1//===- BugReporter.cpp - Generate PathDiagnostics for bugs ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines BugReporter, a utility class for generating
10// PathDiagnostics.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
15#include "clang/AST/ASTTypeTraits.h"
16#include "clang/AST/Attr.h"
17#include "clang/AST/Decl.h"
18#include "clang/AST/DeclBase.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/Expr.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/ParentMap.h"
23#include "clang/AST/Stmt.h"
24#include "clang/AST/StmtCXX.h"
25#include "clang/AST/StmtObjC.h"
26#include "clang/Analysis/AnalysisDeclContext.h"
27#include "clang/Analysis/CFG.h"
28#include "clang/Analysis/CFGStmtMap.h"
29#include "clang/Analysis/PathDiagnostic.h"
30#include "clang/Analysis/ProgramPoint.h"
31#include "clang/Basic/LLVM.h"
32#include "clang/Basic/SourceLocation.h"
33#include "clang/Basic/SourceManager.h"
34#include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
35#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
36#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
37#include "clang/StaticAnalyzer/Core/BugReporter/Z3CrosscheckVisitor.h"
38#include "clang/StaticAnalyzer/Core/Checker.h"
39#include "clang/StaticAnalyzer/Core/CheckerManager.h"
40#include "clang/StaticAnalyzer/Core/CheckerRegistryData.h"
41#include "clang/StaticAnalyzer/Core/PathSensitive/EntryPointStats.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/SVals.h"
47#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
48#include "llvm/ADT/ArrayRef.h"
49#include "llvm/ADT/DenseMap.h"
50#include "llvm/ADT/DenseSet.h"
51#include "llvm/ADT/FoldingSet.h"
52#include "llvm/ADT/STLExtras.h"
53#include "llvm/ADT/SmallPtrSet.h"
54#include "llvm/ADT/StringExtras.h"
55#include "llvm/ADT/StringRef.h"
56#include "llvm/Support/Compiler.h"
57#include "llvm/Support/ErrorHandling.h"
58#include "llvm/Support/TimeProfiler.h"
59#include "llvm/Support/raw_ostream.h"
60#include <algorithm>
61#include <cassert>
62#include <cstddef>
63#include <iterator>
64#include <memory>
65#include <optional>
66#include <queue>
67#include <string>
68#include <tuple>
69#include <utility>
70#include <vector>
71
72using namespace clang;
73using namespace ento;
74using namespace llvm;
75
76#define DEBUG_TYPE "BugReporter"
77
78STAT_MAX(MaxBugClassSize,
79 "The maximum number of bug reports in the same equivalence class");
80STAT_MAX(MaxValidBugClassSize,
81 "The maximum number of bug reports in the same equivalence class "
82 "where at least one report is valid (not suppressed)");
83
84STAT_COUNTER(NumTimesReportPassesZ3, "Number of reports passed Z3");
85STAT_COUNTER(NumTimesReportRefuted, "Number of reports refuted by Z3");
86STAT_COUNTER(NumTimesReportEQClassAborted,
87 "Number of times a report equivalence class was aborted by the Z3 "
88 "oracle heuristic");
89STAT_COUNTER(NumTimesReportEQClassWasExhausted,
90 "Number of times all reports of an equivalence class was refuted");
91
92BugReporterVisitor::~BugReporterVisitor() = default;
93
94void BugReporterContext::anchor() {}
95
96//===----------------------------------------------------------------------===//
97// PathDiagnosticBuilder and its associated routines and helper objects.
98//===----------------------------------------------------------------------===//
99
100namespace {
101
102/// A (CallPiece, node assiciated with its CallEnter) pair.
103using CallWithEntry =
104 std::pair<PathDiagnosticCallPiece *, const ExplodedNode *>;
105using CallWithEntryStack = SmallVector<CallWithEntry, 6>;
106
107/// Map from each node to the diagnostic pieces visitors emit for them.
108using VisitorsDiagnosticsTy =
109 llvm::DenseMap<const ExplodedNode *, std::vector<PathDiagnosticPieceRef>>;
110
111/// A map from PathDiagnosticPiece to the LocationContext of the inlined
112/// function call it represents.
113using LocationContextMap =
114 llvm::DenseMap<const PathPieces *, const LocationContext *>;
115
116/// A helper class that contains everything needed to construct a
117/// PathDiagnostic object. It does no much more then providing convenient
118/// getters and some well placed asserts for extra security.
119class PathDiagnosticConstruct {
120 /// The consumer we're constructing the bug report for.
121 const PathDiagnosticConsumer *Consumer;
122 /// Our current position in the bug path, which is owned by
123 /// PathDiagnosticBuilder.
124 const ExplodedNode *CurrentNode;
125 /// A mapping from parts of the bug path (for example, a function call, which
126 /// would span backwards from a CallExit to a CallEnter with the nodes in
127 /// between them) with the location contexts it is associated with.
128 LocationContextMap LCM;
129 const SourceManager &SM;
130
131public:
132 /// We keep stack of calls to functions as we're ascending the bug path.
133 /// TODO: PathDiagnostic has a stack doing the same thing, shouldn't we use
134 /// that instead?
135 CallWithEntryStack CallStack;
136 /// The bug report we're constructing. For ease of use, this field is kept
137 /// public, though some "shortcut" getters are provided for commonly used
138 /// methods of PathDiagnostic.
139 std::unique_ptr<PathDiagnostic> PD;
140
141public:
142 PathDiagnosticConstruct(const PathDiagnosticConsumer *PDC,
143 const ExplodedNode *ErrorNode,
144 const PathSensitiveBugReport *R,
145 const Decl *AnalysisEntryPoint);
146
147 /// \returns the location context associated with the current position in the
148 /// bug path.
149 const LocationContext *getCurrLocationContext() const {
150 assert(CurrentNode && "Already reached the root!");
151 return CurrentNode->getLocationContext();
152 }
153
154 /// Same as getCurrLocationContext (they should always return the same
155 /// location context), but works after reaching the root of the bug path as
156 /// well.
157 const LocationContext *getLocationContextForActivePath() const {
158 return LCM.find(Val: &PD->getActivePath())->getSecond();
159 }
160
161 const ExplodedNode *getCurrentNode() const { return CurrentNode; }
162
163 /// Steps the current node to its predecessor.
164 /// \returns whether we reached the root of the bug path.
165 bool ascendToPrevNode() {
166 CurrentNode = CurrentNode->getFirstPred();
167 return static_cast<bool>(CurrentNode);
168 }
169
170 const ParentMap &getParentMap() const {
171 return getCurrLocationContext()->getParentMap();
172 }
173
174 const SourceManager &getSourceManager() const { return SM; }
175
176 const Stmt *getParent(const Stmt *S) const {
177 return getParentMap().getParent(S);
178 }
179
180 void updateLocCtxMap(const PathPieces *Path, const LocationContext *LC) {
181 assert(Path && LC);
182 LCM[Path] = LC;
183 }
184
185 const LocationContext *getLocationContextFor(const PathPieces *Path) const {
186 assert(LCM.count(Path) &&
187 "Failed to find the context associated with these pieces!");
188 return LCM.find(Val: Path)->getSecond();
189 }
190
191 bool isInLocCtxMap(const PathPieces *Path) const { return LCM.count(Val: Path); }
192
193 PathPieces &getActivePath() { return PD->getActivePath(); }
194 PathPieces &getMutablePieces() { return PD->getMutablePieces(); }
195
196 bool shouldAddPathEdges() const { return Consumer->shouldAddPathEdges(); }
197 bool shouldAddControlNotes() const {
198 return Consumer->shouldAddControlNotes();
199 }
200 bool shouldGenerateDiagnostics() const {
201 return Consumer->shouldGenerateDiagnostics();
202 }
203 bool supportsLogicalOpControlFlow() const {
204 return Consumer->supportsLogicalOpControlFlow();
205 }
206};
207
208/// Contains every contextual information needed for constructing a
209/// PathDiagnostic object for a given bug report. This class and its fields are
210/// immutable, and passes a BugReportConstruct object around during the
211/// construction.
212class PathDiagnosticBuilder : public BugReporterContext {
213 /// A linear path from the error node to the root.
214 std::unique_ptr<const ExplodedGraph> BugPath;
215 /// The bug report we're describing. Visitors create their diagnostics with
216 /// them being the last entities being able to modify it (for example,
217 /// changing interestingness here would cause inconsistencies as to how this
218 /// file and visitors construct diagnostics), hence its const.
219 const PathSensitiveBugReport *R;
220 /// The leaf of the bug path. This isn't the same as the bug reports error
221 /// node, which refers to the *original* graph, not the bug path.
222 const ExplodedNode *const ErrorNode;
223 /// The diagnostic pieces visitors emitted, which is expected to be collected
224 /// by the time this builder is constructed.
225 std::unique_ptr<const VisitorsDiagnosticsTy> VisitorsDiagnostics;
226
227public:
228 /// Find a non-invalidated report for a given equivalence class, and returns
229 /// a PathDiagnosticBuilder able to construct bug reports for different
230 /// consumers. Returns std::nullopt if no valid report is found.
231 static std::optional<PathDiagnosticBuilder>
232 findValidReport(ArrayRef<PathSensitiveBugReport *> &bugReports,
233 PathSensitiveBugReporter &Reporter);
234
235 PathDiagnosticBuilder(
236 BugReporterContext BRC, std::unique_ptr<ExplodedGraph> BugPath,
237 PathSensitiveBugReport *r, const ExplodedNode *ErrorNode,
238 std::unique_ptr<VisitorsDiagnosticsTy> VisitorsDiagnostics);
239
240 /// This function is responsible for generating diagnostic pieces that are
241 /// *not* provided by bug report visitors.
242 /// These diagnostics may differ depending on the consumer's settings,
243 /// and are therefore constructed separately for each consumer.
244 ///
245 /// There are two path diagnostics generation modes: with adding edges (used
246 /// for plists) and without (used for HTML and text). When edges are added,
247 /// the path is modified to insert artificially generated edges.
248 /// Otherwise, more detailed diagnostics is emitted for block edges,
249 /// explaining the transitions in words.
250 std::unique_ptr<PathDiagnostic>
251 generate(const PathDiagnosticConsumer *PDC) const;
252
253private:
254 void updateStackPiecesWithMessage(PathDiagnosticPieceRef P,
255 const CallWithEntryStack &CallStack) const;
256 void generatePathDiagnosticsForNode(PathDiagnosticConstruct &C,
257 PathDiagnosticLocation &PrevLoc) const;
258
259 void generateMinimalDiagForBlockEdge(PathDiagnosticConstruct &C,
260 BlockEdge BE) const;
261
262 PathDiagnosticPieceRef
263 generateDiagForGotoOP(const PathDiagnosticConstruct &C, const Stmt *S,
264 PathDiagnosticLocation &Start) const;
265
266 PathDiagnosticPieceRef
267 generateDiagForSwitchOP(const PathDiagnosticConstruct &C, const CFGBlock *Dst,
268 PathDiagnosticLocation &Start) const;
269
270 PathDiagnosticPieceRef
271 generateDiagForBinaryOP(const PathDiagnosticConstruct &C, const Stmt *T,
272 const CFGBlock *Src, const CFGBlock *DstC) const;
273
274 PathDiagnosticLocation
275 ExecutionContinues(const PathDiagnosticConstruct &C) const;
276
277 PathDiagnosticLocation
278 ExecutionContinues(llvm::raw_string_ostream &os,
279 const PathDiagnosticConstruct &C) const;
280
281 const PathSensitiveBugReport *getBugReport() const { return R; }
282};
283
284std::string timeTraceName(const BugReportEquivClass &EQ) {
285 if (!llvm::timeTraceProfilerEnabled())
286 return "";
287 const auto &BugReports = EQ.getReports();
288 if (BugReports.empty())
289 return "Empty Equivalence Class";
290 const BugReport *R = BugReports.front().get();
291 const auto &BT = R->getBugType();
292 return ("Flushing EQC " + BT.getDescription()).str();
293}
294
295llvm::TimeTraceMetadata timeTraceMetadata(const BugReportEquivClass &EQ,
296 const SourceManager &SM) {
297 // Must be called only when constructing non-bogus TimeTraceScope
298 assert(llvm::timeTraceProfilerEnabled());
299
300 const auto &BugReports = EQ.getReports();
301 if (BugReports.empty())
302 return {};
303 const BugReport *R = BugReports.front().get();
304 const auto &BT = R->getBugType();
305 auto Loc = R->getLocation().asLocation();
306 std::string File = SM.getFilename(SpellingLoc: Loc).str();
307 return {.Detail: BT.getCheckerName().str(), .File: std::move(File),
308 .Line: static_cast<int>(Loc.getLineNumber())};
309}
310
311} // namespace
312
313//===----------------------------------------------------------------------===//
314// Base implementation of stack hint generators.
315//===----------------------------------------------------------------------===//
316
317StackHintGenerator::~StackHintGenerator() = default;
318
319std::string StackHintGeneratorForSymbol::getMessage(const ExplodedNode *N){
320 if (!N)
321 return getMessageForSymbolNotFound();
322
323 ProgramPoint P = N->getLocation();
324 CallExitEnd CExit = P.castAs<CallExitEnd>();
325
326 // FIXME: Use CallEvent to abstract this over all calls.
327 const Stmt *CallSite = CExit.getCalleeContext()->getCallSite();
328 const auto *CE = dyn_cast_or_null<CallExpr>(Val: CallSite);
329 if (!CE)
330 return {};
331
332 // Check if one of the parameters are set to the interesting symbol.
333 for (auto [Idx, ArgExpr] : llvm::enumerate(First: CE->arguments())) {
334 SVal SV = N->getSVal(S: ArgExpr);
335
336 // Check if the variable corresponding to the symbol is passed by value.
337 SymbolRef AS = SV.getAsLocSymbol();
338 if (AS == Sym) {
339 return getMessageForArg(ArgE: ArgExpr, ArgIndex: Idx);
340 }
341
342 // Check if the parameter is a pointer to the symbol.
343 if (std::optional<loc::MemRegionVal> Reg = SV.getAs<loc::MemRegionVal>()) {
344 // Do not attempt to dereference void*.
345 if (ArgExpr->getType()->isVoidPointerType())
346 continue;
347 SVal PSV = N->getState()->getSVal(R: Reg->getRegion());
348 SymbolRef AS = PSV.getAsLocSymbol();
349 if (AS == Sym) {
350 return getMessageForArg(ArgE: ArgExpr, ArgIndex: Idx);
351 }
352 }
353 }
354
355 // Check if we are returning the interesting symbol.
356 SVal SV = N->getSVal(S: CE);
357 SymbolRef RetSym = SV.getAsLocSymbol();
358 if (RetSym == Sym) {
359 return getMessageForReturn(CallExpr: CE);
360 }
361
362 return getMessageForSymbolNotFound();
363}
364
365std::string StackHintGeneratorForSymbol::getMessageForArg(const Expr *ArgE,
366 unsigned ArgIndex) {
367 // Printed parameters start at 1, not 0.
368 ++ArgIndex;
369
370 return (llvm::Twine(Msg) + " via " + std::to_string(val: ArgIndex) +
371 llvm::getOrdinalSuffix(Val: ArgIndex) + " parameter").str();
372}
373
374//===----------------------------------------------------------------------===//
375// Diagnostic cleanup.
376//===----------------------------------------------------------------------===//
377
378static PathDiagnosticEventPiece *
379eventsDescribeSameCondition(PathDiagnosticEventPiece *X,
380 PathDiagnosticEventPiece *Y) {
381 // Prefer diagnostics that come from ConditionBRVisitor over
382 // those that came from TrackConstraintBRVisitor,
383 // unless the one from ConditionBRVisitor is
384 // its generic fallback diagnostic.
385 const void *tagPreferred = ConditionBRVisitor::getTag();
386 const void *tagLesser = TrackConstraintBRVisitor::getTag();
387
388 if (X->getLocation() != Y->getLocation())
389 return nullptr;
390
391 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
392 return ConditionBRVisitor::isPieceMessageGeneric(Piece: X) ? Y : X;
393
394 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
395 return ConditionBRVisitor::isPieceMessageGeneric(Piece: Y) ? X : Y;
396
397 return nullptr;
398}
399
400/// An optimization pass over PathPieces that removes redundant diagnostics
401/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both
402/// BugReporterVisitors use different methods to generate diagnostics, with
403/// one capable of emitting diagnostics in some cases but not in others. This
404/// can lead to redundant diagnostic pieces at the same point in a path.
405static void removeRedundantMsgs(PathPieces &path) {
406 unsigned N = path.size();
407 if (N < 2)
408 return;
409 // NOTE: this loop intentionally is not using an iterator. Instead, we
410 // are streaming the path and modifying it in place. This is done by
411 // grabbing the front, processing it, and if we decide to keep it append
412 // it to the end of the path. The entire path is processed in this way.
413 for (unsigned i = 0; i < N; ++i) {
414 auto piece = std::move(path.front());
415 path.pop_front();
416
417 switch (piece->getKind()) {
418 case PathDiagnosticPiece::Call:
419 removeRedundantMsgs(path&: cast<PathDiagnosticCallPiece>(Val&: *piece).path);
420 break;
421 case PathDiagnosticPiece::Macro:
422 removeRedundantMsgs(path&: cast<PathDiagnosticMacroPiece>(Val&: *piece).subPieces);
423 break;
424 case PathDiagnosticPiece::Event: {
425 if (i == N-1)
426 break;
427
428 if (auto *nextEvent =
429 dyn_cast<PathDiagnosticEventPiece>(Val: path.front().get())) {
430 auto *event = cast<PathDiagnosticEventPiece>(Val: piece.get());
431 // Check to see if we should keep one of the two pieces. If we
432 // come up with a preference, record which piece to keep, and consume
433 // another piece from the path.
