1//===- BugReporter.cpp - Generate PathDiagnostics for bugs ----------------===//
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 BugReporter, a utility class for generating
10// PathDiagnostics.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
15#include "clang/AST/ASTTypeTraits.h"
16#include "clang/AST/Attr.h"
17#include "clang/AST/Decl.h"
18#include "clang/AST/DeclBase.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/ParentMap.h"
23#include "clang/AST/Stmt.h"
24#include "clang/AST/StmtCXX.h"
25#include "clang/AST/StmtObjC.h"
26#include "clang/Analysis/AnalysisDeclContext.h"
27#include "clang/Analysis/CFG.h"
28#include "clang/Analysis/PathDiagnostic.h"
29#include "clang/Analysis/ProgramPoint.h"
30#include "clang/Basic/LLVM.h"
31#include "clang/Basic/SourceLocation.h"
32#include "clang/Basic/SourceManager.h"
33#include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
34#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
35#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
36#include "clang/StaticAnalyzer/Core/BugReporter/Z3CrosscheckVisitor.h"
37#include "clang/StaticAnalyzer/Core/Checker.h"
38#include "clang/StaticAnalyzer/Core/CheckerManager.h"
39#include "clang/StaticAnalyzer/Core/CheckerRegistryData.h"
40#include "clang/StaticAnalyzer/Core/PathSensitive/EntryPointStats.h"
41#include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
42#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
43#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
44#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
45#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
46#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
47#include "llvm/ADT/ArrayRef.h"
48#include "llvm/ADT/DenseMap.h"
49#include "llvm/ADT/DenseSet.h"
50#include "llvm/ADT/FoldingSet.h"
51#include "llvm/ADT/STLExtras.h"
52#include "llvm/ADT/SmallPtrSet.h"
53#include "llvm/ADT/StringExtras.h"
54#include "llvm/ADT/StringRef.h"
55#include "llvm/Support/Compiler.h"
56#include "llvm/Support/ErrorHandling.h"
57#include "llvm/Support/TimeProfiler.h"
58#include "llvm/Support/raw_ostream.h"
59#include <algorithm>
60#include <cassert>
61#include <cstddef>
62#include <iterator>
63#include <memory>
64#include <optional>
65#include <queue>
66#include <string>
67#include <tuple>
68#include <utility>
69#include <vector>
70
71using namespace clang;
72using namespace ento;
73using namespace llvm;
74
75#define DEBUG_TYPE "BugReporter"
76
77STAT_MAX(MaxBugClassSize,
78 "The maximum number of bug reports in the same equivalence class");
79STAT_MAX(MaxValidBugClassSize,
80 "The maximum number of bug reports in the same equivalence class "
81 "where at least one report is valid (not suppressed)");
82
83STAT_COUNTER(NumTimesReportPassesZ3, "Number of reports passed Z3");
84STAT_COUNTER(NumTimesReportRefuted, "Number of reports refuted by Z3");
85STAT_COUNTER(NumTimesReportEQClassAborted,
86 "Number of times a report equivalence class was aborted by the Z3 "
87 "oracle heuristic");
88STAT_COUNTER(NumTimesReportEQClassWasExhausted,
89 "Number of times all reports of an equivalence class was refuted");
90
91BugReporterVisitor::~BugReporterVisitor() = default;
92
93void BugReporterContext::anchor() {}
94
95//===----------------------------------------------------------------------===//
96// PathDiagnosticBuilder and its associated routines and helper objects.
97//===----------------------------------------------------------------------===//
98
99namespace {
100
101/// A (CallPiece, node assiciated with its CallEnter) pair.
102using CallWithEntry =
103 std::pair<PathDiagnosticCallPiece *, const ExplodedNode *>;
104using CallWithEntryStack = SmallVector<CallWithEntry, 6>;
105
106/// Map from each node to the diagnostic pieces visitors emit for them.
107using VisitorsDiagnosticsTy =
108 llvm::DenseMap<const ExplodedNode *, std::vector<PathDiagnosticPieceRef>>;
109
110/// A map from PathDiagnosticPiece to the LocationContext of the inlined
111/// function call it represents.
112using LocationContextMap =
113 llvm::DenseMap<const PathPieces *, const LocationContext *>;
114
115/// A helper class that contains everything needed to construct a
116/// PathDiagnostic object. It does no much more then providing convenient
117/// getters and some well placed asserts for extra security.
118class PathDiagnosticConstruct {
119 /// The consumer we're constructing the bug report for.
120 const PathDiagnosticConsumer *Consumer;
121 /// Our current position in the bug path, which is owned by
122 /// PathDiagnosticBuilder.
123 const ExplodedNode *CurrentNode;
124 /// A mapping from parts of the bug path (for example, a function call, which
125 /// would span backwards from a CallExit to a CallEnter with the nodes in
126 /// between them) with the location contexts it is associated with.
127 LocationContextMap LCM;
128 const SourceManager &SM;
129
130public:
131 /// We keep stack of calls to functions as we're ascending the bug path.
132 /// TODO: PathDiagnostic has a stack doing the same thing, shouldn't we use
133 /// that instead?
134 CallWithEntryStack CallStack;
135 /// The bug report we're constructing. For ease of use, this field is kept
136 /// public, though some "shortcut" getters are provided for commonly used
137 /// methods of PathDiagnostic.
138 std::unique_ptr<PathDiagnostic> PD;
139
140public:
141 PathDiagnosticConstruct(const PathDiagnosticConsumer *PDC,
142 const ExplodedNode *ErrorNode,
143 const PathSensitiveBugReport *R,
144 const Decl *AnalysisEntryPoint);
145
146 /// \returns the location context associated with the current position in the
147 /// bug path.
148 const LocationContext *getCurrLocationContext() const {
149 assert(CurrentNode && "Already reached the root!");
150 return CurrentNode->getLocationContext();
151 }
152
153 /// Same as getCurrLocationContext (they should always return the same
154 /// location context), but works after reaching the root of the bug path as
155 /// well.
156 const LocationContext *getLocationContextForActivePath() const {
157 return LCM.find(Val: &PD->getActivePath())->getSecond();
158 }
159
160 const ExplodedNode *getCurrentNode() const { return CurrentNode; }
161
162 /// Steps the current node to its predecessor.
163 /// \returns whether we reached the root of the bug path.
164 bool ascendToPrevNode() {
165 CurrentNode = CurrentNode->getFirstPred();
166 return static_cast<bool>(CurrentNode);
167 }
168
169 const ParentMap &getParentMap() const {
170 return getCurrLocationContext()->getParentMap();
171 }
172
173 const SourceManager &getSourceManager() const { return SM; }
174
175 const Stmt *getParent(const Stmt *S) const {
176 return getParentMap().getParent(S);
177 }
178
179 void updateLocCtxMap(const PathPieces *Path, const LocationContext *LC) {
180 assert(Path && LC);
181 LCM[Path] = LC;
182 }
183
184 const LocationContext *getLocationContextFor(const PathPieces *Path) const {
185 assert(LCM.count(Path) &&
186 "Failed to find the context associated with these pieces!");
187 return LCM.find(Val: Path)->getSecond();
188 }
189
190 bool isInLocCtxMap(const PathPieces *Path) const { return LCM.count(Val: Path); }
191
192 PathPieces &getActivePath() { return PD->getActivePath(); }
193 PathPieces &getMutablePieces() { return PD->getMutablePieces(); }
194
195 bool shouldAddPathEdges() const { return Consumer->shouldAddPathEdges(); }
196 bool shouldAddControlNotes() const {
197 return Consumer->shouldAddControlNotes();
198 }
199 bool shouldGenerateDiagnostics() const {
200 return Consumer->shouldGenerateDiagnostics();
201 }
202 bool supportsLogicalOpControlFlow() const {
203 return Consumer->supportsLogicalOpControlFlow();
204 }
205};
206
207/// Contains every contextual information needed for constructing a
208/// PathDiagnostic object for a given bug report. This class and its fields are
209/// immutable, and passes a BugReportConstruct object around during the
210/// construction.
211class PathDiagnosticBuilder : public BugReporterContext {
212 /// A linear path from the error node to the root.
213 std::unique_ptr<const ExplodedGraph> BugPath;
214 /// The bug report we're describing. Visitors create their diagnostics with
215 /// them being the last entities being able to modify it (for example,
216 /// changing interestingness here would cause inconsistencies as to how this
217 /// file and visitors construct diagnostics), hence its const.
218 const PathSensitiveBugReport *R;
219 /// The leaf of the bug path. This isn't the same as the bug reports error
220 /// node, which refers to the *original* graph, not the bug path.
221 const ExplodedNode *const ErrorNode;
222 /// The diagnostic pieces visitors emitted, which is expected to be collected
223 /// by the time this builder is constructed.
224 std::unique_ptr<const VisitorsDiagnosticsTy> VisitorsDiagnostics;
225
226public:
227 /// Find a non-invalidated report for a given equivalence class, and returns
228 /// a PathDiagnosticBuilder able to construct bug reports for different
229 /// consumers. Returns std::nullopt if no valid report is found.
230 static std::optional<PathDiagnosticBuilder>
231 findValidReport(ArrayRef<PathSensitiveBugReport *> &bugReports,
232 PathSensitiveBugReporter &Reporter);
233
234 PathDiagnosticBuilder(
235 BugReporterContext BRC, std::unique_ptr<ExplodedGraph> BugPath,
236 PathSensitiveBugReport *r, const ExplodedNode *ErrorNode,
237 std::unique_ptr<VisitorsDiagnosticsTy> VisitorsDiagnostics);
238
239 /// This function is responsible for generating diagnostic pieces that are
240 /// *not* provided by bug report visitors.
241 /// These diagnostics may differ depending on the consumer's settings,
242 /// and are therefore constructed separately for each consumer.
243 ///
244 /// There are two path diagnostics generation modes: with adding edges (used
245 /// for plists) and without (used for HTML and text). When edges are added,
246 /// the path is modified to insert artificially generated edges.
247 /// Otherwise, more detailed diagnostics is emitted for block edges,
248 /// explaining the transitions in words.
249 std::unique_ptr<PathDiagnostic>
250 generate(const PathDiagnosticConsumer *PDC) const;
251
252private:
253 void updateStackPiecesWithMessage(PathDiagnosticPieceRef P,
254 const CallWithEntryStack &CallStack) const;
255 void generatePathDiagnosticsForNode(PathDiagnosticConstruct &C,
256 PathDiagnosticLocation &PrevLoc) const;
257
258 void generateMinimalDiagForBlockEdge(PathDiagnosticConstruct &C,
259 BlockEdge BE) const;
260
261 PathDiagnosticPieceRef
262 generateDiagForGotoOP(const PathDiagnosticConstruct &C, const Stmt *S,
263 PathDiagnosticLocation &Start) const;
264
265 PathDiagnosticPieceRef
266 generateDiagForSwitchOP(const PathDiagnosticConstruct &C, const CFGBlock *Dst,
267 PathDiagnosticLocation &Start) const;
268
269 PathDiagnosticPieceRef
270 generateDiagForBinaryOP(const PathDiagnosticConstruct &C, const Stmt *T,
271 const CFGBlock *Src, const CFGBlock *DstC) const;
272
273 PathDiagnosticLocation
274 ExecutionContinues(const PathDiagnosticConstruct &C) const;
275
276 PathDiagnosticLocation
277 ExecutionContinues(llvm::raw_string_ostream &os,
278 const PathDiagnosticConstruct &C) const;
279
280 const PathSensitiveBugReport *getBugReport() const { return R; }
281};
282
283std::string timeTraceName(const BugReportEquivClass &EQ) {
284 if (!llvm::timeTraceProfilerEnabled())
285 return "";
286 const auto &BugReports = EQ.getReports();
287 if (BugReports.empty())
288 return "Empty Equivalence Class";
289 const BugReport *R = BugReports.front().get();
290 const auto &BT = R->getBugType();
291 return ("Flushing EQC " + BT.getDescription()).str();
292}
293
294llvm::TimeTraceMetadata timeTraceMetadata(const BugReportEquivClass &EQ,
295 const SourceManager &SM) {
296 // Must be called only when constructing non-bogus TimeTraceScope
297 assert(llvm::timeTraceProfilerEnabled());
298
299 const auto &BugReports = EQ.getReports();
300 if (BugReports.empty())
301 return {};
302 const BugReport *R = BugReports.front().get();
303 const auto &BT = R->getBugType();
304 auto Loc = R->getLocation().asLocation();
305 std::string File = SM.getFilename(SpellingLoc: Loc).str();
306 return {.Detail: BT.getCheckerName().str(), .File: std::move(File),
307 .Line: static_cast<int>(Loc.getLineNumber())};
308}
309
310} // namespace
311
312//===----------------------------------------------------------------------===//
313// Base implementation of stack hint generators.
314//===----------------------------------------------------------------------===//
315
316StackHintGenerator::~StackHintGenerator() = default;
317
318std::string StackHintGeneratorForSymbol::getMessage(const ExplodedNode *N){
319 if (!N)
320 return getMessageForSymbolNotFound();
321
322 ProgramPoint P = N->getLocation();
323 CallExitEnd CExit = P.castAs<CallExitEnd>();
324
325 // FIXME: Use CallEvent to abstract this over all calls.
326 const Stmt *CallSite = CExit.getCalleeContext()->getCallSite();
327 const auto *CE = dyn_cast_or_null<CallExpr>(Val: CallSite);
328 if (!CE)
329 return {};
330
331 // Check if one of the parameters are set to the interesting symbol.
332 for (auto [Idx, ArgExpr] : llvm::enumerate(First: CE->arguments())) {
333 SVal SV = N->getSVal(S: ArgExpr);
334
335 // Check if the variable corresponding to the symbol is passed by value.
336 SymbolRef AS = SV.getAsLocSymbol();
337 if (AS == Sym) {
338 return getMessageForArg(ArgE: ArgExpr, ArgIndex: Idx);
339 }
340
341 // Check if the parameter is a pointer to the symbol.
342 if (std::optional<loc::MemRegionVal> Reg = SV.getAs<loc::MemRegionVal>()) {
343 // Do not attempt to dereference void*.
344 if (ArgExpr->getType()->isVoidPointerType())
345 continue;
346 SVal PSV = N->getState()->getSVal(R: Reg->getRegion());
347 SymbolRef AS = PSV.getAsLocSymbol();
348 if (AS == Sym) {
349 return getMessageForArg(ArgE: ArgExpr, ArgIndex: Idx);
350 }
351 }
352 }
353
354 // Check if we are returning the interesting symbol.
355 SVal SV = N->getSVal(S: CE);
356 SymbolRef RetSym = SV.getAsLocSymbol();
357 if (RetSym == Sym) {
358 return getMessageForReturn(CallExpr: CE);
359 }
360
361 return getMessageForSymbolNotFound();
362}
363
364std::string StackHintGeneratorForSymbol::getMessageForArg(const Expr *ArgE,
365 unsigned ArgIndex) {
366 // Printed parameters start at 1, not 0.
367 ++ArgIndex;
368
369 return (llvm::Twine(Msg) + " via " + std::to_string(val: ArgIndex) +
370 llvm::getOrdinalSuffix(Val: ArgIndex) + " parameter").str();
371}
372
373//===----------------------------------------------------------------------===//
374// Diagnostic cleanup.
375//===----------------------------------------------------------------------===//
376
377static PathDiagnosticEventPiece *
378eventsDescribeSameCondition(PathDiagnosticEventPiece *X,
379 PathDiagnosticEventPiece *Y) {
380 // Prefer diagnostics that come from ConditionBRVisitor over
381 // those that came from TrackConstraintBRVisitor,
382 // unless the one from ConditionBRVisitor is
383 // its generic fallback diagnostic.
384 const void *tagPreferred = ConditionBRVisitor::getTag();
385 const void *tagLesser = TrackConstraintBRVisitor::getTag();
386
387 if (X->getLocation() != Y->getLocation())
388 return nullptr;
389
390 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
391 return ConditionBRVisitor::isPieceMessageGeneric(Piece: X) ? Y : X;
392
393 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
394 return ConditionBRVisitor::isPieceMessageGeneric(Piece: Y) ? X : Y;
395
396 return nullptr;
397}
398
399/// An optimization pass over PathPieces that removes redundant diagnostics
400/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both
401/// BugReporterVisitors use different methods to generate diagnostics, with
402/// one capable of emitting diagnostics in some cases but not in others. This
403/// can lead to redundant diagnostic pieces at the same point in a path.
404static void removeRedundantMsgs(PathPieces &path) {
405 unsigned N = path.size();
406 if (N < 2)
407 return;
408 // NOTE: this loop intentionally is not using an iterator. Instead, we
409 // are streaming the path and modifying it in place. This is done by
410 // grabbing the front, processing it, and if we decide to keep it append
411 // it to the end of the path. The entire path is processed in this way.
412 for (unsigned i = 0; i < N; ++i) {
413 auto piece = std::move(path.front());
414 path.pop_front();
415
416 switch (piece->getKind()) {
417 case PathDiagnosticPiece::Call:
418 removeRedundantMsgs(path&: cast<PathDiagnosticCallPiece>(Val&: *piece).path);
419 break;
420 case PathDiagnosticPiece::Macro:
421 removeRedundantMsgs(path&: cast<PathDiagnosticMacroPiece>(Val&: *piece).subPieces);
422 break;
423 case PathDiagnosticPiece::Event: {
424 if (i == N-1)
425 break;
426
427 if (auto *nextEvent =
428 dyn_cast<PathDiagnosticEventPiece>(Val: path.front().get())) {
429 auto *event = cast<PathDiagnosticEventPiece>(Val: piece.get());
430 // Check to see if we should keep one of the two pieces. If we
431 // come up with a preference, record which piece to keep, and consume
432 // another piece from the path.
