1 //===- BugReporter.cpp - Generate PathDiagnostics for bugs ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines BugReporter, a utility class for generating
13 //===----------------------------------------------------------------------===//
15 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclBase.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/ParentMap.h"
22 #include "clang/AST/Stmt.h"
23 #include "clang/AST/StmtCXX.h"
24 #include "clang/AST/StmtObjC.h"
25 #include "clang/Analysis/AnalysisDeclContext.h"
26 #include "clang/Analysis/CFG.h"
27 #include "clang/Analysis/CFGStmtMap.h"
28 #include "clang/Analysis/ProgramPoint.h"
29 #include "clang/Basic/LLVM.h"
30 #include "clang/Basic/SourceLocation.h"
31 #include "clang/Basic/SourceManager.h"
32 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
33 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
34 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
35 #include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
36 #include "clang/StaticAnalyzer/Core/Checker.h"
37 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
38 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
39 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
40 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
41 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
42 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
43 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
44 #include "llvm/ADT/ArrayRef.h"
45 #include "llvm/ADT/DenseMap.h"
46 #include "llvm/ADT/DenseSet.h"
47 #include "llvm/ADT/FoldingSet.h"
48 #include "llvm/ADT/None.h"
49 #include "llvm/ADT/Optional.h"
50 #include "llvm/ADT/STLExtras.h"
51 #include "llvm/ADT/SmallPtrSet.h"
52 #include "llvm/ADT/SmallString.h"
53 #include "llvm/ADT/SmallVector.h"
54 #include "llvm/ADT/Statistic.h"
55 #include "llvm/ADT/StringRef.h"
56 #include "llvm/ADT/iterator_range.h"
57 #include "llvm/Support/Casting.h"
58 #include "llvm/Support/Compiler.h"
59 #include "llvm/Support/ErrorHandling.h"
60 #include "llvm/Support/MemoryBuffer.h"
61 #include "llvm/Support/raw_ostream.h"
73 using namespace clang;
76 #define DEBUG_TYPE "BugReporter"
78 STATISTIC(MaxBugClassSize,
79 "The maximum number of bug reports in the same equivalence class");
80 STATISTIC(MaxValidBugClassSize,
81 "The maximum number of bug reports in the same equivalence class "
82 "where at least one report is valid (not suppressed)");
84 BugReporterVisitor::~BugReporterVisitor() = default;
86 void BugReporterContext::anchor() {}
88 //===----------------------------------------------------------------------===//
89 // Helper routines for walking the ExplodedGraph and fetching statements.
90 //===----------------------------------------------------------------------===//
92 static const Stmt *GetPreviousStmt(const ExplodedNode *N) {
93 for (N = N->getFirstPred(); N; N = N->getFirstPred())
94 if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
100 static inline const Stmt*
101 GetCurrentOrPreviousStmt(const ExplodedNode *N) {
102 if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
105 return GetPreviousStmt(N);
108 //===----------------------------------------------------------------------===//
109 // Diagnostic cleanup.
110 //===----------------------------------------------------------------------===//
112 static PathDiagnosticEventPiece *
113 eventsDescribeSameCondition(PathDiagnosticEventPiece *X,
114 PathDiagnosticEventPiece *Y) {
115 // Prefer diagnostics that come from ConditionBRVisitor over
116 // those that came from TrackConstraintBRVisitor,
117 // unless the one from ConditionBRVisitor is
118 // its generic fallback diagnostic.
119 const void *tagPreferred = ConditionBRVisitor::getTag();
120 const void *tagLesser = TrackConstraintBRVisitor::getTag();
122 if (X->getLocation() != Y->getLocation())
125 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser)
126 return ConditionBRVisitor::isPieceMessageGeneric(X) ? Y : X;
128 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser)
129 return ConditionBRVisitor::isPieceMessageGeneric(Y) ? X : Y;
134 /// An optimization pass over PathPieces that removes redundant diagnostics
135 /// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both
136 /// BugReporterVisitors use different methods to generate diagnostics, with
137 /// one capable of emitting diagnostics in some cases but not in others. This
138 /// can lead to redundant diagnostic pieces at the same point in a path.
139 static void removeRedundantMsgs(PathPieces &path) {
140 unsigned N = path.size();
143 // NOTE: this loop intentionally is not using an iterator. Instead, we
144 // are streaming the path and modifying it in place. This is done by
145 // grabbing the front, processing it, and if we decide to keep it append
146 // it to the end of the path. The entire path is processed in this way.
147 for (unsigned i = 0; i < N; ++i) {
148 auto piece = std::move(path.front());
151 switch (piece->getKind()) {
152 case PathDiagnosticPiece::Call:
153 removeRedundantMsgs(cast<PathDiagnosticCallPiece>(*piece).path);
155 case PathDiagnosticPiece::Macro:
156 removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(*piece).subPieces);
158 case PathDiagnosticPiece::ControlFlow:
160 case PathDiagnosticPiece::Event: {
164 if (auto *nextEvent =
165 dyn_cast<PathDiagnosticEventPiece>(path.front().get())) {
166 auto *event = cast<PathDiagnosticEventPiece>(piece.get());
167 // Check to see if we should keep one of the two pieces. If we
168 // come up with a preference, record which piece to keep, and consume
169 // another piece from the path.
170 if (auto *pieceToKeep =
171 eventsDescribeSameCondition(event, nextEvent)) {
172 piece = std::move(pieceToKeep == event ? piece : path.front());
179 case PathDiagnosticPiece::Note:
182 path.push_back(std::move(piece));
186 /// A map from PathDiagnosticPiece to the LocationContext of the inlined
187 /// function call it represents.
188 using LocationContextMap =
189 llvm::DenseMap<const PathPieces *, const LocationContext *>;
191 /// Recursively scan through a path and prune out calls and macros pieces
192 /// that aren't needed. Return true if afterwards the path contains
193 /// "interesting stuff" which means it shouldn't be pruned from the parent path.
194 static bool removeUnneededCalls(PathPieces &pieces, BugReport *R,
195 LocationContextMap &LCM,
196 bool IsInteresting = false) {
197 bool containsSomethingInteresting = IsInteresting;
198 const unsigned N = pieces.size();
200 for (unsigned i = 0 ; i < N ; ++i) {
201 // Remove the front piece from the path. If it is still something we
202 // want to keep once we are done, we will push it back on the end.
203 auto piece = std::move(pieces.front());
206 switch (piece->getKind()) {
207 case PathDiagnosticPiece::Call: {
208 auto &call = cast<PathDiagnosticCallPiece>(*piece);
209 // Check if the location context is interesting.
210 assert(LCM.count(&call.path));
211 if (!removeUnneededCalls(call.path, R, LCM,
212 R->isInteresting(LCM[&call.path])))
215 containsSomethingInteresting = true;
218 case PathDiagnosticPiece::Macro: {
219 auto ¯o = cast<PathDiagnosticMacroPiece>(*piece);
220 if (!removeUnneededCalls(macro.subPieces, R, LCM, IsInteresting))
222 containsSomethingInteresting = true;
225 case PathDiagnosticPiece::Event: {
226 auto &event = cast<PathDiagnosticEventPiece>(*piece);
228 // We never throw away an event, but we do throw it away wholesale
229 // as part of a path if we throw the entire path away.
230 containsSomethingInteresting |= !event.isPrunable();
233 case PathDiagnosticPiece::ControlFlow:
236 case PathDiagnosticPiece::Note:
240 pieces.push_back(std::move(piece));
243 return containsSomethingInteresting;
246 /// Returns true if the given decl has been implicitly given a body, either by
247 /// the analyzer or by the compiler proper.
248 static bool hasImplicitBody(const Decl *D) {
250 return D->isImplicit() || !D->hasBody();
253 /// Recursively scan through a path and make sure that all call pieces have
256 adjustCallLocations(PathPieces &Pieces,
257 PathDiagnosticLocation *LastCallLocation = nullptr) {
258 for (const auto &I : Pieces) {
259 auto *Call = dyn_cast<PathDiagnosticCallPiece>(I.get());
264 if (LastCallLocation) {
265 bool CallerIsImplicit = hasImplicitBody(Call->getCaller());
266 if (CallerIsImplicit || !Call->callEnter.asLocation().isValid())
267 Call->callEnter = *LastCallLocation;
268 if (CallerIsImplicit || !Call->callReturn.asLocation().isValid())
269 Call->callReturn = *LastCallLocation;
272 // Recursively clean out the subclass. Keep this call around if
273 // it contains any informative diagnostics.
274 PathDiagnosticLocation *ThisCallLocation;
275 if (Call->callEnterWithin.asLocation().isValid() &&
276 !hasImplicitBody(Call->getCallee()))
277 ThisCallLocation = &Call->callEnterWithin;
279 ThisCallLocation = &Call->callEnter;
281 assert(ThisCallLocation && "Outermost call has an invalid location");
282 adjustCallLocations(Call->path, ThisCallLocation);
286 /// Remove edges in and out of C++ default initializer expressions. These are
287 /// for fields that have in-class initializers, as opposed to being initialized
288 /// explicitly in a constructor or braced list.
289 static void removeEdgesToDefaultInitializers(PathPieces &Pieces) {
290 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
291 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get()))
292 removeEdgesToDefaultInitializers(C->path);
294 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get()))
295 removeEdgesToDefaultInitializers(M->subPieces);
297 if (auto *CF = dyn_cast<PathDiagnosticControlFlowPiece>(I->get())) {
298 const Stmt *Start = CF->getStartLocation().asStmt();
299 const Stmt *End = CF->getEndLocation().asStmt();
300 if (Start && isa<CXXDefaultInitExpr>(Start)) {
303 } else if (End && isa<CXXDefaultInitExpr>(End)) {
304 PathPieces::iterator Next = std::next(I);
307 dyn_cast<PathDiagnosticControlFlowPiece>(Next->get())) {
308 NextCF->setStartLocation(CF->getStartLocation());
320 /// Remove all pieces with invalid locations as these cannot be serialized.
321 /// We might have pieces with invalid locations as a result of inlining Body
322 /// Farm generated functions.
323 static void removePiecesWithInvalidLocations(PathPieces &Pieces) {
324 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) {
325 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get()))
326 removePiecesWithInvalidLocations(C->path);
328 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get()))
329 removePiecesWithInvalidLocations(M->subPieces);
331 if (!(*I)->getLocation().isValid() ||
332 !(*I)->getLocation().asLocation().isValid()) {
340 //===----------------------------------------------------------------------===//
341 // PathDiagnosticBuilder and its associated routines and helper objects.
342 //===----------------------------------------------------------------------===//
346 class PathDiagnosticBuilder : public BugReporterContext {
348 PathDiagnosticConsumer *PDC;
351 const LocationContext *LC;
353 PathDiagnosticBuilder(GRBugReporter &br,
354 BugReport *r, InterExplodedGraphMap &Backmap,
355 PathDiagnosticConsumer *pdc)
356 : BugReporterContext(br, Backmap), R(r), PDC(pdc),
357 LC(r->getErrorNode()->getLocationContext()) {}
359 PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N);
361 PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os,
362 const ExplodedNode *N);
364 BugReport *getBugReport() { return R; }
366 Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); }
368 ParentMap& getParentMap() { return LC->getParentMap(); }
370 const Stmt *getParent(const Stmt *S) {
371 return getParentMap().getParent(S);
374 PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S);
376 PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const {
377 return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Minimal;
380 bool supportsLogicalOpControlFlow() const {
381 return PDC ? PDC->supportsLogicalOpControlFlow() : true;
387 PathDiagnosticLocation
388 PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) {
389 if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N))
390 return PathDiagnosticLocation(S, getSourceManager(), LC);
392 return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(),
396 PathDiagnosticLocation
397 PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os,
398 const ExplodedNode *N) {
399 // Slow, but probably doesn't matter.
