xref: /freebsd/contrib/llvm-project/clang/lib/Analysis/PathDiagnostic.cpp (revision bfed2417f472f87e720b37bdac9ffd75ca2abc54) 
1 //===- PathDiagnostic.cpp - Path-Specific Diagnostic Handling -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file defines the PathDiagnostic-related interfaces.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Analysis/PathDiagnostic.h"
14 #include "clang/AST/Decl.h"
15 #include "clang/AST/DeclBase.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/DeclTemplate.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/OperationKinds.h"
22 #include "clang/AST/ParentMap.h"
23 #include "clang/AST/PrettyPrinter.h"
24 #include "clang/AST/Stmt.h"
25 #include "clang/AST/Type.h"
26 #include "clang/Analysis/AnalysisDeclContext.h"
27 #include "clang/Analysis/CFG.h"
28 #include "clang/Analysis/ProgramPoint.h"
29 #include "clang/Basic/FileManager.h"
30 #include "clang/Basic/LLVM.h"
31 #include "clang/Basic/SourceLocation.h"
32 #include "clang/Basic/SourceManager.h"
33 #include "llvm/ADT/ArrayRef.h"
34 #include "llvm/ADT/FoldingSet.h"
35 #include "llvm/ADT/STLExtras.h"
36 #include "llvm/ADT/SmallString.h"
37 #include "llvm/ADT/SmallVector.h"
38 #include "llvm/ADT/StringExtras.h"
39 #include "llvm/ADT/StringRef.h"
40 #include "llvm/Support/Casting.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include <cassert>
44 #include <cstring>
45 #include <memory>
46 #include <optional>
47 #include <utility>
48 #include <vector>
49 
50 using namespace clang;
51 using namespace ento;
52 
53 static StringRef StripTrailingDots(StringRef s) {
54   for (StringRef::size_type i = s.size(); i != 0; --i)
55     if (s[i - 1] != '.')
56       return s.substr(0, i);
57   return {};
58 }
59 
60 PathDiagnosticPiece::PathDiagnosticPiece(StringRef s,
61                                          Kind k, DisplayHint hint)
62     : str(StripTrailingDots(s)), kind(k), Hint(hint) {}
63 
64 PathDiagnosticPiece::PathDiagnosticPiece(Kind k, DisplayHint hint)
65     : kind(k), Hint(hint) {}
66 
67 PathDiagnosticPiece::~PathDiagnosticPiece() = default;
68 
69 PathDiagnosticEventPiece::~PathDiagnosticEventPiece() = default;
70 
71 PathDiagnosticCallPiece::~PathDiagnosticCallPiece() = default;
72 
73 PathDiagnosticControlFlowPiece::~PathDiagnosticControlFlowPiece() = default;
74 
75 PathDiagnosticMacroPiece::~PathDiagnosticMacroPiece() = default;
76 
77 PathDiagnosticNotePiece::~PathDiagnosticNotePiece() = default;
78 
79 PathDiagnosticPopUpPiece::~PathDiagnosticPopUpPiece() = default;
80 
81 void PathPieces::flattenTo(PathPieces &Primary, PathPieces &Current,
82                            bool ShouldFlattenMacros) const {
83   for (auto &Piece : *this) {
84     switch (Piece->getKind()) {
85     case PathDiagnosticPiece::Call: {
86       auto &Call = cast<PathDiagnosticCallPiece>(*Piece);
87       if (auto CallEnter = Call.getCallEnterEvent())
88         Current.push_back(std::move(CallEnter));
89       Call.path.flattenTo(Primary, Primary, ShouldFlattenMacros);
90       if (auto callExit = Call.getCallExitEvent())
91         Current.push_back(std::move(callExit));
92       break;
93     }
94     case PathDiagnosticPiece::Macro: {
95       auto &Macro = cast<PathDiagnosticMacroPiece>(*Piece);
96       if (ShouldFlattenMacros) {
97         Macro.subPieces.flattenTo(Primary, Primary, ShouldFlattenMacros);
98       } else {
99         Current.push_back(Piece);
100         PathPieces NewPath;
101         Macro.subPieces.flattenTo(Primary, NewPath, ShouldFlattenMacros);
102         // FIXME: This probably shouldn't mutate the original path piece.
103         Macro.subPieces = NewPath;
104       }
105       break;
106     }
107     case PathDiagnosticPiece::Event:
108     case PathDiagnosticPiece::ControlFlow:
109     case PathDiagnosticPiece::Note:
110     case PathDiagnosticPiece::PopUp:
111       Current.push_back(Piece);
112       break;
113     }
114   }
115 }
116 
117 PathDiagnostic::~PathDiagnostic() = default;
118 
119 PathDiagnostic::PathDiagnostic(
120     StringRef CheckerName, const Decl *declWithIssue, StringRef bugtype,
121     StringRef verboseDesc, StringRef shortDesc, StringRef category,
122     PathDiagnosticLocation LocationToUnique, const Decl *DeclToUnique,
123     std::unique_ptr<FilesToLineNumsMap> ExecutedLines)
124     : CheckerName(CheckerName), DeclWithIssue(declWithIssue),
125       BugType(StripTrailingDots(bugtype)),
126       VerboseDesc(StripTrailingDots(verboseDesc)),
127       ShortDesc(StripTrailingDots(shortDesc)),
128       Category(StripTrailingDots(category)), UniqueingLoc(LocationToUnique),
129       UniqueingDecl(DeclToUnique), ExecutedLines(std::move(ExecutedLines)),
130       path(pathImpl) {}
131 
132 void PathDiagnosticConsumer::anchor() {}
133 
134 PathDiagnosticConsumer::~PathDiagnosticConsumer() {
135   // Delete the contents of the FoldingSet if it isn't empty already.
136   for (auto &Diag : Diags)
137     delete &Diag;
138 }
139 
140 void PathDiagnosticConsumer::HandlePathDiagnostic(
141     std::unique_ptr<PathDiagnostic> D) {
142   if (!D || D->path.empty())
143     return;
144 
145   // We need to flatten the locations (convert Stmt* to locations) because
146   // the referenced statements may be freed by the time the diagnostics
147   // are emitted.
148   D->flattenLocations();
149 
150   // If the PathDiagnosticConsumer does not support diagnostics that
151   // cross file boundaries, prune out such diagnostics now.
152   if (!supportsCrossFileDiagnostics()) {
153     // Verify that the entire path is from the same FileID.