433 if (auto *pieceToKeep =
434 eventsDescribeSameCondition(X: event, Y: nextEvent)) {
435 piece = std::move(pieceToKeep == event ? piece : path.front());
436 path.pop_front();
437 ++i;
438 }
439 }
440 break;
441 }
442 case PathDiagnosticPiece::ControlFlow:
443 case PathDiagnosticPiece::Note:
444 case PathDiagnosticPiece::PopUp:
445 break;
446 }
447 path.push_back(x: std::move(piece));
448 }
449}
450
451/// Recursively scan through a path and prune out calls and macros pieces
452/// that aren't needed. Return true if afterwards the path contains
453/// "interesting stuff" which means it shouldn't be pruned from the parent path.
454static bool removeUnneededCalls(const PathDiagnosticConstruct &C,
455 PathPieces &pieces,
456 const PathSensitiveBugReport *R,
457 bool IsInteresting = false) {
458 bool containsSomethingInteresting = IsInteresting;
459 const unsigned N = pieces.size();
460
461 for (unsigned i = 0 ; i < N ; ++i) {
462 // Remove the front piece from the path. If it is still something we
463 // want to keep once we are done, we will push it back on the end.
464 auto piece = std::move(pieces.front());
465 pieces.pop_front();
466
467 switch (piece->getKind()) {
468 case PathDiagnosticPiece::Call: {
469 auto &call = cast<PathDiagnosticCallPiece>(Val&: *piece);
470 // Check if the location context is interesting.
471 if (!removeUnneededCalls(
472 C, pieces&: call.path, R,
473 IsInteresting: R->isInteresting(LC: C.getLocationContextFor(Path: &call.path))))
474 continue;
475
476 containsSomethingInteresting = true;
477 break;
478 }
479 case PathDiagnosticPiece::Macro: {
480 auto &macro = cast<PathDiagnosticMacroPiece>(Val&: *piece);
481 if (!removeUnneededCalls(C, pieces&: macro.subPieces, R, IsInteresting))
482 continue;
483 containsSomethingInteresting = true;
484 break;
485 }
486 case PathDiagnosticPiece::Event: {
487 auto &event = cast<PathDiagnosticEventPiece>(Val&: *piece);
488
489 // We never throw away an event, but we do throw it away wholesale
490 // as part of a path if we throw the entire path away.
491 containsSomethingInteresting |= !event.isPrunable();
492 break;
493 }
494 case PathDiagnosticPiece::ControlFlow:
495 case PathDiagnosticPiece::Note:
496 case PathDiagnosticPiece::PopUp:
497 break;
498 }
499
500 pieces.push_back(x: std::move(piece));
501 }
502
503 return containsSomethingInteresting;
504}
505
506/// Same logic as above to remove extra pieces.
507static void removePopUpNotes(PathPieces &Path) {
508 for (unsigned int i = 0; i < Path.size(); ++i) {
509 auto Piece = std::move(Path.front());
510 Path.pop_front();
511 if (!isa<PathDiagnosticPopUpPiece>(Val: *Piece))
512 Path.push_back(x: std::move(Piece));
513 }
514}
515
516/// Returns true if the given decl has been implicitly given a body, either by
517/// the analyzer or by the compiler proper.
518static bool hasImplicitBody(const Decl *D) {
519 assert(D);
520 return D->isImplicit() || !D->hasBody();
521}
522
523/// Recursively scan through a path and make sure that all call pieces have
524/// valid locations.
525static void
526adjustCallLocations(PathPieces &Pieces,
527 PathDiagnosticLocation *LastCallLocation = nullptr) {
528 for (const auto &I : Pieces) {
529 auto *Call = dyn_cast<PathDiagnosticCallPiece>(Val: I.get());
530
531 if (!Call)
532 continue;
533
534 if (LastCallLocation) {
535 bool CallerIsImplicit = hasImplicitBody(D: Call->getCaller());
536 if (CallerIsImplicit || !Call->callEnter.asLocation().isValid())
537 Call->callEnter = *LastCallLocation;
538 if (CallerIsImplicit || !Call->callReturn.asLocation().isValid())
539 Call->callReturn = *LastCallLocation;
540 }
541
542 // Recursively clean out the subclass. Keep this call around if
543 // it contains any informative diagnostics.
544 PathDiagnosticLocation *ThisCallLocation;
545 if (Call->callEnterWithin.asLocation().isValid() &&
546 !hasImplicitBody(D: Call->getCallee()))
547 ThisCallLocation = &Call->callEnterWithin;
548 else
549 ThisCallLocation = &Call->callEnter;
550
551 assert(ThisCallLocation && "Outermost call has an invalid location");
552 adjustCallLocations(Pieces&: Call->path, LastCallLocation: ThisCallLocation);
553 }
554}
555
556/// Remove edges in and out of C++ default initializer expressions. These are
557/// for fields that have in-class initializers, as opposed to being initialized
558/// explicitly in a constructor or braced list.
559static void removeEdgesToDefaultInitializers(PathPieces &Pieces) {
560 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
561 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(Val: I->get()))
562 removeEdgesToDefaultInitializers(Pieces&: C->path);
563
564 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(Val: I->get()))
565 removeEdgesToDefaultInitializers(Pieces&: M->subPieces);
566
567 if (auto *CF = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get())) {
568 const Stmt *Start = CF->getStartLocation().asStmt();
569 const Stmt *End = CF->getEndLocation().asStmt();
570 if (isa_and_nonnull<CXXDefaultInitExpr>(Val: Start)) {
571 I = Pieces.erase(position: I);
572 continue;
573 } else if (isa_and_nonnull<CXXDefaultInitExpr>(Val: End)) {
574 PathPieces::iterator Next = std::next(x: I);
575 if (Next != E) {
576 if (auto *NextCF =
577 dyn_cast<PathDiagnosticControlFlowPiece>(Val: Next->get())) {
578 NextCF->setStartLocation(CF->getStartLocation());
579 }
580 }
581 I = Pieces.erase(position: I);
582 continue;
583 }
584 }
585
586 I++;
587 }
588}
589
590/// Remove all pieces with invalid locations as these cannot be serialized.
591/// We might have pieces with invalid locations as a result of inlining Body
592/// Farm generated functions.
593static void removePiecesWithInvalidLocations(PathPieces &Pieces) {
594 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
595 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(Val: I->get()))
596 removePiecesWithInvalidLocations(Pieces&: C->path);
597
598 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(Val: I->get()))
599 removePiecesWithInvalidLocations(Pieces&: M->subPieces);
600
601 if (!(*I)->getLocation().isValid() ||
602 !(*I)->getLocation().asLocation().isValid()) {
603 I = Pieces.erase(position: I);
604 continue;
605 }
606 I++;
607 }
608}
609
610PathDiagnosticLocation PathDiagnosticBuilder::ExecutionContinues(
611 const PathDiagnosticConstruct &C) const {
612 if (const Stmt *S = C.getCurrentNode()->getNextStmtForDiagnostics())
613 return PathDiagnosticLocation(S, getSourceManager(),
614 C.getCurrLocationContext());
615
616 return PathDiagnosticLocation::createDeclEnd(LC: C.getCurrLocationContext(),
617 SM: getSourceManager());
618}
619
620PathDiagnosticLocation PathDiagnosticBuilder::ExecutionContinues(
621 llvm::raw_string_ostream &os, const PathDiagnosticConstruct &C) const {
622 // Slow, but probably doesn't matter.
623 if (os.str().empty())
624 os << ' ';
625
626 const PathDiagnosticLocation &Loc = ExecutionContinues(C);
627
628 if (Loc.asStmt())
629 os << "Execution continues on line "
630 << getSourceManager().getExpansionLineNumber(Loc: Loc.asLocation())
631 << '.';
632 else {
633 os << "Execution jumps to the end of the ";
634 const Decl *D = C.getCurrLocationContext()->getDecl();
635 if (isa<ObjCMethodDecl>(Val: D))
636 os << "method";
637 else if (isa<FunctionDecl>(Val: D))
638 os << "function";
639 else {
640 assert(isa<BlockDecl>(D));
641 os << "anonymous block";
642 }
643 os << '.';
644 }
645
646 return Loc;
647}
648
649static const Stmt *getEnclosingParent(const Stmt *S, const ParentMap &PM) {
650 if (isa<Expr>(Val: S) && PM.isConsumedExpr(E: cast<Expr>(Val: S)))
651 return PM.getParentIgnoreParens(S);
652
653 const Stmt *Parent = PM.getParentIgnoreParens(S);
654 if (!Parent)
655 return nullptr;
656
657 switch (Parent->getStmtClass()) {
658 case Stmt::ForStmtClass:
659 case Stmt::DoStmtClass:
660 case Stmt::WhileStmtClass:
661 case Stmt::ObjCForCollectionStmtClass:
662 case Stmt::CXXForRangeStmtClass:
663 return Parent;
664 default:
665 break;
666 }
667
668 return nullptr;
669}
670
671static PathDiagnosticLocation
672getEnclosingStmtLocation(const Stmt *S, const LocationContext *LC,
673 bool allowNestedContexts = false) {
674 if (!S)
675 return {};
676
677 const SourceManager &SMgr = LC->getDecl()->getASTContext().getSourceManager();
678
679 while (const Stmt *Parent = getEnclosingParent(S, PM: LC->getParentMap())) {
680 switch (Parent->getStmtClass()) {
681 case Stmt::BinaryOperatorClass: {
682 const auto *B = cast<BinaryOperator>(Val: Parent);
683 if (B->isLogicalOp())
684 return PathDiagnosticLocation(allowNestedContexts ? B : S, SMgr, LC);
685 break;
686 }
687 case Stmt::CompoundStmtClass:
688 case Stmt::StmtExprClass:
689 return PathDiagnosticLocation(S, SMgr, LC);
690 case Stmt::ChooseExprClass:
691 // Similar to '?' if we are referring to condition, just have the edge
692 // point to the entire choose expression.
693 if (allowNestedContexts || cast<ChooseExpr>(Val: Parent)->getCond() == S)
694 return PathDiagnosticLocation(Parent, SMgr, LC);
695 else
696 return PathDiagnosticLocation(S, SMgr, LC);
697 case Stmt::BinaryConditionalOperatorClass:
698 case Stmt::ConditionalOperatorClass:
699 // For '?', if we are referring to condition, just have the edge point
700 // to the entire '?' expression.
701 if (allowNestedContexts ||
702 cast<AbstractConditionalOperator>(Val: Parent)->getCond() == S)
703 return PathDiagnosticLocation(Parent, SMgr, LC);
704 else
705 return PathDiagnosticLocation(S, SMgr, LC);
706 case Stmt::CXXForRangeStmtClass:
707 if (cast<CXXForRangeStmt>(Val: Parent)->getBody() == S)
708 return PathDiagnosticLocation(S, SMgr, LC);
709 break;
710 case Stmt::DoStmtClass:
711 return PathDiagnosticLocation(S, SMgr, LC);
712 case Stmt::ForStmtClass:
713 if (cast<ForStmt>(Val: Parent)->getBody() == S)
714 return PathDiagnosticLocation(S, SMgr, LC);
715 break;
716 case Stmt::IfStmtClass:
717 if (cast<IfStmt>(Val: Parent)->getCond() != S)
718 return PathDiagnosticLocation(S, SMgr, LC);
719 break;
720 case Stmt::ObjCForCollectionStmtClass:
721 if (cast<ObjCForCollectionStmt>(Val: Parent)->getBody() == S)
722 return PathDiagnosticLocation(S, SMgr, LC);
723 break;
724 case Stmt::WhileStmtClass:
725 if (cast<WhileStmt>(Val: Parent)->getCond() != S)
726 return PathDiagnosticLocation(S, SMgr, LC);
727 break;
728 default:
729 break;
730 }
731
732 S = Parent;
733 }
734
735 assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
736
737 return PathDiagnosticLocation(S, SMgr, LC);
738}
739
740//===----------------------------------------------------------------------===//
741// "Minimal" path diagnostic generation algorithm.
742//===----------------------------------------------------------------------===//
743
744/// If the piece contains a special message, add it to all the call pieces on
745/// the active stack. For example, my_malloc allocated memory, so MallocChecker
746/// will construct an event at the call to malloc(), and add a stack hint that
747/// an allocated memory was returned. We'll use this hint to construct a message
748/// when returning from the call to my_malloc
749///
750/// void *my_malloc() { return malloc(sizeof(int)); }
751/// void fishy() {
752/// void *ptr = my_malloc(); // returned allocated memory
753/// } // leak
754void PathDiagnosticBuilder::updateStackPiecesWithMessage(
755 PathDiagnosticPieceRef P, const CallWithEntryStack &CallStack) const {
756 if (R->hasCallStackHint(Piece: P))
757 for (const auto &I : CallStack) {
758 PathDiagnosticCallPiece *CP = I.first;
759 const ExplodedNode *N = I.second;
760 std::string stackMsg = R->getCallStackMessage(Piece: P, N);
761
762 // The last message on the path to final bug is the most important
763 // one. Since we traverse the path backwards, do not add the message
764 // if one has been previously added.
765 if (!CP->hasCallStackMessage())
766 CP->setCallStackMessage(stackMsg);
767 }
768}
769
770static void CompactMacroExpandedPieces(PathPieces &path,
771 const SourceManager& SM);
772
773PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForSwitchOP(
774 const PathDiagnosticConstruct &C, const CFGBlock *Dst,
775 PathDiagnosticLocation &Start) const {
776
777 const SourceManager &SM = getSourceManager();
778 // Figure out what case arm we took.
779 std::string sbuf;
780 llvm::raw_string_ostream os(sbuf);
781 PathDiagnosticLocation End;
782
783 if (const Stmt *S = Dst->getLabel()) {
784 End = PathDiagnosticLocation(S, SM, C.getCurrLocationContext());
785
786 switch (S->getStmtClass()) {
787 default:
788 os << "No cases match in the switch statement. "
789 "Control jumps to line "
790 << End.asLocation().getExpansionLineNumber();
791 break;
792 case Stmt::DefaultStmtClass:
793 os << "Control jumps to the 'default' case at line "
794 << End.asLocation().getExpansionLineNumber();
795 break;
796
797 case Stmt::CaseStmtClass: {
798 os << "Control jumps to 'case ";
799 const auto *Case = cast<CaseStmt>(Val: S);
800 const Expr *LHS = Case->getLHS()->IgnoreParenImpCasts();
801
802 // Determine if it is an enum.
803 bool GetRawInt = true;
804
805 if (const auto *DR = dyn_cast<DeclRefExpr>(Val: LHS)) {
806 // FIXME: Maybe this should be an assertion. Are there cases
807 // were it is not an EnumConstantDecl?
808 const auto *D = dyn_cast<EnumConstantDecl>(Val: DR->getDecl());
809
810 if (D) {
811 GetRawInt = false;
812 os << *D;
813 }
814 }
815
816 if (GetRawInt)
817 os << LHS->EvaluateKnownConstInt(Ctx: getASTContext());
818
819 os << ":' at line " << End.asLocation().getExpansionLineNumber();
820 break;
821 }
822 }
823 } else {
824 os << "'Default' branch taken. ";
825 End = ExecutionContinues(os, C);
826 }
827 return std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf);
828}
829
830PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForGotoOP(
831 const PathDiagnosticConstruct &C, const Stmt *S,
832 PathDiagnosticLocation &Start) const {
833 std::string sbuf;
834 llvm::raw_string_ostream os(sbuf);
835 const PathDiagnosticLocation &End =
836 getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
837 os << "Control jumps to line " << End.asLocation().getExpansionLineNumber();
838 return std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args: End, args&: sbuf);
839}
840
841PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForBinaryOP(
842 const PathDiagnosticConstruct &C, const Stmt *T, const CFGBlock *Src,
843 const CFGBlock *Dst) const {
844
845 const SourceManager &SM = getSourceManager();
846
847 const auto *B = cast<BinaryOperator>(Val: T);
848 std::string sbuf;
849 llvm::raw_string_ostream os(sbuf);
850 os << "Left side of '";
851 PathDiagnosticLocation Start, End;
852
853 if (B->getOpcode() == BO_LAnd) {
854 os << "&&"
855 << "' is ";
856
857 if (*(Src->succ_begin() + 1) == Dst) {
858 os << "false";
859 End = PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
860 Start =
861 PathDiagnosticLocation::createOperatorLoc(BO: B, SM);
862 } else {
863 os << "true";
864 Start =
865 PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
866 End = ExecutionContinues(C);
867 }
868 } else {
869 assert(B->getOpcode() == BO_LOr);
870 os << "||"
871 << "' is ";
872
873 if (*(Src->succ_begin() + 1) == Dst) {
874 os << "false";
875 Start =
876 PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
877 End = ExecutionContinues(C);
878 } else {
879 os << "true";
880 End = PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
881 Start =
882 PathDiagnosticLocation::createOperatorLoc(BO: B, SM);
883 }
884 }
885 return std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf);
886}
887
888void PathDiagnosticBuilder::generateMinimalDiagForBlockEdge(
889 PathDiagnosticConstruct &C, BlockEdge BE) const {
890 const SourceManager &SM = getSourceManager();
891 const LocationContext *LC = C.getCurrLocationContext();
892 const CFGBlock *Src = BE.getSrc();
893 const CFGBlock *Dst = BE.getDst();
894 const Stmt *T = Src->getTerminatorStmt();
895 if (!T)
896 return;
897
898 auto Start = PathDiagnosticLocation::createBegin(S: T, SM, LAC: LC);
899 switch (T->getStmtClass()) {
900 default:
901 break;
902
903 case Stmt::GotoStmtClass:
904 case Stmt::IndirectGotoStmtClass: {
905 if (const Stmt *S = C.getCurrentNode()->getNextStmtForDiagnostics())
906 C.getActivePath().push_front(x: generateDiagForGotoOP(C, S, Start));
907 break;
908 }
909
910 case Stmt::SwitchStmtClass: {
911 C.getActivePath().push_front(x: generateDiagForSwitchOP(C, Dst, Start));
912 break;
913 }
914
915 case Stmt::BreakStmtClass:
916 case Stmt::ContinueStmtClass: {
917 std::string sbuf;
918 llvm::raw_string_ostream os(sbuf);
919 PathDiagnosticLocation End = ExecutionContinues(os, C);
920 C.getActivePath().push_front(
921 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
922 break;
923 }
924
925 // Determine control-flow for ternary '?'.