434 if (auto *pieceToKeep =
435 eventsDescribeSameCondition(X: event, Y: nextEvent)) {
436 piece = std::move(pieceToKeep == event ? piece : path.front());
437 path.pop_front();
438 ++i;
439 }
440 }
441 break;
442 }
443 case PathDiagnosticPiece::ControlFlow:
444 case PathDiagnosticPiece::Note:
445 case PathDiagnosticPiece::PopUp:
446 break;
447 }
448 path.push_back(x: std::move(piece));
449 }
450}
451
452/// Recursively scan through a path and prune out calls and macros pieces
453/// that aren't needed. Return true if afterwards the path contains
454/// "interesting stuff" which means it shouldn't be pruned from the parent path.
455static bool removeUnneededCalls(const PathDiagnosticConstruct &C,
456 PathPieces &pieces,
457 const PathSensitiveBugReport *R,
458 bool IsInteresting = false) {
459 bool containsSomethingInteresting = IsInteresting;
460 const unsigned N = pieces.size();
461
462 for (unsigned i = 0 ; i < N ; ++i) {
463 // Remove the front piece from the path. If it is still something we
464 // want to keep once we are done, we will push it back on the end.
465 auto piece = std::move(pieces.front());
466 pieces.pop_front();
467
468 switch (piece->getKind()) {
469 case PathDiagnosticPiece::Call: {
470 auto &call = cast<PathDiagnosticCallPiece>(Val&: *piece);
471 // Check if the location context is interesting.
472 if (!removeUnneededCalls(
473 C, pieces&: call.path, R,
474 IsInteresting: R->isInteresting(LC: C.getLocationContextFor(Path: &call.path))))
475 continue;
476
477 containsSomethingInteresting = true;
478 break;
479 }
480 case PathDiagnosticPiece::Macro: {
481 auto &macro = cast<PathDiagnosticMacroPiece>(Val&: *piece);
482 if (!removeUnneededCalls(C, pieces&: macro.subPieces, R, IsInteresting))
483 continue;
484 containsSomethingInteresting = true;
485 break;
486 }
487 case PathDiagnosticPiece::Event: {
488 auto &event = cast<PathDiagnosticEventPiece>(Val&: *piece);
489
490 // We never throw away an event, but we do throw it away wholesale
491 // as part of a path if we throw the entire path away.
492 containsSomethingInteresting |= !event.isPrunable();
493 break;
494 }
495 case PathDiagnosticPiece::ControlFlow:
496 case PathDiagnosticPiece::Note:
497 case PathDiagnosticPiece::PopUp:
498 break;
499 }
500
501 pieces.push_back(x: std::move(piece));
502 }
503
504 return containsSomethingInteresting;
505}
506
507/// Same logic as above to remove extra pieces.
508static void removePopUpNotes(PathPieces &Path) {
509 for (unsigned int i = 0; i < Path.size(); ++i) {
510 auto Piece = std::move(Path.front());
511 Path.pop_front();
512 if (!isa<PathDiagnosticPopUpPiece>(Val: *Piece))
513 Path.push_back(x: std::move(Piece));
514 }
515}
516
517/// Returns true if the given decl has been implicitly given a body, either by
518/// the analyzer or by the compiler proper.
519static bool hasImplicitBody(const Decl *D) {
520 assert(D);
521 return D->isImplicit() || !D->hasBody();
522}
523
524/// Recursively scan through a path and make sure that all call pieces have
525/// valid locations.
526static void
527adjustCallLocations(PathPieces &Pieces,
528 PathDiagnosticLocation *LastCallLocation = nullptr) {
529 for (const auto &I : Pieces) {
530 auto *Call = dyn_cast<PathDiagnosticCallPiece>(Val: I.get());
531
532 if (!Call)
533 continue;
534
535 if (LastCallLocation) {
536 bool CallerIsImplicit = hasImplicitBody(D: Call->getCaller());
537 if (CallerIsImplicit || !Call->callEnter.asLocation().isValid())
538 Call->callEnter = *LastCallLocation;
539 if (CallerIsImplicit || !Call->callReturn.asLocation().isValid())
540 Call->callReturn = *LastCallLocation;
541 }
542
543 // Recursively clean out the subclass. Keep this call around if
544 // it contains any informative diagnostics.
545 PathDiagnosticLocation *ThisCallLocation;
546 if (Call->callEnterWithin.asLocation().isValid() &&
547 !hasImplicitBody(D: Call->getCallee()))
548 ThisCallLocation = &Call->callEnterWithin;
549 else
550 ThisCallLocation = &Call->callEnter;
551
552 assert(ThisCallLocation && "Outermost call has an invalid location");
553 adjustCallLocations(Pieces&: Call->path, LastCallLocation: ThisCallLocation);
554 }
555}
556
557/// Remove edges in and out of C++ default initializer expressions. These are
558/// for fields that have in-class initializers, as opposed to being initialized
559/// explicitly in a constructor or braced list.
560static void removeEdgesToDefaultInitializers(PathPieces &Pieces) {
561 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
562 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(Val: I->get()))
563 removeEdgesToDefaultInitializers(Pieces&: C->path);
564
565 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(Val: I->get()))
566 removeEdgesToDefaultInitializers(Pieces&: M->subPieces);
567
568 if (auto *CF = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get())) {
569 const Stmt *Start = CF->getStartLocation().asStmt();
570 const Stmt *End = CF->getEndLocation().asStmt();
571 if (isa_and_nonnull<CXXDefaultInitExpr>(Val: Start)) {
572 I = Pieces.erase(position: I);
573 continue;
574 } else if (isa_and_nonnull<CXXDefaultInitExpr>(Val: End)) {
575 PathPieces::iterator Next = std::next(x: I);
576 if (Next != E) {
577 if (auto *NextCF =
578 dyn_cast<PathDiagnosticControlFlowPiece>(Val: Next->get())) {
579 NextCF->setStartLocation(CF->getStartLocation());
580 }
581 }
582 I = Pieces.erase(position: I);
583 continue;
584 }
585 }
586
587 I++;
588 }
589}
590
591/// Remove all pieces with invalid locations as these cannot be serialized.
592/// We might have pieces with invalid locations as a result of inlining Body
593/// Farm generated functions.
594static void removePiecesWithInvalidLocations(PathPieces &Pieces) {
595 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
596 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(Val: I->get()))
597 removePiecesWithInvalidLocations(Pieces&: C->path);
598
599 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(Val: I->get()))
600 removePiecesWithInvalidLocations(Pieces&: M->subPieces);
601
602 if (!(*I)->getLocation().isValid() ||
603 !(*I)->getLocation().asLocation().isValid()) {
604 I = Pieces.erase(position: I);
605 continue;
606 }
607 I++;
608 }
609}
610
611PathDiagnosticLocation PathDiagnosticBuilder::ExecutionContinues(
612 const PathDiagnosticConstruct &C) const {
613 if (const Stmt *S = C.getCurrentNode()->getNextStmtForDiagnostics())
614 return PathDiagnosticLocation(S, getSourceManager(),
615 C.getCurrLocationContext());
616
617 return PathDiagnosticLocation::createDeclEnd(LC: C.getCurrLocationContext(),
618 SM: getSourceManager());
619}
620
621PathDiagnosticLocation PathDiagnosticBuilder::ExecutionContinues(
622 llvm::raw_string_ostream &os, const PathDiagnosticConstruct &C) const {
623 // Slow, but probably doesn't matter.
624 if (os.str().empty())
625 os << ' ';
626
627 const PathDiagnosticLocation &Loc = ExecutionContinues(C);
628
629 if (Loc.asStmt())
630 os << "Execution continues on line "
631 << getSourceManager().getExpansionLineNumber(Loc: Loc.asLocation())
632 << '.';
633 else {
634 os << "Execution jumps to the end of the ";
635 const Decl *D = C.getCurrLocationContext()->getDecl();
636 if (isa<ObjCMethodDecl>(Val: D))
637 os << "method";
638 else if (isa<FunctionDecl>(Val: D))
639 os << "function";
640 else {
641 assert(isa<BlockDecl>(D));
642 os << "anonymous block";
643 }
644 os << '.';
645 }
646
647 return Loc;
648}
649
650static const Stmt *getEnclosingParent(const Stmt *S, const ParentMap &PM) {
651 if (isa<Expr>(Val: S) && PM.isConsumedExpr(E: cast<Expr>(Val: S)))
652 return PM.getParentIgnoreParens(S);
653
654 const Stmt *Parent = PM.getParentIgnoreParens(S);
655 if (!Parent)
656 return nullptr;
657
658 switch (Parent->getStmtClass()) {
659 case Stmt::ForStmtClass:
660 case Stmt::DoStmtClass:
661 case Stmt::WhileStmtClass:
662 case Stmt::ObjCForCollectionStmtClass:
663 case Stmt::CXXForRangeStmtClass:
664 return Parent;
665 default:
666 break;
667 }
668
669 return nullptr;
670}
671
672static PathDiagnosticLocation
673getEnclosingStmtLocation(const Stmt *S, const LocationContext *LC,
674 bool allowNestedContexts = false) {
675 if (!S)
676 return {};
677
678 const SourceManager &SMgr = LC->getDecl()->getASTContext().getSourceManager();
679
680 while (const Stmt *Parent = getEnclosingParent(S, PM: LC->getParentMap())) {
681 switch (Parent->getStmtClass()) {
682 case Stmt::BinaryOperatorClass: {
683 const auto *B = cast<BinaryOperator>(Val: Parent);
684 if (B->isLogicalOp())
685 return PathDiagnosticLocation(allowNestedContexts ? B : S, SMgr, LC);
686 break;
687 }
688 case Stmt::CompoundStmtClass:
689 case Stmt::StmtExprClass:
690 return PathDiagnosticLocation(S, SMgr, LC);
691 case Stmt::ChooseExprClass:
692 // Similar to '?' if we are referring to condition, just have the edge
693 // point to the entire choose expression.
694 if (allowNestedContexts || cast<ChooseExpr>(Val: Parent)->getCond() == S)
695 return PathDiagnosticLocation(Parent, SMgr, LC);
696 else
697 return PathDiagnosticLocation(S, SMgr, LC);
698 case Stmt::BinaryConditionalOperatorClass:
699 case Stmt::ConditionalOperatorClass:
700 // For '?', if we are referring to condition, just have the edge point
701 // to the entire '?' expression.
702 if (allowNestedContexts ||
703 cast<AbstractConditionalOperator>(Val: Parent)->getCond() == S)
704 return PathDiagnosticLocation(Parent, SMgr, LC);
705 else
706 return PathDiagnosticLocation(S, SMgr, LC);
707 case Stmt::CXXForRangeStmtClass:
708 if (cast<CXXForRangeStmt>(Val: Parent)->getBody() == S)
709 return PathDiagnosticLocation(S, SMgr, LC);
710 break;
711 case Stmt::DoStmtClass:
712 return PathDiagnosticLocation(S, SMgr, LC);
713 case Stmt::ForStmtClass:
714 if (cast<ForStmt>(Val: Parent)->getBody() == S)
715 return PathDiagnosticLocation(S, SMgr, LC);
716 break;
717 case Stmt::IfStmtClass:
718 if (cast<IfStmt>(Val: Parent)->getCond() != S)
719 return PathDiagnosticLocation(S, SMgr, LC);
720 break;
721 case Stmt::ObjCForCollectionStmtClass:
722 if (cast<ObjCForCollectionStmt>(Val: Parent)->getBody() == S)
723 return PathDiagnosticLocation(S, SMgr, LC);
724 break;
725 case Stmt::WhileStmtClass:
726 if (cast<WhileStmt>(Val: Parent)->getCond() != S)
727 return PathDiagnosticLocation(S, SMgr, LC);
728 break;
729 default:
730 break;
731 }
732
733 S = Parent;
734 }
735
736 assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
737
738 return PathDiagnosticLocation(S, SMgr, LC);
739}
740
741//===----------------------------------------------------------------------===//
742// "Minimal" path diagnostic generation algorithm.
743//===----------------------------------------------------------------------===//
744
745/// If the piece contains a special message, add it to all the call pieces on
746/// the active stack. For example, my_malloc allocated memory, so MallocChecker
747/// will construct an event at the call to malloc(), and add a stack hint that
748/// an allocated memory was returned. We'll use this hint to construct a message
749/// when returning from the call to my_malloc
750///
751/// void *my_malloc() { return malloc(sizeof(int)); }
752/// void fishy() {
753/// void *ptr = my_malloc(); // returned allocated memory
754/// } // leak
755void PathDiagnosticBuilder::updateStackPiecesWithMessage(
756 PathDiagnosticPieceRef P, const CallWithEntryStack &CallStack) const {
757 if (R->hasCallStackHint(Piece: P))
758 for (const auto &I : CallStack) {
759 PathDiagnosticCallPiece *CP = I.first;
760 const ExplodedNode *N = I.second;
761 std::string stackMsg = R->getCallStackMessage(Piece: P, N);
762
763 // The last message on the path to final bug is the most important
764 // one. Since we traverse the path backwards, do not add the message
765 // if one has been previously added.
766 if (!CP->hasCallStackMessage())
767 CP->setCallStackMessage(stackMsg);
768 }
769}
770
771static void CompactMacroExpandedPieces(PathPieces &path,
772 const SourceManager& SM);
773
774PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForSwitchOP(
775 const PathDiagnosticConstruct &C, const CFGBlock *Dst,
776 PathDiagnosticLocation &Start) const {
777
778 const SourceManager &SM = getSourceManager();
779 // Figure out what case arm we took.
780 std::string sbuf;
781 llvm::raw_string_ostream os(sbuf);
782 PathDiagnosticLocation End;
783
784 if (const Stmt *S = Dst->getLabel()) {
785 End = PathDiagnosticLocation(S, SM, C.getCurrLocationContext());
786
787 switch (S->getStmtClass()) {
788 default:
789 os << "No cases match in the switch statement. "
790 "Control jumps to line "
791 << End.asLocation().getExpansionLineNumber();
792 break;
793 case Stmt::DefaultStmtClass:
794 os << "Control jumps to the 'default' case at line "
795 << End.asLocation().getExpansionLineNumber();
796 break;
797
798 case Stmt::CaseStmtClass: {
799 os << "Control jumps to 'case ";
800 const auto *Case = cast<CaseStmt>(Val: S);
801 const Expr *LHS = Case->getLHS()->IgnoreParenImpCasts();
802
803 // Determine if it is an enum.
804 bool GetRawInt = true;
805
806 if (const auto *DR = dyn_cast<DeclRefExpr>(Val: LHS)) {
807 // FIXME: Maybe this should be an assertion. Are there cases
808 // were it is not an EnumConstantDecl?
809 const auto *D = dyn_cast<EnumConstantDecl>(Val: DR->getDecl());
810
811 if (D) {
812 GetRawInt = false;
813 os << *D;
814 }
815 }
816
817 if (GetRawInt)
818 os << LHS->EvaluateKnownConstInt(Ctx: getASTContext());
819
820 os << ":' at line " << End.asLocation().getExpansionLineNumber();
821 break;
822 }
823 }
824 } else {
825 os << "'Default' branch taken. ";
826 End = ExecutionContinues(os, C);
827 }
828 return std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf);
829}
830
831PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForGotoOP(
832 const PathDiagnosticConstruct &C, const Stmt *S,
833 PathDiagnosticLocation &Start) const {
834 std::string sbuf;
835 llvm::raw_string_ostream os(sbuf);
836 const PathDiagnosticLocation &End =
837 getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
838 os << "Control jumps to line " << End.asLocation().getExpansionLineNumber();
839 return std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args: End, args&: sbuf);
840}
841
842PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForBinaryOP(
843 const PathDiagnosticConstruct &C, const Stmt *T, const CFGBlock *Src,
844 const CFGBlock *Dst) const {
845
846 const SourceManager &SM = getSourceManager();
847
848 const auto *B = cast<BinaryOperator>(Val: T);
849 std::string sbuf;
850 llvm::raw_string_ostream os(sbuf);
851 os << "Left side of '";
852 PathDiagnosticLocation Start, End;
853
854 if (B->getOpcode() == BO_LAnd) {
855 os << "&&"
856 << "' is ";
857
858 if (*(Src->succ_begin() + 1) == Dst) {
859 os << "false";
860 End = PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
861 Start =
862 PathDiagnosticLocation::createOperatorLoc(BO: B, SM);
863 } else {
864 os << "true";
865 Start =
866 PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
867 End = ExecutionContinues(C);
868 }
869 } else {
870 assert(B->getOpcode() == BO_LOr);
871 os << "||"
872 << "' is ";
873
874 if (*(Src->succ_begin() + 1) == Dst) {
875 os << "false";
876 Start =
877 PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
878 End = ExecutionContinues(C);
879 } else {
880 os << "true";
881 End = PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext());
882 Start =
883 PathDiagnosticLocation::createOperatorLoc(BO: B, SM);
884 }
885 }
886 return std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf);
887}
888
889void PathDiagnosticBuilder::generateMinimalDiagForBlockEdge(
890 PathDiagnosticConstruct &C, BlockEdge BE) const {
891 const SourceManager &SM = getSourceManager();
892 const LocationContext *LC = C.getCurrLocationContext();
893 const CFGBlock *Src = BE.getSrc();
894 const CFGBlock *Dst = BE.getDst();
895 const Stmt *T = Src->getTerminatorStmt();
896 if (!T)
897 return;
898
899 auto Start = PathDiagnosticLocation::createBegin(S: T, SM, LAC: LC);
900 switch (T->getStmtClass()) {
901 default:
902 break;
903
904 case Stmt::GotoStmtClass:
905 case Stmt::IndirectGotoStmtClass: {
906 if (const Stmt *S = C.getCurrentNode()->getNextStmtForDiagnostics())
907 C.getActivePath().push_front(x: generateDiagForGotoOP(C, S, Start));
908 break;
909 }
910
911 case Stmt::SwitchStmtClass: {
912 C.getActivePath().push_front(x: generateDiagForSwitchOP(C, Dst, Start));
913 break;
914 }
915
916 case Stmt::BreakStmtClass:
917 case Stmt::ContinueStmtClass: {
918 std::string sbuf;
919 llvm::raw_string_ostream os(sbuf);
920 PathDiagnosticLocation End = ExecutionContinues(os, C);
921 C.getActivePath().push_front(
922 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
923 break;
924 }
925
926 // Determine control-flow for ternary '?'.