154     FileID FID;
155     const SourceManager &SMgr = D->path.front()->getLocation().getManager();
156     SmallVector<const PathPieces *, 5> WorkList;
157     WorkList.push_back(&D->path);
158     SmallString<128> buf;
159     llvm::raw_svector_ostream warning(buf);
160     warning << "warning: Path diagnostic report is not generated. Current "
161             << "output format does not support diagnostics that cross file "
162             << "boundaries. Refer to --analyzer-output for valid output "
163             << "formats\n";
164 
165     while (!WorkList.empty()) {
166       const PathPieces &path = *WorkList.pop_back_val();
167 
168       for (const auto &I : path) {
169         const PathDiagnosticPiece *piece = I.get();
170         FullSourceLoc L = piece->getLocation().asLocation().getExpansionLoc();
171 
172         if (FID.isInvalid()) {
173           FID = SMgr.getFileID(L);
174         } else if (SMgr.getFileID(L) != FID) {
175           llvm::errs() << warning.str();
176           return;
177         }
178 
179         // Check the source ranges.
180         ArrayRef<SourceRange> Ranges = piece->getRanges();
181         for (const auto &I : Ranges) {
182           SourceLocation L = SMgr.getExpansionLoc(I.getBegin());
183           if (!L.isFileID() || SMgr.getFileID(L) != FID) {
184             llvm::errs() << warning.str();
185             return;
186           }
187           L = SMgr.getExpansionLoc(I.getEnd());
188           if (!L.isFileID() || SMgr.getFileID(L) != FID) {
189             llvm::errs() << warning.str();
190             return;
191           }
192         }
193 
194         if (const auto *call = dyn_cast<PathDiagnosticCallPiece>(piece))
195           WorkList.push_back(&call->path);
196         else if (const auto *macro = dyn_cast<PathDiagnosticMacroPiece>(piece))
197           WorkList.push_back(&macro->subPieces);
198       }
199     }
200 
201     if (FID.isInvalid())
202       return; // FIXME: Emit a warning?
203   }
204 
205   // Profile the node to see if we already have something matching it
206   llvm::FoldingSetNodeID profile;
207   D->Profile(profile);
208   void *InsertPos = nullptr;
209 
210   if (PathDiagnostic *orig = Diags.FindNodeOrInsertPos(profile, InsertPos)) {
211     // Keep the PathDiagnostic with the shorter path.
212     // Note, the enclosing routine is called in deterministic order, so the
213     // results will be consistent between runs (no reason to break ties if the
214     // size is the same).
215     const unsigned orig_size = orig->full_size();
216     const unsigned new_size = D->full_size();
217     if (orig_size <= new_size)
218       return;
219 
220     assert(orig != D.get());
221     Diags.RemoveNode(orig);
222     delete orig;
223   }
224 
225   Diags.InsertNode(D.release());
226 }
227 
228 static std::optional<bool> comparePath(const PathPieces &X,
229                                        const PathPieces &Y);
230 
231 static std::optional<bool>
232 compareControlFlow(const PathDiagnosticControlFlowPiece &X,
233                    const PathDiagnosticControlFlowPiece &Y) {
234   FullSourceLoc XSL = X.getStartLocation().asLocation();
235   FullSourceLoc YSL = Y.getStartLocation().asLocation();
236   if (XSL != YSL)
237     return XSL.isBeforeInTranslationUnitThan(YSL);
238   FullSourceLoc XEL = X.getEndLocation().asLocation();
239   FullSourceLoc YEL = Y.getEndLocation().asLocation();
240   if (XEL != YEL)
241     return XEL.isBeforeInTranslationUnitThan(YEL);
242   return std::nullopt;
243 }
244 
245 static std::optional<bool> compareMacro(const PathDiagnosticMacroPiece &X,
246                                         const PathDiagnosticMacroPiece &Y) {
247   return comparePath(X.subPieces, Y.subPieces);
248 }
249 
250 static std::optional<bool> compareCall(const PathDiagnosticCallPiece &X,
251                                        const PathDiagnosticCallPiece &Y) {
252   FullSourceLoc X_CEL = X.callEnter.asLocation();
253   FullSourceLoc Y_CEL = Y.callEnter.asLocation();
254   if (X_CEL != Y_CEL)
255     return X_CEL.isBeforeInTranslationUnitThan(Y_CEL);
256   FullSourceLoc X_CEWL = X.callEnterWithin.asLocation();
257   FullSourceLoc Y_CEWL = Y.callEnterWithin.asLocation();
258   if (X_CEWL != Y_CEWL)
259     return X_CEWL.isBeforeInTranslationUnitThan(Y_CEWL);
260   FullSourceLoc X_CRL = X.callReturn.asLocation();
261   FullSourceLoc Y_CRL = Y.callReturn.asLocation();
262   if (X_CRL != Y_CRL)
263     return X_CRL.isBeforeInTranslationUnitThan(Y_CRL);
264   return comparePath(X.path, Y.path);
265 }
266 
267 static std::optional<bool> comparePiece(const PathDiagnosticPiece &X,
268                                         const PathDiagnosticPiece &Y) {
269   if (X.getKind() != Y.getKind())
270     return X.getKind() < Y.getKind();
271 
272   FullSourceLoc XL = X.getLocation().asLocation();
273   FullSourceLoc YL = Y.getLocation().asLocation();
274   if (XL != YL)
275     return XL.isBeforeInTranslationUnitThan(YL);
276 
277   if (X.getString() != Y.getString())
278     return X.getString() < Y.getString();
279 
280   if (X.getRanges().size() != Y.getRanges().size())
281     return X.getRanges().size() < Y.getRanges().size();
282 
283   const SourceManager &SM = XL.getManager();
284 
285   for (unsigned i = 0, n = X.getRanges().size(); i < n; ++i) {
286     SourceRange XR = X.getRanges()[i];
287     SourceRange YR = Y.getRanges()[i];
288     if (XR != YR) {
289       if (XR.getBegin() != YR.getBegin())
290         return SM.isBeforeInTranslationUnit(XR.getBegin(), YR.getBegin());
291       return SM.isBeforeInTranslationUnit(XR.getEnd(), YR.getEnd());
292     }
293   }
294 
295   switch (X.getKind()) {
296     case PathDiagnosticPiece::ControlFlow:
297       return compareControlFlow(cast<PathDiagnosticControlFlowPiece>(X),
298                                 cast<PathDiagnosticControlFlowPiece>(Y));
299     case PathDiagnosticPiece::Macro:
300       return compareMacro(cast<PathDiagnosticMacroPiece>(X),
301                           cast<PathDiagnosticMacroPiece>(Y));
302     case PathDiagnosticPiece::Call:
303       return compareCall(cast<PathDiagnosticCallPiece>(X),
304                          cast<PathDiagnosticCallPiece>(Y));
305     case PathDiagnosticPiece::Event:
306     case PathDiagnosticPiece::Note:
307     case PathDiagnosticPiece::PopUp:
308       return std::nullopt;
309   }
310   llvm_unreachable("all cases handled");
311 }
312 
313 static std::optional<bool> comparePath(const PathPieces &X,
314                                        const PathPieces &Y) {
315   if (X.size() != Y.size())
316     return X.size() < Y.size();
317 
318   PathPieces::const_iterator X_I = X.begin(), X_end = X.end();
319   PathPieces::const_iterator Y_I = Y.begin(), Y_end = Y.end();
320 
321   for (; X_I != X_end && Y_I != Y_end; ++X_I, ++Y_I)
322     if (std::optional<bool> b = comparePiece(**X_I, **Y_I))
323       return *b;
324 
325   return std::nullopt;
326 }
327 
328 static bool compareCrossTUSourceLocs(FullSourceLoc XL, FullSourceLoc YL) {
329   if (XL.isInvalid() && YL.isValid())
330     return true;
331   if (XL.isValid() && YL.isInvalid())
332     return false;
333   std::pair<FileID, unsigned> XOffs = XL.getDecomposedLoc();
334   std::pair<FileID, unsigned> YOffs = YL.getDecomposedLoc();
335   const SourceManager &SM = XL.getManager();
336   std::pair<bool, bool> InSameTU = SM.isInTheSameTranslationUnit(XOffs, YOffs);
337   if (InSameTU.first)
338     return XL.isBeforeInTranslationUnitThan(YL);
339   const FileEntry *XFE = SM.getFileEntryForID(XL.getSpellingLoc().getFileID());
340   const FileEntry *YFE = SM.getFileEntryForID(YL.getSpellingLoc().getFileID());
341   if (!XFE || !YFE)
342     return XFE && !YFE;
343   int NameCmp = XFE->getName().compare(YFE->getName());
344   if (NameCmp != 0)
345     return NameCmp < 0;
346   // Last resort: Compare raw file IDs that are possibly expansions.