926 case Stmt::BinaryConditionalOperatorClass:
927 case Stmt::ConditionalOperatorClass: {
928 std::string sbuf;
929 llvm::raw_string_ostream os(sbuf);
930 os << "'?' condition is ";
931
932 if (*(Src->succ_begin() + 1) == Dst)
933 os << "false";
934 else
935 os << "true";
936
937 PathDiagnosticLocation End = ExecutionContinues(C);
938
939 if (const Stmt *S = End.asStmt())
940 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
941
942 C.getActivePath().push_front(
943 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
944 break;
945 }
946
947 // Determine control-flow for short-circuited '&&' and '||'.
948 case Stmt::BinaryOperatorClass: {
949 if (!C.supportsLogicalOpControlFlow())
950 break;
951
952 C.getActivePath().push_front(x: generateDiagForBinaryOP(C, T, Src, Dst));
953 break;
954 }
955
956 case Stmt::DoStmtClass:
957 if (*(Src->succ_begin()) == Dst) {
958 std::string sbuf;
959 llvm::raw_string_ostream os(sbuf);
960
961 os << "Loop condition is true. ";
962 PathDiagnosticLocation End = ExecutionContinues(os, C);
963
964 if (const Stmt *S = End.asStmt())
965 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
966
967 C.getActivePath().push_front(
968 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
969 } else {
970 PathDiagnosticLocation End = ExecutionContinues(C);
971
972 if (const Stmt *S = End.asStmt())
973 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
974
975 C.getActivePath().push_front(
976 x: std::make_shared<PathDiagnosticControlFlowPiece>(
977 args&: Start, args&: End, args: "Loop condition is false. Exiting loop"));
978 }
979 break;
980
981 case Stmt::WhileStmtClass:
982 case Stmt::ForStmtClass:
983 if (*(Src->succ_begin() + 1) == Dst) {
984 std::string sbuf;
985 llvm::raw_string_ostream os(sbuf);
986
987 os << "Loop condition is false. ";
988 PathDiagnosticLocation End = ExecutionContinues(os, C);
989 if (const Stmt *S = End.asStmt())
990 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
991
992 C.getActivePath().push_front(
993 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
994 } else {
995 PathDiagnosticLocation End = ExecutionContinues(C);
996 if (const Stmt *S = End.asStmt())
997 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
998
999 C.getActivePath().push_front(
1000 x: std::make_shared<PathDiagnosticControlFlowPiece>(
1001 args&: Start, args&: End, args: "Loop condition is true. Entering loop body"));
1002 }
1003
1004 break;
1005
1006 case Stmt::IfStmtClass: {
1007 PathDiagnosticLocation End = ExecutionContinues(C);
1008
1009 if (const Stmt *S = End.asStmt())
1010 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
1011
1012 if (*(Src->succ_begin() + 1) == Dst)
1013 C.getActivePath().push_front(
1014 x: std::make_shared<PathDiagnosticControlFlowPiece>(
1015 args&: Start, args&: End, args: "Taking false branch"));
1016 else
1017 C.getActivePath().push_front(
1018 x: std::make_shared<PathDiagnosticControlFlowPiece>(
1019 args&: Start, args&: End, args: "Taking true branch"));
1020
1021 break;
1022 }
1023 }
1024}
1025
1026//===----------------------------------------------------------------------===//
1027// Functions for determining if a loop was executed 0 times.
1028//===----------------------------------------------------------------------===//
1029
1030static bool isLoop(const Stmt *Term) {
1031 switch (Term->getStmtClass()) {
1032 case Stmt::ForStmtClass:
1033 case Stmt::WhileStmtClass:
1034 case Stmt::ObjCForCollectionStmtClass:
1035 case Stmt::CXXForRangeStmtClass:
1036 return true;
1037 default:
1038 // Note that we intentionally do not include do..while here.
1039 return false;
1040 }
1041}
1042
1043static bool isJumpToFalseBranch(const BlockEdge *BE) {
1044 const CFGBlock *Src = BE->getSrc();
1045 assert(Src->succ_size() == 2);
1046 return (*(Src->succ_begin()+1) == BE->getDst());
1047}
1048
1049static bool isContainedByStmt(const ParentMap &PM, const Stmt *S,
1050 const Stmt *SubS) {
1051 while (SubS) {
1052 if (SubS == S)
1053 return true;
1054 SubS = PM.getParent(S: SubS);
1055 }
1056 return false;
1057}
1058
1059static const Stmt *getStmtBeforeCond(const ParentMap &PM, const Stmt *Term,
1060 const ExplodedNode *N) {
1061 while (N) {
1062 std::optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>();
1063 if (SP) {
1064 const Stmt *S = SP->getStmt();
1065 if (!isContainedByStmt(PM, S: Term, SubS: S))
1066 return S;
1067 }
1068 N = N->getFirstPred();
1069 }
1070 return nullptr;
1071}
1072
1073static bool isInLoopBody(const ParentMap &PM, const Stmt *S, const Stmt *Term) {
1074 const Stmt *LoopBody = nullptr;
1075 switch (Term->getStmtClass()) {
1076 case Stmt::CXXForRangeStmtClass: {
1077 const auto *FR = cast<CXXForRangeStmt>(Val: Term);
1078 if (isContainedByStmt(PM, S: FR->getInc(), SubS: S))
1079 return true;
1080 if (isContainedByStmt(PM, S: FR->getLoopVarStmt(), SubS: S))
1081 return true;
1082 LoopBody = FR->getBody();
1083 break;
1084 }
1085 case Stmt::ForStmtClass: {
1086 const auto *FS = cast<ForStmt>(Val: Term);
1087 if (isContainedByStmt(PM, S: FS->getInc(), SubS: S))
1088 return true;
1089 LoopBody = FS->getBody();
1090 break;
1091 }
1092 case Stmt::ObjCForCollectionStmtClass: {
1093 const auto *FC = cast<ObjCForCollectionStmt>(Val: Term);
1094 LoopBody = FC->getBody();
1095 break;
1096 }
1097 case Stmt::WhileStmtClass:
1098 LoopBody = cast<WhileStmt>(Val: Term)->getBody();
1099 break;
1100 default:
1101 return false;
1102 }
1103 return isContainedByStmt(PM, S: LoopBody, SubS: S);
1104}
1105
1106/// Adds a sanitized control-flow diagnostic edge to a path.
1107static void addEdgeToPath(PathPieces &path,
1108 PathDiagnosticLocation &PrevLoc,
1109 PathDiagnosticLocation NewLoc) {
1110 if (!NewLoc.isValid())
1111 return;
1112
1113 SourceLocation NewLocL = NewLoc.asLocation();
1114 if (NewLocL.isInvalid())
1115 return;
1116
1117 if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) {
1118 PrevLoc = NewLoc;
1119 return;
1120 }
1121
1122 // Ignore self-edges, which occur when there are multiple nodes at the same
1123 // statement.
1124 if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt())
1125 return;
1126
1127 path.push_front(
1128 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: NewLoc, args&: PrevLoc));
1129 PrevLoc = NewLoc;
1130}
1131
1132/// A customized wrapper for CFGBlock::getTerminatorCondition()
1133/// which returns the element for ObjCForCollectionStmts.
1134static const Stmt *getTerminatorCondition(const CFGBlock *B) {
1135 const Stmt *S = B->getTerminatorCondition();
1136 if (const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(Val: S))
1137 return FS->getElement();
1138 return S;
1139}
1140
1141constexpr llvm::StringLiteral StrEnteringLoop = "Entering loop body";
1142constexpr llvm::StringLiteral StrLoopBodyZero = "Loop body executed 0 times";
1143constexpr llvm::StringLiteral StrLoopRangeEmpty =
1144 "Loop body skipped when range is empty";
1145constexpr llvm::StringLiteral StrLoopCollectionEmpty =
1146 "Loop body skipped when collection is empty";
1147
1148static std::unique_ptr<FilesToLineNumsMap>
1149findExecutedLines(const SourceManager &SM, const ExplodedNode *N);
1150
1151void PathDiagnosticBuilder::generatePathDiagnosticsForNode(
1152 PathDiagnosticConstruct &C, PathDiagnosticLocation &PrevLoc) const {
1153 ProgramPoint P = C.getCurrentNode()->getLocation();
1154 const SourceManager &SM = getSourceManager();
1155
1156 // Have we encountered an entrance to a call? It may be
1157 // the case that we have not encountered a matching
1158 // call exit before this point. This means that the path
1159 // terminated within the call itself.
1160 if (auto CE = P.getAs<CallEnter>()) {
1161
1162 if (C.shouldAddPathEdges()) {
1163 // Add an edge to the start of the function.
1164 const StackFrameContext *CalleeLC = CE->getCalleeContext();
1165 const Decl *D = CalleeLC->getDecl();
1166 // Add the edge only when the callee has body. We jump to the beginning
1167 // of the *declaration*, however we expect it to be followed by the
1168 // body. This isn't the case for autosynthesized property accessors in
1169 // Objective-C. No need for a similar extra check for CallExit points
1170 // because the exit edge comes from a statement (i.e. return),
1171 // not from declaration.
1172 if (D->hasBody())
1173 addEdgeToPath(path&: C.getActivePath(), PrevLoc,
1174 NewLoc: PathDiagnosticLocation::createBegin(D, SM));
1175 }
1176
1177 // Did we visit an entire call?
1178 bool VisitedEntireCall = C.PD->isWithinCall();
1179 C.PD->popActivePath();
1180
1181 PathDiagnosticCallPiece *Call;
1182 if (VisitedEntireCall) {
1183 Call = cast<PathDiagnosticCallPiece>(Val: C.getActivePath().front().get());
1184 } else {
1185 // The path terminated within a nested location context, create a new
1186 // call piece to encapsulate the rest of the path pieces.
1187 const Decl *Caller = CE->getLocationContext()->getDecl();
1188 Call = PathDiagnosticCallPiece::construct(pieces&: C.getActivePath(), caller: Caller);
1189 assert(C.getActivePath().size() == 1 &&
1190 C.getActivePath().front().get() == Call);
1191
1192 // Since we just transferred the path over to the call piece, reset the
1193 // mapping of the active path to the current location context.
1194 assert(C.isInLocCtxMap(&C.getActivePath()) &&
1195 "When we ascend to a previously unvisited call, the active path's "
1196 "address shouldn't change, but rather should be compacted into "
1197 "a single CallEvent!");
1198 C.updateLocCtxMap(Path: &C.getActivePath(), LC: C.getCurrLocationContext());
1199
1200 // Record the location context mapping for the path within the call.
1201 assert(!C.isInLocCtxMap(&Call->path) &&
1202 "When we ascend to a previously unvisited call, this must be the "
1203 "first time we encounter the caller context!");
1204 C.updateLocCtxMap(Path: &Call->path, LC: CE->getCalleeContext());
1205 }
1206 Call->setCallee(CE: *CE, SM);
1207
1208 // Update the previous location in the active path.
1209 PrevLoc = Call->getLocation();
1210
1211 if (!C.CallStack.empty()) {
1212 assert(C.CallStack.back().first == Call);
1213 C.CallStack.pop_back();
1214 }
1215 return;
1216 }
1217
1218 assert(C.getCurrLocationContext() == C.getLocationContextForActivePath() &&
1219 "The current position in the bug path is out of sync with the "
1220 "location context associated with the active path!");
1221
1222 // Have we encountered an exit from a function call?
1223 if (std::optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
1224
1225 // We are descending into a call (backwards). Construct
1226 // a new call piece to contain the path pieces for that call.
1227 auto Call = PathDiagnosticCallPiece::construct(CE: *CE, SM);
1228 // Record the mapping from call piece to LocationContext.
1229 assert(!C.isInLocCtxMap(&Call->path) &&
1230 "We just entered a call, this must've been the first time we "
1231 "encounter its context!");
1232 C.updateLocCtxMap(Path: &Call->path, LC: CE->getCalleeContext());
1233
1234 if (C.shouldAddPathEdges()) {
1235 // Add the edge to the return site.
1236 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: Call->callReturn);
1237 PrevLoc.invalidate();
1238 }
1239
1240 auto *P = Call.get();
1241 C.getActivePath().push_front(x: std::move(Call));
1242
1243 // Make the contents of the call the active path for now.
1244 C.PD->pushActivePath(p: &P->path);
1245 C.CallStack.push_back(Elt: CallWithEntry(P, C.getCurrentNode()));
1246 return;
1247 }
1248
1249 if (auto PS = P.getAs<PostStmt>()) {
1250 if (!C.shouldAddPathEdges())
1251 return;
1252
1253 // Add an edge. If this is an ObjCForCollectionStmt do
1254 // not add an edge here as it appears in the CFG both
1255 // as a terminator and as a terminator condition.
1256 if (!isa<ObjCForCollectionStmt>(Val: PS->getStmt())) {
1257 PathDiagnosticLocation L =
1258 PathDiagnosticLocation(PS->getStmt(), SM, C.getCurrLocationContext());
1259 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: L);
1260 }
1261
1262 } else if (auto BE = P.getAs<BlockEdge>()) {
1263
1264 if (C.shouldAddControlNotes()) {
1265 generateMinimalDiagForBlockEdge(C, BE: *BE);
1266 }
1267
1268 if (!C.shouldAddPathEdges()) {
1269 return;
1270 }
1271
1272 // Are we jumping to the head of a loop? Add a special diagnostic.
1273 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
1274 PathDiagnosticLocation L(Loop, SM, C.getCurrLocationContext());
1275 const Stmt *Body = nullptr;
1276
1277 if (const auto *FS = dyn_cast<ForStmt>(Val: Loop))
1278 Body = FS->getBody();
1279 else if (const auto *WS = dyn_cast<WhileStmt>(Val: Loop))
1280 Body = WS->getBody();
1281 else if (const auto *OFS = dyn_cast<ObjCForCollectionStmt>(Val: Loop)) {
1282 Body = OFS->getBody();
1283 } else if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Val: Loop)) {
1284 Body = FRS->getBody();
1285 }
1286 // do-while statements are explicitly excluded here
1287
1288 auto p = std::make_shared<PathDiagnosticEventPiece>(
1289 args&: L, args: "Looping back to the head of the loop");
1290 p->setPrunable(isPrunable: true);
1291
1292 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: p->getLocation());
1293 // We might've added a very similar control node already
1294 if (!C.shouldAddControlNotes()) {
1295 C.getActivePath().push_front(x: std::move(p));
1296 }
1297
1298 if (const auto *CS = dyn_cast_or_null<CompoundStmt>(Val: Body)) {
1299 addEdgeToPath(path&: C.getActivePath(), PrevLoc,
1300 NewLoc: PathDiagnosticLocation::createEndBrace(CS, SM));
1301 }
1302 }
1303
1304 const CFGBlock *BSrc = BE->getSrc();
1305 const ParentMap &PM = C.getParentMap();
1306
1307 if (const Stmt *Term = BSrc->getTerminatorStmt()) {
1308 // Are we jumping past the loop body without ever executing the
1309 // loop (because the condition was false)?