927 case Stmt::BinaryConditionalOperatorClass:
928 case Stmt::ConditionalOperatorClass: {
929 std::string sbuf;
930 llvm::raw_string_ostream os(sbuf);
931 os << "'?' condition is ";
932
933 if (*(Src->succ_begin() + 1) == Dst)
934 os << "false";
935 else
936 os << "true";
937
938 PathDiagnosticLocation End = ExecutionContinues(C);
939
940 if (const Stmt *S = End.asStmt())
941 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
942
943 C.getActivePath().push_front(
944 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
945 break;
946 }
947
948 // Determine control-flow for short-circuited '&&' and '||'.
949 case Stmt::BinaryOperatorClass: {
950 if (!C.supportsLogicalOpControlFlow())
951 break;
952
953 C.getActivePath().push_front(x: generateDiagForBinaryOP(C, T, Src, Dst));
954 break;
955 }
956
957 case Stmt::DoStmtClass:
958 if (*(Src->succ_begin()) == Dst) {
959 std::string sbuf;
960 llvm::raw_string_ostream os(sbuf);
961
962 os << "Loop condition is true. ";
963 PathDiagnosticLocation End = ExecutionContinues(os, C);
964
965 if (const Stmt *S = End.asStmt())
966 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
967
968 C.getActivePath().push_front(
969 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
970 } else {
971 PathDiagnosticLocation End = ExecutionContinues(C);
972
973 if (const Stmt *S = End.asStmt())
974 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
975
976 C.getActivePath().push_front(
977 x: std::make_shared<PathDiagnosticControlFlowPiece>(
978 args&: Start, args&: End, args: "Loop condition is false. Exiting loop"));
979 }
980 break;
981
982 case Stmt::WhileStmtClass:
983 case Stmt::ForStmtClass:
984 if (*(Src->succ_begin() + 1) == Dst) {
985 std::string sbuf;
986 llvm::raw_string_ostream os(sbuf);
987
988 os << "Loop condition is false. ";
989 PathDiagnosticLocation End = ExecutionContinues(os, C);
990 if (const Stmt *S = End.asStmt())
991 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
992
993 C.getActivePath().push_front(
994 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: Start, args&: End, args&: sbuf));
995 } else {
996 PathDiagnosticLocation End = ExecutionContinues(C);
997 if (const Stmt *S = End.asStmt())
998 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
999
1000 C.getActivePath().push_front(
1001 x: std::make_shared<PathDiagnosticControlFlowPiece>(
1002 args&: Start, args&: End, args: "Loop condition is true. Entering loop body"));
1003 }
1004
1005 break;
1006
1007 case Stmt::IfStmtClass: {
1008 PathDiagnosticLocation End = ExecutionContinues(C);
1009
1010 if (const Stmt *S = End.asStmt())
1011 End = getEnclosingStmtLocation(S, LC: C.getCurrLocationContext());
1012
1013 if (*(Src->succ_begin() + 1) == Dst)
1014 C.getActivePath().push_front(
1015 x: std::make_shared<PathDiagnosticControlFlowPiece>(
1016 args&: Start, args&: End, args: "Taking false branch"));
1017 else
1018 C.getActivePath().push_front(
1019 x: std::make_shared<PathDiagnosticControlFlowPiece>(
1020 args&: Start, args&: End, args: "Taking true branch"));
1021
1022 break;
1023 }
1024 }
1025}
1026
1027//===----------------------------------------------------------------------===//
1028// Functions for determining if a loop was executed 0 times.
1029//===----------------------------------------------------------------------===//
1030
1031static bool isLoop(const Stmt *Term) {
1032 switch (Term->getStmtClass()) {
1033 case Stmt::ForStmtClass:
1034 case Stmt::WhileStmtClass:
1035 case Stmt::ObjCForCollectionStmtClass:
1036 case Stmt::CXXForRangeStmtClass:
1037 return true;
1038 default:
1039 // Note that we intentionally do not include do..while here.
1040 return false;
1041 }
1042}
1043
1044static bool isJumpToFalseBranch(const BlockEdge *BE) {
1045 const CFGBlock *Src = BE->getSrc();
1046 assert(Src->succ_size() == 2);
1047 return (*(Src->succ_begin()+1) == BE->getDst());
1048}
1049
1050static bool isContainedByStmt(const ParentMap &PM, const Stmt *S,
1051 const Stmt *SubS) {
1052 while (SubS) {
1053 if (SubS == S)
1054 return true;
1055 SubS = PM.getParent(S: SubS);
1056 }
1057 return false;
1058}
1059
1060static const Stmt *getStmtBeforeCond(const ParentMap &PM, const Stmt *Term,
1061 const ExplodedNode *N) {
1062 while (N) {
1063 std::optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>();
1064 if (SP) {
1065 const Stmt *S = SP->getStmt();
1066 if (!isContainedByStmt(PM, S: Term, SubS: S))
1067 return S;
1068 }
1069 N = N->getFirstPred();
1070 }
1071 return nullptr;
1072}
1073
1074static bool isInLoopBody(const ParentMap &PM, const Stmt *S, const Stmt *Term) {
1075 const Stmt *LoopBody = nullptr;
1076 switch (Term->getStmtClass()) {
1077 case Stmt::CXXForRangeStmtClass: {
1078 const auto *FR = cast<CXXForRangeStmt>(Val: Term);
1079 if (isContainedByStmt(PM, S: FR->getInc(), SubS: S))
1080 return true;
1081 if (isContainedByStmt(PM, S: FR->getLoopVarStmt(), SubS: S))
1082 return true;
1083 LoopBody = FR->getBody();
1084 break;
1085 }
1086 case Stmt::ForStmtClass: {
1087 const auto *FS = cast<ForStmt>(Val: Term);
1088 if (isContainedByStmt(PM, S: FS->getInc(), SubS: S))
1089 return true;
1090 LoopBody = FS->getBody();
1091 break;
1092 }
1093 case Stmt::ObjCForCollectionStmtClass: {
1094 const auto *FC = cast<ObjCForCollectionStmt>(Val: Term);
1095 LoopBody = FC->getBody();
1096 break;
1097 }
1098 case Stmt::WhileStmtClass:
1099 LoopBody = cast<WhileStmt>(Val: Term)->getBody();
1100 break;
1101 default:
1102 return false;
1103 }
1104 return isContainedByStmt(PM, S: LoopBody, SubS: S);
1105}
1106
1107/// Adds a sanitized control-flow diagnostic edge to a path.
1108static void addEdgeToPath(PathPieces &path,
1109 PathDiagnosticLocation &PrevLoc,
1110 PathDiagnosticLocation NewLoc) {
1111 if (!NewLoc.isValid())
1112 return;
1113
1114 SourceLocation NewLocL = NewLoc.asLocation();
1115 if (NewLocL.isInvalid())
1116 return;
1117
1118 if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) {
1119 PrevLoc = NewLoc;
1120 return;
1121 }
1122
1123 // Ignore self-edges, which occur when there are multiple nodes at the same
1124 // statement.
1125 if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt())
1126 return;
1127
1128 path.push_front(
1129 x: std::make_shared<PathDiagnosticControlFlowPiece>(args&: NewLoc, args&: PrevLoc));
1130 PrevLoc = NewLoc;
1131}
1132
1133/// A customized wrapper for CFGBlock::getTerminatorCondition()
1134/// which returns the element for ObjCForCollectionStmts.
1135static const Stmt *getTerminatorCondition(const CFGBlock *B) {
1136 const Stmt *S = B->getTerminatorCondition();
1137 if (const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(Val: S))
1138 return FS->getElement();
1139 return S;
1140}
1141
1142constexpr llvm::StringLiteral StrEnteringLoop = "Entering loop body";
1143constexpr llvm::StringLiteral StrLoopBodyZero = "Loop body executed 0 times";
1144constexpr llvm::StringLiteral StrLoopRangeEmpty =
1145 "Loop body skipped when range is empty";
1146constexpr llvm::StringLiteral StrLoopCollectionEmpty =
1147 "Loop body skipped when collection is empty";
1148
1149static std::unique_ptr<FilesToLineNumsMap>
1150findExecutedLines(const SourceManager &SM, const ExplodedNode *N);
1151
1152void PathDiagnosticBuilder::generatePathDiagnosticsForNode(
1153 PathDiagnosticConstruct &C, PathDiagnosticLocation &PrevLoc) const {
1154 ProgramPoint P = C.getCurrentNode()->getLocation();
1155 const SourceManager &SM = getSourceManager();
1156
1157 // Have we encountered an entrance to a call? It may be
1158 // the case that we have not encountered a matching
1159 // call exit before this point. This means that the path
1160 // terminated within the call itself.
1161 if (auto CE = P.getAs<CallEnter>()) {
1162
1163 if (C.shouldAddPathEdges()) {
1164 // Add an edge to the start of the function.
1165 const StackFrameContext *CalleeLC = CE->getCalleeContext();
1166 const Decl *D = CalleeLC->getDecl();
1167 // Add the edge only when the callee has body. We jump to the beginning
1168 // of the *declaration*, however we expect it to be followed by the
1169 // body. This isn't the case for autosynthesized property accessors in
1170 // Objective-C. No need for a similar extra check for CallExit points
1171 // because the exit edge comes from a statement (i.e. return),
1172 // not from declaration.
1173 if (D->hasBody())
1174 addEdgeToPath(path&: C.getActivePath(), PrevLoc,
1175 NewLoc: PathDiagnosticLocation::createBegin(D, SM));
1176 }
1177
1178 // Did we visit an entire call?
1179 bool VisitedEntireCall = C.PD->isWithinCall();
1180 C.PD->popActivePath();
1181
1182 PathDiagnosticCallPiece *Call;
1183 if (VisitedEntireCall) {
1184 Call = cast<PathDiagnosticCallPiece>(Val: C.getActivePath().front().get());
1185 } else {
1186 // The path terminated within a nested location context, create a new
1187 // call piece to encapsulate the rest of the path pieces.
1188 const Decl *Caller = CE->getLocationContext()->getDecl();
1189 Call = PathDiagnosticCallPiece::construct(pieces&: C.getActivePath(), caller: Caller);
1190 assert(C.getActivePath().size() == 1 &&
1191 C.getActivePath().front().get() == Call);
1192
1193 // Since we just transferred the path over to the call piece, reset the
1194 // mapping of the active path to the current location context.
1195 assert(C.isInLocCtxMap(&C.getActivePath()) &&
1196 "When we ascend to a previously unvisited call, the active path's "
1197 "address shouldn't change, but rather should be compacted into "
1198 "a single CallEvent!");
1199 C.updateLocCtxMap(Path: &C.getActivePath(), LC: C.getCurrLocationContext());
1200
1201 // Record the location context mapping for the path within the call.
1202 assert(!C.isInLocCtxMap(&Call->path) &&
1203 "When we ascend to a previously unvisited call, this must be the "
1204 "first time we encounter the caller context!");
1205 C.updateLocCtxMap(Path: &Call->path, LC: CE->getCalleeContext());
1206 }
1207 Call->setCallee(CE: *CE, SM);
1208
1209 // Update the previous location in the active path.
1210 PrevLoc = Call->getLocation();
1211
1212 if (!C.CallStack.empty()) {
1213 assert(C.CallStack.back().first == Call);
1214 C.CallStack.pop_back();
1215 }
1216 return;
1217 }
1218
1219 assert(C.getCurrLocationContext() == C.getLocationContextForActivePath() &&
1220 "The current position in the bug path is out of sync with the "
1221 "location context associated with the active path!");
1222
1223 // Have we encountered an exit from a function call?
1224 if (std::optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
1225
1226 // We are descending into a call (backwards). Construct
1227 // a new call piece to contain the path pieces for that call.
1228 auto Call = PathDiagnosticCallPiece::construct(CE: *CE, SM);
1229 // Record the mapping from call piece to LocationContext.
1230 assert(!C.isInLocCtxMap(&Call->path) &&
1231 "We just entered a call, this must've been the first time we "
1232 "encounter its context!");
1233 C.updateLocCtxMap(Path: &Call->path, LC: CE->getCalleeContext());
1234
1235 if (C.shouldAddPathEdges()) {
1236 // Add the edge to the return site.
1237 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: Call->callReturn);
1238 PrevLoc.invalidate();
1239 }
1240
1241 auto *P = Call.get();
1242 C.getActivePath().push_front(x: std::move(Call));
1243
1244 // Make the contents of the call the active path for now.
1245 C.PD->pushActivePath(p: &P->path);
1246 C.CallStack.push_back(Elt: CallWithEntry(P, C.getCurrentNode()));
1247 return;
1248 }
1249
1250 if (auto PS = P.getAs<PostStmt>()) {
1251 if (!C.shouldAddPathEdges())
1252 return;
1253
1254 // Add an edge. If this is an ObjCForCollectionStmt do
1255 // not add an edge here as it appears in the CFG both
1256 // as a terminator and as a terminator condition.
1257 if (!isa<ObjCForCollectionStmt>(Val: PS->getStmt())) {
1258 PathDiagnosticLocation L =
1259 PathDiagnosticLocation(PS->getStmt(), SM, C.getCurrLocationContext());
1260 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: L);
1261 }
1262
1263 } else if (auto BE = P.getAs<BlockEdge>()) {
1264
1265 if (C.shouldAddControlNotes()) {
1266 generateMinimalDiagForBlockEdge(C, BE: *BE);
1267 }
1268
1269 if (!C.shouldAddPathEdges()) {
1270 return;
1271 }
1272
1273 // Are we jumping to the head of a loop? Add a special diagnostic.
1274 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
1275 PathDiagnosticLocation L(Loop, SM, C.getCurrLocationContext());
1276 const Stmt *Body = nullptr;
1277
1278 if (const auto *FS = dyn_cast<ForStmt>(Val: Loop))
1279 Body = FS->getBody();
1280 else if (const auto *WS = dyn_cast<WhileStmt>(Val: Loop))
1281 Body = WS->getBody();
1282 else if (const auto *OFS = dyn_cast<ObjCForCollectionStmt>(Val: Loop)) {
1283 Body = OFS->getBody();
1284 } else if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Val: Loop)) {
1285 Body = FRS->getBody();
1286 }
1287 // do-while statements are explicitly excluded here
1288
1289 auto p = std::make_shared<PathDiagnosticEventPiece>(
1290 args&: L, args: "Looping back to the head of the loop");
1291 p->setPrunable(isPrunable: true);
1292
1293 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: p->getLocation());
1294 // We might've added a very similar control node already
1295 if (!C.shouldAddControlNotes()) {
1296 C.getActivePath().push_front(x: std::move(p));
1297 }
1298
1299 if (const auto *CS = dyn_cast_or_null<CompoundStmt>(Val: Body)) {
1300 addEdgeToPath(path&: C.getActivePath(), PrevLoc,
1301 NewLoc: PathDiagnosticLocation::createEndBrace(CS, SM));
1302 }
1303 }
1304
1305 const CFGBlock *BSrc = BE->getSrc();
1306 const ParentMap &PM = C.getParentMap();
1307
1308 if (const Stmt *Term = BSrc->getTerminatorStmt()) {
1309 // Are we jumping past the loop body without ever executing the
1310 // loop (because the condition was false)?