400 if (os.str().empty())
403 const PathDiagnosticLocation &Loc = ExecutionContinues(N);
406 os << "Execution continues on line "
407 << getSourceManager().getExpansionLineNumber(Loc.asLocation())
410 os << "Execution jumps to the end of the ";
411 const Decl *D = N->getLocationContext()->getDecl();
412 if (isa<ObjCMethodDecl>(D))
414 else if (isa<FunctionDecl>(D))
417 assert(isa<BlockDecl>(D));
418 os << "anonymous block";
426 static const Stmt *getEnclosingParent(const Stmt *S, const ParentMap &PM) {
427 if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S)))
428 return PM.getParentIgnoreParens(S);
430 const Stmt *Parent = PM.getParentIgnoreParens(S);
434 switch (Parent->getStmtClass()) {
435 case Stmt::ForStmtClass:
436 case Stmt::DoStmtClass:
437 case Stmt::WhileStmtClass:
438 case Stmt::ObjCForCollectionStmtClass:
439 case Stmt::CXXForRangeStmtClass:
448 static PathDiagnosticLocation
449 getEnclosingStmtLocation(const Stmt *S, SourceManager &SMgr, const ParentMap &P,
450 const LocationContext *LC, bool allowNestedContexts) {
454 while (const Stmt *Parent = getEnclosingParent(S, P)) {
455 switch (Parent->getStmtClass()) {
456 case Stmt::BinaryOperatorClass: {
457 const auto *B = cast<BinaryOperator>(Parent);
458 if (B->isLogicalOp())
459 return PathDiagnosticLocation(allowNestedContexts ? B : S, SMgr, LC);
462 case Stmt::CompoundStmtClass:
463 case Stmt::StmtExprClass:
464 return PathDiagnosticLocation(S, SMgr, LC);
465 case Stmt::ChooseExprClass:
466 // Similar to '?' if we are referring to condition, just have the edge
467 // point to the entire choose expression.
468 if (allowNestedContexts || cast<ChooseExpr>(Parent)->getCond() == S)
469 return PathDiagnosticLocation(Parent, SMgr, LC);
471 return PathDiagnosticLocation(S, SMgr, LC);
472 case Stmt::BinaryConditionalOperatorClass:
473 case Stmt::ConditionalOperatorClass:
474 // For '?', if we are referring to condition, just have the edge point
475 // to the entire '?' expression.
476 if (allowNestedContexts ||
477 cast<AbstractConditionalOperator>(Parent)->getCond() == S)
478 return PathDiagnosticLocation(Parent, SMgr, LC);
480 return PathDiagnosticLocation(S, SMgr, LC);
481 case Stmt::CXXForRangeStmtClass:
482 if (cast<CXXForRangeStmt>(Parent)->getBody() == S)
483 return PathDiagnosticLocation(S, SMgr, LC);
485 case Stmt::DoStmtClass:
486 return PathDiagnosticLocation(S, SMgr, LC);
487 case Stmt::ForStmtClass:
488 if (cast<ForStmt>(Parent)->getBody() == S)
489 return PathDiagnosticLocation(S, SMgr, LC);
491 case Stmt::IfStmtClass:
492 if (cast<IfStmt>(Parent)->getCond() != S)
493 return PathDiagnosticLocation(S, SMgr, LC);
495 case Stmt::ObjCForCollectionStmtClass:
496 if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S)
497 return PathDiagnosticLocation(S, SMgr, LC);
499 case Stmt::WhileStmtClass:
500 if (cast<WhileStmt>(Parent)->getCond() != S)
501 return PathDiagnosticLocation(S, SMgr, LC);
510 assert(S && "Cannot have null Stmt for PathDiagnosticLocation");
512 return PathDiagnosticLocation(S, SMgr, LC);
515 PathDiagnosticLocation
516 PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) {
517 assert(S && "Null Stmt passed to getEnclosingStmtLocation");
518 return ::getEnclosingStmtLocation(S, getSourceManager(), getParentMap(), LC,
519 /*allowNestedContexts=*/false);
522 //===----------------------------------------------------------------------===//
523 // "Minimal" path diagnostic generation algorithm.
524 //===----------------------------------------------------------------------===//
525 using StackDiagPair =
526 std::pair<PathDiagnosticCallPiece *, const ExplodedNode *>;
527 using StackDiagVector = SmallVector<StackDiagPair, 6>;
529 static void updateStackPiecesWithMessage(PathDiagnosticPiece &P,
530 StackDiagVector &CallStack) {
531 // If the piece contains a special message, add it to all the call
532 // pieces on the active stack.
533 if (auto *ep = dyn_cast<PathDiagnosticEventPiece>(&P)) {
534 if (ep->hasCallStackHint())
535 for (const auto &I : CallStack) {
536 PathDiagnosticCallPiece *CP = I.first;
537 const ExplodedNode *N = I.second;
538 std::string stackMsg = ep->getCallStackMessage(N);
540 // The last message on the path to final bug is the most important
541 // one. Since we traverse the path backwards, do not add the message
542 // if one has been previously added.
543 if (!CP->hasCallStackMessage())
544 CP->setCallStackMessage(stackMsg);
549 static void CompactMacroExpandedPieces(PathPieces &path,
550 const SourceManager& SM);
553 std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForSwitchOP(
554 const ExplodedNode *N,
556 const SourceManager &SM,
557 const LocationContext *LC,
558 PathDiagnosticBuilder &PDB,
559 PathDiagnosticLocation &Start
561 // Figure out what case arm we took.
563 llvm::raw_string_ostream os(sbuf);
564 PathDiagnosticLocation End;
566 if (const Stmt *S = Dst->getLabel()) {
567 End = PathDiagnosticLocation(S, SM, LC);
569 switch (S->getStmtClass()) {
571 os << "No cases match in the switch statement. "
572 "Control jumps to line "
573 << End.asLocation().getExpansionLineNumber();
575 case Stmt::DefaultStmtClass:
576 os << "Control jumps to the 'default' case at line "
577 << End.asLocation().getExpansionLineNumber();
580 case Stmt::CaseStmtClass: {
581 os << "Control jumps to 'case ";
582 const auto *Case = cast<CaseStmt>(S);
583 const Expr *LHS = Case->getLHS()->IgnoreParenCasts();
585 // Determine if it is an enum.
586 bool GetRawInt = true;
588 if (const auto *DR = dyn_cast<DeclRefExpr>(LHS)) {
589 // FIXME: Maybe this should be an assertion. Are there cases
590 // were it is not an EnumConstantDecl?
591 const auto *D = dyn_cast<EnumConstantDecl>(DR->getDecl());
600 os << LHS->EvaluateKnownConstInt(PDB.getASTContext());
602 os << ":' at line " << End.asLocation().getExpansionLineNumber();
607 os << "'Default' branch taken. ";
608 End = PDB.ExecutionContinues(os, N);
610 return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
615 std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForGotoOP(
617 PathDiagnosticBuilder &PDB,
618 PathDiagnosticLocation &Start) {
620 llvm::raw_string_ostream os(sbuf);
621 const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S);
622 os << "Control jumps to line " << End.asLocation().getExpansionLineNumber();
623 return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str());
627 std::shared_ptr<PathDiagnosticControlFlowPiece> generateDiagForBinaryOP(
628 const ExplodedNode *N,
632 const SourceManager &SM,
633 PathDiagnosticBuilder &PDB,
634 const LocationContext *LC) {
635 const auto *B = cast<BinaryOperator>(T);
637 llvm::raw_string_ostream os(sbuf);
638 os << "Left side of '";
639 PathDiagnosticLocation Start, End;
641 if (B->getOpcode() == BO_LAnd) {
645 if (*(Src->succ_begin() + 1) == Dst) {
647 End = PathDiagnosticLocation(B->getLHS(), SM, LC);
649 PathDiagnosticLocation::createOperatorLoc(B, SM);
652 Start = PathDiagnosticLocation(B->getLHS(), SM, LC);
653 End = PDB.ExecutionContinues(N);
656 assert(B->getOpcode() == BO_LOr);
660 if (*(Src->succ_begin() + 1) == Dst) {
662 Start = PathDiagnosticLocation(B->getLHS(), SM, LC);
663 End = PDB.ExecutionContinues(N);
666 End = PathDiagnosticLocation(B->getLHS(), SM, LC);
668 PathDiagnosticLocation::createOperatorLoc(B, SM);
671 return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
675 void generateMinimalDiagForBlockEdge(const ExplodedNode *N, BlockEdge BE,
676 const SourceManager &SM,
677 PathDiagnosticBuilder &PDB,
678 PathDiagnostic &PD) {
679 const LocationContext *LC = N->getLocationContext();
680 const CFGBlock *Src = BE.getSrc();
681 const CFGBlock *Dst = BE.getDst();
682 const Stmt *T = Src->getTerminator();
686 auto Start = PathDiagnosticLocation::createBegin(T, SM, LC);
687 switch (T->getStmtClass()) {
691 case Stmt::GotoStmtClass:
692 case Stmt::IndirectGotoStmtClass: {
693 if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N))
694 PD.getActivePath().push_front(generateDiagForGotoOP(S, PDB, Start));
698 case Stmt::SwitchStmtClass: {
699 PD.getActivePath().push_front(
700 generateDiagForSwitchOP(N, Dst, SM, LC, PDB, Start));
704 case Stmt::BreakStmtClass:
705 case Stmt::ContinueStmtClass: {
707 llvm::raw_string_ostream os(sbuf);
708 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
709 PD.getActivePath().push_front(
710 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str()));
714 // Determine control-flow for ternary '?'.
715 case Stmt::BinaryConditionalOperatorClass:
716 case Stmt::ConditionalOperatorClass: {
718 llvm::raw_string_ostream os(sbuf);
719 os << "'?' condition is ";
721 if (*(Src->succ_begin() + 1) == Dst)
726 PathDiagnosticLocation End = PDB.ExecutionContinues(N);
728 if (const Stmt *S = End.asStmt())
729 End = PDB.getEnclosingStmtLocation(S);
731 PD.getActivePath().push_front(
732 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str()));
736 // Determine control-flow for short-circuited '&&' and '||'.
737 case Stmt::BinaryOperatorClass: {
738 if (!PDB.supportsLogicalOpControlFlow())
741 std::shared_ptr<PathDiagnosticControlFlowPiece> Diag =
742 generateDiagForBinaryOP(N, T, Src, Dst, SM, PDB, LC);
743 PD.getActivePath().push_front(Diag);
747 case Stmt::DoStmtClass:
748 if (*(Src->succ_begin()) == Dst) {
750 llvm::raw_string_ostream os(sbuf);
752 os << "Loop condition is true. ";
753 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
755 if (const Stmt *S = End.asStmt())
756 End = PDB.getEnclosingStmtLocation(S);
758 PD.getActivePath().push_front(
759 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
762 PathDiagnosticLocation End = PDB.ExecutionContinues(N);
764 if (const Stmt *S = End.asStmt())
765 End = PDB.getEnclosingStmtLocation(S);
767 PD.getActivePath().push_front(
768 std::make_shared<PathDiagnosticControlFlowPiece>(
769 Start, End, "Loop condition is false. Exiting loop"));
773 case Stmt::WhileStmtClass:
774 case Stmt::ForStmtClass:
775 if (*(Src->succ_begin() + 1) == Dst) {
777 llvm::raw_string_ostream os(sbuf);
779 os << "Loop condition is false. ";
780 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N);
781 if (const Stmt *S = End.asStmt())
782 End = PDB.getEnclosingStmtLocation(S);
784 PD.getActivePath().push_front(
785 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End,
788 PathDiagnosticLocation End = PDB.ExecutionContinues(N);
789 if (const Stmt *S = End.asStmt())
790 End = PDB.getEnclosingStmtLocation(S);
792 PD.getActivePath().push_front(
793 std::make_shared<PathDiagnosticControlFlowPiece>(
794 Start, End, "Loop condition is true. Entering loop body"));
799 case Stmt::IfStmtClass: {
800 PathDiagnosticLocation End = PDB.ExecutionContinues(N);
802 if (const Stmt *S = End.asStmt())
803 End = PDB.getEnclosingStmtLocation(S);
805 if (*(Src->succ_begin() + 1) == Dst)
806 PD.getActivePath().push_front(
807 std::make_shared<PathDiagnosticControlFlowPiece>(
808 Start, End, "Taking false branch"));
810 PD.getActivePath().push_front(
811 std::make_shared<PathDiagnosticControlFlowPiece>(
812 Start, End, "Taking true branch"));
819 // Cone-of-influence: support the reverse propagation of "interesting" symbols
820 // and values by tracing interesting calculations backwards through evaluated
821 // expressions along a path. This is probably overly complicated, but the idea
822 // is that if an expression computed an "interesting" value, the child
823 // expressions are also likely to be "interesting" as well (which then
824 // propagates to the values they in turn compute). This reverse propagation
825 // is needed to track interesting correlations across function call boundaries,
826 // where formal arguments bind to actual arguments, etc. This is also needed
827 // because the constraint solver sometimes simplifies certain symbolic values
828 // into constants when appropriate, and this complicates reasoning about
829 // interesting values.