1310 if (isLoop(Term)) {
1311 const Stmt *TermCond = getTerminatorCondition(B: BSrc);
1312 bool IsInLoopBody = isInLoopBody(
1313 PM, S: getStmtBeforeCond(PM, Term: TermCond, N: C.getCurrentNode()), Term);
1314
1315 StringRef str;
1316
1317 if (isJumpToFalseBranch(BE: &*BE)) {
1318 if (!IsInLoopBody) {
1319 if (isa<ObjCForCollectionStmt>(Val: Term)) {
1320 str = StrLoopCollectionEmpty;
1321 } else if (isa<CXXForRangeStmt>(Val: Term)) {
1322 str = StrLoopRangeEmpty;
1323 } else {
1324 str = StrLoopBodyZero;
1325 }
1326 }
1327 } else {
1328 str = StrEnteringLoop;
1329 }
1330
1331 if (!str.empty()) {
1332 PathDiagnosticLocation L(TermCond ? TermCond : Term, SM,
1333 C.getCurrLocationContext());
1334 auto PE = std::make_shared<PathDiagnosticEventPiece>(args&: L, args&: str);
1335 PE->setPrunable(isPrunable: true);
1336 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: PE->getLocation());
1337
1338 // We might've added a very similar control node already
1339 if (!C.shouldAddControlNotes()) {
1340 C.getActivePath().push_front(x: std::move(PE));
1341 }
1342 }
1343 } else if (isa<BreakStmt, ContinueStmt, GotoStmt>(Val: Term)) {
1344 PathDiagnosticLocation L(Term, SM, C.getCurrLocationContext());
1345 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: L);
1346 }
1347 }
1348 }
1349}
1350
1351static std::unique_ptr<PathDiagnostic>
1352generateDiagnosticForBasicReport(const BasicBugReport *R,
1353 const Decl *AnalysisEntryPoint) {
1354 const BugType &BT = R->getBugType();
1355 return std::make_unique<PathDiagnostic>(
1356 args: BT.getCheckerName(), args: R->getDeclWithIssue(), args: BT.getDescription(),
1357 args: R->getDescription(), args: R->getShortDescription(/*UseFallback=*/false),
1358 args: BT.getCategory(), args: R->getUniqueingLocation(), args: R->getUniqueingDecl(),
1359 args&: AnalysisEntryPoint, args: std::make_unique<FilesToLineNumsMap>());
1360}
1361
1362static std::unique_ptr<PathDiagnostic>
1363generateEmptyDiagnosticForReport(const PathSensitiveBugReport *R,
1364 const SourceManager &SM,
1365 const Decl *AnalysisEntryPoint) {
1366 const BugType &BT = R->getBugType();
1367 return std::make_unique<PathDiagnostic>(
1368 args: BT.getCheckerName(), args: R->getDeclWithIssue(), args: BT.getDescription(),
1369 args: R->getDescription(), args: R->getShortDescription(/*UseFallback=*/false),
1370 args: BT.getCategory(), args: R->getUniqueingLocation(), args: R->getUniqueingDecl(),
1371 args&: AnalysisEntryPoint, args: findExecutedLines(SM, N: R->getErrorNode()));
1372}
1373
1374static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) {
1375 if (!S)
1376 return nullptr;
1377
1378 while (true) {
1379 S = PM.getParentIgnoreParens(S);
1380
1381 if (!S)
1382 break;
1383
1384 if (isa<FullExpr, CXXBindTemporaryExpr, SubstNonTypeTemplateParmExpr>(Val: S))
1385 continue;
1386
1387 break;
1388 }
1389
1390 return S;
1391}
1392
1393static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) {
1394 switch (S->getStmtClass()) {
1395 case Stmt::BinaryOperatorClass: {
1396 const auto *BO = cast<BinaryOperator>(Val: S);
1397 if (!BO->isLogicalOp())
1398 return false;
1399 return BO->getLHS() == Cond || BO->getRHS() == Cond;
1400 }
1401 case Stmt::IfStmtClass:
1402 return cast<IfStmt>(Val: S)->getCond() == Cond;
1403 case Stmt::ForStmtClass:
1404 return cast<ForStmt>(Val: S)->getCond() == Cond;
1405 case Stmt::WhileStmtClass:
1406 return cast<WhileStmt>(Val: S)->getCond() == Cond;
1407 case Stmt::DoStmtClass:
1408 return cast<DoStmt>(Val: S)->getCond() == Cond;
1409 case Stmt::ChooseExprClass:
1410 return cast<ChooseExpr>(Val: S)->getCond() == Cond;
1411 case Stmt::IndirectGotoStmtClass:
1412 return cast<IndirectGotoStmt>(Val: S)->getTarget() == Cond;
1413 case Stmt::SwitchStmtClass:
1414 return cast<SwitchStmt>(Val: S)->getCond() == Cond;
1415 case Stmt::BinaryConditionalOperatorClass:
1416 return cast<BinaryConditionalOperator>(Val: S)->getCond() == Cond;
1417 case Stmt::ConditionalOperatorClass: {
1418 const auto *CO = cast<ConditionalOperator>(Val: S);
1419 return CO->getCond() == Cond ||
1420 CO->getLHS() == Cond ||
1421 CO->getRHS() == Cond;
1422 }
1423 case Stmt::ObjCForCollectionStmtClass:
1424 return cast<ObjCForCollectionStmt>(Val: S)->getElement() == Cond;
1425 case Stmt::CXXForRangeStmtClass: {
1426 const auto *FRS = cast<CXXForRangeStmt>(Val: S);
1427 return FRS->getCond() == Cond || FRS->getRangeInit() == Cond;
1428 }
1429 default:
1430 return false;
1431 }
1432}
1433
1434static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) {
1435 if (const auto *FS = dyn_cast<ForStmt>(Val: FL))
1436 return FS->getInc() == S || FS->getInit() == S;
1437 if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Val: FL))
1438 return FRS->getInc() == S || FRS->getRangeStmt() == S ||
1439 FRS->getLoopVarStmt() || FRS->getRangeInit() == S;
1440 return false;
1441}
1442
1443using OptimizedCallsSet = llvm::DenseSet<const PathDiagnosticCallPiece *>;
1444
1445/// Adds synthetic edges from top-level statements to their subexpressions.
1446///
1447/// This avoids a "swoosh" effect, where an edge from a top-level statement A
1448/// points to a sub-expression B.1 that's not at the start of B. In these cases,
1449/// we'd like to see an edge from A to B, then another one from B to B.1.
1450static void addContextEdges(PathPieces &pieces, const LocationContext *LC) {
1451 const ParentMap &PM = LC->getParentMap();
1452 PathPieces::iterator Prev = pieces.end();
1453 for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E;
1454 Prev = I, ++I) {
1455 auto *Piece = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1456
1457 if (!Piece)
1458 continue;
1459
1460 PathDiagnosticLocation SrcLoc = Piece->getStartLocation();
1461 SmallVector<PathDiagnosticLocation, 4> SrcContexts;
1462
1463 PathDiagnosticLocation NextSrcContext = SrcLoc;
1464 const Stmt *InnerStmt = nullptr;
1465 while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) {
1466 SrcContexts.push_back(Elt: NextSrcContext);
1467 InnerStmt = NextSrcContext.asStmt();
1468 NextSrcContext = getEnclosingStmtLocation(S: InnerStmt, LC,
1469 /*allowNested=*/allowNestedContexts: true);
1470 }
1471
1472 // Repeatedly split the edge as necessary.
1473 // This is important for nested logical expressions (||, &&, ?:) where we
1474 // want to show all the levels of context.
1475 while (true) {
1476 const Stmt *Dst = Piece->getEndLocation().getStmtOrNull();
1477
1478 // We are looking at an edge. Is the destination within a larger
1479 // expression?
1480 PathDiagnosticLocation DstContext =
1481 getEnclosingStmtLocation(S: Dst, LC, /*allowNested=*/allowNestedContexts: true);
1482 if (!DstContext.isValid() || DstContext.asStmt() == Dst)
1483 break;
1484
1485 // If the source is in the same context, we're already good.
1486 if (llvm::is_contained(Range&: SrcContexts, Element: DstContext))
1487 break;
1488
1489 // Update the subexpression node to point to the context edge.
1490 Piece->setStartLocation(DstContext);
1491
1492 // Try to extend the previous edge if it's at the same level as the source
1493 // context.
1494 if (Prev != E) {
1495 auto *PrevPiece = dyn_cast<PathDiagnosticControlFlowPiece>(Val: Prev->get());
1496
1497 if (PrevPiece) {
1498 if (const Stmt *PrevSrc =
1499 PrevPiece->getStartLocation().getStmtOrNull()) {
1500 const Stmt *PrevSrcParent = getStmtParent(S: PrevSrc, PM);
1501 if (PrevSrcParent ==
1502 getStmtParent(S: DstContext.getStmtOrNull(), PM)) {
1503 PrevPiece->setEndLocation(DstContext);
1504 break;
1505 }
1506 }
1507 }
1508 }
1509
1510 // Otherwise, split the current edge into a context edge and a
1511 // subexpression edge. Note that the context statement may itself have
1512 // context.
1513 auto P =
1514 std::make_shared<PathDiagnosticControlFlowPiece>(args&: SrcLoc, args&: DstContext);
1515 Piece = P.get();
1516 I = pieces.insert(position: I, x: std::move(P));
1517 }
1518 }
1519}
1520
1521/// Move edges from a branch condition to a branch target
1522/// when the condition is simple.
1523///
1524/// This restructures some of the work of addContextEdges. That function
1525/// creates edges this may destroy, but they work together to create a more
1526/// aesthetically set of edges around branches. After the call to
1527/// addContextEdges, we may have (1) an edge to the branch, (2) an edge from
1528/// the branch to the branch condition, and (3) an edge from the branch
1529/// condition to the branch target. We keep (1), but may wish to remove (2)
1530/// and move the source of (3) to the branch if the branch condition is simple.
1531static void simplifySimpleBranches(PathPieces &pieces) {
1532 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) {
1533 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1534
1535 if (!PieceI)
1536 continue;
1537
1538 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1539 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1540
1541 if (!s1Start || !s1End)
1542 continue;
1543
1544 PathPieces::iterator NextI = I; ++NextI;
1545 if (NextI == E)
1546 break;
1547
1548 PathDiagnosticControlFlowPiece *PieceNextI = nullptr;
1549
1550 while (true) {
1551 if (NextI == E)
1552 break;
1553
1554 const auto *EV = dyn_cast<PathDiagnosticEventPiece>(Val: NextI->get());
1555 if (EV) {
1556 StringRef S = EV->getString();
1557 if (S == StrEnteringLoop || S == StrLoopBodyZero ||
1558 S == StrLoopCollectionEmpty || S == StrLoopRangeEmpty) {
1559 ++NextI;
1560 continue;
1561 }
1562 break;
1563 }
1564
1565 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1566 break;
1567 }
1568
1569 if (!PieceNextI)
1570 continue;
1571
1572 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1573 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1574
1575 if (!s2Start || !s2End || s1End != s2Start)
1576 continue;
1577
1578 // We only perform this transformation for specific branch kinds.
1579 // We don't want to do this for do..while, for example.
1580 if (!isa<ForStmt, WhileStmt, IfStmt, ObjCForCollectionStmt,
1581 CXXForRangeStmt>(Val: s1Start))
1582 continue;
1583
1584 // Is s1End the branch condition?
1585 if (!isConditionForTerminator(S: s1Start, Cond: s1End))
1586 continue;
1587
1588 // Perform the hoisting by eliminating (2) and changing the start
1589 // location of (3).
1590 PieceNextI->setStartLocation(PieceI->getStartLocation());
1591 I = pieces.erase(position: I);
1592 }
1593}
1594
1595/// Returns the number of bytes in the given (character-based) SourceRange.
1596///
1597/// If the locations in the range are not on the same line, returns
1598/// std::nullopt.
1599///
1600/// Note that this does not do a precise user-visible character or column count.
1601static std::optional<size_t> getLengthOnSingleLine(const SourceManager &SM,
1602 SourceRange Range) {
1603 SourceRange ExpansionRange(SM.getExpansionLoc(Loc: Range.getBegin()),
1604 SM.getExpansionRange(Loc: Range.getEnd()).getEnd());
1605
1606 FileID FID = SM.getFileID(SpellingLoc: ExpansionRange.getBegin());
1607 if (FID != SM.getFileID(SpellingLoc: ExpansionRange.getEnd()))
1608 return std::nullopt;
1609
1610 std::optional<MemoryBufferRef> Buffer = SM.getBufferOrNone(FID);
1611 if (!Buffer)
1612 return std::nullopt;
1613
1614 unsigned BeginOffset = SM.getFileOffset(SpellingLoc: ExpansionRange.getBegin());
1615 unsigned EndOffset = SM.getFileOffset(SpellingLoc: ExpansionRange.getEnd());
1616 StringRef Snippet = Buffer->getBuffer().slice(Start: BeginOffset, End: EndOffset);
1617
1618 // We're searching the raw bytes of the buffer here, which might include
1619 // escaped newlines and such. That's okay; we're trying to decide whether the
1620 // SourceRange is covering a large or small amount of space in the user's
1621 // editor.
1622 if (Snippet.find_first_of(Chars: "\r\n") != StringRef::npos)
1623 return std::nullopt;
1624
1625 // This isn't Unicode-aware, but it doesn't need to be.
1626 return Snippet.size();
1627}
1628
1629/// \sa getLengthOnSingleLine(SourceManager, SourceRange)
1630static std::optional<size_t> getLengthOnSingleLine(const SourceManager &SM,
1631 const Stmt *S) {
1632 return getLengthOnSingleLine(SM, Range: S->getSourceRange());
1633}
1634
1635/// Eliminate two-edge cycles created by addContextEdges().
1636///
1637/// Once all the context edges are in place, there are plenty of cases where
1638/// there's a single edge from a top-level statement to a subexpression,
1639/// followed by a single path note, and then a reverse edge to get back out to
1640/// the top level. If the statement is simple enough, the subexpression edges
1641/// just add noise and make it harder to understand what's going on.
1642///
1643/// This function only removes edges in pairs, because removing only one edge
1644/// might leave other edges dangling.
1645///
1646/// This will not remove edges in more complicated situations:
1647/// - if there is more than one "hop" leading to or from a subexpression.
1648/// - if there is an inlined call between the edges instead of a single event.
1649/// - if the whole statement is large enough that having subexpression arrows
1650/// might be helpful.
1651static void removeContextCycles(PathPieces &Path, const SourceManager &SM) {
1652 for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) {
1653 // Pattern match the current piece and its successor.
1654 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1655
1656 if (!PieceI) {
1657 ++I;
1658 continue;
1659 }
1660
1661 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1662 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1663
1664 PathPieces::iterator NextI = I; ++NextI;
1665 if (NextI == E)
1666 break;
1667
1668 const auto *PieceNextI =
1669 dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1670
1671 if (!PieceNextI) {
1672 if (isa<PathDiagnosticEventPiece>(Val: NextI->get())) {
1673 ++NextI;
1674 if (NextI == E)
1675 break;
1676 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1677 }
1678
1679 if (!PieceNextI) {
1680 ++I;
1681 continue;
1682 }
1683 }
1684
1685 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1686 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1687
1688 if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) {
1689 const size_t MAX_SHORT_LINE_LENGTH = 80;
1690 std::optional<size_t> s1Length = getLengthOnSingleLine(SM, S: s1Start);
1691 if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) {
1692 std::optional<size_t> s2Length = getLengthOnSingleLine(SM, S: s2Start);
1693 if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) {
1694 Path.erase(position: I);
1695 I = Path.erase(position: NextI);
1696 continue;
1697 }
1698 }
1699 }
1700
1701 ++I;
1702 }
1703}
1704
1705/// Return true if X is contained by Y.
1706static bool lexicalContains(const ParentMap &PM, const Stmt *X, const Stmt *Y) {
1707 while (X) {
1708 if (X == Y)
1709 return true;
1710 X = PM.getParent(S: X);
1711 }
1712 return false;
1713}
1714
1715// Remove short edges on the same line less than 3 columns in difference.
1716static void removePunyEdges(PathPieces &path, const SourceManager &SM,
1717 const ParentMap &PM) {
1718 bool erased = false;
1719
1720 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E;
1721 erased ? I : ++I) {
1722 erased = false;
1723
1724 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1725
1726 if (!PieceI)
1727 continue;
1728
1729 const Stmt *start = PieceI->getStartLocation().getStmtOrNull();
1730 const Stmt *end = PieceI->getEndLocation().getStmtOrNull();
1731
1732 if (!start || !end)
1733 continue;
1734
1735 const Stmt *endParent = PM.getParent(S: end);
1736 if (!endParent)
1737 continue;
1738
1739 if (isConditionForTerminator(S: end, Cond: endParent))
1740 continue;
1741
1742 SourceLocation FirstLoc = start->getBeginLoc();
1743 SourceLocation SecondLoc = end->getBeginLoc();
1744
1745 if (!SM.isWrittenInSameFile(Loc1: FirstLoc, Loc2: SecondLoc))
1746 continue;
1747 if (SM.isBeforeInTranslationUnit(LHS: SecondLoc, RHS: FirstLoc))
1748 std::swap(a&: SecondLoc, b&: FirstLoc);
1749
1750 SourceRange EdgeRange(FirstLoc, SecondLoc);
1751 std::optional<size_t> ByteWidth = getLengthOnSingleLine(SM, Range: EdgeRange);
1752
1753 // If the statements are on different lines, continue.
1754 if (!ByteWidth)
1755 continue;
1756
1757 const size_t MAX_PUNY_EDGE_LENGTH = 2;
1758 if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) {
1759 // FIXME: There are enough /bytes/ between the endpoints of the edge, but
1760 // there might not be enough /columns/. A proper user-visible column count
1761 // is probably too expensive, though.
1762 I = path.erase(position: I);
1763 erased = true;
1764 continue;
1765 }
1766 }
1767}
1768
1769static void removeIdenticalEvents(PathPieces &path) {
1770 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) {
1771 const auto *PieceI = dyn_cast<PathDiagnosticEventPiece>(Val: I->get());
1772
1773 if (!PieceI)
1774 continue;
1775
1776 PathPieces::iterator NextI = I; ++NextI;
1777 if (NextI == E)
1778 return;
1779
1780 const auto *PieceNextI = dyn_cast<PathDiagnosticEventPiece>(Val: NextI->get());
1781
1782 if (!PieceNextI)
1783 continue;
1784
1785 // Erase the second piece if it has the same exact message text.
