698    }
1699
1700    assert(Loc.isMacroID());
1701
1702    // Is the PathDiagnosticPiece within the same macro group?
1703    if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
1704      MacroStack.back().first->subPieces.push_back(piece);
1705      continue;
1706    }
1707
1708    // We aren't in the same group.  Are we descending into a new macro
1709    // or are part of an old one?
1710    IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup;
1711
1712    SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
1713                                          SM.getExpansionLoc(Loc) :
1714                                          SourceLocation();
1715
1716    // Walk the entire macro stack.
1717    while (!MacroStack.empty()) {
1718      if (InstantiationLoc == MacroStack.back().second) {
1719        MacroGroup = MacroStack.back().first;
1720        break;
1721      }
1722
1723      if (ParentInstantiationLoc == MacroStack.back().second) {
1724        MacroGroup = MacroStack.back().first;
1725        break;
1726      }
1727
1728      MacroStack.pop_back();
1729    }
1730
1731    if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) {
1732      // Create a new macro group and add it to the stack.
1733      PathDiagnosticMacroPiece *NewGroup =
1734        new PathDiagnosticMacroPiece(
1735          PathDiagnosticLocation::createSingleLocation(piece->getLocation()));
1736
1737      if (MacroGroup)
1738        MacroGroup->subPieces.push_back(NewGroup);
1739      else {
1740        assert(InstantiationLoc.isFileID());
1741        Pieces.push_back(NewGroup);
1742      }
1743
1744      MacroGroup = NewGroup;
1745      MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc));
1746    }
1747
1748    // Finally, add the PathDiagnosticPiece to the group.
1749    MacroGroup->subPieces.push_back(piece);
1750  }
1751
1752  // Now take the pieces and construct a new PathDiagnostic.
1753  path.clear();
1754
1755  for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I)
1756    path.push_back(*I);
1757}
1758
1759void GRBugReporter::GeneratePathDiagnostic(PathDiagnostic& PD,
1760                        SmallVectorImpl<BugReport *> &bugReports) {
1761
1762  assert(!bugReports.empty());
1763  SmallVector<const ExplodedNode *, 10> errorNodes;
1764  for (SmallVectorImpl<BugReport*>::iterator I = bugReports.begin(),
1765    E = bugReports.end(); I != E; ++I) {
1766      errorNodes.push_back((*I)->getErrorNode());
1767  }
1768
1769  // Construct a new graph that contains only a single path from the error
1770  // node to a root.
1771  const std::pair<std::pair<ExplodedGraph*, NodeBackMap*>,
1772  std::pair<ExplodedNode*, unsigned> >&
1773    GPair = MakeReportGraph(&getGraph(), errorNodes);
1774
1775  // Find the BugReport with the original location.
1776  assert(GPair.second.second < bugReports.size());
1777  BugReport *R = bugReports[GPair.second.second];
1778  assert(R && "No original report found for sliced graph.");
1779
1780  OwningPtr<ExplodedGraph> ReportGraph(GPair.first.first);
1781  OwningPtr<NodeBackMap> BackMap(GPair.first.second);
1782  const ExplodedNode *N = GPair.second.first;
1783
1784  // Start building the path diagnostic...
1785  PathDiagnosticBuilder PDB(*this, R, BackMap.get(),
1786                            getPathDiagnosticConsumer());
1787
1788  // Register additional node visitors.
1789  R->addVisitor(new NilReceiverBRVisitor());
1790  R->addVisitor(new ConditionBRVisitor());
1791
1792  // Generate the very last diagnostic piece - the piece is visible before
1793  // the trace is expanded.