830 using InterestingExprs = llvm::DenseSet<const Expr *>;
832 static void reversePropagateIntererstingSymbols(BugReport &R,
833 InterestingExprs &IE,
834 const ProgramState *State,
836 const LocationContext *LCtx) {
837 SVal V = State->getSVal(Ex, LCtx);
838 if (!(R.isInteresting(V) || IE.count(Ex)))
841 switch (Ex->getStmtClass()) {
843 if (!isa<CastExpr>(Ex))
846 case Stmt::BinaryOperatorClass:
847 case Stmt::UnaryOperatorClass: {
848 for (const Stmt *SubStmt : Ex->children()) {
849 if (const auto *child = dyn_cast_or_null<Expr>(SubStmt)) {
851 SVal ChildV = State->getSVal(child, LCtx);
852 R.markInteresting(ChildV);
859 R.markInteresting(V);
862 static void reversePropagateInterestingSymbols(BugReport &R,
863 InterestingExprs &IE,
864 const ProgramState *State,
865 const LocationContext *CalleeCtx)
867 // FIXME: Handle non-CallExpr-based CallEvents.
868 const StackFrameContext *Callee = CalleeCtx->getStackFrame();
869 const Stmt *CallSite = Callee->getCallSite();
870 if (const auto *CE = dyn_cast_or_null<CallExpr>(CallSite)) {
871 if (const auto *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) {
872 FunctionDecl::param_const_iterator PI = FD->param_begin(),
873 PE = FD->param_end();
874 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
875 for (; AI != AE && PI != PE; ++AI, ++PI) {
876 if (const Expr *ArgE = *AI) {
877 if (const ParmVarDecl *PD = *PI) {
878 Loc LV = State->getLValue(PD, CalleeCtx);
879 if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV)))
888 //===----------------------------------------------------------------------===//
889 // Functions for determining if a loop was executed 0 times.
890 //===----------------------------------------------------------------------===//
892 static bool isLoop(const Stmt *Term) {
893 switch (Term->getStmtClass()) {
894 case Stmt::ForStmtClass:
895 case Stmt::WhileStmtClass:
896 case Stmt::ObjCForCollectionStmtClass:
897 case Stmt::CXXForRangeStmtClass:
900 // Note that we intentionally do not include do..while here.
905 static bool isJumpToFalseBranch(const BlockEdge *BE) {
906 const CFGBlock *Src = BE->getSrc();
907 assert(Src->succ_size() == 2);
908 return (*(Src->succ_begin()+1) == BE->getDst());
911 static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) {
915 SubS = PM.getParent(SubS);
920 static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term,
921 const ExplodedNode *N) {
923 Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>();
925 const Stmt *S = SP->getStmt();
926 if (!isContainedByStmt(PM, Term, S))
929 N = N->getFirstPred();
934 static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) {
935 const Stmt *LoopBody = nullptr;
936 switch (Term->getStmtClass()) {
937 case Stmt::CXXForRangeStmtClass: {
938 const auto *FR = cast<CXXForRangeStmt>(Term);
939 if (isContainedByStmt(PM, FR->getInc(), S))
941 if (isContainedByStmt(PM, FR->getLoopVarStmt(), S))
943 LoopBody = FR->getBody();
946 case Stmt::ForStmtClass: {
947 const auto *FS = cast<ForStmt>(Term);
948 if (isContainedByStmt(PM, FS->getInc(), S))
950 LoopBody = FS->getBody();
953 case Stmt::ObjCForCollectionStmtClass: {
954 const auto *FC = cast<ObjCForCollectionStmt>(Term);
955 LoopBody = FC->getBody();
958 case Stmt::WhileStmtClass:
959 LoopBody = cast<WhileStmt>(Term)->getBody();
964 return isContainedByStmt(PM, LoopBody, S);
967 /// Adds a sanitized control-flow diagnostic edge to a path.
968 static void addEdgeToPath(PathPieces &path,
969 PathDiagnosticLocation &PrevLoc,
970 PathDiagnosticLocation NewLoc) {
971 if (!NewLoc.isValid())
974 SourceLocation NewLocL = NewLoc.asLocation();
975 if (NewLocL.isInvalid())
978 if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) {
983 // Ignore self-edges, which occur when there are multiple nodes at the same
985 if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt())
989 std::make_shared<PathDiagnosticControlFlowPiece>(NewLoc, PrevLoc));
993 /// A customized wrapper for CFGBlock::getTerminatorCondition()
994 /// which returns the element for ObjCForCollectionStmts.
995 static const Stmt *getTerminatorCondition(const CFGBlock *B) {
996 const Stmt *S = B->getTerminatorCondition();
997 if (const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(S))
998 return FS->getElement();
1002 static const char StrEnteringLoop[] = "Entering loop body";
1003 static const char StrLoopBodyZero[] = "Loop body executed 0 times";
1004 static const char StrLoopRangeEmpty[] =
1005 "Loop body skipped when range is empty";
1006 static const char StrLoopCollectionEmpty[] =
1007 "Loop body skipped when collection is empty";
1009 static std::unique_ptr<FilesToLineNumsMap>
1010 findExecutedLines(SourceManager &SM, const ExplodedNode *N);
1012 /// Generate diagnostics for the node \p N,
1013 /// and write it into \p PD.
1014 /// \p AddPathEdges Whether diagnostic consumer can generate path arrows
1015 /// showing both row and column.
1016 static void generatePathDiagnosticsForNode(const ExplodedNode *N,
1018 PathDiagnosticLocation &PrevLoc,
1019 PathDiagnosticBuilder &PDB,
1020 LocationContextMap &LCM,
1021 StackDiagVector &CallStack,
1022 InterestingExprs &IE,
1023 bool AddPathEdges) {
1024 ProgramPoint P = N->getLocation();
1025 const SourceManager& SM = PDB.getSourceManager();
1027 // Have we encountered an entrance to a call? It may be
1028 // the case that we have not encountered a matching
1029 // call exit before this point. This means that the path
1030 // terminated within the call itself.
1031 if (auto CE = P.getAs<CallEnter>()) {
1034 // Add an edge to the start of the function.
1035 const StackFrameContext *CalleeLC = CE->getCalleeContext();
1036 const Decl *D = CalleeLC->getDecl();
1037 // Add the edge only when the callee has body. We jump to the beginning
1038 // of the *declaration*, however we expect it to be followed by the
1039 // body. This isn't the case for autosynthesized property accessors in
1040 // Objective-C. No need for a similar extra check for CallExit points
1041 // because the exit edge comes from a statement (i.e. return),
1042 // not from declaration.
1044 addEdgeToPath(PD.getActivePath(), PrevLoc,
1045 PathDiagnosticLocation::createBegin(D, SM));
1048 // Did we visit an entire call?
1049 bool VisitedEntireCall = PD.isWithinCall();
1052 PathDiagnosticCallPiece *C;
1053 if (VisitedEntireCall) {
1054 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front().get());
1056 const Decl *Caller = CE->getLocationContext()->getDecl();
1057 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller);
1060 // Since we just transferred the path over to the call piece,
1061 // reset the mapping from active to location context.
1062 assert(PD.getActivePath().size() == 1 &&
1063 PD.getActivePath().front().get() == C);
1064 LCM[&PD.getActivePath()] = nullptr;
1067 // Record the location context mapping for the path within
1069 assert(LCM[&C->path] == nullptr ||
1070 LCM[&C->path] == CE->getCalleeContext());
1071 LCM[&C->path] = CE->getCalleeContext();
1073 // If this is the first item in the active path, record
1074 // the new mapping from active path to location context.
1075 const LocationContext *&NewLC = LCM[&PD.getActivePath()];
1077 NewLC = N->getLocationContext();
1081 C->setCallee(*CE, SM);
1083 // Update the previous location in the active path.
1084 PrevLoc = C->getLocation();
1086 if (!CallStack.empty()) {
1087 assert(CallStack.back().first == C);
1088 CallStack.pop_back();
1095 // Query the location context here and the previous location
1096 // as processing CallEnter may change the active path.
1097 PDB.LC = N->getLocationContext();
1099 // Record the mapping from the active path to the location
1101 assert(!LCM[&PD.getActivePath()] || LCM[&PD.getActivePath()] == PDB.LC);
1102 LCM[&PD.getActivePath()] = PDB.LC;
1105 // Have we encountered an exit from a function call?
1106 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) {
1108 // We are descending into a call (backwards). Construct
1109 // a new call piece to contain the path pieces for that call.
1110 auto C = PathDiagnosticCallPiece::construct(*CE, SM);
1111 // Record the mapping from call piece to LocationContext.
1112 LCM[&C->path] = CE->getCalleeContext();
1115 const Stmt *S = CE->getCalleeContext()->getCallSite();
1116 // Propagate the interesting symbols accordingly.
1117 if (const auto *Ex = dyn_cast_or_null<Expr>(S)) {
1118 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1119 N->getState().get(), Ex,
1120 N->getLocationContext());
1122 // Add the edge to the return site.
1123 addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn);
1124 PrevLoc.invalidate();
1128 PD.getActivePath().push_front(std::move(C));
1130 // Make the contents of the call the active path for now.
1131 PD.pushActivePath(&P->path);
1132 CallStack.push_back(StackDiagPair(P, N));
1136 if (auto PS = P.getAs<PostStmt>()) {
1140 // For expressions, make sure we propagate the
1141 // interesting symbols correctly.
1142 if (const Expr *Ex = PS->getStmtAs<Expr>())
1143 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE,
1144 N->getState().get(), Ex,
1145 N->getLocationContext());
1147 // Add an edge. If this is an ObjCForCollectionStmt do
1148 // not add an edge here as it appears in the CFG both
1149 // as a terminator and as a terminator condition.
1150 if (!isa<ObjCForCollectionStmt>(PS->getStmt())) {
1151 PathDiagnosticLocation L =
1152 PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC);
1153 addEdgeToPath(PD.getActivePath(), PrevLoc, L);
1156 } else if (auto BE = P.getAs<BlockEdge>()) {
1158 if (!AddPathEdges) {
1159 generateMinimalDiagForBlockEdge(N, *BE, SM, PDB, PD);
1163 // Does this represent entering a call? If so, look at propagating
1164 // interesting symbols across call boundaries.
1165 if (const ExplodedNode *NextNode = N->getFirstPred()) {
1166 const LocationContext *CallerCtx = NextNode->getLocationContext();
1167 const LocationContext *CalleeCtx = PDB.LC;
1168 if (CallerCtx != CalleeCtx && AddPathEdges) {
1169 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE,
1170 N->getState().get(), CalleeCtx);
1174 // Are we jumping to the head of a loop? Add a special diagnostic.
1175 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) {
1176 PathDiagnosticLocation L(Loop, SM, PDB.LC);
1177 const Stmt *Body = nullptr;
1179 if (const auto *FS = dyn_cast<ForStmt>(Loop))
1180 Body = FS->getBody();
1181 else if (const auto *WS = dyn_cast<WhileStmt>(Loop))
1182 Body = WS->getBody();
1183 else if (const auto *OFS = dyn_cast<ObjCForCollectionStmt>(Loop)) {
1184 Body = OFS->getBody();
1185 } else if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Loop)) {
1186 Body = FRS->getBody();
1188 // do-while statements are explicitly excluded here
1190 auto p = std::make_shared<PathDiagnosticEventPiece>(
1191 L, "Looping back to the head "
1193 p->setPrunable(true);
1195 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation());
1196 PD.getActivePath().push_front(std::move(p));
1198 if (const auto *CS = dyn_cast_or_null<CompoundStmt>(Body)) {
1199 addEdgeToPath(PD.getActivePath(), PrevLoc,
1200 PathDiagnosticLocation::createEndBrace(CS, SM));
1204 const CFGBlock *BSrc = BE->getSrc();
1205 ParentMap &PM = PDB.getParentMap();
1207 if (const Stmt *Term = BSrc->getTerminator()) {
1208 // Are we jumping past the loop body without ever executing the
1209 // loop (because the condition was false)?