1786 if (PieceI->getString() == PieceNextI->getString()) {
1787 path.erase(position: NextI);
1788 }
1789 }
1790}
1791
1792static bool optimizeEdges(const PathDiagnosticConstruct &C, PathPieces &path,
1793 OptimizedCallsSet &OCS) {
1794 bool hasChanges = false;
1795 const LocationContext *LC = C.getLocationContextFor(Path: &path);
1796 assert(LC);
1797 const ParentMap &PM = LC->getParentMap();
1798 const SourceManager &SM = C.getSourceManager();
1799
1800 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
1801 // Optimize subpaths.
1802 if (auto *CallI = dyn_cast<PathDiagnosticCallPiece>(Val: I->get())) {
1803 // Record the fact that a call has been optimized so we only do the
1804 // effort once.
1805 if (!OCS.count(V: CallI)) {
1806 while (optimizeEdges(C, path&: CallI->path, OCS)) {
1807 }
1808 OCS.insert(V: CallI);
1809 }
1810 ++I;
1811 continue;
1812 }
1813
1814 // Pattern match the current piece and its successor.
1815 auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1816
1817 if (!PieceI) {
1818 ++I;
1819 continue;
1820 }
1821
1822 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1823 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1824 const Stmt *level1 = getStmtParent(S: s1Start, PM);
1825 const Stmt *level2 = getStmtParent(S: s1End, PM);
1826
1827 PathPieces::iterator NextI = I; ++NextI;
1828 if (NextI == E)
1829 break;
1830
1831 const auto *PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1832
1833 if (!PieceNextI) {
1834 ++I;
1835 continue;
1836 }
1837
1838 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1839 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1840 const Stmt *level3 = getStmtParent(S: s2Start, PM);
1841 const Stmt *level4 = getStmtParent(S: s2End, PM);
1842
1843 // Rule I.
1844 //
1845 // If we have two consecutive control edges whose end/begin locations
1846 // are at the same level (e.g. statements or top-level expressions within
1847 // a compound statement, or siblings share a single ancestor expression),
1848 // then merge them if they have no interesting intermediate event.
1849 //
1850 // For example:
1851 //
1852 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common
1853 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements.
1854 //
1855 // NOTE: this will be limited later in cases where we add barriers
1856 // to prevent this optimization.
1857 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) {
1858 PieceI->setEndLocation(PieceNextI->getEndLocation());
1859 path.erase(position: NextI);
1860 hasChanges = true;
1861 continue;
1862 }
1863
1864 // Rule II.
1865 //
1866 // Eliminate edges between subexpressions and parent expressions
1867 // when the subexpression is consumed.
1868 //
1869 // NOTE: this will be limited later in cases where we add barriers
1870 // to prevent this optimization.
1871 if (s1End && s1End == s2Start && level2) {
1872 bool removeEdge = false;
1873 // Remove edges into the increment or initialization of a
1874 // loop that have no interleaving event. This means that
1875 // they aren't interesting.
1876 if (isIncrementOrInitInForLoop(S: s1End, FL: level2))
1877 removeEdge = true;
1878 // Next only consider edges that are not anchored on
1879 // the condition of a terminator. This are intermediate edges
1880 // that we might want to trim.
1881 else if (!isConditionForTerminator(S: level2, Cond: s1End)) {
1882 // Trim edges on expressions that are consumed by
1883 // the parent expression.
1884 if (isa<Expr>(Val: s1End) && PM.isConsumedExpr(E: cast<Expr>(Val: s1End))) {
1885 removeEdge = true;
1886 }
1887 // Trim edges where a lexical containment doesn't exist.
1888 // For example:
1889 //
1890 // X -> Y -> Z
1891 //
1892 // If 'Z' lexically contains Y (it is an ancestor) and
1893 // 'X' does not lexically contain Y (it is a descendant OR
1894 // it has no lexical relationship at all) then trim.
1895 //
1896 // This can eliminate edges where we dive into a subexpression
1897 // and then pop back out, etc.
1898 else if (s1Start && s2End &&
1899 lexicalContains(PM, X: s2Start, Y: s2End) &&
1900 !lexicalContains(PM, X: s1End, Y: s1Start)) {
1901 removeEdge = true;
1902 }
1903 // Trim edges from a subexpression back to the top level if the
1904 // subexpression is on a different line.
1905 //
1906 // A.1 -> A -> B
1907 // becomes
1908 // A.1 -> B
1909 //
1910 // These edges just look ugly and don't usually add anything.
1911 else if (s1Start && s2End &&
1912 lexicalContains(PM, X: s1Start, Y: s1End)) {
1913 SourceRange EdgeRange(PieceI->getEndLocation().asLocation(),
1914 PieceI->getStartLocation().asLocation());
1915 if (!getLengthOnSingleLine(SM, Range: EdgeRange))
1916 removeEdge = true;
1917 }
1918 }
1919
1920 if (removeEdge) {
1921 PieceI->setEndLocation(PieceNextI->getEndLocation());
1922 path.erase(position: NextI);
1923 hasChanges = true;
1924 continue;
1925 }
1926 }
1927
1928 // Optimize edges for ObjC fast-enumeration loops.
1929 //
1930 // (X -> collection) -> (collection -> element)
1931 //
1932 // becomes:
1933 //
1934 // (X -> element)
1935 if (s1End == s2Start) {
1936 const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(Val: level3);
1937 if (FS && FS->getCollection()->IgnoreParens() == s2Start &&
1938 s2End == FS->getElement()) {
1939 PieceI->setEndLocation(PieceNextI->getEndLocation());
1940 path.erase(position: NextI);
1941 hasChanges = true;
1942 continue;
1943 }
1944 }
1945
1946 // No changes at this index? Move to the next one.
1947 ++I;
1948 }
1949
1950 if (!hasChanges) {
1951 // Adjust edges into subexpressions to make them more uniform
1952 // and aesthetically pleasing.
1953 addContextEdges(pieces&: path, LC);
1954 // Remove "cyclical" edges that include one or more context edges.
1955 removeContextCycles(Path&: path, SM);
1956 // Hoist edges originating from branch conditions to branches
1957 // for simple branches.
1958 simplifySimpleBranches(pieces&: path);
1959 // Remove any puny edges left over after primary optimization pass.
1960 removePunyEdges(path, SM, PM);
1961 // Remove identical events.
1962 removeIdenticalEvents(path);
1963 }
1964
1965 return hasChanges;
1966}
1967
1968/// Drop the very first edge in a path, which should be a function entry edge.
1969///
1970/// If the first edge is not a function entry edge (say, because the first
1971/// statement had an invalid source location), this function does nothing.
1972// FIXME: We should just generate invalid edges anyway and have the optimizer
1973// deal with them.
1974static void dropFunctionEntryEdge(const PathDiagnosticConstruct &C,
1975 PathPieces &Path) {
1976 const auto *FirstEdge =
1977 dyn_cast<PathDiagnosticControlFlowPiece>(Val: Path.front().get());
1978 if (!FirstEdge)
1979 return;
1980
1981 const Decl *D = C.getLocationContextFor(Path: &Path)->getDecl();
1982 PathDiagnosticLocation EntryLoc =
1983 PathDiagnosticLocation::createBegin(D, SM: C.getSourceManager());
1984 if (FirstEdge->getStartLocation() != EntryLoc)
1985 return;
1986
1987 Path.pop_front();
1988}
1989
1990/// Populate executes lines with lines containing at least one diagnostics.
1991static void updateExecutedLinesWithDiagnosticPieces(PathDiagnostic &PD) {
1992
1993 PathPieces path = PD.path.flatten(/*ShouldFlattenMacros=*/true);
1994 FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines();
1995
1996 for (const auto &P : path) {
1997 FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc();
1998 FileID FID = Loc.getFileID();
1999 unsigned LineNo = Loc.getLineNumber();
2000 assert(FID.isValid());
2001 ExecutedLines[FID].insert(x: LineNo);
2002 }
2003}
2004
2005PathDiagnosticConstruct::PathDiagnosticConstruct(
2006 const PathDiagnosticConsumer *PDC, const ExplodedNode *ErrorNode,
2007 const PathSensitiveBugReport *R, const Decl *AnalysisEntryPoint)
2008 : Consumer(PDC), CurrentNode(ErrorNode),
2009 SM(CurrentNode->getCodeDecl().getASTContext().getSourceManager()),
2010 PD(generateEmptyDiagnosticForReport(R, SM: getSourceManager(),
2011 AnalysisEntryPoint)) {
2012 LCM[&PD->getActivePath()] = ErrorNode->getLocationContext();
2013}
2014
2015PathDiagnosticBuilder::PathDiagnosticBuilder(
2016 BugReporterContext BRC, std::unique_ptr<ExplodedGraph> BugPath,
2017 PathSensitiveBugReport *r, const ExplodedNode *ErrorNode,
2018 std::unique_ptr<VisitorsDiagnosticsTy> VisitorsDiagnostics)
2019 : BugReporterContext(BRC), BugPath(std::move(BugPath)), R(r),
2020 ErrorNode(ErrorNode),
2021 VisitorsDiagnostics(std::move(VisitorsDiagnostics)) {}
2022
2023std::unique_ptr<PathDiagnostic>
2024PathDiagnosticBuilder::generate(const PathDiagnosticConsumer *PDC) const {
2025 const Decl *EntryPoint = getBugReporter().getAnalysisEntryPoint();
2026 PathDiagnosticConstruct Construct(PDC, ErrorNode, R, EntryPoint);
2027
2028 const SourceManager &SM = getSourceManager();
2029 const AnalyzerOptions &Opts = getAnalyzerOptions();
2030
2031 if (!PDC->shouldGenerateDiagnostics())
2032 return generateEmptyDiagnosticForReport(R, SM: getSourceManager(), AnalysisEntryPoint: EntryPoint);
2033
2034 // Construct the final (warning) event for the bug report.
2035 auto EndNotes = VisitorsDiagnostics->find(Val: ErrorNode);
2036 PathDiagnosticPieceRef LastPiece;
2037 if (EndNotes != VisitorsDiagnostics->end()) {
2038 assert(!EndNotes->second.empty());
2039 LastPiece = EndNotes->second[0];
2040 } else {
2041 LastPiece = BugReporterVisitor::getDefaultEndPath(BRC: *this, N: ErrorNode,
2042 BR: *getBugReport());
2043 }
2044 Construct.PD->setEndOfPath(LastPiece);
2045
2046 PathDiagnosticLocation PrevLoc = Construct.PD->getLocation();
2047 // From the error node to the root, ascend the bug path and construct the bug
2048 // report.
2049 while (Construct.ascendToPrevNode()) {
2050 generatePathDiagnosticsForNode(C&: Construct, PrevLoc);
2051
2052 auto VisitorNotes = VisitorsDiagnostics->find(Val: Construct.getCurrentNode());
2053 if (VisitorNotes == VisitorsDiagnostics->end())
2054 continue;
2055
2056 // This is a workaround due to inability to put shared PathDiagnosticPiece
2057 // into a FoldingSet.
2058 std::set<llvm::FoldingSetNodeID> DeduplicationSet;
2059
2060 // Add pieces from custom visitors.
2061 for (const PathDiagnosticPieceRef &Note : VisitorNotes->second) {
2062 llvm::FoldingSetNodeID ID;
2063 Note->Profile(ID);
2064 if (!DeduplicationSet.insert(x: ID).second)
2065 continue;
2066
2067 if (PDC->shouldAddPathEdges())
2068 addEdgeToPath(path&: Construct.getActivePath(), PrevLoc, NewLoc: Note->getLocation());
2069 updateStackPiecesWithMessage(P: Note, CallStack: Construct.CallStack);
2070 Construct.getActivePath().push_front(x: Note);
2071 }
2072 }
2073
2074 if (PDC->shouldAddPathEdges()) {
2075 // Add an edge to the start of the function.
2076 // We'll prune it out later, but it helps make diagnostics more uniform.
2077 const StackFrameContext *CalleeLC =
2078 Construct.getLocationContextForActivePath()->getStackFrame();
2079 const Decl *D = CalleeLC->getDecl();
2080 addEdgeToPath(path&: Construct.getActivePath(), PrevLoc,
2081 NewLoc: PathDiagnosticLocation::createBegin(D, SM));
2082 }
2083
2084
2085 // Finally, prune the diagnostic path of uninteresting stuff.
2086 if (!Construct.PD->path.empty()) {
2087 if (R->shouldPrunePath() && Opts.ShouldPrunePaths) {
2088 bool stillHasNotes =
2089 removeUnneededCalls(C: Construct, pieces&: Construct.getMutablePieces(), R);
2090 assert(stillHasNotes);
2091 (void)stillHasNotes;
2092 }
2093
2094 // Remove pop-up notes if needed.
2095 if (!Opts.ShouldAddPopUpNotes)
2096 removePopUpNotes(Path&: Construct.getMutablePieces());
2097
2098 // Redirect all call pieces to have valid locations.
2099 adjustCallLocations(Pieces&: Construct.getMutablePieces());
2100 removePiecesWithInvalidLocations(Pieces&: Construct.getMutablePieces());
2101
2102 if (PDC->shouldAddPathEdges()) {
2103
2104 // Reduce the number of edges from a very conservative set
2105 // to an aesthetically pleasing subset that conveys the
2106 // necessary information.
2107 OptimizedCallsSet OCS;
2108 while (optimizeEdges(C: Construct, path&: Construct.getMutablePieces(), OCS)) {
2109 }
2110
2111 // Drop the very first function-entry edge. It's not really necessary
2112 // for top-level functions.
2113 dropFunctionEntryEdge(C: Construct, Path&: Construct.getMutablePieces());
2114 }
2115
2116 // Remove messages that are basically the same, and edges that may not
2117 // make sense.
2118 // We have to do this after edge optimization in the Extensive mode.
2119 removeRedundantMsgs(path&: Construct.getMutablePieces());
2120 removeEdgesToDefaultInitializers(Pieces&: Construct.getMutablePieces());
2121 }
2122
2123 if (Opts.ShouldDisplayMacroExpansions)
2124 CompactMacroExpandedPieces(path&: Construct.getMutablePieces(), SM);
2125
2126 return std::move(Construct.PD);
2127}
2128
2129//===----------------------------------------------------------------------===//
2130// Methods for BugType and subclasses.
2131//===----------------------------------------------------------------------===//
2132
2133void BugType::anchor() {}
2134
2135//===----------------------------------------------------------------------===//
2136// Methods for BugReport and subclasses.
2137//===----------------------------------------------------------------------===//
2138
2139LLVM_ATTRIBUTE_USED static bool
2140isDependency(const CheckerRegistryData &Registry, StringRef CheckerName) {
2141 for (const std::pair<StringRef, StringRef> &Pair : Registry.Dependencies) {
2142 if (Pair.second == CheckerName)
2143 return true;
2144 }
2145 return false;
2146}
2147
2148LLVM_ATTRIBUTE_USED static bool isHidden(const CheckerRegistryData &Registry,
2149 StringRef CheckerName) {
2150 for (const CheckerInfo &Checker : Registry.Checkers) {
2151 if (Checker.FullName == CheckerName)
2152 return Checker.IsHidden;
2153 }
2154 llvm_unreachable(
2155 "Checker name not found in CheckerRegistry -- did you retrieve it "
2156 "correctly from CheckerManager::getCurrentCheckerName?");
2157}
2158
2159PathSensitiveBugReport::PathSensitiveBugReport(
2160 const BugType &bt, StringRef shortDesc, StringRef desc,
2161 const ExplodedNode *errorNode, PathDiagnosticLocation LocationToUnique,
2162 const Decl *DeclToUnique)
2163 : BugReport(Kind::PathSensitive, bt, shortDesc, desc), ErrorNode(errorNode),
2164 ErrorNodeRange(getStmt() ? getStmt()->getSourceRange() : SourceRange()),
2165 UniqueingLocation(LocationToUnique), UniqueingDecl(DeclToUnique) {
2166 assert(ErrorNode && "The error node must be non-null!");
2167 assert(!isDependency(ErrorNode->getState()
2168 ->getAnalysisManager()
2169 .getCheckerManager()
2170 ->getCheckerRegistryData(),
2171 bt.getCheckerName()) &&
2172 "Some checkers depend on this one! We don't allow dependency "
2173 "checkers to emit warnings, because checkers should depend on "
2174 "*modeling*, not *diagnostics*.");
2175
2176 assert((bt.getCheckerName().starts_with("debug") ||
2177 !isHidden(ErrorNode->getState()
2178 ->getAnalysisManager()
2179 .getCheckerManager()
2180 ->getCheckerRegistryData(),
2181 bt.getCheckerName())) &&
2182 "Hidden checkers musn't emit diagnostics as they are by definition "
2183 "non-user facing!");
2184}
2185
2186void PathSensitiveBugReport::addVisitor(
2187 std::unique_ptr<BugReporterVisitor> visitor) {
2188 if (!visitor)
2189 return;
2190
2191 llvm::FoldingSetNodeID ID;
2192 visitor->Profile(ID);
2193
2194 void *InsertPos = nullptr;
2195 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
2196 return;
2197 }
2198
2199 Callbacks.push_back(Elt: std::move(visitor));
2200}
2201
2202void PathSensitiveBugReport::clearVisitors() {
2203 Callbacks.clear();
2204}
2205
2206const Decl *PathSensitiveBugReport::getDeclWithIssue() const {
2207 const ExplodedNode *N = getErrorNode();
2208 if (!N)
2209 return nullptr;
2210
2211 const LocationContext *LC = N->getLocationContext();
2212 return LC->getStackFrame()->getDecl();
2213}
2214
2215void BasicBugReport::Profile(llvm::FoldingSetNodeID& hash) const {
2216 hash.AddInteger(I: static_cast<int>(getKind()));
2217 hash.AddPointer(Ptr: &BT);
2218 hash.AddString(String: getShortDescription());
2219 assert(Location.isValid());
2220 Location.Profile(ID&: hash);
2221
2222 for (SourceRange range : Ranges) {
2223 if (!range.isValid())
2224 continue;
2225 hash.Add(x: range.getBegin());
2226 hash.Add(x: range.getEnd());
2227 }
2228}
2229
2230void PathSensitiveBugReport::Profile(llvm::FoldingSetNodeID &hash) const {
2231 hash.AddInteger(I: static_cast<int>(getKind()));
2232 hash.AddPointer(Ptr: &BT);
2233 hash.AddString(String: getShortDescription());
2234 PathDiagnosticLocation UL = getUniqueingLocation();
2235 if (UL.isValid()) {
2236 UL.Profile(ID&: hash);
2237 } else {
2238 // TODO: The statement may be null if the report was emitted before any
2239 // statements were executed. In particular, some checkers by design
2240 // occasionally emit their reports in empty functions (that have no
2241 // statements in their body). Do we profile correctly in this case?