347   return XL.getFileID() < YL.getFileID();
348 }
349 
350 static bool compare(const PathDiagnostic &X, const PathDiagnostic &Y) {
351   FullSourceLoc XL = X.getLocation().asLocation();
352   FullSourceLoc YL = Y.getLocation().asLocation();
353   if (XL != YL)
354     return compareCrossTUSourceLocs(XL, YL);
355   FullSourceLoc XUL = X.getUniqueingLoc().asLocation();
356   FullSourceLoc YUL = Y.getUniqueingLoc().asLocation();
357   if (XUL != YUL)
358     return compareCrossTUSourceLocs(XUL, YUL);
359   if (X.getBugType() != Y.getBugType())
360     return X.getBugType() < Y.getBugType();
361   if (X.getCategory() != Y.getCategory())
362     return X.getCategory() < Y.getCategory();
363   if (X.getVerboseDescription() != Y.getVerboseDescription())
364     return X.getVerboseDescription() < Y.getVerboseDescription();
365   if (X.getShortDescription() != Y.getShortDescription())
366     return X.getShortDescription() < Y.getShortDescription();
367   auto CompareDecls = [&XL](const Decl *D1,
368                             const Decl *D2) -> std::optional<bool> {
369     if (D1 == D2)
370       return std::nullopt;
371     if (!D1)
372       return true;
373     if (!D2)
374       return false;
375     SourceLocation D1L = D1->getLocation();
376     SourceLocation D2L = D2->getLocation();
377     if (D1L != D2L) {
378       const SourceManager &SM = XL.getManager();
379       return compareCrossTUSourceLocs(FullSourceLoc(D1L, SM),
380                                       FullSourceLoc(D2L, SM));
381     }
382     return std::nullopt;
383   };
384   if (auto Result = CompareDecls(X.getDeclWithIssue(), Y.getDeclWithIssue()))
385     return *Result;
386   if (XUL.isValid()) {
387     if (auto Result = CompareDecls(X.getUniqueingDecl(), Y.getUniqueingDecl()))
388       return *Result;
389   }
390   PathDiagnostic::meta_iterator XI = X.meta_begin(), XE = X.meta_end();
391   PathDiagnostic::meta_iterator YI = Y.meta_begin(), YE = Y.meta_end();
392   if (XE - XI != YE - YI)
393     return (XE - XI) < (YE - YI);
394   for ( ; XI != XE ; ++XI, ++YI) {
395     if (*XI != *YI)
396       return (*XI) < (*YI);
397   }
398   return *comparePath(X.path, Y.path);
399 }
400 
401 void PathDiagnosticConsumer::FlushDiagnostics(
402                                      PathDiagnosticConsumer::FilesMade *Files) {
403   if (flushed)
404     return;
405 
406   flushed = true;
407 
408   std::vector<const PathDiagnostic *> BatchDiags;
409   for (const auto &D : Diags)
410     BatchDiags.push_back(&D);
411 
412   // Sort the diagnostics so that they are always emitted in a deterministic
413   // order.
414   int (*Comp)(const PathDiagnostic *const *, const PathDiagnostic *const *) =
415       [](const PathDiagnostic *const *X, const PathDiagnostic *const *Y) {
416         assert(*X != *Y && "PathDiagnostics not uniqued!");
417         if (compare(**X, **Y))
418           return -1;
419         assert(compare(**Y, **X) && "Not a total order!");
420         return 1;
421       };
422   array_pod_sort(BatchDiags.begin(), BatchDiags.end(), Comp);
423 
424   FlushDiagnosticsImpl(BatchDiags, Files);
425 
426   // Delete the flushed diagnostics.
427   for (const auto D : BatchDiags)
428     delete D;
429 
430   // Clear out the FoldingSet.
431   Diags.clear();
432 }
433 
434 PathDiagnosticConsumer::FilesMade::~FilesMade() {
435   for (auto It = Set.begin(); It != Set.end();)
436     (It++)->~PDFileEntry();
437 }
438 
439 void PathDiagnosticConsumer::FilesMade::addDiagnostic(const PathDiagnostic &PD,
440                                                       StringRef ConsumerName,
441                                                       StringRef FileName) {
442   llvm::FoldingSetNodeID NodeID;
443   NodeID.Add(PD);
444   void *InsertPos;
445   PDFileEntry *Entry = Set.FindNodeOrInsertPos(NodeID, InsertPos);
446   if (!Entry) {
447     Entry = Alloc.Allocate<PDFileEntry>();
448     Entry = new (Entry) PDFileEntry(NodeID);
449     Set.InsertNode(Entry, InsertPos);
450   }
451 
452   // Allocate persistent storage for the file name.