1794  PathDiagnosticPiece *LastPiece = 0;
1795  for (BugReport::visitor_iterator I = R->visitor_begin(),
1796                                   E = R->visitor_end(); I!=E; ++I) {
1797    if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) {
1798      assert (!LastPiece &&
1799              "There can only be one final piece in a diagnostic.");
1800      LastPiece = Piece;
1801    }
1802  }
1803  if (!LastPiece)
1804    LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R);
1805  if (LastPiece)
1806    PD.getActivePath().push_back(LastPiece);
1807  else
1808    return;
1809
1810  switch (PDB.getGenerationScheme()) {
1811    case PathDiagnosticConsumer::Extensive:
1812      GenerateExtensivePathDiagnostic(PD, PDB, N);
1813      break;
1814    case PathDiagnosticConsumer::Minimal:
1815      GenerateMinimalPathDiagnostic(PD, PDB, N);
1816      break;
1817  }
1818
1819  // Finally, prune the diagnostic path of uninteresting stuff.
1820  bool hasSomethingInteresting = RemoveUneededCalls(PD.getMutablePieces());
1821  assert(hasSomethingInteresting);
1822  (void) hasSomethingInteresting;
1823}
1824
1825void BugReporter::Register(BugType *BT) {
1826  BugTypes = F.add(BugTypes, BT);
1827}
1828
1829void BugReporter::EmitReport(BugReport* R) {
1830  // Compute the bug report's hash to determine its equivalence class.
1831  llvm::FoldingSetNodeID ID;
1832  R->Profile(ID);
1833
1834  // Lookup the equivance class.  If there isn't one, create it.
1835  BugType& BT = R->getBugType();
1836  Register(&BT);
1837  void *InsertPos;
1838  BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
1839
1840  if (!EQ) {
1841    EQ = new BugReportEquivClass(R);
1842    EQClasses.InsertNode(EQ, InsertPos);
1843    EQClassesVector.push_back(EQ);
1844  }
1845  else
1846    EQ->AddReport(R);
1847}
1848
1849
1850//===----------------------------------------------------------------------===//
1851// Emitting reports in equivalence classes.
1852//===----------------------------------------------------------------------===//
1853
1854namespace {
1855struct FRIEC_WLItem {
1856  const ExplodedNode *N;
1857  ExplodedNode::const_succ_iterator I, E;
1858
1859  FRIEC_WLItem(const ExplodedNode *n)
1860  : N(n), I(N->succ_begin()), E(N->succ_end()) {}
1861};
1862}
1863
1864static BugReport *
1865FindReportInEquivalenceClass(BugReportEquivClass& EQ,
1866                             SmallVectorImpl<BugReport*> &bugReports) {
1867
1868  BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end();
1869  assert(I != E);
1870  BugReport *R = *I;
1871  BugType& BT = R->getBugType();
1872
1873  // If we don't need to suppress any of the nodes because they are
1874  // post-dominated by a sink, simply add all the nodes in the equivalence class
1875  // to 'Nodes'.  Any of the reports will serve as a "representative" report.
1876  if (!BT.isSuppressOnSink()) {
1877    for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) {
1878      const ExplodedNode *N = I->getErrorNode();
1879      if (N) {
1880        R = *I;
1881        bugReports.push_back(R);
1882      }
1883    }
1884    return R;
1885  }
1886
1887  // For bug reports that should be suppressed when all paths are post-dominated
1888  // by a sink node, iterate through the reports in the equivalence class
1889  // until we find one that isn't post-dominated (if one exists).  We use a
1890  // DFS traversal of the ExplodedGraph to find a non-sink node.  We could write
1891  // this as a recursive function, but we don't want to risk blowing out the
1892  // stack for very long paths.
1893  BugReport *exampleReport = 0;
1894
1895  for (; I != E; ++I) {
1896    R = *I;
1897    const ExplodedNode *errorNode = R->getErrorNode();
1898
1899    if (!errorNode)
1900      continue;
1901    if (errorNode->isSink()) {
1902      llvm_unreachable(
1903           "BugType::isSuppressSink() should not be 'true' for sink end nodes");
1904    }
1905    // No successors?  By definition this nodes isn't post-dominated by a sink.