1211 const Stmt *TermCond = getTerminatorCondition(BSrc);
1213 isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term);
1215 const char *str = nullptr;
1217 if (isJumpToFalseBranch(&*BE)) {
1218 if (!IsInLoopBody) {
1219 if (isa<ObjCForCollectionStmt>(Term)) {
1220 str = StrLoopCollectionEmpty;
1221 } else if (isa<CXXForRangeStmt>(Term)) {
1222 str = StrLoopRangeEmpty;
1224 str = StrLoopBodyZero;
1228 str = StrEnteringLoop;
1232 PathDiagnosticLocation L(TermCond ? TermCond : Term, SM, PDB.LC);
1233 auto PE = std::make_shared<PathDiagnosticEventPiece>(L, str);
1234 PE->setPrunable(true);
1235 addEdgeToPath(PD.getActivePath(), PrevLoc,
1237 PD.getActivePath().push_front(std::move(PE));
1239 } else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) ||
1240 isa<GotoStmt>(Term)) {
1241 PathDiagnosticLocation L(Term, SM, PDB.LC);
1242 addEdgeToPath(PD.getActivePath(), PrevLoc, L);
1248 static std::unique_ptr<PathDiagnostic>
1249 generateEmptyDiagnosticForReport(BugReport *R, SourceManager &SM) {
1250 BugType &BT = R->getBugType();
1251 return llvm::make_unique<PathDiagnostic>(
1252 R->getBugType().getCheckName(), R->getDeclWithIssue(),
1253 R->getBugType().getName(), R->getDescription(),
1254 R->getShortDescription(/*Fallback=*/false), BT.getCategory(),
1255 R->getUniqueingLocation(), R->getUniqueingDecl(),
1256 findExecutedLines(SM, R->getErrorNode()));
1259 static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) {
1264 S = PM.getParentIgnoreParens(S);
1269 if (isa<FullExpr>(S) ||
1270 isa<CXXBindTemporaryExpr>(S) ||
1271 isa<SubstNonTypeTemplateParmExpr>(S))
1280 static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) {
1281 switch (S->getStmtClass()) {
1282 case Stmt::BinaryOperatorClass: {
1283 const auto *BO = cast<BinaryOperator>(S);
1284 if (!BO->isLogicalOp())
1286 return BO->getLHS() == Cond || BO->getRHS() == Cond;
1288 case Stmt::IfStmtClass:
1289 return cast<IfStmt>(S)->getCond() == Cond;
1290 case Stmt::ForStmtClass:
1291 return cast<ForStmt>(S)->getCond() == Cond;
1292 case Stmt::WhileStmtClass:
1293 return cast<WhileStmt>(S)->getCond() == Cond;
1294 case Stmt::DoStmtClass:
1295 return cast<DoStmt>(S)->getCond() == Cond;
1296 case Stmt::ChooseExprClass:
1297 return cast<ChooseExpr>(S)->getCond() == Cond;
1298 case Stmt::IndirectGotoStmtClass:
1299 return cast<IndirectGotoStmt>(S)->getTarget() == Cond;
1300 case Stmt::SwitchStmtClass:
1301 return cast<SwitchStmt>(S)->getCond() == Cond;
1302 case Stmt::BinaryConditionalOperatorClass:
1303 return cast<BinaryConditionalOperator>(S)->getCond() == Cond;
1304 case Stmt::ConditionalOperatorClass: {
1305 const auto *CO = cast<ConditionalOperator>(S);
1306 return CO->getCond() == Cond ||
1307 CO->getLHS() == Cond ||
1308 CO->getRHS() == Cond;
1310 case Stmt::ObjCForCollectionStmtClass:
1311 return cast<ObjCForCollectionStmt>(S)->getElement() == Cond;
1312 case Stmt::CXXForRangeStmtClass: {
1313 const auto *FRS = cast<CXXForRangeStmt>(S);
1314 return FRS->getCond() == Cond || FRS->getRangeInit() == Cond;
1321 static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) {
1322 if (const auto *FS = dyn_cast<ForStmt>(FL))
1323 return FS->getInc() == S || FS->getInit() == S;
1324 if (const auto *FRS = dyn_cast<CXXForRangeStmt>(FL))
1325 return FRS->getInc() == S || FRS->getRangeStmt() == S ||
1326 FRS->getLoopVarStmt() || FRS->getRangeInit() == S;
1330 using OptimizedCallsSet = llvm::DenseSet<const PathDiagnosticCallPiece *>;
1332 /// Adds synthetic edges from top-level statements to their subexpressions.
1334 /// This avoids a "swoosh" effect, where an edge from a top-level statement A
1335 /// points to a sub-expression B.1 that's not at the start of B. In these cases,
1336 /// we'd like to see an edge from A to B, then another one from B to B.1.
1337 static void addContextEdges(PathPieces &pieces, SourceManager &SM,
1338 const ParentMap &PM, const LocationContext *LCtx) {
1339 PathPieces::iterator Prev = pieces.end();
1340 for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E;
1342 auto *Piece = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1347 PathDiagnosticLocation SrcLoc = Piece->getStartLocation();
1348 SmallVector<PathDiagnosticLocation, 4> SrcContexts;
1350 PathDiagnosticLocation NextSrcContext = SrcLoc;
1351 const Stmt *InnerStmt = nullptr;
1352 while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) {
1353 SrcContexts.push_back(NextSrcContext);
1354 InnerStmt = NextSrcContext.asStmt();
1355 NextSrcContext = getEnclosingStmtLocation(InnerStmt, SM, PM, LCtx,
1356 /*allowNested=*/true);
1359 // Repeatedly split the edge as necessary.
1360 // This is important for nested logical expressions (||, &&, ?:) where we
1361 // want to show all the levels of context.
1363 const Stmt *Dst = Piece->getEndLocation().getStmtOrNull();
1365 // We are looking at an edge. Is the destination within a larger
1367 PathDiagnosticLocation DstContext =
1368 getEnclosingStmtLocation(Dst, SM, PM, LCtx, /*allowNested=*/true);
1369 if (!DstContext.isValid() || DstContext.asStmt() == Dst)
1372 // If the source is in the same context, we're already good.
1373 if (std::find(SrcContexts.begin(), SrcContexts.end(), DstContext) !=
1377 // Update the subexpression node to point to the context edge.
1378 Piece->setStartLocation(DstContext);
1380 // Try to extend the previous edge if it's at the same level as the source
1383 auto *PrevPiece = dyn_cast<PathDiagnosticControlFlowPiece>(Prev->get());
1386 if (const Stmt *PrevSrc =
1387 PrevPiece->getStartLocation().getStmtOrNull()) {
1388 const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM);
1389 if (PrevSrcParent ==
1390 getStmtParent(DstContext.getStmtOrNull(), PM)) {
1391 PrevPiece->setEndLocation(DstContext);
1398 // Otherwise, split the current edge into a context edge and a
1399 // subexpression edge. Note that the context statement may itself have
1402 std::make_shared<PathDiagnosticControlFlowPiece>(SrcLoc, DstContext);
1404 I = pieces.insert(I, std::move(P));
1409 /// Move edges from a branch condition to a branch target
1410 /// when the condition is simple.
1412 /// This restructures some of the work of addContextEdges. That function
1413 /// creates edges this may destroy, but they work together to create a more
1414 /// aesthetically set of edges around branches. After the call to
1415 /// addContextEdges, we may have (1) an edge to the branch, (2) an edge from
1416 /// the branch to the branch condition, and (3) an edge from the branch
1417 /// condition to the branch target. We keep (1), but may wish to remove (2)
1418 /// and move the source of (3) to the branch if the branch condition is simple.
1419 static void simplifySimpleBranches(PathPieces &pieces) {
1420 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) {
1421 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1426 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1427 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1429 if (!s1Start || !s1End)
1432 PathPieces::iterator NextI = I; ++NextI;
1436 PathDiagnosticControlFlowPiece *PieceNextI = nullptr;
1442 const auto *EV = dyn_cast<PathDiagnosticEventPiece>(NextI->get());
1444 StringRef S = EV->getString();
1445 if (S == StrEnteringLoop || S == StrLoopBodyZero ||
1446 S == StrLoopCollectionEmpty || S == StrLoopRangeEmpty) {
1453 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1460 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1461 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1463 if (!s2Start || !s2End || s1End != s2Start)
1466 // We only perform this transformation for specific branch kinds.
1467 // We don't want to do this for do..while, for example.
1468 if (!(isa<ForStmt>(s1Start) || isa<WhileStmt>(s1Start) ||
1469 isa<IfStmt>(s1Start) || isa<ObjCForCollectionStmt>(s1Start) ||
1470 isa<CXXForRangeStmt>(s1Start)))
1473 // Is s1End the branch condition?
1474 if (!isConditionForTerminator(s1Start, s1End))
1477 // Perform the hoisting by eliminating (2) and changing the start
1479 PieceNextI->setStartLocation(PieceI->getStartLocation());
1480 I = pieces.erase(I);
1484 /// Returns the number of bytes in the given (character-based) SourceRange.
1486 /// If the locations in the range are not on the same line, returns None.
1488 /// Note that this does not do a precise user-visible character or column count.
1489 static Optional<size_t> getLengthOnSingleLine(SourceManager &SM,
1490 SourceRange Range) {
1491 SourceRange ExpansionRange(SM.getExpansionLoc(Range.getBegin()),
1492 SM.getExpansionRange(Range.getEnd()).getEnd());
1494 FileID FID = SM.getFileID(ExpansionRange.getBegin());
1495 if (FID != SM.getFileID(ExpansionRange.getEnd()))
1499 const llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, &Invalid);
1503 unsigned BeginOffset = SM.getFileOffset(ExpansionRange.getBegin());
1504 unsigned EndOffset = SM.getFileOffset(ExpansionRange.getEnd());
1505 StringRef Snippet = Buffer->getBuffer().slice(BeginOffset, EndOffset);
1507 // We're searching the raw bytes of the buffer here, which might include
1508 // escaped newlines and such. That's okay; we're trying to decide whether the
1509 // SourceRange is covering a large or small amount of space in the user's
1511 if (Snippet.find_first_of("\r\n") != StringRef::npos)
1514 // This isn't Unicode-aware, but it doesn't need to be.
1515 return Snippet.size();
1518 /// \sa getLengthOnSingleLine(SourceManager, SourceRange)
1519 static Optional<size_t> getLengthOnSingleLine(SourceManager &SM,
1521 return getLengthOnSingleLine(SM, S->getSourceRange());
1524 /// Eliminate two-edge cycles created by addContextEdges().
1526 /// Once all the context edges are in place, there are plenty of cases where
1527 /// there's a single edge from a top-level statement to a subexpression,
1528 /// followed by a single path note, and then a reverse edge to get back out to
1529 /// the top level. If the statement is simple enough, the subexpression edges
1530 /// just add noise and make it harder to understand what's going on.
1532 /// This function only removes edges in pairs, because removing only one edge
1533 /// might leave other edges dangling.
1535 /// This will not remove edges in more complicated situations:
1536 /// - if there is more than one "hop" leading to or from a subexpression.
1537 /// - if there is an inlined call between the edges instead of a single event.
1538 /// - if the whole statement is large enough that having subexpression arrows
1539 /// might be helpful.
1540 static void removeContextCycles(PathPieces &Path, SourceManager &SM) {
1541 for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) {
1542 // Pattern match the current piece and its successor.
1543 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1550 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1551 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1553 PathPieces::iterator NextI = I; ++NextI;
1557 const auto *PieceNextI =
1558 dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1561 if (isa<PathDiagnosticEventPiece>(NextI->get())) {
1565 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1574 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1575 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1577 if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) {
1578 const size_t MAX_SHORT_LINE_LENGTH = 80;
1579 Optional<size_t> s1Length = getLengthOnSingleLine(SM, s1Start);
1580 if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) {
1581 Optional<size_t> s2Length = getLengthOnSingleLine(SM, s2Start);
1582 if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) {
1584 I = Path.erase(NextI);
1594 /// Return true if X is contained by Y.
1595 static bool lexicalContains(ParentMap &PM, const Stmt *X, const Stmt *Y) {
1599 X = PM.getParent(X);
1604 // Remove short edges on the same line less than 3 columns in difference.