453   char *FileName_cstr = (char*) Alloc.Allocate(FileName.size(), 1);
454   memcpy(FileName_cstr, FileName.data(), FileName.size());
455 
456   Entry->files.push_back(std::make_pair(ConsumerName,
457                                         StringRef(FileName_cstr,
458                                                   FileName.size())));
459 }
460 
461 PathDiagnosticConsumer::PDFileEntry::ConsumerFiles *
462 PathDiagnosticConsumer::FilesMade::getFiles(const PathDiagnostic &PD) {
463   llvm::FoldingSetNodeID NodeID;
464   NodeID.Add(PD);
465   void *InsertPos;
466   PDFileEntry *Entry = Set.FindNodeOrInsertPos(NodeID, InsertPos);
467   if (!Entry)
468     return nullptr;
469   return &Entry->files;
470 }
471 
472 //===----------------------------------------------------------------------===//
473 // PathDiagnosticLocation methods.
474 //===----------------------------------------------------------------------===//
475 
476 SourceLocation PathDiagnosticLocation::getValidSourceLocation(
477     const Stmt *S, LocationOrAnalysisDeclContext LAC, bool UseEndOfStatement) {
478   SourceLocation L = UseEndOfStatement ? S->getEndLoc() : S->getBeginLoc();
479   assert(!LAC.isNull() &&
480          "A valid LocationContext or AnalysisDeclContext should be passed to "
481          "PathDiagnosticLocation upon creation.");
482 
483   // S might be a temporary statement that does not have a location in the
484   // source code, so find an enclosing statement and use its location.
485   if (!L.isValid()) {
486     AnalysisDeclContext *ADC;
487     if (LAC.is<const LocationContext*>())
488       ADC = LAC.get<const LocationContext*>()->getAnalysisDeclContext();
489     else
490       ADC = LAC.get<AnalysisDeclContext*>();
491 
492     ParentMap &PM = ADC->getParentMap();
493 
494     const Stmt *Parent = S;
495     do {
496       Parent = PM.getParent(Parent);
497 
498       // In rare cases, we have implicit top-level expressions,
499       // such as arguments for implicit member initializers.
500       // In this case, fall back to the start of the body (even if we were
501       // asked for the statement end location).
502       if (!Parent) {
503         const Stmt *Body = ADC->getBody();
504         if (Body)
505           L = Body->getBeginLoc();
506         else
507           L = ADC->getDecl()->getEndLoc();
508         break;
509       }
510 
511       L = UseEndOfStatement ? Parent->getEndLoc() : Parent->getBeginLoc();
512     } while (!L.isValid());
513   }
514 
515   // FIXME: Ironically, this assert actually fails in some cases.
516   //assert(L.isValid());
517   return L;
518 }
519 
520 static PathDiagnosticLocation
521 getLocationForCaller(const StackFrameContext *SFC,
522                      const LocationContext *CallerCtx,
523                      const SourceManager &SM) {
524   const CFGBlock &Block = *SFC->getCallSiteBlock();
525   CFGElement Source = Block[SFC->getIndex()];
526 
527   switch (Source.getKind()) {
528   case CFGElement::Statement:
529   case CFGElement::Constructor:
530   case CFGElement::CXXRecordTypedCall:
531     return PathDiagnosticLocation(Source.castAs<CFGStmt>().getStmt(),
532                                   SM, CallerCtx);
533   case CFGElement::Initializer: {
534     const CFGInitializer &Init = Source.castAs<CFGInitializer>();
535     return PathDiagnosticLocation(Init.getInitializer()->getInit(),
536                                   SM, CallerCtx);
537   }
538   case CFGElement::AutomaticObjectDtor: {
539     const CFGAutomaticObjDtor &Dtor = Source.castAs<CFGAutomaticObjDtor>();
540     return PathDiagnosticLocation::createEnd(Dtor.getTriggerStmt(),
541                                              SM, CallerCtx);
542   }
543   case CFGElement::DeleteDtor: {
544     const CFGDeleteDtor &Dtor = Source.castAs<CFGDeleteDtor>();
545     return PathDiagnosticLocation(Dtor.getDeleteExpr(), SM, CallerCtx);
546   }
547   case CFGElement::BaseDtor:
548   case CFGElement::MemberDtor: {
549     const AnalysisDeclContext *CallerInfo = CallerCtx->getAnalysisDeclContext();
550     if (const Stmt *CallerBody = CallerInfo->getBody())
551       return PathDiagnosticLocation::createEnd(CallerBody, SM, CallerCtx);
552     return PathDiagnosticLocation::create(CallerInfo->getDecl(), SM);
553   }
554   case CFGElement::NewAllocator: {
555     const CFGNewAllocator &Alloc = Source.castAs<CFGNewAllocator>();
556     return PathDiagnosticLocation(Alloc.getAllocatorExpr(), SM, CallerCtx);
557   }
558   case CFGElement::TemporaryDtor: {
559     // Temporary destructors are for temporaries. They die immediately at around
560     // the location of CXXBindTemporaryExpr. If they are lifetime-extended,
561     // they'd be dealt with via an AutomaticObjectDtor instead.
562     const auto &Dtor = Source.castAs<CFGTemporaryDtor>();
563     return PathDiagnosticLocation::createEnd(Dtor.getBindTemporaryExpr(), SM,
564                                              CallerCtx);
565   }
566   case CFGElement::ScopeBegin:
567   case CFGElement::ScopeEnd:
568     llvm_unreachable("not yet implemented!");
569   case CFGElement::LifetimeEnds:
570   case CFGElement::LoopExit:
571     llvm_unreachable("CFGElement kind should not be on callsite!");
572   }
573 
574   llvm_unreachable("Unknown CFGElement kind");
575 }
576 
577 PathDiagnosticLocation
578 PathDiagnosticLocation::createBegin(const Decl *D,
579                                     const SourceManager &SM) {
580   return PathDiagnosticLocation(D->getBeginLoc(), SM, SingleLocK);
581 }
582 
583 PathDiagnosticLocation
584 PathDiagnosticLocation::createBegin(const Stmt *S,
585                                     const SourceManager &SM,
586                                     LocationOrAnalysisDeclContext LAC) {
587   return PathDiagnosticLocation(getValidSourceLocation(S, LAC),
588                                 SM, SingleLocK);
589 }
590 
591 PathDiagnosticLocation
592 PathDiagnosticLocation::createEnd(const Stmt *S,
593                                   const SourceManager &SM,
594                                   LocationOrAnalysisDeclContext LAC) {
595   if (const auto *CS = dyn_cast<CompoundStmt>(S))
596     return createEndBrace(CS, SM);
597   return PathDiagnosticLocation(getValidSourceLocation(S, LAC, /*End=*/true),
598                                 SM, SingleLocK);
599 }
600 
601 PathDiagnosticLocation
602 PathDiagnosticLocation::createOperatorLoc(const BinaryOperator *BO,
603                                           const SourceManager &SM) {
604   return PathDiagnosticLocation(BO->getOperatorLoc(), SM, SingleLocK);
605 }
606 
607 PathDiagnosticLocation
608 PathDiagnosticLocation::createConditionalColonLoc(
609                                             const ConditionalOperator *CO,
610                                             const SourceManager &SM) {
611   return PathDiagnosticLocation(CO->getColonLoc(), SM, SingleLocK);
612 }
613 
614 PathDiagnosticLocation
615 PathDiagnosticLocation::createMemberLoc(const MemberExpr *ME,
616                                         const SourceManager &SM) {
617 
618   assert(ME->getMemberLoc().isValid() || ME->getBeginLoc().isValid());
619 
620   // In some cases, getMemberLoc isn't valid -- in this case we'll return with
621   // some other related valid SourceLocation.