2242 hash.AddPointer(Ptr: ErrorNode->getCurrentOrPreviousStmtForDiagnostics());
2243 }
2244
2245 for (SourceRange range : Ranges) {
2246 if (!range.isValid())
2247 continue;
2248 hash.Add(x: range.getBegin());
2249 hash.Add(x: range.getEnd());
2250 }
2251}
2252
2253template <class T>
2254static void insertToInterestingnessMap(
2255 llvm::DenseMap<T, bugreporter::TrackingKind> &InterestingnessMap, T Val,
2256 bugreporter::TrackingKind TKind) {
2257 auto Result = InterestingnessMap.insert({Val, TKind});
2258
2259 if (Result.second)
2260 return;
2261
2262 // Even if this symbol/region was already marked as interesting as a
2263 // condition, if we later mark it as interesting again but with
2264 // thorough tracking, overwrite it. Entities marked with thorough
2265 // interestiness are the most important (or most interesting, if you will),
2266 // and we wouldn't like to downplay their importance.
2267
2268 switch (TKind) {
2269 case bugreporter::TrackingKind::Thorough:
2270 Result.first->getSecond() = bugreporter::TrackingKind::Thorough;
2271 return;
2272 case bugreporter::TrackingKind::Condition:
2273 return;
2274 }
2275
2276 llvm_unreachable(
2277 "BugReport::markInteresting currently can only handle 2 different "
2278 "tracking kinds! Please define what tracking kind should this entitiy"
2279 "have, if it was already marked as interesting with a different kind!");
2280}
2281
2282void PathSensitiveBugReport::markInteresting(SymbolRef sym,
2283 bugreporter::TrackingKind TKind) {
2284 if (!sym)
2285 return;
2286
2287 insertToInterestingnessMap(InterestingnessMap&: InterestingSymbols, Val: sym, TKind);
2288
2289 // FIXME: No tests exist for this code and it is questionable:
2290 // How to handle multiple metadata for the same region?
2291 if (const auto *meta = dyn_cast<SymbolMetadata>(Val: sym))
2292 markInteresting(R: meta->getRegion(), TKind);
2293}
2294
2295void PathSensitiveBugReport::markNotInteresting(SymbolRef sym) {
2296 if (!sym)
2297 return;
2298 InterestingSymbols.erase(Val: sym);
2299
2300 // The metadata part of markInteresting is not reversed here.
2301 // Just making the same region not interesting is incorrect
2302 // in specific cases.
2303 if (const auto *meta = dyn_cast<SymbolMetadata>(Val: sym))
2304 markNotInteresting(R: meta->getRegion());
2305}
2306
2307void PathSensitiveBugReport::markInteresting(const MemRegion *R,
2308 bugreporter::TrackingKind TKind) {
2309 if (!R)
2310 return;
2311
2312 R = R->getBaseRegion();
2313 insertToInterestingnessMap(InterestingnessMap&: InterestingRegions, Val: R, TKind);
2314
2315 if (const auto *SR = dyn_cast<SymbolicRegion>(Val: R))
2316 markInteresting(sym: SR->getSymbol(), TKind);
2317}
2318
2319void PathSensitiveBugReport::markNotInteresting(const MemRegion *R) {
2320 if (!R)
2321 return;
2322
2323 R = R->getBaseRegion();
2324 InterestingRegions.erase(Val: R);
2325
2326 if (const auto *SR = dyn_cast<SymbolicRegion>(Val: R))
2327 markNotInteresting(sym: SR->getSymbol());
2328}
2329
2330void PathSensitiveBugReport::markInteresting(SVal V,
2331 bugreporter::TrackingKind TKind) {
2332 markInteresting(R: V.getAsRegion(), TKind);
2333 markInteresting(sym: V.getAsSymbol(), TKind);
2334}
2335
2336void PathSensitiveBugReport::markInteresting(const LocationContext *LC) {
2337 if (!LC)
2338 return;
2339 InterestingLocationContexts.insert(Ptr: LC);
2340}
2341
2342std::optional<bugreporter::TrackingKind>
2343PathSensitiveBugReport::getInterestingnessKind(SVal V) const {
2344 auto RKind = getInterestingnessKind(R: V.getAsRegion());
2345 auto SKind = getInterestingnessKind(sym: V.getAsSymbol());
2346 if (!RKind)
2347 return SKind;
2348 if (!SKind)
2349 return RKind;
2350
2351 // If either is marked with throrough tracking, return that, we wouldn't like
2352 // to downplay a note's importance by 'only' mentioning it as a condition.
2353 switch(*RKind) {
2354 case bugreporter::TrackingKind::Thorough:
2355 return RKind;
2356 case bugreporter::TrackingKind::Condition:
2357 return SKind;
2358 }
2359
2360 llvm_unreachable(
2361 "BugReport::getInterestingnessKind currently can only handle 2 different "
2362 "tracking kinds! Please define what tracking kind should we return here "
2363 "when the kind of getAsRegion() and getAsSymbol() is different!");
2364 return std::nullopt;
2365}
2366
2367std::optional<bugreporter::TrackingKind>
2368PathSensitiveBugReport::getInterestingnessKind(SymbolRef sym) const {
2369 if (!sym)
2370 return std::nullopt;
2371 // We don't currently consider metadata symbols to be interesting
2372 // even if we know their region is interesting. Is that correct behavior?
2373 auto It = InterestingSymbols.find(Val: sym);
2374 if (It == InterestingSymbols.end())
2375 return std::nullopt;
2376 return It->getSecond();
2377}
2378
2379std::optional<bugreporter::TrackingKind>
2380PathSensitiveBugReport::getInterestingnessKind(const MemRegion *R) const {
2381 if (!R)
2382 return std::nullopt;
2383
2384 R = R->getBaseRegion();
2385 auto It = InterestingRegions.find(Val: R);
2386 if (It != InterestingRegions.end())
2387 return It->getSecond();
2388
2389 if (const auto *SR = dyn_cast<SymbolicRegion>(Val: R))
2390 return getInterestingnessKind(sym: SR->getSymbol());
2391 return std::nullopt;
2392}
2393
2394bool PathSensitiveBugReport::isInteresting(SVal V) const {
2395 return getInterestingnessKind(V).has_value();
2396}
2397
2398bool PathSensitiveBugReport::isInteresting(SymbolRef sym) const {
2399 return getInterestingnessKind(sym).has_value();
2400}
2401
2402bool PathSensitiveBugReport::isInteresting(const MemRegion *R) const {
2403 return getInterestingnessKind(R).has_value();
2404}
2405
2406bool PathSensitiveBugReport::isInteresting(const LocationContext *LC) const {
2407 if (!LC)
2408 return false;
2409 return InterestingLocationContexts.count(Ptr: LC);
2410}
2411
2412const Stmt *PathSensitiveBugReport::getStmt() const {
2413 if (!ErrorNode)
2414 return nullptr;
2415
2416 ProgramPoint ProgP = ErrorNode->getLocation();
2417 const Stmt *S = nullptr;
2418
2419 if (std::optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) {
2420 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
2421 if (BE->getBlock() == &Exit)
2422 S = ErrorNode->getPreviousStmtForDiagnostics();
2423 }
2424 if (!S)
2425 S = ErrorNode->getStmtForDiagnostics();
2426
2427 return S;
2428}
2429
2430ArrayRef<SourceRange>
2431PathSensitiveBugReport::getRanges() const {
2432 // If no custom ranges, add the range of the statement corresponding to
2433 // the error node.
2434 if (Ranges.empty() && isa_and_nonnull<Expr>(Val: getStmt()))
2435 return ErrorNodeRange;
2436
2437 return Ranges;
2438}
2439
2440static bool exitingDestructor(const ExplodedNode *N) {
2441 // Need to loop here, as some times the Error node is already outside of the
2442 // destructor context, and the previous node is an edge that is also outside.
2443 while (N && !N->getLocation().getAs<StmtPoint>()) {
2444 N = N->getFirstPred();
2445 }
2446 return N && isa<CXXDestructorDecl>(Val: N->getLocationContext()->getDecl());
2447}
2448
2449static const Stmt *
2450findReasonableStmtCloseToFunctionExit(const ExplodedNode *N) {
2451 if (exitingDestructor(N)) {
2452 // If we are exiting a destructor call, it is more useful to point to
2453 // the next stmt which is usually the temporary declaration.
2454 if (const Stmt *S = N->getNextStmtForDiagnostics())
2455 return S;
2456 // If next stmt is not found, it is likely the end of a top-level
2457 // function analysis. find the last execution statement then.
2458 }
2459 return N->getPreviousStmtForDiagnostics();
2460}
2461
2462PathDiagnosticLocation
2463PathSensitiveBugReport::getLocation() const {
2464 assert(ErrorNode && "Cannot create a location with a null node.");
2465 const Stmt *S = ErrorNode->getStmtForDiagnostics();
2466 ProgramPoint P = ErrorNode->getLocation();
2467 const LocationContext *LC = P.getLocationContext();
2468 SourceManager &SM =
2469 ErrorNode->getState()->getStateManager().getContext().getSourceManager();
2470
2471 if (!S) {
2472 // If this is an implicit call, return the implicit call point location.
2473 if (std::optional<PreImplicitCall> PIE = P.getAs<PreImplicitCall>())
2474 return PathDiagnosticLocation(PIE->getLocation(), SM);
2475 if (auto FE = P.getAs<FunctionExitPoint>()) {
2476 if (const ReturnStmt *RS = FE->getStmt())
2477 return PathDiagnosticLocation::createBegin(S: RS, SM, LAC: LC);
2478
2479 S = findReasonableStmtCloseToFunctionExit(N: ErrorNode);
2480 }
2481 if (!S)
2482 S = ErrorNode->getNextStmtForDiagnostics();
2483 }
2484
2485 if (S) {
2486 // Attributed statements usually have corrupted begin locations,
2487 // it's OK to ignore attributes for our purposes and deal with
2488 // the actual annotated statement.
2489 if (const auto *AS = dyn_cast<AttributedStmt>(Val: S))
2490 S = AS->getSubStmt();
2491
2492 // For member expressions, return the location of the '.' or '->'.
2493 if (const auto *ME = dyn_cast<MemberExpr>(Val: S))
2494 return PathDiagnosticLocation::createMemberLoc(ME, SM);
2495
2496 // For binary operators, return the location of the operator.
2497 if (const auto *B = dyn_cast<BinaryOperator>(Val: S))
2498 return PathDiagnosticLocation::createOperatorLoc(BO: B, SM);
2499
2500 if (P.getAs<PostStmtPurgeDeadSymbols>())
2501 return PathDiagnosticLocation::createEnd(S, SM, LAC: LC);
2502
2503 if (S->getBeginLoc().isValid())
2504 return PathDiagnosticLocation(S, SM, LC);
2505
2506 return PathDiagnosticLocation(
2507 PathDiagnosticLocation::getValidSourceLocation(S, LAC: LC), SM);
2508 }
2509
2510 return PathDiagnosticLocation::createDeclEnd(LC: ErrorNode->getLocationContext(),
2511 SM);
2512}
2513
2514//===----------------------------------------------------------------------===//
2515// Methods for BugReporter and subclasses.
2516//===----------------------------------------------------------------------===//
2517
2518const ExplodedGraph &PathSensitiveBugReporter::getGraph() const {
2519 return Eng.getGraph();
2520}
2521
2522ProgramStateManager &PathSensitiveBugReporter::getStateManager() const {
2523 return Eng.getStateManager();
2524}
2525
2526BugReporter::BugReporter(BugReporterData &D)
2527 : D(D), UserSuppressions(D.getASTContext()) {}
2528
2529BugReporter::~BugReporter() {
2530 // Make sure reports are flushed.
2531 assert(StrBugTypes.empty() &&
2532 "Destroying BugReporter before diagnostics are emitted!");
2533
2534 // Free the bug reports we are tracking.
2535 for (const auto I : EQClassesVector)
2536 delete I;
2537}
2538
2539void BugReporter::FlushReports() {
2540 // We need to flush reports in deterministic order to ensure the order
2541 // of the reports is consistent between runs.
2542 for (const auto EQ : EQClassesVector)
2543 FlushReport(EQ&: *EQ);
2544
2545 // BugReporter owns and deletes only BugTypes created implicitly through
2546 // EmitBasicReport.
2547 // FIXME: There are leaks from checkers that assume that the BugTypes they
2548 // create will be destroyed by the BugReporter.
2549 StrBugTypes.clear();
2550}
2551
2552//===----------------------------------------------------------------------===//
2553// PathDiagnostics generation.
2554//===----------------------------------------------------------------------===//
2555
2556namespace {
2557
2558/// A wrapper around an ExplodedGraph that contains a single path from the root
2559/// to the error node.
2560class BugPathInfo {
2561public:
2562 std::unique_ptr<ExplodedGraph> BugPath;
2563 PathSensitiveBugReport *Report;
2564 const ExplodedNode *ErrorNode;
2565};
2566
2567/// A wrapper around an ExplodedGraph whose leafs are all error nodes. Can
2568/// conveniently retrieve bug paths from a single error node to the root.
2569class BugPathGetter {
2570 std::unique_ptr<ExplodedGraph> TrimmedGraph;
2571
2572 using PriorityMapTy = llvm::DenseMap<const ExplodedNode *, unsigned>;
2573
2574 /// Assign each node with its distance from the root.
2575 PriorityMapTy PriorityMap;
2576
2577 /// Since the getErrorNode() or BugReport refers to the original ExplodedGraph,
2578 /// we need to pair it to the error node of the constructed trimmed graph.
2579 using ReportNewNodePair =
2580 std::pair<PathSensitiveBugReport *, const ExplodedNode *>;
2581 SmallVector<ReportNewNodePair, 32> ReportNodes;
2582
2583 BugPathInfo CurrentBugPath;
2584
2585 /// A helper class for sorting ExplodedNodes by priority.
2586 template <bool Descending>
2587 class PriorityCompare {
2588 const PriorityMapTy &PriorityMap;
2589
2590 public:
2591 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {}
2592
2593 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const {
2594 PriorityMapTy::const_iterator LI = PriorityMap.find(Val: LHS);
2595 PriorityMapTy::const_iterator RI = PriorityMap.find(Val: RHS);
2596 PriorityMapTy::const_iterator E = PriorityMap.end();
2597
2598 if (LI == E)
2599 return Descending;
2600 if (RI == E)
2601 return !Descending;
2602
2603 return Descending ? LI->second > RI->second
2604 : LI->second < RI->second;
2605 }
2606
2607 bool operator()(const ReportNewNodePair &LHS,
2608 const ReportNewNodePair &RHS) const {
2609 return (*this)(LHS.second, RHS.second);
2610 }
2611 };
2612
2613public:
2614 BugPathGetter(const ExplodedGraph *OriginalGraph,
2615 ArrayRef<PathSensitiveBugReport *> &bugReports);
2616
2617 BugPathInfo *getNextBugPath();
2618};
2619
2620} // namespace
2621
2622BugPathGetter::BugPathGetter(const ExplodedGraph *OriginalGraph,
2623 ArrayRef<PathSensitiveBugReport *> &bugReports) {
2624 SmallVector<const ExplodedNode *, 32> Nodes;
2625 for (const auto I : bugReports) {
2626 assert(I->isValid() &&
2627 "We only allow BugReporterVisitors and BugReporter itself to "
2628 "invalidate reports!");
2629 Nodes.emplace_back(Args: I->getErrorNode());
2630 }
2631
2632 // The trimmed graph is created in the body of the constructor to ensure
2633 // that the DenseMaps have been initialized already.
2634 InterExplodedGraphMap ForwardMap;
2635 TrimmedGraph = OriginalGraph->trim(Nodes, ForwardMap: &ForwardMap);
2636
2637 // Find the (first) error node in the trimmed graph. We just need to consult
2638 // the node map which maps from nodes in the original graph to nodes
2639 // in the new graph.