1605 static void removePunyEdges(PathPieces &path, SourceManager &SM,
1607 bool erased = false;
1609 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E;
1613 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1618 const Stmt *start = PieceI->getStartLocation().getStmtOrNull();
1619 const Stmt *end = PieceI->getEndLocation().getStmtOrNull();
1624 const Stmt *endParent = PM.getParent(end);
1628 if (isConditionForTerminator(end, endParent))
1631 SourceLocation FirstLoc = start->getBeginLoc();
1632 SourceLocation SecondLoc = end->getBeginLoc();
1634 if (!SM.isWrittenInSameFile(FirstLoc, SecondLoc))
1636 if (SM.isBeforeInTranslationUnit(SecondLoc, FirstLoc))
1637 std::swap(SecondLoc, FirstLoc);
1639 SourceRange EdgeRange(FirstLoc, SecondLoc);
1640 Optional<size_t> ByteWidth = getLengthOnSingleLine(SM, EdgeRange);
1642 // If the statements are on different lines, continue.
1646 const size_t MAX_PUNY_EDGE_LENGTH = 2;
1647 if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) {
1648 // FIXME: There are enough /bytes/ between the endpoints of the edge, but
1649 // there might not be enough /columns/. A proper user-visible column count
1650 // is probably too expensive, though.
1658 static void removeIdenticalEvents(PathPieces &path) {
1659 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) {
1660 const auto *PieceI = dyn_cast<PathDiagnosticEventPiece>(I->get());
1665 PathPieces::iterator NextI = I; ++NextI;
1669 const auto *PieceNextI = dyn_cast<PathDiagnosticEventPiece>(NextI->get());
1674 // Erase the second piece if it has the same exact message text.
1675 if (PieceI->getString() == PieceNextI->getString()) {
1681 static bool optimizeEdges(PathPieces &path, SourceManager &SM,
1682 OptimizedCallsSet &OCS,
1683 LocationContextMap &LCM) {
1684 bool hasChanges = false;
1685 const LocationContext *LC = LCM[&path];
1687 ParentMap &PM = LC->getParentMap();
1689 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) {
1690 // Optimize subpaths.
1691 if (auto *CallI = dyn_cast<PathDiagnosticCallPiece>(I->get())) {
1692 // Record the fact that a call has been optimized so we only do the
1694 if (!OCS.count(CallI)) {
1695 while (optimizeEdges(CallI->path, SM, OCS, LCM)) {}
1702 // Pattern match the current piece and its successor.
1703 auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get());
1710 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull();
1711 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull();
1712 const Stmt *level1 = getStmtParent(s1Start, PM);
1713 const Stmt *level2 = getStmtParent(s1End, PM);
1715 PathPieces::iterator NextI = I; ++NextI;
1719 const auto *PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get());
1726 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull();
1727 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull();
1728 const Stmt *level3 = getStmtParent(s2Start, PM);
1729 const Stmt *level4 = getStmtParent(s2End, PM);
1733 // If we have two consecutive control edges whose end/begin locations
1734 // are at the same level (e.g. statements or top-level expressions within
1735 // a compound statement, or siblings share a single ancestor expression),
1736 // then merge them if they have no interesting intermediate event.
1740 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common
1741 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements.
1743 // NOTE: this will be limited later in cases where we add barriers
1744 // to prevent this optimization.
1745 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) {
1746 PieceI->setEndLocation(PieceNextI->getEndLocation());
1754 // Eliminate edges between subexpressions and parent expressions
1755 // when the subexpression is consumed.
1757 // NOTE: this will be limited later in cases where we add barriers
1758 // to prevent this optimization.
1759 if (s1End && s1End == s2Start && level2) {
1760 bool removeEdge = false;
1761 // Remove edges into the increment or initialization of a
1762 // loop that have no interleaving event. This means that
1763 // they aren't interesting.
1764 if (isIncrementOrInitInForLoop(s1End, level2))
1766 // Next only consider edges that are not anchored on
1767 // the condition of a terminator. This are intermediate edges
1768 // that we might want to trim.
1769 else if (!isConditionForTerminator(level2, s1End)) {
1770 // Trim edges on expressions that are consumed by
1771 // the parent expression.
1772 if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) {
1775 // Trim edges where a lexical containment doesn't exist.
1780 // If 'Z' lexically contains Y (it is an ancestor) and
1781 // 'X' does not lexically contain Y (it is a descendant OR
1782 // it has no lexical relationship at all) then trim.
1784 // This can eliminate edges where we dive into a subexpression
1785 // and then pop back out, etc.
1786 else if (s1Start && s2End &&
1787 lexicalContains(PM, s2Start, s2End) &&
1788 !lexicalContains(PM, s1End, s1Start)) {
1791 // Trim edges from a subexpression back to the top level if the
1792 // subexpression is on a different line.
1798 // These edges just look ugly and don't usually add anything.
1799 else if (s1Start && s2End &&
1800 lexicalContains(PM, s1Start, s1End)) {
1801 SourceRange EdgeRange(PieceI->getEndLocation().asLocation(),
1802 PieceI->getStartLocation().asLocation());
1803 if (!getLengthOnSingleLine(SM, EdgeRange).hasValue())
1809 PieceI->setEndLocation(PieceNextI->getEndLocation());
1816 // Optimize edges for ObjC fast-enumeration loops.
1818 // (X -> collection) -> (collection -> element)
1823 if (s1End == s2Start) {
1824 const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(level3);
1825 if (FS && FS->getCollection()->IgnoreParens() == s2Start &&
1826 s2End == FS->getElement()) {
1827 PieceI->setEndLocation(PieceNextI->getEndLocation());
1834 // No changes at this index? Move to the next one.
1839 // Adjust edges into subexpressions to make them more uniform
1840 // and aesthetically pleasing.
1841 addContextEdges(path, SM, PM, LC);
1842 // Remove "cyclical" edges that include one or more context edges.
1843 removeContextCycles(path, SM);
1844 // Hoist edges originating from branch conditions to branches
1845 // for simple branches.
1846 simplifySimpleBranches(path);
1847 // Remove any puny edges left over after primary optimization pass.
1848 removePunyEdges(path, SM, PM);
1849 // Remove identical events.
1850 removeIdenticalEvents(path);
1856 /// Drop the very first edge in a path, which should be a function entry edge.
1858 /// If the first edge is not a function entry edge (say, because the first
1859 /// statement had an invalid source location), this function does nothing.
1860 // FIXME: We should just generate invalid edges anyway and have the optimizer
1862 static void dropFunctionEntryEdge(PathPieces &Path, LocationContextMap &LCM,
1863 SourceManager &SM) {
1864 const auto *FirstEdge =
1865 dyn_cast<PathDiagnosticControlFlowPiece>(Path.front().get());
1869 const Decl *D = LCM[&Path]->getDecl();
1870 PathDiagnosticLocation EntryLoc = PathDiagnosticLocation::createBegin(D, SM);
1871 if (FirstEdge->getStartLocation() != EntryLoc)
1877 using VisitorsDiagnosticsTy = llvm::DenseMap<const ExplodedNode *,
1878 std::vector<std::shared_ptr<PathDiagnosticPiece>>>;
1880 /// Populate executes lines with lines containing at least one diagnostics.
1881 static void updateExecutedLinesWithDiagnosticPieces(
1882 PathDiagnostic &PD) {
1884 PathPieces path = PD.path.flatten(/*ShouldFlattenMacros=*/true);
1885 FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines();
1887 for (const auto &P : path) {
1888 FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc();
1889 FileID FID = Loc.getFileID();
1890 unsigned LineNo = Loc.getLineNumber();
1891 assert(FID.isValid());
1892 ExecutedLines[FID].insert(LineNo);
1896 /// This function is responsible for generating diagnostic pieces that are
1897 /// *not* provided by bug report visitors.
1898 /// These diagnostics may differ depending on the consumer's settings,
1899 /// and are therefore constructed separately for each consumer.
1901 /// There are two path diagnostics generation modes: with adding edges (used
1902 /// for plists) and without (used for HTML and text).
1903 /// When edges are added (\p ActiveScheme is Extensive),
1904 /// the path is modified to insert artificially generated
1906 /// Otherwise, more detailed diagnostics is emitted for block edges, explaining
1907 /// the transitions in words.
1908 static std::unique_ptr<PathDiagnostic> generatePathDiagnosticForConsumer(
1909 PathDiagnosticConsumer::PathGenerationScheme ActiveScheme,
1910 PathDiagnosticBuilder &PDB,
1911 const ExplodedNode *ErrorNode,
1912 const VisitorsDiagnosticsTy &VisitorsDiagnostics) {
1914 bool GenerateDiagnostics = (ActiveScheme != PathDiagnosticConsumer::None);
1915 bool AddPathEdges = (ActiveScheme == PathDiagnosticConsumer::Extensive);
1916 SourceManager &SM = PDB.getSourceManager();
1917 BugReport *R = PDB.getBugReport();
1918 AnalyzerOptions &Opts = PDB.getBugReporter().getAnalyzerOptions();
1919 StackDiagVector CallStack;
1920 InterestingExprs IE;
1921 LocationContextMap LCM;
1922 std::unique_ptr<PathDiagnostic> PD = generateEmptyDiagnosticForReport(R, SM);
1924 if (GenerateDiagnostics) {
1925 auto EndNotes = VisitorsDiagnostics.find(ErrorNode);
1926 std::shared_ptr<PathDiagnosticPiece> LastPiece;
1927 if (EndNotes != VisitorsDiagnostics.end()) {
1928 assert(!EndNotes->second.empty());
1929 LastPiece = EndNotes->second[0];
1931 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, ErrorNode, *R);
1933 PD->setEndOfPath(LastPiece);
1936 PathDiagnosticLocation PrevLoc = PD->getLocation();
1937 const ExplodedNode *NextNode = ErrorNode->getFirstPred();
1939 if (GenerateDiagnostics)
1940 generatePathDiagnosticsForNode(
1941 NextNode, *PD, PrevLoc, PDB, LCM, CallStack, IE, AddPathEdges);
1943 auto VisitorNotes = VisitorsDiagnostics.find(NextNode);
1944 NextNode = NextNode->getFirstPred();
1945 if (!GenerateDiagnostics || VisitorNotes == VisitorsDiagnostics.end())
1948 // This is a workaround due to inability to put shared PathDiagnosticPiece
1949 // into a FoldingSet.
1950 std::set<llvm::FoldingSetNodeID> DeduplicationSet;
1952 // Add pieces from custom visitors.
1953 for (const auto &Note : VisitorNotes->second) {
1954 llvm::FoldingSetNodeID ID;
1956 auto P = DeduplicationSet.insert(ID);
1961 addEdgeToPath(PD->getActivePath(), PrevLoc, Note->getLocation());
1962 updateStackPiecesWithMessage(*Note, CallStack);
1963 PD->getActivePath().push_front(Note);
1968 // Add an edge to the start of the function.
1969 // We'll prune it out later, but it helps make diagnostics more uniform.
1970 const StackFrameContext *CalleeLC = PDB.LC->getStackFrame();
1971 const Decl *D = CalleeLC->getDecl();
1972 addEdgeToPath(PD->getActivePath(), PrevLoc,
1973 PathDiagnosticLocation::createBegin(D, SM));
1977 // Finally, prune the diagnostic path of uninteresting stuff.
1978 if (!PD->path.empty()) {
1979 if (R->shouldPrunePath() && Opts.ShouldPrunePaths) {
1980 bool stillHasNotes =
1981 removeUnneededCalls(PD->getMutablePieces(), R, LCM);
1982 assert(stillHasNotes);
1983 (void)stillHasNotes;
1986 // Redirect all call pieces to have valid locations.
1987 adjustCallLocations(PD->getMutablePieces());
1988 removePiecesWithInvalidLocations(PD->getMutablePieces());
1992 // Reduce the number of edges from a very conservative set
1993 // to an aesthetically pleasing subset that conveys the
1994 // necessary information.
1995 OptimizedCallsSet OCS;
1996 while (optimizeEdges(PD->getMutablePieces(), SM, OCS, LCM)) {}
1998 // Drop the very first function-entry edge. It's not really necessary
1999 // for top-level functions.
2000 dropFunctionEntryEdge(PD->getMutablePieces(), LCM, SM);
2003 // Remove messages that are basically the same, and edges that may not
2005 // We have to do this after edge optimization in the Extensive mode.