1906    if (errorNode->succ_empty()) {
1907      bugReports.push_back(R);
1908      if (!exampleReport)
1909        exampleReport = R;
1910      continue;
1911    }
1912
1913    // At this point we know that 'N' is not a sink and it has at least one
1914    // successor.  Use a DFS worklist to find a non-sink end-of-path node.
1915    typedef FRIEC_WLItem WLItem;
1916    typedef SmallVector<WLItem, 10> DFSWorkList;
1917    llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
1918
1919    DFSWorkList WL;
1920    WL.push_back(errorNode);
1921    Visited[errorNode] = 1;
1922
1923    while (!WL.empty()) {
1924      WLItem &WI = WL.back();
1925      assert(!WI.N->succ_empty());
1926
1927      for (; WI.I != WI.E; ++WI.I) {
1928        const ExplodedNode *Succ = *WI.I;
1929        // End-of-path node?
1930        if (Succ->succ_empty()) {
1931          // If we found an end-of-path node that is not a sink.
1932          if (!Succ->isSink()) {
1933            bugReports.push_back(R);
1934            if (!exampleReport)
1935              exampleReport = R;
1936            WL.clear();
1937            break;
1938          }
1939          // Found a sink?  Continue on to the next successor.
1940          continue;
1941        }
1942        // Mark the successor as visited.  If it hasn't been explored,
1943        // enqueue it to the DFS worklist.
1944        unsigned &mark = Visited[Succ];
1945        if (!mark) {
1946          mark = 1;
1947          WL.push_back(Succ);
1948          break;
1949        }
1950      }
1951
1952      // The worklist may have been cleared at this point.  First
1953      // check if it is empty before checking the last item.
1954      if (!WL.empty() && &WL.back() == &WI)
1955        WL.pop_back();
1956    }
1957  }
1958
1959  // ExampleReport will be NULL if all the nodes in the equivalence class
1960  // were post-dominated by sinks.
1961  return exampleReport;
1962}
1963
1964//===----------------------------------------------------------------------===//
1965// DiagnosticCache.  This is a hack to cache analyzer diagnostics.  It
1966// uses global state, which eventually should go elsewhere.
1967//===----------------------------------------------------------------------===//
1968namespace {
1969class DiagCacheItem : public llvm::FoldingSetNode {
1970  llvm::FoldingSetNodeID ID;
1971public:
1972  DiagCacheItem(BugReport *R, PathDiagnostic *PD) {
1973    R->Profile(ID);
1974    PD->Profile(ID);
1975  }
1976
1977  void Profile(llvm::FoldingSetNodeID &id) {
1978    id = ID;
1979  }
1980
1981  llvm::FoldingSetNodeID &getID() { return ID; }
1982};
1983}
1984
1985static bool IsCachedDiagnostic(BugReport *R, PathDiagnostic *PD) {
1986  // FIXME: Eventually this diagnostic cache should reside in something
1987  // like AnalysisManager instead of being a static variable.  This is
1988  // really unsafe in the long term.
1989  typedef llvm::FoldingSet<DiagCacheItem> DiagnosticCache;
1990  static DiagnosticCache DC;
1991
1992  void *InsertPos;
1993  DiagCacheItem *Item = new DiagCacheItem(R, PD);
1994
1995  if (DC.FindNodeOrInsertPos(Item->getID(), InsertPos)) {
1996    delete Item;
1997    return true;
1998  }
1999
2000  DC.InsertNode(Item, InsertPos);
2001  return false;
2002}
2003
2004void BugReporter::FlushReport(BugReportEquivClass& EQ) {
2005  SmallVector<BugReport*, 10> bugReports;
2006  BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports);
2007  if (!exampleReport)
2008    return;
2009
2010  PathDiagnosticConsumer* PD = getPathDiagnosticConsumer();
2011
2012  // FIXME: Make sure we use the 'R' for the path that was actually used.
2013  // Probably doesn't make a difference in practice.