2640 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes;
2641
2642 for (PathSensitiveBugReport *Report : bugReports) {
2643 const ExplodedNode *NewNode = ForwardMap.lookup(Val: Report->getErrorNode());
2644 assert(NewNode &&
2645 "Failed to construct a trimmed graph that contains this error "
2646 "node!");
2647 ReportNodes.emplace_back(Args&: Report, Args&: NewNode);
2648 RemainingNodes.insert(Ptr: NewNode);
2649 }
2650
2651 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph");
2652
2653 // Perform a forward BFS to find all the shortest paths.
2654 std::queue<const ExplodedNode *> WS;
2655
2656 WS.push(x: TrimmedGraph->getRoot());
2657 unsigned Priority = 0;
2658
2659 while (!WS.empty()) {
2660 const ExplodedNode *Node = WS.front();
2661 WS.pop();
2662
2663 PriorityMapTy::iterator PriorityEntry;
2664 bool IsNew;
2665 std::tie(args&: PriorityEntry, args&: IsNew) = PriorityMap.insert(KV: {Node, Priority});
2666 ++Priority;
2667
2668 if (!IsNew) {
2669 assert(PriorityEntry->second <= Priority);
2670 continue;
2671 }
2672
2673 if (RemainingNodes.erase(Ptr: Node))
2674 if (RemainingNodes.empty())
2675 break;
2676
2677 for (const ExplodedNode *Succ : Node->succs())
2678 WS.push(x: Succ);
2679 }
2680
2681 // Sort the error paths from longest to shortest.
2682 llvm::sort(C&: ReportNodes, Comp: PriorityCompare<true>(PriorityMap));
2683}
2684
2685BugPathInfo *BugPathGetter::getNextBugPath() {
2686 if (ReportNodes.empty())
2687 return nullptr;
2688
2689 const ExplodedNode *OrigN;
2690 std::tie(args&: CurrentBugPath.Report, args&: OrigN) = ReportNodes.pop_back_val();
2691 assert(PriorityMap.contains(OrigN) && "error node not accessible from root");
2692
2693 // Create a new graph with a single path. This is the graph that will be
2694 // returned to the caller.
2695 auto GNew = std::make_unique<ExplodedGraph>();
2696
2697 // Now walk from the error node up the BFS path, always taking the
2698 // predeccessor with the lowest number.
2699 ExplodedNode *Succ = nullptr;
2700 while (true) {
2701 // Create the equivalent node in the new graph with the same state
2702 // and location.
2703 ExplodedNode *NewN = GNew->createUncachedNode(
2704 L: OrigN->getLocation(), State: OrigN->getState(),
2705 Id: OrigN->getID(), IsSink: OrigN->isSink());
2706
2707 // Link up the new node with the previous node.
2708 if (Succ)
2709 Succ->addPredecessor(V: NewN, G&: *GNew);
2710 else
2711 CurrentBugPath.ErrorNode = NewN;
2712
2713 Succ = NewN;
2714
2715 // Are we at the final node?
2716 if (OrigN->pred_empty()) {
2717 assert(OrigN == TrimmedGraph->getRoot() &&
2718 "There should be only one root!");
2719 GNew->designateAsRoot(V: NewN);
2720 break;
2721 }
2722
2723 // Find the next predeccessor node. We choose the node that is marked
2724 // with the lowest BFS number.
2725 OrigN = *std::min_element(first: OrigN->pred_begin(), last: OrigN->pred_end(),
2726 comp: PriorityCompare<false>(PriorityMap));
2727 }
2728
2729 CurrentBugPath.BugPath = std::move(GNew);
2730
2731 return &CurrentBugPath;
2732}
2733
2734/// CompactMacroExpandedPieces - This function postprocesses a PathDiagnostic
2735/// object and collapses PathDiagosticPieces that are expanded by macros.
2736static void CompactMacroExpandedPieces(PathPieces &path,
2737 const SourceManager& SM) {
2738 using MacroStackTy = std::vector<
2739 std::pair<std::shared_ptr<PathDiagnosticMacroPiece>, SourceLocation>>;
2740
2741 using PiecesTy = std::vector<PathDiagnosticPieceRef>;
2742
2743 MacroStackTy MacroStack;
2744 PiecesTy Pieces;
2745
2746 for (PathPieces::const_iterator I = path.begin(), E = path.end();
2747 I != E; ++I) {
2748 const auto &piece = *I;
2749
2750 // Recursively compact calls.
2751 if (auto *call = dyn_cast<PathDiagnosticCallPiece>(Val: &*piece)) {
2752 CompactMacroExpandedPieces(path&: call->path, SM);
2753 }
2754
2755 // Get the location of the PathDiagnosticPiece.
2756 const FullSourceLoc Loc = piece->getLocation().asLocation();
2757
2758 // Determine the instantiation location, which is the location we group
2759 // related PathDiagnosticPieces.
2760 SourceLocation InstantiationLoc = Loc.isMacroID() ?
2761 SM.getExpansionLoc(Loc) :
2762 SourceLocation();
2763
2764 if (Loc.isFileID()) {
2765 MacroStack.clear();
2766 Pieces.push_back(x: piece);
2767 continue;
2768 }
2769
2770 assert(Loc.isMacroID());
2771
2772 // Is the PathDiagnosticPiece within the same macro group?
2773 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
2774 MacroStack.back().first->subPieces.push_back(x: piece);
2775 continue;
2776 }
2777
2778 // We aren't in the same group. Are we descending into a new macro
2779 // or are part of an old one?
2780 std::shared_ptr<PathDiagnosticMacroPiece> MacroGroup;
2781
2782 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
2783 SM.getExpansionLoc(Loc) :
2784 SourceLocation();
2785
2786 // Walk the entire macro stack.
2787 while (!MacroStack.empty()) {
2788 if (InstantiationLoc == MacroStack.back().second) {
2789 MacroGroup = MacroStack.back().first;
2790 break;
2791 }
2792
2793 if (ParentInstantiationLoc == MacroStack.back().second) {
2794 MacroGroup = MacroStack.back().first;
2795 break;
2796 }
2797
2798 MacroStack.pop_back();
2799 }
2800
2801 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) {
2802 // Create a new macro group and add it to the stack.
2803 auto NewGroup = std::make_shared<PathDiagnosticMacroPiece>(
2804 args: PathDiagnosticLocation::createSingleLocation(PDL: piece->getLocation()));
2805
2806 if (MacroGroup)
2807 MacroGroup->subPieces.push_back(x: NewGroup);
2808 else {
2809 assert(InstantiationLoc.isFileID());
2810 Pieces.push_back(x: NewGroup);
2811 }
2812
2813 MacroGroup = NewGroup;
2814 MacroStack.push_back(x: std::make_pair(x&: MacroGroup, y&: InstantiationLoc));
2815 }
2816
2817 // Finally, add the PathDiagnosticPiece to the group.
2818 MacroGroup->subPieces.push_back(x: piece);
2819 }
2820
2821 // Now take the pieces and construct a new PathDiagnostic.
2822 path.clear();
2823
2824 llvm::append_range(C&: path, R&: Pieces);
2825}
2826
2827/// Generate notes from all visitors.
2828/// Notes associated with @c ErrorNode are generated using
2829/// @c getEndPath, and the rest are generated with @c VisitNode.
2830static std::unique_ptr<VisitorsDiagnosticsTy>
2831generateVisitorsDiagnostics(PathSensitiveBugReport *R,
2832 const ExplodedNode *ErrorNode,
2833 BugReporterContext &BRC) {
2834 std::unique_ptr<VisitorsDiagnosticsTy> Notes =
2835 std::make_unique<VisitorsDiagnosticsTy>();
2836 PathSensitiveBugReport::VisitorList visitors;
2837
2838 // Run visitors on all nodes starting from the node *before* the last one.
2839 // The last node is reserved for notes generated with @c getEndPath.
2840 const ExplodedNode *NextNode = ErrorNode->getFirstPred();
2841 while (NextNode) {
2842
2843 // At each iteration, move all visitors from report to visitor list. This is
2844 // important, because the Profile() functions of the visitors make sure that
2845 // a visitor isn't added multiple times for the same node, but it's fine
2846 // to add the a visitor with Profile() for different nodes (e.g. tracking
2847 // a region at different points of the symbolic execution).
2848 for (std::unique_ptr<BugReporterVisitor> &Visitor : R->visitors())
2849 visitors.push_back(Elt: std::move(Visitor));
2850
2851 R->clearVisitors();
2852
2853 const ExplodedNode *Pred = NextNode->getFirstPred();
2854 if (!Pred) {
2855 PathDiagnosticPieceRef LastPiece;
2856 for (auto &V : visitors) {
2857 V->finalizeVisitor(BRC, EndPathNode: ErrorNode, BR&: *R);
2858
2859 if (auto Piece = V->getEndPath(BRC, N: ErrorNode, BR&: *R)) {
2860 assert(!LastPiece &&
2861 "There can only be one final piece in a diagnostic.");
2862 assert(Piece->getKind() == PathDiagnosticPiece::Kind::Event &&
2863 "The final piece must contain a message!");
2864 LastPiece = std::move(Piece);
2865 (*Notes)[ErrorNode].push_back(x: LastPiece);
2866 }
2867 }
2868 break;
2869 }
2870
2871 for (auto &V : visitors) {
2872 auto P = V->VisitNode(Succ: NextNode, BRC, BR&: *R);
2873 if (P)
2874 (*Notes)[NextNode].push_back(x: std::move(P));
2875 }
2876
2877 if (!R->isValid())
2878 break;
2879
2880 NextNode = Pred;
2881 }
2882
2883 return Notes;
2884}
2885
2886std::optional<PathDiagnosticBuilder> PathDiagnosticBuilder::findValidReport(
2887 ArrayRef<PathSensitiveBugReport *> &bugReports,
2888 PathSensitiveBugReporter &Reporter) {
2889 Z3CrosscheckOracle Z3Oracle(Reporter.getAnalyzerOptions());
2890
2891 BugPathGetter BugGraph(&Reporter.getGraph(), bugReports);
2892
2893 while (BugPathInfo *BugPath = BugGraph.getNextBugPath()) {
2894 // Find the BugReport with the original location.
2895 PathSensitiveBugReport *R = BugPath->Report;
2896 assert(R && "No original report found for sliced graph.");
2897 assert(R->isValid() && "Report selected by trimmed graph marked invalid.");
2898 const ExplodedNode *ErrorNode = BugPath->ErrorNode;
2899
2900 // Register refutation visitors first, if they mark the bug invalid no
2901 // further analysis is required
2902 R->addVisitor<LikelyFalsePositiveSuppressionBRVisitor>();
2903
2904 // Register additional node visitors.
2905 R->addVisitor<NilReceiverBRVisitor>();
2906 R->addVisitor<ConditionBRVisitor>();
2907 R->addVisitor<TagVisitor>();
2908
2909 BugReporterContext BRC(Reporter);
2910
2911 // Run all visitors on a given graph, once.
2912 std::unique_ptr<VisitorsDiagnosticsTy> visitorNotes =
2913 generateVisitorsDiagnostics(R, ErrorNode, BRC);
2914
2915 if (R->isValid()) {
2916 if (Reporter.getAnalyzerOptions().ShouldCrosscheckWithZ3) {
2917 llvm::TimeTraceScope TCS{"Crosscheck with Z3"};
2918 // If crosscheck is enabled, remove all visitors, add the refutation
2919 // visitor and check again
2920 R->clearVisitors();
2921 Z3CrosscheckVisitor::Z3Result CrosscheckResult;
2922 R->addVisitor<Z3CrosscheckVisitor>(ConstructorArgs&: CrosscheckResult,
2923 ConstructorArgs: Reporter.getAnalyzerOptions());
2924
2925 // We don't overwrite the notes inserted by other visitors because the
2926 // refutation manager does not add any new note to the path
2927 generateVisitorsDiagnostics(R, ErrorNode: BugPath->ErrorNode, BRC);
2928 switch (Z3Oracle.interpretQueryResult(Meta: CrosscheckResult)) {
2929 case Z3CrosscheckOracle::RejectReport:
2930 ++NumTimesReportRefuted;
2931 R->markInvalid(Tag: "Infeasible constraints", /*Data=*/nullptr);
2932 continue;
2933 case Z3CrosscheckOracle::RejectEQClass:
2934 ++NumTimesReportEQClassAborted;
2935 return {};
2936 case Z3CrosscheckOracle::AcceptReport:
2937 ++NumTimesReportPassesZ3;
2938 break;
2939 }
2940 }
2941
2942 assert(R->isValid());
2943 return PathDiagnosticBuilder(std::move(BRC), std::move(BugPath->BugPath),
2944 BugPath->Report, BugPath->ErrorNode,
2945 std::move(visitorNotes));
2946 }
2947 }
2948
2949 ++NumTimesReportEQClassWasExhausted;
2950 return {};
2951}
2952
2953std::unique_ptr<DiagnosticForConsumerMapTy>
2954PathSensitiveBugReporter::generatePathDiagnostics(
2955 ArrayRef<std::unique_ptr<PathDiagnosticConsumer>> consumers,
2956 ArrayRef<PathSensitiveBugReport *> &bugReports) {
2957 assert(!bugReports.empty());
2958
2959 auto Out = std::make_unique<DiagnosticForConsumerMapTy>();
2960
2961 std::optional<PathDiagnosticBuilder> PDB =
2962 PathDiagnosticBuilder::findValidReport(bugReports, Reporter&: *this);
2963
2964 if (PDB) {
2965 for (const auto &PC : consumers) {
2966 if (std::unique_ptr<PathDiagnostic> PD = PDB->generate(PDC: PC.get())) {
2967 (*Out)[PC.get()] = std::move(PD);
2968 }
2969 }
2970 }
2971
2972 return Out;
2973}
2974
2975void BugReporter::emitReport(std::unique_ptr<BugReport> R) {
2976 bool ValidSourceLoc = R->getLocation().isValid();
2977 assert(ValidSourceLoc);
2978 // If we mess up in a release build, we'd still prefer to just drop the bug
2979 // instead of trying to go on.
2980 if (!ValidSourceLoc)
2981 return;
2982
2983 // If the user asked to suppress this report, we should skip it.
2984 if (UserSuppressions.isSuppressed(*R))
2985 return;
2986
2987 // Compute the bug report's hash to determine its equivalence class.
2988 llvm::FoldingSetNodeID ID;
2989 R->Profile(hash&: ID);
2990
2991 // Lookup the equivance class. If there isn't one, create it.
2992 void *InsertPos;
2993 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
2994
2995 if (!EQ) {
2996 EQ = new BugReportEquivClass(std::move(R));
2997 EQClasses.InsertNode(N: EQ, InsertPos);
2998 EQClassesVector.push_back(x: EQ);
2999 } else
3000 EQ->AddReport(R: std::move(R));
3001}
3002
3003void PathSensitiveBugReporter::emitReport(std::unique_ptr<BugReport> R) {
3004 if (auto PR = dyn_cast<PathSensitiveBugReport>(Val: R.get()))
3005 if (const ExplodedNode *E = PR->getErrorNode()) {
3006 // An error node must either be a sink or have a tag, otherwise
3007 // it could get reclaimed before the path diagnostic is created.
3008 assert((E->isSink() || E->getLocation().getTag()) &&
3009 "Error node must either be a sink or have a tag");
3010
3011 const AnalysisDeclContext *DeclCtx =
3012 E->getLocationContext()->getAnalysisDeclContext();
3013 // The source of autosynthesized body can be handcrafted AST or a model
3014 // file. The locations from handcrafted ASTs have no valid source
3015 // locations and have to be discarded. Locations from model files should
3016 // be preserved for processing and reporting.
3017 if (DeclCtx->isBodyAutosynthesized() &&
3018 !DeclCtx->isBodyAutosynthesizedFromModelFile())
3019 return;
3020 }
3021
3022 BugReporter::emitReport(R: std::move(R));
3023}
3024
3025//===----------------------------------------------------------------------===//
3026// Emitting reports in equivalence classes.
3027//===----------------------------------------------------------------------===//
3028
3029namespace {
3030
3031struct FRIEC_WLItem {
3032 const ExplodedNode *N;
3033 ExplodedNode::const_succ_iterator I, E;
3034
3035 FRIEC_WLItem(const ExplodedNode *n)
3036 : N(n), I(N->succ_begin()), E(N->succ_end()) {}
3037};
3038
3039} // namespace
3040
3041BugReport *PathSensitiveBugReporter::findReportInEquivalenceClass(
3042 BugReportEquivClass &EQ, SmallVectorImpl<BugReport *> &bugReports) {
3043 // If we don't need to suppress any of the nodes because they are
3044 // post-dominated by a sink, simply add all the nodes in the equivalence class
3045 // to 'Nodes'. Any of the reports will serve as a "representative" report.
3046 assert(EQ.getReports().size() > 0);
3047 const BugType& BT = EQ.getReports()[0]->getBugType();
3048 if (!BT.isSuppressOnSink()) {
3049 BugReport *R = EQ.getReports()[0].get();
3050 for (auto &J : EQ.getReports()) {
3051 if (auto *PR = dyn_cast<PathSensitiveBugReport>(Val: J.get())) {
3052 R = PR;
3053 bugReports.push_back(Elt: PR);
3054 }
3055 }
3056 return R;
3057 }
3058
3059 // For bug reports that should be suppressed when all paths are post-dominated
3060 // by a sink node, iterate through the reports in the equivalence class
3061 // until we find one that isn't post-dominated (if one exists). We use a
3062 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write
3063 // this as a recursive function, but we don't want to risk blowing out the
3064 // stack for very long paths.