2006 removeRedundantMsgs(PD->getMutablePieces());
2007 removeEdgesToDefaultInitializers(PD->getMutablePieces());
2010 if (GenerateDiagnostics && Opts.ShouldDisplayMacroExpansions)
2011 CompactMacroExpandedPieces(PD->getMutablePieces(), SM);
2017 //===----------------------------------------------------------------------===//
2018 // Methods for BugType and subclasses.
2019 //===----------------------------------------------------------------------===//
2021 void BugType::anchor() {}
2023 void BuiltinBug::anchor() {}
2025 //===----------------------------------------------------------------------===//
2026 // Methods for BugReport and subclasses.
2027 //===----------------------------------------------------------------------===//
2029 void BugReport::NodeResolver::anchor() {}
2031 void BugReport::addVisitor(std::unique_ptr<BugReporterVisitor> visitor) {
2035 llvm::FoldingSetNodeID ID;
2036 visitor->Profile(ID);
2038 void *InsertPos = nullptr;
2039 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) {
2043 Callbacks.push_back(std::move(visitor));
2046 void BugReport::clearVisitors() {
2050 BugReport::~BugReport() {
2051 while (!interestingSymbols.empty()) {
2052 popInterestingSymbolsAndRegions();
2056 const Decl *BugReport::getDeclWithIssue() const {
2058 return DeclWithIssue;
2060 const ExplodedNode *N = getErrorNode();
2064 const LocationContext *LC = N->getLocationContext();
2065 return LC->getStackFrame()->getDecl();
2068 void BugReport::Profile(llvm::FoldingSetNodeID& hash) const {
2069 hash.AddPointer(&BT);
2070 hash.AddString(Description);
2071 PathDiagnosticLocation UL = getUniqueingLocation();
2074 } else if (Location.isValid()) {
2075 Location.Profile(hash);
2078 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode));
2081 for (SourceRange range : Ranges) {
2082 if (!range.isValid())
2084 hash.AddInteger(range.getBegin().getRawEncoding());
2085 hash.AddInteger(range.getEnd().getRawEncoding());
2089 void BugReport::markInteresting(SymbolRef sym) {
2093 getInterestingSymbols().insert(sym);
2095 if (const auto *meta = dyn_cast<SymbolMetadata>(sym))
2096 getInterestingRegions().insert(meta->getRegion());
2099 void BugReport::markInteresting(const MemRegion *R) {
2103 R = R->getBaseRegion();
2104 getInterestingRegions().insert(R);
2106 if (const auto *SR = dyn_cast<SymbolicRegion>(R))
2107 getInterestingSymbols().insert(SR->getSymbol());
2110 void BugReport::markInteresting(SVal V) {
2111 markInteresting(V.getAsRegion());
2112 markInteresting(V.getAsSymbol());
2115 void BugReport::markInteresting(const LocationContext *LC) {
2118 InterestingLocationContexts.insert(LC);
2121 bool BugReport::isInteresting(SVal V) {
2122 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol());
2125 bool BugReport::isInteresting(SymbolRef sym) {
2128 // We don't currently consider metadata symbols to be interesting
2129 // even if we know their region is interesting. Is that correct behavior?
2130 return getInterestingSymbols().count(sym);
2133 bool BugReport::isInteresting(const MemRegion *R) {
2136 R = R->getBaseRegion();
2137 bool b = getInterestingRegions().count(R);
2140 if (const auto *SR = dyn_cast<SymbolicRegion>(R))
2141 return getInterestingSymbols().count(SR->getSymbol());
2145 bool BugReport::isInteresting(const LocationContext *LC) {
2148 return InterestingLocationContexts.count(LC);
2151 void BugReport::lazyInitializeInterestingSets() {
2152 if (interestingSymbols.empty()) {
2153 interestingSymbols.push_back(new Symbols());
2154 interestingRegions.push_back(new Regions());
2158 BugReport::Symbols &BugReport::getInterestingSymbols() {
2159 lazyInitializeInterestingSets();
2160 return *interestingSymbols.back();
2163 BugReport::Regions &BugReport::getInterestingRegions() {
2164 lazyInitializeInterestingSets();
2165 return *interestingRegions.back();
2168 void BugReport::pushInterestingSymbolsAndRegions() {
2169 interestingSymbols.push_back(new Symbols(getInterestingSymbols()));
2170 interestingRegions.push_back(new Regions(getInterestingRegions()));
2173 void BugReport::popInterestingSymbolsAndRegions() {
2174 delete interestingSymbols.pop_back_val();
2175 delete interestingRegions.pop_back_val();
2178 const Stmt *BugReport::getStmt() const {
2182 ProgramPoint ProgP = ErrorNode->getLocation();
2183 const Stmt *S = nullptr;
2185 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) {
2186 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit();
2187 if (BE->getBlock() == &Exit)
2188 S = GetPreviousStmt(ErrorNode);
2191 S = PathDiagnosticLocation::getStmt(ErrorNode);
2196 llvm::iterator_range<BugReport::ranges_iterator> BugReport::getRanges() {
2197 // If no custom ranges, add the range of the statement corresponding to
2199 if (Ranges.empty()) {
2200 if (const auto *E = dyn_cast_or_null<Expr>(getStmt()))
2201 addRange(E->getSourceRange());
2203 return llvm::make_range(ranges_iterator(), ranges_iterator());
2206 // User-specified absence of range info.
2207 if (Ranges.size() == 1 && !Ranges.begin()->isValid())
2208 return llvm::make_range(ranges_iterator(), ranges_iterator());
2210 return llvm::make_range(Ranges.begin(), Ranges.end());
2213 PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const {
2215 assert(!Location.isValid() &&
2216 "Either Location or ErrorNode should be specified but not both.");
2217 return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM);
2220 assert(Location.isValid());
2224 //===----------------------------------------------------------------------===//
2225 // Methods for BugReporter and subclasses.
2226 //===----------------------------------------------------------------------===//
2228 BugReportEquivClass::~BugReportEquivClass() = default;
2230 GRBugReporter::~GRBugReporter() = default;
2232 BugReporterData::~BugReporterData() = default;
2234 ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); }
2236 ProgramStateManager&
2237 GRBugReporter::getStateManager() { return Eng.getStateManager(); }
2239 BugReporter::~BugReporter() {
2242 // Free the bug reports we are tracking.
2243 for (const auto I : EQClassesVector)
2247 void BugReporter::FlushReports() {
2248 if (BugTypes.isEmpty())
2251 // We need to flush reports in deterministic order to ensure the order
2252 // of the reports is consistent between runs.
2253 for (const auto EQ : EQClassesVector)
2256 // BugReporter owns and deletes only BugTypes created implicitly through
2258 // FIXME: There are leaks from checkers that assume that the BugTypes they
2259 // create will be destroyed by the BugReporter.
2260 llvm::DeleteContainerSeconds(StrBugTypes);
2262 // Remove all references to the BugType objects.
2263 BugTypes = F.getEmptySet();
2266 //===----------------------------------------------------------------------===//
2267 // PathDiagnostics generation.
2268 //===----------------------------------------------------------------------===//
2272 /// A wrapper around a report graph, which contains only a single path, and its
2276 InterExplodedGraphMap BackMap;
2277 std::unique_ptr<ExplodedGraph> Graph;
2278 const ExplodedNode *ErrorNode;
2282 /// A wrapper around a trimmed graph and its node maps.
2283 class TrimmedGraph {
2284 InterExplodedGraphMap InverseMap;
2286 using PriorityMapTy = llvm::DenseMap<const ExplodedNode *, unsigned>;
2288 PriorityMapTy PriorityMap;
2290 using NodeIndexPair = std::pair<const ExplodedNode *, size_t>;
2292 SmallVector<NodeIndexPair, 32> ReportNodes;
2294 std::unique_ptr<ExplodedGraph> G;
2296 /// A helper class for sorting ExplodedNodes by priority.
2297 template <bool Descending>
2298 class PriorityCompare {
2299 const PriorityMapTy &PriorityMap;
2302 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {}
2304 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const {
2305 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS);
2306 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS);
2307 PriorityMapTy::const_iterator E = PriorityMap.end();
2314 return Descending ? LI->second > RI->second
2315 : LI->second < RI->second;
2318 bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const {
2319 return (*this)(LHS.first, RHS.first);
2324 TrimmedGraph(const ExplodedGraph *OriginalGraph,
2325 ArrayRef<const ExplodedNode *> Nodes);
2327 bool popNextReportGraph(ReportGraph &GraphWrapper);
2332 TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph,
2333 ArrayRef<const ExplodedNode *> Nodes) {
2334 // The trimmed graph is created in the body of the constructor to ensure
2335 // that the DenseMaps have been initialized already.
2336 InterExplodedGraphMap ForwardMap;
2337 G = OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap);
2339 // Find the (first) error node in the trimmed graph. We just need to consult
2340 // the node map which maps from nodes in the original graph to nodes
2341 // in the new graph.
2342 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes;
2344 for (unsigned i = 0, count = Nodes.size(); i < count; ++i) {
2345 if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) {
2346 ReportNodes.push_back(std::make_pair(NewNode, i));
2347 RemainingNodes.insert(NewNode);
2351 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph");
2353 // Perform a forward BFS to find all the shortest paths.
2354 std::queue<const ExplodedNode *> WS;
2356 assert(G->num_roots() == 1);
2357 WS.push(*G->roots_begin());
2358 unsigned Priority = 0;
2360 while (!WS.empty()) {
2361 const ExplodedNode *Node = WS.front();
2364 PriorityMapTy::iterator PriorityEntry;
2366 std::tie(PriorityEntry, IsNew) =
2367 PriorityMap.insert(std::make_pair(Node, Priority));
2371 assert(PriorityEntry->second <= Priority);
2375 if (RemainingNodes.erase(Node))
2376 if (RemainingNodes.empty())
2379 for (ExplodedNode::const_pred_iterator I = Node->succ_begin(),
2380 E = Node->succ_end();
2385 // Sort the error paths from longest to shortest.
2386 llvm::sort(ReportNodes, PriorityCompare<true>(PriorityMap));
2389 bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) {
2390 if (ReportNodes.empty())
2393 const ExplodedNode *OrigN;
2394 std::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val();
2395 assert(PriorityMap.find(OrigN) != PriorityMap.end() &&
2396 "error node not accessible from root");
2398 // Create a new graph with a single path. This is the graph
2399 // that will be returned to the caller.
2400 auto GNew = llvm::make_unique<ExplodedGraph>();
2401 GraphWrapper.BackMap.clear();
2403 // Now walk from the error node up the BFS path, always taking the
2404 // predeccessor with the lowest number.
2405 ExplodedNode *Succ = nullptr;
2407 // Create the equivalent node in the new graph with the same state
2409 ExplodedNode *NewN = GNew->createUncachedNode(OrigN->getLocation(), OrigN->getState(),
2412 // Store the mapping to the original node.
2413 InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN);
2414 assert(IMitr != InverseMap.end() && "No mapping to original node.");
2415 GraphWrapper.BackMap[NewN] = IMitr->second;
2417 // Link up the new node with the previous node.
2419 Succ->addPredecessor(NewN, *GNew);
2421 GraphWrapper.ErrorNode = NewN;
2425 // Are we at the final node?
2426 if (OrigN->pred_empty()) {
2427 GNew->addRoot(NewN);
2431 // Find the next predeccessor node. We choose the node that is marked
2432 // with the lowest BFS number.
2433 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(),
2434 PriorityCompare<false>(PriorityMap));
2437 GraphWrapper.Graph = std::move(GNew);
2442 /// CompactMacroExpandedPieces - This function postprocesses a PathDiagnostic
2443 /// object and collapses PathDiagosticPieces that are expanded by macros.
2444 static void CompactMacroExpandedPieces(PathPieces &path,
2445 const SourceManager& SM) {
2446 using MacroStackTy =
2448 std::pair<std::shared_ptr<PathDiagnosticMacroPiece>, SourceLocation>>;
2450 using PiecesTy = std::vector<std::shared_ptr<PathDiagnosticPiece>>;
2452 MacroStackTy MacroStack;
2455 for (PathPieces::const_iterator I = path.begin(), E = path.end();
2457 const auto &piece = *I;
2459 // Recursively compact calls.