1311 if (isLoop(Term)) {
1312 const Stmt *TermCond = getTerminatorCondition(B: BSrc);
1313 bool IsInLoopBody = isInLoopBody(
1314 PM, S: getStmtBeforeCond(PM, Term: TermCond, N: C.getCurrentNode()), Term);
1315
1316 StringRef str;
1317
1318 if (isJumpToFalseBranch(BE: &*BE)) {
1319 if (!IsInLoopBody) {
1320 if (isa<ObjCForCollectionStmt>(Val: Term)) {
1321 str = StrLoopCollectionEmpty;
1322 } else if (isa<CXXForRangeStmt>(Val: Term)) {
1323 str = StrLoopRangeEmpty;
1324 } else {
1325 str = StrLoopBodyZero;
1326 }
1327 }
1328 } else {
1329 str = StrEnteringLoop;
1330 }
1331
1332 if (!str.empty()) {
1333 PathDiagnosticLocation L(TermCond ? TermCond : Term, SM,
1334 C.getCurrLocationContext());
1335 auto PE = std::make_shared<PathDiagnosticEventPiece>(args&: L, args&: str);
1336 PE->setPrunable(isPrunable: true);
1337 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: PE->getLocation());
1338
1339 // We might've added a very similar control node already
1340 if (!C.shouldAddControlNotes()) {
1341 C.getActivePath().push_front(x: std::move(PE));
1342 }
1343 }
1344 } else if (isa<BreakStmt, ContinueStmt, GotoStmt>(Val: Term)) {
1345 PathDiagnosticLocation L(Term, SM, C.getCurrLocationContext());
1346 addEdgeToPath(path&: C.getActivePath(), PrevLoc, NewLoc: L);
1347 }
1348 }
1349 }
1350}
1351
1352static std::unique_ptr<PathDiagnostic>
1353generateDiagnosticForBasicReport(const BasicBugReport *R,
1354 const Decl *AnalysisEntryPoint) {
1355 const BugType &BT = R->getBugType();
1356 return std::make_unique<PathDiagnostic>(
1357 args: BT.getCheckerName(), args: R->getDeclWithIssue(), args: BT.getDescription(),
1358 args: R->getDescription(), args: R->getShortDescription(/*UseFallback=*/false),
1359 args: BT.getCategory(), args: R->getUniqueingLocation(), args: R->getUniqueingDecl(),
1360 args&: AnalysisEntryPoint, args: std::make_unique<FilesToLineNumsMap>());
1361}
1362
1363static std::unique_ptr<PathDiagnostic>
1364generateEmptyDiagnosticForReport(const PathSensitiveBugReport *R,
1365 const SourceManager &SM,
1366 const Decl *AnalysisEntryPoint) {
1367 const BugType &BT = R->getBugType();
1368 return std::make_unique<PathDiagnostic>(
1369 args: BT.getCheckerName(), args: R->getDeclWithIssue(), args: BT.getDescription(),
1370 args: R->getDescription(), args: R->getShortDescription(/*UseFallback=*/false),
1371 args: BT.getCategory(), args: R->getUniqueingLocation(), args: R->getUniqueingDecl(),
1372 args&: AnalysisEntryPoint, args: findExecutedLines(SM, N: R->getErrorNode()));
1373}
1374
1375static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) {
1376 if (!S)
1377 return nullptr;
1378
1379 while (true) {
1380 S = PM.getParentIgnoreParens(S);
1381
1382 if (!S)
1383 break;
1384
1385 if (isa<FullExpr, CXXBindTemporaryExpr, SubstNonTypeTemplateParmExpr>(Val: S))
1386 continue;
1387
1388 break;
1389 }
1390
1391 return S;
1392}
1393
1394static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) {
1395 switch (S->getStmtClass()) {
1396 case Stmt::BinaryOperatorClass: {
1397 const auto *BO = cast<BinaryOperator>(Val: S);
1398 if (!BO->isLogicalOp())
1399 return false;
1400 return BO->getLHS() == Cond || BO->getRHS() == Cond;
1401 }
1402 case Stmt::IfStmtClass:
1403 return cast<IfStmt>(Val: S)->getCond() == Cond;
1404 case Stmt::ForStmtClass:
1405 return cast<ForStmt>(Val: S)->getCond() == Cond;
1406 case Stmt::WhileStmtClass:
1407 return cast<WhileStmt>(Val: S)->getCond() == Cond;
1408 case Stmt::DoStmtClass:
1409 return cast<DoStmt>(Val: S)->getCond() == Cond;
1410 case Stmt::ChooseExprClass:
1411 return cast<ChooseExpr>(Val: S)->getCond() == Cond;
1412 case Stmt::IndirectGotoStmtClass:
1413 return cast<IndirectGotoStmt>(Val: S)->getTarget() == Cond;
1414 case Stmt::SwitchStmtClass:
1415 return cast<SwitchStmt>(Val: S)->getCond() == Cond;
1416 case Stmt::BinaryConditionalOperatorClass:
1417 return cast<BinaryConditionalOperator>(Val: S)->getCond() == Cond;
1418 case Stmt::ConditionalOperatorClass: {
1419 const auto *CO = cast<ConditionalOperator>(Val: S);
1420 return CO->getCond() == Cond ||
1421 CO->getLHS() == Cond ||
1422 CO->getRHS() == Cond;
1423 }
1424 case Stmt::ObjCForCollectionStmtClass:
1425 return cast<ObjCForCollectionStmt>(Val: S)->getElement() == Cond;
1426 case Stmt::CXXForRangeStmtClass: {
1427 const auto *FRS = cast<CXXForRangeStmt>(Val: S);
1428 return FRS->getCond() == Cond || FRS->getRangeInit() == Cond;
1429 }
1430 default:
1431 return false;
1432 }
1433}
1434
1435static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) {
1436 if (const auto *FS = dyn_cast<ForStmt>(Val: FL))
1437 return FS->getInc() == S || FS->getInit() == S;
1438 if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Val: FL))
1439 return FRS->getInc() == S || FRS->getRangeStmt() == S ||
1440 FRS->getLoopVarStmt() || FRS->getRangeInit() == S;
1441 return false;
1442}
1443
1444using OptimizedCallsSet = llvm::DenseSet<const PathDiagnosticCallPiece *>;
1445
1446/// Adds synthetic edges from top-level statements to their subexpressions.
1447///
1448/// This avoids a "swoosh" effect, where an edge from a top-level statement A
1449/// points to a sub-expression B.1 that's not at the start of B. In these cases,
1450/// we'd like to see an edge from A to B, then another one from B to B.1.
1451static void addContextEdges(PathPieces &pieces, const LocationContext *LC) {
1452 const ParentMap &PM = LC->getParentMap();
1453 PathPieces::iterator Prev = pieces.end();
1454 for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E;
1455 Prev = I, ++I) {
1456 auto *Piece = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1457
1458 if (!Piece)
1459 continue;
1460
1461 PathDiagnosticLocation SrcLoc = Piece->getStartLocation();
1462 SmallVector<PathDiagnosticLocation, 4> SrcContexts;
1463
1464 PathDiagnosticLocation NextSrcContext = SrcLoc;
1465 const Stmt *InnerStmt = nullptr;
1466 while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) {
1467 SrcContexts.push_back(Elt: NextSrcContext);
1468 InnerStmt = NextSrcContext.asStmt();
1469 NextSrcContext = getEnclosingStmtLocation(S: InnerStmt, LC,
1470 /*allowNested=*/allowNestedContexts: true);
1471 }
1472
1473 // Repeatedly split the edge as necessary.
1474 // This is important for nested logical expressions (||, &&, ?:) where we
1475 // want to show all the levels of context.
1476 while (true) {
1477 const Stmt *Dst = Piece->getEndLocation().getStmtOrNull();
1478
1479 // We are looking at an edge. Is the destination within a larger
1480 // expression?
1481 PathDiagnosticLocation DstContext =
1482 getEnclosingStmtLocation(S: Dst, LC, /*allowNested=*/allowNestedContexts: true);
1483 if (!DstContext.isValid() || DstContext.asStmt() == Dst)
1484 break;
1485
1486 // If the source is in the same context, we're already good.
1487 if (llvm::is_contained(Range&: SrcContexts, Element: DstContext))
1488 break;
1489
1490 // Update the subexpression node to point to the context edge.
1491 Piece->setStartLocation(DstContext);
1492
1493 // Try to extend the previous edge if it's at the same level as the source
1494 // context.
1495 if (Prev != E) {
1496 auto *PrevPiece = dyn_cast<PathDiagnosticControlFlowPiece>(Val: Prev->get());
1497
1498 if (PrevPiece) {
1499 if (const Stmt *PrevSrc =
1500 PrevPiece->getStartLocation().getStmtOrNull()) {
1501 const Stmt *PrevSrcParent = getStmtParent(S: PrevSrc, PM);
1502 if (PrevSrcParent ==
1503 getStmtParent(S: DstContext.getStmtOrNull(), PM)) {
1504 PrevPiece->setEndLocation(DstContext);
1505 break;
1506 }
1507 }
1508 }
1509 }
1510
1511 // Otherwise, split the current edge into a context edge and a
1512 // subexpression edge. Note that the context statement may itself have
1513 // context.
1514 auto P =
1515 std::make_shared<PathDiagnosticControlFlowPiece>(args&: SrcLoc, args&: DstContext);
1516 Piece = P.get();
1517 I = pieces.insert(position: I, x: std::move(P));
1518 }
1519 }
1520}
1521
1522/// Move edges from a branch condition to a branch target
1523/// when the condition is simple.
1524///
1525/// This restructures some of the work of addContextEdges. That function
1526/// creates edges this may destroy, but they work together to create a more
1527/// aesthetically set of edges around branches. After the call to
1528/// addContextEdges, we may have (1) an edge to the branch, (2) an edge from
1529/// the branch to the branch condition, and (3) an edge from the branch
1530/// condition to the branch target. We keep (1), but may wish to remove (2)
1531/// and move the source of (3) to the branch if the branch condition is simple.
1532static void simplifySimpleBranches(PathPieces &pieces) {
1533 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) {
1534 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1535
1536 if (!PieceI)
1537 continue;
1538
1539 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1540 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1541
1542 if (!s1Start || !s1End)
1543 continue;
1544
1545 PathPieces::iterator NextI = I; ++NextI;
1546 if (NextI == E)
1547 break;
1548
1549 PathDiagnosticControlFlowPiece *PieceNextI = nullptr;
1550
1551 while (true) {
1552 if (NextI == E)
1553 break;
1554
1555 const auto *EV = dyn_cast<PathDiagnosticEventPiece>(Val: NextI->get());
1556 if (EV) {
1557 StringRef S = EV->getString();
1558 if (S == StrEnteringLoop || S == StrLoopBodyZero ||
1559 S == StrLoopCollectionEmpty || S == StrLoopRangeEmpty) {
1560 ++NextI;
1561 continue;
1562 }
1563 break;
1564 }
1565
1566 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1567 break;
1568 }
1569
1570 if (!PieceNextI)
1571 continue;
1572
1573 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1574 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1575
1576 if (!s2Start || !s2End || s1End != s2Start)
1577 continue;
1578
1579 // We only perform this transformation for specific branch kinds.
1580 // We don't want to do this for do..while, for example.
1581 if (!isa<ForStmt, WhileStmt, IfStmt, ObjCForCollectionStmt,
1582 CXXForRangeStmt>(Val: s1Start))
1583 continue;
1584
1585 // Is s1End the branch condition?
1586 if (!isConditionForTerminator(S: s1Start, Cond: s1End))
1587 continue;
1588
1589 // Perform the hoisting by eliminating (2) and changing the start
1590 // location of (3).
1591 PieceNextI->setStartLocation(PieceI->getStartLocation());
1592 I = pieces.erase(position: I);
1593 }
1594}
1595
1596/// Returns the number of bytes in the given (character-based) SourceRange.
1597///
1598/// If the locations in the range are not on the same line, returns
1599/// std::nullopt.
1600///
1601/// Note that this does not do a precise user-visible character or column count.
1602static std::optional<size_t> getLengthOnSingleLine(const SourceManager &SM,
1603 SourceRange Range) {
1604 SourceRange ExpansionRange(SM.getExpansionLoc(Loc: Range.getBegin()),
1605 SM.getExpansionRange(Loc: Range.getEnd()).getEnd());
1606
1607 FileID FID = SM.getFileID(SpellingLoc: ExpansionRange.getBegin());
1608 if (FID != SM.getFileID(SpellingLoc: ExpansionRange.getEnd()))
1609 return std::nullopt;
1610
1611 std::optional<MemoryBufferRef> Buffer = SM.getBufferOrNone(FID);
1612 if (!Buffer)
1613 return std::nullopt;
1614
1615 unsigned BeginOffset = SM.getFileOffset(SpellingLoc: ExpansionRange.getBegin());
1616 unsigned EndOffset = SM.getFileOffset(SpellingLoc: ExpansionRange.getEnd());
1617 StringRef Snippet = Buffer->getBuffer().slice(Start: BeginOffset, End: EndOffset);
1618
1619 // We're searching the raw bytes of the buffer here, which might include
1620 // escaped newlines and such. That's okay; we're trying to decide whether the
1621 // SourceRange is covering a large or small amount of space in the user's
1622 // editor.
1623 if (Snippet.find_first_of(Chars: "\r\n") != StringRef::npos)
1624 return std::nullopt;
1625
1626 // This isn't Unicode-aware, but it doesn't need to be.
1627 return Snippet.size();
1628}
1629
1630/// \sa getLengthOnSingleLine(SourceManager, SourceRange)
1631static std::optional<size_t> getLengthOnSingleLine(const SourceManager &SM,
1632 const Stmt *S) {
1633 return getLengthOnSingleLine(SM, Range: S->getSourceRange());
1634}
1635
1636/// Eliminate two-edge cycles created by addContextEdges().
1637///
1638/// Once all the context edges are in place, there are plenty of cases where
1639/// there's a single edge from a top-level statement to a subexpression,
1640/// followed by a single path note, and then a reverse edge to get back out to
1641/// the top level. If the statement is simple enough, the subexpression edges
1642/// just add noise and make it harder to understand what's going on.
1643///
1644/// This function only removes edges in pairs, because removing only one edge
1645/// might leave other edges dangling.
1646///
1647/// This will not remove edges in more complicated situations:
1648/// - if there is more than one "hop" leading to or from a subexpression.
1649/// - if there is an inlined call between the edges instead of a single event.
1650/// - if the whole statement is large enough that having subexpression arrows
1651/// might be helpful.
1652static void removeContextCycles(PathPieces &Path, const SourceManager &SM) {
1653 for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) {
1654 // Pattern match the current piece and its successor.
1655 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1656
1657 if (!PieceI) {
1658 ++I;
1659 continue;
1660 }
1661
1662 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1663 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1664
1665 PathPieces::iterator NextI = I; ++NextI;
1666 if (NextI == E)
1667 break;
1668
1669 const auto *PieceNextI =
1670 dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1671
1672 if (!PieceNextI) {
1673 if (isa<PathDiagnosticEventPiece>(Val: NextI->get())) {
1674 ++NextI;
1675 if (NextI == E)
1676 break;
1677 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1678 }
1679
1680 if (!PieceNextI) {
1681 ++I;
1682 continue;
1683 }
1684 }
1685
1686 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1687 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1688
1689 if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) {
1690 const size_t MAX_SHORT_LINE_LENGTH = 80;
1691 std::optional<size_t> s1Length = getLengthOnSingleLine(SM, S: s1Start);
1692 if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) {
1693 std::optional<size_t> s2Length = getLengthOnSingleLine(SM, S: s2Start);
1694 if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) {
1695 Path.erase(position: I);
1696 I = Path.erase(position: NextI);
1697 continue;
1698 }
1699 }
1700 }
1701
1702 ++I;
1703 }
1704}
1705
1706/// Return true if X is contained by Y.
1707static bool lexicalContains(const ParentMap &PM, const Stmt *X, const Stmt *Y) {
1708 while (X) {
1709 if (X == Y)
1710 return true;
1711 X = PM.getParent(S: X);
1712 }
1713 return false;
1714}
1715
1716// Remove short edges on the same line less than 3 columns in difference.
1717static void removePunyEdges(PathPieces &path, const SourceManager &SM,
1718 const ParentMap &PM) {
1719 bool erased = false;
1720
1721 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E;
1722 erased ? I : ++I) {
1723 erased = false;
1724
1725 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1726
1727 if (!PieceI)
1728 continue;
1729
1730 const Stmt *start = PieceI->getStartLocation().getStmtOrNull();
1731 const Stmt *end = PieceI->getEndLocation().getStmtOrNull();
1732
1733 if (!start || !end)
1734 continue;
1735
1736 const Stmt *endParent = PM.getParent(S: end);
1737 if (!endParent)
1738 continue;
1739
1740 if (isConditionForTerminator(S: end, Cond: endParent))
1741 continue;
1742
1743 SourceLocation FirstLoc = start->getBeginLoc();
1744 SourceLocation SecondLoc = end->getBeginLoc();
1745
1746 if (!SM.isWrittenInSameFile(Loc1: FirstLoc, Loc2: SecondLoc))
1747 continue;
1748 if (SM.isBeforeInTranslationUnit(LHS: SecondLoc, RHS: FirstLoc))
1749 std::swap(a&: SecondLoc, b&: FirstLoc);
1750
1751 SourceRange EdgeRange(FirstLoc, SecondLoc);
1752 std::optional<size_t> ByteWidth = getLengthOnSingleLine(SM, Range: EdgeRange);
1753
1754 // If the statements are on different lines, continue.
1755 if (!ByteWidth)
1756 continue;
1757
1758 const size_t MAX_PUNY_EDGE_LENGTH = 2;
1759 if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) {
1760 // FIXME: There are enough /bytes/ between the endpoints of the edge, but
1761 // there might not be enough /columns/. A proper user-visible column count
1762 // is probably too expensive, though.
1763 I = path.erase(position: I);
1764 erased = true;
1765 continue;
1766 }
1767 }
1768}
1769
1770static void removeIdenticalEvents(PathPieces &path) {
1771 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) {
1772 const auto *PieceI = dyn_cast<PathDiagnosticEventPiece>(Val: I->get());
1773
1774 if (!PieceI)
1775 continue;
1776
1777 PathPieces::iterator NextI = I; ++NextI;
1778 if (NextI == E)
1779 return;
1780
1781 const auto *PieceNextI = dyn_cast<PathDiagnosticEventPiece>(Val: NextI->get());
1782
1783 if (!PieceNextI)
1784 continue;
1785
1786 // Erase the second piece if it has the same exact message text.