622   if (ME->getMemberLoc().isValid())
623     return PathDiagnosticLocation(ME->getMemberLoc(), SM, SingleLocK);
624 
625   return PathDiagnosticLocation(ME->getBeginLoc(), SM, SingleLocK);
626 }
627 
628 PathDiagnosticLocation
629 PathDiagnosticLocation::createBeginBrace(const CompoundStmt *CS,
630                                          const SourceManager &SM) {
631   SourceLocation L = CS->getLBracLoc();
632   return PathDiagnosticLocation(L, SM, SingleLocK);
633 }
634 
635 PathDiagnosticLocation
636 PathDiagnosticLocation::createEndBrace(const CompoundStmt *CS,
637                                        const SourceManager &SM) {
638   SourceLocation L = CS->getRBracLoc();
639   return PathDiagnosticLocation(L, SM, SingleLocK);
640 }
641 
642 PathDiagnosticLocation
643 PathDiagnosticLocation::createDeclBegin(const LocationContext *LC,
644                                         const SourceManager &SM) {
645   // FIXME: Should handle CXXTryStmt if analyser starts supporting C++.
646   if (const auto *CS = dyn_cast_or_null<CompoundStmt>(LC->getDecl()->getBody()))
647     if (!CS->body_empty()) {
648       SourceLocation Loc = (*CS->body_begin())->getBeginLoc();
649       return PathDiagnosticLocation(Loc, SM, SingleLocK);
650     }
651 
652   return PathDiagnosticLocation();
653 }
654 
655 PathDiagnosticLocation
656 PathDiagnosticLocation::createDeclEnd(const LocationContext *LC,
657                                       const SourceManager &SM) {
658   SourceLocation L = LC->getDecl()->getBodyRBrace();
659   return PathDiagnosticLocation(L, SM, SingleLocK);
660 }
661 
662 PathDiagnosticLocation
663 PathDiagnosticLocation::create(const ProgramPoint& P,
664                                const SourceManager &SMng) {
665   const Stmt* S = nullptr;
666   if (std::optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
667     const CFGBlock *BSrc = BE->getSrc();
668     if (BSrc->getTerminator().isVirtualBaseBranch()) {
669       // TODO: VirtualBaseBranches should also appear for destructors.
670       // In this case we should put the diagnostic at the end of decl.
671       return PathDiagnosticLocation::createBegin(
672           P.getLocationContext()->getDecl(), SMng);
673 
674     } else {
675       S = BSrc->getTerminatorCondition();
676       if (!S) {
677         // If the BlockEdge has no terminator condition statement but its
678         // source is the entry of the CFG (e.g. a checker crated the branch at
679         // the beginning of a function), use the function's declaration instead.
680         assert(BSrc == &BSrc->getParent()->getEntry() && "CFGBlock has no "
681                "TerminatorCondition and is not the enrty block of the CFG");
682         return PathDiagnosticLocation::createBegin(
683             P.getLocationContext()->getDecl(), SMng);
684       }
685     }
686   } else if (std::optional<StmtPoint> SP = P.getAs<StmtPoint>()) {
687     S = SP->getStmt();
688     if (P.getAs<PostStmtPurgeDeadSymbols>())
689       return PathDiagnosticLocation::createEnd(S, SMng, P.getLocationContext());
690   } else if (std::optional<PostInitializer> PIP = P.getAs<PostInitializer>()) {
691     return PathDiagnosticLocation(PIP->getInitializer()->getSourceLocation(),
692                                   SMng);
693   } else if (std::optional<PreImplicitCall> PIC = P.getAs<PreImplicitCall>()) {
694     return PathDiagnosticLocation(PIC->getLocation(), SMng);
695   } else if (std::optional<PostImplicitCall> PIE =
696                  P.getAs<PostImplicitCall>()) {
697     return PathDiagnosticLocation(PIE->getLocation(), SMng);
698   } else if (std::optional<CallEnter> CE = P.getAs<CallEnter>()) {
699     return getLocationForCaller(CE->getCalleeContext(),
700                                 CE->getLocationContext(),
701                                 SMng);
702   } else if (std::optional<CallExitEnd> CEE = P.getAs<CallExitEnd>()) {
703     return getLocationForCaller(CEE->getCalleeContext(),
704                                 CEE->getLocationContext(),
705                                 SMng);
706   } else if (auto CEB = P.getAs<CallExitBegin>()) {
707     if (const ReturnStmt *RS = CEB->getReturnStmt())
708       return PathDiagnosticLocation::createBegin(RS, SMng,
709                                                  CEB->getLocationContext());
710     return PathDiagnosticLocation(
711         CEB->getLocationContext()->getDecl()->getSourceRange().getEnd(), SMng);
712   } else if (std::optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) {
713     if (std::optional<CFGElement> BlockFront = BE->getFirstElement()) {
714       if (auto StmtElt = BlockFront->getAs<CFGStmt>()) {
715         return PathDiagnosticLocation(StmtElt->getStmt()->getBeginLoc(), SMng);
716       } else if (auto NewAllocElt = BlockFront->getAs<CFGNewAllocator>()) {
717         return PathDiagnosticLocation(
718             NewAllocElt->getAllocatorExpr()->getBeginLoc(), SMng);
719       }
720       llvm_unreachable("Unexpected CFG element at front of block");
721     }
722 
723     return PathDiagnosticLocation(
724         BE->getBlock()->getTerminatorStmt()->getBeginLoc(), SMng);
725   } else if (std::optional<FunctionExitPoint> FE =
726                  P.getAs<FunctionExitPoint>()) {
727     return PathDiagnosticLocation(FE->getStmt(), SMng,
728                                   FE->getLocationContext());
729   } else {
730     llvm_unreachable("Unexpected ProgramPoint");
731   }
732 
733   return PathDiagnosticLocation(S, SMng, P.getLocationContext());
734 }
735 
736 PathDiagnosticLocation PathDiagnosticLocation::createSingleLocation(
737                                            const PathDiagnosticLocation &PDL) {
738   FullSourceLoc L = PDL.asLocation();
739   return PathDiagnosticLocation(L, L.getManager(), SingleLocK);
740 }
741 
742 FullSourceLoc
743   PathDiagnosticLocation::genLocation(SourceLocation L,
744                                       LocationOrAnalysisDeclContext LAC) const {
745   assert(isValid());
746   // Note that we want a 'switch' here so that the compiler can warn us in
747   // case we add more cases.