3065 BugReport *exampleReport = nullptr;
3066
3067 for (const auto &I: EQ.getReports()) {
3068 auto *R = dyn_cast<PathSensitiveBugReport>(Val: I.get());
3069 if (!R)
3070 continue;
3071
3072 const ExplodedNode *errorNode = R->getErrorNode();
3073 if (errorNode->isSink()) {
3074 llvm_unreachable(
3075 "BugType::isSuppressSink() should not be 'true' for sink end nodes");
3076 }
3077 // No successors? By definition this nodes isn't post-dominated by a sink.
3078 if (errorNode->succ_empty()) {
3079 bugReports.push_back(Elt: R);
3080 if (!exampleReport)
3081 exampleReport = R;
3082 continue;
3083 }
3084
3085 // See if we are in a no-return CFG block. If so, treat this similarly
3086 // to being post-dominated by a sink. This works better when the analysis
3087 // is incomplete and we have never reached the no-return function call(s)
3088 // that we'd inevitably bump into on this path.
3089 if (const CFGBlock *ErrorB = errorNode->getCFGBlock())
3090 if (ErrorB->isInevitablySinking())
3091 continue;
3092
3093 // At this point we know that 'N' is not a sink and it has at least one
3094 // successor. Use a DFS worklist to find a non-sink end-of-path node.
3095 using WLItem = FRIEC_WLItem;
3096 using DFSWorkList = SmallVector<WLItem, 10>;
3097
3098 llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
3099
3100 DFSWorkList WL;
3101 WL.push_back(Elt: errorNode);
3102 Visited[errorNode] = 1;
3103
3104 while (!WL.empty()) {
3105 WLItem &WI = WL.back();
3106 assert(!WI.N->succ_empty());
3107
3108 for (; WI.I != WI.E; ++WI.I) {
3109 const ExplodedNode *Succ = *WI.I;
3110 // End-of-path node?
3111 if (Succ->succ_empty()) {
3112 // If we found an end-of-path node that is not a sink.
3113 if (!Succ->isSink()) {
3114 bugReports.push_back(Elt: R);
3115 if (!exampleReport)
3116 exampleReport = R;
3117 WL.clear();
3118 break;
3119 }
3120 // Found a sink? Continue on to the next successor.
3121 continue;
3122 }
3123 // Mark the successor as visited. If it hasn't been explored,
3124 // enqueue it to the DFS worklist.
3125 unsigned &mark = Visited[Succ];
3126 if (!mark) {
3127 mark = 1;
3128 WL.push_back(Elt: Succ);
3129 break;
3130 }
3131 }
3132
3133 // The worklist may have been cleared at this point. First
3134 // check if it is empty before checking the last item.
3135 if (!WL.empty() && &WL.back() == &WI)
3136 WL.pop_back();
3137 }
3138 }
3139
3140 // ExampleReport will be NULL if all the nodes in the equivalence class
3141 // were post-dominated by sinks.
3142 return exampleReport;
3143}
3144
3145void BugReporter::FlushReport(BugReportEquivClass &EQ) {
3146 llvm::TimeTraceScope TCS{timeTraceName(EQ), [&]() {
3147 return timeTraceMetadata(EQ, SM: getSourceManager());
3148 }};
3149 SmallVector<BugReport*, 10> bugReports;
3150 BugReport *report = findReportInEquivalenceClass(eqClass&: EQ, bugReports);
3151 if (!report)
3152 return;
3153
3154 // See whether we need to silence the checker/package.
3155 for (const std::string &CheckerOrPackage :
3156 getAnalyzerOptions().SilencedCheckersAndPackages) {
3157 if (report->getBugType().getCheckerName().starts_with(Prefix: CheckerOrPackage))
3158 return;
3159 }
3160
3161 ArrayRef Consumers = getPathDiagnosticConsumers();
3162 std::unique_ptr<DiagnosticForConsumerMapTy> Diagnostics =
3163 generateDiagnosticForConsumerMap(exampleReport: report, consumers: Consumers, bugReports);
3164
3165 for (auto &P : *Diagnostics) {
3166 PathDiagnosticConsumer *Consumer = P.first;
3167 std::unique_ptr<PathDiagnostic> &PD = P.second;
3168
3169 // If the path is empty, generate a single step path with the location
3170 // of the issue.
3171 if (PD->path.empty()) {
3172 PathDiagnosticLocation L = report->getLocation();
3173 auto piece = std::make_unique<PathDiagnosticEventPiece>(
3174 args&: L, args: report->getDescription());
3175 for (SourceRange Range : report->getRanges())
3176 piece->addRange(R: Range);
3177 PD->setEndOfPath(std::move(piece));
3178 }
3179
3180 PathPieces &Pieces = PD->getMutablePieces();
3181 if (getAnalyzerOptions().ShouldDisplayNotesAsEvents) {
3182 // For path diagnostic consumers that don't support extra notes,
3183 // we may optionally convert those to path notes.
3184 for (const auto &I : llvm::reverse(C: report->getNotes())) {
3185 PathDiagnosticNotePiece *Piece = I.get();
3186 auto ConvertedPiece = std::make_shared<PathDiagnosticEventPiece>(
3187 args: Piece->getLocation(), args: Piece->getString());
3188 for (const auto &R: Piece->getRanges())
3189 ConvertedPiece->addRange(R);
3190
3191 Pieces.push_front(x: std::move(ConvertedPiece));
3192 }
3193 } else {
3194 for (const auto &I : llvm::reverse(C: report->getNotes()))
3195 Pieces.push_front(x: I);
3196 }
3197
3198 for (const auto &I : report->getFixits())
3199 Pieces.back()->addFixit(F: I);
3200
3201 updateExecutedLinesWithDiagnosticPieces(PD&: *PD);
3202
3203 // If we are debugging, let's have the entry point as the first note.
3204 if (getAnalyzerOptions().AnalyzerDisplayProgress ||
3205 getAnalyzerOptions().AnalyzerNoteAnalysisEntryPoints) {
3206 const Decl *EntryPoint = getAnalysisEntryPoint();
3207 Pieces.push_front(x: std::make_shared<PathDiagnosticEventPiece>(
3208 args: PathDiagnosticLocation{EntryPoint->getLocation(), getSourceManager()},
3209 args: "[debug] analyzing from " +
3210 AnalysisDeclContext::getFunctionName(D: EntryPoint)));
3211 }
3212 Consumer->HandlePathDiagnostic(D: std::move(PD));
3213 }
3214}
3215
3216/// Insert all lines participating in the function signature \p Signature
3217/// into \p ExecutedLines.
3218static void populateExecutedLinesWithFunctionSignature(
3219 const Decl *Signature, const SourceManager &SM,
3220 FilesToLineNumsMap &ExecutedLines) {
3221 SourceRange SignatureSourceRange;
3222 const Stmt* Body = Signature->getBody();
3223 if (const auto FD = dyn_cast<FunctionDecl>(Val: Signature)) {
3224 SignatureSourceRange = FD->getSourceRange();
3225 } else if (const auto OD = dyn_cast<ObjCMethodDecl>(Val: Signature)) {
3226 SignatureSourceRange = OD->getSourceRange();
3227 } else {
3228 return;
3229 }
3230 SourceLocation Start = SignatureSourceRange.getBegin();
3231 SourceLocation End = Body ? Body->getSourceRange().getBegin()
3232 : SignatureSourceRange.getEnd();
3233 if (!Start.isValid() || !End.isValid())
3234 return;
3235 unsigned StartLine = SM.getExpansionLineNumber(Loc: Start);
3236 unsigned EndLine = SM.getExpansionLineNumber(Loc: End);
3237
3238 FileID FID = SM.getFileID(SpellingLoc: SM.getExpansionLoc(Loc: Start));
3239 for (unsigned Line = StartLine; Line <= EndLine; Line++)
3240 ExecutedLines[FID].insert(x: Line);
3241}
3242
3243static void populateExecutedLinesWithStmt(
3244 const Stmt *S, const SourceManager &SM,
3245 FilesToLineNumsMap &ExecutedLines) {
3246 SourceLocation Loc = S->getSourceRange().getBegin();
3247 if (!Loc.isValid())
3248 return;
3249 SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc);
3250 FileID FID = SM.getFileID(SpellingLoc: ExpansionLoc);
3251 unsigned LineNo = SM.getExpansionLineNumber(Loc: ExpansionLoc);
3252 ExecutedLines[FID].insert(x: LineNo);
3253}
3254
3255/// \return all executed lines including function signatures on the path
3256/// starting from \p N.
3257static std::unique_ptr<FilesToLineNumsMap>
3258findExecutedLines(const SourceManager &SM, const ExplodedNode *N) {
3259 auto ExecutedLines = std::make_unique<FilesToLineNumsMap>();
3260
3261 while (N) {
3262 if (N->getFirstPred() == nullptr) {
3263 // First node: show signature of the entrance point.
3264 const Decl *D = N->getLocationContext()->getDecl();
3265 populateExecutedLinesWithFunctionSignature(Signature: D, SM, ExecutedLines&: *ExecutedLines);
3266 } else if (auto CE = N->getLocationAs<CallEnter>()) {
3267 // Inlined function: show signature.
3268 const Decl* D = CE->getCalleeContext()->getDecl();
3269 populateExecutedLinesWithFunctionSignature(Signature: D, SM, ExecutedLines&: *ExecutedLines);
3270 } else if (const Stmt *S = N->getStmtForDiagnostics()) {
3271 populateExecutedLinesWithStmt(S, SM, ExecutedLines&: *ExecutedLines);
3272
3273 // Show extra context for some parent kinds.
3274 const Stmt *P = N->getParentMap().getParent(S);
3275
3276 // The path exploration can die before the node with the associated
3277 // return statement is generated, but we do want to show the whole
3278 // return.
3279 if (const auto *RS = dyn_cast_or_null<ReturnStmt>(Val: P)) {
3280 populateExecutedLinesWithStmt(S: RS, SM, ExecutedLines&: *ExecutedLines);
3281 P = N->getParentMap().getParent(S: RS);
3282 }
3283
3284 if (isa_and_nonnull<SwitchCase, LabelStmt>(Val: P))
3285 populateExecutedLinesWithStmt(S: P, SM, ExecutedLines&: *ExecutedLines);
3286 }
3287
3288 N = N->getFirstPred();
3289 }
3290 return ExecutedLines;
3291}
3292
3293std::unique_ptr<DiagnosticForConsumerMapTy>
3294BugReporter::generateDiagnosticForConsumerMap(
3295 BugReport *exampleReport,
3296 ArrayRef<std::unique_ptr<PathDiagnosticConsumer>> consumers,
3297 ArrayRef<BugReport *> bugReports) {
3298 auto *basicReport = cast<BasicBugReport>(Val: exampleReport);
3299 auto Out = std::make_unique<DiagnosticForConsumerMapTy>();
3300 for (const auto &Consumer : consumers)
3301 (*Out)[Consumer.get()] =
3302 generateDiagnosticForBasicReport(R: basicReport, AnalysisEntryPoint);
3303 return Out;
3304}
3305
3306static PathDiagnosticCallPiece *
3307getFirstStackedCallToHeaderFile(PathDiagnosticCallPiece *CP,
3308 const SourceManager &SMgr) {
3309 SourceLocation CallLoc = CP->callEnter.asLocation();
3310
3311 // If the call is within a macro, don't do anything (for now).
3312 if (CallLoc.isMacroID())
3313 return nullptr;
3314
3315 assert(AnalysisManager::isInCodeFile(CallLoc, SMgr) &&
3316 "The call piece should not be in a header file.");
3317
3318 // Check if CP represents a path through a function outside of the main file.
3319 if (!AnalysisManager::isInCodeFile(SL: CP->callEnterWithin.asLocation(), SM: SMgr))
3320 return CP;
3321
3322 const PathPieces &Path = CP->path;
3323 if (Path.empty())
3324 return nullptr;
3325
3326 // Check if the last piece in the callee path is a call to a function outside
3327 // of the main file.
3328 if (auto *CPInner = dyn_cast<PathDiagnosticCallPiece>(Val: Path.back().get()))
3329 return getFirstStackedCallToHeaderFile(CP: CPInner, SMgr);
3330
3331 // Otherwise, the last piece is in the main file.
3332 return nullptr;
3333}
3334
3335static void resetDiagnosticLocationToMainFile(PathDiagnostic &PD) {
3336 if (PD.path.empty())
3337 return;
3338
3339 PathDiagnosticPiece *LastP = PD.path.back().get();
3340 assert(LastP);
3341 const SourceManager &SMgr = LastP->getLocation().getManager();
3342
3343 // We only need to check if the report ends inside headers, if the last piece
3344 // is a call piece.
3345 if (auto *CP = dyn_cast<PathDiagnosticCallPiece>(Val: LastP)) {
3346 CP = getFirstStackedCallToHeaderFile(CP, SMgr);
3347 if (CP) {
3348 // Mark the piece.
3349 CP->setAsLastInMainSourceFile();
3350
3351 // Update the path diagnostic message.
3352 const auto *ND = dyn_cast<NamedDecl>(Val: CP->getCallee());
3353 if (ND) {
3354 SmallString<200> buf;
3355 llvm::raw_svector_ostream os(buf);
3356 os << " (within a call to '" << ND->getDeclName() << "')";
3357 PD.appendToDesc(S: os.str());
3358 }
3359
3360 // Reset the report containing declaration and location.
3361 PD.setDeclWithIssue(CP->getCaller());
3362 PD.setLocation(CP->getLocation());
3363
3364 return;
3365 }
3366 }
3367}
3368
3369std::unique_ptr<DiagnosticForConsumerMapTy>
3370PathSensitiveBugReporter::generateDiagnosticForConsumerMap(
3371 BugReport *exampleReport,
3372 ArrayRef<std::unique_ptr<PathDiagnosticConsumer>> consumers,
3373 ArrayRef<BugReport *> bugReports) {
3374 if (isa<BasicBugReport>(Val: exampleReport))
3375 return BugReporter::generateDiagnosticForConsumerMap(exampleReport,
3376 consumers, bugReports);
3377
3378 // Generate the full path sensitive diagnostic, using the generation scheme
3379 // specified by the PathDiagnosticConsumer. Note that we have to generate
3380 // path diagnostics even for consumers which do not support paths, because
3381 // the BugReporterVisitors may mark this bug as a false positive.
3382 assert(!bugReports.empty());
3383 MaxBugClassSize.updateMax(Value: bugReports.size());
3384
3385 // Avoid copying the whole array because there may be a lot of reports.
3386 ArrayRef<PathSensitiveBugReport *> convertedArrayOfReports(
3387 reinterpret_cast<PathSensitiveBugReport *const *>(&*bugReports.begin()),
3388 reinterpret_cast<PathSensitiveBugReport *const *>(&*bugReports.end()));
3389 std::unique_ptr<DiagnosticForConsumerMapTy> Out = generatePathDiagnostics(
3390 consumers, bugReports&: convertedArrayOfReports);
3391
3392 if (Out->empty())
3393 return Out;
3394
3395 MaxValidBugClassSize.updateMax(Value: bugReports.size());
3396
3397 // Examine the report and see if the last piece is in a header. Reset the
3398 // report location to the last piece in the main source file.
3399 const AnalyzerOptions &Opts = getAnalyzerOptions();
3400 for (auto const &P : *Out)
3401 if (Opts.ShouldReportIssuesInMainSourceFile && !Opts.AnalyzeAll)
3402 resetDiagnosticLocationToMainFile(PD&: *P.second);
3403
3404 return Out;
3405}
3406
3407void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3408 const CheckerFrontend *Checker,
3409 StringRef Name, StringRef Category,
3410 StringRef Str, PathDiagnosticLocation Loc,
3411 ArrayRef<SourceRange> Ranges,
3412 ArrayRef<FixItHint> Fixits) {
3413 EmitBasicReport(DeclWithIssue, CheckerName: Checker->getName(), BugName: Name, BugCategory: Category, BugStr: Str, Loc,
3414 Ranges, Fixits);
3415}
3416
3417void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3418 CheckerNameRef CheckName,
3419 StringRef name, StringRef category,
3420 StringRef str, PathDiagnosticLocation Loc,
3421 ArrayRef<SourceRange> Ranges,
3422 ArrayRef<FixItHint> Fixits) {
3423 // 'BT' is owned by BugReporter.
3424 BugType *BT = getBugTypeForName(CheckerName: CheckName, name, category);
3425 auto R = std::make_unique<BasicBugReport>(args&: *BT, args&: str, args&: Loc);
3426 R->setDeclWithIssue(DeclWithIssue);
3427 for (const auto &SR : Ranges)
3428 R->addRange(R: SR);
3429 for (const auto &FH : Fixits)
3430 R->addFixItHint(F: FH);
3431 emitReport(R: std::move(R));
3432}
3433
3434BugType *BugReporter::getBugTypeForName(CheckerNameRef CheckName,
3435 StringRef name, StringRef category) {
3436 SmallString<136> fullDesc;
3437 llvm::raw_svector_ostream(fullDesc)
3438 << CheckName << ":" << name << ":" << category;
3439 std::unique_ptr<BugType> &BT = StrBugTypes[fullDesc];
3440 if (!BT)
3441 BT = std::make_unique<BugType>(args&: CheckName, args&: name, args&: category);
3442 return BT.get();
3443}
3444