1787 if (PieceI->getString() == PieceNextI->getString()) {
1788 path.erase(position: NextI);
1789 }
1790 }
1791}
1792
1793static bool optimizeEdges(const PathDiagnosticConstruct &C, PathPieces &path,
1794 OptimizedCallsSet &OCS) {
1795 bool hasChanges = false;
1796 const LocationContext *LC = C.getLocationContextFor(Path: &path);
1797 assert(LC);
1798 const ParentMap &PM = LC->getParentMap();
1799 const SourceManager &SM = C.getSourceManager();
1800
1801 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
1802 // Optimize subpaths.
1803 if (auto *CallI = dyn_cast<PathDiagnosticCallPiece>(Val: I->get())) {
1804 // Record the fact that a call has been optimized so we only do the
1805 // effort once.
1806 if (!OCS.count(V: CallI)) {
1807 while (optimizeEdges(C, path&: CallI->path, OCS)) {
1808 }
1809 OCS.insert(V: CallI);
1810 }
1811 ++I;
1812 continue;
1813 }
1814
1815 // Pattern match the current piece and its successor.
1816 auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: I->get());
1817
1818 if (!PieceI) {
1819 ++I;
1820 continue;
1821 }
1822
1823 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1824 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1825 const Stmt *level1 = getStmtParent(S: s1Start, PM);
1826 const Stmt *level2 = getStmtParent(S: s1End, PM);
1827
1828 PathPieces::iterator NextI = I; ++NextI;
1829 if (NextI == E)
1830 break;
1831
1832 const auto *PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(Val: NextI->get());
1833
1834 if (!PieceNextI) {
1835 ++I;
1836 continue;
1837 }
1838
1839 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1840 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1841 const Stmt *level3 = getStmtParent(S: s2Start, PM);
1842 const Stmt *level4 = getStmtParent(S: s2End, PM);
1843
1844 // Rule I.
1845 //
1846 // If we have two consecutive control edges whose end/begin locations
1847 // are at the same level (e.g. statements or top-level expressions within
1848 // a compound statement, or siblings share a single ancestor expression),
1849 // then merge them if they have no interesting intermediate event.
1850 //
1851 // For example:
1852 //
1853 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common
1854 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements.
1855 //
1856 // NOTE: this will be limited later in cases where we add barriers
1857 // to prevent this optimization.
1858 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) {
1859 PieceI->setEndLocation(PieceNextI->getEndLocation());
1860 path.erase(position: NextI);
1861 hasChanges = true;
1862 continue;
1863 }
1864
1865 // Rule II.
1866 //
1867 // Eliminate edges between subexpressions and parent expressions
1868 // when the subexpression is consumed.
1869 //
1870 // NOTE: this will be limited later in cases where we add barriers
1871 // to prevent this optimization.
1872 if (s1End && s1End == s2Start && level2) {
1873 bool removeEdge = false;
1874 // Remove edges into the increment or initialization of a
1875 // loop that have no interleaving event. This means that
1876 // they aren't interesting.
1877 if (isIncrementOrInitInForLoop(S: s1End, FL: level2))
1878 removeEdge = true;
1879 // Next only consider edges that are not anchored on
1880 // the condition of a terminator. This are intermediate edges
1881 // that we might want to trim.
1882 else if (!isConditionForTerminator(S: level2, Cond: s1End)) {
1883 // Trim edges on expressions that are consumed by
1884 // the parent expression.
1885 if (isa<Expr>(Val: s1End) && PM.isConsumedExpr(E: cast<Expr>(Val: s1End))) {
1886 removeEdge = true;
1887 }
1888 // Trim edges where a lexical containment doesn't exist.
1889 // For example:
1890 //
1891 // X -> Y -> Z
1892 //
1893 // If 'Z' lexically contains Y (it is an ancestor) and
1894 // 'X' does not lexically contain Y (it is a descendant OR
1895 // it has no lexical relationship at all) then trim.
1896 //
1897 // This can eliminate edges where we dive into a subexpression
1898 // and then pop back out, etc.
1899 else if (s1Start && s2End &&
1900 lexicalContains(PM, X: s2Start, Y: s2End) &&
1901 !lexicalContains(PM, X: s1End, Y: s1Start)) {
1902 removeEdge = true;
1903 }
1904 // Trim edges from a subexpression back to the top level if the
1905 // subexpression is on a different line.
1906 //
1907 // A.1 -> A -> B
1908 // becomes
1909 // A.1 -> B
1910 //
1911 // These edges just look ugly and don't usually add anything.
1912 else if (s1Start && s2End &&
1913 lexicalContains(PM, X: s1Start, Y: s1End)) {
1914 SourceRange EdgeRange(PieceI->getEndLocation().asLocation(),
1915 PieceI->getStartLocation().asLocation());
1916 if (!getLengthOnSingleLine(SM, Range: EdgeRange))
1917 removeEdge = true;
1918 }
1919 }
1920
1921 if (removeEdge) {
1922 PieceI->setEndLocation(PieceNextI->getEndLocation());
1923 path.erase(position: NextI);
1924 hasChanges = true;
1925 continue;
1926 }
1927 }
1928
1929 // Optimize edges for ObjC fast-enumeration loops.
1930 //
1931 // (X -> collection) -> (collection -> element)
1932 //
1933 // becomes:
1934 //
1935 // (X -> element)
1936 if (s1End == s2Start) {
1937 const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(Val: level3);
1938 if (FS && FS->getCollection()->IgnoreParens() == s2Start &&
1939 s2End == FS->getElement()) {
1940 PieceI->setEndLocation(PieceNextI->getEndLocation());
1941 path.erase(position: NextI);
1942 hasChanges = true;
1943 continue;
1944 }
1945 }
1946
1947 // No changes at this index? Move to the next one.
1948 ++I;
1949 }
1950
1951 if (!hasChanges) {
1952 // Adjust edges into subexpressions to make them more uniform
1953 // and aesthetically pleasing.
1954 addContextEdges(pieces&: path, LC);
1955 // Remove "cyclical" edges that include one or more context edges.
1956 removeContextCycles(Path&: path, SM);
1957 // Hoist edges originating from branch conditions to branches
1958 // for simple branches.
1959 simplifySimpleBranches(pieces&: path);
1960 // Remove any puny edges left over after primary optimization pass.
1961 removePunyEdges(path, SM, PM);
1962 // Remove identical events.
1963 removeIdenticalEvents(path);
1964 }
1965
1966 return hasChanges;
1967}
1968
1969/// Drop the very first edge in a path, which should be a function entry edge.
1970///
1971/// If the first edge is not a function entry edge (say, because the first
1972/// statement had an invalid source location), this function does nothing.
1973// FIXME: We should just generate invalid edges anyway and have the optimizer
1974// deal with them.
1975static void dropFunctionEntryEdge(const PathDiagnosticConstruct &C,
1976 PathPieces &Path) {
1977 const auto *FirstEdge =
1978 dyn_cast<PathDiagnosticControlFlowPiece>(Val: Path.front().get());
1979 if (!FirstEdge)
1980 return;
1981
1982 const Decl *D = C.getLocationContextFor(Path: &Path)->getDecl();
1983 PathDiagnosticLocation EntryLoc =
1984 PathDiagnosticLocation::createBegin(D, SM: C.getSourceManager());
1985 if (FirstEdge->getStartLocation() != EntryLoc)
1986 return;
1987
1988 Path.pop_front();
1989}
1990
1991/// Populate executes lines with lines containing at least one diagnostics.
1992static void updateExecutedLinesWithDiagnosticPieces(PathDiagnostic &PD) {
1993
1994 PathPieces path = PD.path.flatten(/*ShouldFlattenMacros=*/true);
1995 FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines();
1996
1997 for (const auto &P : path) {
1998 FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc();
1999 FileID FID = Loc.getFileID();
2000 unsigned LineNo = Loc.getLineNumber();
2001 assert(FID.isValid());
2002 ExecutedLines[FID].insert(x: LineNo);
2003 }
2004}
2005
2006PathDiagnosticConstruct::PathDiagnosticConstruct(
2007 const PathDiagnosticConsumer *PDC, const ExplodedNode *ErrorNode,
2008 const PathSensitiveBugReport *R, const Decl *AnalysisEntryPoint)
2009 : Consumer(PDC), CurrentNode(ErrorNode),
2010 SM(CurrentNode->getCodeDecl().getASTContext().getSourceManager()),
2011 PD(generateEmptyDiagnosticForReport(R, SM: getSourceManager(),
2012 AnalysisEntryPoint)) {
2013 LCM[&PD->getActivePath()] = ErrorNode->getLocationContext();
2014}
2015
2016PathDiagnosticBuilder::PathDiagnosticBuilder(
2017 BugReporterContext BRC, std::unique_ptr<ExplodedGraph> BugPath,
2018 PathSensitiveBugReport *r, const ExplodedNode *ErrorNode,
2019 std::unique_ptr<VisitorsDiagnosticsTy> VisitorsDiagnostics)
2020 : BugReporterContext(BRC), BugPath(std::move(BugPath)), R(r),
2021 ErrorNode(ErrorNode),
2022 VisitorsDiagnostics(std::move(VisitorsDiagnostics)) {}
2023
2024std::unique_ptr<PathDiagnostic>
2025PathDiagnosticBuilder::generate(const PathDiagnosticConsumer *PDC) const {
2026 const Decl *EntryPoint = getBugReporter().getAnalysisEntryPoint();
2027 PathDiagnosticConstruct Construct(PDC, ErrorNode, R, EntryPoint);
2028
2029 const SourceManager &SM = getSourceManager();
2030 const AnalyzerOptions &Opts = getAnalyzerOptions();
2031
2032 if (!PDC->shouldGenerateDiagnostics())
2033 return generateEmptyDiagnosticForReport(R, SM: getSourceManager(), AnalysisEntryPoint: EntryPoint);
2034
2035 // Construct the final (warning) event for the bug report.
2036 auto EndNotes = VisitorsDiagnostics->find(Val: ErrorNode);
2037 PathDiagnosticPieceRef LastPiece;
2038 if (EndNotes != VisitorsDiagnostics->end()) {
2039 assert(!EndNotes->second.empty());
2040 LastPiece = EndNotes->second[0];
2041 } else {
2042 LastPiece = BugReporterVisitor::getDefaultEndPath(BRC: *this, N: ErrorNode,
2043 BR: *getBugReport());
2044 }
2045 Construct.PD->setEndOfPath(LastPiece);
2046
2047 PathDiagnosticLocation PrevLoc = Construct.PD->getLocation();
2048 // From the error node to the root, ascend the bug path and construct the bug
2049 // report.
2050 while (Construct.ascendToPrevNode()) {
2051 generatePathDiagnosticsForNode(C&: Construct, PrevLoc);
2052
2053 auto VisitorNotes = VisitorsDiagnostics->find(Val: Construct.getCurrentNode());
2054 if (VisitorNotes == VisitorsDiagnostics->end())
2055 continue;
2056
2057 // This is a workaround due to inability to put shared PathDiagnosticPiece
2058 // into a FoldingSet.
2059 std::set<llvm::FoldingSetNodeID> DeduplicationSet;
2060
2061 // Add pieces from custom visitors.
2062 for (const PathDiagnosticPieceRef &Note : VisitorNotes->second) {
2063 llvm::FoldingSetNodeID ID;
2064 Note->Profile(ID);
2065 if (!DeduplicationSet.insert(x: ID).second)
2066 continue;
2067
2068 if (PDC->shouldAddPathEdges())
2069 addEdgeToPath(path&: Construct.getActivePath(), PrevLoc, NewLoc: Note->getLocation());
2070 updateStackPiecesWithMessage(P: Note, CallStack: Construct.CallStack);
2071 Construct.getActivePath().push_front(x: Note);
2072 }
2073 }
2074
2075 if (PDC->shouldAddPathEdges()) {
2076 // Add an edge to the start of the function.
2077 // We'll prune it out later, but it helps make diagnostics more uniform.
2078 const StackFrameContext *CalleeLC =
2079 Construct.getLocationContextForActivePath()->getStackFrame();
2080 const Decl *D = CalleeLC->getDecl();
2081 addEdgeToPath(path&: Construct.getActivePath(), PrevLoc,
2082 NewLoc: PathDiagnosticLocation::createBegin(D, SM));
2083 }
2084
2085
2086 // Finally, prune the diagnostic path of uninteresting stuff.
2087 if (!Construct.PD->path.empty()) {
2088 if (R->shouldPrunePath() && Opts.ShouldPrunePaths) {
2089 bool stillHasNotes =
2090 removeUnneededCalls(C: Construct, pieces&: Construct.getMutablePieces(), R);
2091 assert(stillHasNotes);
2092 (void)stillHasNotes;
2093 }
2094
2095 // Remove pop-up notes if needed.
2096 if (!Opts.ShouldAddPopUpNotes)
2097 removePopUpNotes(Path&: Construct.getMutablePieces());
2098
2099 // Redirect all call pieces to have valid locations.
2100 adjustCallLocations(Pieces&: Construct.getMutablePieces());
2101 removePiecesWithInvalidLocations(Pieces&: Construct.getMutablePieces());
2102
2103 if (PDC->shouldAddPathEdges()) {
2104
2105 // Reduce the number of edges from a very conservative set
2106 // to an aesthetically pleasing subset that conveys the
2107 // necessary information.
2108 OptimizedCallsSet OCS;
2109 while (optimizeEdges(C: Construct, path&: Construct.getMutablePieces(), OCS)) {
2110 }
2111
2112 // Drop the very first function-entry edge. It's not really necessary
2113 // for top-level functions.
2114 dropFunctionEntryEdge(C: Construct, Path&: Construct.getMutablePieces());
2115 }
2116
2117 // Remove messages that are basically the same, and edges that may not
2118 // make sense.
2119 // We have to do this after edge optimization in the Extensive mode.
2120 removeRedundantMsgs(path&: Construct.getMutablePieces());
2121 removeEdgesToDefaultInitializers(Pieces&: Construct.getMutablePieces());
2122 }
2123
2124 if (Opts.ShouldDisplayMacroExpansions)
2125 CompactMacroExpandedPieces(path&: Construct.getMutablePieces(), SM);
2126
2127 return std::move(Construct.PD);
2128}
2129
2130//===----------------------------------------------------------------------===//
2131// Methods for BugType and subclasses.
2132//===----------------------------------------------------------------------===//
2133
2134void BugType::anchor() {}
2135
2136//===----------------------------------------------------------------------===//
2137// Methods for BugReport and subclasses.
2138//===----------------------------------------------------------------------===//
2139
2140LLVM_ATTRIBUTE_USED static bool
2141isDependency(const CheckerRegistryData &Registry, StringRef CheckerName) {
2142 for (const std::pair<StringRef, StringRef> &Pair : Registry.Dependencies) {
2143 if (Pair.second == CheckerName)
2144 return true;
2145 }
2146 return false;
2147}
2148
2149LLVM_ATTRIBUTE_USED static bool isHidden(const CheckerRegistryData &Registry,
2150 StringRef CheckerName) {
2151 for (const CheckerInfo &Checker : Registry.Checkers) {
2152 if (Checker.FullName == CheckerName)
2153 return Checker.IsHidden;
2154 }
2155 llvm_unreachable(
2156 "Checker name not found in CheckerRegistry -- did you retrieve it "
2157 "correctly from CheckerManager::getCurrentCheckerName?");
2158}
2159
2160PathSensitiveBugReport::PathSensitiveBugReport(
2161 const BugType &bt, StringRef shortDesc, StringRef desc,
2162 const ExplodedNode *errorNode, PathDiagnosticLocation LocationToUnique,
2163 const Decl *DeclToUnique)
2164 : BugReport(Kind::PathSensitive, bt, shortDesc, desc), ErrorNode(errorNode),
2165 ErrorNodeRange(getStmt() ? getStmt()->getSourceRange() : SourceRange()),
2166 UniqueingLocation(LocationToUnique), UniqueingDecl(DeclToUnique) {
2167 assert(ErrorNode && "The error node must be non-null!");
2168 assert(!isDependency(ErrorNode->getState()
2169 ->getAnalysisManager()
2170 .getCheckerManager()
2171 ->getCheckerRegistryData(),
2172 bt.getCheckerName()) &&
2173 "Some checkers depend on this one! We don't allow dependency "
2174 "checkers to emit warnings, because checkers should depend on "
2175 "*modeling*, not *diagnostics*.");
2176
2177 assert((bt.getCheckerName().starts_with("debug") ||
2178 !isHidden(ErrorNode->getState()
2179 ->getAnalysisManager()
2180 .getCheckerManager()
2181 ->getCheckerRegistryData(),
2182 bt.getCheckerName())) &&
2183 "Hidden checkers musn't emit diagnostics as they are by definition "
2184 "non-user facing!");
2185}
2186
2187void PathSensitiveBugReport::addVisitor(
2188 std::unique_ptr<BugReporterVisitor> visitor) {
2189 if (!visitor)
2190 return;
2191
2192 llvm::FoldingSetNodeID ID;
2193 visitor->Profile(ID);
2194
2195 void *InsertPos = nullptr;
2196 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
2197 return;
2198 }
2199
2200 Callbacks.push_back(Elt: std::move(visitor));
2201}
2202
2203void PathSensitiveBugReport::clearVisitors() {
2204 Callbacks.clear();
2205}
2206
2207const Decl *PathSensitiveBugReport::getDeclWithIssue() const {
2208 const ExplodedNode *N = getErrorNode();
2209 if (!N)
2210 return nullptr;
2211
2212 const LocationContext *LC = N->getLocationContext();
2213 return LC->getStackFrame()->getDecl();
2214}
2215
2216void BasicBugReport::Profile(llvm::FoldingSetNodeID& hash) const {
2217 hash.AddInteger(I: static_cast<int>(getKind()));
2218 hash.AddPointer(Ptr: &BT);
2219 hash.AddString(String: getShortDescription());
2220 assert(Location.isValid());
2221 Location.Profile(ID&: hash);
2222
2223 for (SourceRange range : Ranges) {
2224 if (!range.isValid())
2225 continue;
2226 hash.Add(x: range.getBegin());
2227 hash.Add(x: range.getEnd());
2228 }
2229}
2230
2231void PathSensitiveBugReport::Profile(llvm::FoldingSetNodeID &hash) const {
2232 hash.AddInteger(I: static_cast<int>(getKind()));
2233 hash.AddPointer(Ptr: &BT);
2234 hash.AddString(String: getShortDescription());
2235 PathDiagnosticLocation UL = getUniqueingLocation();
2236 if (UL.isValid()) {
2237 UL.Profile(ID&: hash);
2238 } else {
2239 // TODO: The statement may be null if the report was emitted before any
2240 // statements were executed. In particular, some checkers by design
2241 // occasionally emit their reports in empty functions (that have no
2242 // statements in their body). Do we profile correctly in this case?