2014  BugType& BT = exampleReport->getBugType();
2015
2016  OwningPtr<PathDiagnostic>
2017    D(new PathDiagnostic(exampleReport->getBugType().getName(),
2018                         !PD || PD->useVerboseDescription()
2019                         ? exampleReport->getDescription()
2020                         : exampleReport->getShortDescription(),
2021                         BT.getCategory()));
2022
2023  if (!bugReports.empty())
2024    GeneratePathDiagnostic(*D.get(), bugReports);
2025
2026  if (IsCachedDiagnostic(exampleReport, D.get()))
2027    return;
2028
2029  // Get the meta data.
2030  const BugReport::ExtraTextList &Meta =
2031                                  exampleReport->getExtraText();
2032  for (BugReport::ExtraTextList::const_iterator i = Meta.begin(),
2033                                                e = Meta.end(); i != e; ++i) {
2034    D->addMeta(*i);
2035  }
2036
2037  // Emit a summary diagnostic to the regular Diagnostics engine.
2038  BugReport::ranges_iterator Beg, End;
2039  llvm::tie(Beg, End) = exampleReport->getRanges();
2040  DiagnosticsEngine &Diag = getDiagnostic();
2041
2042  // Search the description for '%', as that will be interpretted as a
2043  // format character by FormatDiagnostics.
2044  StringRef desc = exampleReport->getShortDescription();
2045  unsigned ErrorDiag;
2046  {
2047    SmallString<512> TmpStr;
2048    llvm::raw_svector_ostream Out(TmpStr);
2049    for (StringRef::iterator I=desc.begin(), E=desc.end(); I!=E; ++I)
2050      if (*I == '%')
2051        Out << "%%";
2052      else
2053        Out << *I;
2054
2055    Out.flush();
2056    ErrorDiag = Diag.getCustomDiagID(DiagnosticsEngine::Warning, TmpStr);
2057  }
2058
2059  {
2060    DiagnosticBuilder diagBuilder = Diag.Report(
2061      exampleReport->getLocation(getSourceManager()).asLocation(), ErrorDiag);
2062    for (BugReport::ranges_iterator I = Beg; I != End; ++I)
2063      diagBuilder << *I;
2064  }
2065
2066  // Emit a full diagnostic for the path if we have a PathDiagnosticConsumer.
2067  if (!PD)
2068    return;
2069
2070  if (D->path.empty()) {
2071    PathDiagnosticPiece *piece = new PathDiagnosticEventPiece(
2072                                 exampleReport->getLocation(getSourceManager()),
2073                                 exampleReport->getDescription());
2074
2075    for ( ; Beg != End; ++Beg) piece->addRange(*Beg);
2076    D->getActivePath().push_back(piece);
2077  }
2078
2079  PD->HandlePathDiagnostic(D.take());
2080}
2081
2082void BugReporter::EmitBasicReport(StringRef name, StringRef str,
2083                                  PathDiagnosticLocation Loc,
2084                                  SourceRange* RBeg, unsigned NumRanges) {
2085  EmitBasicReport(name, "", str, Loc, RBeg, NumRanges);
2086}
2087
2088void BugReporter::EmitBasicReport(StringRef name,
2089                                  StringRef category,
2090                                  StringRef str, PathDiagnosticLocation Loc,
2091                                  SourceRange* RBeg, unsigned NumRanges) {
2092
2093  // 'BT' is owned by BugReporter.
2094  BugType *BT = getBugTypeForName(name, category);
2095  BugReport *R = new BugReport(*BT, str, Loc);
2096  for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg);
2097  EmitReport(R);
2098}
2099
2100BugType *BugReporter::getBugTypeForName(StringRef name,
2101                                        StringRef category) {
2102  SmallString<136> fullDesc;
2103  llvm::raw_svector_ostream(fullDesc) << name << ":" << category;
2104  llvm::StringMapEntry<BugType *> &
2105      entry = StrBugTypes.GetOrCreateValue(fullDesc);
2106  BugType *BT = entry.getValue();
2107  if (!BT) {
2108    BT = new BugType(name, category);
2109    entry.setValue(BT);
2110  }
2111  return BT;
2112}
2113