748   switch (K) {
749     case SingleLocK:
750     case RangeK:
751       break;
752     case StmtK:
753       // Defensive checking.
754       if (!S)
755         break;
756       return FullSourceLoc(getValidSourceLocation(S, LAC),
757                            const_cast<SourceManager&>(*SM));
758     case DeclK:
759       // Defensive checking.
760       if (!D)
761         break;
762       return FullSourceLoc(D->getLocation(), const_cast<SourceManager&>(*SM));
763   }
764 
765   return FullSourceLoc(L, const_cast<SourceManager&>(*SM));
766 }
767 
768 PathDiagnosticRange
769   PathDiagnosticLocation::genRange(LocationOrAnalysisDeclContext LAC) const {
770   assert(isValid());
771   // Note that we want a 'switch' here so that the compiler can warn us in
772   // case we add more cases.
773   switch (K) {
774     case SingleLocK:
775       return PathDiagnosticRange(SourceRange(Loc,Loc), true);
776     case RangeK:
777       break;
778     case StmtK: {
779       const Stmt *S = asStmt();
780       switch (S->getStmtClass()) {
781         default:
782           break;
783         case Stmt::DeclStmtClass: {
784           const auto *DS = cast<DeclStmt>(S);
785           if (DS->isSingleDecl()) {
786             // Should always be the case, but we'll be defensive.
787             return SourceRange(DS->getBeginLoc(),
788                                DS->getSingleDecl()->getLocation());
789           }
790           break;
791         }
792           // FIXME: Provide better range information for different
793           //  terminators.
794         case Stmt::IfStmtClass:
795         case Stmt::WhileStmtClass:
796         case Stmt::DoStmtClass:
797         case Stmt::ForStmtClass:
798         case Stmt::ChooseExprClass:
799         case Stmt::IndirectGotoStmtClass:
800         case Stmt::SwitchStmtClass:
801         case Stmt::BinaryConditionalOperatorClass:
802         case Stmt::ConditionalOperatorClass:
803         case Stmt::ObjCForCollectionStmtClass: {
804           SourceLocation L = getValidSourceLocation(S, LAC);
805           return SourceRange(L, L);
806         }
807       }
808       SourceRange R = S->getSourceRange();
809       if (R.isValid())
810         return R;
811       break;
812     }
813     case DeclK:
814       if (const auto *MD = dyn_cast<ObjCMethodDecl>(D))
815         return MD->getSourceRange();
816       if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
817         if (Stmt *Body = FD->getBody())
818           return Body->getSourceRange();
819       }
820       else {
821         SourceLocation L = D->getLocation();
822         return PathDiagnosticRange(SourceRange(L, L), true);
823       }
824   }
825 
826   return SourceRange(Loc, Loc);
827 }
828 
829 void PathDiagnosticLocation::flatten() {
830   if (K == StmtK) {
831     K = RangeK;
832     S = nullptr;
833     D = nullptr;
834   }
835   else if (K == DeclK) {
836     K = SingleLocK;
837     S = nullptr;
838     D = nullptr;
839   }
840 }
841 
842 //===----------------------------------------------------------------------===//
843 // Manipulation of PathDiagnosticCallPieces.
844 //===----------------------------------------------------------------------===//
845 
846 std::shared_ptr<PathDiagnosticCallPiece>
847 PathDiagnosticCallPiece::construct(const CallExitEnd &CE,
848                                    const SourceManager &SM) {
849   const Decl *caller = CE.getLocationContext()->getDecl();
850   PathDiagnosticLocation pos = getLocationForCaller(CE.getCalleeContext(),
851                                                     CE.getLocationContext(),
852                                                     SM);
853   return std::shared_ptr<PathDiagnosticCallPiece>(
854       new PathDiagnosticCallPiece(caller, pos));
855 }
856 
857 PathDiagnosticCallPiece *
858 PathDiagnosticCallPiece::construct(PathPieces &path,
859                                    const Decl *caller) {
860   std::shared_ptr<PathDiagnosticCallPiece> C(
861       new PathDiagnosticCallPiece(path, caller));
862   path.clear();
863   auto *R = C.get();
864   path.push_front(std::move(C));
865   return R;
866 }
867 
868 void PathDiagnosticCallPiece::setCallee(const CallEnter &CE,
869                                         const SourceManager &SM) {
870   const StackFrameContext *CalleeCtx = CE.getCalleeContext();
871   Callee = CalleeCtx->getDecl();
872 
873   callEnterWithin = PathDiagnosticLocation::createBegin(Callee, SM);
874   callEnter = getLocationForCaller(CalleeCtx, CE.getLocationContext(), SM);
875 
876   // Autosynthesized property accessors are special because we'd never
877   // pop back up to non-autosynthesized code until we leave them.
878   // This is not generally true for autosynthesized callees, which may call
879   // non-autosynthesized callbacks.
880   // Unless set here, the IsCalleeAnAutosynthesizedPropertyAccessor flag
881   // defaults to false.