2460 if (auto *call = dyn_cast<PathDiagnosticCallPiece>(&*piece)) {
2461 CompactMacroExpandedPieces(call->path, SM);
2464 // Get the location of the PathDiagnosticPiece.
2465 const FullSourceLoc Loc = piece->getLocation().asLocation();
2467 // Determine the instantiation location, which is the location we group
2468 // related PathDiagnosticPieces.
2469 SourceLocation InstantiationLoc = Loc.isMacroID() ?
2470 SM.getExpansionLoc(Loc) :
2473 if (Loc.isFileID()) {
2475 Pieces.push_back(piece);
2479 assert(Loc.isMacroID());
2481 // Is the PathDiagnosticPiece within the same macro group?
2482 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) {
2483 MacroStack.back().first->subPieces.push_back(piece);
2487 // We aren't in the same group. Are we descending into a new macro
2488 // or are part of an old one?
2489 std::shared_ptr<PathDiagnosticMacroPiece> MacroGroup;
2491 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ?
2492 SM.getExpansionLoc(Loc) :
2495 // Walk the entire macro stack.
2496 while (!MacroStack.empty()) {
2497 if (InstantiationLoc == MacroStack.back().second) {
2498 MacroGroup = MacroStack.back().first;
2502 if (ParentInstantiationLoc == MacroStack.back().second) {
2503 MacroGroup = MacroStack.back().first;
2507 MacroStack.pop_back();
2510 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) {
2511 // Create a new macro group and add it to the stack.
2512 auto NewGroup = std::make_shared<PathDiagnosticMacroPiece>(
2513 PathDiagnosticLocation::createSingleLocation(piece->getLocation()));
2516 MacroGroup->subPieces.push_back(NewGroup);
2518 assert(InstantiationLoc.isFileID());
2519 Pieces.push_back(NewGroup);
2522 MacroGroup = NewGroup;
2523 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc));
2526 // Finally, add the PathDiagnosticPiece to the group.
2527 MacroGroup->subPieces.push_back(piece);
2530 // Now take the pieces and construct a new PathDiagnostic.
2533 path.insert(path.end(), Pieces.begin(), Pieces.end());
2536 /// Generate notes from all visitors.
2537 /// Notes associated with {@code ErrorNode} are generated using
2538 /// {@code getEndPath}, and the rest are generated with {@code VisitNode}.
2539 static std::unique_ptr<VisitorsDiagnosticsTy>
2540 generateVisitorsDiagnostics(BugReport *R, const ExplodedNode *ErrorNode,
2541 BugReporterContext &BRC) {
2542 auto Notes = llvm::make_unique<VisitorsDiagnosticsTy>();
2543 BugReport::VisitorList visitors;
2545 // Run visitors on all nodes starting from the node *before* the last one.
2546 // The last node is reserved for notes generated with {@code getEndPath}.
2547 const ExplodedNode *NextNode = ErrorNode->getFirstPred();
2550 // At each iteration, move all visitors from report to visitor list.
2551 for (BugReport::visitor_iterator I = R->visitor_begin(),
2552 E = R->visitor_end();
2554 visitors.push_back(std::move(*I));
2558 const ExplodedNode *Pred = NextNode->getFirstPred();
2560 std::shared_ptr<PathDiagnosticPiece> LastPiece;
2561 for (auto &V : visitors) {
2562 V->finalizeVisitor(BRC, ErrorNode, *R);
2564 if (auto Piece = V->getEndPath(BRC, ErrorNode, *R)) {
2565 assert(!LastPiece &&
2566 "There can only be one final piece in a diagnostic.");
2567 LastPiece = std::move(Piece);
2568 (*Notes)[ErrorNode].push_back(LastPiece);
2574 for (auto &V : visitors) {
2575 auto P = V->VisitNode(NextNode, BRC, *R);
2577 (*Notes)[NextNode].push_back(std::move(P));
2589 /// Find a non-invalidated report for a given equivalence class,
2590 /// and return together with a cache of visitors notes.
2591 /// If none found, return a nullptr paired with an empty cache.
2593 std::pair<BugReport*, std::unique_ptr<VisitorsDiagnosticsTy>> findValidReport(
2594 TrimmedGraph &TrimG,
2595 ReportGraph &ErrorGraph,
2596 ArrayRef<BugReport *> &bugReports,
2597 AnalyzerOptions &Opts,
2598 GRBugReporter &Reporter) {
2600 while (TrimG.popNextReportGraph(ErrorGraph)) {
2601 // Find the BugReport with the original location.
2602 assert(ErrorGraph.Index < bugReports.size());
2603 BugReport *R = bugReports[ErrorGraph.Index];
2604 assert(R && "No original report found for sliced graph.");
2605 assert(R->isValid() && "Report selected by trimmed graph marked invalid.");
2606 const ExplodedNode *ErrorNode = ErrorGraph.ErrorNode;
2608 // Register refutation visitors first, if they mark the bug invalid no
2609 // further analysis is required
2610 R->addVisitor(llvm::make_unique<LikelyFalsePositiveSuppressionBRVisitor>());
2612 // Register additional node visitors.
2613 R->addVisitor(llvm::make_unique<NilReceiverBRVisitor>());
2614 R->addVisitor(llvm::make_unique<ConditionBRVisitor>());
2615 R->addVisitor(llvm::make_unique<CXXSelfAssignmentBRVisitor>());
2617 BugReporterContext BRC(Reporter, ErrorGraph.BackMap);
2619 // Run all visitors on a given graph, once.
2620 std::unique_ptr<VisitorsDiagnosticsTy> visitorNotes =
2621 generateVisitorsDiagnostics(R, ErrorNode, BRC);
2624 if (Opts.ShouldCrosscheckWithZ3) {
2625 // If crosscheck is enabled, remove all visitors, add the refutation
2626 // visitor and check again
2628 R->addVisitor(llvm::make_unique<FalsePositiveRefutationBRVisitor>());
2630 // We don't overrite the notes inserted by other visitors because the
2631 // refutation manager does not add any new note to the path
2632 generateVisitorsDiagnostics(R, ErrorGraph.ErrorNode, BRC);
2635 // Check if the bug is still valid
2637 return std::make_pair(R, std::move(visitorNotes));
2641 return std::make_pair(nullptr, llvm::make_unique<VisitorsDiagnosticsTy>());
2644 std::unique_ptr<DiagnosticForConsumerMapTy>
2645 GRBugReporter::generatePathDiagnostics(
2646 ArrayRef<PathDiagnosticConsumer *> consumers,
2647 ArrayRef<BugReport *> &bugReports) {
2648 assert(!bugReports.empty());
2650 auto Out = llvm::make_unique<DiagnosticForConsumerMapTy>();
2651 bool HasValid = false;
2652 SmallVector<const ExplodedNode *, 32> errorNodes;
2653 for (const auto I : bugReports) {
2656 errorNodes.push_back(I->getErrorNode());
2658 // Keep the errorNodes list in sync with the bugReports list.
2659 errorNodes.push_back(nullptr);
2663 // If all the reports have been marked invalid by a previous path generation,
2668 TrimmedGraph TrimG(&getGraph(), errorNodes);
2669 ReportGraph ErrorGraph;
2670 auto ReportInfo = findValidReport(TrimG, ErrorGraph, bugReports,
2671 getAnalyzerOptions(), *this);
2672 BugReport *R = ReportInfo.first;
2674 if (R && R->isValid()) {
2675 const ExplodedNode *ErrorNode = ErrorGraph.ErrorNode;
2676 for (PathDiagnosticConsumer *PC : consumers) {
2677 PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, PC);
2678 std::unique_ptr<PathDiagnostic> PD = generatePathDiagnosticForConsumer(
2679 PC->getGenerationScheme(), PDB, ErrorNode, *ReportInfo.second);
2680 (*Out)[PC] = std::move(PD);
2687 void BugReporter::Register(BugType *BT) {
2688 BugTypes = F.add(BugTypes, BT);
2691 void BugReporter::emitReport(std::unique_ptr<BugReport> R) {
2692 if (const ExplodedNode *E = R->getErrorNode()) {
2693 // An error node must either be a sink or have a tag, otherwise
2694 // it could get reclaimed before the path diagnostic is created.
2695 assert((E->isSink() || E->getLocation().getTag()) &&
2696 "Error node must either be a sink or have a tag");
2698 const AnalysisDeclContext *DeclCtx =
2699 E->getLocationContext()->getAnalysisDeclContext();
2700 // The source of autosynthesized body can be handcrafted AST or a model
2701 // file. The locations from handcrafted ASTs have no valid source locations
2702 // and have to be discarded. Locations from model files should be preserved
2703 // for processing and reporting.
2704 if (DeclCtx->isBodyAutosynthesized() &&
2705 !DeclCtx->isBodyAutosynthesizedFromModelFile())
2709 bool ValidSourceLoc = R->getLocation(getSourceManager()).isValid();
2710 assert(ValidSourceLoc);
2711 // If we mess up in a release build, we'd still prefer to just drop the bug
2712 // instead of trying to go on.
2713 if (!ValidSourceLoc)
2716 // Compute the bug report's hash to determine its equivalence class.
2717 llvm::FoldingSetNodeID ID;
2720 // Lookup the equivance class. If there isn't one, create it.
2721 BugType& BT = R->getBugType();
2724 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos);
2727 EQ = new BugReportEquivClass(std::move(R));
2728 EQClasses.InsertNode(EQ, InsertPos);
2729 EQClassesVector.push_back(EQ);
2731 EQ->AddReport(std::move(R));
2734 //===----------------------------------------------------------------------===//
2735 // Emitting reports in equivalence classes.
2736 //===----------------------------------------------------------------------===//
2740 struct FRIEC_WLItem {
2741 const ExplodedNode *N;
2742 ExplodedNode::const_succ_iterator I, E;
2744 FRIEC_WLItem(const ExplodedNode *n)
2745 : N(n), I(N->succ_begin()), E(N->succ_end()) {}
2750 static const CFGBlock *findBlockForNode(const ExplodedNode *N) {
2751 ProgramPoint P = N->getLocation();
2752 if (auto BEP = P.getAs<BlockEntrance>())
2753 return BEP->getBlock();
2755 // Find the node's current statement in the CFG.
2756 if (const Stmt *S = PathDiagnosticLocation::getStmt(N))
2757 return N->getLocationContext()->getAnalysisDeclContext()
2758 ->getCFGStmtMap()->getBlock(S);
2763 // Returns true if by simply looking at the block, we can be sure that it
2764 // results in a sink during analysis. This is useful to know when the analysis
2765 // was interrupted, and we try to figure out if it would sink eventually.
2766 // There may be many more reasons why a sink would appear during analysis
2767 // (eg. checkers may generate sinks arbitrarily), but here we only consider
2768 // sinks that would be obvious by looking at the CFG.
2769 static bool isImmediateSinkBlock(const CFGBlock *Blk) {
2770 if (Blk->hasNoReturnElement())
2773 // FIXME: Throw-expressions are currently generating sinks during analysis:
2774 // they're not supported yet, and also often used for actually terminating
2775 // the program. So we should treat them as sinks in this analysis as well,
2776 // at least for now, but once we have better support for exceptions,
2777 // we'd need to carefully handle the case when the throw is being
2778 // immediately caught.
2779 if (std::any_of(Blk->begin(), Blk->end(), [](const CFGElement &Elm) {
2780 if (Optional<CFGStmt> StmtElm = Elm.getAs<CFGStmt>())
2781 if (isa<CXXThrowExpr>(StmtElm->getStmt()))
2790 // Returns true if by looking at the CFG surrounding the node's program
2791 // point, we can be sure that any analysis starting from this point would
2792 // eventually end with a sink. We scan the child CFG blocks in a depth-first
2793 // manner and see if all paths eventually end up in an immediate sink block.
2794 static bool isInevitablySinking(const ExplodedNode *N) {
2795 const CFG &Cfg = N->getCFG();
2797 const CFGBlock *StartBlk = findBlockForNode(N);
2800 if (isImmediateSinkBlock(StartBlk))
2803 llvm::SmallVector<const CFGBlock *, 32> DFSWorkList;
2804 llvm::SmallPtrSet<const CFGBlock *, 32> Visited;
2806 DFSWorkList.push_back(StartBlk);
2807 while (!DFSWorkList.empty()) {
2808 const CFGBlock *Blk = DFSWorkList.back();
2809 DFSWorkList.pop_back();
2810 Visited.insert(Blk);
2812 // If at least one path reaches the CFG exit, it means that control is
2813 // returned to the caller. For now, say that we are not sure what
2814 // happens next. If necessary, this can be improved to analyze
2815 // the parent StackFrameContext's call site in a similar manner.
