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