882   if (const auto *MD = dyn_cast<ObjCMethodDecl>(Callee))
883     IsCalleeAnAutosynthesizedPropertyAccessor = (
884         MD->isPropertyAccessor() &&
885         CalleeCtx->getAnalysisDeclContext()->isBodyAutosynthesized());
886 }
887 
888 static void describeTemplateParameters(raw_ostream &Out,
889                                        const ArrayRef<TemplateArgument> TAList,
890                                        const LangOptions &LO,
891                                        StringRef Prefix = StringRef(),
892                                        StringRef Postfix = StringRef());
893 
894 static void describeTemplateParameter(raw_ostream &Out,
895                                       const TemplateArgument &TArg,
896                                       const LangOptions &LO) {
897 
898   if (TArg.getKind() == TemplateArgument::ArgKind::Pack) {
899     describeTemplateParameters(Out, TArg.getPackAsArray(), LO);
900   } else {
901     TArg.print(PrintingPolicy(LO), Out, /*IncludeType*/ true);
902   }
903 }
904 
905 static void describeTemplateParameters(raw_ostream &Out,
906                                        const ArrayRef<TemplateArgument> TAList,
907                                        const LangOptions &LO,
908                                        StringRef Prefix, StringRef Postfix) {
909   if (TAList.empty())
910     return;
911 
912   Out << Prefix;
913   for (int I = 0, Last = TAList.size() - 1; I != Last; ++I) {
914     describeTemplateParameter(Out, TAList[I], LO);
915     Out << ", ";
916   }
917   describeTemplateParameter(Out, TAList[TAList.size() - 1], LO);
918   Out << Postfix;
919 }
920 
921 static void describeClass(raw_ostream &Out, const CXXRecordDecl *D,
922                           StringRef Prefix = StringRef()) {
923   if (!D->getIdentifier())
924     return;
925   Out << Prefix << '\'' << *D;
926   if (const auto T = dyn_cast<ClassTemplateSpecializationDecl>(D))
927     describeTemplateParameters(Out, T->getTemplateArgs().asArray(),
928                                D->getLangOpts(), "<", ">");
929 
930   Out << '\'';
931 }
932 
933 static bool describeCodeDecl(raw_ostream &Out, const Decl *D,
934                              bool ExtendedDescription,
935                              StringRef Prefix = StringRef()) {
936   if (!D)
937     return false;
938 
939   if (isa<BlockDecl>(D)) {
940     if (ExtendedDescription)
941       Out << Prefix << "anonymous block";
942     return ExtendedDescription;
943   }
944 
945   if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
946     Out << Prefix;
947     if (ExtendedDescription && !MD->isUserProvided()) {
948       if (MD->isExplicitlyDefaulted())
949         Out << "defaulted ";
950       else
951         Out << "implicit ";
952     }
953 
954     if (const auto *CD = dyn_cast<CXXConstructorDecl>(MD)) {
955       if (CD->isDefaultConstructor())
956         Out << "default ";
957       else if (CD->isCopyConstructor())
958         Out << "copy ";
959       else if (CD->isMoveConstructor())
960         Out << "move ";
961 
962       Out << "constructor";
963       describeClass(Out, MD->getParent(), " for ");
964     } else if (isa<CXXDestructorDecl>(MD)) {
965       if (!MD->isUserProvided()) {
966         Out << "destructor";
967         describeClass(Out, MD->getParent(), " for ");
968       } else {
969         // Use ~Foo for explicitly-written destructors.
970         Out << "'" << *MD << "'";
971       }
972     } else if (MD->isCopyAssignmentOperator()) {
973         Out << "copy assignment operator";
974         describeClass(Out, MD->getParent(), " for ");
975     } else if (MD->isMoveAssignmentOperator()) {
976         Out << "move assignment operator";
977         describeClass(Out, MD->getParent(), " for ");
978     } else {
979       if (MD->getParent()->getIdentifier())
980         Out << "'" << *MD->getParent() << "::" << *MD << "'";
981       else
982         Out << "'" << *MD << "'";
983     }
984 
985     return true;
986   }
987 
988   Out << Prefix << '\'' << cast<NamedDecl>(*D);
989 
990   // Adding template parameters.
991   if (const auto FD = dyn_cast<FunctionDecl>(D))
992     if (const TemplateArgumentList *TAList =
993                                     FD->getTemplateSpecializationArgs())
994       describeTemplateParameters(Out, TAList->asArray(), FD->getLangOpts(), "<",
995                                  ">");
996 
997   Out << '\'';
998   return true;
999 }
1000 
1001 std::shared_ptr<PathDiagnosticEventPiece>
1002 PathDiagnosticCallPiece::getCallEnterEvent() const {
1003   // We do not produce call enters and call exits for autosynthesized property
1004   // accessors. We do generally produce them for other functions coming from
1005   // the body farm because they may call callbacks that bring us back into
1006   // visible code.
1007   if (!Callee || IsCalleeAnAutosynthesizedPropertyAccessor)
1008     return nullptr;
1009 
1010   SmallString<256> buf;
1011   llvm::raw_svector_ostream Out(buf);
1012 
1013   Out << "Calling ";
1014   describeCodeDecl(Out, Callee, /*ExtendedDescription=*/true);
1015 
1016   assert(callEnter.asLocation().isValid());
1017   return std::make_shared<PathDiagnosticEventPiece>(callEnter, Out.str());
1018 }
1019 
1020 std::shared_ptr<PathDiagnosticEventPiece>
1021 PathDiagnosticCallPiece::getCallEnterWithinCallerEvent() const {
1022   if (!callEnterWithin.asLocation().isValid())
1023     return nullptr;
1024   if (Callee->isImplicit() || !Callee->hasBody())
1025     return nullptr;
1026   if (const auto *MD = dyn_cast<CXXMethodDecl>(Callee))
1027     if (MD->isDefaulted())
1028       return nullptr;
1029 
1030   SmallString<256> buf;
1031   llvm::raw_svector_ostream Out(buf);
1032 
1033   Out << "Entered call";
1034   describeCodeDecl(Out, Caller, /*ExtendedDescription=*/false, " from ");
1035 
1036   return std::make_shared<PathDiagnosticEventPiece>(callEnterWithin, Out.str());
1037 }
1038 
1039 std::shared_ptr<PathDiagnosticEventPiece>
1040 PathDiagnosticCallPiece::getCallExitEvent() const {
1041   // We do not produce call enters and call exits for autosynthesized property
1042   // accessors. We do generally produce them for other functions coming from
1043   // the body farm because they may call callbacks that bring us back into
1044   // visible code.
1045   if (NoExit || IsCalleeAnAutosynthesizedPropertyAccessor)
1046     return nullptr;
1047 
1048   SmallString<256> buf;
1049   llvm::raw_svector_ostream Out(buf);
1050 
1051   if (!CallStackMessage.empty()) {
1052     Out << CallStackMessage;
1053   } else {
1054     bool DidDescribe = describeCodeDecl(Out, Callee,
1055                                         /*ExtendedDescription=*/false,
1056                                         "Returning from ");
1057     if (!DidDescribe)
1058       Out << "Returning to caller";
1059   }
1060 
1061   assert(callReturn.asLocation().isValid());
1062   return std::make_shared<PathDiagnosticEventPiece>(callReturn, Out.str());
1063 }
1064 
1065 static void compute_path_size(const PathPieces &pieces, unsigned &size) {
1066   for (const auto &I : pieces) {
1067     const PathDiagnosticPiece *piece = I.get();
1068     if (const auto *cp = dyn_cast<PathDiagnosticCallPiece>(piece))
1069       compute_path_size(cp->path, size);
1070     else
1071       ++size;
1072   }
1073 }
1074 
1075 unsigned PathDiagnostic::full_size() {
1076   unsigned size = 0;
1077   compute_path_size(path, size);
1078   return size;
1079 }
1080 
1081 //===----------------------------------------------------------------------===//
1082 // FoldingSet profiling methods.