2816 if (Blk == &Cfg.getExit())
2819 for (const auto &Succ : Blk->succs()) {
2820 if (const CFGBlock *SuccBlk = Succ.getReachableBlock()) {
2821 if (!isImmediateSinkBlock(SuccBlk) && !Visited.count(SuccBlk)) {
2822 // If the block has reachable child blocks that aren't no-return,
2823 // add them to the worklist.
2824 DFSWorkList.push_back(SuccBlk);
2830 // Nothing reached the exit. It can only mean one thing: there's no return.
2835 FindReportInEquivalenceClass(BugReportEquivClass& EQ,
2836 SmallVectorImpl<BugReport*> &bugReports) {
2837 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end();
2839 BugType& BT = I->getBugType();
2841 // If we don't need to suppress any of the nodes because they are
2842 // post-dominated by a sink, simply add all the nodes in the equivalence class
2843 // to 'Nodes'. Any of the reports will serve as a "representative" report.
2844 if (!BT.isSuppressOnSink()) {
2846 for (auto &I : EQ) {
2847 const ExplodedNode *N = I.getErrorNode();
2850 bugReports.push_back(R);
2856 // For bug reports that should be suppressed when all paths are post-dominated
2857 // by a sink node, iterate through the reports in the equivalence class
2858 // until we find one that isn't post-dominated (if one exists). We use a
2859 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write
2860 // this as a recursive function, but we don't want to risk blowing out the
2861 // stack for very long paths.
2862 BugReport *exampleReport = nullptr;
2864 for (; I != E; ++I) {
2865 const ExplodedNode *errorNode = I->getErrorNode();
2869 if (errorNode->isSink()) {
2871 "BugType::isSuppressSink() should not be 'true' for sink end nodes");
2873 // No successors? By definition this nodes isn't post-dominated by a sink.
2874 if (errorNode->succ_empty()) {
2875 bugReports.push_back(&*I);
2877 exampleReport = &*I;
2881 // See if we are in a no-return CFG block. If so, treat this similarly
2882 // to being post-dominated by a sink. This works better when the analysis
2883 // is incomplete and we have never reached the no-return function call(s)
2884 // that we'd inevitably bump into on this path.
2885 if (isInevitablySinking(errorNode))
2888 // At this point we know that 'N' is not a sink and it has at least one
2889 // successor. Use a DFS worklist to find a non-sink end-of-path node.
2890 using WLItem = FRIEC_WLItem;
2891 using DFSWorkList = SmallVector<WLItem, 10>;
2893 llvm::DenseMap<const ExplodedNode *, unsigned> Visited;
2896 WL.push_back(errorNode);
2897 Visited[errorNode] = 1;
2899 while (!WL.empty()) {
2900 WLItem &WI = WL.back();
2901 assert(!WI.N->succ_empty());
2903 for (; WI.I != WI.E; ++WI.I) {
2904 const ExplodedNode *Succ = *WI.I;
2905 // End-of-path node?
2906 if (Succ->succ_empty()) {
2907 // If we found an end-of-path node that is not a sink.
2908 if (!Succ->isSink()) {
2909 bugReports.push_back(&*I);
2911 exampleReport = &*I;
2915 // Found a sink? Continue on to the next successor.
2918 // Mark the successor as visited. If it hasn't been explored,
2919 // enqueue it to the DFS worklist.
2920 unsigned &mark = Visited[Succ];
2928 // The worklist may have been cleared at this point. First
2929 // check if it is empty before checking the last item.
2930 if (!WL.empty() && &WL.back() == &WI)
2935 // ExampleReport will be NULL if all the nodes in the equivalence class
2936 // were post-dominated by sinks.
2937 return exampleReport;
2940 void BugReporter::FlushReport(BugReportEquivClass& EQ) {
2941 SmallVector<BugReport*, 10> bugReports;
2942 BugReport *report = FindReportInEquivalenceClass(EQ, bugReports);
2946 ArrayRef<PathDiagnosticConsumer*> Consumers = getPathDiagnosticConsumers();
2947 std::unique_ptr<DiagnosticForConsumerMapTy> Diagnostics =
2948 generateDiagnosticForConsumerMap(report, Consumers, bugReports);
2950 for (auto &P : *Diagnostics) {
2951 PathDiagnosticConsumer *Consumer = P.first;
2952 std::unique_ptr<PathDiagnostic> &PD = P.second;
2954 // If the path is empty, generate a single step path with the location
2956 if (PD->path.empty()) {
2957 PathDiagnosticLocation L = report->getLocation(getSourceManager());
2958 auto piece = llvm::make_unique<PathDiagnosticEventPiece>(
2959 L, report->getDescription());
2960 for (SourceRange Range : report->getRanges())
2961 piece->addRange(Range);
2962 PD->setEndOfPath(std::move(piece));
2965 PathPieces &Pieces = PD->getMutablePieces();
2966 if (getAnalyzerOptions().ShouldDisplayNotesAsEvents) {
2967 // For path diagnostic consumers that don't support extra notes,
2968 // we may optionally convert those to path notes.
2969 for (auto I = report->getNotes().rbegin(),
2970 E = report->getNotes().rend(); I != E; ++I) {
2971 PathDiagnosticNotePiece *Piece = I->get();
2972 auto ConvertedPiece = std::make_shared<PathDiagnosticEventPiece>(
2973 Piece->getLocation(), Piece->getString());
2974 for (const auto &R: Piece->getRanges())
2975 ConvertedPiece->addRange(R);
2977 Pieces.push_front(std::move(ConvertedPiece));
2980 for (auto I = report->getNotes().rbegin(),
2981 E = report->getNotes().rend(); I != E; ++I)
2982 Pieces.push_front(*I);
2985 // Get the meta data.
2986 const BugReport::ExtraTextList &Meta = report->getExtraText();
2987 for (const auto &i : Meta)
2990 updateExecutedLinesWithDiagnosticPieces(*PD);
2991 Consumer->HandlePathDiagnostic(std::move(PD));
2995 /// Insert all lines participating in the function signature \p Signature
2996 /// into \p ExecutedLines.
2997 static void populateExecutedLinesWithFunctionSignature(
2998 const Decl *Signature, SourceManager &SM,
2999 FilesToLineNumsMap &ExecutedLines) {
3000 SourceRange SignatureSourceRange;
3001 const Stmt* Body = Signature->getBody();
3002 if (const auto FD = dyn_cast<FunctionDecl>(Signature)) {
3003 SignatureSourceRange = FD->getSourceRange();
3004 } else if (const auto OD = dyn_cast<ObjCMethodDecl>(Signature)) {
3005 SignatureSourceRange = OD->getSourceRange();
3009 SourceLocation Start = SignatureSourceRange.getBegin();
3010 SourceLocation End = Body ? Body->getSourceRange().getBegin()
3011 : SignatureSourceRange.getEnd();
3012 if (!Start.isValid() || !End.isValid())
3014 unsigned StartLine = SM.getExpansionLineNumber(Start);
3015 unsigned EndLine = SM.getExpansionLineNumber(End);
3017 FileID FID = SM.getFileID(SM.getExpansionLoc(Start));
3018 for (unsigned Line = StartLine; Line <= EndLine; Line++)
3019 ExecutedLines[FID].insert(Line);
3022 static void populateExecutedLinesWithStmt(
3023 const Stmt *S, SourceManager &SM,
3024 FilesToLineNumsMap &ExecutedLines) {
3025 SourceLocation Loc = S->getSourceRange().getBegin();
3028 SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc);
3029 FileID FID = SM.getFileID(ExpansionLoc);
3030 unsigned LineNo = SM.getExpansionLineNumber(ExpansionLoc);
3031 ExecutedLines[FID].insert(LineNo);
3034 /// \return all executed lines including function signatures on the path
3035 /// starting from \p N.
3036 static std::unique_ptr<FilesToLineNumsMap>
3037 findExecutedLines(SourceManager &SM, const ExplodedNode *N) {
3038 auto ExecutedLines = llvm::make_unique<FilesToLineNumsMap>();
3041 if (N->getFirstPred() == nullptr) {
3042 // First node: show signature of the entrance point.
3043 const Decl *D = N->getLocationContext()->getDecl();
3044 populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines);
3045 } else if (auto CE = N->getLocationAs<CallEnter>()) {
3046 // Inlined function: show signature.
3047 const Decl* D = CE->getCalleeContext()->getDecl();
3048 populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines);
3049 } else if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) {
3050 populateExecutedLinesWithStmt(S, SM, *ExecutedLines);
3052 // Show extra context for some parent kinds.
3053 const Stmt *P = N->getParentMap().getParent(S);
3055 // The path exploration can die before the node with the associated
3056 // return statement is generated, but we do want to show the whole
3058 if (const auto *RS = dyn_cast_or_null<ReturnStmt>(P)) {
3059 populateExecutedLinesWithStmt(RS, SM, *ExecutedLines);
3060 P = N->getParentMap().getParent(RS);
3063 if (P && (isa<SwitchCase>(P) || isa<LabelStmt>(P)))
3064 populateExecutedLinesWithStmt(P, SM, *ExecutedLines);
3067 N = N->getFirstPred();
3069 return ExecutedLines;
3072 std::unique_ptr<DiagnosticForConsumerMapTy>
3073 BugReporter::generateDiagnosticForConsumerMap(
3074 BugReport *report, ArrayRef<PathDiagnosticConsumer *> consumers,
3075 ArrayRef<BugReport *> bugReports) {
3077 if (!report->isPathSensitive()) {
3078 auto Out = llvm::make_unique<DiagnosticForConsumerMapTy>();
3079 for (auto *Consumer : consumers)
3080 (*Out)[Consumer] = generateEmptyDiagnosticForReport(report,
3081 getSourceManager());
3085 // Generate the full path sensitive diagnostic, using the generation scheme
3086 // specified by the PathDiagnosticConsumer. Note that we have to generate
3087 // path diagnostics even for consumers which do not support paths, because
3088 // the BugReporterVisitors may mark this bug as a false positive.
3089 assert(!bugReports.empty());
3090 MaxBugClassSize.updateMax(bugReports.size());
3091 std::unique_ptr<DiagnosticForConsumerMapTy> Out =
3092 generatePathDiagnostics(consumers, bugReports);
3097 MaxValidBugClassSize.updateMax(bugReports.size());
3099 // Examine the report and see if the last piece is in a header. Reset the
3100 // report location to the last piece in the main source file.
3101 AnalyzerOptions &Opts = getAnalyzerOptions();
3102 for (auto const &P : *Out)
3103 if (Opts.ShouldReportIssuesInMainSourceFile && !Opts.AnalyzeAll)
3104 P.second->resetDiagnosticLocationToMainFile();
3109 void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3110 const CheckerBase *Checker,
3111 StringRef Name, StringRef Category,
3112 StringRef Str, PathDiagnosticLocation Loc,
3113 ArrayRef<SourceRange> Ranges) {
3114 EmitBasicReport(DeclWithIssue, Checker->getCheckName(), Name, Category, Str,
3118 void BugReporter::EmitBasicReport(const Decl *DeclWithIssue,
3119 CheckName CheckName,
3120 StringRef name, StringRef category,
3121 StringRef str, PathDiagnosticLocation Loc,
3122 ArrayRef<SourceRange> Ranges) {
3123 // 'BT' is owned by BugReporter.
3124 BugType *BT = getBugTypeForName(CheckName, name, category);
3125 auto R = llvm::make_unique<BugReport>(*BT, str, Loc);
3126 R->setDeclWithIssue(DeclWithIssue);
3127 for (ArrayRef<SourceRange>::iterator I = Ranges.begin(), E = Ranges.end();
3130 emitReport(std::move(R));
3133 BugType *BugReporter::getBugTypeForName(CheckName CheckName, StringRef name,
3134 StringRef category) {
3135 SmallString<136> fullDesc;
3136 llvm::raw_svector_ostream(fullDesc) << CheckName.getName() << ":" << name
3138 BugType *&BT = StrBugTypes[fullDesc];
3140 BT = new BugType(CheckName, name, category);