2243 hash.AddPointer(Ptr: ErrorNode->getCurrentOrPreviousStmtForDiagnostics());
2244 }
2245
2246 for (SourceRange range : Ranges) {
2247 if (!range.isValid())
2248 continue;
2249 hash.Add(x: range.getBegin());
2250 hash.Add(x: range.getEnd());
2251 }
2252}
2253
2254template <class T>
2255static void insertToInterestingnessMap(
2256 llvm::DenseMap<T, bugreporter::TrackingKind> &InterestingnessMap, T Val,
2257 bugreporter::TrackingKind TKind) {
2258 auto Result = InterestingnessMap.insert({Val, TKind});
2259
2260 if (Result.second)
2261 return;
2262
2263 // Even if this symbol/region was already marked as interesting as a
2264 // condition, if we later mark it as interesting again but with
2265 // thorough tracking, overwrite it. Entities marked with thorough
2266 // interestiness are the most important (or most interesting, if you will),
2267 // and we wouldn't like to downplay their importance.
2268
2269 switch (TKind) {
2270 case bugreporter::TrackingKind::Thorough:
2271 Result.first->getSecond() = bugreporter::TrackingKind::Thorough;
2272 return;
2273 case bugreporter::TrackingKind::Condition:
2274 return;
2275 }
2276
2277 llvm_unreachable(
2278 "BugReport::markInteresting currently can only handle 2 different "
2279 "tracking kinds! Please define what tracking kind should this entitiy"
2280 "have, if it was already marked as interesting with a different kind!");
2281}
2282
2283void PathSensitiveBugReport::markInteresting(SymbolRef sym,
2284 bugreporter::TrackingKind TKind) {
2285 if (!sym)
2286 return;
2287
2288 insertToInterestingnessMap(InterestingnessMap&: InterestingSymbols, Val: sym, TKind);
2289
2290 // FIXME: No tests exist for this code and it is questionable:
2291 // How to handle multiple metadata for the same region?
2292 if (const auto *meta = dyn_cast<SymbolMetadata>(Val: sym))
2293 markInteresting(R: meta->getRegion(), TKind);
2294}
2295
2296void PathSensitiveBugReport::markNotInteresting(SymbolRef sym) {
2297 if (!sym)
2298 return;
2299 InterestingSymbols.erase(Val: sym);
2300
2301 // The metadata part of markInteresting is not reversed here.
2302 // Just making the same region not interesting is incorrect
2303 // in specific cases.
2304 if (const auto *meta = dyn_cast<SymbolMetadata>(Val: sym))
2305 markNotInteresting(R: meta->getRegion());
2306}
2307
2308void PathSensitiveBugReport::markInteresting(const MemRegion *R,
2309 bugreporter::TrackingKind TKind) {
2310 if (!R)
2311 return;
2312
2313 R = R->getBaseRegion();
2314 insertToInterestingnessMap(InterestingnessMap&: InterestingRegions, Val: R, TKind);
2315
2316 if (const auto *SR = dyn_cast<SymbolicRegion>(Val: R))
2317 markInteresting(sym: SR->getSymbol(), TKind);
2318}
2319
2320void PathSensitiveBugReport::markNotInteresting(const MemRegion *R) {
2321 if (!R)
2322 return;
2323
2324 R = R->getBaseRegion();
2325 InterestingRegions.erase(Val: R);
2326
2327 if (const auto *SR = dyn_cast<SymbolicRegion>(Val: R))
2328 markNotInteresting(sym: SR->getSymbol());
2329}
2330
2331void PathSensitiveBugReport::markInteresting(SVal V,
2332 bugreporter::TrackingKind TKind) {
2333 markInteresting(R: V.getAsRegion(), TKind);
2334 markInteresting(sym: V.getAsSymbol(), TKind);
2335}
2336
2337void PathSensitiveBugReport::markInteresting(const LocationContext *LC) {
2338 if (!LC)
2339 return;
2340 InterestingLocationContexts.insert(Ptr: LC);
2341}
2342
2343std::optional<bugreporter::TrackingKind>
2344PathSensitiveBugReport::getInterestingnessKind(SVal V) const {
2345 auto RKind = getInterestingnessKind(R: V.getAsRegion());
2346 auto SKind = getInterestingnessKind(sym: V.getAsSymbol());
2347 if (!RKind)
2348 return SKind;
2349 if (!SKind)
2350 return RKind;
2351
2352 // If either is marked with throrough tracking, return that, we wouldn't like
2353 // to downplay a note's importance by 'only' mentioning it as a condition.
2354 switch(*RKind) {
2355 case bugreporter::TrackingKind::Thorough:
2356 return RKind;
2357 case bugreporter::TrackingKind::Condition:
2358 return SKind;
2359 }
2360
2361 llvm_unreachable(
2362 "BugReport::getInterestingnessKind currently can only handle 2 different "
2363 "tracking kinds! Please define what tracking kind should we return here "
2364 "when the kind of getAsRegion() and getAsSymbol() is different!");
2365 return std::nullopt;
2366}
2367
2368std::optional<bugreporter::TrackingKind>
2369PathSensitiveBugReport::getInterestingnessKind(SymbolRef sym) const {
2370 if (!sym)
2371 return std::nullopt;
2372 // We don't currently consider metadata symbols to be interesting
2373 // even if we know their region is interesting. Is that correct behavior?
2374 auto It = InterestingSymbols.find(Val: sym);
2375 if (It == InterestingSymbols.end())
2376 return std::nullopt;
2377 return It->getSecond();
2378}
2379
2380std::optional<bugreporter::TrackingKind>
2381PathSensitiveBugReport::getInterestingnessKind(const MemRegion *R) const {
2382 if (!R)
2383 return std::nullopt;
2384
2385 R = R->getBaseRegion();
2386 auto It = InterestingRegions.find(Val: R);
2387 if (It != InterestingRegions.end())
2388 return It->getSecond();
2389
2390 if (const auto *SR = dyn_cast<SymbolicRegion>(Val: R))
2391 return getInterestingnessKind(sym: SR->getSymbol());
2392 return std::nullopt;
2393}
2394
2395bool PathSensitiveBugReport::isInteresting(SVal V) const {
2396 return getInterestingnessKind(V).has_value();
2397}
2398
2399bool PathSensitiveBugReport::isInteresting(SymbolRef sym) const {
2400 return getInterestingnessKind(sym).has_value();
2401}
2402
2403bool PathSensitiveBugReport::isInteresting(const MemRegion *R) const {
2404 return getInterestingnessKind(R).has_value();
2405}
2406
2407bool PathSensitiveBugReport::isInteresting(const LocationContext *LC) const {
2408 if (!LC)
2409 return false;
2410 return InterestingLocationContexts.count(Ptr: LC);
2411}
2412
2413const Stmt *PathSensitiveBugReport::getStmt() const {
2414 if (!ErrorNode)
2415 return nullptr;
2416
2417 ProgramPoint ProgP = ErrorNode->getLocation();
2418 const Stmt *S = nullptr;
2419
2420 if (std::optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) {
2421 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
2422 if (BE->getBlock() == &Exit)
2423 S = ErrorNode->getPreviousStmtForDiagnostics();
2424 }
2425 if (!S)
2426 S = ErrorNode->getStmtForDiagnostics();
2427
2428 return S;
2429}
2430
2431ArrayRef<SourceRange>
2432PathSensitiveBugReport::getRanges() const {
2433 // If no custom ranges, add the range of the statement corresponding to
2434 // the error node.
2435 if (Ranges.empty() && isa_and_nonnull<Expr>(Val: getStmt()))
2436 return ErrorNodeRange;
2437
2438 return Ranges;
2439}
2440
2441static bool exitingDestructor(const ExplodedNode *N) {
2442 // Need to loop here, as some times the Error node is already outside of the
2443 // destructor context, and the previous node is an edge that is also outside.
2444 while (N && !N->getLocation().getAs<StmtPoint>()) {
2445 N = N->getFirstPred();
2446 }
2447 return N && isa<CXXDestructorDecl>(Val: N->getLocationContext()->getDecl());
2448}
2449
2450static const Stmt *
2451findReasonableStmtCloseToFunctionExit(const ExplodedNode *N) {
2452 if (exitingDestructor(N)) {
2453 // If we are exiting a destructor call, it is more useful to point to
2454 // the next stmt which is usually the temporary declaration.
2455 if (const Stmt *S = N->getNextStmtForDiagnostics())
2456 return S;
2457 // If next stmt is not found, it is likely the end of a top-level
2458 // function analysis. find the last execution statement then.
2459 }
2460 return N->getPreviousStmtForDiagnostics();
2461}
2462
2463PathDiagnosticLocation
2464PathSensitiveBugReport::getLocation() const {
2465 assert(ErrorNode && "Cannot create a location with a null node.");
2466 const Stmt *S = ErrorNode->getStmtForDiagnostics();
2467 ProgramPoint P = ErrorNode->getLocation();
2468 const LocationContext *LC = P.getLocationContext();
2469 SourceManager &SM =
2470 ErrorNode->getState()->getStateManager().getContext().getSourceManager();
2471
2472 if (!S) {
2473 // If this is an implicit call, return the implicit call point location.
2474 if (std::optional<PreImplicitCall> PIE = P.getAs<PreImplicitCall>())
2475 return PathDiagnosticLocation(PIE->getLocation(), SM);
2476 if (auto FE = P.getAs<FunctionExitPoint>()) {
2477 if (const ReturnStmt *RS = FE->getStmt())
2478 return PathDiagnosticLocation::createBegin(S: RS, SM, LAC: LC);
2479
2480 S = findReasonableStmtCloseToFunctionExit(N: ErrorNode);
2481 }
2482 if (!S)
2483 S = ErrorNode->getNextStmtForDiagnostics();
2484 }
2485
2486 if (S) {
2487 // Attributed statements usually have corrupted begin locations,
2488 // it's OK to ignore attributes for our purposes and deal with
2489 // the actual annotated statement.
2490 if (const auto *AS = dyn_cast<AttributedStmt>(Val: S))
2491 S = AS->getSubStmt();
2492
2493 // For member expressions, return the location of the '.' or '->'.
2494 if (const auto *ME = dyn_cast<MemberExpr>(Val: S))
2495 return PathDiagnosticLocation::createMemberLoc(ME, SM);
2496
2497 // For binary operators, return the location of the operator.
2498 if (const auto *B = dyn_cast<BinaryOperator>(Val: S))
2499 return PathDiagnosticLocation::createOperatorLoc(BO: B, SM);
2500
2501 if (P.getAs<PostStmtPurgeDeadSymbols>())
2502 return PathDiagnosticLocation::createEnd(S, SM, LAC: LC);
2503
2504 if (S->getBeginLoc().isValid())
2505 return PathDiagnosticLocation(S, SM, LC);
2506
2507 return PathDiagnosticLocation(
2508 PathDiagnosticLocation::getValidSourceLocation(S, LAC: LC), SM);
2509 }
2510
2511 return PathDiagnosticLocation::createDeclEnd(LC: ErrorNode->getLocationContext(),
2512 SM);
2513}
2514
2515//===----------------------------------------------------------------------===//
2516// Methods for BugReporter and subclasses.
2517//===----------------------------------------------------------------------===//
2518
2519const ExplodedGraph &PathSensitiveBugReporter::getGraph() const {
2520 return Eng.getGraph();
2521}
2522
2523ProgramStateManager &PathSensitiveBugReporter::getStateManager() const {
2524 return Eng.getStateManager();
2525}
2526
2527BugReporter::BugReporter(BugReporterData &D)
2528 : D(D), UserSuppressions(D.getASTContext()) {}
2529
2530BugReporter::~BugReporter() {
2531 // Make sure reports are flushed.
2532 assert(StrBugTypes.empty() &&
2533 "Destroying BugReporter before diagnostics are emitted!");
2534
2535 // Free the bug reports we are tracking.
2536 for (const auto I : EQClassesVector)
2537 delete I;
2538}
2539
2540void BugReporter::FlushReports() {
2541 // We need to flush reports in deterministic order to ensure the order
2542 // of the reports is consistent between runs.
2543 for (const auto EQ : EQClassesVector)
2544 FlushReport(EQ&: *EQ);
2545
2546 // BugReporter owns and deletes only BugTypes created implicitly through
2547 // EmitBasicReport.
2548 // FIXME: There are leaks from checkers that assume that the BugTypes they
2549 // create will be destroyed by the BugReporter.
2550 StrBugTypes.clear();
2551}
2552
2553//===----------------------------------------------------------------------===//
2554// PathDiagnostics generation.
2555//===----------------------------------------------------------------------===//
2556
2557namespace {
2558
2559/// A wrapper around an ExplodedGraph that contains a single path from the root
2560/// to the error node.
2561class BugPathInfo {
2562public:
2563 std::unique_ptr<ExplodedGraph> BugPath;
2564 PathSensitiveBugReport *Report;
2565 const ExplodedNode *ErrorNode;
2566};
2567
2568/// A wrapper around an ExplodedGraph whose leafs are all error nodes. Can
2569/// conveniently retrieve bug paths from a single error node to the root.
2570class BugPathGetter {
2571 std::unique_ptr<ExplodedGraph> TrimmedGraph;
2572
2573 using PriorityMapTy = llvm::DenseMap<const ExplodedNode *, unsigned>;
2574
2575 /// Assign each node with its distance from the root.
2576 PriorityMapTy PriorityMap;
2577
2578 /// Since the getErrorNode() or BugReport refers to the original ExplodedGraph,
2579 /// we need to pair it to the error node of the constructed trimmed graph.
2580 using ReportNewNodePair =
2581 std::pair<PathSensitiveBugReport *, const ExplodedNode *>;
2582 SmallVector<ReportNewNodePair, 32> ReportNodes;
2583
2584 BugPathInfo CurrentBugPath;
2585
2586 /// A helper class for sorting ExplodedNodes by priority.
2587 template <bool Descending>
2588 class PriorityCompare {
2589 const PriorityMapTy &PriorityMap;
2590
2591 public:
2592 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {}
2593
2594 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const {
2595 PriorityMapTy::const_iterator LI = PriorityMap.find(Val: LHS);
2596 PriorityMapTy::const_iterator RI = PriorityMap.find(Val: RHS);
2597 PriorityMapTy::const_iterator E = PriorityMap.end();
2598
2599 if (LI == E)
2600 return Descending;
2601 if (RI == E)
2602 return !Descending;
2603
2604 return Descending ? LI->second > RI->second
2605 : LI->second < RI->second;
2606 }
2607
2608 bool operator()(const ReportNewNodePair &LHS,
2609 const ReportNewNodePair &RHS) const {
2610 return (*this)(LHS.second, RHS.second);
2611 }
2612 };
2613
2614public:
2615 BugPathGetter(const ExplodedGraph *OriginalGraph,
2616 ArrayRef<PathSensitiveBugReport *> &bugReports);
2617
2618 BugPathInfo *getNextBugPath();
2619};
2620
2621} // namespace
2622
2623BugPathGetter::BugPathGetter(const ExplodedGraph *OriginalGraph,
2624 ArrayRef<PathSensitiveBugReport *> &bugReports) {
2625 SmallVector<const ExplodedNode *, 32> Nodes;
2626 for (const auto I : bugReports) {
2627 assert(I->isValid() &&
2628 "We only allow BugReporterVisitors and BugReporter itself to "
2629 "invalidate reports!");
2630 Nodes.emplace_back(Args: I->getErrorNode());
2631 }
2632
2633 // The trimmed graph is created in the body of the constructor to ensure
2634 // that the DenseMaps have been initialized already.
2635 InterExplodedGraphMap ForwardMap;
2636 TrimmedGraph = OriginalGraph->trim(Nodes, ForwardMap: &ForwardMap);
2637
2638 // Find the (first) error node in the trimmed graph. We just need to consult
2639 // the node map which maps from nodes in the original graph to nodes
2640 // in the new graph.