1083 //===----------------------------------------------------------------------===//
1084 
1085 void PathDiagnosticLocation::Profile(llvm::FoldingSetNodeID &ID) const {
1086   ID.Add(Range.getBegin());
1087   ID.Add(Range.getEnd());
1088   ID.Add(static_cast<const SourceLocation &>(Loc));
1089 }
1090 
1091 void PathDiagnosticPiece::Profile(llvm::FoldingSetNodeID &ID) const {
1092   ID.AddInteger((unsigned) getKind());
1093   ID.AddString(str);
1094   // FIXME: Add profiling support for code hints.
1095   ID.AddInteger((unsigned) getDisplayHint());
1096   ArrayRef<SourceRange> Ranges = getRanges();
1097   for (const auto &I : Ranges) {
1098     ID.Add(I.getBegin());
1099     ID.Add(I.getEnd());
1100   }
1101 }
1102 
1103 void PathDiagnosticCallPiece::Profile(llvm::FoldingSetNodeID &ID) const {
1104   PathDiagnosticPiece::Profile(ID);
1105   for (const auto &I : path)
1106     ID.Add(*I);
1107 }
1108 
1109 void PathDiagnosticSpotPiece::Profile(llvm::FoldingSetNodeID &ID) const {
1110   PathDiagnosticPiece::Profile(ID);
1111   ID.Add(Pos);
1112 }
1113 
1114 void PathDiagnosticControlFlowPiece::Profile(llvm::FoldingSetNodeID &ID) const {
1115   PathDiagnosticPiece::Profile(ID);
1116   for (const auto &I : *this)
1117     ID.Add(I);
1118 }
1119 
1120 void PathDiagnosticMacroPiece::Profile(llvm::FoldingSetNodeID &ID) const {
1121   PathDiagnosticSpotPiece::Profile(ID);
1122   for (const auto &I : subPieces)
1123     ID.Add(*I);
1124 }
1125 
1126 void PathDiagnosticNotePiece::Profile(llvm::FoldingSetNodeID &ID) const {
1127   PathDiagnosticSpotPiece::Profile(ID);
1128 }
1129 
1130 void PathDiagnosticPopUpPiece::Profile(llvm::FoldingSetNodeID &ID) const {
1131   PathDiagnosticSpotPiece::Profile(ID);
1132 }
1133 
1134 void PathDiagnostic::Profile(llvm::FoldingSetNodeID &ID) const {
1135   ID.Add(getLocation());
1136   ID.Add(getUniqueingLoc());
1137   ID.AddString(BugType);
1138   ID.AddString(VerboseDesc);
1139   ID.AddString(Category);
1140 }
1141 
1142 void PathDiagnostic::FullProfile(llvm::FoldingSetNodeID &ID) const {
1143   Profile(ID);
1144   for (const auto &I : path)
1145     ID.Add(*I);
1146   for (meta_iterator I = meta_begin(), E = meta_end(); I != E; ++I)
1147     ID.AddString(*I);
1148 }
1149 
1150 LLVM_DUMP_METHOD void PathPieces::dump() const {
1151   unsigned index = 0;
1152   for (PathPieces::const_iterator I = begin(), E = end(); I != E; ++I) {
1153     llvm::errs() << "[" << index++ << "]  ";
1154     (*I)->dump();
1155     llvm::errs() << "\n";
1156   }
1157 }
1158 
1159 LLVM_DUMP_METHOD void PathDiagnosticCallPiece::dump() const {
1160   llvm::errs() << "CALL\n--------------\n";
1161 
1162   if (const Stmt *SLoc = getLocation().getStmtOrNull())
1163     SLoc->dump();
1164   else if (const auto *ND = dyn_cast_or_null<NamedDecl>(getCallee()))
1165     llvm::errs() << *ND << "\n";
1166   else
1167     getLocation().dump();
1168 }
1169 
1170 LLVM_DUMP_METHOD void PathDiagnosticEventPiece::dump() const {
1171   llvm::errs() << "EVENT\n--------------\n";
1172   llvm::errs() << getString() << "\n";
1173   llvm::errs() << " ---- at ----\n";
1174   getLocation().dump();
1175 }
1176 
1177 LLVM_DUMP_METHOD void PathDiagnosticControlFlowPiece::dump() const {
1178   llvm::errs() << "CONTROL\n--------------\n";
1179   getStartLocation().dump();
1180   llvm::errs() << " ---- to ----\n";
1181   getEndLocation().dump();
1182 }
1183 
1184 LLVM_DUMP_METHOD void PathDiagnosticMacroPiece::dump() const {
1185   llvm::errs() << "MACRO\n--------------\n";
1186   // FIXME: Print which macro is being invoked.
1187 }
1188 
1189 LLVM_DUMP_METHOD void PathDiagnosticNotePiece::dump() const {
1190   llvm::errs() << "NOTE\n--------------\n";
1191   llvm::errs() << getString() << "\n";
1192   llvm::errs() << " ---- at ----\n";
1193   getLocation().dump();
1194 }
1195 
1196 LLVM_DUMP_METHOD void PathDiagnosticPopUpPiece::dump() const {
1197   llvm::errs() << "POP-UP\n--------------\n";
1198   llvm::errs() << getString() << "\n";
1199   llvm::errs() << " ---- at ----\n";
1200   getLocation().dump();
1201 }
1202 
1203 LLVM_DUMP_METHOD void PathDiagnosticLocation::dump() const {
1204   if (!isValid()) {
1205     llvm::errs() << "<INVALID>\n";
1206     return;
1207   }
1208 
1209   switch (K) {
1210   case RangeK:
1211     // FIXME: actually print the range.
1212     llvm::errs() << "<range>\n";
1213     break;
1214   case SingleLocK:
1215     asLocation().dump();
1216     llvm::errs() << "\n";
1217     break;
1218   case StmtK:
1219     if (S)
1220       S->dump();
1221     else
1222       llvm::errs() << "<NULL STMT>\n";
1223     break;
1224   case DeclK:
1225     if (const auto *ND = dyn_cast_or_null<NamedDecl>(D))
1226       llvm::errs() << *ND << "\n";
1227     else if (isa<BlockDecl>(D))
1228       // FIXME: Make this nicer.
1229       llvm::errs() << "<block>\n";
1230     else if (D)
1231       llvm::errs() << "<unknown decl>\n";
1232     else
1233       llvm::errs() << "<NULL DECL>\n";
1234     break;
1235   }
1236 }
1237