2641 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes;
2642
2643 for (PathSensitiveBugReport *Report : bugReports) {
2644 const ExplodedNode *NewNode = ForwardMap.lookup(Val: Report->getErrorNode());
2645 assert(NewNode &&
2646 "Failed to construct a trimmed graph that contains this error "
2647 "node!");
2648 ReportNodes.emplace_back(Args&: Report, Args&: NewNode);
2649 RemainingNodes.insert(Ptr: NewNode);
2650 }
2651
2652 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph");
2653
2654 // Perform a forward BFS to find all the shortest paths.
2655 std::queue<const ExplodedNode *> WS;
2656
2657 WS.push(x: TrimmedGraph->getRoot());
2658 unsigned Priority = 0;
2659
2660 while (!WS.empty()) {
2661 const ExplodedNode *Node = WS.front();
2662 WS.pop();
2663
2664 PriorityMapTy::iterator PriorityEntry;
2665 bool IsNew;
2666 std::tie(args&: PriorityEntry, args&: IsNew) = PriorityMap.insert(KV: {Node, Priority});
2667 ++Priority;
2668
2669 if (!IsNew) {
2670 assert(PriorityEntry->second <= Priority);
2671 continue;
2672 }
2673
2674 if (RemainingNodes.erase(Ptr: Node))
2675 if (RemainingNodes.empty())
2676 break;
2677
2678 for (const ExplodedNode *Succ : Node->succs())
2679 WS.push(x: Succ);
2680 }
2681
2682 // Sort the error paths from longest to shortest.
2683 llvm::sort(C&: ReportNodes, Comp: PriorityCompare<true>(PriorityMap));
2684}
2685
2686BugPathInfo *BugPathGetter::getNextBugPath() {
2687 if (ReportNodes.empty())
2688 return nullptr;
2689
2690 const ExplodedNode *OrigN;
2691 std::tie(args&: CurrentBugPath.Report, args&: OrigN) = ReportNodes.pop_back_val();
2692 assert(PriorityMap.contains(OrigN) && "error node not accessible from root");
2693
2694 // Create a new graph with a single path. This is the graph that will be
2695 // returned to the caller.
2696 auto GNew = std::make_unique<ExplodedGraph>();
2697
2698 // Now walk from the error node up the BFS path, always taking the
2699 // predeccessor with the lowest number.
2700 ExplodedNode *Succ = nullptr;
2701 while (true) {
2702 // Create the equivalent node in the new graph with the same state
2703 // and location.
2704 ExplodedNode *NewN = GNew->createUncachedNode(
2705 L: OrigN->getLocation(), State: OrigN->getState(),
2706 Id: OrigN->getID(), IsSink: OrigN->isSink());
2707
2708 // Link up the new node with the previous node.
2709 if (Succ)
2710 Succ->addPredecessor(V: NewN, G&: *GNew);
2711 else
2712 CurrentBugPath.ErrorNode = NewN;
2713
2714 Succ = NewN;
2715
2716 // Are we at the final node?
2717 if (OrigN->pred_empty()) {
2718 assert(OrigN == TrimmedGraph->getRoot() &&
2719 "There should be only one root!");
2720 GNew->designateAsRoot(V: NewN);
2721 break;
2722 }
2723
2724 // Find the next predeccessor node. We choose the node that is marked
2725 // with the lowest BFS number.
2726 OrigN = *std::min_element(first: OrigN->pred_begin(), last: OrigN->pred_end(),
2727 comp: PriorityCompare<false>(PriorityMap));
2728 }
2729
2730 CurrentBugPath.BugPath = std::move(GNew);
2731
2732 return &CurrentBugPath;
2733}
2734
2735/// CompactMacroExpandedPieces - This function postprocesses a PathDiagnostic
2736/// object and collapses PathDiagosticPieces that are expanded by macros.
2737static void CompactMacroExpandedPieces(PathPieces &path,
2738 const SourceManager& SM) {
2739 using MacroStackTy = std::vector<
2740 std::pair<std::shared_ptr<PathDiagnosticMacroPiece>, SourceLocation>>;
2741
2742 using PiecesTy = std::vector<PathDiagnosticPieceRef>;
2743
2744 MacroStackTy MacroStack;
2745 PiecesTy Pieces;
2746
2747 for (PathPieces::const_iterator I = path.begin(), E = path.end();
2748 I != E; ++I) {
2749 const auto &piece = *I;
2750
2751 // Recursively compact calls.
2752 if (auto *call = dyn_cast<PathDiagnosticCallPiece>(Val: &*piece)) {
2753 CompactMacroExpandedPieces(path&: call->path, SM);
2754 }
2755
2756 // Get the location of the PathDiagnosticPiece.
2757 const FullSourceLoc Loc = piece->getLocation().asLocation();
2758
2759 // Determine the instantiation location, which is the location we group
2760 // related PathDiagnosticPieces.
2761 SourceLocation InstantiationLoc = Loc.isMacroID() ?
2762 SM.getExpansionLoc(Loc) :
2763 SourceLocation();
2764
2765 if (Loc.isFileID()) {
2766 MacroStack.clear();
2767 Pieces.push_back(x: piece);
2768 continue;
2769 }
2770
2771 assert(Loc.isMacroID());
2772
2773 // Is the PathDiagnosticPiece within the same macro group?
2774 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
2775 MacroStack.back().first->subPieces.push_back(x: piece);
2776 continue;
2777 }
2778
2779 // We aren't in the same group. Are we descending into a new macro
2780 // or are part of an old one?
2781 std::shared_ptr<PathDiagnosticMacroPiece> MacroGroup;
2782
2783 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
2784 SM.getExpansionLoc(Loc) :
2785 SourceLocation();
2786
2787 // Walk the entire macro stack.
2788 while (!MacroStack.empty()) {
2789 if (InstantiationLoc == MacroStack.back().second) {
2790 MacroGroup = MacroStack.back().first;
2791 break;
2792 }
2793
2794 if (ParentInstantiationLoc == MacroStack.back().second) {
2795 MacroGroup = MacroStack.back().first;
2796 break;
2797 }
2798
2799 MacroStack.pop_back();
2800 }
2801
2802 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) {
2803 // Create a new macro group and add it to the stack.
2804 auto NewGroup = std::make_shared<PathDiagnosticMacroPiece>(
2805 args: PathDiagnosticLocation::createSingleLocation(PDL: piece->getLocation()));
2806
2807 if (MacroGroup)
2808 MacroGroup->subPieces.push_back(x: NewGroup);
2809 else {
2810 assert(InstantiationLoc.isFileID());
2811 Pieces.push_back(x: NewGroup);
2812 }
2813
2814 MacroGroup = NewGroup;
2815 MacroStack.push_back(x: std::make_pair(x&: MacroGroup, y&: InstantiationLoc));
2816 }
2817
2818 // Finally, add the PathDiagnosticPiece to the group.
2819 MacroGroup->subPieces.push_back(x: piece);
2820 }
2821
2822 // Now take the pieces and construct a new PathDiagnostic.
2823 path.clear();
2824
2825 llvm::append_range(C&: path, R&: Pieces);
2826}
2827
2828/// Generate notes from all visitors.
2829/// Notes associated with @c ErrorNode are generated using
2830/// @c getEndPath, and the rest are generated with @c VisitNode.
2831static std::unique_ptr<VisitorsDiagnosticsTy>
2832generateVisitorsDiagnostics(PathSensitiveBugReport *R,
2833 const ExplodedNode *ErrorNode,
2834 BugReporterContext &BRC) {
2835 std::unique_ptr<VisitorsDiagnosticsTy> Notes =
2836 std::make_unique<VisitorsDiagnosticsTy>();
2837 PathSensitiveBugReport::VisitorList visitors;
2838
2839 // Run visitors on all nodes starting from the node *before* the last one.
2840 // The last node is reserved for notes generated with @c getEndPath.
2841 const ExplodedNode *NextNode = ErrorNode->getFirstPred();
2842 while (NextNode) {
2843
2844 // At each iteration, move all visitors from report to visitor list. This is
2845 // important, because the Profile() functions of the visitors make sure that
2846 // a visitor isn't added multiple times for the same node, but it's fine
2847 // to add the a visitor with Profile() for different nodes (e.g. tracking
2848 // a region at different points of the symbolic execution).
2849 for (std::unique_ptr<BugReporterVisitor> &Visitor : R->visitors())
2850 visitors.push_back(Elt: std::move(Visitor));
2851
2852 R->clearVisitors();
2853
2854 const ExplodedNode *Pred = NextNode->getFirstPred();
2855 if (!Pred) {
2856 PathDiagnosticPieceRef LastPiece;
2857 for (auto &V : visitors) {
2858 V->finalizeVisitor(BRC, EndPathNode: ErrorNode, BR&: *R);
2859
2860 if (auto Piece = V->getEndPath(BRC, N: ErrorNode, BR&: *R)) {
2861 assert(!LastPiece &&
2862 "There can only be one final piece in a diagnostic.");
2863 assert(Piece->getKind() == PathDiagnosticPiece::Kind::Event &&
2864 "The final piece must contain a message!");
2865 LastPiece = std::move(Piece);
2866 (*Notes)[ErrorNode].push_back(x: LastPiece);
2867 }
2868 }
2869 break;
2870 }
2871
2872 for (auto &V : visitors) {
2873 auto P = V->VisitNode(Succ: NextNode, BRC, BR&: *R);
2874 if (P)
2875 (*Notes)[NextNode].push_back(x: std::move(P));
2876 }
2877
2878 if (!R->isValid())
2879 break;
2880
2881 NextNode = Pred;
2882 }
2883
2884 return Notes;
2885}
2886
2887std::optional<PathDiagnosticBuilder> PathDiagnosticBuilder::findValidReport(
2888 ArrayRef<PathSensitiveBugReport *> &bugReports,
2889 PathSensitiveBugReporter &Reporter) {
2890 Z3CrosscheckOracle Z3Oracle(Reporter.getAnalyzerOptions());
2891
2892 BugPathGetter BugGraph(&Reporter.getGraph(), bugReports);
2893
2894 while (BugPathInfo *BugPath = BugGraph.getNextBugPath()) {
2895 // Find the BugReport with the original location.
2896 PathSensitiveBugReport *R = BugPath->Report;
2897 assert(R && "No original report found for sliced graph.");
2898 assert(R->isValid() && "Report selected by trimmed graph marked invalid.");
2899 const ExplodedNode *ErrorNode = BugPath->ErrorNode;
2900
2901 // Register refutation visitors first, if they mark the bug invalid no
2902 // further analysis is required
2903 R->addVisitor<LikelyFalsePositiveSuppressionBRVisitor>();
2904
2905 // Register additional node visitors.
2906 R->addVisitor<NilReceiverBRVisitor>();
2907 R->addVisitor<ConditionBRVisitor>();
2908 R->addVisitor<TagVisitor>();
2909
2910 BugReporterContext BRC(Reporter);
2911
2912 // Run all visitors on a given graph, once.
2913 std::unique_ptr<VisitorsDiagnosticsTy> visitorNotes =
2914 generateVisitorsDiagnostics(R, ErrorNode, BRC);
2915
2916 if (R->isValid()) {
2917 if (Reporter.getAnalyzerOptions().ShouldCrosscheckWithZ3) {
2918 llvm::TimeTraceScope TCS{"Crosscheck with Z3"};
2919 // If crosscheck is enabled, remove all visitors, add the refutation
2920 // visitor and check again
2921 R->clearVisitors();
2922 Z3CrosscheckVisitor::Z3Result CrosscheckResult;
2923 R->addVisitor<Z3CrosscheckVisitor>(ConstructorArgs&: CrosscheckResult,
2924 ConstructorArgs: Reporter.getAnalyzerOptions());
2925
2926 // We don't overwrite the notes inserted by other visitors because the
2927 // refutation manager does not add any new note to the path
2928 generateVisitorsDiagnostics(R, ErrorNode: BugPath->ErrorNode, BRC);
2929 switch (Z3Oracle.interpretQueryResult(Meta: CrosscheckResult)) {
2930 case Z3CrosscheckOracle::RejectReport:
2931 ++NumTimesReportRefuted;
2932 R->markInvalid(Tag: "Infeasible constraints", /*Data=*/nullptr);
2933 continue;
2934 case Z3CrosscheckOracle::RejectEQClass:
2935 ++NumTimesReportEQClassAborted;
2936 return {};
2937 case Z3CrosscheckOracle::AcceptReport:
2938 ++NumTimesReportPassesZ3;
2939 break;
2940 }
2941 }
2942
2943 assert(R->isValid());
2944 return PathDiagnosticBuilder(std::move(BRC), std::move(BugPath->BugPath),
2945 BugPath->Report, BugPath->ErrorNode,
2946 std::move(visitorNotes));
2947 }
2948 }
2949
2950 ++NumTimesReportEQClassWasExhausted;
2951 return {};
2952}
2953
2954std::unique_ptr<DiagnosticForConsumerMapTy>
2955PathSensitiveBugReporter::generatePathDiagnostics(
2956 ArrayRef<std::unique_ptr<PathDiagnosticConsumer>> consumers,
2957 ArrayRef<PathSensitiveBugReport *> &bugReports) {
2958 assert(!bugReports.empty());
2959
2960 auto Out = std::make_unique<DiagnosticForConsumerMapTy>();
2961
2962 std::optional<PathDiagnosticBuilder> PDB =
2963 PathDiagnosticBuilder::findValidReport(bugReports, Reporter&: *this);
2964
2965 if (PDB) {
2966 for (const auto &PC : consumers) {
2967 if (std::unique_ptr<PathDiagnostic> PD = PDB->generate(PDC: PC.get())) {
2968 (*Out)[PC.get()] = std::move(PD);
2969 }
2970 }
2971 }
2972
2973 return Out;
2974}
2975
2976void BugReporter::emitReport(std::unique_ptr<BugReport> R) {
2977 bool ValidSourceLoc = R->getLocation().isValid();
2978 assert(ValidSourceLoc);
2979 // If we mess up in a release build, we'd still prefer to just drop the bug
2980 // instead of trying to go on.
2981 if (!ValidSourceLoc)
2982 return;
2983
2984 // If the user asked to suppress this report, we should skip it.
2985 if (UserSuppressions.isSuppressed(*R))
2986 return;
2987
2988 // Compute the bug report's hash to determine its equivalence class.
2989 llvm::FoldingSetNodeID ID;
2990 R->Profile(hash&: ID);
2991
2992 // Lookup the equivance class. If there isn't one, create it.
2993 void *InsertPos;
2994 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
2995
2996 if (!EQ) {
2997 EQ = new BugReportEquivClass(std::move(R));
2998 EQClasses.InsertNode(N: EQ, InsertPos);
2999 EQClassesVector.push_back(x: EQ);
3000 } else
3001 EQ->AddReport(R: std::move(R));
3002}
3003
3004void PathSensitiveBugReporter::emitReport(std::unique_ptr<BugReport> R) {
3005 if (auto PR = dyn_cast<PathSensitiveBugReport>(Val: R.get()))
3006 if (const ExplodedNode *E = PR->getErrorNode()) {
3007 // An error node must either be a sink or have a tag, otherwise
3008 // it could get reclaimed before the path diagnostic is created.
3009 assert((E->isSink() || E->getLocation().getTag()) &&
3010 "Error node must either be a sink or have a tag");
3011
3012 const AnalysisDeclContext *DeclCtx =
3013 E->getLocationContext()->getAnalysisDeclContext();
3014 // The source of autosynthesized body can be handcrafted AST or a model
3015 // file. The locations from handcrafted ASTs have no valid source
3016 // locations and have to be discarded. Locations from model files should
3017 // be preserved for processing and reporting.
3018 if (DeclCtx->isBodyAutosynthesized() &&
3019 !DeclCtx->isBodyAutosynthesizedFromModelFile())
3020 return;
3021 }
3022
3023 BugReporter::emitReport(R: std::move(R));
3024}
3025
3026//===----------------------------------------------------------------------===//
3027// Emitting reports in equivalence classes.
3028//===----------------------------------------------------------------------===//
3029
3030namespace {
3031
3032struct FRIEC_WLItem {
3033 const ExplodedNode *N;
3034 ExplodedNode::const_succ_iterator I, E;
3035
3036 FRIEC_WLItem(const ExplodedNode *n)
3037 : N(n), I(N->succ_begin()), E(N->succ_end()) {}
3038};
3039
3040} // namespace
3041
3042BugReport *PathSensitiveBugReporter::findReportInEquivalenceClass(
3043 BugReportEquivClass &EQ, SmallVectorImpl<BugReport *> &bugReports) {
3044 // If we don't need to suppress any of the nodes because they are
3045 // post-dominated by a sink, simply add all the nodes in the equivalence class
3046 // to 'Nodes'. Any of the reports will serve as a "representative" report.
3047 assert(EQ.getReports().size() > 0);
3048 const BugType& BT = EQ.getReports()[0]->getBugType();
3049 if (!BT.isSuppressOnSink()) {
3050 BugReport *R = EQ.getReports()[0].get();
3051 for (auto &J : EQ.getReports()) {
3052 if (auto *PR = dyn_cast<PathSensitiveBugReport>(Val: J.get())) {
3053 R = PR;
3054 bugReports.push_back(Elt: PR);
3055 }
3056 }
3057 return R;
3058 }
3059
3060 // For bug reports that should be suppressed when all paths are post-dominated
3061 // by a sink node, iterate through the reports in the equivalence class
3062 // until we find one that isn't post-dominated (if one exists). We use a
3063 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write
3064 // this as a recursive function, but we don't want to risk blowing out the
3065 // stack for very long paths.
3066 BugReport *exampleReport = nullptr;
3067
3068 for (const auto &I: EQ.getReports()) {
3069 auto *R = dyn_cast<PathSensitiveBugReport>(Val: I.get());
3070 if (!R)
3071 continue;
3072
3073 const ExplodedNode *errorNode = R->getErrorNode();
3074 if (errorNode->isSink()) {
3075 llvm_unreachable(
3076 "BugType::isSuppressSink() should not be 'true' for sink end nodes");
3077 }
3078 // No successors? By definition this nodes isn't post-dominated by a sink.
3079 if (errorNode->succ_empty()) {
3080 bugReports.push_back(Elt: R);
3081 if (!exampleReport)
3082 exampleReport = R;
3083 continue;
3084 }
3085
3086 // See if we are in a no-return CFG block. If so, treat this similarly
3087 // to being post-dominated by a sink. This works better when the analysis
3088 // is incomplete and we have never reached the no-return function call(s)
3089 // that we'd inevitably bump into on this path.
3090 if (const CFGBlock *ErrorB = errorNode->getCFGBlock())
3091 if (ErrorB->isInevitablySinking())
3092 continue;
3093
3094 // At this point we know that 'N' is not a sink and it has at least one
3095 // successor. Use a DFS worklist to find a non-sink end-of-path node.
3096 using WLItem = FRIEC_WLItem;
3097 using DFSWorkList = SmallVector<WLItem, 10>;
3098
3099 llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
3100
3101 DFSWorkList WL;
3102 WL.push_back(Elt: errorNode);
3103 Visited[errorNode] = 1;
3104
3105 while (!WL.empty()) {
3106 WLItem &WI = WL.back();
3107 assert(!WI.N->succ_empty());
3108
3109 for (; WI.I != WI.E; ++WI.I) {
3110 const ExplodedNode *Succ = *WI.I;
3111 // End-of-path node?
3112 if (Succ->succ_empty()) {
3113 // If we found an end-of-path node that is not a sink.
3114 if (!Succ->isSink()) {
3115 bugReports.push_back(Elt: R);
3116 if (!exampleReport)
3117 exampleReport = R;
3118 WL.clear();
3119 break;
3120 }
3121 // Found a sink? Continue on to the next successor.
3122 continue;
3123 }
3124 // Mark the successor as visited. If it hasn't been explored,
3125 // enqueue it to the DFS worklist.
3126 unsigned &mark = Visited[Succ];
3127 if (!mark) {
3128 mark = 1;
3129 WL.push_back(Elt: Succ);
3130 break;
3131 }
3132 }
3133
3134 // The worklist may have been cleared at this point. First
3135 // check if it is empty before checking the last item.
3136 if (!WL.empty() && &WL.back() == &WI)
3137 WL.pop_back();
3138 }
3139 }
3140
3141 // ExampleReport will be NULL if all the nodes in the equivalence class
3142 // were post-dominated by sinks.
3143 return exampleReport;
3144}
3145
3146void BugReporter::FlushReport(BugReportEquivClass &EQ) {
3147 llvm::TimeTraceScope TCS{timeTraceName(EQ), [&]() {
3148 return timeTraceMetadata(EQ, SM: getSourceManager());
3149 }};
3150 SmallVector<BugReport*, 10> bugReports;
3151 BugReport *report = findReportInEquivalenceClass(eqClass&: EQ, bugReports);
3152 if (!report)
3153 return;
3154
3155 // See whether we need to silence the checker/package.
3156 for (const std::string &CheckerOrPackage :
3157 getAnalyzerOptions().SilencedCheckersAndPackages) {
3158 if (report->getBugType().getCheckerName().starts_with(Prefix: CheckerOrPackage))
3159 return;
3160 }
3161
3162 ArrayRef Consumers = getPathDiagnosticConsumers();
3163 std::unique_ptr<DiagnosticForConsumerMapTy> Diagnostics =
3164 generateDiagnosticForConsumerMap(exampleReport: report, consumers: Consumers, bugReports);
3165
3166 for (auto &P : *Diagnostics) {
3167 PathDiagnosticConsumer *Consumer = P.first;
3168 std::unique_ptr<PathDiagnostic> &PD = P.second;
3169
3170 // If the path is empty, generate a single step path with the location
3171 // of the issue.
3172 if (PD->path.empty()) {
3173 PathDiagnosticLocation L = report->getLocation();
3174 auto piece = std::make_unique<PathDiagnosticEventPiece>(
3175 args&: L, args: report->getDescription());
3176 for (SourceRange Range : report->getRanges())
3177 piece->addRange(R: Range);
3178 PD->setEndOfPath(std::move(piece));
3179 }
3180
3181 PathPieces &Pieces = PD->getMutablePieces();
3182 if (getAnalyzerOptions().ShouldDisplayNotesAsEvents) {
3183 // For path diagnostic consumers that don't support extra notes,
3184 // we may optionally convert those to path notes.
3185 for (const auto &I : llvm::reverse(C: report->getNotes())) {
3186 PathDiagnosticNotePiece *Piece = I.get();
3187 auto ConvertedPiece = std::make_shared<PathDiagnosticEventPiece>(
3188 args: Piece->getLocation(), args: Piece->getString());
3189 for (const auto &R: Piece->getRanges())
3190 ConvertedPiece->addRange(R);
3191
3192 Pieces.push_front(x: std::move(ConvertedPiece));
3193 }
3194 } else {
3195 for (const auto &I : llvm::reverse(C: report->getNotes()))
3196 Pieces.push_front(x: I);
3197 }
3198
3199 for (const auto &I : report->getFixits())
3200 Pieces.back()->addFixit(F: I);
3201
3202 updateExecutedLinesWithDiagnosticPieces(PD&: *PD);
3203
3204 // If we are debugging, let's have the entry point as the first note.
3205 if (getAnalyzerOptions().AnalyzerDisplayProgress ||
3206 getAnalyzerOptions().AnalyzerNoteAnalysisEntryPoints) {
3207 const Decl *EntryPoint = getAnalysisEntryPoint();
3208 Pieces.push_front(x: std::make_shared<PathDiagnosticEventPiece>(
3209 args: PathDiagnosticLocation{EntryPoint->getLocation(), getSourceManager()},
3210 args: "[debug] analyzing from " +
3211 AnalysisDeclContext::getFunctionName(D: EntryPoint)));
3212 }
3213 Consumer->HandlePathDiagnostic(D: std::move(PD));
3214 }
3215}
3216
3217/// Insert all lines participating in the function signature \p Signature
3218/// into \p ExecutedLines.
3219static void populateExecutedLinesWithFunctionSignature(
3220 const Decl *Signature, const SourceManager &SM,
3221 FilesToLineNumsMap &ExecutedLines) {
3222 SourceRange SignatureSourceRange;
3223 const Stmt* Body = Signature->getBody();
3224 if (const auto FD = dyn_cast<FunctionDecl>(Val: Signature)) {
3225 SignatureSourceRange = FD->getSourceRange();
3226 } else if (const auto OD = dyn_cast<ObjCMethodDecl>(Val: Signature)) {
3227 SignatureSourceRange = OD->getSourceRange();
3228 } else {
3229 return;
3230 }
3231 SourceLocation Start = SignatureSourceRange.getBegin();
3232 SourceLocation End = Body ? Body->getSourceRange().getBegin()
3233 : SignatureSourceRange.getEnd();
3234 if (!Start.isValid() || !End.isValid())
3235 return;
3236 unsigned StartLine = SM.getExpansionLineNumber(Loc: Start);
3237 unsigned EndLine = SM.getExpansionLineNumber(Loc: End);
3238
3239 FileID FID = SM.getFileID(SpellingLoc: SM.getExpansionLoc(Loc: Start));
3240 for (unsigned Line = StartLine; Line <= EndLine; Line++)
3241 ExecutedLines[FID].insert(x: Line);
3242}
3243
3244static void populateExecutedLinesWithStmt(
3245 const Stmt *S, const SourceManager &SM,
3246 FilesToLineNumsMap &ExecutedLines) {
3247 SourceLocation Loc = S->getSourceRange().getBegin();
3248 if (!Loc.isValid())
3249 return;
3250 SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc);
3251 FileID FID = SM.getFileID(SpellingLoc: ExpansionLoc);
3252 unsigned LineNo = SM.getExpansionLineNumber(Loc: ExpansionLoc);
3253 ExecutedLines[FID].insert(x: LineNo);
3254}
3255
3256/// \return all executed lines including function signatures on the path
3257/// starting from \p N.
3258static std::unique_ptr<FilesToLineNumsMap>
3259findExecutedLines(const SourceManager &SM, const ExplodedNode *N) {
3260 auto ExecutedLines = std::make_unique<FilesToLineNumsMap>();
3261
3262 while (N) {
3263 if (N->getFirstPred() == nullptr) {
3264 // First node: show signature of the entrance point.
3265 const Decl *D = N->getLocationContext()->getDecl();
3266 populateExecutedLinesWithFunctionSignature(Signature: D, SM, ExecutedLines&: *ExecutedLines);
3267 } else if (auto CE = N->getLocationAs<CallEnter>()) {
3268 // Inlined function: show signature.
3269 const Decl* D = CE->getCalleeContext()->getDecl();
3270 populateExecutedLinesWithFunctionSignature(Signature: D, SM, ExecutedLines&: *ExecutedLines);
3271 } else if (const Stmt *S = N->getStmtForDiagnostics()) {
3272 populateExecutedLinesWithStmt(S, SM, ExecutedLines&: *ExecutedLines);
3273
3274 // Show extra context for some parent kinds.
3275 const Stmt *P = N->getParentMap().getParent(S);
3276
3277 // The path exploration can die before the node with the associated
3278 // return statement is generated, but we do want to show the whole
3279 // return.
3280 if (const auto *RS = dyn_cast_or_null<ReturnStmt>(Val: P)) {
3281 populateExecutedLinesWithStmt(S: RS, SM, ExecutedLines&: *ExecutedLines);
3282 P = N->getParentMap().getParent(S: RS);
3283 }
3284
3285 if (isa_and_nonnull<SwitchCase, LabelStmt>(Val: P))
3286 populateExecutedLinesWithStmt(S: P, SM, ExecutedLines&: *ExecutedLines);
3287 }
3288
3289 N = N->getFirstPred();
3290 }
3291 return ExecutedLines;
3292}
3293
3294std::unique_ptr<DiagnosticForConsumerMapTy>
3295BugReporter::generateDiagnosticForConsumerMap(
3296 BugReport *exampleReport,
3297 ArrayRef<std::unique_ptr<PathDiagnosticConsumer>> consumers,
3298 ArrayRef<BugReport *> bugReports) {
3299 auto *basicReport = cast<BasicBugReport>(Val: exampleReport);
3300 auto Out = std::make_unique<DiagnosticForConsumerMapTy>();
3301 for (const auto &Consumer : consumers)
3302 (*Out)[Consumer.get()] =
3303 generateDiagnosticForBasicReport(R: basicReport, AnalysisEntryPoint);
3304 return Out;
3305}
3306
3307static PathDiagnosticCallPiece *
3308getFirstStackedCallToHeaderFile(PathDiagnosticCallPiece *CP,
3309 const SourceManager &SMgr) {
3310 SourceLocation CallLoc = CP->callEnter.asLocation();
3311
3312 // If the call is within a macro, don't do anything (for now).
3313 if (CallLoc.isMacroID())
3314 return nullptr;
3315
3316 assert(AnalysisManager::isInCodeFile(CallLoc, SMgr) &&
3317 "The call piece should not be in a header file.");
3318
3319 // Check if CP represents a path through a function outside of the main file.
3320 if (!AnalysisManager::isInCodeFile(SL: CP->callEnterWithin.asLocation(), SM: SMgr))
3321 return CP;
3322
3323 const PathPieces &Path = CP->path;
3324 if (Path.empty())
3325 return nullptr;
3326
3327 // Check if the last piece in the callee path is a call to a function outside
3328 // of the main file.
3329 if (auto *CPInner = dyn_cast<PathDiagnosticCallPiece>(Val: Path.back().get()))
3330 return getFirstStackedCallToHeaderFile(CP: CPInner, SMgr);
3331
3332 // Otherwise, the last piece is in the main file.
3333 return nullptr;
3334}
3335
3336static void resetDiagnosticLocationToMainFile(PathDiagnostic &PD) {
3337 if (PD.path.empty())
3338 return;
3339
3340 PathDiagnosticPiece *LastP = PD.path.back().get();
3341 assert(LastP);
3342 const SourceManager &SMgr = LastP->getLocation().getManager();
3343
3344 // We only need to check if the report ends inside headers, if the last piece
3345 // is a call piece.
3346 if (auto *CP = dyn_cast<PathDiagnosticCallPiece>(Val: LastP)) {
3347 CP = getFirstStackedCallToHeaderFile(CP, SMgr);
3348 if (CP) {
3349 // Mark the piece.
3350 CP->setAsLastInMainSourceFile();
3351
3352 // Update the path diagnostic message.
3353 const auto *ND = dyn_cast<NamedDecl>(Val: CP->getCallee());
3354 if (ND) {
3355 SmallString<200> buf;
3356 llvm::raw_svector_ostream os(buf);
3357 os << " (within a call to '" << ND->getDeclName() << "')";
3358 PD.appendToDesc(S: os.str());
3359 }
3360
3361 // Reset the report containing declaration and location.
3362 PD.setDeclWithIssue(CP->getCaller());
3363 PD.setLocation(CP->getLocation());
3364
3365 return;
3366 }
3367 }
3368}
3369
3370std::unique_ptr<DiagnosticForConsumerMapTy>
3371PathSensitiveBugReporter::generateDiagnosticForConsumerMap(
3372 BugReport *exampleReport,
3373 ArrayRef<std::unique_ptr<PathDiagnosticConsumer>> consumers,
3374 ArrayRef<BugReport *> bugReports) {
3375 if (isa<BasicBugReport>(Val: exampleReport))
3376 return BugReporter::generateDiagnosticForConsumerMap(exampleReport,
3377 consumers, bugReports);
3378
3379 // Generate the full path sensitive diagnostic, using the generation scheme
3380 // specified by the PathDiagnosticConsumer. Note that we have to generate
3381 // path diagnostics even for consumers which do not support paths, because
3382 // the BugReporterVisitors may mark this bug as a false positive.
3383 assert(!bugReports.empty());
3384 MaxBugClassSize.updateMax(Value: bugReports.size());
3385
3386 // Avoid copying the whole array because there may be a lot of reports.
3387 ArrayRef<PathSensitiveBugReport *> convertedArrayOfReports(
3388 reinterpret_cast<PathSensitiveBugReport *const *>(&*bugReports.begin()),
3389 reinterpret_cast<PathSensitiveBugReport *const *>(&*bugReports.end()));
3390 std::unique_ptr<DiagnosticForConsumerMapTy> Out = generatePathDiagnostics(
3391 consumers, bugReports&: convertedArrayOfReports);
3392
3393 if (Out->empty())
3394 return Out;
3395
3396 MaxValidBugClassSize.updateMax(Value: bugReports.size());
3397
3398 // Examine the report and see if the last piece is in a header. Reset the
3399 // report location to the last piece in the main source file.
3400 const AnalyzerOptions &Opts = getAnalyzerOptions();
3401 for (auto const &P : *Out)
3402 if (Opts.ShouldReportIssuesInMainSourceFile && !Opts.AnalyzeAll)
3403 resetDiagnosticLocationToMainFile(PD&: *P.second);
3404
3405 return Out;
3406}
3407
3408void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3409 const CheckerFrontend *Checker,
3410 StringRef Name, StringRef Category,
3411 StringRef Str, PathDiagnosticLocation Loc,
3412 ArrayRef<SourceRange> Ranges,
3413 ArrayRef<FixItHint> Fixits) {
3414 EmitBasicReport(DeclWithIssue, CheckerName: Checker->getName(), BugName: Name, BugCategory: Category, BugStr: Str, Loc,
3415 Ranges, Fixits);
3416}
3417
3418void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3419 CheckerNameRef CheckName,
3420 StringRef name, StringRef category,
3421 StringRef str, PathDiagnosticLocation Loc,
3422 ArrayRef<SourceRange> Ranges,
3423 ArrayRef<FixItHint> Fixits) {
3424 // 'BT' is owned by BugReporter.
3425 BugType *BT = getBugTypeForName(CheckerName: CheckName, name, category);
3426 auto R = std::make_unique<BasicBugReport>(args&: *BT, args&: str, args&: Loc);
3427 R->setDeclWithIssue(DeclWithIssue);
3428 for (const auto &SR : Ranges)
3429 R->addRange(R: SR);
3430 for (const auto &FH : Fixits)
3431 R->addFixItHint(F: FH);
3432 emitReport(R: std::move(R));
3433}
3434
3435BugType *BugReporter::getBugTypeForName(CheckerNameRef CheckName,
3436 StringRef name, StringRef category) {
3437 SmallString<136> fullDesc;
3438 llvm::raw_svector_ostream(fullDesc)
3439 << CheckName << ":" << name << ":" << category;
3440 std::unique_ptr<BugType> &BT = StrBugTypes[fullDesc];
3441 if (!BT)
3442 BT = std::make_unique<BugType>(args&: CheckName, args&: name, args&: category);
3443 return BT.get();
3444}
3445